阅读说明：本技术 电化学器件及其制造方法 (Electrochemical device and method for manufacturing the same ) 是由 李昌奎 李相英 于 2020-02-14 设计创作，主要内容包括：本发明涉及电化学器件及其制造方法。更具体地,涉及一种在由正极、隔膜及负极组成的电极组件中所述正极、隔膜及负极中的至少一种由凝胶高分子电解质形成且离子电导率不同的电化学器件及其制造方法。由于本发明的电化学器件的所述正极、隔膜及负极中的至少一种包含具有不同离子电导率的电解质,因此可提供对各个电极及隔膜优化的离子流,从而具有更有利于改善电化学器件的寿命特性及安全性的效果。(The present invention relates to an electrochemical device and a method for manufacturing the same. And more particularly, to an electrochemical device in which at least one of a cathode, a separator and an anode is formed of a gel polymer electrolyte and has different ionic conductivities in an electrode assembly composed of the cathode, the separator and the anode, and a method of manufacturing the same. Since at least one of the positive electrode, the separator, and the negative electrode of the electrochemical device of the present invention includes electrolytes having different ion conductivities, it is possible to provide ion flows optimized for the respective electrodes and separators, thereby having an effect more advantageous to improve the life characteristics and safety of the electrochemical device.)

1. An electrochemical device, characterized in that,

the method comprises the following steps:

a positive electrode-electrolyte combination comprising a first electrolyte on the positive electrode,

a negative electrode-electrolyte combination comprising a second electrolyte on the negative electrode, and

a separator-electrolyte combination comprising a third electrolyte on the separator;

at least one selected from the first electrolyte, the second electrolyte and the third electrolyte is a gel polymer electrolyte;

at least one selected from the first electrolyte, the second electrolyte and the third electrolyte has different ion conductivity.

2. The electrochemical device of claim 1,

one of the first electrolyte, the second electrolyte and the third electrolyte is a gel polymer electrolyte containing a cross-linked polymer matrix, a solvent and a dissociable salt, and the other two are liquid electrolytes containing a solvent and a dissociable salt.

3. The electrochemical device of claim 2,

the gel polyelectrolyte and the liquid electrolyte are different in one or more selected from the group consisting of a solvent type, a dissociable salt type, and a dissociable salt concentration.

4. The electrochemical device of claim 1,

two of the first electrolyte, the second electrolyte and the third electrolyte are gel polymer electrolytes containing a cross-linked polymer matrix, a solvent and a dissociable salt, and the other one is a liquid electrolyte containing a solvent and a dissociable salt.

5. The electrochemical device according to claim 4,

the two gel polyelectrolytes are different in one or more selected from the group consisting of the type of solvent, the type of dissociable salt, and the concentration of dissociable salt.

6. The electrochemical device according to claim 4,

the gel polyelectrolyte and the liquid electrolyte are different in one or more selected from the group consisting of a solvent type, a dissociable salt type, and a dissociable salt concentration.

7. The electrochemical device of claim 1,

the first electrolyte, the second electrolyte and the third electrolyte are all gel polymer electrolytes containing a cross-linked polymer matrix, a solvent and a dissociable salt, and one or more of the first electrolyte, the second electrolyte and the third electrolyte are different from one or more of the solvent type, the dissociable salt type and the dissociable salt concentration.

8. The electrochemical device according to any one of claims 1 to 7,

the cross-linked polymer matrix also comprises linear polymers, so that a semi-interpenetrating polymer network structure is formed.

9. The electrochemical device of claim 1,

at least one selected from the group consisting of the first electrolyte, the second electrolyte, and the third electrolyte has a difference in ionic conductivity of 0.1mS/cm or more.

10. The electrochemical device of claim 1,

at least one selected from the first electrolyte, the second electrolyte and the third electrolyte has different slopes obtained from an arrhenius diagram of temperature and ionic conductivity at 20 to 80 ℃.

11. The electrochemical device according to any one of claims 2 to 7,

the solvent is one or more mixed solvents selected from carbonate solvents, nitrile solvents, ester solvents, ether solvents, glycol dimethyl ether solvents, ketone solvents, alcohol solvents, aprotic solvents and water.

12. The electrochemical device of claim 11,

the carbonate solvent is one or a mixture of more than two of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate, ethylene carbonate, propylene carbonate and butylene carbonate, the nitrile solvent is one or a mixture of more than two of acetonitrile, succinonitrile, adiponitrile and sebaconitrile, the ester solvent is one or a mixture of more than two of methyl acetate, ethyl acetate, n-propyl acetate, 1-dimethylethyl acetate, methyl propionate, ethyl propionate, gamma-butyrolactone, decalactone, valerolactone, mevalonic lactone and caprolactone, the ether solvent is one or a mixture of more than two of dimethyl ether, dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran and tetrahydrofuran, the glycol dimethyl ether solvent is one or a mixture of more than two of glycol dimethyl ether, triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether, the ketone solvent is cyclohexanone, the alcohol solvent is one or a mixture of more than two of ethanol and isopropanol, and the aprotic solvent is one or a mixture of more than two of nitrile solvent, amide solvent, dioxolane solvent and sulfolane solvent.

13. The electrochemical device according to any one of claims 2 to 7,

the dissociable salt is selected from lithium hexafluorophosphate (LiPF)₆) Lithium tetrafluoroborate (LiBF)₄) Lithium hexafluoroantimonate (LiSbF)₆) Lithium hexafluoroarsenate (LiAsF)₆) Lithium difluoromethanesulfonate (LiC)₄F₉SO₃) Lithium perchlorate (LiClO)₄) Lithium aluminate (LiAlO)₂) Lithium aluminum tetrachloride (LiAlCl)₄) Lithium chloride (LiCl), lithium iodide (LiI), lithium bis (oxalato) borate (LiB (C)₂O₄)₂) Trifluoromethanesulfonylidine, trifluoromethanesulfonylidineAmine lithium (LiN (CxF)_2x+1SO₂)(CyF_2y+1SO₂) (wherein x and y are natural numbers)) and derivatives thereof.

14. The electrochemical device according to any one of claims 2 to 7,

the concentration of the salts differs by more than 0.1M.

15. The electrochemical device of claim 1,

the positive electrode includes a positive electrode active material layer, the negative electrode includes a negative electrode active material layer, and the positive electrode active material layer and the negative electrode active material layer include pores.

16. The electrochemical device of claim 15,

the positive electrode active material layer has a porosity of 5 to 30 vol%, and the negative electrode active material layer has a porosity of 10 to 35 vol%.

17. The electrochemical device of claim 16,

the positive electrode active material layer has a porosity of 10 to 20 vol%, and the negative electrode active material layer has a porosity of 15 to 25 vol%.

18. The electrochemical device of claim 1,

the positive electrode includes a positive electrode active material layer, the negative electrode is a lithium metal layer, and the positive electrode active material layer includes pores.

19. The electrochemical device of claim 18,

the positive electrode active material layer has a porosity of 5 to 30 vol%.

20. The electrochemical device of claim 19,

the positive electrode active material layer has a porosity of 10 to 20 vol%.

21. The electrochemical device of claim 1,

the electrochemical device is a primary battery or a secondary battery capable of performing an electrochemical reaction.

22. The electrochemical device of claim 1,

the electrochemical device is one selected from the group consisting of a lithium primary battery, a lithium secondary battery, a lithium sulfur battery, a lithium air battery, a sodium battery, an aluminum battery, a magnesium battery, a calcium battery, a zinc air battery, a sodium air battery, an aluminum air battery, a magnesium air battery, a calcium air battery, a supercapacitor, a dye-sensitized solar cell, a fuel cell, a lead storage battery, a nickel cadmium battery, a nickel hydrogen storage battery, and an alkaline battery.

23. A method of manufacturing an electrochemical device,

the method comprises the following steps:

a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating a first gel polyelectrolyte composition on a positive electrode and curing,

b) a step of manufacturing an electrode assembly by laminating the cathode-electrolyte combination, the separator and the anode, and

c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material;

the first electrolyte and the liquid electrolyte have different ionic conductivities.

24. A method of manufacturing an electrochemical device,

the method comprises the following steps:

a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode,

b) a step of manufacturing an electrode assembly by laminating a positive electrode, a separator, and the negative electrode-electrolyte combination; and

c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material;

the second electrolyte and the liquid electrolyte have different ionic conductivities.

25. A method of manufacturing an electrochemical device,

the method comprises the following steps:

a) a step of manufacturing a separator-electrolyte combination including a third electrolyte by coating a third gel polyelectrolyte composition on a separator and curing,

b) a step of manufacturing an electrode assembly by laminating a positive electrode, the separator-electrolyte combination and a negative electrode, and

c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material;

the third electrolyte and the liquid electrolyte have different ionic conductivities.

26. A method of manufacturing an electrochemical device,

the method comprises the following steps:

a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode,

b) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte assembly, a separator, and the negative electrode-electrolyte assembly; and

c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material;

at least one selected from the first electrolyte, the second electrolyte and the liquid electrolyte has different ion conductivity.

27. A method of manufacturing an electrochemical device,

the method comprises the following steps:

a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator,

b) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination and the negative electrode, and

c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material;

at least one selected from the first electrolyte, the third electrolyte and the liquid electrolyte has different ion conductivity.

28. A method of manufacturing an electrochemical device,

the method comprises the following steps:

a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator,

b) a step of manufacturing an electrode assembly by laminating the positive electrode, the separator-electrolyte combination and the negative electrode-electrolyte combination, and

c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material;

at least one selected from the second electrolyte, the third electrolyte and the liquid electrolyte has different ion conductivity.

29. The method of manufacturing an electrochemical device according to any one of claims 23 to 28,

at least one selected from the group consisting of the first electrolyte, the second electrolyte, the third electrolyte, and the liquid electrolyte is different in at least one selected from the group consisting of a type of solvent, a type of a dissociable salt, and a concentration of a dissociable salt.

30. The method of manufacturing an electrochemical device according to any one of claims 23 to 28,

the step b) is selected from:

b-1) laminating the positive electrode or the positive electrode-electrolyte combination, the separator or the separator-electrolyte combination, and the negative electrode or the negative electrode-electrolyte combination, and then cutting the laminated positive electrode or the positive electrode-electrolyte combination into a specific shape to manufacture an electrode assembly; or

b-2) cutting the positive electrode or the positive electrode-electrolyte combination, the separator or the separator-electrolyte combination, and the negative electrode or the negative electrode-electrolyte combination into specific shapes, respectively, and then laminating to manufacture an electrode assembly.

31. A method of manufacturing an electrochemical device,

the method comprises the following steps:

i) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, and

ii) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination, and the negative electrode-electrolyte combination;

at least one selected from the first electrolyte, the second electrolyte and the third electrolyte has different ion conductivity.

32. The method of manufacturing an electrochemical device according to claim 31,

at least one selected from the first electrolyte, the second electrolyte, and the third electrolyte is different in at least one selected from the group consisting of a type of solvent, a type of dissociable salt, and a concentration of dissociable salt.

33. The method of manufacturing an electrochemical device according to claim 31,

said ii) step is selected from:

ii-1) laminating the positive electrode-electrolyte assembly, the separator-electrolyte assembly and the negative electrode-electrolyte assembly, and cutting the laminated positive electrode-electrolyte assembly, separator-electrolyte assembly and negative electrode-electrolyte assembly into specific shapes; or

ii-2) a step of cutting the positive electrode-electrolyte assembly, the separator-electrolyte assembly, and the negative electrode-electrolyte assembly into specific shapes and laminating the cut products.

34. The method of manufacturing an electrochemical device according to claim 31,

after the step ii), further comprising a step iii) of sealing the electrode assembly with a packaging material.

Technical Field

The present invention relates to an electrochemical device and a method for manufacturing the same. And more particularly, to an electrochemical device in which at least one of a positive electrode, a separator and a negative electrode is composed of a gel polymer electrolyte (gel polymer electrolyte) and has different ionic conductivities in an electrode assembly composed of the positive electrode, the separator and the negative electrode, and a method of manufacturing the same.

In the electrochemical device according to an embodiment of the present invention, separate electrolytes may be introduced into the positive electrode, the separator, and the negative electrode, respectively, and an electrolyte having an optimized composition may be provided for each component, which has more advantageous effects in terms of improvement of life characteristics and safety of the electrochemical device by adjusting an optimized ion current to each electrode and separator.

Background

An electrode assembly composed of a negative electrode, a positive electrode, and a separator is mounted inside a cylindrical or square metal can or a pouch-shaped case of an aluminum laminate sheet, and an electrolyte is injected into the electrode assembly to manufacture a secondary battery.

As the electrolyte for the secondary battery, a liquid electrolyte in which a salt is dissolved in a nonaqueous organic solvent is mainly used. However, such a liquid electrolyte is very volatile in an organic solvent, and causes various problems such as deterioration of an electrode material and leakage of the electrolyte, and it is difficult to realize electrochemical devices of various forms having high stability.

Recently, in order to improve the stability of such liquid electrolytes, gel polymer electrolytes, solid polymer electrolytes, and the like, which do not have the problem of liquid leakage, have been developed.

Generally, a method of manufacturing a battery using a gel polymer electrolyte is as follows: after the electrode assembly is mounted inside a can or a pouch-shaped case, a precursor solution containing an electrolyte salt, an electrolyte solvent, a cross-linked polymer, and the like, which can form a gel polymer matrix, is injected at one time, and then gelated by a specific temperature and time treatment.

If the gel polymer electrolyte is introduced by such a conventional method, not only a long time is required for gelation, but also only one kind of electrolyte matrix can be uniformly formed in each electrode and separator. Also, it is difficult to impregnate a gel polymer matrix precursor solution into the inside of an electrode assembly composed of a high-density electrode for high energy density, which has been recently used.

Further, when the gel polymer electrolyte or the liquid electrolyte is injected at one time by the above-mentioned method, there occurs a problem that the electrolyte cannot be uniformly impregnated into the inside, or a problem that the electrolyte participates in oxidation or reduction reactions respectively due to the difference in energy levels of the positive electrode and the negative electrode to cause side reactions, thereby deteriorating the battery performance.

In order to suppress such side reactions of the electrolyte, it is necessary to use appropriate electrolytes for the positive electrode and the negative electrode, respectively, but this is impossible to achieve by the conventional method of injecting a liquid-phase electrolyte or a gel polymer electrolyte.

Documents of the prior art

Korean granted patent No. 10-0525278 (2005, 10 months and 25 days)

Disclosure of Invention

Problems to be solved by the invention

According to an embodiment of the present invention, a problem caused by the formation of the same electrolyte in the positive electrode, the negative electrode, and the separator is solved by injecting a liquid-phase electrolyte or a gel polymer electrolyte, and a problem of side reactions occurring in the positive electrode and the negative electrode is solved. Specifically, one embodiment of the present invention provides an electrochemical device in which at least one or two of the positive electrode, the separator, and the negative electrode are gel polymer electrolytes formed by a coating method, and the remaining electrolytes are injected liquid electrolytes, thereby making it possible to adjust ion current optimized for each electrode.

In addition, an embodiment of the present invention provides an electrochemical device in which gel polymer electrolytes are formed on a positive electrode, a separator, and a negative electrode by a coating method, and at least one of the gel polymer electrolytes is different in at least one selected from the group consisting of the type of a solvent, the type of a dissociable salt, and the concentration of the dissociable salt, so that the lifetime characteristics and safety of the electrochemical device can be further improved by adjusting an ion current optimized for each electrode and separator.

Further, an embodiment of the present invention provides an electrochemical device that can easily form a gel polymer electrolyte by a coating method such as coating or printing, and can be continuously produced and easily controlled in thickness.

Further, an embodiment of the present invention provides an electrochemical device in which a positive electrode, a separator, and a negative electrode each include a gel polymer electrolyte and have flexibility, and thus can be applied to a flexible device, and can also be applied to a non-planar curved surface, and can be formed into a battery shape by a method such as cutting, and thus can be formed into a battery shape freely.

Also, an embodiment of the present invention provides an electrochemical device including performance enhancers suitable for a positive electrode, a separator, and a negative electrode, respectively, and having more excellent charge/discharge efficiency and life characteristics of a battery.

Means for solving the problems

In order to achieve the object, an embodiment of the present invention provides an electrochemical device including: a positive electrode-electrolyte combination including a first electrolyte on a positive electrode, a negative electrode-electrolyte combination including a second electrolyte on a negative electrode, and a separator-electrolyte combination including a third electrolyte on a separator; at least one selected from the first electrolyte, the second electrolyte and the third electrolyte is a gel polymer electrolyte; at least one selected from the first electrolyte, the second electrolyte and the third electrolyte has different ion conductivity.

Another embodiment of the present invention provides a method of manufacturing an electrochemical device, including: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, a b) step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, a separator, and a negative electrode, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packing material; the first electrolyte and the liquid electrolyte have different ionic conductivities.

Another embodiment of the present invention provides a method of manufacturing an electrochemical device, including: a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, b) a step of manufacturing an electrode assembly by laminating a positive electrode, a separator, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; the second electrolyte and the liquid electrolyte have different ionic conductivities.

Another embodiment of the present invention provides a method of manufacturing an electrochemical device, including: a) a step of manufacturing a separator-electrolyte combination including a third electrolyte by coating a third gel polyelectrolyte composition on a separator and curing, b) a step of manufacturing an electrode assembly by laminating a positive electrode, the separator-electrolyte combination, and a negative electrode, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; the third electrolyte and the liquid electrolyte have different ionic conductivities.

Another embodiment of the present invention provides a method of manufacturing an electrochemical device, including: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, a b) step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, a separator, and the negative electrode-electrolyte combination, and a c) step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; at least one selected from the first electrolyte, the second electrolyte and the liquid electrolyte has different ion conductivity.

Another embodiment of the present invention provides a method of manufacturing an electrochemical device, including: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, a b) step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination, and a negative electrode, and a c) step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; at least one selected from the first electrolyte, the third electrolyte and the liquid electrolyte has different ion conductivity.

Another embodiment of the present invention provides a method of manufacturing an electrochemical device, including: a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, a b) step of manufacturing an electrode assembly by laminating a positive electrode, the separator-electrolyte combination, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; at least one selected from the second electrolyte, the third electrolyte and the liquid electrolyte has different ion conductivity.

Another embodiment of the present invention provides a method of manufacturing an electrochemical device, including: i) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, and ii) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination, and the negative electrode-electrolyte combination; at least one selected from the first electrolyte, the second electrolyte and the third electrolyte has different ion conductivity.

ADVANTAGEOUS EFFECTS OF INVENTION

In the electrochemical device according to an embodiment of the present invention, separate electrolytes may be introduced into the positive electrode, the separator, and the negative electrode, respectively, and an electrolyte having an optimized composition for each may be provided, thereby having more advantageous effects in improvement of life characteristics and safety of the electrochemical device by adjusting an optimized ion current to each electrode and separator.

Further, the electrochemical device according to an embodiment of the present invention includes at least one gel polyelectrolyte, and since the gel polyelectrolyte is in a crosslinked state, the components of the gel polyelectrolyte are not miscible with the components of the liquid electrolyte injected later, thereby having an effect of adjusting the ion current to the initially desired optimized ion current even if the electrochemical device is used for a long time.

In addition, even if the positive electrode, the separator, and the negative electrode all contain gel polymer electrolytes, there is little possibility of mixing and dissolving the electrolytes, and therefore, even if the electrochemical device is used for a long time, the ion current can be adjusted to the initially required optimized ion current.

In addition, the gel polymer electrolyte according to an embodiment of the present invention has inherent rheological characteristics of viscosity that can be applied directly to an electrode, and thus is easily impregnated into a high-density electrode for high energy density that is miscible and has a porosity of 20 vol% or less.

Further, the gel polymer electrolyte is used for at least one selected from the positive electrode, the separator and the negative electrode, and the gel polymer electrolyte can be applied not only by a coating process such as bar coating, spin coating, slit coating, dip coating and spray coating, but also by a printing process such as roll-to-roll printing, inkjet printing, gravure offset printing, aerosol printing, stencil printing and screen printing, thereby realizing continuous production and improving productivity. Also, the gel polyelectrolyte layer can be uniformly brought into close contact with the positive electrode, the separator, or the negative electrode, and can be uniformly impregnated into the central portion.

Further, since the gel polyelectrolyte layer can be formed by directly applying the gel polyelectrolyte layer to the electrode, the performance of the electrochemical device can be improved by stabilizing the interface between the electrode and the gel polyelectrolyte layer, and when the gel polyelectrolyte layer is applied to a flexible battery, the stable battery performance can be realized even if the form changes due to various external forces, and there is an effect of suppressing the danger that may be caused by the form deformation of the battery.

Detailed Description

The present invention will be described in further detail with reference to the following specific examples or examples. However, the following specific examples and examples are merely illustrative of the details of the present invention, and the present invention is not limited thereto, and may be implemented in various forms.

Also, unless otherwise defined, all technical and scientific terms have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the present invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Also, as used in the specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.

In the present invention, "electrode assembly" means that a positive electrode, a separator, and a negative electrode are laminated or laminated in a jelly-roll state, and it means a state before being sealed with a packaging material.

In the present invention, the "electrochemical device" refers to a state that can be used as a battery by sealing the electrode assembly with a packaging material.

In the present invention, for convenience, the electrolyte formed in the positive electrode is referred to as a first electrolyte, the electrolyte formed in the negative electrode is referred to as a second electrolyte, and the electrolyte formed in the separator is referred to as a third electrolyte, but the same electrolyte may be used except for at least one of them.

Specifically, for example, at least one of the first electrolyte, the second electrolyte, and the third electrolyte may be a gel polymer electrolyte, and the remaining two may be liquid electrolytes. At this time, the ionic conductivities of the gel polyelectrolyte and the liquid electrolyte may be different, respectively.

Two of the first electrolyte, the second electrolyte, and the third electrolyte may be gel polymer electrolytes, and the other may be a liquid electrolyte. At this time, the two gel polyelectrolytes have different ion conductivities, and one of the gel polyelectrolytes may have the same ion conductivity as the liquid electrolyte. Further, the two gel polymer electrolytes may have different ion conductivities, and the liquid electrolyte may have a different ion conductivity from the two gel polymer electrolytes. Further, the ionic conductivities of the two gel polyelectrolytes may be the same, and the ionic conductivities of the gel polyelectrolytes may be different from the ionic conductivity of the liquid electrolyte.

In the present invention, the term "electrolyte bonded body" refers to a structure in which an electrolyte is coated or impregnated on a positive electrode, a separator, or a negative electrode to be integrated. In this case, the electrolyte may be a gel polymer electrolyte or a liquid electrolyte, and at least one of the positive electrode, the separator, and the negative electrode may be a gel polymer electrolyte.

In the present invention, "the ionic conductivities are different" means that one or more selected from the group consisting of the kind of the solvent forming the electrolyte, the kind of the dissociable salt, and the concentration of the dissociable salt are different. More specifically, it may mean that the difference in ionic conductivity is 0.1mS/cm or more. The measurement method for ionic conductivity is described in further detail in the following examples.

In the present invention, "the type of solvent is different", "the type of salt is different", or "the concentration of salt is different" can be confirmed by infrared spectroscopic analysis. Specifically, in the case of coating or impregnating electrolytes different in the kind of solvent or the kind of salt, the positive electrode, the negative electrode, and the separator are separated from the electrode assembly in a state where the initial formation (formation) step is completed by applying a charge-discharge current, and each is analyzed by a Fourier transform infrared spectroscopy (670-IR, Varian), and the kind or concentration of the substance can be distinguished from the peak intensity derived from the substance characteristics by an absorption spectrum obtained by splitting reflected light when infrared light is irradiated.

If necessary, the analysis can be confirmed by X-ray photoelectron analysis, inductively coupled plasma mass spectrometry, nuclear magnetic resonance spectroscopy, time-of-flight secondary ion mass spectrometry, or the like. The following examples further describe the measurement method thereof in detail.

In the present invention, the "gel polyelectrolyte" may be formed by coating a gel polyelectrolyte composition containing a crosslinkable monomer, an initiator, a dissociable salt, and a solvent and curing the composition. The phrase "different types of solvents", "different types of salts", or "different concentrations of salts" means that the types of solvents, the types of salts, and the concentrations of salts used in the gel polymer electrolyte composition are different.

Specifically, an embodiment of the present invention relates to an electrochemical device including: a positive electrode-electrolyte combination including a first electrolyte on a positive electrode, a negative electrode-electrolyte combination including a second electrolyte on a negative electrode, and a separator-electrolyte combination including a third electrolyte on a separator; at least one selected from the first electrolyte, the second electrolyte and the third electrolyte is a gel polymer electrolyte; at least one selected from the first electrolyte, the second electrolyte and the third electrolyte has different ion conductivity.

According to an embodiment of the present invention, one of the first electrolyte, the second electrolyte and the third electrolyte is a gel polymer electrolyte including a cross-linked polymer matrix, a solvent and a dissociable salt, and the other two may be liquid electrolytes including a solvent and a dissociable salt. In this case, the ionic conductivities of the gel polyelectrolyte and the liquid electrolyte may be different. The ionic conductivity may be different depending on a monomer contained in the gel polyelectrolyte, or may be different depending on one or more selected from the group consisting of a kind of a solvent used for the gel polyelectrolyte and the liquid electrolyte, a kind of a dissociable salt, and a concentration of the dissociable salt.

According to an embodiment of the present invention, two of the first electrolyte, the second electrolyte, and the third electrolyte may be gel polymer electrolytes including a cross-linked polymer matrix, a solvent, and a dissociable salt, and the other may be a liquid electrolyte including a solvent and a dissociable salt. In this case, the two gel polymer electrolytes may be the same, or one or more selected from the group consisting of the type of solvent, the type of dissociable salt, and the concentration of dissociable salt may be different. The gel polyelectrolyte and the liquid electrolyte may be different in one or more selected from the group consisting of a solvent type, a dissociable salt type, and a dissociable salt concentration.

According to an embodiment of the present invention, the first electrolyte, the second electrolyte, and the third electrolyte are all gel polymer electrolytes including a cross-linked polymer matrix, a solvent, and a dissociable salt, and one or more selected from the group consisting of a type of the solvent, a type of the dissociable salt, and a concentration of the dissociable salt may be different.

According to an embodiment of the present invention, the cross-linked polymer matrix further includes a linear polymer, so that it may have a semi-interpenetrating polymer network (semi-IPN) structure.

According to an embodiment of the present invention, the difference in ionic conductivity of at least one selected from the first electrolyte, the second electrolyte and the third electrolyte may be 0.1mS/cm or more.

According to an embodiment of the present invention, the slope obtained in an arrhenius plot of the ionic conductivity and the temperature at 20 to 80 ℃ of at least one selected from the first electrolyte, the second electrolyte and the third electrolyte may be different. Since the slope of the arrhenius diagram refers to activation energy related to ion movement in the electrolyte, the difference in the solvent type, the salt type, and the salt concentration can be taken into account by the difference in the slope.

According to an embodiment of the present invention, the solvent may be one or a mixture of two or more selected from a Carbonate (Carbonate) solvent, a nitrile solvent, an ester solvent, an ether solvent, a glyme (glyme) solvent, a ketone solvent, an alcohol solvent, an aprotic solvent, and water.

According to an embodiment of the present invention, the carbonate-based solvent is one or a mixture of two or more selected from the group consisting of dimethyl carbonate, diethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, methylethyl carbonate, ethylene carbonate, propylene carbonate, and butylene carbonate.

The nitrile solvent may be one or more selected from acetonitrile (acetonitrile), succinonitril (succinonitril), adiponitrile (adiponitrile), and sebaconitrile (sebaconitril).

The ester solvent is one or a mixture of two or more selected from methyl acetate (methyl acetate), ethyl acetate (ethyl acetate), n-propyl acetate (n-propyl acetate), 1-dimethylethyl acetate (1, 1-dimethylethyl acetate), methyl propionate (methyl propionate), ethyl propionate (ethyl propionate), gamma-butyrolactone (gamma-butyrolactone), decanolactone (decanolide), valerolactone (valrolone), mevalonolactone (mevalonolactone), and caprolactone (caprolactone).

The ether solvent is one or more selected from dimethyl ether, dibutyl ether, tetraethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dimethoxyethane (dimethoxyethane), 2-methyltetrahydrofuran and tetrahydrofuran.

The glyme solvent is one or a mixture of more than two of glyme, triglyme and tetraglyme.

The ketone solvent is cyclohexanone.

The alcohol solvent is one or a mixture of more than two of ethanol and isopropanol.

The aprotic solvent may be one or a mixture of two or more selected from nitrile solvents, amide solvents, dioxolane solvents and sulfolane solvents.

According to an embodiment of the invention, the dissociable salt may be selected from lithium hexafluorophosphate (LiPF)₆) Lithium tetrafluoroborate (LiBF)₄) Lithium hexafluoroantimonate (LiSbF)₆) Lithium hexafluoroarsenate (LiAsF)₆) Lithium difluoromethanesulfonate (LiC)₄F₉SO₃) Lithium perchlorate (LiClO)₄) Lithium aluminate (LiAlO)₂) Lithium aluminum tetrachloride (Li AlCl)₄) Lithium chloride (LiCl), lithium iodide (LiI), lithium bis (oxalato) borate (LiB (C)₂O₄)₂) Lithium trifluoromethanesulfonylimide (LiN (CxF)_2x+1SO₂)(CyF_2y+1SO₂) (wherein x and y are natural numbers) and one or a mixture of two or more of their derivatives.

According to an embodiment of the invention, the concentration of the salts may differ by more than 0.1M.

According to one embodiment of the present invention, the positive electrode includes a positive electrode active material layer, the negative electrode includes a negative electrode active material layer, and the positive electrode active material layer and the negative electrode active material layer may include pores.

According to an embodiment of the present invention, the porosity (porosity) of the positive electrode active material layer may be 5 to 30 vol%, and the porosity (porosity) of the negative electrode active material layer may be 10 to 35 vol%.

According to an embodiment of the present invention, the porosity (porosity) of the positive electrode active material layer may be 10% by volume to 20% by volume, and the porosity (porosity) of the negative electrode active material layer may be 15% by volume to 25% by volume.

According to an embodiment of the present invention, the positive electrode includes a positive electrode active material layer, the negative electrode includes a lithium metal layer, and the positive electrode active material layer may include pores.

According to an embodiment of the present invention, the porosity (porosity) of the positive electrode active material layer may be 5 to 30 vol%.

According to an embodiment of the present invention, the porosity (porosity) of the positive electrode active material layer may be 10 to 20 vol%.

According to an embodiment of the present invention, the electrochemical device may be a primary battery or a secondary battery that may perform an electrochemical reaction.

According to an embodiment of the present invention, the electrochemical device may be one selected from the group consisting of a lithium primary battery, a lithium secondary battery, a lithium sulfur battery, a lithium air battery, a sodium battery, an aluminum battery, a magnesium battery, a calcium battery, a zinc air battery, a sodium air battery, an aluminum air battery, a magnesium air battery, a calcium air battery, a supercapacitor, a dye-sensitized solar cell, a fuel cell, a lead storage battery, a nickel cadmium battery, a nickel hydrogen storage battery, and an alkaline battery.

Another embodiment of the present invention is a method for manufacturing an electrochemical device, including as a first embodiment: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, b) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, a separator, and a negative electrode, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; the first electrolyte and the liquid electrolyte have different ionic conductivities.

Another embodiment of the present invention is a method for manufacturing an electrochemical device, including as a second embodiment: a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, b) a step of manufacturing an electrode assembly by laminating a positive electrode, a separator, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; the second electrolyte and the liquid electrolyte have different ionic conductivities.

Another embodiment of the present invention is a method for manufacturing an electrochemical device, including as a third embodiment: a) a step of manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, b) a step of manufacturing an electrode assembly by laminating a positive electrode, the separator-electrolyte combination, and a negative electrode, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; the third electrolyte and the liquid electrolyte have different ionic conductivities.

Another embodiment of the present invention is a method for manufacturing an electrochemical device, including as a fourth embodiment: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, b) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, a separator, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; at least one selected from the first electrolyte, the second electrolyte and the liquid electrolyte has different ion conductivity.

Another embodiment of the present invention is a method for manufacturing an electrochemical device, including as a fifth embodiment: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, b) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination, and a negative electrode, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; at least one selected from the first electrolyte, the third electrolyte and the liquid electrolyte may have different ionic conductivities.

Another embodiment of the present invention is a method for manufacturing an electrochemical device, including as a sixth embodiment: a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, b) a step of manufacturing an electrode assembly by laminating a positive electrode, the separator-electrolyte combination, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material; at least one selected from the second electrolyte, the third electrolyte, and the liquid electrolyte may have different ionic conductivities.

According to an embodiment of the manufacturing method of the present invention, the step b) may be selected from: b-1) laminating the positive electrode or the positive electrode-electrolyte combination, the separator or the separator-electrolyte combination, and the negative electrode or the negative electrode-electrolyte combination, and then cutting the laminated positive electrode or the positive electrode-electrolyte combination into a specific shape to manufacture an electrode assembly; or b-2) a step of manufacturing an electrode assembly by laminating after cutting the positive electrode or the positive electrode-electrolyte combination, the separator or the separator-electrolyte combination, and the negative electrode or the negative electrode-electrolyte combination into specific shapes, respectively.

According to one embodiment of the production method of the present invention, at least one selected from the group consisting of the first electrolyte, the second electrolyte, the third electrolyte, and the liquid electrolyte may be different in at least one selected from the group consisting of a type of solvent, a type of a dissociable salt, and a concentration of the dissociable salt.

Another embodiment of the present invention is a method for manufacturing an electrochemical device, including as a seventh embodiment: i) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, and ii) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination, and the negative electrode-electrolyte combination; at least one selected from the first electrolyte, the second electrolyte, and the third electrolyte may have different ionic conductivities.

In one embodiment of the production method, at least one selected from the group consisting of the first electrolyte, the second electrolyte, and the third electrolyte may be different in at least one selected from the group consisting of a type of solvent, a type of a dissociable salt, and a concentration of a dissociable salt.

In one embodiment of the manufacturing method, the ii) step may be selected from: ii-1) laminating the positive electrode-electrolyte assembly, the separator-electrolyte assembly and the negative electrode-electrolyte assembly, and cutting the laminated positive electrode-electrolyte assembly, separator-electrolyte assembly and negative electrode-electrolyte assembly into specific shapes; or ii-2) a step of cutting the positive electrode-electrolyte assembly, the separator-electrolyte assembly, and the negative electrode-electrolyte assembly into specific shapes and laminating the cut products.

In one embodiment of the manufacturing method, after the step of ii), a step of iii) sealing the electrode assembly with a packaging material is further included.

Hereinafter, an embodiment of the present invention will be described in further detail.

First, an electrochemical device according to an embodiment of the present invention will be described in further detail.

An electrochemical device according to an embodiment of the present invention includes: a positive-electrode-electrolyte combination including a first electrolyte on the positive electrode, a negative-electrode-electrolyte combination including a second electrolyte on the negative electrode, and a separator-electrolyte combination including a third electrolyte on the separator.

In this case, at least one selected from the first electrolyte, the second electrolyte and the third electrolyte is a gel polymer electrolyte, and at least one selected from the first electrolyte, the second electrolyte and the third electrolyte has different ion conductivities.

Specifically, according to the first embodiment of the electrochemical device of the present invention, one of the first electrolyte, the second electrolyte, and the third electrolyte is a gel polymer electrolyte including a cross-linked polymer matrix, a solvent, and a dissociable salt, and the remaining two may be liquid electrolytes including a solvent and a dissociable salt. At this time, the ionic conductivities of the gel polyelectrolyte and the liquid electrolyte may be different. More specifically, the gel polyelectrolyte and the liquid electrolyte may be different in one or more selected from the group consisting of a type of solvent, a type of dissociable salt, and a concentration of the dissociable salt.

More specifically, according to the first embodiment, for example, the first electrolyte may be a gel polymer electrolyte, and the second electrolyte and the third electrolyte may be liquid electrolytes. The gel polymer electrolyte of the first electrolyte may have an ion conductivity different from that of the liquid electrolytes of the second and third electrolytes. In this case, the second electrolyte and the third electrolyte may be the same liquid electrolyte.

Alternatively, the second electrolyte may be a gel polymer electrolyte, and the first electrolyte and the third electrolyte may be liquid electrolytes. The gel polymer electrolyte of the second electrolyte may have an ion conductivity different from that of the liquid electrolytes of the first and third electrolytes. In this case, the first electrolyte and the third electrolyte may be the same liquid electrolyte.

Alternatively, the third electrolyte is a gel polymer electrolyte, and the first electrolyte and the second electrolyte may be liquid electrolytes. The gel polymer electrolyte of the third electrolyte may have an ion conductivity different from that of the liquid electrolytes of the first and second electrolytes. In this case, the first electrolyte and the second electrolyte may be the same liquid electrolyte.

According to a second embodiment of the electrochemical device of the present invention, two of the first electrolyte, the second electrolyte, and the third electrolyte are gel polymer electrolytes including a cross-linked polymer matrix, a solvent, and a dissociable salt, and the other may be a liquid electrolyte including a solvent and a dissociable salt. In this case, the ionic conductivities of the two gel polyelectrolytes may be the same, and the ionic conductivities of the gel polyelectrolytes may be different from the ionic conductivity of the liquid electrolyte. Alternatively, the two gel polyelectrolytes may have different ion conductivities, and one of the two gel polyelectrolytes may have the same ion conductivity as the liquid electrolyte. Alternatively, the two gel polyelectrolytes may have different ion conductivities, and the liquid electrolyte may have a different ion conductivity from the two gel polyelectrolytes.

More specifically, according to the second embodiment, for example, the first electrolyte and the second electrolyte may be gel polymer electrolytes, and the third electrolyte may be a liquid electrolyte. In this case, the ionic conductivity of the gel polymer electrolyte of the first electrolyte may be different from the ionic conductivity of the gel polymer electrolyte of the second electrolyte, and the ionic conductivity of the liquid electrolyte of the third electrolyte may be different from the ionic conductivities of the first electrolyte and the second electrolyte.

Alternatively, the first electrolyte and the second electrolyte may be gel polymer electrolytes, and the third electrolyte may be a liquid electrolyte. In this case, the ionic conductivity of the gel polymer electrolyte of the first electrolyte may be different from the ionic conductivity of the gel polymer electrolyte of the second electrolyte, and the ionic conductivity of the liquid electrolyte of the third electrolyte may be the same as the ionic conductivity of one of the first electrolyte and the second electrolyte.

Alternatively, the first electrolyte and the second electrolyte may be gel polymer electrolytes, and the third electrolyte may be a liquid electrolyte. In this case, the ionic conductivity of the gel polymer electrolyte of the first electrolyte may be the same as the ionic conductivity of the gel polymer electrolyte of the second electrolyte, and the ionic conductivity of the liquid electrolyte of the third electrolyte may be different from the ionic conductivities of the first electrolyte and the second electrolyte.

As described in the second embodiment, the two gel polyelectrolytes may have different ion conductivities, and one or more selected from the group consisting of the type of solvent, the type of salt that can be dissociated, and the concentration of salt that can be dissociated may be different between the two gel polyelectrolytes.

In the case where the ionic conductivities of the gel polyelectrolyte and the liquid electrolyte are different from each other, one or more selected from the group consisting of the type of the solvent, the type of the dissociable salt, and the concentration of the dissociable salt may be different between the gel polyelectrolyte and the liquid electrolyte.

According to a third aspect of the electrochemical device of the present invention, each of the first electrolyte, the second electrolyte, and the third electrolyte is a gel polymer electrolyte including a crosslinked polymer matrix, a solvent, and a dissociable salt, and one or more of the solvents, the dissociable salts, and the concentrations of the dissociable salts may be different.

More specifically, in the third embodiment, for example, the first electrolyte, the second electrolyte, and the third electrolyte are all gel polymer electrolytes, and the ion conductivity of the first electrolyte may be different from the ion conductivity of the second electrolyte and the third electrolyte.

Alternatively, the first electrolyte, the second electrolyte, and the third electrolyte may be gel polymer electrolytes, and the ion conductivity of the second electrolyte may be different from the ion conductivity of the first electrolyte and the third electrolyte.

Alternatively, the first electrolyte, the second electrolyte, and the third electrolyte may be gel polymer electrolytes, and the ion conductivity of the third electrolyte may be different from the ion conductivities of the first electrolyte and the second electrolyte.

Alternatively, the first electrolyte, the second electrolyte and the third electrolyte may all be gel polymer electrolytes, and the ion conductivities of the first electrolyte, the second electrolyte and the third electrolyte are all different.

The above aspects are merely intended to specifically illustrate one embodiment of the present invention, and the present invention is not limited to the first to third embodiments, and it is obvious that various modifications can be made with reference to the first to third embodiments.

In the first to third embodiments, the reason why the ionic conductivities of the gel polyelectrolytes are different is that the gel polyelectrolytes of the present invention are gel polyelectrolytes formed by coating and curing the gel polyelectrolytes by a coating method. Further, the ionic conductivity between the electrolytes may be made different by making different one or more selected from the group consisting of the kind of solvent, the kind of dissociable salt, and the concentration of dissociable salt.

In one embodiment of the present invention, the first electrolyte, the second electrolyte and the third electrolyte may be gel polymer electrolytes or liquid electrolytes, and at least one of them may be gel polymer electrolytes.

And, at least one of them has different ionic conductivity, more specifically, the difference of ionic conductivity may be 0.1mS/cm or more. Under the condition that the difference of the ionic conductivity is more than 0.1mS/cm, the charging and discharging efficiency and the service life of the battery can be increased, and meanwhile, the safety of the battery can be improved.

At least one selected from the first electrolyte, the second electrolyte and the third electrolyte is characterized in that the slopes obtained in an arrhenius graph of the temperature and the ionic conductivity under the condition of 20-80 ℃ are different. Under the condition that the slopes of the Arrhenius graphs are different, the charging and discharging efficiency and the service life of the battery can be increased, and meanwhile, the safety of the battery can be improved.

The liquid electrolyte is not particularly limited as long as it is a liquid electrolyte commonly used in the art, and specifically, for example, may include a solvent and a dissociable salt.

Specifically, for example, the gel polyelectrolyte may include a crosslinked polymer matrix, a solvent, and a dissociable salt. The gel polymer electrolyte may be applied not only by a coating method such as bar coating, spin coating, slot coating, dip coating, and spray coating, but also by a printing method such as inkjet printing, gravure offset printing, aerosol printing, stencil printing, and Screen printing (Screen printing), so that the gel polymer electrolyte can be continuously produced.

The gel polyelectrolyte can realize photo-crosslinking combination or thermal crosslinking combination of crosslinkable monomers and derivatives thereof by using an initiator so as to form a crosslinked polymer matrix. Specifically, a gel polymer electrolyte composition containing a crosslinkable monomer and its derivative, an initiator, a solvent and a dissociable salt is coated and crosslinked by ultraviolet irradiation or application of heat, so that a liquid electrolyte or the like containing a solvent and a dissociable salt is uniformly distributed in a network structure of a crosslinked polymer matrix, and an evaporation process of the solvent may be unnecessary.

Preferably, the gel polyelectrolyte composition may have a viscosity suitable for a printing process, and particularly, for example, the viscosity measured at a temperature of 25 ℃ using a bohler viscometer is 0.1 to 10000000cps, preferably 1.0 to 1000000cps, and more preferably may be 1.0 to 100000cps, and thus the above range may be preferred because it is suitably applied to a printing process within the range, but is not limited thereto.

In the gel polyelectrolyte composition, comprising, relative to 100% by weight of the total composition: 1-50 wt% of crosslinkable monomer and its derivative, specifically, 2-40 wt% of crosslinkable monomer and its derivative can be included, but not limited thereto. Also, the content of the initiator may be 0.01 to 50% by weight, specifically, 0.01 to 20% by weight, more specifically, 0.1 to 10% by weight, but is not limited thereto. The electrolyte may contain 1 to 95 wt% of the liquid electrolyte mixed with the solvent and the dissociable salt, specifically 1 to 90 wt%, more specifically 2 to 80 wt%, but is not limited thereto.

The crosslinkable monomer may be used using a monomer having two or more functional groups or a mixture of a monomer having two functional groups and a monomer having one functional group, and may be used without limitation as long as it can achieve photo-crosslinking or thermal crosslinking. More specifically, the crosslinkable monomer may be one or a mixture of two or more selected from the group consisting of an acrylate monomer, an acrylic monomer, a sulfonic acid monomer, a phosphoric acid monomer, a perfluoro monomer, and a vinylcyanide monomer.

Specifically, for example, the monomer having two or more functional groups may be one or a mixture of two or more selected from the group consisting of polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, triethylene glycol diacrylate, triethylene glycol dimethacrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated trimethylolpropane trimethacrylate, ethoxylated bisphenol a diacrylate, ethoxylated bisphenol a dimethacrylate, and the like.

The monomer having one functional group may be one or a mixture of two or more selected from methyl methacrylate, ethyl methacrylate, butyl methacrylate, methyl acrylate, butyl acrylate, ethylene glycol methyl ether methacrylate, acrylonitrile, vinyl acetate, vinyl chloride, vinyl fluoride, and the like.

More specifically, the monomer may be ethoxylated trimethylolpropane triacrylate alone, or may be used by mixing the ethoxylated trimethylolpropane triacrylate with one or more selected from the group consisting of other monomers having two or more functional groups and monomers having one functional group.

The initiator may be used without limitation as long as it is a photoinitiator or a thermal initiator commonly used in the art.

The liquid electrolyte is meant to comprise a dissociable salt and a solvent.

Although not limited, specifically, the dissociable salt may be selected from, for example, lithium hexafluorophosphate (LiPF)₆) Lithium tetrafluoroborate (LiBF)₄) Lithium hexafluoroantimonate (LiSbF)₆) Lithium hexafluoroarsenate (LiAsF)₆) Lithium difluoromethanesulfonate (LiC)₄F₉SO₃) Lithium perchlorate (LiClO)₄) Lithium aluminate (LiAlO)₂) Lithium aluminum tetrachloride (LiAlCl)₄) Chlorine, chlorineLithium iodide (LiCl), lithium iodide (LiI), lithium bis (oxalato) borate (LiB (C)₂O₄)₂) Lithium trifluoromethanesulfonylimide (LiN (CxF)_2x+1SO₂)(CyF_2y+1SO₂) (wherein x and y are natural numbers) and derivatives thereof, and the like. The concentration of the dissociable salt is 0.1 to 10.0M, more specifically 1 to 5M, but not limited thereto.

More specifically, the dissociable salt may be one or a mixture of two or more selected from lithium hexafluorophosphate, lithium bis (oxalato) borate, lithium trifluoromethanesulfonylimide, derivatives thereof, and the like.

The solvent may use one or a mixed solvent of two or more selected from organic solvents such as carbonate solvents, nitrile solvents, ester solvents, ether solvents, ketone solvents, glycol dimethyl ether solvents, alcohol solvents, and aprotic solvents, and water.

As the carbonate-based solvent, dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethylpropyl carbonate (EPC), methylethyl carbonate (MEC), Ethylene Carbonate (EC), Propylene Carbonate (PC), Butylene Carbonate (BC), and the like can be used.

The nitrile solvent may use acetonitrile (acetonitrile), succinonitrile (succinonitile), adiponitrile (adiponitrile), sebaconitrile (sebaconitile) and the like.

The ester-based solvent may use methyl acetate (methyl acetate), ethyl acetate (ethyl acetate), n-propyl acetate (n-propyl acetate), 1-dimethylethyl acetate (1, 1-dimethylethyl acetate), methyl propionate (methyl propionate), ethyl propionate (ethyl propionate), γ -butyrolactone (γ -butyllactone), decanolactone (decanolide), valerolactone (valnolactone), mevalonolactone (mevalonolactone), caprolactone (caprolactone), and the like.

The ether solvent may be dimethyl ether, dibutyl ether, tetraglyme, diethylene glycol dimethyl ether, dimethoxyethane, 2-methyltetrahydrofuran, tetrahydrofuran, etc., and the ketone solvent may be cyclohexanone, etc.

As the glyme-based solvent, glyme, triglyme, tetraglyme, and the like can be used.

The alcohol solvent may be ethanol, isopropanol, etc., and the aprotic solvent may be a nitrile such as R — CN (R is a linear, branched or cyclic hydrocarbon group of C2 to C20 and may include a double bond, an aromatic ring or an ether bond), an amine such as dimethylformamide, a dioxolane such as 1, 3-dioxolane, a sulfolane (sulfolane), etc.

The solvent may be used alone or in combination of one or more, and the mixing ratio when the one or more solvents are used in combination may be appropriately adjusted according to the desired battery performance, as can be easily understood by those skilled in the art.

More specifically, the solvent may be one or a mixture of two or more selected from dimethyl carbonate, ethylene carbonate, propylene carbonate, methylpropyl carbonate, methylethyl carbonate, succinonitrile, 1, 3-dioxolane, dimethylacetamide, sulfolane, tetraethylene glycol dimethyl ether, dimethoxyethane, and the like.

And, the cross-linked polymer matrix further includes a linear polymer, thereby having a semi-interpenetrating polymer network (semi-IPN) structure. In this case, it has excellent flexibility and is highly resistant to stress such as bending when used as a battery, so that the battery can be normally driven without causing deterioration in performance. Therefore, it can be applied to flexible batteries and the like.

The linear polymer may be used without limitation as long as it is a polymer that can be easily mixed with the crosslinkable monomer and impregnated with a liquid electrolyte. Specifically, for example, the linear polymer may be one or a combination of two or more selected from polyvinylidene fluoride (poly (vinylidene fluoride), PVdF), polyvinylidene fluoride-hexafluoropropylene (poly (vinylidene fluoride) -co-hexafluoropropylene, PVdF-co-HFP), polymethyl methacrylate (PMMA), Polystyrene (Polystyrene, PS), polyvinyl acetate (polyvinyl acetate, PVA), Polyacrylonitrile (Polyacrylonitrile, PAN), Polyethylene oxide (PEO), and the like, but is not limited thereto.

The linear polymer may be included in an amount of 1 to 90 wt% with respect to the weight of the crosslinked polymer matrix. Specifically, 1 to 80 wt%, 1 to 70 wt%, 1 to 60 wt%, 1 to 50 wt%, 1 to 40 wt%, 1 to 30 wt% may be included. That is, in the case where the polymer matrix is a semi-interpenetrating polymer network (semi-IPN) structure, the weight ratio of the crosslinkable polymer to the linear polymer may be 99: 1 to 10: 90 range. When the linear polymer is contained in the above range, the crosslinked polymer matrix can maintain appropriate mechanical strength and ensure flexibility. Thus, when applied to a flexible battery, stable battery performance can be achieved even if the shape is deformed by various external forces, and the risk of ignition, explosion, and the like of the battery that may be caused by deformation of the form of the battery can be suppressed.

Also, the gel polyelectrolyte composition may further include the inorganic particles as needed. The inorganic particles enable printing of the gel polymer electrolyte composition by controlling rheological characteristics such as viscosity of the gel polymer electrolyte composition.

The inorganic particle may be used to improve the ionic conductivity and mechanical strength of an electrolyte, and may be a porous particle, but is not limited thereto. For example, a metal oxide, an oxycarbide, a carbon-based material, an organic-inorganic composite, or the like may be used alone, or two or more of them may be mixed and used. More specifically, for example, the inorganic particles may be selected from SiO₂、Al₂O₃、TiO₂、BaTiO₃、Li₂O、LiF、LiOH、Li₃N、BaO、Na₂O、Li₂CO₃、CaCO₃、LiAlO₂、SrTiO₃、SnO₂、CeO₂、MgO、NiO、CaO、Zn O、ZrO₂And SiC, and the like. Although not limited thereto, by using the inorganic particles, not only the affinity with an organic solvent but also the thermal stability of an electrochemical device can be improved.

The average diameter of the inorganic particles is not limited, but may be 0.001 μm to 10 μm. Specifically, the average diameter of the inorganic particles may be 0.1 μm to 10 μm, and more specifically, may be 0.1 μm to 5 μm. When the average diameter of the inorganic particles satisfies the range, excellent mechanical strength and stability of an electrochemical device may be achieved.

The content of the inorganic particles in the gel polymer electrolyte composition is 1 to 50 wt%, more specifically 5 to 40 wt%, and even more specifically 10 to 30 wt%, and the amount thereof may satisfy the above-mentioned viscosity range of 0.1 to 10000000cps, more preferably 1.0 to 1000000cps, and even more preferably 1.0 to 100000cps, but is not limited thereto.

(1) Positive electrode-electrolyte combination

According to one embodiment of the present invention, the positive electrode is a structure in which a positive electrode active material layer is formed on a positive electrode current collector.

The positive electrode current collector may be used without limitation as long as it is a substrate excellent in conductivity used in the art, and may be configured to include one selected from a conductive metal, a conductive metal oxide, and the like. The current collector may be formed entirely of a conductive material, or may be formed by coating one or both surfaces of a substrate with a conductive metal, a conductive metal oxide, a conductive polymer, or the like. Also, the current collector may be composed of a flexible substrate, and thus may be easily bent, so that a flexible electronic device may be provided. And, it may be made of a material having a restoring force capable of restoring its original form after being bent. More specifically, for example, the current collector may be composed of a polymer substrate coated with aluminum, stainless steel, copper, nickel, iron, lithium, cobalt, titanium, nickel foam, copper foam, and a conductive metal, or the like, but is not limited thereto.

The positive electrode active material layer may be formed of an active material layer containing a positive electrode active material and a binder.

The thickness of the positive electrode active material layer is not limited, but may be 0.01 to 500 μm, and more specifically, may be 1 to 200 μm, but is not limited thereto.

The active material layer in the positive electrode active material layer may be formed by coating a positive electrode active material composition including a positive electrode active material, a binder, and a solvent. Alternatively, the positive electrode having the positive electrode active material layer formed thereon may be prepared by casting the positive electrode active material composition on a separate support, and laminating a film obtained by peeling the film from the support on the current collector.

Any positive electrode active material commonly used in the art may be used without limitation. Specifically, for example, a lithium primary battery or a secondary battery may use a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound). The positive electrode active material of the present invention may be in the form of powder.

Specifically, the positive electrode active material may be one or more of a composite oxide of lithium and a metal selected from one or a combination of two or more of cobalt, manganese, nickel, and the like. Although not limited thereto, as a specific example, a compound represented by one of the following chemical formulae may be used. LiaA1-bRbD2 (in the formula, 0.90. ltoreq. a.ltoreq.1.8 and 0. ltoreq. b.ltoreq.0.5); LiaE1-bRbO2-cDc (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, b is more than or equal to 0 and less than or equal to 0.5, and c is more than or equal to 0 and less than or equal to 0.05); LiE2-bRbO4-cDc (in the formula, b is more than or equal to 0 and less than or equal to 0.5, and c is more than or equal to 0 and less than or equal to 0.05); LiaN i1-b-cCobRcD alpha (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and alpha is more than or equal to 0 and less than or equal to 2); lia Ni1-b-cCobRcO 2-alpha Z alpha (in the formula, 0.90. ltoreq. a.ltoreq.1.8, 0. ltoreq. b.ltoreq.0.5, 0. ltoreq. c.ltoreq.0.05, and 0< alpha < 2); LiaNi1-b-cCobRcO 2-alpha Z2 (in the above formula, 0.90. ltoreq. a.ltoreq.1.8, 0. ltoreq. b.ltoreq.0.5, 0. ltoreq. c.ltoreq.0.05, and 0< alpha < 2); LiaNi1-b-cmNbRcD alpha (in the above formula, 0.90. ltoreq. a.ltoreq.1.8, 0. ltoreq. b.ltoreq.0.5, 0. ltoreq. c.ltoreq.0.05, and 0< alpha.ltoreq.2); LiaNi1-b-cmNbRcO 2-alpha Z alpha (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and alpha is more than 0 and less than 2); LiaNi1-b-cmNbRcO 2-alpha Z2 (in the above formula, a is 0.90. ltoreq. a.ltoreq.1.8, b is 0. ltoreq. b.ltoreq.0.5, c is 0. ltoreq. c.ltoreq.0.05, and 0< alpha < 2); LiaNibEcGdO2 (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, b is more than or equal to 0 and less than or equal to 0.9, c is more than or equal to 0 and less than or equal to 0.5, and d is more than or equal to 0.001 and less than or equal to 0.1); LiaNibCoMndGeO 2 (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, b is more than or equal to 0 and less than or equal to 0.9, c is more than or equal to 0 and less than or equal to 0.5, d is more than or equal to 0 and less than or equal to 0.5, and e is more than or equal to 0.001 and less than or equal to 0.1); LiaNiGbO2 (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, and b is more than or equal to 0.001 and less than or equal to 0.1); LiaCoGbO2 (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, and b is more than or equal to 0.001 and less than or equal to 0.1); LiaMnGbO2 (in the formula, a is more than or equal to 0.90 and less than or equal to 1.8, and b is more than or equal to 0.001 and less than or equal to 0.1); LiaMn2GbO4 (in the above formula, 0.90. ltoreq. a.ltoreq.1.8 and 0.001. ltoreq. b.ltoreq.0.1); QO 2; QS 2; LiQS 2; V2O 5; LiV2O 5; lito 2; LiNiVO 4; li (3-f) J2(PO4)3 (f is more than or equal to 0 and less than or equal to 2); li (3-f) Fe2(PO4)3 (f is more than or equal to 0 and less than or equal to 2); and LiFePO 4.

In the above chemical formula, A is Ni, Co, Mn or a combination thereof; r is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, rare earth elements or the combination thereof; d is O, F, S, P or a combination thereof; e is Co, Mn or a combination thereof; z is F, S, P or a combination thereof; g is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V or their combination; q is Ti, Mo, Mn or their combination; t is Cr, V, Fe, Sc, Y or their combination; j is V, Cr, Mn, Co, Ni, Cu or their combination.

Of course, an anode active material having a coating layer on the surface of this compound may also be used, or alternatively, the compound may also be used by mixing the compound with a compound having a coating layer. The coating layer, as a coating element compound, may include: an oxide, hydroxide, oxyhydroxide, oxycarbonate, or oxycarbonate of a coating element. The compounds forming these coating layers may be amorphous or crystalline. The coating element contained in the coating layer may use Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or a mixture thereof. As long as the compound can be coated with these elements by a method that does not adversely affect the physical properties of the positive electrode active material, any coating method such as spray coating or dipping may be used in the coating layer forming step, and the detailed description thereof will be omitted since it is well understood by those skilled in the art.

Although not limited, the positive active material may include 20 to 99% by weight, and more preferably, may include 30 to 95% by weight of the total weight of the composition. The average particle size is 0.001 to 50 μm, and more preferably 0.01 to 20 μm, but is not limited thereto.

The binder serves to better bind the positive electrode active material particles to each other and also to fix the positive electrode active material to the current collector. Any one or more of polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, a polymer containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, and the like, or a mixture thereof may be used as a typical example, but not limited thereto. Although not limited thereto, the content of the binder is 0.1 to 20 wt% of the total weight, and more preferably 1 to 10 wt% may be used. The content thereof is a content sufficient to function as a binder within the range, but the content is not limited thereto.

The solvent may be one or a mixture of two or more selected from N-methylpyrrolidone, acetone, water, and the like, but is not limited thereto as long as it is commonly used in the art. The content of the solvent is not limited, and any content may be used without limitation as long as it can be applied to the positive electrode current collector in a slurry state.

Also, the positive active material composition may further include a conductive material.

The conductive material is used to impart conductivity to the electrode, and any electronically conductive material that does not cause chemical changes in the battery to be configured may be used without limitation. Specifically, for example, it is possible to use a conductive material including carbon-based substances such as natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, carbon nanotubes, and carbon fibers; metal powders such as copper, nickel, aluminum, and silver, or metal materials such as metal fibers; conductive polymers such as polyphenylene derivatives; or mixtures thereof. These may be used alone or in combination of two or more of them.

The content of the conductive material is 0.1 to 20 wt%, specifically 0.5 to 10 wt%, more specifically 1 to 5 wt% of the positive electrode active material composition, but is not limited thereto. The average particle size of the conductive material is 0.001 to 1000 μm, more specifically 0.01 to 100 μm, but is not limited thereto.

According to an embodiment of the present invention, the positive electrode active material layer may include pores, and a porosity (por porosity) may be 5 to 30 vol%, and more particularly, may be 10 to 20 vol%, but is not limited thereto. When the porosity is within the above range, there is a problem in that when a liquid electrolyte or a gel polyelectrolyte is injected, impregnation into the central portion of the battery is difficult due to low porosity, but according to an embodiment of the present invention, the electrolyte layer may be formed by coating the gel polyelectrolyte, whereby a uniformly impregnated electrolyte layer may be formed despite low porosity.

According to an embodiment of the present invention, the positive electrode-electrolyte assembly is a structure in which the liquid electrolyte or the gel polymer electrolyte is laminated or impregnated in the positive electrode to be integrated. The impregnation means that the integration is achieved by partial or complete infiltration.

In the cathode-electrolyte combination, when the first electrolyte is a gel polyelectrolyte, the thickness of the gel polyelectrolyte layer may be 0.01 μm to 500 μm. Specifically, it may be 0.01 to 100 μm, but is not limited thereto. When the thickness of the gel polyelectrolyte layer satisfies the range, the performance of the electrochemical device is improved and the simplicity of the manufacturing process is also facilitated.

(2) Negative electrode-electrolyte combination

According to an embodiment of the present invention, the negative electrode may be composed of various forms, and specifically, for example, may be selected from i) an electrode formed only of a current collector, and ii) an electrode in which an active material layer including a negative electrode active material and a binder is coated on a current collector.

The negative electrode current collector may be in the form of a thin film or Mesh (Mesh), and the material thereof may be made of metal, lithium aluminum alloy, other lithium metal alloys, or the like, or polymer. The negative electrode of the present invention may be formed by using the thin film or mesh-shaped current collector as it is, or may be formed by laminating a thin film or mesh-shaped current collector on a conductive substrate to be integrated.

The current collector may be used without limitation as long as it is a substrate having excellent conductivity used in the art. Specifically, for example, it contains any one selected from a conductive metal, a conductive metal oxide, and the like. The current collector may be formed entirely of a conductive material, or may be formed by coating one or both surfaces of an insulating substrate with a conductive metal, a conductive metal oxide, a conductive polymer, or the like. Also, the current collector may be composed of a flexible substrate, and thus may be easily bent, so that a flexible electronic device may be provided. And, it may be made of a material having a restoring force capable of restoring its original form after being bent. More specifically, for example, the current collector may be composed of a polymer substrate coated with aluminum, stainless steel, copper, nickel, iron, lithium, cobalt, titanium, nickel foam, copper foam, and a conductive metal, or the like, but is not limited thereto.

According to the aspect of ii) of the negative electrode of the present invention, the negative electrode in which the active material layer is coated can be realized by coating the negative electrode active material composition containing the negative electrode active material and the binder on the current collector. The current collector may be the same as the current collector described above, and the negative electrode active material composition may be directly applied to a current collector such as a metal thin film and dried to produce a negative electrode sheet having a negative electrode active material layer formed thereon.

Alternatively, the negative electrode active material composition may be cast on a separate support, and then a film obtained by peeling the negative electrode active material composition from the support may be laminated on the current collector, thereby preparing a negative electrode having a negative electrode active material layer formed thereon. The thickness of the negative electrode active material layer is not limited, but it may be 0.01 to 500 μm, more specifically, 0.1 to 200 μm, but is not limited thereto.

The negative electrode active material composition is not limited, but may include a negative electrode active material, a binder, and a solvent, and may also be a composition including a conductive material.

As the negative electrode active material, any one commonly used in the art may be used without limitation. Specifically, for example, a lithium primary battery or a secondary battery may use a compound capable of reversibly intercalating and deintercalating lithium (lithiated intercalation compound). The negative electrode active material of the present invention may be in the form of powder.

More specifically, for example, it may be a mixture of one or two or more of a metal alloyable with lithium, a transition metal oxide, a non-transition metal oxide, a carbon-based material, and the like.

Examples of the metal alloyable with lithium include, but are not limited to, Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn.

The transition metal oxide may be lithium titanium oxide, vanadium oxide, lithium vanadium oxide, or the like, and it may be either alone or a mixture of two or more of them.

As the non-transition metal oxide, Si and SiO are listed_x(0<x<2) Si-C composite, Si-Q alloy (wherein Q is alkali metal, alkaline earth metal, group 13-16 element, transition metal, rare earth element or combination thereof, and is not Si), Sn, SnO₂Sn-C composite, Sn-R (wherein R is alkali metal, alkaline earth metal, group 13 to group 16 element, transition metal, rare earth element or combination thereof, and is not Sn), and the like. The specific element of Q and R may be one or a mixture of two or more selected from Mg, Ca, Sr, Ba, Ra, Sc, Y, Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg, Tc, Re, Bh, Fe, Pb, Ru, Os, Hs, Rh, Ir, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, Sn, In, Ti, Ge, P, As, Sb, Bi, S, Se, Te, Po and the like.

The carbon-based material may use one or a mixture of two or more selected from crystalline carbon, amorphous carbon, and a combination thereof. As examples of the crystalline carbon, graphite such as amorphous, plate-like, sheet-like, spherical or fibrous natural graphite or artificial graphite can be used, and as examples of the amorphous carbon, soft carbon, hard carbon, mesophase pitch carbide, calcined coke and the like can be used, but the amorphous carbon is not limited thereto.

Although there is no particular limitation on the content of the negative active material, the content of the negative active material may be 1 to 90 wt% of the total weight of the composition, and more preferably may include 5 to 80 wt%. The average particle size is 0.001 to 20 μm, and more preferably 0.01 to 15 μm, but is not limited thereto.

The binder serves to better bind the anode active material particles to each other and also to fix the anode active material to the current collector. Any one commonly used in the art may be used without limitation, and as typical examples, polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinyl pyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene-butadiene rubber, epoxy resin, nylon, and the like may be used, but not limited thereto.

The solvent may be one or a mixture of two or more selected from N-methylpyrrolidone, acetone, water, and the like, but is not limited thereto as long as it is commonly used in the art.

Also, the negative active material composition may further include a conductive material.

The conductive material is used for imparting conductivity to the electrode, and any electronically conductive material that does not cause chemical changes in the battery to be constructed can be used without limitation, and examples thereof include conductive materials such as natural graphite, artificial graphite, carbon black, acetylene black, ketjen black, and carbon-based substances such as carbon fibers; metal powders such as copper, nickel, aluminum, and silver, or metal materials such as metal fibers; conductive polymers such as polyphenylene derivative (polyphenylene derivative); or mixtures thereof.

The content of the conductive material is 1 to 90 wt% of the negative active material composition, and more specifically, may include 5 to 80 wt%, but is not limited thereto.

The average particle size of the conductive material is 0.001 to 100 μm, more specifically 0.01 to 80 μm, but is not limited thereto.

According to an embodiment of the present invention, the anode active material layer may include pores, and a porosity (por porosity) may be 10 to 35 vol%, and more particularly, may be 15 to 25 vol%, but is not limited thereto. When the porosity is within the above range, there is a problem in that when a liquid electrolyte or a gel polyelectrolyte is injected, impregnation into the central portion of the battery is difficult due to low porosity, but according to an embodiment of the present invention, the electrolyte layer may be formed by coating the gel polyelectrolyte, whereby a uniformly impregnated electrolyte layer may be formed despite low porosity.

According to an embodiment of the present invention, the negative electrode-electrolyte combined body is a structure in which the liquid electrolyte or the gel polymer electrolyte is laminated or impregnated in the negative electrode to be integrated. The impregnation means that the integration is achieved by partial or complete infiltration.

In the negative electrode-electrolyte combination, when the second electrolyte is a gel polyelectrolyte, the thickness of the gel polyelectrolyte layer may be 0.01 μm to 500 μm. Specifically, it may be 0.01 to 100. mu.m, more preferably 0.01 to 50 μm, but is not limited thereto. When the thickness of the gel polyelectrolyte layer satisfies the range, the performance of the electrochemical device is improved and the simplicity of the manufacturing process is also facilitated.

(3) Separator-electrolyte combination

According to an embodiment of the present invention, the separator may be used without limitation as long as it is a separator commonly used in the art. For example, it may be woven fabric, nonwoven fabric, porous film, or the like. Further, it may be a multilayer film obtained by laminating one or more layers. The material of the separator is not limited, but specifically, for example, it may be composed of one or a mixture of two or more selected from the group consisting of polyethylene, polypropylene, polybutene, polypentene, polymethylpentene, polyethylene terephthalate, polybutylene terephthalate, polyacetal, polyamide, polycarbonate, polyimide, polyethersulfone, polyphenylene ether, polyphenylene sulfide, polyethylene naphthalate, a copolymer thereof, and the like. Also, the thickness thereof is not limited, and may be in a range commonly used in the art, i.e., 1 to 1000 μm, and more specifically, may be 10 to 800 μm, without being limited thereto.

According to an embodiment of the present invention, the separator-electrolyte combination is a structure in which the liquid electrolyte or the gel polyelectrolyte is laminated or impregnated in a separator to be integrated. The impregnation means that the integration is achieved by partial or complete infiltration.

In the separator-electrolyte combination, in the case where the third electrolyte is a gel polyelectrolyte, the thickness of the gel polyelectrolyte layer may be 0.01 μm to 500 μm. More specifically, it may be 0.01 μm to 100 μm, but is not limited thereto. When the thickness of the gel polyelectrolyte layer satisfies the range, the performance of the electrochemical device is improved and the simplicity of the manufacturing process is also facilitated.

(4) Electrochemical device

According to an embodiment of the present invention, the electrochemical device may be a primary battery or a secondary battery capable of performing an electrochemical reaction.

More specifically, the electrochemical device may be a lithium primary battery, a lithium secondary battery, a lithium sulfur battery, a lithium air battery, a sodium battery, an aluminum battery, a magnesium battery, a calcium battery, a sodium air battery, an aluminum air battery, a magnesium air battery, a calcium air battery, a supercapacitor, a dye-sensitized solar cell, a fuel cell, a lead storage battery, a nickel cadmium battery, a nickel hydrogen storage battery, an alkaline battery, and the like, but is not limited thereto.

(5) Method for manufacturing electrochemical device

Hereinafter, a method of manufacturing an electrochemical device according to an embodiment of the present invention will be described in further detail.

As described above, the electrochemical device of the present invention may be manufactured in various forms, and a manufacturing method of several forms thereof will be specifically described below, but it is apparent that this is only an example for specific description, and the present invention is not limited thereto.

A first embodiment of the method of manufacturing an electrochemical device of the present invention comprises: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, a b) step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, a separator, and a negative electrode, and a c) step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material, wherein the first electrolyte and the liquid electrolyte have different ionic conductivities.

A second embodiment of the method of manufacturing an electrochemical device of the present invention comprises: a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, b) a step of manufacturing an electrode assembly by laminating a positive electrode, a separator, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material, wherein the second electrolyte and the liquid electrolyte have different ionic conductivities.

The third embodiment of the method for manufacturing the electrochemical device of the present invention includes: a) a step of manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, b) a step of manufacturing an electrode assembly by laminating a positive electrode, the separator-electrolyte combination, and a negative electrode, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material, wherein ionic conductivities of the third electrolyte and the liquid electrolyte are different.

A fourth embodiment of the method of manufacturing an electrochemical device of the present invention comprises: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, b) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, a separator, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material, wherein at least one selected from the first electrolyte, the second electrolyte, and the liquid electrolyte has different ion conductivities.

A fifth embodiment of the method of manufacturing an electrochemical device of the present invention comprises: a) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, and manufacturing a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, b) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination, and a negative electrode, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material, wherein at least one selected from the first electrolyte, the third electrolyte, and the liquid electrolyte has different ion conductivities.

A sixth embodiment of the method of manufacturing an electrochemical device of the present invention comprises: a) a step of manufacturing a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, and a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, b) a step of manufacturing an electrode assembly by laminating a positive electrode, the separator-electrolyte combination, and the negative electrode-electrolyte combination, and c) a step of injecting a liquid electrolyte after sealing the electrode assembly with a packaging material, wherein at least one selected from the second electrolyte, the third electrolyte, and the liquid electrolyte has different ion conductivities.

In the first to sixth embodiments, at least one selected from the group consisting of the first electrolyte, the second electrolyte, and the liquid electrolyte may be different in at least one selected from the group consisting of a type of solvent, a type of a dissociable salt, and a concentration of the dissociable salt.

In the first to sixth embodiments, the b) step may be selected from: b-1) laminating the positive electrode or the positive electrode-electrolyte combination, the separator or the separator-electrolyte combination, and the negative electrode or the negative electrode-electrolyte combination, and then cutting the laminated positive electrode or the positive electrode-electrolyte combination into a specific shape to manufacture an electrode assembly; or b-2) a step of manufacturing an electrode assembly by laminating after cutting the positive electrode or the positive electrode-electrolyte combination, the separator or the separator-electrolyte combination, and the negative electrode or the negative electrode-electrolyte combination into specific shapes, respectively.

A seventh embodiment of the method of manufacturing an electrochemical device of the present invention comprises: i) a step of manufacturing a positive electrode-electrolyte combination including a first electrolyte by coating and curing a first gel polyelectrolyte composition on a positive electrode, a negative electrode-electrolyte combination including a second electrolyte by coating and curing a second gel polyelectrolyte composition on a negative electrode, and a separator-electrolyte combination including a third electrolyte by coating and curing a third gel polyelectrolyte composition on a separator, and ii) a step of manufacturing an electrode assembly by laminating the positive electrode-electrolyte combination, the separator-electrolyte combination, and the negative electrode-electrolyte combination, at least one selected from the first electrolyte, the second electrolyte, and the third electrolyte having different ion conductivities.

In the seventh embodiment, at least one selected from the first gel polymer electrolyte composition, the second gel polymer electrolyte composition, and the third gel polymer electrolyte composition may be different in at least one selected from the group consisting of the kind of a solvent, the kind of a dissociable salt, and the concentration of the dissociable salt. Also, the kind or concentration of the monomer may be different, which is not excluded.

And, in a seventh embodiment, said ii) step may be selected from: ii-1) laminating the positive electrode-electrolyte assembly, the separator-electrolyte assembly and the negative electrode-electrolyte assembly, and cutting the laminated positive electrode-electrolyte assembly, separator-electrolyte assembly and negative electrode-electrolyte assembly into specific shapes; or ii-2) a step of cutting the positive electrode-electrolyte assembly, the separator-electrolyte assembly, and the negative electrode-electrolyte assembly into specific shapes and laminating the cut products.

Also, in the fifth embodiment, after the step of ii), a step of iii) sealing the electrode assembly with a packing material may be further included.

In one embodiment of the production method of the present invention, the gel polymer electrolyte can be coated by a coating method such as bar coating, spin coating, slot coating, dip coating, and spray coating, and a printing method such as inkjet printing, gravure offset printing, aerosol printing, stencil printing, and screen printing, and thus the gel polymer electrolyte can be continuously produced.

More specifically, the gel polyelectrolyte polymerization composition is coated and crosslinked by ultraviolet irradiation or application of heat, so that the liquid electrolyte is uniformly distributed in the network structure of the crosslinked polymer matrix, and an evaporation process of the solvent may be unnecessary.

Also, since the gel polyelectrolyte can be formed by a coating method, it can be formed by coating a separate electrolyte suitable for the characteristics of each electrode. Further, since the gel polymer electrolyte can be formed by a coating method, the electrolyte can be uniformly formed on the electrode and the separator as compared with an injection method. Further, since the gel polyelectrolyte has a crosslinked structure, the degree of miscibility of components in the gel polyelectrolyte with the liquid electrolyte is low even when used for a long period of time.

According to an embodiment of the present invention, the liquid electrolyte may be injected after being sealed with a packaging material.

The liquid electrolyte and the gel polymer electrolyte polymerization composition are the same as those described above, and therefore, the repetitive description thereof will be omitted.

Hereinafter, the present invention will be described in more detail based on examples and comparative examples. However, the following examples and comparative examples are merely one example for explaining the present invention in more detail, and the present invention is not limited to the following examples and comparative examples.

1) Ionic conductivity

The ionic conductivity can be confirmed by a formula.

[ equation 1]

IC₁＝(τ_cathode ²×IC_cathode)/P_cathode

[ formula 2]

IC₂＝(τ_anode ²×IC_anode)/P_anode

[ formula 3]

IC₃＝(τ_separator ²×IC_separator)/P_separator

At this time, IC₁、IC₂、IC₃Ion conductivities of the first electrolyte, the second electrolyte and the third electrolyte, respectively, IC_cathode、IC_anode、IC_separatorThe ion conductivities, τ, of the positive electrode-electrolyte combination, the negative electrode-electrolyte combination and the separator-electrolyte combination, respectively_cathode、τ_anode、τ_separatorThe positive electrode, the negative electrode, and the separator respectively have a curvature (Tortuity), P_cathode、P_anode、P_separatorThe porosity of the positive electrode, the negative electrode, and the separator.

To calculate the ionic conductivity of the electrolyte, the porosity (vol%) of the test piece may be measured using a mercury vapor pressure porosimeter for each of the positive electrode, the negative electrode, and the separator. A standard electrolyte having a known ionic conductivity was used (in this patent, 1 mol of LiPF dissolved in a solvent in which 50 vol% of ethylene carbonate and 50 vol% of ethyl methyl carbonate were mixed was used as the standard electrolyte₆The liquid electrolyte) of the positive electrode-electrolyte assembly, the negative electrode-electrolyte assembly, and the separator-electrolyte assembly, and the curvatures of the positive electrode, the negative electrode, and the separator can be calculated from the above formulas.

After the positive electrode-electrolyte assembly, the negative electrode-electrolyte assembly and the separator-electrolyte assembly were cut into a circular shape having a diameter of 18mm and button batteries (2032) were manufactured, respectively, the ionic conductivity was measured by an ac impedance measurement method according to temperature. Regarding the measurement of the ionic conductivity, the measurement was performed in a frequency band of 1MHz to 0.01Hz using a VMP3 measuring device.

In the case of an electrochemical device comprising any one of the electrolytes, the seal is removed, the positive electrode-electrolyte combination, the negative electrode-electrolyte combination and the separator-electrolyte combination are separated, each combination is added with a dimethyl carbonate solvent and stored for 24 hours, then an acetone solvent is added and stored for 24 hours, then a dimethyl carbonate solvent is added and stored for 24 hours, thereby removing the electrolyte in each combination, and then dried under a vacuum atmosphere for 24 hours (at this time, the positive electrode and the negative electrode from which the electrolyte is removed are dried at 130 ℃, and the separator is dried at 60 ℃). The curvatures of the positive electrode, the negative electrode, and the separator from which the electrolyte is removed are calculated using the porosity and the standard electrolyte by the above-mentioned method, the ion conductivities of the positive electrode-electrolyte combination, the negative electrode-electrolyte combination, and the separator-electrolyte combination in the state before the electrolyte is removed are measured, and the ion conductivities of the first electrolyte, the second electrolyte, and the third electrolyte may be calculated by the above formula.

Next, nyquist graphs for measuring the ion conductivities of the cathode-electrolyte combination, the anode-electrolyte combination, and the separator-electrolyte combination will be described in detail. The positive electrode-electrolyte assembly and the negative electrode-electrolyte assembly are composite conductors, which are both electron conductors and ion conductors, and the nyquist diagram for this shows a substantially semicircular shape. At this time, the semicircle is divided into a high frequency region resistor (R)₁) And low frequency region resistance (R)₂) The resistance to ion conduction can be calculated by the following equation.

[ formula 4]

R_ion＝R₂-R₁

The separator-electrolyte combination is an ion conductor and shows a shape that rises substantially vertically in the nyquist diagram, and the resistance value on the horizontal axis indicates resistance to ion conduction. The ion conductivities of the positive electrode-electrolyte assembly, the negative electrode-electrolyte assembly, and the separator-electrolyte assembly were such that the resistance values of the ion conductivities obtained above were calculated by the following formulas.

[ formula 5]

IC＝L/(R_ion×A)

In this case, L is the thickness of the test piece (excluding the thickness of the positive and negative electrode collectors and the thickness of the separator), and a is the area of the test piece.

2) Slope of arrhenius plot

The ion conductivity data for each temperature obtained above was plotted in a graph in such a manner that the reciprocal 1/T of the temperature T (K) and the logarithm ln (IC) of the ion conductivity are shown on the horizontal axis and the vertical axis, respectively, with respect to the slope of the Arrhenius plot, thereby obtaining the slope of the straight line at a temperature of 20 to 80 ℃.

3) Viscosity of the oil

Measurements were performed using a Brookfield viscometer (Dv2TRV-cone & plate, CPA-52Z) at 25 ℃ temperature conditions.

4) Battery performance evaluation

For lithium batteries, the voltage range is 0.1C (═ 0.3 mA/cm) at 3.0-4.2V under normal temperature (25 deg.C) conditions²) The initial charge/discharge capacity was observed, and 0.2C (═ 0.6 mA/cm) was observed²) Life characteristics of the lithium battery according to the number of charge/discharge times under the current.

The initial discharge capacity was the first cycle discharge capacity (mAh/cm)²). The initial charge-discharge efficiency is the ratio of the charge capacity to the discharge capacity in the first cycle. The capacity retention rate with respect to the life characteristics was calculated by the following formula.

Capacity retention rate (%) [ 200 th cycle discharge capacity/first cycle discharge capacity ] × 100

5) Porosity of the alloy

The porosity (vol%) of the test piece was measured for the positive electrode and the negative electrode using a Mercury intrusion porosity measuring Instrument (Mercury intrusion porosity try, equipment name: AutoPore IV 9500, equipment manufacturer: mcmimeric instruments Corp.). In order to eliminate the influence of pores formed by laminating the samples, the porosity of the electrode was calculated under the condition of a pressure range of 30psia to 60000 psia.

6) Infrared spectroscopy

The positive electrode, the negative electrode, and the separator were separated from the electrode assembly in a state where the initial formation process was completed by applying the charge and discharge current, and fourier transform infrared spectroscopy (equipment name: 670-IR, equipment manufacturer: Varian) was performed for each. The absorption spectrum obtained by spectroscopic analysis of the reflected light when the infrared ray was irradiated confirmed to be the peak intensity of the substance characteristic which can be discriminated from the kind of the solvent, the kind of the salt and the concentration of the salt.

7) X-ray photoelectron analysis

The positive electrode, the negative electrode, and the separator were separated from the electrode assembly in a state where the initial formation process was completed by applying charge and discharge currents, and each was subjected to X-ray Photoelectron spectroscopy (X-ray Photoelectron spectroscopy py, equipment name: K-Alpha, equipment manufacturer: seemer Fisher (Thermo Fisher)). The energy of photoelectrons escaping from the sample upon irradiation with X-rays confirmed that the presence or absence of elements contained in different solvents and salts and the state of chemical bonds can be discriminated. .

8) Inductively coupled plasma mass spectrometry

The positive electrode, the negative electrode, and the separator were separated from the electrode assembly in the state in which the initial formation process was completed by applying the charge and discharge current, and each was subjected to Inductively Coupled Plasma Mass spectrometry (Inductively Coupled Plasma Mass spectrometer, equipment name: ELAN DRC-II, equipment manufacturer: Perkin Elmer). It was confirmed that the type of solvent, the type of salt, and the concentration of salt can be distinguished and determined by ionizing the salt contained in the sample and separating the ions using a mass spectrometer.

9) Nuclear magnetic resonance spectroscopy

The positive electrode, the negative electrode, and the separator were separated from the electrode assembly in a state where the initial formation process was completed by applying the charge and discharge current, and each was subjected to two-dimensional Nuclear Magnetic resonance Spectroscopy (Nuclear Magnetic resonance Spectroscopy, equipment name: AVANCE III HD, equipment manufacturer: Bruker (Bruker)). Information on the chemical environment around the nuclei and spin coupling with adjacent atoms is obtained by utilizing nuclear magnetic resonance phenomenon of the nuclei that occurs when a magnetic field is applied to the performance enhancing agent contained in the sample, and it is confirmed that the type of the solvent, the type of the salt, and the concentration of the salt can be distinguished and judged differently.

10) Time-of-flight secondary ion mass spectrometry

The positive electrode, the negative electrode, and the separator were separated from the electrode assembly in the state in which the initial formation process was completed by applying the charge and discharge current, and Time-of-flight secondary ion Mass Spectrometry (Time-of-flight secondary ion Mass Spectrometry, equipment name: TOF-SIMS 5, equipment manufacturer: ion of (iontoff)) was performed for each. Mass spectrometry of secondary ions generated in the sample confirmed that different solvent types, salt types, and salt concentrations could be distinguished.

[ example 1]

1) Manufacture of positive electrode-electrolyte combination

95% by weight of a lithium cobalt composite oxide (LiCoO) having an average particle diameter of 5 μm₂) (as a positive electrode active material), 2 wt% of Super-P (as a conductive material) having an average particle diameter of 40nm, and 3 wt% of polyvinylidene fluoride (as a binder) were added to N-methyl-2-pyrrolidone as an organic solvent until the solid content was 50 wt%, thereby preparing a positive electrode active material composition (positive electrode mixture slurry).

The positive electrode active material composition was applied to an aluminum thin film having a thickness of 20 μm using a doctor blade, dried at a temperature of 120 ℃, and then rolled with a roll press to prepare a positive electrode coated with an active material layer having a thickness of 40 μm (porosity of 15 vol%).

The first electrolyte composition was coated on the active material layer of the prepared positive electrode using a doctor blade and at 2000mW/cm²Ultraviolet rays were irradiated for 20 seconds to perform crosslinking, thereby preparing a 41 μm thick cathode-electrolyte combination formed with a first gel polyelectrolyte layer.

The first electrolyte composition was a mixture of 5 wt% of ethoxylated trimethylolpropane triacrylate, 0.1 wt% of hydroxymethylphenyl acetone (as a photoinitiator), 94.9 wt% of a liquid electrolyte. The liquid electrolyte is used as a liquid electrolyte with excellent electrochemical properties1 mol of LiPF is dissolved in propylene carbonate (propylene carbonate) which is a cyclic carbonate organic solvent having chemical oxidation stability₆The liquid electrolyte of (1). The viscosity of the first gel polyelectrolyte composition at 25 ℃ is 10 cps.

2) Production of negative electrode-electrolyte combination

A negative electrode active material composition (negative electrode mixture slurry) was prepared by adding 96 wt% of natural graphite powder (as a negative electrode active material), 2 wt% of carbon black having an average particle diameter of 40nm (as a conductive material), 1 wt% of styrene-butadiene rubber (as a binder), and 1 wt% of carboxymethyl cellulose to water. The negative electrode active material composition was applied to a copper thin film having a thickness of 20 μm using a doctor blade, dried at a temperature of 120 ℃, and then rolled with a roll press to prepare a negative electrode coated with an active material layer having a thickness of 40 μm (porosity of 20 vol%).

The second electrolyte composition was coated on the active material layer of the prepared negative electrode using a doctor blade to manufacture a negative electrode-electrolyte combination.

The second electrolyte composition used a liquid electrolyte of dimethoxyethane (dimethoxyethane) solvent with 4 moles of LiFSI dissolved therein. The viscosity of the second electrolyte was 60cps at a temperature of 25 ℃.

3) Production of separator-electrolyte combination

A polyolefin microporous membrane (Celgard 3501, Celgard) having a thickness of 25 μm was used as the separator.

The third electrolyte composition was coated on the prepared separator using a doctor blade to manufacture a separator-electrolyte combination.

The third electrolyte composition uses 1 mole of LiPF dissolved in propylene carbonate (propylene carbonate)₆The liquid electrolyte of (1). The viscosity of the third electrolyte was 8.4cps at a temperature of 25 ℃.

4) Production of lithium ion secondary battery

After the positive electrode-electrolyte assembly, the separator-electrolyte assembly, and the negative electrode-electrolyte assembly were laminated, a battery (button battery) was manufactured by punching.

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

[ example 2]

The first and second electrolyte compositions are the same as described in example 1. 5 wt% of ethoxylated trimethylolpropane triacrylate, 0.1 wt% of hydroxymethylphenyl propanone (as a photoinitiator) were mixed, and 1 mol of LiPF was dissolved in a propylene carbonate solvent₆94.9 wt.% of a liquid electrolyte the third electrolyte composition was coated using a doctor blade and at 2000mW/cm^-2A battery (button cell) was produced in the same manner as in example 1, except that ultraviolet rays were irradiated for 20 seconds to perform crosslinking, thereby preparing a separator-electrolyte combination having a thickness of 30 μm, on which a third gel polyelectrolyte layer was formed.

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

[ example 3]

The first and second electrolyte compositions are the same as described in example 1. 5 wt% of ethoxylated trimethylolpropane triacrylate and 0.1 wt% of hydroxymethylphenyl acetone (as a photoinitiator) were mixed, and 4 moles of LiPF were dissolved in a propylene carbonate solvent₆94.9 wt.% of a liquid electrolyte on a separator using a doctor blade and at 2000mW/cm^-2A battery (button cell) was produced in the same manner as in example 1, except that ultraviolet rays were irradiated for 20 seconds to perform crosslinking, thereby preparing a separator-electrolyte combination having a thickness of 30 μm, on which a third gel polyelectrolyte layer was formed.

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

[ example 4]

The first electrolyte composition was the same as described in example 1. A second electrolyte composition mixing 5 wt% of ethoxylated trimethylolpropane triacrylate, 0.1 wt% of hydroxymethylphenylacetone (as a photoinitiator), and a liquid electrolyte having 4 moles of 94.9 wt% LiFSI dissolved in dimethoxyethane solvent was coated on the active material layer of the negative electrode using a doctor blade and applied at 2000mW/cm^-2Ultraviolet rays were irradiated for 20 seconds to perform crosslinking, thereby preparing a negative electrode-electrolyte combination having a thickness of 41 μm, on which a second gel polyelectrolyte layer was formed. 5 wt% of ethoxylated trimethylolpropane triacrylate and 0.1 wt% of hydroxymethylphenyl acetone (as a photoinitiator) were mixed, and 1 mol of LiPF was dissolved in a propylene carbonate solvent₆94.9 wt% liquid electrolyte on separator using a doctor blade and at 2000mW/cm^-2Ultraviolet rays were irradiated for 20 seconds to perform crosslinking, thereby preparing a separator-electrolyte combination having a thickness of 30 μm, on which a third gel polyelectrolyte layer was formed, and a battery (button cell) was manufactured in the same manner as in example 1, except for the negative electrode-electrolyte combination and the separator-electrolyte combination.

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

[ example 5]

The first electrolyte composition was the same as described in example 1. 5% by weight of ethoxylated trimethylolpropane triacrylate, 0.1% by weight of hydroxymethylphenylacetone (as photoinitiator), 94.9% by weight of a liquid electrolyte having 4 moles of LiFSI dissolved in dimethoxyethane solvent were mixed as the second electrolyte composition, and 5% by weight of ethoxylated trimethylolpropane triacrylate, 0.1% by weight of hydroxymethylphenylacetone (as photoinitiator), dimethoxyethane was mixedA 94.9 wt% liquid electrolyte in which 4 moles of LiFSI was dissolved in a solvent was used as a third electrolyte composition, and a battery (button battery) was manufactured in the same manner as in example 1 except for the second electrolyte composition and the third electrolyte composition. A second electrolyte composition, in which 5 wt% of ethoxylated trimethylolpropane triacrylate, 0.1 wt% of hydroxymethylphenylacetone (as a photoinitiator), and 94.9 wt% of a liquid electrolyte having 4 moles of LiFSI dissolved in dimethoxyethane solvent were mixed, was coated on the active material layer of the negative electrode using a doctor blade, and the coating was performed at 2000mW/cm^-2Ultraviolet rays were irradiated for 20 seconds to perform crosslinking, thereby preparing a negative electrode-electrolyte combination having a thickness of 41 μm, in which a second gel polyelectrolyte layer was formed, and a third electrolyte composition, in which 5 wt% of ethoxylated trimethylolpropane triacrylate, 0.1 wt% of hydroxymethylphenyl acetone (as a photoinitiator), and 94.9 wt% of a liquid electrolyte having 4 moles of LiFSI dissolved in a propylene carbonate solvent were mixed, was coated on a separator using a doctor blade, and at 2000mW/cm^-2A separator-electrolyte combination having a thickness of 30 μm, on which a third gel polyelectrolyte layer was formed, was prepared by irradiating ultraviolet rays for 20 seconds to perform crosslinking, and a battery (button cell) was manufactured in the same manner as in example 1, except for the negative electrode-electrolyte combination and the separator-electrolyte combination.

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

Comparative example 1

The same positive electrode, negative electrode and separator as in example 1 were used, and the same electrolyte composition was used for all of the positive electrode, negative electrode and separator.

The gel polyelectrolyte is prepared by mixing 5 wt% of ethoxylated trimethylolpropane triacrylate, 0.1 wt% of hydroxymethyl phenyl acetone (as photoinitiator) and 1 mol of LiPF dissolved in propylene carbonate solvent₆94.9 wt% of a liquid electrolyte,the gel polyelectrolyte was coated on the positive electrode active material layer, the negative electrode active material layer and the separator with a doctor blade at 2000mW/cm^-2A positive electrode-electrolyte combination having a thickness of 41 μm, a negative electrode-electrolyte combination having a thickness of 41 μm, and a separator-electrolyte combination having a thickness of 30 μm were prepared by irradiating ultraviolet rays for 20 seconds to perform crosslinking, and a battery (button cell) was manufactured in the same manner as in example 1, except for the positive electrode-electrolyte combination, the negative electrode-electrolyte combination, and the separator-electrolyte combination.

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

Comparative example 2

The same positive electrode, negative electrode and separator as in example 1 were used, and the same electrolyte composition was used for all of the positive electrode, negative electrode and separator.

The gel polymer electrolyte was a composition in which 5 wt% of ethoxylated trimethylolpropane triacrylate, 0.1 wt% of hydroxymethylphenyl acetone (as a photoinitiator), and 94.9 wt% of a liquid electrolyte in which 4 moles of LiFSI was dissolved in dimethoxyethane solvent were mixed, and the gel polymer electrolyte was coated on the positive electrode active material layer, the negative electrode active material layer, and the separator using a doctor blade, respectively, at 2000mW/cm^-2A positive electrode-electrolyte combination having a thickness of 41 μm, a negative electrode-electrolyte combination having a thickness of 41 μm, and a separator-electrolyte combination having a thickness of 30 μm were prepared by irradiating ultraviolet rays for 20 seconds to perform crosslinking, and a battery (button cell) was manufactured in the same manner as in example 1, except for the positive electrode-electrolyte combination, the negative electrode-electrolyte combination, and the separator-electrolyte combination.

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

Comparative example 3

A battery (button cell) was produced by using the same positive electrode, negative electrode and separator as in example 1 and injecting the same liquid electrolyte into the positive electrode, negative electrode and separator. The liquid electrolyte used was a mixture of 50 vol% ethylene carbonate and 50 vol% diethyl carbonate in which 1 mol of LiP F was dissolved₆The liquid electrolyte of (1).

The charge and discharge efficiency at a charge/discharge current rate of 0.1C, the life characteristics at a charge/discharge current rate of 0.2C, and the ion conductivity of each electrolyte observed using the button cell are shown in table 1 below.

[ Table 1]

As described above, the present invention has been described in terms of specific matters and limited embodiments, but this is provided only to facilitate the overall understanding of the present invention, and the present invention is not limited to the above-described embodiments, and those skilled in the art to which the present invention pertains may make various modifications and changes from these descriptions.

Therefore, the gist of the present invention is not limited to the embodiments described, and not only the contents described in the claims but also all modifications equivalent or equivalent to the claims are intended to fall within the scope of the gist of the present invention.