All-solid-state battery and method for manufacturing the same

Abstract

To provide an all-solid-state battery with improved yield.SOLUTION: An all-solid-state battery includes a positive electrode active material layer 10, a solid electrolyte layer 20, and a negative electrode active material layer 30 in this order, and further includes an insulating member 40 in contact with the outer periphery of the solid electrolyte layer 20, and at least a portion of the solid electrolyte layer 20 is located in a region S surrounded by the positive electrode active material layer 10 and the insulating member 40.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an all-solid-state battery and a method for manufacturing an all-solid-state battery. [Background technology]

[0002] There is a method for manufacturing an all-solid-state battery that includes a step of pressing a structure having a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer.

[0003] Patent Document 1 describes a method for manufacturing an all-solid-state battery, with the aim of providing a method for manufacturing an all-solid-state battery capable of improving adhesion between a current collecting layer and a composite layer, including the steps of: preparing a first current collecting layer having an adhesive layer; stacking the first composite layer, a solid electrolyte layer, a second composite layer, and a second current collecting layer to prepare a laminate in which the surface of the first composite layer has a convex shape; and stacking the adhesive layer of the first current collecting layer on the first composite layer of the laminate, followed by pressing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2023-080519 Summary of the Invention [Problem to be solved by the invention]

[0005] If the edge portion of the positive electrode active material layer faces the negative electrode active material layer via the solid electrolyte layer, when the solid electrolyte protrudes outward from the positive electrode active material layer, the edge portion of the positive electrode active material layer may break through the solid electrolyte layer, causing a short circuit.

[0006] In view of the above circumstances, the present invention provides an all-solid-state battery with improved yield. [Means for solving the problem]

[0007] The present inventors have conducted extensive research to solve the above problems, and as a result have found that an all-solid-state battery having a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order, and further having an insulating member in contact with the outer periphery of the solid electrolyte layer, wherein at least a portion of the solid electrolyte layer is located in a region (S) surrounded by the positive electrode active material layer and the insulating member, can improve yield, thereby completing the present invention.

[0008] According to the present invention, there are provided the following all-solid-state battery and method for manufacturing the all-solid-state battery.

[0009] [1] a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order; an insulating member in contact with an outer periphery of the solid electrolyte layer; an all-solid-state battery in which at least a portion of the solid electrolyte layer is located in a region (S) surrounded by the positive electrode active material layer and the insulating member; [2] The all-solid-state battery according to [1], wherein the volume of the solid electrolyte layer is 50% or more and 250% or less when the volume of the region (S) is taken as 100%. [3] The all-solid-state battery according to [1] or [2], wherein the insulating member is located on the outer periphery of the surface of the positive electrode active material layer facing the solid electrolyte layer. [4] The all-solid-state battery according to [1] or [2], wherein the insulating member is in contact with an outer surface of the positive electrode active material layer, and the insulating member has a thickness greater than a thickness of the positive electrode active material layer. [5] The all-solid-state battery according to any one of [1] to [4], wherein the area of the surface of the negative electrode active material layer facing the solid electrolyte layer is larger than the area of the surface of the solid electrolyte layer facing the negative electrode active material layer and is smaller than the area surrounded by the outer periphery of the insulating member. [6] The all-solid-state battery according to any one of [1] to [4], wherein the area of the surface of the negative electrode active material layer facing the solid electrolyte layer is within the area of the surface of the solid electrolyte layer facing the negative electrode active material layer. [7] The all-solid-state battery according to any one of [1] to [6], wherein the thickness of the solid electrolyte layer is greater than the thickness of the region (S). [8] The all-solid-state battery according to any one of [1] to [6], wherein the thickness of the solid electrolyte layer is equal to or less than the thickness of the region (S). [9] The all-solid-state battery according to any one of [1] to [8], wherein the negative electrode active material layer contains one or more negative electrode active materials selected from the group consisting of carbon materials, lithium-based metal materials, Si-based materials, and conductive polymer materials.

[10] The all-solid-state battery according to any one of [1] to [9], wherein the solid electrolyte layer contains one or more solid electrolyte materials selected from the group consisting of an oxide-based solid electrolyte material, a sulfide-based solid electrolyte material, a polymer-based solid electrolyte material, and a halogen-based solid electrolyte material.

[11] The all-solid-state battery according to any one of [1] to

[10] , wherein the insulating member includes one or more selected from the group consisting of insulating tape and insulating films.

[12] A manufacturing method for manufacturing the all-solid-state battery according to any one of [1] to

[11] , A method for producing an all-solid-state battery, comprising the step of providing a solid electrolyte layer to the region (S) surrounded by the positive electrode active material layer and the insulating member. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide an all-solid-state battery with improved yield. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic cross-sectional view illustrating an example of an all-solid-state battery according to an embodiment of the present invention. [Figure 2] FIG. 1 is a schematic cross-sectional view illustrating an example of an all-solid-state battery according to an embodiment of the present invention. [Figure 3] FIG. 1 is a schematic cross-sectional view illustrating an example of an all-solid-state battery according to an embodiment of the present invention. [Figure 4]FIG. 1 is a schematic cross-sectional view illustrating an example of an all-solid-state battery according to an embodiment of the present invention. [Figure 5] FIG. 1 is a schematic cross-sectional view illustrating an example of an all-solid-state battery according to an embodiment of the present invention. [Figure 6] FIG. 1 is a schematic cross-sectional view illustrating an example of an all-solid-state battery according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. To avoid complexity, when there are multiple identical components in the same drawing, only one of them may be labeled with a symbol, and not all of them. The drawings are for illustrative purposes only, and the shapes and dimensional ratios of the components in the drawings do not necessarily correspond to the actual products.

[0013] In this embodiment, "A to B" indicating a numerical range means A or more and B or less unless otherwise specified.

[0014] <All-solid-state battery> The all-solid-state battery of this embodiment has a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order, and further has an insulating member in contact with the outer periphery of the solid electrolyte layer, and at least a part of the solid electrolyte layer is located in a region (S) surrounded by the positive electrode active material layer and the insulating member.

[0015] In a conventional method for manufacturing an all-solid-state battery, a laminate of a solid electrolyte layer and a negative electrode active material layer is first prepared, the laminate of the solid electrolyte layer and the negative electrode active material layer is then pressed, and a positive electrode active material layer is further laminated on the laminate to obtain an all-solid-state battery. However, according to the investigations of the present inventors, it has become clear that in this method for manufacturing an all-solid-state battery, when the laminate of the solid electrolyte layer and the negative electrode active material layer is pressed, lithium contained in the negative electrode active material layer enters the solid electrolyte layer, forming a short circuit, which may cause an over-discharge reaction of the positive electrode and reduce the battery performance of the all-solid-state battery.

[0016] On the other hand, a method of obtaining an all-solid-state battery can also be considered, in which a laminate of a solid electrolyte layer and a positive electrode active material layer is first prepared, the laminate of the solid electrolyte layer and the positive electrode active material layer is then pressed, and then a negative electrode active material layer is further laminated on the laminate. However, according to the investigations of the present inventors, in this method of producing an all-solid-state battery, if the edge portion of the positive electrode active material layer faces the negative electrode active material layer via the solid electrolyte layer, when the solid electrolyte protrudes outward from the positive electrode active material layer, the edge portion of the positive electrode active material layer may break through the solid electrolyte layer, causing a short circuit. For these reasons, there was room for improvement in the yield of all-solid-state batteries.

[0017] As a result of studies conducted by the present inventors based on the above findings, it has been found that by providing an insulating member on the outer periphery of the solid electrolyte layer of an all-solid-state battery and configuring the battery so that at least a portion of the solid electrolyte layer is located in a region surrounded by the positive electrode active material layer and the insulating member, even if a laminate of the solid electrolyte layer and the positive electrode active material layer is pressed in the manufacturing process of the all-solid-state battery, the solid electrolyte protrudes outward from the positive electrode active material layer, and the insulating member prevents the edge portion of the positive electrode active material layer from breaking through the solid electrolyte layer, thereby suppressing short circuits.

[0018] As a result of further investigations based on the above findings, the present inventors have found that an all-solid-state battery having a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order, and further having an insulating member in contact with the outer periphery of the solid electrolyte layer, wherein at least a part of the solid electrolyte layer is located in a region (S) surrounded by the positive electrode active material layer and the insulating member, can improve yield, and have completed the present invention.

[0019] FIG. 1 is a schematic cross-sectional view showing an example of the all-solid-state battery according to the present embodiment.

[0020] The all-solid-state battery of this embodiment has a positive electrode active material layer 10, a solid electrolyte layer 20, and a negative electrode active material layer 30 in this order, and further has an insulating member 40 in contact with the outer periphery of the solid electrolyte layer 20, and at least a part of the solid electrolyte layer 20 is located in a region (S) surrounded by the positive electrode active material layer 10 and the insulating member 40.

[0021] In the all-solid-state battery of this embodiment, at least a portion of the solid electrolyte layer 20 is located in the region (S) surrounded by the positive electrode active material layer 10 and the insulating member 40. Therefore, even if the laminate of the solid electrolyte layer 20 and the positive electrode active material layer 10 is pressed in the manufacturing process, the solid electrolyte protrudes outward from the positive electrode active material layer 10, and the insulating member 40 prevents the edge portion of the positive electrode active material layer 10 from breaking through the solid electrolyte layer 20, thereby preventing a short circuit.

[0022] In the all-solid-state battery of this embodiment, the insulating member 40 may be located on the outer periphery of the surface of the positive electrode active material layer 10 on the solid electrolyte layer 20 side. This eliminates the need for the insulating member 40 to cover the outer surface of the positive electrode active material layer 10, thereby reducing the thickness of the insulating member 40. As a result, the effects of reducing the weight and material costs of the all-solid-state battery can be obtained.

[0023] FIG. 2 is a schematic cross-sectional view showing an example of the all-solid-state battery according to this embodiment. In the all-solid-state battery shown in FIG. 2, the insulating member 40 is in contact with the outer surface of the positive electrode active material layer 10, and the thickness of the insulating member 40 is greater than the thickness of the positive electrode active material layer 10.

[0024] 2, the insulating member 40 is in contact with the outer surface of the positive electrode active material layer 10, and the thickness of the insulating member 40 is greater than the thickness of the positive electrode active material layer 10, so that the insulating member 40 covers the outer surface of the positive electrode active material layer 10. This can further improve the insulation, prevent short circuits, and further improve the yield.

[0025] In the all-solid-state battery of this embodiment, the volume of the solid electrolyte layer 20 is preferably 50% or more, more preferably 75% or more, even more preferably 90% or more, even more preferably 93% or more, even more preferably 95% or more, even more preferably 97% or more, and is preferably 250% or less, more preferably 200% or less, even more preferably 150% or less, even more preferably 110% or less, even more preferably 105% or less, even more preferably 103% or less, when the volume of the region (S) is taken as 100%, from the viewpoint of further improving the performance balance among yield, light weight, and cost. When the volume of the solid electrolyte layer 20 is equal to or greater than the above-mentioned lower limit, poor contact between the positive electrode active material layer 10 and the solid electrolyte layer 20 and poor contact between the solid electrolyte layer 20 and the negative electrode active material layer 30 can be suppressed, thereby further improving yield and reducing defective products due to reduced battery performance. On the other hand, when the volume of the solid electrolyte layer 20 is equal to or less than the above-mentioned upper limit, the amount of the solid electrolyte layer 20 used can be reduced, resulting in reduced weight and material costs.

[0026] For these reasons, from the viewpoint of further improving the performance balance of yield, light weight, and cost, the volume of the solid electrolyte layer 20 of the all-solid-state battery of this embodiment is preferably 50% to 250%, more preferably 75% to 200%, even more preferably 90% to 150%, even more preferably 93% to 110%, even more preferably 95% to 105%, and even more preferably 97% to 103%, when the volume of the region (S) is 100%. Other effects of having the volume of the solid electrolyte layer 20 within the above range include making it easier for the thickness of the solid electrolyte layer 20 to be consistent with the thickness of the insulating member 40, and flattening the surface of the solid electrolyte layer 20.

[0027] FIG. 3 is a schematic cross-sectional view showing an example of the all-solid-state battery according to this embodiment. FIG. 3 shows an all-solid-state battery of the present embodiment in which the area of the surface of the negative electrode active material layer 30 on the side of the solid electrolyte layer 20 is larger than the area of the surface of the solid electrolyte layer 20 on the side of the negative electrode active material layer 30 and is smaller than the area surrounded by the outer periphery of the insulating member 40.

[0028] In the all-solid-state battery of this embodiment, when the area of the surface of the negative electrode active material layer 30 facing the solid electrolyte layer 20 is larger than the area of the surface of the solid electrolyte layer 20 facing the negative electrode active material layer 30 and smaller than the area surrounded by the outer periphery of the insulating member 40, the large area of the negative electrode active material layer 30 causes lithium that reaches the edge portions of the negative electrode active material layer 30 during a charging reaction to be dispersed by solid diffusion, thereby suppressing lithium deposition at the edge portions of the negative electrode active material layer 30. This suppresses contact between the deposited lithium and the solid electrolyte layer 20, thereby reducing defective products due to reduced battery performance and further improving yield.

[0029] FIG. 4 is a schematic cross-sectional view showing an example of the all-solid-state battery according to this embodiment. FIG. 4 shows an all-solid-state battery of this embodiment in which the area of the surface of the negative electrode active material layer 30 on the solid electrolyte layer 20 side is within the area of the surface of the solid electrolyte layer 20 on the negative electrode active material layer 30 side.

[0030] In the all-solid-state battery of this embodiment, if the area of the surface of the negative electrode active material layer 30 facing the solid electrolyte layer 20 is within the area of the surface of the solid electrolyte layer 20 facing the negative electrode active material layer 30, the negative electrode active material layer 30 can be prevented from protruding outward from the outer periphery of the insulating member 40 during the manufacturing process, thereby further improving the yield from the viewpoint of reducing defective products due to short circuits. Furthermore, the amount of negative electrode active material layer 30 used can be reduced, resulting in weight reduction and reduced material costs.

[0031] From the viewpoint of further improving the performance balance among yield, light weight, and cost, the area of the surface of the negative electrode active material layer 30 facing the solid electrolyte layer 20 in the all-solid-state battery of this embodiment is preferably 50% to 150%, more preferably 70% to 130%, even more preferably 80% to 120%, and still more preferably 90% to 110%, when the area of the surface of the solid electrolyte layer 20 facing the negative electrode active material layer 30 is taken as 100%. When the area of the surface of the negative electrode active material layer 30 facing the solid electrolyte layer 20 in the all-solid-state battery of this embodiment is within the above range, the yield can be further improved from the viewpoint of reducing defective products due to deterioration of battery performance and defective products due to short circuits.

[0032] In the all-solid-state battery of this embodiment, the surface area of the negative electrode active material layer 30 on the side of the solid electrolyte layer 20 is preferably 95% or less, more preferably 90% or less, even more preferably 85% or less, and even more preferably 80% or less, of the area of the range surrounded by the periphery of the insulating member 40, taken as 100%, from the viewpoint of further improving the performance balance among yield, light weight, and cost. When the area of the range surrounded by the periphery of the insulating member 40 on the side of the solid electrolyte layer 20 of the all-solid-state battery of this embodiment is equal to or less than the above upper limit, the yield can be further improved from the viewpoint of reducing defective products due to short circuits. The lower limit of the area of the negative electrode active material layer 30 on the side of the solid electrolyte layer 20 of the all-solid-state battery of this embodiment is not particularly limited, but may be, for example, 50% or more, or 70% or more, of the area of the range surrounded by the periphery of the insulating member 40, taken as 100%.

[0033] FIG. 5 is a schematic cross-sectional view showing an example of the all-solid-state battery according to this embodiment. FIG. 5 shows an all-solid-state battery of this embodiment in which the thickness of the solid electrolyte layer 20 is greater than the thickness of the region (S).

[0034] In the all-solid-state battery of this embodiment, when the thickness of the solid electrolyte layer 20 is greater than the thickness of the region (S), poor contact between the positive electrode active material layer 10 and the solid electrolyte layer 20 and poor contact between the solid electrolyte layer 20 and the negative electrode active material layer 30 can be suppressed, and therefore, the yield can be further improved from the viewpoint of reducing defective products due to deterioration of battery performance.

[0035] FIG. 6 is a schematic cross-sectional view showing an example of the all-solid-state battery according to this embodiment. FIG. 6 shows an all-solid-state battery of this embodiment in which the thickness of the solid electrolyte layer 20 is equal to or less than the thickness of the region (S).

[0036] In the all-solid-state battery of this embodiment, when the thickness of the solid electrolyte layer 20 is equal to or less than the thickness of the region (S), the amount of the solid electrolyte layer 20 used can be reduced, thereby achieving the effects of reducing weight and material costs.

[0037] From the viewpoint of further improving the performance balance among yield, light weight, and cost, the thickness of the solid electrolyte layer 20 of the all-solid-state battery of this embodiment is preferably 50% to 200%, more preferably 70% to 150%, even more preferably 80% to 120%, and still more preferably 90% to 110%, when the thickness of the region (S) is taken as 100%. When the thickness of the solid electrolyte layer 20 of the all-solid-state battery of this embodiment is within the above range, the amount of solid electrolyte layer 20 used can be reduced while reducing defective products due to deterioration of battery performance.

[0038] <Negative electrode active material layer 30> From the viewpoint of further improving the balance between battery performance and yield, the negative electrode active material layer 30 of this embodiment is preferably made of a carbon material that occludes lithium, such as graphite, amorphous carbon, diamond-like carbon, fullerene, carbon nanotube, or carbon nanohorn; a lithium-based metal material, such as lithium metal or a lithium alloy; Si, SiO, SiO x(0 < x ≤ 2), Si-based materials such as Si-containing composite materials; including one or more negative electrode active materials selected from the group consisting of conductive polymer materials such as polyacene, polyacetylene, polypyrrole, etc., and more preferably including a lithium-based metal material.

[0039] For the all-solid-state battery of this embodiment, since the manufacturing method of pressing the laminate of the solid electrolyte layer 20 and the positive electrode active material layer 10 can be applied first, even if the negative electrode active material layer 30 contains a lithium-based metal material, the lithium contained in the negative electrode active material layer 30 enters the solid electrolyte layer 20, thereby forming a short circuit, and it can be suppressed that an over-discharge reaction of the positive electrode occurs and the battery performance of the all-solid-state battery deteriorates.

[0040] The negative electrode active material layer 30 of this embodiment preferably contains a metal foil, and more preferably contains a metal foil of lithium metal or lithium alloy. The metal foil may be one obtained by further laminating a metal or an alloy on a base metal foil.

[0041] The negative electrode active material layer 30 of this embodiment may optionally contain a binder. Examples of the binder include fluororesins such as polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyvinyl fluoride (PVF); conductive polymers such as polyanilines, polythiophenes, polyacetylenes, polypyrroles; synthetic rubbers such as styrene-butadiene rubber (SBR), butadiene rubber (BR), chloroprene rubber (CR), isoprene rubber (IR), acrylonitrile-butadiene rubber (NBR); polysaccharides such as carboxymethyl cellulose (CMC), xanthan gum, guar gum, pectin, etc. One of these may be used alone, or two or more may be used in combination.

[0042] The negative electrode active material layer 30 of this embodiment may optionally contain a conductive assistant. Examples of the conductive additive include carbon fibers such as carbon nanofibers; carbon blacks such as acetylene black and ketjen black; and carbon materials such as activated carbon, mesoporous carbon, fullerenes, and carbon nanotubes. One of these may be used alone, or two or more may be used in combination.

[0043] The content of the negative electrode active material in the negative electrode active material layer 30 of this embodiment is preferably 70 parts by mass or more and 100 parts by mass or less, more preferably 80 parts by mass or more and 100 parts by mass or less, and even more preferably 90 parts by mass or more and 100 parts by mass or less, when the total amount of the negative electrode active material layer 30 is taken as 100 parts by mass.

[0044] The thickness of the negative electrode active material layer 30 of this embodiment is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less.

[0045] <Solid electrolyte layer 20> From the viewpoint of further improving the balance between battery performance and yield, the solid electrolyte layer 20 of the present embodiment preferably contains one or more solid electrolyte materials selected from the group consisting of oxide-based solid electrolyte materials, sulfide-based solid electrolyte materials, polymer-based solid electrolyte materials, and halogen-based solid electrolyte materials.

[0046] Examples of oxide-based solid electrolyte materials include NASICON-type solid electrolyte materials such as LiTi2(PO4)3, LiZr2(PO4)3, and LiGe2(PO4)3; 0.5+x Li 0.5-3x ) Perovskite-type solid electrolyte materials such as TiO3; Li2O-P2O5 materials, Li2O-P2O5-Li3N materials, etc. These may be used alone or in combination of two or more.

[0047] Examples of sulfide-based solid electrolyte materials include Li2S-P2S5 materials, Li2S-SiS2 materials, Li2S-GeS2 materials, Li2S-Al2S3 materials, Li2S-SiS2-Li3PO4 materials, Li2S-P2S5-GeS2 materials, Li2S-Li2O-P2S5-SiS2 materials, Li2S-GeS2-P2S5-SiS2 materials, Li2S-SnS2-P2S5-SiS2 materials, Li2S-P2S5-Li3N materials, and Li2S 2+X -P4S3 material, Li2S-P2S5-P4S3 material, etc. These may be used alone or in combination of two or more.

[0048] Examples of polymer-based solid electrolyte materials include polyether-based electrolyte materials such as polyethylene oxide, polypropylene oxide, ethylene oxide-propylene copolymer, and dimethylsiloxane-ethylene oxide copolymer; gel polymer electrolyte materials such as polyacrylonitrile, polyvinylidene fluoride, and vinylidene fluoride-hexafluoropropylene polymer; and polymer solid electrolyte materials using hyperbranched polymers. These may be used alone or in combination of two or more.

[0049] Examples of halogen-based solid electrolyte materials include LiTaOCl4, LiNbOCl4, and LiTa 0.9 Nb 0.1 Metal oxyhalide compounds such as OCl4, metal sulfur halide compounds such as Li2S-P2S5-LiI material, Li2S-P2S5-LiBr material, etc. These may be used alone or in combination of two or more.

[0050] The content of the solid electrolyte in the solid electrolyte layer 20 of this embodiment is preferably 80 parts by mass or more and 100 parts by mass or less, and more preferably 90 parts by mass or more and 100 parts by mass or less, when the total amount of the solid electrolyte layer 20 is 100 parts by mass.

[0051] The thickness of the solid electrolyte layer 20 of this embodiment is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less.

[0052] <Cathode active material layer 10> The positive electrode active material layer 10 of this embodiment preferably contains a positive electrode active material. Examples of the positive electrode active material include composite oxides of lithium and transition metals such as lithium-nickel composite oxide, lithium-cobalt composite oxide, lithium-manganese composite oxide, lithium-nickel-manganese composite oxide, lithium-nickel-cobalt composite oxide, lithium-nickel-aluminum composite oxide, lithium-nickel-cobalt-aluminum composite oxide, lithium-nickel-manganese-cobalt composite oxide, lithium-nickel-manganese-aluminum composite oxide, and lithium-nickel-cobalt-manganese-aluminum composite oxide; transition metal sulfides such as TiS2, FeS, and MoS2; MnO, VO5, and VO 13 transition metal oxides such as TiO2, olivine-type lithium phosphate, etc. These may be used alone or in combination of two or more.

[0053] The volume-based median diameter D of the positive electrode active material in the positive electrode active material layer 10 of this embodiment measured by a laser diffraction scattering method 50 is preferably 1 μm or more and 100 μm or less, more preferably 2 μm or more and 50 μm or less.

[0054] The content of the positive electrode active material in the positive electrode active material layer 10 of this embodiment is preferably 70 parts by mass or more and 100 parts by mass or less, more preferably 80 parts by mass or more and 99 parts by mass or less, and even more preferably 90 parts by mass or more and 98 parts by mass or less, when the total amount of the positive electrode active material layer 10 is 100 parts by mass.

[0055] The positive electrode active material layer 10 of this embodiment preferably contains a conductive additive. Examples of the conductive additive include carbon black, natural graphite, artificial graphite, and carbon fibers such as carbon nanotubes. The graphite may be, for example, flake graphite or spherical graphite. These may be used alone or in combination of two or more.

[0056] The content of the conductive additive in the positive electrode active material layer 10 of this embodiment is preferably 0.01 parts by mass or more and 15 parts by mass or less, more preferably 0.1 parts by mass or more and 10 parts by mass or less, and even more preferably 0.5 parts by mass or more and 8 parts by mass or less, when the total amount of the positive electrode active material layer 10 is 100 parts by mass.

[0057] The positive electrode active material layer 10 of this embodiment preferably contains a binder resin. Examples of binder resins include polytetrafluoroethylene (PTFE) and polyvinylidene fluoride (PVDF).

[0058] The content of the binder resin in the positive electrode active material layer 10 of this embodiment is preferably 0.01 parts by mass or more and 15 parts by mass or less, and more preferably 0.1 parts by mass or more and 10 parts by mass or less, when the total amount of the positive electrode active material layer 10 is 100 parts by mass.

[0059] The positive electrode active material layer 10 of this embodiment preferably contains a solid electrolyte. The type of the solid electrolyte is not particularly limited, and the positive electrode active material layer 10 may contain one or more solid electrolyte materials selected from the group consisting of oxide-based solid electrolyte materials, sulfide-based solid electrolyte materials, polymer-based solid electrolyte materials, and halogen-based solid electrolyte materials.

[0060] The content of the solid electrolyte in the positive electrode active material layer 10 of this embodiment is preferably 1 part by mass or more and 50 parts by mass or less, and more preferably 3 parts by mass or more and 30 parts by mass or less, when the total amount of the positive electrode active material layer 10 is 100 parts by mass.

[0061] The density of the positive electrode active material layer 10 of this embodiment is preferably 1.0 g / cm 3 More than 5.0g / cm 3 or less, more preferably 2.0 g / cm3 More than 4.0g / cm 3 The following is the result.

[0062] The thickness of the positive electrode active material layer 10 of this embodiment is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less.

[0063] <Insulating member 40> In order to further improve yield, the insulating member 40 of this embodiment preferably includes one or more types selected from the group consisting of insulating tapes such as vinyl chloride insulating tape, acetate insulating tape, glass fiber insulating tape, and butyl rubber insulating tape; and insulating films including alumina, polyimide, polyester, polypropylene, etc.

[0064] From the viewpoint of further improving yield, the thickness of the insulating member 40 of this embodiment is preferably 1 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less in the aspect of the all-solid-state battery shown in FIG. Moreover, from the viewpoint of further improving yield, the thickness of the insulating member 40 of the present embodiment is preferably 1 μm or more and 300 μm or less, more preferably 5 μm or more and 200 μm or less, and even more preferably 10 μm or more and 160 μm or less in the aspect of the all-solid-state battery shown in FIG.

[0065] <Positive electrode current collector> The all-solid-state battery of this embodiment may further include a positive electrode current collector in a position in contact with the surface of the positive electrode active material layer 10 opposite to the solid electrolyte layer 20 side.

[0066] The positive electrode current collector may be formed of, for example, aluminum, stainless steel, nickel, titanium, or an alloy thereof. The positive electrode current collector may be in the form of, for example, a foil, a flat plate, or a mesh. The thickness of the positive electrode current collector is not particularly limited, but is, for example, 1 μm or more and 50 μm or less.

[0067] <Negative electrode current collector> The all-solid-state battery of this embodiment may further include a negative electrode current collector at a position in contact with the surface of the negative electrode active material layer 30 opposite to the solid electrolyte layer 20 side.

[0068] The negative electrode current collector may be formed of, for example, copper, stainless steel, nickel, titanium, or an alloy thereof. The negative electrode current collector may be in the form of, for example, a foil, a flat plate, or a mesh. The thickness of the negative electrode current collector is not particularly limited, but is, for example, 1 μm or more and 50 μm or less.

[0069] <Manufacturing method for all-solid-state batteries> The manufacturing method for the all-solid-state battery of this embodiment is a manufacturing method for manufacturing the all-solid-state battery of this embodiment, and includes a step of providing a solid electrolyte layer 20 to a region (S) surrounded by the positive electrode active material layer 10 and the insulating member 40.

[0070] The manufacturing method for the all-solid-state battery of this embodiment includes a step of providing the solid electrolyte layer 20 to the region (S). Therefore, even if the laminate of the solid electrolyte layer 20 and the positive electrode active material layer 10 is pressed in a subsequent step, the solid electrolyte protrudes outward from the positive electrode active material layer 10, and the insulating member 40 prevents the edge portion of the positive electrode active material layer 10 from breaking through the solid electrolyte layer 20, thereby preventing a short circuit.

[0071] In the all-solid-state battery of the aspect shown in FIG. 1, the method for producing the all-solid-state battery of this embodiment preferably includes the steps of: a step (A) of providing an insulating member 40 on the outer periphery of one surface of the positive electrode active material layer 10; a step (B) of providing a solid electrolyte layer (20) in a region (S) surrounded by the positive electrode active material layer (10) and the insulating member (40); a step (C) of pressing the laminate of the positive electrode active material layer 10 and the solid electrolyte layer 20; Contains, in this order: This makes it possible to prevent a decrease in the battery performance of the all-solid-state battery due to lithium contained in the negative electrode active material layer 30 penetrating into the solid electrolyte layer 20, and also to prevent a short circuit due to the solid electrolyte protruding outward from the positive electrode active material layer 10 and the edge portion of the positive electrode active material layer 10 breaking through the solid electrolyte layer 20, thereby further improving the yield.

[0072] In the all-solid-state battery of the aspect shown in FIG. 2, the method for producing the all-solid-state battery of this embodiment preferably includes the steps of: a step (A) of providing an insulating member 40 having a thickness greater than that of the positive electrode active material layer 10 at a position in contact with the outer surface of the positive electrode active material layer 10; a step (B) of forming a solid electrolyte layer (20) in a region (S) surrounded by the positive electrode active material layer (10) and the insulating member (40); a step (C) of pressing the laminate of the positive electrode active material layer 10 and the solid electrolyte layer 20; Contains, in this order: This makes it possible to prevent a decrease in the battery performance of the all-solid-state battery due to lithium contained in the negative electrode active material layer 30 penetrating into the solid electrolyte layer 20, and also to prevent a short circuit due to the solid electrolyte protruding outward from the positive electrode active material layer 10 and the edge portion of the positive electrode active material layer 10 breaking through the solid electrolyte layer 20, thereby further improving the yield.

[0073] The method for producing the all-solid-state battery of this embodiment may further include a step (D) of laminating the negative electrode active material layer 30 on the laminate of the positive electrode active material layer 10 and the solid electrolyte layer 20. From the viewpoint of further improving the yield, the step (D) is preferably carried out after the step (C).

[0074] Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various other configurations can be adopted. Furthermore, the present invention is not limited to the above-described embodiments, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention. [Explanation of symbols]

[0075] 10 Cathode active material layer 20 Solid electrolyte layer 30 Negative electrode active material layer 40 Insulating material

Claims

1. a positive electrode active material layer, a solid electrolyte layer, and a negative electrode active material layer in this order; an insulating member in contact with an outer periphery of the solid electrolyte layer; an all-solid-state battery in which at least a portion of the solid electrolyte layer is located in a region (S) surrounded by the positive electrode active material layer and the insulating member;

2. 2. The all-solid-state battery according to claim 1, wherein the volume of the solid electrolyte layer is 50% or more and 250% or less when the volume of the region (S) is taken as 100%.

3. The all-solid-state battery according to claim 1 , wherein the insulating member is located on an outer periphery of a surface of the positive electrode active material layer facing the solid electrolyte layer.

4. 3. The all-solid-state battery according to claim 1, wherein the insulating member is in contact with an outer surface of the positive electrode active material layer, and the insulating member has a thickness greater than a thickness of the positive electrode active material layer.

5. 5. The all-solid-state battery according to claim 1, wherein an area of a surface of the negative electrode active material layer facing the solid electrolyte layer is larger than an area of a surface of the solid electrolyte layer facing the negative electrode active material layer and smaller than an area surrounded by an outer periphery of the insulating member.

6. 5. The all-solid-state battery according to claim 1, wherein the area of the surface of the negative electrode active material layer facing the solid electrolyte layer is within the area of the surface of the solid electrolyte layer facing the negative electrode active material layer.

7. The all-solid-state battery according to any one of claims 1 to 6, wherein the thickness of the solid electrolyte layer is greater than the thickness of the region (S).

8. The all-solid-state battery according to any one of claims 1 to 6, wherein the thickness of the solid electrolyte layer is equal to or less than the thickness of the region (S).

9. The all-solid-state battery according to any one of claims 1 to 8, wherein the negative electrode active material layer contains one or more negative electrode active materials selected from the group consisting of carbon materials, lithium-based metal materials, Si-based materials, and conductive polymer materials.

10. 10. The all-solid-state battery according to claim 1, wherein the solid electrolyte layer comprises one or more solid electrolyte materials selected from the group consisting of an oxide-based solid electrolyte material, a sulfide-based solid electrolyte material, a polymer-based solid electrolyte material, and a halogen-based solid electrolyte material.

11. The all-solid-state battery according to any one of claims 1 to 10, wherein the insulating member comprises one or more selected from the group consisting of insulating tape and insulating films.

12. A manufacturing method for manufacturing the all-solid-state battery according to any one of claims 1 to 11, a step of providing a solid electrolyte layer to the region (S) surrounded by the positive electrode active material layer and the insulating member.

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