阅读说明：本技术 用于防止电极之间短路的全固态电池的阴极及其制造方法 (Cathode for all-solid-state battery for preventing short circuit between electrodes and method for manufacturing the same ) 是由 金容九 金润星 金智娜 金思钦 闵泓锡 于 2020-09-15 设计创作，主要内容包括：本发明公开了用于防止电极之间短路的全固态电池的阴极及其制造方法。一种制造用于全固态电池的阴极的方法,包括：在阴极集电器上堆叠保护构件,所述保护构件包括保护层和设置在保护层上的掩模层,并且具有作为空的空间的中心部分；用阴极材料涂覆保护构件,使得保护构件的中心部分填充有阴极材料；并且移除掩模层,以形成阴极涂层。(The invention discloses a cathode of an all-solid-state battery for preventing short circuit between electrodes and a method of manufacturing the same. A method of making a cathode for an all-solid-state battery, comprising: stacking a protective member on the cathode current collector, the protective member including a protective layer and a mask layer disposed on the protective layer and having a central portion as an empty space; coating the protective member with a cathode material such that a central portion of the protective member is filled with the cathode material; and removing the mask layer to form a cathode coating.)

1. A method of manufacturing a cathode for an all-solid battery, the method comprising:

stacking a protective member on a cathode current collector, the protective member including a protective layer and a mask layer disposed on the protective layer, and the protective member having a central portion as an empty space;

coating the protective member with a cathode material such that the central portion of the protective member is filled with the cathode material; and is

Removing the mask layer to form a cathode coating.

2. The method of claim 1, wherein the mask layer comprises polyethylene naphthalate (PEN), and

wherein the protective layer comprises polyethylene naphthalate (PEN).

3. The method of claim 1, wherein the mask layer is disposed on an upper surface of the protective layer.

4. The method of claim 3, wherein an adhesive is interposed between the protective layer and the mask layer.

5. The method according to claim 1, wherein an adhesive layer is interposed between the cathode current collector and the protective member when the protective member is stacked, and

wherein the adhesive layer comprises any one selected from the group consisting of: ethylene Vinyl Acetate (EVA) copolymers, polyvinyl acetate (PVA), Polyethylene (PE), amorphous polypropylene, thermoplastic elastomers, polyamides, polyesters, and combinations thereof.

6. The method of claim 1, wherein the protective member is stacked on the cathode current collector by applying at least one of heat or pressure.

7. The method according to claim 1, wherein, when removing the mask layer, the mask layer and the cathode material coated on the mask layer are removed, and the cathode material is maintained in a shape of inserting the central portion of the protective layer as the cathode coating layer.

8. The method of claim 1, wherein a thickness of the cathode material is greater than or equal to a sum of a thickness of the protective layer and a thickness of the mask layer.

9. The method of claim 1, wherein the thickness of the cathode coating is greater than or equal to the thickness of the protective layer.

10. The method of claim 1, further comprising: stamping the protective layer, the cathode coating layer, and the cathode current collector after removing the mask layer.

11. The method according to claim 10, wherein the punching of the protective layer, the cathode coating layer, and the cathode current collector is performed at a predetermined interval from a central portion of the protective layer, and

wherein the upper and lower surfaces of the punched protective layer have any one shape of a circle and a polygon.

12. A cathode for an all-solid-state battery, the cathode comprising:

a cathode current collector;

a cathode coating disposed on the cathode current collector; and

an insulating layer disposed on the cathode current collector, the insulating layer having a central portion as an empty space,

wherein an upper surface of the central portion has any one of a circular shape and a polygonal shape, and

the cathode coating is disposed at the central portion such that a portion of an outer side surface of the cathode coating and a side surface of the central portion contact each other.

13. The cathode of claim 12, wherein the cathode current collector comprises any one selected from the group consisting of: nickel, copper, zinc, aluminum, and combinations thereof.

14. The cathode of claim 12, wherein the cathode coating comprises an active material and a binder.

15. The cathode of claim 12, wherein the insulating layer comprises an insulator.

16. The cathode of claim 12, wherein the insulating layer comprises polyethylene naphthalate (PEN).

17. The cathode of claim 12, wherein the insulating layer has a thickness of 0.80 to 1.30 times the thickness of the cathode coating.

18. The cathode of claim 12, wherein the insulating layer has a thickness of 100 μ ι η or less and the cathode coating has a thickness of 80 to 115 μ ι η.

19. The cathode of claim 12, wherein the insulating layer has an inner diameterEqual to the diameter of the cathode coatingAnd is

Wherein the outer diameter of the insulating layerThe following expression 1 is satisfied,

[ expression 1]

20. An all-solid battery comprising:

a cathode according to claim 12;

an anode; and

a solid electrolyte interposed between the cathode and the anode.

Technical Field

The present disclosure relates to a cathode for an all-solid battery and a method of manufacturing the same, and more particularly, to a cathode for an all-solid battery and a method of manufacturing the same, which can prevent a short circuit between electrodes by coating an insulating layer having insulating properties on the cathode.

Background

A secondary battery is a battery that repeatedly charges and discharges by bidirectionally converting chemical energy and electrical energy through oxidation/reduction chemical reactions, and generally includes four basic elements, i.e., a cathode, an anode, a separator, and an electrolyte. At the electrodes (including the cathode and the anode), a material that actually causes a reaction between electrode material components is referred to as an active material.

For the lithium ion secondary battery, a liquid electrolyte and an electrolyte including a liquid are used. However, liquid electrolytes are disadvantageous due to volatility, explosion risk and low thermal stability. In contrast, an all-solid battery using a solid electrolyte has a low explosion risk and excellent thermal stability. In addition, bipolar plates are used to stack the electrodes to achieve a series connection, thereby generating a high operating voltage. Therefore, a higher energy density is expected compared to a battery using a liquid electrolyte in parallel.

Unlike conventional batteries using liquid electrolytes, the problem of electrode-electrolyte contact occurs in large amounts in all-solid batteries. Since the all-solid battery transfers lithium ions through solid-solid contact, an additional pressurization or heat treatment process between electrodes and an electrolyte is necessary in order to improve contact between the electrodes and the electrolyte when the batteries (cells) are stacked. When the applied pressure is large, the contact between the electrode and the electrolyte is improved, thereby enhancing the battery characteristics. However, in this case, the battery is internally short-circuited more frequently. Furthermore, in the case of a battery pack (cell stack) rather than a single cell, cell short circuits occur more frequently due to non-uniform stress caused by area mismatch when electrodes are stacked.

The information contained in the background section is only for enhancement of understanding of the general background of the disclosure and is not to be taken as an admission or any form of suggestion that this information forms the prior art known to a person skilled in the art.

Disclosure of Invention

An object of the present disclosure is to solve the problem of short circuit in the electrode manufacturing process.

Another object of the present disclosure is to provide a structure capable of reducing electrode short circuits and a defect rate.

Another object of the present disclosure is to improve workability by realizing continuous processing when manufacturing an electrode for an all-solid battery.

The objects of the present disclosure are not limited to the foregoing and will be clearly understood through the following description and can be achieved by the means described in the claims and combinations thereof.

According to an exemplary embodiment of the present disclosure, a method of manufacturing a cathode for an all-solid battery includes: preparing a protective member including a protective layer and a mask layer disposed on the protective layer, the protective member having a central portion therein as an empty space; stacking a protective member on the cathode current collector, the protective member including a protective layer and a mask layer disposed on the protective layer and having a central portion, which is an empty space in which the protective member is coated with a cathode material such that the central portion of the protective member is filled with the cathode material; and removing the mask layer to form a cathode coating.

The mask layer may include polyethylene naphthalate (PEN), and the protective layer may include polyethylene naphthalate (PEN).

In preparing the protective member, a mask layer may be stacked on an upper surface of the protective layer, and a release sheet may be attached to a lower surface of the protective layer.

An adhesive may be interposed between the protective layer and the mask layer.

In stacking the protection member, the adhesive layer may be interposed between the cathode current collector and the protection member, and the adhesive layer may include any one selected from the group consisting of: ethylene Vinyl Acetate (EVA) copolymers, polyvinyl acetate (PVA), Polyethylene (PE), amorphous polypropylene, thermoplastic elastomers, polyamides, polyesters, and combinations thereof.

The protective member may be stacked on the cathode current collector using heat and/or pressure.

In removing the mask layer, the mask layer and the cathode material coated on the mask layer may be removed, and the cathode material may be maintained in a shape inserted into a central portion of the protective layer to form a cathode coating layer.

The thickness L3 of the cathode material may be greater than or equal to the sum of the thickness L1 of the protective layer and the thickness L2 of the mask layer.

The thickness L3' of the cathode coating may be greater than or equal to the thickness L1 of the protective layer.

The method of the present disclosure may further include stamping the protective layer, the cathode coating layer, and the cathode current collector after removing the mask layer.

The protective layer, the cathode coating layer, and the cathode current collector may be punched at positions spaced apart from a central portion of the protective layer by a predetermined interval, and upper and lower surfaces of the punched protective layer may have any one of a circular shape and a polygonal shape.

According to another exemplary embodiment of the present disclosure, a cathode for an all-solid battery includes: a cathode current collector; a cathode coating layer formed on the cathode current collector; and an insulating layer disposed on the cathode current collector, the insulating layer having a central portion as an empty space, wherein an upper surface of the central portion has any one of a circular shape and a polygonal shape, and the cathode coating is inserted into the central portion such that a portion of an outer side surface of the cathode coating and a side surface of the central portion contact each other.

The cathode current collector may include any one selected from the group consisting of nickel, copper, zinc, aluminum, and combinations thereof.

The cathode coating may include an active material and a binder.

The insulating layer may include an insulator.

The insulating layer may include polyethylene naphthalate (PEN).

The thickness of the insulating layer may be 0.80 to 1.30 times the thickness of the cathode coating.

The insulating layer may have a thickness of 100 μm or less, and the cathode coating may have a thickness of 80 μm to 115 μm.

Inner diameter of insulating layerMay be equal to the diameter of the cathode coatingAnd the outer diameter of the insulating layerThe following expression 1 can be satisfied.

[ expression 1]

Further, the present disclosure provides an all-solid battery including the above-described cathode, anode, and solid electrolyte interposed between the cathode and the anode.

According to the present disclosure, a short circuit problem in manufacturing an electrode can be solved.

According to the present disclosure, a novel structure capable of reducing electrode short-circuiting and a defect rate may be provided.

According to the present disclosure, when manufacturing an electrode for an all-solid battery, workability can be increased by implementing continuous processing, and economic benefits can be obtained.

The effects of the present disclosure are not limited to the foregoing, and should be understood to include all effects that can be reasonably expected from the following description.

Drawings

Fig. 1 schematically illustrates a process for manufacturing a cathode for an all-solid battery according to the present disclosure;

fig. 2 illustrates thicknesses of components included in a cathode of an all-solid battery according to the present disclosure;

fig. 3 shows side and top views of a cathode of an all-solid battery according to the present disclosure before and after a stamping process;

FIGS. 4A, 4B and 4C show the diameters of the insulating layer, cathode coating, anode and solid electrolyte according to the invention;

fig. 5 shows a Scanning Electron Microscope (SEM) image of a cross-section of an all-solid-state battery fabricated in example 1 according to the present disclosure;

fig. 6 shows a charge/discharge curve of an all-solid battery manufactured in example 1 according to the present disclosure; and

fig. 7 shows the charging result in the case of comparative example 1.

Detailed Description

The above and other objects, features and advantages of the present disclosure will be more clearly understood from the following description of preferred embodiments taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed herein, and may be modified into different forms. These embodiments are provided so that this disclosure will be thorough and will fully convey the spirit of the disclosure to those skilled in the art.

The same reference numbers will be used throughout the drawings to refer to the same or like elements. For clarity of the disclosure, the dimensions of the structures are depicted as being larger than their actual dimensions. It will be understood that, although terms such as "first," "second," etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a "first" element discussed below could be termed a "second" element without departing from the scope of the present disclosure. Similarly, a "second" element may also be referred to as a "first" element. As used herein, the singular forms are also intended to include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "has," "having," and the like, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof. Further, it will be understood that when an element such as a layer, film, region, or sheet is referred to as being "on" another element, it can be directly on the other element or intervening elements may be present therebetween. Similarly, when an element such as a layer, film, region, or sheet is referred to as being "under" another element, it can be directly under the other element or intervening elements may be present therebetween.

Unless otherwise indicated, all numbers, values, and/or expressions referring to amounts of components, reaction conditions, polymer compositions, and mixtures used herein are to be considered approximate, including the various uncertainties affecting measurements that occur primarily in the process of obtaining such values, and thus are understood to be modified in all instances by the term "about. Further, when a range of values is disclosed in this specification, the range is continuous and includes all values from the minimum value to the maximum value of the range unless otherwise specified. Further, when such ranges fall within integer values, all integers including the minimum to maximum values are included unless otherwise specified.

In this specification, when a range of a variable is described, it is understood that the variable includes all values, including the endpoints described in the range. For example, a range of "5 to 10" will be understood to include any subrange, e.g., 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., as well as individual values of 5, 6, 7, 8, 9, and 10, and will also be understood to include any value between the effective integers within the range, e.g., 5.5, 6.5, 7.5, 5.5 to 8.5, 6.5 to 9, etc. Further, for example, a range of "10% to 30%" will be understood to include any sub-range (e.g., 10% to 15%, 12% to 18%, 20% to 30%, etc.) and all integers including values of 10%, 11%, 12%, 13%, etc. up to 30%, and will also be understood to include any value between the effective integers within the range, e.g., 10.5%, 15.5%, 25.5%, etc.

The present disclosure relates to a method of manufacturing a cathode for an all-solid battery and a cathode for an all-solid battery manufactured by the method. A method of manufacturing a cathode of an all-solid battery disclosed as a method and a cathode of an all-solid battery disclosed as a product are described below.

Here, description of overlapping features in the method disclosure and the product invention will be omitted.

Method of manufacturing cathode for all-solid battery

A method of manufacturing a cathode for an all-solid battery according to the present disclosure includes: preparing a protective member including a protective layer and a mask layer disposed on the protective layer and having a plurality of central portions therein, the plurality of central portions being empty spaces; stacking a protective member on the cathode current collector; coating the protective member with a cathode material such that a central portion of the protective member is filled with the cathode material; and removing the mask layer to form a cathode coating.

Fig. 1 illustrates steps of manufacturing a cathode of an all-solid battery according to the present disclosure and formation of the cathode through the respective steps.

The respective steps are described in detail with reference to fig. 1.

Preparation (S1)

A protective member 10 is prepared, the protective member 10 including a protective layer 12 and a mask layer 11 provided on the protective layer 12, and having a central portion 20 therein, the central portion 20 being a columnar empty space. More specifically, the protective member 10 is configured such that the protective layer 12 and the mask layer 11 are stacked in contact with each other, and the protective layer 12 and the mask layer 11 have holes formed in a predetermined pattern. Here, the pattern is formed of a plurality of circles or polygons, but this is only an option that can be selected according to the purpose of the present invention, and the present disclosure is not limited thereto.

The mask layer 11 needs to be formed of a material resistant to a solvent or the like contained in the cathode material 40. In particular, in an all-solid battery, a nonpolar solvent (e.g., xylene or heptane) may be used, and thus a material resistant thereto may be used.

Specifically, the mask layer 11 includes polyethylene naphthalate (PEN).

The protective layer 12 needs to be formed of a material that is resistant to the solvent and the like contained in the cathode material 40. The material should be able to withstand a certain temperature (e.g., about 120 ℃) when drying the electrode, and preferably, the coefficient of thermal expansion of the material is similar to that of the cathode current collector 30.

Specifically, the protective layer 12 includes polyethylene naphthalate (PEN).

The cathode current collector 30 serves to transport electrons generated from the cathode coating layer 40', and may include any one selected from the group consisting of nickel, copper, zinc, aluminum, and a combination thereof.

The mask layer 11 is stacked on the upper surface of the protective layer 12, and a peeling sheet may be attached to the lower surface of the protective layer 12. Here, the release sheet may be removed before the protection member 10 is attached to the upper surface of the cathode current collector 30.

The protective layer 12 and the mask layer 11 are stacked in contact with each other, and an adhesive may be interposed between the protective layer 12 and the mask layer 11.

The adhesive is used to prevent the protective layer 12 and the mask layer 11, which are stacked on each other, from being deformed, or to prevent the cathode material 40 from penetrating between the mask layer 11 and the protective layer 12 when the cathode material 40 is coated, by appropriately selecting the adhesiveness of the adhesive. Furthermore, it serves to facilitate the removal of the mask layer 11 from the protective layer 12 without using a large force.

The adhesive may comprise a silicon-based Pressure Sensitive Adhesive (PSA) that is easily removable.

The PSA includes an acrylate or a siloxane, and may further include any one selected from the group consisting of ester rubbers, phenolic resins, castor oil, polyisobutylene, and combinations thereof.

The adhesive (including silicone) of the present disclosure has excellent heat resistance, cold resistance, water resistance, insulating properties, ozone resistance, low flammability, chemical inertness, and non-polluting, does not melt at high temperatures, and exhibits flexibility and adhesiveness even at very low temperatures.

In order to enhance the adhesion, a silicone adhesive composition containing any one functional group selected from the group consisting of a hydroxyl group, an alkoxy group, an epoxy group, and a combination thereof may be used as the adhesive.

Stacking (S2)

The protective member 10 is stacked on the cathode current collector 30. Here, the protection member 10 may be stacked on the cathode current collector 30 using heat and/or pressure.

In addition, an adhesive layer may be interposed between the cathode current collector 30 and the protective member 10. More specifically, the adhesive layer may be interposed between the cathode current collector 30 and the protective layer 12 of the protective member 10.

The adhesive layer needs to be formed of a material resistant to a solvent or the like contained in the cathode material 40 and should be able to withstand the electrode drying temperature (e.g., about 120 ℃). In addition, the thermal expansion coefficient may be similar to that of the cathode current collector 30. The adhesive layer is different from the adhesive of the present disclosure in that the protective layer 12 and the cathode current collector 30 are attached so that they are not separated from each other.

The adhesive layer may include a thermoplastic adhesive, and particularly, the thermoplastic adhesive includes any one selected from the group consisting of Ethylene Vinyl Acetate (EVA) copolymer, polyvinyl acetate (PVA), Polyethylene (PE), amorphous polypropylene, thermoplastic elastomer, polyamide, polyester, and a combination thereof.

The above thermoplastic adhesive is coated so that an adhesive layer having a uniform adhesive surface can be continuously manufactured and formed.

Coating (S3)

The protective member 10 is coated with the cathode material 40 such that the central portion 20 of the protective member 10 is filled with the cathode material 40. Specifically, the cathode material 40 is coated on the central portion 20 of the protective member 10, which is an empty space forming a predetermined pattern, and is coated on the mask layer 11 of the protective member 10, whereby the central portion 20 is filled with the cathode material 40. Although the mask layer 11 may be completely covered by the cathode material 40, only the central portion 20 may be filled, instead of the mask layer 11, as needed.

The cathode material includes an active material, a binder, and a solvent, and may further include a conductor for increasing electrical conductivity as needed. Here, the binder, the solvent, and the conductor may be materials generally used in conventional secondary batteries and the like, and are not particularly limited in the present disclosure.

It is sufficient that the active material can be used in the all-solid-state battery technology field, for example, Nickel Cobalt Manganese (NCM), Nickel Cobalt Aluminum (NCA), Lithium Manganese Oxide (LMO), Lithium Cobalt Oxide (LCO), Nickel Manganese Oxide (NMO), and the like can be included in the active material.

After the coating process, drying of the electrode material may be further performed.

By the drying process, the solvent is removed from the electrode material, and the density of the active material and the binder contained in the electrode material can be further increased.

Removing (S4)

The cathode coating layer 40' is formed by removing the mask layer 11 from the protective member 10. Specifically, when the cathode material 40 is coated on the mask layer 11, the cathode material 40 coated on the mask layer 11 is removed together with the mask layer 11. Here, only the cathode coating 40' remains dried in the form of the interposed central portion 20. More specifically, the cathode coating 40' is left in a columnar form having a pattern shape of the central portion 20. Accordingly, the mask layer 11 is removed, whereby the thickness of the cathode coating 40' comprised in the central portion 20 is naturally greater than the thickness of the protective layer 12.

After the removal process, the cathode coating 40 'is pressurized, thereby further increasing the density of the active material and binder contained in the cathode coating 40'. Here, the thickness of the cathode coating layer 40' may be equal to or less than the thickness of the protective layer 12. Fig. 2 shows the thickness of the cathode material 40 after the coating process, the thickness of the cathode coating 40' after the removal process, and the variation in the thickness of the protective layer 12 and the mask layer 11. As shown in fig. 2, the thickness L3 of the cathode material 40 is greater than the sum of the thickness L1 of the protective layer 12 and the thickness L2 of the mask layer 11, and after removing the mask layer 11, the thickness L3 'of the cathode coating 40' is greater than the thickness L1 of the protective layer 12. Subsequently, when pressure is applied to the cathode coating 40 ', the thickness L3 ' of the cathode coating 40 ' may be equal to the thickness L1 of the protective layer 12.

According to the present disclosure, the thickness L1 of the protective layer 12 is 0.80 to 1.30 times, preferably 0.85 to 1.25 times, the thickness L3 'of the cathode coating 40'. If the thickness of the protective layer 12 is less than 0.80 times or more than 1.30 times the thickness of the cathode coating 40 ', the stack of the electrolyte and the anode formed on the cathode including the cathode coating 40' may not be flat and there is a risk of internal short circuit.

In the present disclosure, the stamping process may be further performed after the removing process. A stamping process is performed to form a predetermined shape of the protective layer 12, the cathode coating layer 40', and the cathode current collector 30, which are laminated together.

The punching process is performed at a position spaced apart from the central portion 20 of the protective layer 12 by a predetermined interval, and the upper and lower surfaces of the punched protective layer 12 have a circular shape or a polygonal shape.

Fig. 3 illustrates a stamping process in which the upper and lower surfaces of the protective layer 12 have a circular shape, according to an embodiment of the present disclosure. In this regard, the cathode coating layer 40' is provided in the form of being inserted into the plurality of central portions 20 of the protective layer 12, and the punching process is performed in a circular shape at a position spaced apart from each of the plurality of central portions 20 of the protective layer 12 by a predetermined interval. The stamping process makes the protective layer 12 and the cathode current collector 30 circular in appearance.

An all-solid battery is manufactured from each of the plurality of central portions 20 of the protective layer 12, whereby the cathode including the protective layer 12 can be mass-produced by a single process.

Cathode for all-solid-state battery

According to the present disclosure, a cathode for an all-solid battery includes a cathode current collector 30, a cathode coating layer 40 'having a cylindrical shape formed on the cathode current collector 30, and an insulating layer 12' disposed on the cathode current collector 30 and having a central portion 20 therein, the central portion 20 being a cylindrical empty space.

Specifically, the upper surface of the central portion 20 has a circular shape, and the cathode coating 40 'is inserted into the central portion 20 such that a portion of the outer side surface of the cathode coating 40' and the side surface of the central portion 20 contact each other.

Here, the insulating layer 12 'is formed of the same type of material as the protective layer 12 of the present disclosure, and the insulating layer 12' is configured to include only one central portion 20, unlike the protective layer 12 in the form of a plate having a plurality of central portions 20 in a manufacturing method. The insulating layer 12' can be obtained by stamping the protective layer 12, and there is no difference in material between them.

Referring again to fig. 3, the protective layer 12 is shown on the left before the stamping process and the insulating layer 12' is shown on the right after the stamping process.

The insulating layer 12' may comprise an insulator. The insulating layer 12' serves to prevent a short circuit between the electrodes or between the electrodes and the electrolyte. As the insulator, any material may be used without particular limitation as long as the flow of electrons can be interrupted.

The thickness of the insulating layer 12 'may be less than or equal to the thickness of the cathode coating 40', as shown in fig. 2.

The insulating layer 12 'has a thickness of 100 μm or less, and the cathode coating layer 40' has a thickness of 80 μm to 115 μm.

Fig. 4A to 4C illustrate the outer and inner diameters of the insulating layer 12 'having a circular shape and the diameter of the cathode coating 40' according to an embodiment of the present disclosure. In this regard, FIG. 4A shows the inner diameter of the insulating layer 12And the outer diameter of the insulating layer 12Inner diameterEqual to the diameter of the central portion 20 of the insulating layer 12Diameter, outside diameterEqual to the diameter of the punched pattern.

FIG. 4B shows the diameter of the cathode coating 40' formed in the central portion 20 of the insulating layer 12Wherein the cathode coating 40 'is completely encased and inserted into the central portion 20 of the insulating layer 12'. Thus, the diameter of the cathode coating 40Equal to the diameter of the central portion 20. Specifically, the diameter of the cathode coating 40Equal to the inner diameter of the insulating layer 12

In the present disclosure, the outer diameter of the insulating layer 12The following expression 1 is satisfied.

[ expression 1]

Preferably, the outer diameter of the insulating layer 12The following expression 2 is satisfied.

[ expression 2]

Here, if the outer diameter of the insulating layer 12' is smaller thanThe area of the insulating layer 12' is excessively small and thus the insulating layer cannot serve as an insulator for preventing a short circuit between the electrodes. On the other hand, if its outer diameter exceedsThe area of the cathode coating 40' may be reduced, thereby deteriorating the cell performance and efficiency.

In the present disclosure, when the insulating layer 12 'has a polygonal shape instead of a circular shape, the central portion has a polygonal shape corresponding to the shape of the insulating layer 12'. At this point in time,the outer diameter of the insulating layer having a polygonal shape is shown,an inner diameter of the insulating layer in a direction of measuring the outer diameter is represented, which satisfies the following expression 3.

[ expression 3]

When the insulating layer 12' has a polygonal shape, the shape of the cathode coating inserted into the central portion may be a polygon according to the polygonal shape described above.

All-solid-state battery

According to the present disclosure, the all-solid battery includes a cathode for the all-solid battery of the present disclosure, an anode 60, and a solid electrolyte 50 interposed between the cathode and the anode 60.

Fig. 4C shows a cathode of the present invention, including a cathode current collector 30, an insulating layer 12 ', and a cathode coating 40', in which a solid electrolyte 50 and an anode 60 are stacked on the cathode.

The present disclosure relates to a cathode for a battery including the solid electrolyte 50, and the type of the anode 60 or the solid electrolyte 50 is not particularly limited.

For example, LISICON-based compounds, thioLISCON-based compounds, lithium sulfide (Li)₂S) compound, lithium sulfide (Li)₂S) -phosphorus disulfide (P)₂S₅) A mixture of (a), an azetidinium-based compound, etc. may be used as the solid electrolyte 50.

The diameters of the anode 60 and the solid electrolyte 50 are equal to each other, and the diameters of the anode 60 and the solid electrolyte 50 are equal to each otherIt needs to be larger than the diameter of the cathode coating 40Or the inner diameter of the insulating layer 12And is smaller than the outer diameter of the insulating layer 12If the diameter falls outside the above range, there is a risk of short-circuiting between the electrodes, and the battery efficiency may be reduced.

The present disclosure will be better understood from the following embodiments. However, these examples are presented merely to illustrate the present disclosure and should not be construed as limiting the scope of the present disclosure.

Example 1

A protective member configured such that a protective layer (PEN film) having a thickness of about 90 μm and a mask layer (PEN film) having a thickness of 30 μm were sequentially attached to the upper surface of the release film was punched to form the central portion of a circular pattern having a diameter of 14mm, the release film was removed, and the protective member was thermally fused by heating at 100 ℃ to the cathode current collector (aluminum foil) having the polyethylene film attached thereto. Here, a silicone adhesive is interposed between the protective layer and the mask layer.

Coating a mask layer and a cathode current collector including lithium cobalt oxide (LiCoO) on the mask layer and the cathode current collector exposed through the central portion₂) Carbon black and polyvinylidene fluoride (PVdF), and dried in vacuum for 8 hours.

Thereafter, the mask layer and the dried cathode material on the mask layer were removed, and pressure was applied using a press machine so that the average thickness of the cathode coating layer remaining in the form of the interposed central portion was 100 μm.

The cathode current collector including the protective layer and the cathode coating was punched into a circular pattern having a diameter of 18 mm.

Thereafter, a solid electrolyte having a diameter of 16mm and comprising lithium (Li), lanthanum (La), zirconium (Zr), oxide (O) and polyvinylidene fluoride and an anode comprising graphite and polyvinylidene fluoride were sequentially stacked and pressed to respective average thicknesses of 40 μm and 90 μm, thereby manufacturing an all-solid battery in which the amounts of the cathode, the anode and the electrolyte were 23.22mg/cm, respectively²、15.33mg/cm²And 6.18mg/cm²)。

Fig. 5 shows a sectional image of the all-solid battery of example 1 manufactured as described above. In this connection, it was confirmed that the cathode coating layer and the insulating layer had almost the same thickness, and thus the side surface of the cathode was completely protected by the insulating layer.

Fig. 6 is a charge/discharge diagram of the all-solid battery manufactured as described above, specifically, after 200 charge/discharge cycles at a voltage (V) of 2.5 to 4.3. In this connection, it was confirmed that stable charge/discharge results were exhibited even when the solid electrolyte was thin.

Comparative examples 1 to 3

On the cathode current collector, a coating including lithium cobalt oxide (LiCoO)₂) Carbon black and polyvinylidene fluoride (PVdF), and dried in vacuum for 8 hours, and then pressure was applied thereto using a press machine to obtain an average thickness of 100 μm. The cathode current collector coated with the cathode material was punched into a circular pattern having a diameter of 18 mm.

Thereafter, the same solid electrolyte and anode as in example 1 were prepared and stacked in order, thereby manufacturing three all-solid batteries.

The three all-solid batteries (specifically, the batteries of comparative example 1(E1), comparative example 2(E2), and comparative example 3 (E3)) were subjected to a charge test. The results are shown in FIG. 7. In this regard, it can be seen that these batteries do not operate as ordinary batteries. This is considered to be caused by a short circuit between the cathode and the anode due to the difference in area between the cathode and the anode resulting in breakage of the solid electrolyte at the boundary portion when the battery is pressurized.

As is apparent from the results of example 1 and comparative examples 1 to 3, a protective member including a protective layer and a mask layer was applied, whereby the patterned cathode coating layer and the insulating layer can be effectively aligned with each other. Further, the edge of the cathode coating is protected by the insulating layer, and thus, when the all-solid battery is pressurized, the problems of the breakage of the solid electrolyte contacting the edge portion of the cathode coating and the short circuit between the electrodes are solved, and finally, stable charge and discharge performance can be achieved.

Although the embodiments of the present disclosure have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications are possible without departing from the scope and spirit of the present disclosure as disclosed in the appended claims, and that such modifications should not be construed as being apart from the technical ideas or essential features of the present disclosure.