All-solid-state battery

Abstract

The present disclosure has an object to provide a small full-solid battery with good structural reliability. The full-solid battery includes a battery cell, a first current collector disposed on a first surface of the battery cell, a second current collector disposed on a second surface of the battery cell opposite to the first surface, and an exterior body that protects the battery cell, the first current collector, and the second current collector. The full-solid battery has a size of 4 cm 2 Hereinafter, the battery cell contains a sulfide solid electrolyte, the exterior body has a first exterior member and a second exterior member, the first exterior member is disposed on the first surface side of the battery cell, the second exterior member is disposed on the second surface side of the battery cell, a resin layer A is disposed between at least one of the first exterior member and the first current collector and the second exterior member and the second current collector, a resin layer B is disposed on a side surface portion of the battery cell, and the resin layer A and the resin layer B each contain an adhesive resin.

Description

Technical Field

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

[0002] All-solid-state batteries are batteries with a solid electrolyte layer between the positive and negative electrode layers. Compared with liquid batteries that have an electrolyte containing flammable organic solvents, they have the advantage of being easier to simplify safety devices. For example, Patent Document 1 discloses a laminated battery that includes an electrode body, a laminated outer casing, and a connector membrane, with a thermoplastic resin layer provided at the edge of the laminated outer casing.

[0003] Prior art literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2019-194949 Summary of the Invention

[0005] When miniaturizing all-solid-state batteries, their structural reliability can easily decrease. For example, moisture can easily penetrate the battery cells, causing cracks during manufacturing. This disclosure was made in view of the above-mentioned realities, and its main objective is to provide a small all-solid-state battery with good structural reliability.

[0006] To address the aforementioned issues, this disclosure provides an all-solid-state battery comprising: a battery cell, a first current collector disposed on a first surface of the battery cell, a second current collector disposed on a second surface of the battery cell opposite to the first surface, and an outer casing protecting the battery cell, the first current collector, and the second current collector. The all-solid-state battery has a size of 4 cm. 2 The battery cell contains a sulfide solid electrolyte, and the outer casing has a first outer casing member and a second outer casing member. The first outer casing member is disposed on the first side of the battery cell, and the second outer casing member is disposed on the second side of the battery cell. A resin layer A is disposed between the first outer casing member and the first current collector member, and / or between the second outer casing member and the second current collector member. A resin layer B is disposed on the side surface of the battery cell. The resin layer A and the resin layer B each contain an adhesive resin.

[0007] According to this disclosure, a solid-state battery with good structural reliability is formed by distributing a resin layer A between the first outer component and the first current collector, and / or between the second outer component and the second current collector, and distributing a resin layer B on the side of the battery cell.

[0008] In the above disclosure, a resin layer A1 can be disposed between the first outer component and the first current collector component as the resin layer A, and when viewed from above along the thickness direction, the resin layer A1 is configured to include the entire battery cell.

[0009] In the above disclosure, a resin layer A2 can be disposed between the second outer component and the second current collector as the resin layer A, and when viewed from above along the thickness direction, the resin layer A2 is configured to include the entire battery cell.

[0010] In the above disclosure, the resin layer B can be disposed over the entire area of ​​the side surface from the end of the first side surface to the end of the second side surface.

[0011] In the above disclosure, when viewed from above along the thickness direction, the resin layer B can be disposed on the entire outer edge of the battery cell.

[0012] In the above disclosure, the area of ​​the battery cell can be 0.1 cm². 2 the following.

[0013] This disclosure has the effect of providing a small all-solid-state battery with good structural reliability. Attached Figure Description

[0014] Figure 1 This is a schematic top view illustrating the all-solid-state battery of this disclosure.

[0015] Figure 2 yes Figure 1 AA section diagram.

[0016] Figure 3 yes Figure 1 BB cross-section diagram.

[0017] Figure 4 This is a schematic cross-sectional view illustrating resin layer A in this disclosure.

[0018] Figure 5 This is a schematic top view illustrating resin layer A in this disclosure.

[0019] Figure 6 This is a schematic cross-sectional view illustrating resin layer B in this disclosure.

[0020] Figure 7 This is a schematic top view illustrating resin layer B in this disclosure.

[0021] Figure 8 This is a schematic cross-sectional view illustrating a battery cell in this disclosure.

[0022] Figure 9 This is a schematic perspective view illustrating the method for manufacturing the evaluation battery in Example 1.

[0023] Figure 10 This is a schematic cross-sectional view of the evaluation battery produced in Example 1.

[0024] Figure 11 The results are from charge-discharge tests conducted on the evaluation battery produced in Example 1.

[0025] Figure 12 The results are from charge-discharge tests conducted on the evaluation battery produced in Comparative Example 1.

[0026] Explanation of reference numerals in the attached figures

[0027] 1… Positive electrode layer

[0028] 2… Negative electrode layer

[0029] 3… Solid electrolyte layer

[0030] 4…Positive current collector

[0031] 5… Negative current collector

[0032] 10… battery cells

[0033] 11…First collector component

[0034] 12…Second collector component

[0035] 20…outer body

[0036] 21…First external component

[0037] 22…Second External Component

[0038] 31…Resin layer A

[0039] 32…Resin layer B

[0040] 100… All-solid-state battery Detailed Implementation

[0041] The all-solid-state battery of this disclosure will now be described in detail with the aid of accompanying drawings. The figures shown below are schematic diagrams, and the size and shape of the parts have been appropriately exaggerated for ease of understanding.

[0042] Figure 1 This is a schematic top view illustrating the all-solid-state battery of this disclosure. Figure 1The all-solid-state battery 100 shown includes a battery cell 10, an outer casing 20, and a first current collector 11 and a second current collector 12. The battery cell 10 has a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. The outer casing 20 protects the battery cell 10. The first current collector 11 and the second current collector 12 are used to extract the electricity generated in the battery cell 10. The battery cell 10 contains a sulfide solid electrolyte. Furthermore, the size of the all-solid-state battery 100 is represented by the product of its length X in a first direction and its length Y in a second direction orthogonal to the first direction, typically 4 cm. 2 Hereinafter, the first direction is the end of the first current collector 11 ( Figure 1 The end on the left side of the middle paper) and the end of the second collector 12 ( Figure 1 The direction of the connection at the right end of the paper.

[0043] Figure 2 yes Figure 1 AA section diagram, Figure 3 yes Figure 1 The BB cross-section diagram in the image. Figure 2 , Figure 3 As shown, the all-solid-state battery 100 includes: a battery cell 10, a first current collector 11 disposed on a first surface S1 of the battery cell 10, a second current collector 12 disposed on a second surface S2 of the battery cell 10 opposite to the first surface S1, and an outer casing 20 protecting the battery cell 10, the first current collector 11, and the second current collector 12. The outer casing 20 includes: a first outer casing 21 disposed on the first surface S1 side of the battery cell 10 and a second outer casing 22 disposed on the second surface S2 side of the battery cell 10. Furthermore, a resin layer A1 (resin layer 31) is disposed between the first outer casing 21 and the first current collector 11, and a resin layer A2 (resin layer 31) is disposed between the second outer casing 22 and the second current collector 12. Additionally, a resin layer B (resin layer 32) is disposed on the side surface of the battery cell 10. Resin layers A1, A2, and B each contain an adhesive resin.

[0044] According to this disclosure, a solid-state battery with good structural reliability is formed by distributing a resin layer A between the first outer component and the first current collector, and / or between the second outer component and the second current collector, and distributing a resin layer B on the side of the battery cell.

[0045] As described above, miniaturizing all-solid-state batteries can easily reduce their structural reliability. For example, moisture can easily penetrate the battery cell, leading to cracks during manufacturing. In this disclosure, resin layers A and B, each containing an adhesive resin, are disposed at predetermined locations. By protecting the area around the battery cell with resin layers A and B, moisture penetration into the battery cell can be suppressed. Furthermore, by acting as buffering materials, resin layers A and B can prevent cracks from forming in the battery cell during manufacturing.

[0046] Furthermore, when the size of an all-solid-state battery is large, for example, the area of ​​the sealing portion that welds the outer components together can be significantly increased, making it easier to improve the structural reliability of the outer components. Conversely, if the all-solid-state battery is miniaturized (for example, to a length of 2 cm × width of 2 cm or less), there are more size constraints, and therefore structural reliability is more likely to decrease. In addition, if the sulfide solid electrolyte contained in the battery cell reacts with moisture, its performance will be significantly reduced. Therefore, when using battery cells containing sulfide solid electrolytes, strict moisture management is required. Thus, in this disclosure, by using resin layer A and resin layer B, the problems unique to all-solid-state batteries that use sulfide solid electrolytes for miniaturization are solved.

[0047] 1. Structure of all-solid-state batteries

[0048] The all-solid-state battery disclosed herein is typically 4 cm in size. 2 The following. (e.g.) Figure 1 As shown, the size of the all-solid-state battery is represented by the product of the length X of the all-solid-state battery 100 in the first direction and the length Y of the all-solid-state battery 100 in the second direction orthogonal to the first direction, wherein the first direction is the direction connecting the end of the first current collector 11 and the end of the second current collector 12. For example, the first direction corresponds to the long side direction of the first current collector 11 and the second current collector 12, and the second direction corresponds to the short side direction of the first current collector 11 and the second current collector 12.

[0049] The size of a solid-state battery can be 2cm. 2 The following can also be 1cm 2 Below. On the other hand, the size of an all-solid-state battery is, for example, 0.04 cm. 2 The above can also be 0.1cm 2 The above applies. X and Y are, for example, 2 cm or less, or even 1 cm or less. On the other hand, X and Y are, for example, 0.2 cm or more. Furthermore, the area of ​​the battery cell (the area viewed from above along the thickness direction) is not particularly limited, and is, for example, 0.5 cm². 2 The following can also be 0.3cm 2Below. On the other hand, the area of ​​the battery cell is, for example, 0.01 cm². 2 above.

[0050] In this disclosure, a resin layer A is typically disposed between the first outer component and the first current collector, and / or between the second outer component and the second current collector. By disposing of the resin layer A, the adhesion between the outer component and the current collector is improved, thereby enhancing the structural reliability of the all-solid-state battery. Particularly when the outer component has a heat-fused resin layer as an inner layer (the layer closest to the battery cell) and the current collector is metal, the adhesion between the outer component and the current collector is significantly improved by disposing of the resin layer A therebetween. The resin contained in the resin layer A is bonded to the resin contained in the heat-fused resin layer on one surface side and firmly bonded to the metal current collector on the other surface side, thereby significantly improving the adhesion between the outer component and the current collector.

[0051] For example Figure 4 In this configuration, a resin layer A1 is disposed between the first outer casing 21 and the first current collector 11, and a resin layer A2 is disposed between the second outer casing 22 and the second current collector 12. Furthermore, although not specifically illustrated, either resin layer A1 or resin layer A2 may be omitted. Additionally, as... Figure 4 As shown, the thickness of resin layer A (resin layer 31) is T1. T1 is not particularly limited; for example, it can be 50 μm or more, 70 μm or more, or 90 μm or more. If T1 is too small, good structural reliability may not be achieved. On the other hand, T1 can be, for example, 300 μm or less, or even 200 μm or less. If T1 is too large, the proportion of battery cells becomes relatively small, and good volumetric energy density may not be achieved.

[0052] Furthermore, when viewed from above along the thickness direction, resin layer A is typically configured to overlap with at least a portion of the battery cell. Specifically, as shown... Figure 5 As shown, resin layer A (resin layer 31) is preferably configured to include the entire battery cell 10. This improves structural reliability. In this disclosure, it is preferable that both resin layers A1 and A2 are configured to include the entire battery cell 10 when viewed from above along the thickness direction.

[0053] In this disclosure, a resin layer B is typically disposed on the side surface of the battery cell. For example... Figure 6 In this configuration, a resin layer B (resin layer 32) is disposed on the side portion 10s of the battery cell 10. The resin layer B may be disposed in at least a portion of the side portion 10s of the battery cell 10. For example, Figure 6 As shown, resin layer B (resin layer 32) is preferably disposed over the entire area of ​​the side portion 10s from end t1 on the first surface S1 side to end t2 on the second surface S2 side. Furthermore, as... Figure 6As shown, the width of resin layer B (resin layer 32) is W1. W1 is not particularly limited; for example, it can be 100 μm or more, or even 1000 μm or more. If W1 is too small, good structural reliability may not be obtained. On the other hand, W1 can be, for example, 3000 μm or less, or even 2000 μm or less. If W1 is too large, the proportion of the battery cells becomes relatively small, and good volumetric energy density may not be obtained.

[0054] Furthermore, when viewed from above along the thickness direction, resin layer B is typically disposed on at least a portion of the outer edge of the battery cell. Specifically, as shown... Figure 7 As shown, resin layer B (resin layer 32) is preferably disposed around the entire circumference of battery cell 10. This improves structural reliability. In particular, resin layer B preferably completely covers the side portion of battery cell. That is, resin layer B is preferably configured so that no area of ​​the side portion of battery cell is exposed.

[0055] Furthermore, such as Figure 2 and Figure 3 As shown, there can be an interface between resin layer A (resin layer 31) and resin layer B (resin layer 32), or the two can be integrated without an interface.

[0056] 2. Components of an all-solid-state battery

[0057] The all-solid-state battery disclosed herein comprises a resin layer, a battery cell, a first current collector, a second current collector, and an outer casing.

[0058] (1) Resin layer

[0059] The all-solid-state battery disclosed herein comprises resin layer A and resin layer B as described above, which are resin layers containing an adhesive resin. The adhesive resin is not particularly limited as long as it can provide adhesion to the current collector (typically a metal current collector). Examples include modified polyolefins such as modified polypropylene (e.g., ADMER manufactured by Mitsui Chemicals Co., Ltd., a registered trademark) that acquire adhesiveness by introducing functional groups. The adhesive resins used in resin layer A and resin layer B may be the same or different.

[0060] (2) Battery cell, first current collector, second current collector

[0061] The battery cell disclosed herein typically has a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. In the battery cell, the positive current collector can be disposed on the side of the positive electrode layer opposite to the solid electrolyte layer. Similarly, the negative current collector can be disposed on the side of the negative electrode layer opposite to the solid electrolyte layer. Figure 8The battery cell 10 shown has a positive electrode layer 1, a negative electrode layer 2, an electrolyte layer 3 disposed between the positive electrode layer 1 and the negative electrode layer 2, a positive current collector 4 for collecting current in the positive electrode layer 1, and a negative current collector 5 for collecting current in the negative electrode layer 2. The battery cell may have one power generation unit with a positive electrode layer, a solid electrolyte layer, and a negative electrode layer, or it may have two or more power generation units.

[0062] The battery cell is preferably covered by resin layer A and resin layer B on its entire surface. Specifically, it is preferable to satisfy the following (i) to (iii).

[0063] (i) When viewed from above along the thickness direction, resin layer A1 and resin layer A2 are respectively configured to contain the battery cell as a whole.

[0064] (ii) Resin layer B is disposed in the entire area from the end of the first side of the side portion to the end of the second side portion.

[0065] (iii) When viewed from above along the thickness direction, the resin layer B is disposed on the entire circumference of the outer edge of the battery cell.

[0066] The battery cell has a positive electrode layer, a solid electrolyte layer, and a negative electrode layer. Furthermore, at least one of the positive electrode layer, the solid electrolyte layer, and the negative electrode layer contains a sulfide solid electrolyte. The thickness of the battery cell is not particularly limited, for example, it is 20 μm or more and 200 μm or less.

[0067] The positive electrode layer contains at least a positive electrode active material and may also contain at least one of a sulfide solid electrolyte, a conductive material, and a binder. Examples of positive electrode active materials include oxide active materials. Examples of oxide active materials include LiNi. 1 / 3 Co 1 / 3 Mn 1 / 3 O2, LiNiO2 and other rock salt layered active substances.

[0068] The sulfide solid electrolyte preferably contains, for example, elements such as Li, X (where X is at least one of P, As, Sb, Si, Ge, Sn, B, Al, Ga, and In), and S. Additionally, the sulfide solid electrolyte may contain at least one of Cl, Br, and I as a halogen element. Furthermore, the sulfide solid electrolyte may contain O. The sulfide solid electrolyte can be a glass-based sulfide solid electrolyte, a glass-ceramic-based sulfide solid electrolyte, or a crystalline sulfide solid electrolyte. Furthermore, when the sulfide solid electrolyte has a crystalline phase, examples of crystalline phases include the Thio-LISICON (sulfide crystalline lithium superionic conductor) type crystalline phase, the LGPS type crystalline phase, and the sulfogermanite type crystalline phase.

[0069] Examples of conductive materials include acetylene black, Ketjen black, VGCF, and graphite. Examples of adhesives include fluoride-based adhesives.

[0070] The negative electrode layer contains at least a negative electrode active material, and may further contain at least one of a sulfide solid electrolyte, a conductive material, and a binder. Examples of such active materials include carbon-based materials such as graphite, metal-based materials such as Si, and oxide-based active materials such as lithium titanate. The sulfide solid electrolyte, conductive material, and binder are as described above.

[0071] The solid electrolyte layer contains at least a solid electrolyte and may further contain a binder. Preferably, the solid electrolyte layer contains a sulfide solid electrolyte as the solid electrolyte. The sulfide solid electrolyte and the binder are as described above.

[0072] Examples of materials for the positive current collector include Al, SUS, and Ni. Examples of materials for the negative current collector include Cu, SUS, and Ni. Examples of shapes for the current collector include foil, mesh, and porous structures. The thickness of the current collector (positive current collector, negative current collector) is not particularly limited, but is, for example, 10 μm or more and 50 μm or less. Furthermore, the materials, shapes, and thicknesses of the current collector components (first current collector component, second current collector component) are the same as those for the current collectors described above. In the current collector components, the portion exposed from the outer casing typically functions as a terminal. Additionally, it is preferable that the first and second current collector components have different polarities.

[0073] (3)Exterior body

[0074] The outer casing is a component that protects the battery cell, the first current collector component, and the second current collector component. For example... Figure 2 As shown, the outer casing 20 has a first outer casing member 21 disposed on the first surface S1 side of the battery cell 10 and a second outer casing member 22 disposed on the second surface S2 side of the battery cell 10.

[0075] The outer casing is preferably in the form of a film (sheet). Furthermore, the outer casing may have, for example, a heat-resistant resin layer as an outer layer, a metal foil layer as an intermediate layer, and a heat-melting resin layer as an inner layer. A sealing portion can be formed by heat-melting the heat-melting resin layers together.

[0076] In the outer casing, the heat-resistant resin layer functions as a substrate layer, the metal foil layer functions as a barrier layer, and the hot-melt resin layer functions as a sealant layer. Examples of resins used in the heat-resistant resin layer include polyamides such as nylon, polyethylene terephthalate, polymethyl methacrylate, polypropylene, polycarbonate, and polyalkylene terephthalate. Examples of metal materials used in the metal foil layer include aluminum, stainless steel, titanium, nickel, and copper. Examples of resins used in the hot-melt resin layer include acid-modified polyolefins, polyethylene, and polypropylene. The thickness of the outer casing is not particularly limited, but is, for example, 100 μm or more and 300 μm or less.

[0077] (4) All-solid-state battery

[0078] The all-solid-state battery disclosed herein is typically an all-solid-state lithium secondary battery. Furthermore, the all-solid-state battery of this disclosure is small and can be used for a variety of applications. Examples of applications for all-solid-state batteries include power supplies for printed circuit boards.

[0079] Furthermore, this disclosure is not limited to the embodiments described above. The embodiments described above are illustrative, and all solutions that have the same technical concept as those described in the patent claims of this disclosure and that achieve the same effect are included within the technical scope of this disclosure.

[0080] Example

[0081] [Example 1]

[0082] (Fabrication of the positive electrode layer)

[0083] A PVDF-based binder (made by Wu Yu) was added to a polypropylene container, and a positive electrode active material (LiNi) was coated on the surface with LiNbO3. 1 / 3 Co 1 / 3 Mn 1 / 3 O2), a sulfide solid electrolyte (Li2S-P2S5 glass-ceramic), a conductive material (VGCF, manufactured by Showa Denko), and butyl butyrate were stirred for 30 seconds using an ultrasonic dispersion device (SMT UH-50). Next, the mixture was vibrated for 3 minutes using a vibrator (Shibata Scientific, TTM-1), followed by stirring with an ultrasonic dispersion device for another 30 seconds to obtain a slurry. The slurry was then coated onto an Al foil using a doctor blade method. The coating was allowed to dry naturally, and then dried on a hot plate at 100°C for 30 minutes to form a positive electrode layer on the Al foil.

[0084] (Fabrication of the negative electrode layer)

[0085] PVDF-based binder (made by Kureha), negative electrode active materials (lithium titanate, LTO), sulfide solid electrolyte (Li2S-P2S5 glass ceramic), and butyl butyrate are added to a polypropylene container and stirred for 30 seconds using an ultrasonic dispersion device (SMT UH-50) to obtain a slurry. The slurry is then coated onto a Cu foil using a doctor blade method with a coating applicator. The coating layer is allowed to dry naturally and then dried on a hot plate at 100°C for 30 minutes to form a negative electrode layer on the Cu foil.

[0086] (Fabrication of the solid electrolyte layer)

[0087] A sulfide solid electrolyte (Li2S-P2S5 glass-ceramic) and butyl butyrate were added to a polypropylene container. The PP container was stirred for 30 seconds using an ultrasonic dispersion device (SMT UH-50). Next, the PP container was vibrated for 30 minutes using a vibrator (Shibata Scientific TTM-1), followed by stirring with an ultrasonic dispersion device for 30 seconds to obtain a slurry. The slurry was then coated onto an Al foil using a doctor blade method. The coating was allowed to dry naturally, and then dried on a hot plate at 100°C for 30 minutes to form a solid electrolyte layer on the Al foil.

[0088] (Battery cell fabrication)

[0089] The Al foil of the solid electrolyte layer is peeled off by overlapping and pressing the positive electrode layer and the solid electrolyte layer together. Then, the exposed solid electrolyte layer is overlapped and pressed together with the negative electrode layer. Next, a 2mm × 5mm battery cell is formed by punching with a hand press.

[0090] (Evaluation of battery manufacturing)

[0091] according to Figure 9 Fabricate the positive electrode side laminate in the order shown. Figure 9 As shown in (a), the laminate is prepared to be cut into 4mm wide pieces. Next, as... Figure 9 As shown in (b), resin layer A is placed on the laminated film and joined using a lamination sealing machine. Then, as... Figure 9 As shown in (c), the laminated film and resin layer A are cross-arranged with the positive electrode current collector (first current collector, Al foil) cut to a width of 4 mm, and joined using a lamination sealing machine. Then, as... Figure 9 As shown in (d), a frame-shaped resin layer B is placed on an Al foil and bonded using a lamination sealing machine. This yields a positive electrode-side laminate stacked in the order of laminate film, resin layer A, Al foil, and resin layer B. Resin layers A and B use adhesive polyolefin (ADMER, registered trademark) manufactured by Mitsui Chemicals.

[0092] On the other hand, a negative current collector (second current collector, Ni foil) is used instead of the positive current collector (first current collector, Al foil). Otherwise, the negative electrode-side laminate is fabricated in the same manner as the positive electrode-side laminate. The battery cell is placed between the positive electrode-side laminate and the negative electrode-side laminate, and the battery cell is sealed using a lamination sealing machine. Thus, as... Figure 10 As shown, an evaluation battery with a layered structure of first outer component 21 / resin layer A1 / first current collector 11 / battery cell 10, resin layer B / second current collector 12 / resin layer A2 / second outer component 22 is obtained. The thickness of each component is as follows. Figure 10 As shown. Additionally, the battery size is 0.7cm. 2 (X = 10 mm, Y = 7 mm), the area of ​​the battery cell is 0.1 cm². 2 .

[0093] [Comparative Example 1]

[0094] The evaluation battery was made in the same manner as in Example 1, except that resin layer B was not used.

[0095] [Comparative Example 2]

[0096] The evaluation battery was manufactured in the same manner as in Example 1, except that resin layers A1, A2, and B were not used.

[0097] [evaluate]

[0098] (Charge / Discharge Test)

[0099] For the evaluation batteries obtained in Example 1 and Comparative Examples 1 and 2, the battery capacity was confirmed by CC-CV charge-discharge in a constant temperature bath set at 25°C within a voltage range of 3.0V-1.5V. The current density was 1 / 3C (0.055mA). The results of Example 1 and Comparative Example 1 are shown below. Figure 11 , Figure 12 .

[0100] like Figure 11 , Figure 12 As shown, the evaluation batteries obtained in Example 1 and Comparative Example 1 were confirmed to function as batteries, but Example 1 had a higher discharge capacity compared to Comparative Example 1. This is presumably because the evaluation battery in Example 1 had higher structural reliability compared to the evaluation battery in Comparative Example 1. On the other hand, in Comparative Example 2, due to insufficient sealing of the outer casing, moisture entered the battery cells, and the battery did not function as a battery.

Claims

1. An all-solid-state battery, comprising: Battery cells, The first current collector configured on the first surface of the battery cell, The second current collector is disposed on the second surface of the battery cell opposite to the first surface, and The outer casing protecting the battery cell, the first current collector, and the second current collector. The solid-state battery has a size of 4cm. 2 the following, The battery cell contains a sulfide solid electrolyte. The outer casing has a first outer casing component and a second outer casing component, the first outer casing component being disposed on the first surface side of the battery cell, and the second outer casing component being disposed on the second surface side of the battery cell. A resin layer A is disposed between the first outer casing and the first current collector, and / or between the second outer casing and the second current collector. A resin layer B is disposed on the side surface of the battery cell. The upper surface of the resin layer B facing the first surface of the battery cell is in contact with the inner surface of the first current collector facing the battery cell, and the lower surface of the resin layer B facing the second surface of the battery cell is in contact with the inner surface of the second current collector facing the battery cell. An interface exists between resin layer A and resin layer B. Resin layer A and resin layer B each contain adhesive resin. Between the first outer casing and the first current collector, a resin layer A1 is disposed as the resin layer A. When viewed from above along the thickness direction, the resin layer A1 is configured to encompass the entire battery cell. Between the second outer casing and the second current collector, a resin layer A2 is disposed as the resin layer A. When viewed from above along the thickness direction, the resin layer A2 is configured to encompass the entire battery cell. The resin layer B is disposed over the entire area of ​​the side surface from the end of the first side surface to the end of the second side surface. When viewed from above along the thickness direction, the resin layer B is disposed on the entire outer edge of the battery cell. The battery cell is not sealed by the outer casing. The outer casing has a heat-resistant resin layer as an outer layer, a metal foil layer as an intermediate layer, and a hot-melt resin layer as an inner layer, wherein the adhesive resin is a modified polyolefin with introduced functional groups.

2. The all-solid-state battery according to claim 1, wherein the area of ​​the battery cell is 0.1 cm². 2 the following.

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