Solid-state battery

Abstract

The invention discloses a solid-state battery. This solid-state battery is provided with: 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; the Young's modulus of at least a portion of the block in contact with a side surface 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 are separated from the positive electrode current collector and the negative electrode current collector in a lamination direction of the laminate.

Description

Technical Field

[0001] This disclosure relates to solid-state batteries. Background Technology

[0002] Secondary batteries with resin-coated battery elements surrounding them and secondary batteries with spacers arranged in contact with the battery elements are known. For example, Japanese Patent Application Laid-Open No. 2017-220447 discloses a solid battery with resin-coated laminated battery sides. For example, Japanese Patent Application Laid-Open No. 2015-156366 discloses an energy storage element with spacers having a limiting portion that contacts a portion of a current collector and restricts movement in the longitudinal direction. Summary of the Invention

[0003] When the active material of a solid-state battery repeatedly expands and contracts during charging and discharging, the volume change of the active material layer may cause cracks (ruptures) in the solid electrolyte layer.

[0004] This disclosure is made in light of the above circumstances.

[0005] The subject of this disclosure is to provide a solid-state battery in which the solid electrolyte layer is less prone to cracking.

[0006] The specific means to solve the above problems include the following solutions.

[0007] <1> A solid-state battery comprising a stack, an outer casing, and a bulk component.

[0008] The laminate is composed of a positive current collector, a positive active material layer, a solid electrolyte layer, a negative active material layer, and a negative current collector stacked in this order.

[0009] The outer casing internally houses the stacked body.

[0010] The block is in contact with the side 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.

[0011] The Young's modulus of at least the portion of the block that is in contact with the side of the positive electrode active material layer and / or the negative electrode active material layer is 50 GPa or more.

[0012] In the stacking direction of the laminate, the two ends of the block are isolated from the positive current collector and the negative current collector.

[0013] <2> according to <1> The solid-state battery mentioned above can be:

[0014] The block is fixed to the outer casing.

[0015] <3> according to <1> or <2> The solid-state battery mentioned above can be:

[0016] The flexural strength of at least the portion of the block that is in contact with the side of the positive electrode active material layer and / or the negative electrode active material layer is 500 MPa or more.

[0017] <4> according to <1> ~ <3> The solid-state battery described in any of the above can be:

[0018] The positive electrode active material layer contains sulfur (S).

[0019] In a direction orthogonal to the stacking direction of the laminate, the solid electrolyte layer extends beyond the positive electrode active material layer.

[0020] The block is in contact with the side of the positive electrode active material layer and one main surface and side of the solid electrolyte layer. In the cross section of the stacked body in the stacking direction, the block has an L-shape.

[0021] <5> according to <1> ~ <4> The solid-state battery described in any one of the above can be:

[0022] The block has a first block in contact with the side of the positive electrode active material layer and a second block in contact with the first block and the solid electrolyte layer.

[0023] The Young's modulus of the second block is lower than that of the first block.

[0024] According to this disclosure, a solid-state battery in which the solid electrolyte layer is less prone to cracking can be provided. Attached Figure Description

[0025] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention are described below with reference to the accompanying drawings, wherein like reference numerals denote like elements.

[0026] Figure 1 This is a schematic cross-sectional view showing an example of the configuration of the solid-state battery of this disclosure.

[0027] Figure 2 This is a schematic cross-sectional view illustrating another configuration example of the solid-state battery of this disclosure.

[0028] Figure 3 This is a schematic cross-sectional view illustrating another configuration example of the solid-state battery of this disclosure.

[0029] Figure 4 This is a schematic cross-sectional view illustrating another configuration example of the solid-state battery of this disclosure. Detailed Implementation

[0030] The embodiments of this disclosure will now be described. These descriptions and examples are illustrative and do not limit the scope of the embodiments.

[0031] In this disclosure, the term "process" is not limited to an independent process. Even if it cannot be clearly distinguished from other processes, it is included in this term as long as the purpose of the process can be achieved.

[0032] In this disclosure, "A and / or B" is synonymous with "at least one of A and B". That is, "A and / or B" means: it can be only A, only B, or a combination of A and B.

[0033] In this disclosure, the numerical range represented by “~” indicates the range to which the values ​​recorded before and after “~” are included, respectively, as the minimum and maximum values.

[0034] In the numerical ranges described in this disclosure, the upper or lower limit value described in one numerical range can also be replaced by the upper or lower limit value of other numerical ranges described in different stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that range can also be replaced by the value shown in the embodiments.

[0035] In the case of reference to the amount of each component in the composition in this disclosure, if there are multiple substances in the composition that are equivalent to each component, unless otherwise specified, it means the total amount of the multiple substances present in the composition.

[0036] Solid-state batteries

[0037] The solid-state batteries disclosed herein include so-called all-solid-state batteries that use a solid electrolyte as the electrolyte. In the solid-state batteries of this disclosure, the solid electrolyte may comprise an electrolyte solution comprising less than 10% by mass of the total electrolyte, or it may be a composite solid electrolyte comprising an inorganic solid electrolyte and a polymer electrolyte.

[0038] The solid-state battery disclosed herein comprises a stack, an outer casing, and a bulk body. The stack is formed by sequentially stacking a positive current collector, a positive active material layer, a solid electrolyte layer, a negative active material layer, and a negative current collector. The outer casing houses the stack internally. The bulk body contacts the sides of the positive and / or negative active material layers and is fixed to the outer casing and / or the stack. The Young's modulus of at least the portion of the bulk body in contact with the sides of the positive and / or negative active material layers is 50 GPa or more. Furthermore, in the stacking direction of the stack, both ends of the bulk body are isolated from the positive and negative current collectors.

[0039] In this disclosure, fixing the components to each other means that the components do not shift in position relative to each other. Fixing is achieved, for example, by pressing the components together, fastening the components, or joining them using resin.

[0040] In the solid-state battery disclosed herein, the solid electrolyte layer is unlikely to develop cracks. The mechanism is hypothesized as follows.

[0041] Because the bulk material is in contact with the side of the active material layer, there is no space for the active material layer to expand in the longitudinal direction. Furthermore, the bulk material is fixed to the outer casing and / or laminate, and at least the portion in contact with the side of the active material layer has a Young's modulus of 50 GPa or higher, making it difficult to deform. Therefore, volume changes in the active material layer are suppressed, making it difficult for cracks in the solid electrolyte layer caused by volume changes in the active material layer to occur.

[0042] The solid-state battery disclosed herein ensures its function and safety by isolating the two ends of the block body from the positive and negative current collectors along the lamination direction of the laminate. This is because the block body does not damage the current collectors and does not obstruct the connection between the current collectors and the electrode tabs. Furthermore, the constraint pressure exerted by the external materials along the lamination direction is reliably applied to the laminate. Additionally, since there is space between the block body and the current collectors to release internal pressure, the risk of battery rupture during battery expansion is low.

[0043] The Young's modulus of a bulk material is an indicator of its resistance to deformation. From the viewpoint of suppressing the expansion of the active material layer, the Young's modulus of at least the portion of the bulk material in contact with the sides of the positive and / or negative active material layers is 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. There is no upper limit to the Young's modulus of the bulk material, for example, it is 1000 GPa or less.

[0044] From the viewpoint of suppressing the expansion of the active material layer, the bending strength of the portion of the block that is in contact with the side of the positive electrode active material layer and / or the negative electrode active material layer is preferably 500 MPa or more, more preferably 550 MPa or more, and even more preferably 600 MPa or more.

[0045] The inventors conducted a solid-state battery simulation and obtained the following results: when the positive electrode active material layer is stretched to its maximum in a direction orthogonal to the stacking direction, a force equivalent to a bending strength of 500 MPa is applied to the bulk material arranged to cover the outer periphery of the positive electrode active material layer. Therefore, the bulk material preferably has the aforementioned bending strength.

[0046] There is no upper limit to the bending strength of the block, for example, below 1200 MPa.

[0047] A bulk component is a component made of insulating and electrochemically stable materials. A bulk component can be a single component or a combination of multiple components (e.g., two or three).

[0048] The methods for determining the Young's modulus and flexural strength of a block are as follows.

[0049] The test pieces are prepared from the same material as the actual block. The thickness direction of the actual block (the stacking direction of the laminate) is the thickness direction of the test piece. The length direction of the actual block (the direction orthogonal to the stacking direction of the laminate) is the length direction of the test piece. When the block is composed of multiple components, test pieces are made for each component.

[0050] When the material is ceramic or similar, the Young's modulus (GPa) of the block is determined by a three-point bending test according to JIS R1602 "Test Method for Elastic Modulus of Fine Ceramics". The flexural strength (MPa) of the block is determined by a three-point bending test according to JIS R1601 "Test Method for Room Temperature Flexural Strength of Fine Ceramics".

[0051] When the material is resin, Young's modulus (GPa) (tensile modulus of elasticity) is determined according to JIS K7161 "Plastics - Determination of tensile properties". Flexural strength (MPa) is determined according to JIS K7171 "Plastics - Determination of flexural properties".

[0052] All experiments were conducted in an environment with a temperature of 23℃ and a relative humidity of 50%.

[0053] In one embodiment of the solid-state battery disclosed herein, the bulk material is in contact with the side of the positive electrode active material layer, and the Young's modulus of at least the portion of the bulk material in contact with the side of the positive electrode active material layer is 50 GPa or more. Since the positive electrode active material layer is prone to volume changes, the bulk material is disposed in contact with the positive electrode active material layer.

[0054] In one embodiment of the solid-state battery disclosed herein, the block is fixed to an outer casing. The force of the outer casing securing the block and the stack acts as a reaction force against the expansion of the active material layer, which can more effectively suppress the expansion of the active material layer compared to fixing the block to the stack.

[0055] Reference Figures 1-4 The structure of the solid-state battery disclosed herein will be described. Figures 1-4 These are schematic cross-sectional views of embodiments of solid-state batteries, which are cross-sections parallel to the stacking direction of the laminate. Figures 1-4This is a schematic cross-sectional view used to illustrate the location of the constituent elements, abstracting or simplifying the construction of each element. The sizes of the components in the attached drawing are conceptual, and the relative sizes between components are not limited to these dimensions. Figures 1-4 In the accompanying drawings, the same reference numerals are used to describe components that have the same function.

[0056] Solid-state batteries 101-104 each have a stacked body 40, a block 50, an outer casing 60, a positive electrode tab 71, and a negative electrode tab 72. The stacked body 40 is formed by stacking 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 in this order. The block 50 of solid-state batteries 102 and 104 is composed of a first block 51 and a second block 52. The metal interface layer 12 is provided in one example of the embodiment, but it may also be omitted.

[0057] Solid-state batteries 101-104 include a stacked body 40, which is formed by stacking one layer each of 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. The solid-state batteries of this disclosure are not limited to the above-described manner. For example, the solid-state batteries of this disclosure may also be solid-state batteries having a stacked body in which the positive electrode current collector 31, the positive electrode active material layer 21, the solid electrolyte layer 11, the negative electrode active material layer 22, the negative electrode current collector 32, the negative electrode active material layer 22, the solid electrolyte layer 11, the positive electrode active material layer 21, and the positive electrode current collector 31 are stacked in this order.

[0058] In solid-state batteries 101-104, the outer casing 60 is pressed onto the block 50. Thus, the block 50 is fixed to the outer casing 60 and the laminate 40.

[0059] In solid-state batteries 101 and 102, the solid electrolyte layer 11 extends beyond the positive electrode active material layer 21 in a direction orthogonal to the stacking direction of the laminate 40, and the block 50 contacts 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-state batteries 101 and 102, the block 50 has an L-shape in cross-section along the stacking direction of the laminate 40. The block 50 of this embodiment has a stable configuration, making it easier to place inside the battery and more effectively suppressing the expansion of the positive electrode active material layer 21.

[0060] In solid-state batteries 103 and 104, the layers of the stack 40 have the same length in a direction orthogonal to the stacking direction of the stack 40, and the block 50 is in contact with the side surfaces of the positive electrode active material layer 21, the solid electrolyte layer 11, and the negative electrode active material layer 22. In solid-state batteries 103 and 104, the block 50 has a rectangular shape in cross-section along the stacking direction of the stack 40.

[0061] Lines e1 and e2 represent the positions of the upper surface (the surface on the side of the positive current collector 31) and the lower surface (the surface on the side of the negative current collector 32) of the block 50 in the stacking direction of the laminate 40, respectively. Lines f1 and f2 represent the positions of the lower surface (the surface on the side of the block 50) of the positive current collector 31 and the upper surface (the surface on the side of the block 50) of the negative current collector 32 in the stacking direction of the laminate 40, respectively.

[0062] Lines e1 and f1 are isolated, and lines e2 and f2 are isolated. That is, in the stacking direction of the laminate 40, the two ends of the block 50 are isolated from the positive current collector 31 and the negative current collector 32.

[0063] The solid-state batteries 102 and 104 have a first block 51 in contact with the side of the positive electrode active material layer 21 and a second block 52 in contact with the first block 51 and the solid electrolyte layer 11. The first block 51 and the second block 52 can be components of the same material or components of different materials. The Young's modulus and / or flexural strength of the first block 51 and the second block 52 can be the same value or different values.

[0064] From the viewpoint of suppressing the expansion of the positive electrode active material layer 21, the Young's modulus of the first block 51 is 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. The flexural strength of the first block 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 51 include components made of ceramics (including fine ceramics), artificial crystal, quartz glass, borosilicate glass, etc.

[0065] From the viewpoint of preventing damage to the outer casing 60 and the laminate 40, the second block 52 is preferably a component that is not too rigid. Therefore, the Young's modulus of the second block 52 is preferably lower than that of the first block 51, preferably less than 50 GPa, more preferably less than 30 GPa, and even more preferably less than 10 GPa. The flexural strength of the second block 52 is preferably less than 300 MPa, more preferably less than 200 MPa, and even more preferably less than 150 MPa. For example, a component made of resin can be cited as the second block.

[0066] The following describes in detail the layers and outer casing that make up the laminate. Reference numerals are omitted in the following description.

[0067] [Positive current collector]

[0068] The positive current collector can be in the shape of, for example, foil or mesh. Materials used for the positive current collector include, for example, stainless steel, aluminum, nickel, iron, titanium, and carbon. Aluminum alloy foil or aluminum foil is preferred as the positive current collector.

[0069] [Positive electrode active material layer]

[0070] The positive electrode active material layer contains a positive electrode active material. The positive electrode active material layer may also contain, as needed, at least one of a solid electrolyte for the positive electrode, a conductive additive, and a binder. All known positive electrode active material layers can be used as the positive electrode active material layer.

[0071] One example of an embodiment of the positive electrode active material layer is a layer containing a positive electrode active material having sulfur (S), a sulfur-containing compound having phosphorus (P) and sulfur (S), and a conductive additive, but substantially free of lithium (Li). In this embodiment, the positive electrode compound described in Japanese Patent Application Publication No. 2019-212615 can be used.

[0072] The aforementioned positive electrode active material layer has low irreversible capacity, and its capacity is difficult to reduce. By applying the aforementioned positive electrode active material layer to the solid-state battery of this disclosure, the reliability of the solid-state battery can be further improved.

[0073] The preferred form of sulfur is S8 sulfur, which is elemental sulfur. S8 sulfur can be any of the crystal forms of α sulfur, β sulfur, and γ sulfur.

[0074] Sulfur-containing compounds preferably contain a PS4 structure, which is an ortho-position structure of element P. Sulfur-containing compounds may contain an ortho-position structure of element M (M being, for example, Ge, Sn, Si, B, or Al). Examples of ortho-position structures of element M include GeS4, SnS4, SiS4, BS3, and AlS3 structures. Sulfur-containing compounds may also contain sulfides of element P (e.g., P2S5).

[0075] Examples of conductive additives include carbon materials, metallic materials, and conductive polymers. Examples of carbon materials include carbon black (e.g., acetylene black, furnace black, Ketjen black), fibrous carbon (e.g., fumed carbon fibers, carbon nanotubes, carbon nanofibers), graphite, and fluorinated carbon. Examples of metallic materials include metal powders (e.g., aluminum powder), conductive whiskers (e.g., zinc oxide, potassium titanate), and conductive metal oxides (e.g., titanium oxide). Examples of conductive polymers include polyaniline, polypyrrole, and polythiophene. Conductive additives can be used alone or in combination of two or more.

[0076] Examples of adhesives include halogenated vinyl resins, rubbers, and polyolefin resins. Other components include oxide solid electrolytes, halide solid electrolytes, thickeners, surfactants, dispersants, wetting agents, defoamers, and solvents.

[0077] [Negative current collector]

[0078] The negative current collector can be in the shape of, for example, foil or mesh. Materials used for the negative current collector include, for example, stainless steel, aluminum, copper, nickel, iron, titanium, and carbon. Copper foil or nickel foil is preferred as the negative current collector.

[0079] [Negative electrode active material layer]

[0080] The negative electrode active material layer contains a negative electrode active material. The negative electrode active material layer may also contain, as needed, at least one of a solid electrolyte for the negative electrode, a conductive additive, and a binder. All known negative electrode active material layers can be used as the negative electrode active material layer.

[0081] Examples of negative electrode active materials include Li-based active materials such as lithium metal, carbon-based active materials such as graphite, oxide-based active materials such as lithium titanate, and Si-based active materials such as elemental Si.

[0082] As an example of an embodiment of the negative electrode active material layer, examples include metallic Li foil and Li-X alloy foil (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.

[0083] [Solid electrolyte layer]

[0084] The solid electrolyte layer contains a solid electrolyte. The solid electrolyte may also contain an electrolyte solution comprising less than 10% by mass of the total electrolyte. The solid electrolyte may also be a composite solid electrolyte comprising an inorganic solid electrolyte and a polymer electrolyte.

[0085] The solid electrolyte preferably includes one selected from sulfide solid electrolytes, oxide solid electrolytes and halide solid electrolytes.

[0086] The sulfide solid electrolyte contains sulfur (S) as the main anionic element, and preferably also contains, for example, Li and A. The A element is selected from at least one of P, As, Sb, Si, Ge, Sn, B, Al, Ga and In.

[0087] Oxide solid electrolytes contain oxygen (O) as the main anionic element, and may also contain elements such as Li and Q. The Q element is selected from at least one of Nb, B, Al, Si, P, Ti, Zr, Mo, W and S.

[0088] The halide solid electrolyte is preferably a solid electrolyte containing Li, M and X (M represents at least one of Ti, Al and Y, and X represents F, Cl or Br).

[0089] The solid electrolyte layer may or may not contain an adhesive. Examples of adhesives 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 adhesive may be a diene-based rubber containing double bonds in its main chain, such as a butadiene-based rubber with butadiene comprising more than 30 mol% of the total.

[0090] [Metal Interface Layer]

[0091] A metal interface layer can be present between the solid electrolyte layer and the negative electrode active material layer. The metal interface layer can be, for example, a metal vapor-deposited film of In, Sn, or an In-Sn alloy.

[0092] [Exterior body]

[0093] Examples of outer packaging include aluminum laminated packaging (pack) and metal cans.

[0094] [Solid-state battery manufacturing method]

[0095] The solid-state battery disclosed herein is manufactured, for example, through the following steps 1 to 3.

[0096] The first step involves stacking the positive current collector, positive active material layer, solid electrolyte layer, negative active material layer, and negative current collector in this order to manufacture a laminate. Alternatively, a metal interface layer can be stacked between the solid electrolyte layer and the negative active material layer.

[0097] The second step is to arrange blocks around the laminate.

[0098] The third step is to configure the positive and negative electrode tabs, store them in the outer casing, and perform vacuum sealing.

[0099] The solid-state battery disclosed herein is not limited in shape or application. For example, the solid-state battery disclosed herein can be applied to HEVs (Hybrid Electric Vehicles), PHEVs (Plug-in Hybrid Electric Vehicles), and BEVs (Battery Electric Vehicles).

[0100] The following embodiments are provided to further illustrate the solid-state battery of this disclosure. The materials, dimensions, combinations, etc., shown in the following embodiments can be appropriately modified without departing from the spirit of this disclosure. Therefore, the solid-state battery of this disclosure should not be interpreted limitingly by the specific examples shown below.

[0101] Unless otherwise specified, the following instructions shall be followed by synthesis, processing, and manufacturing at room temperature (25℃±3℃).

[0102] <Preparation of Experimental Cells>

[0103] [Unit Structure]

[0104] Laminated structure: Roughened Al foil / S-P2S5-C compound layer / sulfide solid electrolyte / Sn layer / Li-10% Mg alloy foil / Roughened Ni foil

[0105] Blocks: Material and size, which will be described in Types 1 through 4.

[0106] Positive electrode tab: Al foil

[0107] Negative electrode tab: Ni foil

[0108] Laminated film: Aluminum laminate

[0109] [The production of the positive electrode]

[0110] S (vacuum-dried at 80°C), P2S5, and monolayer CNT (vacuum-dried at 120°C) were mixed in a mortar at a mass ratio of 42:35:23. 1.7 g of the mixture and 80 g of 4 mm diameter zirconia balls were added to each ball mill jar, and the mixture was ball-milled at 400 rpm for a total of 36 hours. After ball milling, the mixture was dry-classified using a 38 μm sieve to obtain a sulfur cathode mixture. A cathode slurry was prepared using mesitylene as the solvent at a mass ratio of sulfur cathode mixture to binder of 99.7:0.3. The cathode slurry was coated onto a roughened Al foil with a coating gap of 220 μm, pre-dried at 50°C, and then formally dried at 100°C for 30 minutes to obtain the cathode (cathode current collector and cathode active material layer). The cathode was then cut into a circle of a specified diameter.

[0111] [Fabrication of the solid electrolyte layer]

[0112] Heptane was used as the solvent, and a solid electrolyte slurry was prepared at a mass ratio of solid electrolyte (median particle size 0.5 μm) to binder of 90.9:9.1. The solid electrolyte slurry was coated onto a release film with a coating gap of 450 μm, pre-dried at room temperature for approximately 3 hours, and then formally dried at 165°C for 1 hour to obtain a solid electrolyte layer. The solid electrolyte layer with the release film was punched into a circle of a specified diameter, and the coated surfaces of two pieces were overlapped and pressed at 6 tons (t) at room temperature. After pressing, the release film was peeled off to obtain an individual solid electrolyte layer. Subsequently, a metal interface layer (Sn layer, 0.1 μm thick) was formed on one side of the individual solid electrolyte layer by sputtering.

[0113] [Making the negative electrode]

[0114] A Li-10% Mg alloy foil (100 μm thick) is punched into a circle of a specified diameter. A roughened Ni foil is also punched into a circle of a specified diameter. The Li-10% Mg alloy foil and the roughened Ni foil are then bonded together at a ratio of 0.1 tons to obtain the negative electrode (negative electrode current collector and negative electrode active material layer).

[0115] [Fabrication of laminated units]

[0116] A laminate is formed by stacking the negative electrode, independent solid electrolyte layer, and positive electrode in that order. Then, bulk materials are placed around the laminate. Next, positive and negative electrode tabs are added, and the laminate is vacuum-sealed within the laminate. The sealed unit is then isotropically pressed at 300 MPa using CIP (Cold Isostatic Pressing) to obtain the laminated unit.

[0117] The experimental units of types 1 to 4 were manufactured through the above procedures. The dimensions of each type are as follows:

[0118] [Type 1]

[0119] Type 1 has Figure 2 The shape of the diagram.

[0120] The diameter of each layer is the diameter of the circle being punched out. The thickness of each layer is the thickness of each layer during manufacturing.

[0121] Positive current collector: 11.28mm in diameter

[0122] Positive electrode active material layer: diameter 11.28 mm, layer thickness 60 μm

[0123] Solid electrolyte layer: 14.50 mm in diameter, 75 μm in thickness

[0124] Metal interface layer: 14.50 mm in diameter, 0.1 μm in thickness

[0125] Negative electrode active material layer: diameter 13.00 mm, layer thickness 100 μm

[0126] Negative current collector: 14.50mm in diameter

[0127] Part 1: A component with an inner diameter hole of 11.28 mm on a 30 mm × 30 mm square plate, and a thickness of 40 μm. The material is PEEK resin, high-strength aluminum oxide, or sapphire.

[0128] The second component: A component with a hole of 15.10 mm inner diameter on a 30 mm × 30 mm square plate, and a thickness of 135 μm. The material is the same as the first component. (Considering that the solid electrolyte layer elongates in a direction orthogonal to the stacking direction during unit fabrication, the inner diameter of the second component is slightly larger than the diameter of 14.50 mm.)

[0129] The first block is configured to contact the lower side of the positive electrode active material layer (the side closest to the solid electrolyte layer) and a main surface of the solid electrolyte layer. The second block is configured to contact the lower surface of the first block (the surface on the side of the solid electrolyte layer) and the side of the solid electrolyte layer.

[0130] [Type 2]

[0131] Type 2 has Figure 3 The shape of the diagram.

[0132] The diameter of each layer is the diameter of the circle being punched out. The thickness of each layer is the thickness of each layer during manufacturing.

[0133] Positive current collector: 11.28mm in diameter

[0134] Positive electrode active material layer: diameter 11.28 mm, layer thickness 60 μm

[0135] Solid electrolyte layer: 11.28 mm in diameter, 75 μm in thickness

[0136] Metal interface layer: 11.28 mm in diameter, 0.1 μm in thickness.

[0137] Negative electrode active material layer: diameter 11.28 mm, layer thickness 100 μm

[0138] Negative current collector: 11.28mm in diameter

[0139] Block: A component with an inner diameter hole of 11.28 mm in a 30 mm × 30 mm square plate, and a thickness of 210 μm. The material is PEEK resin, high-strength alumina, or sapphire.

[0140] The block is configured to contact the lower side of the positive electrode active material layer (the side closest 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 closest to the solid electrolyte layer).

[0141] [Type 3]

[0142] Type 3 has Figure 2 The schematic diagram shows the shape of the experimental unit. It was made in the same way as the experimental unit of type 1, but the material of the second block was entirely PEEK resin.

[0143] [Type 4]

[0144] Type 4 has Figure 4 The schematic diagram shows the form. The experimental unit was made in the same way as the experimental unit of type 2, but the blocks were changed as follows to create the experimental unit.

[0145] Part 1: A component with an inner diameter hole of 11.28 mm on a 20 mm × 20 mm square plate, and a thickness of 40 μm. The material is PEEK resin, high-strength aluminum oxide, or sapphire.

[0146] The second component is a member with a hole of 11.28 mm inner diameter on a 30 mm × 30 mm square plate, with a thickness of 210 μm. It has a stepped portion (internal size 20 mm × 20 mm, height 40 μm) on the upper part of its inner surface for the first component to be inserted. The material is PEEK resin.

[0147] The first block is embedded into the stepped portion of the second block, and the block is configured to contact the lower side of the positive electrode active material layer (the side closest 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 closest to the solid electrolyte layer).

[0148] <Performance Evaluation>

[0149] [Initial Cycle Test]

[0150] A constant current density of 0.584 mA / cm² is applied to the cell within a cutoff voltage range of 3.1 V to 1.2 V. 2 (1C=5.84mA / cm 2 The electrode was subjected to an initial cycle test at 60°C (equivalent to 0.1°C) to confirm whether the solid electrolyte layer at the initial expansion of the positive electrode had any cracks.

[0151] 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.

[0152] Table 1

[0153]

[0154] Table 2

[0155]

Claims

1. A solid-state battery, comprising a stacked body, an outer casing, and a bulk body, The laminate is composed of a positive current collector, a positive active material layer, a solid electrolyte layer, a negative active material layer, and a negative current collector stacked in this order. The outer casing internally houses the stacked body. The block is in contact with the side 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 that is in contact with the side 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, the two ends of the block are isolated from the positive current collector and the negative current collector.

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

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

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

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

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