solid-state batteries

Abstract

To provide a solid-state battery in which cracks are less likely to occur in the solid electrolyte layer. [Solution] A solid-state battery comprising: a laminate in which a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector are stacked in this order; an outer casing housing the laminate; and a block body in contact with the side surfaces of the positive electrode active material layer and / or the negative electrode active material layer and fixed to the outer casing and / or the laminate, wherein the Young's modulus of at least the portion of the block body in contact with the side surfaces of the positive electrode active material layer and / or the negative electrode active material layer is 50 GPa or more, and both ends of the block body are separated from the positive electrode current collector and the negative electrode current collector in the stacking direction of the laminate.

Description

Technical Field

[0001] This disclosure relates to a solid-state battery.

Background Art

[0002] A secondary battery in which the periphery of a battery element is coated with resin and a secondary battery in which a spacer contacting the battery element is disposed are known. For example, Patent Document 1 discloses a solid-state battery in which the side surface of a laminated battery is coated with resin. For example, Patent Document 2 discloses a power storage element in which a spacer having a regulating portion that abuts against a part of a current collector and regulates movement in the longitudinal direction is disposed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] The active material of a solid-state battery repeats expansion and contraction with charge and discharge, and volume fluctuations in the active material layer may cause cracks in the solid electrolyte layer.

[0005] This disclosure has been made under the above circumstances. An object of this disclosure is to provide a solid-state battery in which cracks are less likely to occur in the solid electrolyte layer.

Means for Solving the Problems

[0006] Specific means for solving the above problems include the following aspects. <1> A laminate in which a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector are laminated in this order, An exterior body that houses the laminate inside, It comprises a block body that is in contact with the side surface of the positive electrode active material layer and / or the negative electrode active material layer and is fixed to the outer casing and / or the laminate, The Young's modulus of at least the portion of the block body in contact with the side surface of the positive electrode active material layer and / or the negative electrode active material layer is 50 GPa or more. In the stacking direction of the laminate, both ends of the block body are separated from the positive electrode current collector and the negative electrode current collector. solid state battery. <2> The block body is fixed to the exterior body. <1> Solid-state batteries as described above. <3> The bending strength of at least the portion of the block body in contact with the side surface of the positive electrode active material layer and / or the negative electrode active material layer is 500 MPa or more. <1> or <2> Solid-state batteries as described above. <4> The positive electrode active material layer contains S element, In a direction perpendicular to the stacking direction of the laminate, the solid electrolyte layer extends further than the positive electrode active material layer. The block body is in contact with the side surface of the positive electrode active material layer and one main surface and side surface of the solid electrolyte layer, and the block body has an L-shape in a cross-section in the stacking direction of the laminate. <1> ~ <3> A solid-state battery as described in any one of the items. <5> The block body comprises a first block body in contact with the side surface of the positive electrode active material layer, and a second block body in contact with the first block body and the solid electrolyte layer. The Young's modulus of the second block body is lower than that of the first block body. <1> ~ <4> A solid-state battery as described in any one of the items. [Effects of the Invention]

[0007] According to this disclosure, a solid-state battery is provided in which cracks are less likely to occur in the solid electrolyte layer. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic cross-sectional view showing an example of the configuration of the solid-state battery of this disclosure. [Figure 2] It is a schematic cross-sectional view showing another configuration example of the solid-state battery of the present disclosure. [Figure 3] It is a schematic cross-sectional view showing another configuration example of the solid-state battery of the present disclosure. [Figure 4] It is a schematic cross-sectional view showing another configuration example of the solid-state battery of the present disclosure.

Embodiments for Carrying out the Invention

[0009] Hereinafter, embodiments of the present disclosure will be described. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the embodiments.

[0010] In the present disclosure, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved.

[0011] In the present disclosure, "A and / or B" is synonymous with "at least one of A and B". That is, "A and / or B" means that it may be only A, only B, or a combination of A and B.

[0012] In the present disclosure, the numerical range indicated by using "~" indicates a range including the numerical values described before and after "~" as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0013] In the present disclosure, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the multiple substances present in the composition.

[0014] <Solid-state battery> The solid-state batteries of the present disclosure include so-called all-solid-state batteries that use a solid electrolyte as the electrolyte. In the solid-state batteries of the present disclosure, the solid electrolyte may contain less than 10% by mass of an electrolytic solution with respect to the total amount of the electrolyte, and may be a composite solid electrolyte containing an inorganic solid electrolyte and a polymer electrolyte.

[0015] The solid-state battery of the present disclosure includes a laminate in which a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector are laminated in this order, an exterior body that houses the laminate inside, and a block body that contacts the side surfaces of the positive electrode active material layer and / or the negative electrode active material layer and is fixed to the exterior body and / or the laminate. The Young's modulus of at least the portion of the block body that contacts the side surfaces of the positive electrode active material layer and / or the negative electrode active material layer is 50 GPa or more. And both ends of the block body are separated from the positive electrode current collector and the negative electrode current collector in the stacking direction of the laminate.

[0016] In the present disclosure, the fixation of members means that the members do not shift in position. Fixation is realized, for example, by pressure contact between members, tightening of members, adhesion with resin, or the like.

[0017] In the solid-state battery of the present disclosure, cracks are unlikely to occur in the solid electrolyte layer. The mechanism is speculated as follows. Since the block body contacts the side surface of the active material layer, there is no space for the active material layer to expand in the length direction. And the block body is fixed to the exterior body and / or the laminate, and is a member with a Young's modulus of at least 50 GPa for at least the portion that contacts the side surface of the active material layer and is difficult to deform. Therefore, the volume change of the active material layer is suppressed, and cracks in the solid electrolyte layer caused by the volume change of the active material layer are unlikely to occur.

[0018] In the solid-state battery of this disclosure, the functionality and safety of the solid-state battery are ensured by the fact that both ends of the block body are separated from the positive electrode current collector and the negative electrode current collector in the stacking direction of the laminate. This is because the block body does not damage the current collector, nor does the block body interfere with the connection between the current collector and the electrode tab. Furthermore, the restraining pressure applied in the stacking direction of the laminate by the outer material, etc., is reliably applied to the laminate. In addition, because there is a space between the block body and the current collector where internal pressure is released, there is little risk of the battery rupturing when the battery expands.

[0019] The Young's modulus of a block body is an indicator of its resistance to deformation. The Young's modulus of at least the portion of the block body in contact with the sides of the positive electrode active material layer and / or negative electrode active material layer is 50 GPa or higher, preferably 70 GPa or higher, more preferably 100 GPa or higher, even more preferably 150 GPa or higher, even more preferably 200 GPa or higher, and even more preferably 250 GPa or higher, from the viewpoint of suppressing expansion of the active material layer. There is no upper limit to the Young's modulus of the block body, but for example, it should be 1000 GPa or lower.

[0020] From the viewpoint of suppressing the expansion of the active material layer, the block body preferably has a bending strength of 500 MPa or more in the portion in contact with at least the side surface of the positive electrode active material layer and / or the negative electrode active material layer, more preferably 550 MPa or more, and even more preferably 600 MPa or more. The inventors conducted simulations of a solid-state battery and found that when the positive electrode active material layer is stretched to its maximum extent in a direction perpendicular to the stacking direction, a force equivalent to a bending strength of 500 MPa is applied to the block body that is positioned to cover the outer circumference of the positive electrode active material layer. Therefore, it is preferable that the block body has the above-mentioned bending strength. There is no upper limit on the bending strength of the block material, but for example, it should be 1200 MPa or less.

[0021] A block body is a component made of an insulating and electrochemically stable material. A block body may be a single component or a component made up of multiple components (for example, two or three components combined).

[0022] The method for measuring the Young's modulus and flexural strength of a block body is as follows. The test specimen is prepared from the same material as the actual block. The thickness direction of the test specimen is the same as the thickness direction of the actual block (the lamination direction of the laminate). The length direction of the test specimen is the same as the length direction of the actual block (the direction perpendicular to the lamination direction of the laminate). If the block consists of multiple components, a test specimen is prepared for each component. For materials such as ceramics, the Young's modulus (GPa) of the block is measured by a three-point bending test in accordance with JIS R1602 "Test Method for Elastic Modulus of Fine Ceramics". The bending strength (MPa) of the block is measured by a three-point bending test in accordance with JIS R1601 "Test Method for Room Temperature Bending Strength of Fine Ceramics". If the material is resin, the Young's modulus (GPa) (tensile modulus) is measured according to JIS K7161 "Plastics - Method for determining tensile properties". The bending strength (MPa) is measured according to JIS K7171 "Plastics - Method for determining bending properties". All tests will be conducted in an environment with a temperature of 23°C and a relative humidity of 50%.

[0023] In one embodiment of the solid-state battery of this disclosure, a block body is in contact with the side surface of the positive electrode active material layer, and the Young's modulus of at least the portion of the block body in contact with the side surface of the positive electrode active material layer is 50 GPa or more. Since the positive electrode active material layer tends to undergo volume fluctuations, the block body is placed in contact with the positive electrode active material layer.

[0024] In one embodiment of the solid-state battery of this disclosure, the block body is fixed to the outer casing. The force with which the outer casing tightens the block body and the laminate acts as a reaction force against the expansion of the active material layer, and the expansion of the active material layer can be suppressed more effectively compared to a configuration in which the block body is fixed to the laminate.

[0025] The configuration of the solid-state battery of this disclosure will be described with reference to Figures 1 to 4. Figures 1 to 4 are schematic cross-sectional views of an embodiment of the solid-state battery, and are cross-sections parallel to the stacking direction of the laminate. Figures 1 to 4 are schematic cross-sectional views for explaining the position of the components, and the structure of each component is abstracted or simplified. The sizes of the components in the drawings are conceptual, and the relative relationships of the sizes between components are not limited thereto. In Figures 1 to 4, components having similar functions are denoted by the same reference numerals and described accordingly.

[0026] Solid-state batteries 101 to 104 each have a laminate 40 in which a positive electrode current collector 31, a positive electrode active material layer 21, a solid electrolyte layer 11, a metal interface layer 12, a negative electrode active material layer 22, and a negative electrode current collector 32 are stacked in this order, a block body 50, an outer casing 60, a positive electrode tab 71, and a negative electrode tab 72. The block body 50 of solid-state batteries 102 and 104 consists of a first block body 51 and a second block body 52. ​​The metal interface layer 12 is a layer provided in one example of the embodiment and may be omitted.

[0027] Solid-state batteries 101 to 104 comprise a laminate 40 in which a positive electrode current collector 31, a positive electrode active material layer 21, a solid electrolyte layer 11, a negative electrode active material layer 22, and a negative electrode current collector 32 are stacked one layer at a time. The solid-state batteries of this disclosure are not limited to the above embodiment. For example, the solid-state batteries of this disclosure may also comprise a laminate in which a positive electrode current collector 31, a positive electrode active material layer 21, a solid electrolyte layer 11, a negative electrode active material layer 22, a negative electrode current collector 32, a negative electrode active material layer 22, a solid electrolyte layer 11, a positive electrode active material layer 21, and a positive electrode current collector 31 are stacked in this order.

[0028] In solid-state batteries 101 to 104, the outer casing 60 is pressed against the block body 50. This fixes the block body 50 to the outer casing 60 and the laminated body 40.

[0029] In solid batteries 101 and 102, the solid electrolyte layer 11 extends beyond the positive electrode active material layer 21 in a direction perpendicular to the stacking direction of the laminate 40, and the block body 50 is in contact with the side surface of the positive electrode active material layer 21 and one main surface and side surface of the solid electrolyte layer 11. In solid batteries 101 and 102, the block body 50 has an L-shape in the cross-section of the laminate 40 in the stacking direction. The block body 50 in this embodiment is relatively easy to place inside the battery because its arrangement is stable, and it more effectively suppresses the expansion of the positive electrode active material layer 21.

[0030] In solid batteries 103 and 104, the length of each layer of the laminate 40 is the same in a direction perpendicular to the stacking direction of the laminate 40, and the block body 50 is in contact with the side surface of the positive electrode active material layer 21, the side surface of the solid electrolyte layer 11, and the side surface of the negative electrode active material layer 22. In solid batteries 103 and 104, the block body 50 has a rectangular shape in a cross-section in the stacking direction of the laminate 40.

[0031] Lines e1 and e2 indicate the positions of the upper surface (the side facing the positive electrode current collector 31) and lower surface (the side facing the negative electrode current collector 32) of the block body 50 in the stacking direction of the laminate 40, respectively. Lines f1 and f2 indicate the positions of the lower surface (the side facing the block body 50) of the positive electrode current collector 31 and the upper surface (the side facing the block body 50) of the negative electrode current collector 32 in the stacking direction of the laminate 40, respectively. Lines e1 and f1 are separated, and lines e2 and f2 are separated. That is, in the stacking direction of the laminate 40, both ends of the block body 50 are separated from the positive electrode current collector 31 and the negative electrode current collector 32.

[0032] The solid-state batteries 102 and 104 each have a block body 50 comprising a first block body 51 in contact with the side surface of the positive electrode active material layer 21, and a second block body 52 in contact with the first block body 51 and the solid electrolyte layer 11. The first block body 51 and the second block body 52 may be made of the same material or of different materials. The Young's modulus and / or flexural strength of the first block body 51 and the second block body 52 may be the same or different values.

[0033] The first block body 51 has a Young's modulus of 50 GPa or more, preferably 70 GPa or more, more preferably 100 GPa or more, even more preferably 150 GPa or more, even more preferably 200 GPa or more, and even more preferably 250 GPa or more, from the viewpoint of suppressing the expansion of the positive electrode active material layer 21. The bending strength of the first block body 51 is preferably 500 MPa or more, more preferably 550 MPa or more, and even more preferably 600 MPa or more. Examples of the first block body 51 include members made of ceramics (including fine ceramics), artificial quartz, quartz glass, borosilicate glass, etc.

[0034] The second block body 52 is preferably a member that is not too rigid, from the viewpoint of preventing damage to the outer casing 60 and the laminate 40. Therefore, the Young's modulus of the second block body 52 is preferably lower than that of the first block body 51, preferably less than 50 GPa, more preferably 30 GPa or less, and even more preferably 10 GPa or less. The bending strength of the second block body 52 is preferably 300 MPa or less, more preferably 200 MPa or less, and even more preferably 150 MPa or less. Examples of the second block body include members made of resin.

[0035] The following describes in detail each layer and outer casing that make up the laminate. In the following description, symbols will be omitted.

[0036] [Positive electrode current collector] The shape of the positive electrode current collector can be, for example, foil-like or mesh-like. Examples of materials for the positive electrode current collector include stainless steel, aluminum, nickel, iron, titanium, and carbon. Aluminum alloy foil or aluminum foil is preferred as the positive electrode current collector.

[0037] [Cathode active material layer] The positive electrode active material layer contains a positive electrode active material. The positive electrode active material layer may optionally contain at least one of a positive electrode solid electrolyte, a conductive additive, and a binder. Any known positive electrode active material layer is applicable as the positive electrode active material layer.

[0038] As an example of an embodiment of the positive electrode active material layer, there is a layer containing a positive electrode active material having S element, a sulfur-containing compound having P element and S element, and a conductive additive, but substantially free of Li element. The positive electrode composite material described in Japanese Patent Application Publication No. 2019-212615 can be applied to this embodiment. The above-described positive electrode active material layer has low irreversible capacity and is resistant to capacity degradation. By applying the above-described positive electrode active material layer to the solid-state battery of this disclosure, the reliability of the solid-state battery can be further improved.

[0039] The element S is preferably elemental sulfur, specifically S8 sulfur. S8 sulfur may be in any of the crystalline forms of α-sulfur, β-sulfur, or γ-sulfur.

[0040] The sulfur-containing compound preferably contains a PS4 structure, which is an ortho-structure of element P. The sulfur-containing compound may also contain an ortho-structure of element M (where M is, for example, Ge, Sn, Si, B, or Al). Examples of ortho-structures of element M include GeS4, SnS4, SiS4, BS3, and AlS3 structures. The sulfur-containing compound may also contain a sulfide of element P (for example, P2S5).

[0041] Examples of conductive additives include carbon materials, metallic materials, and conductive polymer materials. Examples of carbon materials include carbon black (e.g., acetylene black, furnace black, Ketjen black, etc.), fibrous carbon (e.g., vapor-processed carbon fibers, carbon nanotubes, carbon nanofibers, etc.), graphite, and carbon fluoride. Examples of metallic materials include metal powders (e.g., aluminum powder, etc.), conductive whiskers (e.g., zinc oxide, potassium titanate, etc.), and conductive metal oxides (e.g., titanium oxide, etc.). Examples of conductive polymer materials include polyaniline, polypyrrole, and polythiophene. Conductive additives may be used individually or in mixtures of two or more types.

[0042] Examples of binders include vinyl halide resins, rubbers, and polyolefin resins. Other components include oxide solid electrolytes, halide solid electrolytes, thickeners, surfactants, dispersants, wetting agents, defoamers, and solvents.

[0043] [Negative electrode current collector] The shape of the negative electrode current collector can be, for example, foil-like or mesh-like. Examples of materials for the negative electrode current collector include stainless steel, aluminum, copper, nickel, iron, titanium, and carbon. Copper foil or nickel foil is preferred as the negative electrode current collector.

[0044] [Negative electrode active material layer] The negative electrode active material layer contains a negative electrode active material. The negative electrode active material layer may optionally contain at least one of a negative electrode solid electrolyte, a conductive additive, and a binder. Any known negative electrode active material layer is applicable as the negative electrode active material layer.

[0045] Examples of negative electrode active materials include Li-based active materials such as metallic lithium, carbon-based active materials such as graphite, oxide-based active materials such as lithium titanate, and Si-based active materials such as elemental Si.

[0046] Examples of embodiments of the negative electrode active material layer include metallic Li foil and Li-X alloy foil (where X is, for example, Mg, Ag, In, Sn, Si, Ga, Au, or Pt). The proportion of X is, for example, 1% to 20% by mass.

[0047] [Solid electrolyte layer] The solid electrolyte layer contains a solid electrolyte. The solid electrolyte may contain less than 10% by mass of electrolyte relative to the total amount of electrolyte. The solid electrolyte may also be a composite solid electrolyte containing an inorganic solid electrolyte and a polymer electrolyte.

[0048] The solid electrolyte preferably includes one selected from the group consisting of sulfide solid electrolytes, oxide solid electrolytes, and halide solid electrolytes. The sulfide solid electrolyte preferably contains sulfur (S) as the main component of the anionic element, and further contains, for example, Li and A. Element A is at least one selected from the group consisting of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In. The oxide solid electrolyte contains oxygen (O) as the main component of the anionic element, and may also contain, for example, Li and Q elements. The Q element is at least one selected from the group consisting of Nb, B, Al, Si, P, Ti, Zr, Mo, W, and S. A suitable halide solid electrolyte is one containing Li, M, and X (where M represents at least one of Ti, Al, and Y, and X represents F, Cl, or Br).

[0049] The solid electrolyte layer may or may not contain a binder. Examples of binders that may be included in the solid electrolyte layer include halogenated vinyl resins, rubbers, and polyolefin resins. Examples of halogenated vinyl resins include polyvinylidene fluoride (PVdF) and copolymers of polyvinylidene fluoride and hexafluoropropylene (PVdF-HFP). Examples of polyolefin resins include butadiene rubber (BR), acrylate butadiene rubber (ABR), styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), and butyl rubber (isobutylene-isoprene rubber). Examples of polyolefin resins include polyethylene and polypropylene. The binder may be a diene-based rubber containing a double bond in the main chain, for example, a butadiene-based rubber in which butadiene accounts for 30 mol% or more of the total.

[0050] [Metal interface layer] A metal interface layer may be present between the solid electrolyte layer and the negative electrode active material layer. The metal interface layer may be, for example, a metal vapor-deposited film such as In, Sn, or an In-Sn alloy.

[0051] [Exterior] Examples of outer packaging include aluminum laminate film packs and metal cans.

[0052] [Manufacturing method for solid-state batteries] The solid-state battery of this disclosure is manufactured, for example, by the following steps 1 to 3. The first step is to manufacture a laminate by stacking a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector in that order. A metal interface layer may be stacked between the solid electrolyte layer and the negative electrode active material layer. The second step is to arrange block bodies around the laminated body. The third step involves arranging the positive electrode tab and negative electrode tab, housing them in the outer casing, and vacuum sealing them.

[0053] The shape and applications of the solid-state batteries of this disclosure are not limited. The solid-state batteries of this disclosure can be applied, for example, to HEVs (Hybrid Electric Vehicles), PHEVs (Plug-in Hybrid Electric Vehicles), and BEVs (Battery Electric Vehicles). [Examples]

[0054] The solid-state battery of this disclosure will be described in more detail below with reference to examples. The materials, dimensions, combinations, etc., shown in the following examples can be modified as appropriate without departing from the spirit of this disclosure. Therefore, the solid-state battery of this disclosure should not be interpreted restrictively by the specific examples shown below.

[0055] In the following descriptions, synthesis, processing, and manufacturing were carried out at room temperature (25°C ± 3°C) unless otherwise specified.

[0056] <Preparation of experimental cells> [Cell structure] • Laminate: Roughened Al foil / S-P2S5-C composite layer / Sulfide solid electrolyte / Sn layer / Li-10 mass% Mg alloy foil / Roughened Ni foil • Block letters: The materials and dimensions for each type from Type 1 to Type 4 are as described below. • Positive electrode tab: Al foil • Negative electrode tab: Ni foil • Laminating film: Aluminum laminating film

[0057] [Fabrication of the positive electrode] S (80°C vacuum-dried), P2S5, and single-walled carbon nanotubes (120°C vacuum-dried) were mixed in a mortar in a mass ratio of 42:35:23. 1.7 g of the mixture and 80 g of 4 mm diameter zirconia balls were placed in each ball mill pot, and planetary ball milling was performed at 400 rpm for a total of 36 hours. After ball milling, the mixture was classified dry using a 38 μm sieve to obtain a sulfur cathode composite. A cathode slurry was prepared using mesitylene as the solvent, with a sulfur cathode composite to binder mass ratio of 99.7:0.3. The cathode slurry was coated onto roughened aluminum foil with a coating gap of 220 μm, then pre-dried at 50°C and fully dried at 100°C for 30 minutes to obtain the cathode (cathode current collector and cathode active material layer). The cathode was punched out into a circle of a predetermined diameter.

[0058] [Preparation of a solid electrolyte layer] A solid electrolyte slurry was prepared using heptane as the solvent, with a solid electrolyte (median diameter 0.5 μm) and binder mass ratio of 90.9:9.1. The solid electrolyte slurry was coated onto a release film with a coating gap of 450 μm, then pre-dried at room temperature for about 3 hours, and fully dried at 165°C for 1 hour to obtain a solid electrolyte layer. The solid electrolyte layer with the release film attached was punched out into a circle of a predetermined diameter, and the two coated surfaces were stacked and pressed at room temperature with a force of 6t. After pressing, the release film was peeled off to obtain a self-supporting solid electrolyte layer. Next, a metal interface layer (Sn layer, thickness 0.1 μm) was deposited on one side of the self-supporting solid electrolyte layer by sputtering.

[0059] [Fabrication of the negative electrode] A Li-10 mass%Mg alloy foil (100 μm thick) was punched out into a circle of a predetermined diameter. A roughened Ni foil was punched out into a circle of a predetermined diameter. The Li-10 mass%Mg alloy foil and the roughened Ni foil were bonded together with a thickness of 0.1t to obtain a negative electrode (negative electrode current collector and negative electrode active material layer).

[0060] [Preparation of laminated cells] A laminate was formed by stacking the negative electrode, a self-supporting solid electrolyte layer, and a positive electrode in that order. Block bodies were placed around the laminate during this process. Next, the positive electrode tab and negative electrode tab were placed, and the laminate was vacuum-sealed within a laminate film. The sealed cell was isotropically pressed at 300 MPa by CIP (Cold Isostatic Pressing) to obtain a laminate cell.

[0061] Experimental cells of types 1 to 4 were fabricated using the above process. The dimensions of each type are as follows.

[0062] [Type 1] Type 1 has the form shown in the schematic diagram in Figure 2. The diameter of each layer is the diameter of the punched circle. The thickness of each layer is the thickness of each layer during manufacturing. ·Positive electrode current collector: diameter 11.28mm ·Cathode active material layer: diameter 11.28mm, layer thickness 60μm ·Solid electrolyte layer: diameter 14.50mm, layer thickness 75μm ·Metal interface layer: diameter 14.50mm, layer thickness 0.1μm ·Negative electrode active material layer: diameter 13.00mm, layer thickness 100μm ·Negative electrode current collector: diameter 14.50mm • First block: A component with a 30mm x 30mm rectangular plate and a hole with an inner diameter of 11.28mm, with a thickness of 40μm. The material is PEEK resin, high-strength alumina, or sapphire. • Second block: A 30mm x 30mm rectangular plate with a hole having an inner diameter of 15.10mm, and a thickness of 135μm. The material is the same as the first block. (Considering that the solid electrolyte layer will elongate in a direction perpendicular to the stacking direction during cell fabrication, the inner diameter of the second block was made slightly larger than the diameter of 14.50mm.) The first block was positioned so as to be in contact with the lower side of the positive electrode active material layer (the side closer to the solid electrolyte layer) and one of the main surfaces of the solid electrolyte layer. The second block was positioned so as to be in contact with the bottom surface of the first block (the surface facing the solid electrolyte layer) and the side of the solid electrolyte layer.

[0063] [Type 2] Type 2 has the form shown in the schematic diagram in Figure 3. The diameter of each layer is the diameter of the punched circle. The thickness of each layer is the thickness of each layer during manufacturing. ·Positive electrode current collector: diameter 11.28mm ·Cathode active material layer: diameter 11.28mm, layer thickness 60μm ·Solid electrolyte layer: diameter 11.28mm, layer thickness 75μm ·Metal interface layer: diameter 11.28mm, layer thickness 0.1μm ·Negative electrode active material layer: diameter 11.28mm, layer thickness 100μm ·Negative electrode current collector: diameter 11.28mm • Block body: A component consisting of a 30mm x 30mm rectangular plate with an inner diameter of 11.28mm and a thickness of 210μm. The material is PEEK resin, high-strength alumina, or sapphire. The block was positioned so as to be in contact with the lower side of the positive electrode active material layer (the side closer to the solid electrolyte layer), the side of the solid electrolyte layer, and the upper side of the negative electrode active material layer (the side closer to the solid electrolyte layer).

[0064] [Type 3] Type 3 has the schematic configuration shown in Figure 2. The experimental cell was fabricated in the same manner as the experimental cell of Type 1, except that the material of the second block body was entirely made of PEEK resin.

[0065] [Type 4] Type 4 has the form shown in the schematic diagram in Figure 4. The experimental cell was prepared in the same manner as the experimental cell of Type 2, except that the block body was modified as described below. • First block: A component with a 20mm x 20mm rectangular plate and a hole with an inner diameter of 11.28mm, with a thickness of 40μm. The material is PEEK resin, high-strength alumina, or sapphire. • Second block: A 30mm x 30mm rectangular plate with a hole of inner diameter 11.28mm, 210μm thick, and a stepped section (inner dimensions 20mm x 20mm, height 40μm) on the upper inner surface into which the first block fits. Material: PEEK resin. The first block was fitted into the stepped portion of the second block, and the block was positioned so that it was in contact with the lower side of the positive electrode active material layer (the side closer to the solid electrolyte layer), the side of the solid electrolyte layer, and the upper side of the negative electrode active material layer (the side closer to the solid electrolyte layer).

[0066] <Performance Evaluation> [Initial cycle trial] With a cutoff voltage in the range of 3.1V-1.2V, it has a constant current density of 0.584mA / cm². 2 (1C = 5.84mA / cm 2 A temperature equivalent to 0.1C was applied to the cell, and the first cycle test was performed at 60°C. The presence or absence of cracks in the solid electrolyte layer during the initial expansion of the positive electrode was checked. The results for Type 1 and Type 2 are shown in Table 1, and the results for Type 3 and Type 4 are shown in Table 2.

[0067] [Table 1]

[0068] [Table 2] [Explanation of symbols]

[0069] 101, 102, 103, 104 Solid state battery 11 Solid electrolyte layer 12 Metal interface layer 21 Cathode active material layer 22 Negative electrode active material layer 31 Positive electrode current collector 32 Negative electrode current collector 40-layer structure 50 block letters 51. Block 1 52. Second Block 60 Exterior 71 Positive Tab 72 Negative Electrode Tabs

Claims

1. A laminate in which a positive electrode current collector, a positive electrode active material layer, a solid electrolyte layer, a negative electrode active material layer, and a negative electrode current collector are stacked in this order, An outer casing that houses the aforementioned laminate inside, It comprises a block body that is in contact with the side surface of the positive electrode active material layer and / or the negative electrode active material layer and fixed to the outer casing and / or the laminate, The Young's modulus of at least the portion of the block body in contact with the side surface of the positive electrode active material layer and / or the negative electrode active material layer is 50 GPa or more. In the stacking direction of the laminate, both ends of the block body are separated from the positive electrode current collector and the negative electrode current collector. solid state battery.

2. The solid battery according to claim 1, wherein the block body is fixed to the outer casing.

3. The solid battery according to claim 1, wherein the bending strength of at least the portion of the block body in contact with the side surface of the positive electrode active material layer and / or the negative electrode active material layer is 500 MPa or more.

4. The positive electrode active material layer contains S element, In a direction perpendicular to the stacking direction of the laminate, the solid electrolyte layer extends further than the positive electrode active material layer. The block body is in contact with the side surface of the positive electrode active material layer and one main surface and side surface of the solid electrolyte layer, and the block body has an L-shape in a cross-section in the stacking direction of the laminate. The solid-state battery according to claim 1.

5. The block body comprises a first block body in contact with the side surface of the positive electrode active material layer, and a second block body in contact with the first block body and the solid electrolyte layer. The Young's modulus of the second block body is lower than that of the first block body. A solid-state battery according to any one of claims 1 to 4.

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