阅读说明：本技术 固体聚合物电解质组合物及含有其的固体聚合物电解质 (Solid polymer electrolyte composition and solid polymer electrolyte containing the same ) 是由 露西娅·金 李齐埙 蔡宗铉 韩东夹 张完洙 于 2019-09-20 设计创作，主要内容包括：本发明涉及固体聚合物电解质组合物和固体聚合物电解质,且更具体地涉及固体聚合物电解质组合物和通过将所述固体聚合物电解质组合物进行光固化而形成的固体聚合物电解质,所述固体聚合物电解质组合物含有：含有环氧烷且具有一个反应性双键的聚合物(A)；多官能可交联聚合物(B)；和离子液体,其中所述离子液体包含酰胺类溶剂和锂盐。(The present invention relates to a solid polymer electrolyte composition and a solid polymer electrolyte, and more particularly to a solid polymer electrolyte composition and a solid polymer electrolyte formed by photocuring the solid polymer electrolyte composition, the solid polymer electrolyte composition containing: a polymer (A) containing alkylene oxide and having one reactive double bond; a multifunctional crosslinkable polymer (B); and an ionic liquid, wherein the ionic liquid comprises an amide-based solvent and a lithium salt.)

1. A solid polymer electrolyte composition comprising a polymer (a) containing an alkylene oxide and having one reactive double bond, a polyfunctional crosslinkable polymer (B), and an ionic liquid, wherein the ionic liquid comprises an amide-based solvent and a lithium salt.

2. The solid polymer electrolyte composition according to claim 1, wherein the polymer (a) comprises polymerized units derived from any one monomer selected from the group consisting of: ethylene glycol methyl ether (meth) acrylate, ethylene glycol phenyl ether (meth) acrylate, diethylene glycol methyl ether (meth) acrylate, diethylene glycol 2-ethylhexyl ether (meth) acrylate, polyethylene glycol methyl ether (meth) acrylate, polyethylene glycol ethyl ether (meth) acrylate, polyethylene glycol 4-nonylphenyl ether (meth) acrylate, polyethylene glycol phenyl ether (meth) acrylate, ethylene glycol dicyclopentenyl ether (meth) acrylate, polypropylene glycol methyl ether (meth) acrylate, polypropylene glycol 4-nonylphenyl ether (meth) acrylate, or dipropylene glycol allyl ether (meth) acrylate, and combinations thereof.

3. The solid polymer electrolyte composition according to claim 1, wherein the multifunctional cross-linkable polymer (B) comprises polymerized units derived from any one monomer selected from the group consisting of: polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, divinylbenzene, polyester dimethacrylate, divinyl ether, ethoxylated bisphenol A dimethacrylate, tetraethylene glycol diacrylate, 1, 4-butanediol diacrylate, 1, 6-hexanediol diacrylate, di (trimethylolpropane) tetraacrylate, pentaerythritol ethoxylate tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, and combinations thereof.

4. The solid polymer electrolyte composition according to claim 1, wherein the amide-based solvent comprises at least one selected from the group consisting of: n-methylacetamide, N-dimethylformamide, 1-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, 2-pyrrolidone, -caprolactam, formamide, N-methylformamide, acetamide, N-dimethylacetamide, N-methylpropionamide and hexamethylphosphoric triamide.

5. The solid polymer electrolyte composition according to claim 1, wherein the content of the polymer (a) is 5 to 40 parts by weight with respect to 100 parts by weight of the entire composition.

6. The solid polymer electrolyte composition according to claim 1, wherein the content of the polymer (B) is 5 to 30 parts by weight with respect to 100 parts by weight of the entire composition.

7. The solid polymer electrolyte composition according to claim 1, wherein the content of the ionic liquid is 50 parts by weight to 90 parts by weight with respect to 100 parts by weight of the entire composition.

8. The solid polymer electrolyte composition according to claim 1, wherein the content of the lithium salt is 10 to 50 parts by weight with respect to 100 parts by weight of the entire composition.

9. The solid polymer electrolyte composition according to claim 1, wherein the amide-based solvent and the lithium salt are in a weight ratio of 40:60 to 60: 40.

10. The solid polymer electrolyte composition according to claim 1, wherein the lithium salt comprises any one selected from the group consisting of: LiPF₆、LiBF₄、LiSbF₆、LiAsF₆、LiOH、LiOH·H₂O、LiBOB、LiClO₄、LiN(C₂F₅SO₂)₂、LiN(CF₃SO₂)₂、CF₃SO₃Li、LiC(CF₃SO₂)₃、LiC₄BO₈、LiTFSI、LiFSI、LiClO₄And combinations thereof.

11. A solid polymer electrolyte formed by photocuring the solid polymer electrolyte composition of claim 1.

12. The solid polymer electrolyte of claim 11, wherein the thickness of the electrolyte is 50 μ ι η to 300 μ ι η.

13. The solid polymer electrolyte of claim 11, wherein the ionic conductivity of the electrolyte is 1.0 x 10 based on 25 ℃^-4S/cm to 2.0X 10^-3S/cm。

14. An all-solid battery comprising the solid polymer electrolyte according to claim 11.

Technical Field

This application claims priority based on korean patent application No. 10-2018-0113256, filed on 20/9/2018, the entire contents of which are incorporated herein by reference.

The present invention relates to a solid polymer electrolyte composition and a solid polymer electrolyte comprising the same.

Background

Lithium ion secondary batteries having high energy density, which are currently mainly used for notebook computers and smart phones, are composed of a positive electrode made of lithium oxide, a carbon-based negative electrode, a separator, and an electrolyte. Conventionally, as the above electrolyte, a liquid electrolyte, particularly an ion-conducting organic liquid electrolyte in which a salt is dissolved in a nonaqueous organic solvent, is mainly used. However, if the liquid electrolyte as described above is used, not only is the possibility of deterioration of the electrode material and volatilization of the organic solvent high, but there is also a problem of safety due to combustion caused by an increase in the ambient temperature and the temperature of the battery itself. In particular, the lithium secondary battery has problems in that gas is generated inside the battery due to decomposition of an organic solvent and/or a side reaction between the organic solvent and an electrode during charge and discharge to expand the thickness of the battery, and the reaction is accelerated and the amount of generated gas is further increased during high-temperature storage.

The gas thus generated continuously causes an increase in the internal pressure of the battery, which causes the rectangular battery to expand and explode in a specific direction or deform the center of a specific surface of the battery, resulting in a reduction in safety, and also causes a local difference in adhesion force at the electrode surface in the battery, resulting in a disadvantage that the electrode reaction does not occur equally in the entire electrode surface, thereby reducing the performance of the battery.

Therefore, until recently, active research has been conducted on polymer electrolytes for lithium secondary batteries to solve this problem of liquid electrolytes and replace it.

The polymer electrolyte is mainly classified into a gel type and a solid type. The gel-type polymer electrolyte is an electrolyte exhibiting conductivity by impregnating a high boiling point liquid electrolyte in a polymer film and fixing it together with a lithium salt. The solid type polymer electrolyte is in a form in which dissociated lithium cations are moved in a polymer by adding a lithium salt to the polymer containing a hetero element such as O, N and S.

The gel-type polymer electrolyte contains a large amount of liquid electrolyte and thus has ion conductivity similar to that of a pure liquid electrolyte. However, there are disadvantages in that stability problems and difficulties in the manufacturing process of the battery still remain.

On the other hand, in the case of a solid polymer electrolyte, it does not contain a liquid electrolyte, which improves stability problems related to leakage and also has the advantage of high chemical and electrochemical stability. However, since the ionic conductivity at room temperature is very low, many studies have been made to improve this.

Currently, the most commonly used material for solid polymer electrolytes is polyethylene oxide (PEO), which has the ability to conduct ions despite being solid. However, in the case of the linear PEO-based polymer electrolyte, the conductivity at room temperature is very low at 1.0X 10 due to high crystallinity^-5S/cm, and thus it is difficult to apply to a lithium secondary battery. In addition, the electrolyte has poor processability, insufficient mechanical strength, low voltage stability of less than 5V, and the like, and thus it is difficult to achieve satisfactory performance by applying it to a battery.

In order to solve these problems, attempts have been made to develop various materials, such as a hybrid polymer electrolyte, an interpenetrating network polymer electrolyte, and a non-woven solid polymer electrolyte, and apply them to a battery. However, there are still problems of low ionic conductivity and mechanical strength and narrow operating voltage range.

Therefore, the solid polymer electrolyte must have high ionic conductivity, suitable mechanical strength, and a wide operating voltage range, and also contain a minimum amount of solvent to ensure the operational stability of the battery.

[ Prior art documents ]

[ patent document ]

(patent document 1) Korean patent laid-open No. 2003-0097009(2003.12.31), "Polymer electrolyte having good leakage resistance and lithium battery using the same" (Polymer electrolyte with good leakage-resistance and lithium battery using the same "

Disclosure of Invention

[ problem ] to provide a method for producing a semiconductor device

Accordingly, as a result of various studies conducted to solve the above problems, the inventors of the present invention have confirmed that, if a solid polymer electrolyte is prepared by photocuring a solid polymer electrolyte composition comprising a polymer (a) containing an alkylene oxide and having one reactive double bond, a multifunctional crosslinkable polymer (B), and an ionic liquid containing an amide-based solvent and a lithium salt, the ionic conductivity of the electrolyte is improved, and the mechanical properties, flame retardancy, and electrochemical stability of the electrolyte are improved, thereby completing the present invention.

Accordingly, an object of the present invention is to provide a solid polymer electrolyte having the above-described effects, and to provide an all-solid battery comprising the solid polymer electrolyte and having improved performance.

[ technical solution ] A

In order to achieve the above object, the present invention provides a polymer electrolyte composition comprising a polymer (a) containing an alkylene oxide and having one reactive double bond, a multifunctional crosslinkable polymer (B), and an ionic liquid, wherein the ionic liquid comprises an amide-based solvent and a lithium salt.

One embodiment of the present invention comprises polymerized units derived from one monomer selected from the group consisting of: ethylene glycol methyl ether (meth) acrylate, ethylene glycol phenyl ether (meth) acrylate, diethylene glycol methyl ether (meth) acrylate, diethylene glycol 2-ethylhexyl ether (meth) acrylate, polyethylene glycol methyl ether (meth) acrylate, polyethylene glycol ethyl ether (meth) acrylate, polyethylene glycol 4-nonylphenyl ether (meth) acrylate, polyethylene glycol phenyl ether (meth) acrylate, ethylene glycol dicyclopentenyl ether (meth) acrylate, polypropylene glycol methyl ether (meth) acrylate, polypropylene glycol 4-nonylphenyl ether (meth) acrylate, or dipropylene glycol allyl ether (meth) acrylate, and combinations thereof.

In one embodiment of the present invention, the multifunctional crosslinkable polymer (B) comprises polymerized units derived from one monomer selected from the group consisting of: polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, divinylbenzene, polyester dimethacrylate, divinyl ether, ethoxylated bisphenol A dimethacrylate, tetraethylene glycol diacrylate, 1, 4-butanediol diacrylate, 1, 6-hexanediol diacrylate, di (trimethylolpropane) tetraacrylate, pentaerythritol ethoxylate tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, and combinations thereof.

In one embodiment of the present invention, the amide-based solvent comprises at least one selected from the group consisting of: n-methylacetamide, N-dimethylformamide, 1-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, 2-pyrrolidone, -caprolactam, formamide, N-methylformamide, acetamide, N-dimethylacetamide, N-methylpropionamide and hexamethylphosphoric triamide.

In one embodiment of the present invention, the content of the polymer (a) is 5 to 40 parts by weight with respect to 100 parts by weight of the entire composition.

In one embodiment of the present invention, the content of the polymer (B) is 5 to 30 parts by weight with respect to 100 parts by weight of the entire composition.

In one embodiment of the present invention, the content of the ionic liquid is 50 parts by weight to 90 parts by weight with respect to 100 parts by weight of the entire composition.

In one embodiment of the present invention, the content of the lithium salt is 10 to 50 parts by weight with respect to 100 parts by weight of the entire composition.

In one embodiment of the present invention, the weight ratio of the amide-based solvent to the lithium salt is 40:60 to 60: 40.

In one embodiment of the present invention, the lithium salt comprises any one selected from the group consisting of: LiPF₆、LiBF₄、LiSbF₆、LiAsF₆、LiOH、LiOH·H₂O、LiBOB、LiClO₄、LiN(C₂F₅SO₂)₂、LiN(CF₃SO₂)₂、CF₃SO₃Li、LiC(CF₃SO₂)₃、LiC₄BO₈、LiTFSI、LiFSI、LiClO₄And combinations thereof.

The present invention also provides a solid polymer electrolyte formed by photocuring the above solid polymer electrolyte composition.

In one embodiment of the present invention, the thickness of the electrolyte is 50 μm to 300 μm.

In one embodiment of the present invention, the ionic conductivity of the electrolyte is 1.0 × 10 based on 25 ℃^-4S/cm to 2.0X 10^-3S/cm。

The invention also provides an all-solid-state battery comprising the solid polymer electrolyte.

[ PROBLEMS ] the present invention

The solid polymer electrolyte formed by photocuring the solid polymer electrolyte composition according to the present invention is advantageous in that it can be effectively applied to all-solid batteries since the ion conductivity is improved and high mechanical stability, flame retardancy, and voltage stability are exhibited.

Drawings

FIG. 1 shows a measurement image of flame retardancy of a solid polymer electrolyte according to example 1 of the present invention.

FIG. 2 shows a measured image of the flame retardancy of the solid polymer electrolyte according to comparative example 1 of the present invention.

Detailed Description

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily practice the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the description herein.

The terms and words used in the present specification and claims should not be construed as being limited to general terms or dictionary terms, but interpreted as meanings and concepts conforming to the technical idea of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term to explain in the best possible manner.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. It will be understood that terms such as "comprising" or "having," when used in this specification, are intended to specify the presence of stated features, integers, steps, operations, elements, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Solid polymer electrolyte composition

The present invention relates to a solid polymer electrolyte composition and a solid polymer electrolyte having high ionic conductivity, excellent mechanical properties, and flame retardancy, and more particularly, to a solid polymer electrolyte composition comprising a polymer (a) containing an alkylene oxide and having one reactive double bond, a multifunctional crosslinkable polymer (B), and an ionic liquid, wherein the ionic liquid comprises an amide-based solvent and a lithium salt, and a solid polymer electrolyte formed by photocuring the solid polymer electrolyte composition.

In the case of a polymer electrolyte using conventional polyethylene oxide, there is a limitation of low ionic conductivity due to high crystallinity of the polymer structure. However, the polymer electrolyte according to one embodiment of the present invention exhibits flame retardancy and exhibits self-supporting mechanical properties by applying a polymer formed by crosslinking a polymer (a) containing an alkylene oxide and having one reactive double bond and a multifunctional crosslinkable polymer (B) and including an ionic liquid containing an amide-based solvent and a lithium salt. In addition, the crystallinity of the electrolyte is reduced, thereby improving the fluidity of the polymer chain, and also increasing the dielectric constant of the polymer, thus dissociating more lithium ions and exhibiting higher ionic conductivity than the existing polyethylene oxide polymer.

Therefore, the solid polymer electrolyte according to the present invention may be manufactured by using a solid polymer electrolyte composition comprising a polymer (a) containing an alkylene oxide and having one reactive double bond, a multifunctional crosslinkable polymer (B), and an ionic liquid, wherein the ionic liquid comprises an amide-based solvent and a lithium salt.

The polymer (a) comprises polymerized units derived from any one monomer selected from the group consisting of: ethylene glycol methyl ether (meth) acrylate [ EGME (M) A ], ethylene glycol phenyl ether (meth) acrylate [ EGPE (M) A ], diethylene glycol methyl ether (meth) acrylate [ DEGME (M) A ], diethylene glycol 2-ethylhexyl ether (meth) acrylate [ DEGEHE (M) A ], polyethylene glycol methyl ether (meth) acrylate [ PEGME (M) A ], polyethylene glycol ethyl ether (meth) acrylate [ PEGEE (M) A ], polyethylene glycol 4-nonylphenyl ether (meth) acrylate [ PEGNPE (M) A ], polyethylene glycol phenyl ether (meth) acrylate [ PEGPE (M) A ], ethylene glycol cyclopentenyl ether (meth) acrylate [ EGDCPE (M) A ], polypropylene glycol methyl ether (meth) acrylate [ PPGME (M) A ], polypropylene glycol 4-nonylphenyl ether (meth) acrylate or dipropylene glycol allyl ether (meth) acrylate, propylene glycol allyl ether (meth) acrylate [ EGDCPE (M) A ], propylene glycol methyl ether (meth) acrylate [ PPGME (M) A ], propylene glycol 4-nonylphenyl ether (meth) acrylate or dipropylene glycol, And mixtures thereof. The monomer-derived polymerized unit is a portion constituting the polymer, and refers to a portion derived from a specific monomer in the molecular structure of the polymer. For example, a polymerized unit derived from acrylonitrile refers to a moiety derived from acrylonitrile in the molecular structure of a polymer.

The polymer (a) may contain only one reactive double bond in the molecule to prevent excessive crosslinking with a crosslinkable polymer described later. If two or more reactive double bonds are present in the molecule, the ratio of ethylene oxide to the polymer (A) may decrease, thereby decreasing the ionic conductivity of the solid polymer electrolyte.

The content of the polymer (a) may be 5 to 40 parts by weight with respect to 100 parts by weight of the entire composition. If the amount of the polymer (A) is less than 5 parts by weight, the proportion of ethylene oxide contained in the polymer (A) may decrease, whereby the ionic conductivity of the electrolyte may decrease. If the amount of the polymer (A) exceeds 40 parts by weight, the content of the polymer (B) is relatively decreased, resulting in insufficient crosslinking, thereby decreasing the mechanical properties of the electrolyte, or the content of the lithium salt may be limited, thereby decreasing the ionic conductivity of the electrolyte. The amount of the polymer (A) is appropriately adjusted within the above range.

The polymer (B) comprises polymerized units derived from any one monomer selected from the group consisting of: polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane ethoxylate triacrylate, trimethylolpropane propoxylate triacrylate, polypropylene glycol dimethacrylate, polypropylene glycol diacrylate, divinylbenzene, polyester dimethacrylate, divinyl ether, ethoxylated bisphenol A dimethacrylate, tetraethylene glycol diacrylate, 1, 4-butanediol diacrylate, 1, 6-hexanediol diacrylate, di (trimethylolpropane) tetraacrylate, pentaerythritol ethoxylate tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane trimethacrylate, and combinations thereof. The polymer (B) contains two or more reactive double bonds in the molecule, so that the polymers included in the solid polymer electrolyte composition according to the present invention can be crosslinked with each other.

The content of the polymer (B) may be 5 to 30 parts by weight with respect to 100 parts by weight of the entire composition. If the amount of the polymer (B) is less than 5 parts by weight, it may be difficult to achieve sufficient crosslinking of the electrolyte composition, and the mechanical properties of the electrolyte may be reduced. If the amount of the polymer (B) exceeds 30 parts by weight, the content of the polymer (a) may be relatively reduced, or the content of lithium salt may be limited, thereby reducing the ionic conductivity of the electrolyte.

The solid polymer electrolyte composition according to the present invention includes an ionic liquid, and the ionic liquid may include an amide-based solvent and a lithium salt.

The ionic liquid is an ionic salt (or molten salt) consisting of a cation and an anion. Ionic compounds consisting of cations and non-metallic anions, such as sodium chloride, are generally referred to as ionic liquids, which are different from those that melt at high temperatures above 800 ℃, but exist as liquids at temperatures below 100 ℃. In particular, ionic liquids that exist as liquids at room temperature are referred to as Room Temperature Ionic Liquids (RTILs).

The ionic liquid is non-volatile, non-toxic and non-flammable, and has excellent thermal stability and ionic conductivity, compared to common liquid electrolytes. In addition, since the ionic liquid has a high polarity, it has unique properties of well dissolving inorganic compounds and organic metal compounds, and exists as a liquid in a wide temperature range, and thus takes advantage of the fact that various properties can be obtained by changing the structures of cations and anions constituting the ionic liquid, which is used in a wide range of chemical fields including catalysts, separations, and electrochemistry.

The content of the ionic liquid may be 50 parts by weight to 90 parts by weight based on 100 parts by weight of the entire composition, and it may further contain a lithium salt to form a so-called "dissolved ionic liquid (solvated ionic liquid)". If the ionic liquid is less than 50 parts by weight, the lithium salt may not be sufficiently dissolved in the ionic liquid, or the ionic conductivity of the entire electrolyte may be reduced. If the ionic liquid exceeds 90 parts by weight, the relative content of the polymer (A) or the polymer (B) decreases, the mechanical properties of the electrolyte may deteriorate, or the solid content of the all-solid battery may decrease, and an excessive amount of ionic liquid may remain, making it difficult to achieve a complete solid electrolyte. Therefore, the amount of the ionic liquid is appropriately adjusted within the above range.

The lithium salt may serve as a lithium ion source in the battery to enable basic operation of the lithium secondary battery, and serves to facilitate movement of lithium ions between the positive electrode and the negative electrode. The lithium salt may be any one selected from the group consisting of: LiPF₆、LiBF₄、LiSbF₆、LiAsF₆、LiOH、LiOH·H₂O、LiBOB、LiClO₄、LiN(C₂F₅SO₂)₂、LiN(CF₃SO₂)₂、CF₃SO₃Li、LiC(CF₃SO₂)₃、LiC₄BO₈、LiTFSI、LiFSI、LiClO₄And combinations thereof, but are not limited thereto.

The content of the lithium salt may be 10 to 50 parts by weight, preferably 20 to 50 parts by weight, and more preferably 30 to 50 parts by weight, with respect to 100 parts by weight of the total electrolyte composition. If the content of the lithium salt is less than 10 parts by weight, the ionic conductivity of the electrolyte may be reduced due to the low content. If the content of the lithium salt is 50 parts by weight or more, some lithium salt does not dissociate in the polymer electrolyte and exists in a crystalline state, and thus does not contribute to ion conductivity, but may rather impair ion conductivity, thereby lowering ion conductivity, and relatively lowering the polymer content, thereby impairing the mechanical strength of the solid polymer electrolyte. Therefore, the content of the lithium salt is appropriately adjusted within the above range.

The amide-based solvent may include at least one selected from the group consisting of: n-methylacetamide, N-dimethylformamide, 1-methyl-2-pyrrolidone, 1, 3-dimethyl-2-imidazolidinone, 2-pyrrolidone, -caprolactam, formamide, N-methylformamide, acetamide, N-dimethylacetamide, N-methylpropanamide, and hexamethylphosphoric triamide, and preferably may be N-methylacetamide (NMAC). The amide-based solvent has excellent thermal stability compared to succinonitrile used for preparing a conventional electrolyte, and has an advantage of being capable of preparing an electrolyte having improved stability with a battery negative electrode.

In one embodiment of the present invention, the weight ratio of the amide-based solvent and the lithium salt contained in the ionic liquid may be 40:60 to 60:40, preferably 45:55 to 55: 45. If the content of the amide-based solvent is less than the above range, the flame retardancy of the electrolyte achieved by including the amide-based solvent may be reduced. If the amide-based solvent exceeds the above range, the ionic conductivity of the electrolyte may be reduced due to the relatively low content of the lithium salt.

The polymer electrolyte according to one embodiment may exhibit excellent ionic conductivity. Specifically, the ionic conductivity of the polymer electrolyte may be 1.0 × 10 based on 25 ℃^-4S/cm to 2.0X 10^-3S/cm. When having an ionic conductivity within the above range, the all-solid battery containing the electrolyte according to the present invention can stably operate.

The thickness of the electrolyte according to an embodiment of the present invention is preferably 50 μm to 300 μm. As the thickness of the electrolyte is thinner, the energy density can be improved and the ionic conductivity can be increased. However, if the thickness is less than 50 μm, there is a problem in that appropriate mechanical strength of the electrolyte cannot be ensured. Therefore, the thickness is appropriately adjusted within the above range.

Method for preparing solid polymer electrolyte

In one embodiment of the present invention, a method of preparing a solid polymer electrolyte is provided. The electrolyte preparation method is not particularly limited, and methods known in the art may be used.

The preparation method comprises the following steps: (1) mixing lithium salt with an amide solvent; (2) mixing a polymer (A) containing alkylene oxide and having one reactive double bond with a polyfunctional crosslinkable polymer (B); (3) mixing the materials prepared in the step (1) and the step (2); and (4) photocuring the mixture of step (3) to obtain a solid polymer electrolyte. In the production method, the polymer (a) and the polyfunctional crosslinkable polymer (B) form a random copolymer by radical polymerization, and the crosslinking reaction is initiated by light or heat curing. Preferably, the mixture may be purged with nitrogen prior to step (4).

When the curing step is performed by photocuring, a photoinitiator may be further included. At least one photoinitiator selected from the group consisting of: DMPA (2, 2-dimethoxy-2-phenylacetophenone), HOMPP (2-hydroxy-2-methylpropiophenone), LAP (lithium phenyl-2, 4, 6-trimethylbenzoylphosphinate), IRGACURE 2959(1- [4- (2-hydroxyethoxy) -phenyl ] -2-hydroxy-2-methyl-1-propan-1-one), preferably, HOMPP (2-hydroxy-2-methylpropiophenone) may be used, but is not necessarily limited thereto. The photoinitiator is a photoinitiator capable of forming radicals by ultraviolet irradiation. If the concentration of the photoinitiator is too low, photopolymerization does not proceed efficiently, resulting in incomplete formation of a polymer electrolyte. If the concentration of the photoinitiator is too high, photopolymerization proceeds so rapidly that the uniformity of the polymer electrolyte may be reduced and applicability may be limited. Therefore, the photoinitiator may be used in an appropriate amount according to the desired physical properties of the electrolyte.

The photocuring may be performed by irradiating Ultraviolet (UV) rays to the electrolyte composition. In this case, there is an advantage that curing can be performed in a very fast time. The ultraviolet rays irradiated to the electrolyte composition may be ultraviolet rays having a wavelength of 254nm to 360 nm. Ultraviolet rays are rays of light having a wavelength shorter than that of violet visible rays, and are abbreviated as UV (ultraviolet rays). The ultraviolet rays are classified into ultraviolet rays A of long wavelength (320nm to 400nm), ultraviolet rays B of medium wavelength (280nm to 300nm), and ultraviolet rays C of short wavelength (100nm to 280 nm). When ultraviolet rays are irradiated to the electrolyte composition, the irradiation time of the ultraviolet rays may be 5 minutes to 30 minutes. However, the irradiation time of the ultraviolet ray (UV) may vary according to the intensity of the ultraviolet ray (UV) to be irradiated, and thus the irradiation time of the ultraviolet ray (UV) is not limited to the above range.

The method for preparing the electrolyte according to the present invention has advantages of in-situ polymerization through a single vessel reaction and simple process.

All-solid-state battery

In another embodiment of the present invention, the present invention provides an all-solid battery comprising the solid polymer electrolyte and an electrode.

The all-solid-state battery proposed in the present invention defines the constitution of the solid polymer electrolyte as described above, and other elements constituting the battery, i.e., the positive electrode and the negative electrode, are not particularly limited in the present invention, and the following description is followed.

The negative electrode for all-solid batteries is lithium metal alone or a material in which a negative electrode active material is laminated on a negative electrode current collector.

In this case, the anode active material may be any one selected from the group consisting of: lithium metal, lithium alloys, lithium metal composite oxides, lithium-containing titanium composite oxides (LTO), and combinations thereof. In this case, the lithium alloy may Be an alloy of lithium and at least one metal selected from Na, K, Rb, Cs, Fr, Be, Mg, Ca, Sr, Ba, Ra, Al, and Sn. In addition, the lithium metal composite oxide is an oxide (MeO) of lithium and any one metal (Me) selected from the group consisting of Si, Sn, Zn, Mg, Cd, Ce, Ni and Fe_x) May be, for example, Li_xFe₂O₃(x is more than 0 and less than or equal to 1) or Li_xWO₂(0＜x≤1)。

In addition, the negative active material may be a metal composite oxide, such as Sn_xMe_1-xMe'_yO_z(Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, elements of groups 1, 2 and 3 of the periodic table, halogen; x is more than 0 and less than or equal to 1; y is more than or equal to 1 and less than or equal to 3; and z is more than or equal to 1 and less than or equal to 8); oxides, e.g. SnO, SnO₂、PbO、PbO₂、Pb₂O₃、Pb₃O₄、Sb₂O₃、Sb₂O₄、Sb₂O₅、GeO、GeO₂、Bi₂O₃、Bi₂O₄And Bi₂O₅And a carbon-based anode active material such as crystalline carbon, amorphous carbon or carbon composite may be used alone or in combination of two or more.

In addition, the anode current collector is not particularly limited as long as it has conductivity without causing chemical changes in the all-solid battery. For example, copper, stainless steel, aluminum, nickel, titanium, sintered carbon; copper or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like; aluminum-cadmium alloy, etc. as the negative electrode current collector. In addition, the shape of the negative electrode current collector may be various forms such as a film, a sheet, a foil, a net, a porous body, a foam, a nonwoven fabric, and the like having fine irregularities on the surface, as in the positive electrode current collector.

The positive electrode for an all-solid battery according to the present invention is not particularly limited, and may be a material used for a known all-solid battery.

If the electrode is a positive electrode, it is a positive electrode current collector; if the electrode is an anode, it is an anode current collector.

The positive electrode current collector is not particularly limited so long as it has high conductivity without causing chemical changes in the associated battery. For example, stainless steel, aluminum, nickel, titanium, sintered carbon, or aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like can be used.

The positive active material may vary depending on the use of the lithium secondary battery, and a lithium transition metal oxide, such as LiNi, may be used_0.8-xCo_0.2Al_xO₂、LiCo_xMn_yO₂、LiNi_xCo_yO₂、LiNi_xMn_yO₂、LiNi_xCo_yMn_zO₂、LiCoO₂、LiNiO₂、LiMnO₂、LiFePO₄、LiCoPO₄、LiMnPO₄And Li₄Ti₅O₁₂(ii) a Chalcogenides, e.g. Cu₂Mo₆S₈FeS, CoS and MiS; and oxides, sulfides or halides, e.g. scandium, rutheniumOxides, sulfides or halides of titanium, vanadium, molybdenum, chromium, manganese, iron, cobalt, nickel, copper, zinc, more particularly, TiS can be used₂、ZrS₂、RuO₂、Co₃O₄、Mo₆S₈、V₂O₅Etc., but the present invention is not limited thereto.

The shape of the positive electrode active material is not particularly limited, and may be a particle shape such as a sphere, an ellipse, a rectangle, or the like. The average particle diameter of the cathode active material may be, but is not limited to, in the range of 1 μm to 50 μm. The average particle diameter of the positive electrode active material can be obtained, for example, by measuring the particle diameter of the active material observed by a scanning electron microscope and calculating the average value thereof.

The binder contained in the positive electrode is not particularly limited, and fluorine-containing binders such as polyvinylidene fluoride (PVDF) and Polytetrafluoroethylene (PTFE) may be used.

The content of the binder is not particularly limited as long as the positive electrode active material can be thereby fixed, and may be in the range of 0 to 10 wt% based on the entire positive electrode.

The positive electrode may further contain a conductive material. The conductive material is not particularly limited as long as it can improve the conductivity of the positive electrode, and examples thereof may include nickel powder, cobalt oxide, titanium oxide, and carbon. Examples of the carbon may include any one or more selected from the group consisting of ketjen black, acetylene black, furnace black, graphite, carbon fiber, and fullerene.

In this case, the content of the conductive material may be selected in consideration of other conditions of the battery such as the type of the conductive material, for example, may be in the range of 1 wt% to 10 wt% with respect to the entire positive electrode.

In the present invention, the preparation of the all-solid battery having the above-described constitution is not particularly limited, but may be carried out by a known method.

As one example, a solid electrolyte is placed between a positive electrode and a negative electrode, and then compression-molded to assemble a single cell (cell). In addition, the preparation may be performed in such a manner that the first polymer electrolyte layer of the polymer electrolyte is in contact with the positive electrode.

The assembled single cell is placed in an exterior material and sealed by heat pressing or the like. Laminated packages made of aluminum, stainless steel, or the like, and cylindrical or square metal containers are well suited as the exterior material.

Hereinafter, the present invention will be described in more detail with reference to examples and the like, but the scope and content of the present invention should not be construed as being reduced or limited by the following examples. In addition, based on the present disclosure including the following examples, it will be apparent to those skilled in the art that the present invention not specifically provided with experimental results can be easily implemented, and that such changes and modifications fall within the scope of the appended claims.