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

Abstract

To provide an all-solid-state battery and a method for manufacturing the same, which are less prone to misalignment of electrode stacks even when multiple electrode stacks are housed in the outer casing, and which are less prone to wrinkles in the outer casing, a concern during suction transport. [Solution] The all-solid-state battery comprises an outer casing and an electrode stack housed inside the outer casing, wherein the electrode stack has a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, and the internal pressure of the outer casing is in the range of 10 kPa to 20 kPa.

Description

[Technical Field]

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

[0002] In recent years, research and development has been conducted on rechargeable batteries that contribute to energy efficiency, in order to ensure that more people have access to affordable, reliable, sustainable, and advanced energy. Among rechargeable batteries, all-solid-state batteries are attracting attention because they have higher energy density, higher chemical stability, and a longer lifespan compared to batteries using liquid electrolytes.

[0003] All-solid-state batteries generally include an electrode stack having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive and negative electrode layers. The electrode stack is housed in an outer casing. Laminate film is used as the outer casing. The internal pressure of the outer casing is usually lower than the external pressure applied to the outer casing (Patent Document 1). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] International Publication No. 2022 / 154112 [Overview of the project] [Problems that the invention aims to solve]

[0005] Incidentally, in secondary battery technology, improving high-rate characteristics and increasing capacity are challenges. To improve the high-rate characteristics and increase capacity of all-solid-state batteries, it has been considered to reduce the thickness of the electrodes in the electrode stack to facilitate the movement of the load transfer medium, and to stack multiple such electrode stacks. However, according to the inventor's research, when multiple electrode stacks are housed in an outer casing, displacement of the electrode stacks occurs inside the casing, and concentrated surface pressure exceeding atmospheric pressure is applied to the edges of the casing, which can result in cracks forming at the edges of the electrode stacks. Furthermore, in all-solid-state battery manufacturing plants, the produced all-solid-state batteries are sometimes transported to a predetermined position by suction transport. However, with outer casings using laminate film, air remains inside the casing, making it prone to wrinkles, and if wrinkles occur in the casing, it may become impossible to transport the all-solid-state batteries by suction transport.

[0006] The present invention has been made in view of the above, and aims to provide an all-solid-state battery and a method for manufacturing the same, in which displacement of the electrode stacks is less likely to occur even when multiple electrode stacks are housed in the outer casing, and wrinkles in the outer casing, which are a concern during suction transport, are less likely to occur. This will ultimately contribute to energy efficiency. [Means for solving the problem]

[0007] The inventors of the present invention have found that adjusting the internal pressure of the outer casing to a predetermined range is effective in addressing the above-mentioned problems, and have completed the present invention. Accordingly, the present invention provides the following:

[0008] (1) A solid-state battery comprising an outer casing and an electrode stack housed inside the outer casing, wherein the electrode stack has a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, and the internal pressure of the outer casing is in the range of 10 kPa or more and 20 kPa or less.

[0009] In the case of the all-solid-state battery of (1), since the internal pressure of the casing is within the above range, displacement of the electrode stacks is unlikely to occur even when multiple electrode stacks are housed in the casing. Also, if there are wrinkles that affect suction before suction transport, suction transport may not be possible. In the case of the all-solid-state battery of (1), since the internal pressure of the casing is within the above range and the internal pressure is appropriately adjusted, when the vacuum pressure that is problematic during suction transport is reached, wrinkles due to adhesion of the laminate film on the cell surface do not occur. For this reason, suction transport is possible with the all-solid-state battery of (1).

[0010] (2) The all-solid-state battery according to (1), wherein the outer casing includes a laminate film, the laminate film having a metal layer, an inner resin layer disposed inside the metal layer, and an outer resin layer disposed outside the metal layer, and the thickness of the metal layer is within the range of 2 to 3 times the thickness of the inner resin layer.

[0011] In the case of the all-solid-state battery described in (2), the thickness of the metal layer of the laminate film contained in the outer casing is thick and has high thermal conductivity, which prevents the temperature of the electrode stack from rising and improves the battery characteristics.

[0012] (3) The all-solid-state battery according to (1) or 2, wherein the negative electrode layer has a thickness that changes with charging and discharging, and the outer casing has a flexible portion that can expand and contract in the stacking direction of the electrode stack in accordance with the change in the thickness of the negative electrode layer.

[0013] In the all-solid-state battery of (3), the outer casing has a flexible portion that can expand and contract in the stacking direction of the electrode stack in accordance with the change in the thickness of the negative electrode layer of the electrode stack, so that excessive pressure is not applied to the electrode stack, and furthermore, displacement of the electrode stack is less likely to occur.

[0014] (4) A solid-state battery according to any one of (1) to (3), wherein two or more electrode stacks are stacked inside the outer casing.

[0015] According to the all-solid-state battery of (4), since it contains two or more electrode stacks, the electrical capacity is large.

[0016] (5) The all-solid-state battery according to any one of (1) to (4), wherein a resin coat is provided on at least a part of the surface of the electrode laminate facing the exterior body.

[0017] According to the all-solid-state battery of (5), since the electrode laminate is protected by the resin coat, the electrode laminate is less likely to be damaged by external impact. In addition, the electrode laminate is less likely to be damaged during the production of the all-solid-state battery.

[0018] (6) A method for producing an all-solid-state battery, comprising: a step of accommodating an electrode laminate having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer in an exterior container having an opening; a step of degassing the interior of the exterior container under reduced pressure through the opening of the exterior container until the internal pressure of the exterior container falls within the range of 10 kPa to 20 kPa; and a step of sealing the opening of the exterior container to obtain the all-solid-state battery.

[0019] According to the method for producing an all-solid-state battery of (6), an all-solid-state battery in which the internal pressure of the exterior container is within the range of 10 kPa to 20 kPa can be produced industrially advantageously.

[0020] (7) The method for producing an all-solid-state battery according to (6), comprising a step of conveying the all-solid-state battery to a predetermined position by suction conveyance.

[0021] According to the method for producing an all-solid-state battery of (7), since the internal pressure of the exterior container of the all-solid-state battery is within the above range, there are no wrinkles that affect suction before suction conveyance. Therefore, the all-solid-state battery can be conveyed by suction conveyance. Effects of the Invention

[0022] According to the present invention, even when a plurality of electrode laminates are housed in the exterior body, the internal pressure is low, so the exterior body is pressed against the electrode laminates and acts as a fixing force for the electrode laminates, making positional displacement of the electrode laminates less likely to occur, and making wrinkles less likely to form even during suction conveyance. This makes it possible to provide an all-solid-state battery and a method for manufacturing the same. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] [Figure 1] It is a side view of an all-solid-state battery according to one embodiment of the present invention. [Figure 2] It is a plan view of an all-solid-state battery according to one embodiment of the present invention. [Figure 3] It is a cross-sectional view taken along line III-III of Figure 2. [Figure 4] It is a cross-sectional view taken along line IV-IV of Figure 2. [Figure 5] It is a partial cross-sectional view of the all-solid-state battery produced in the example. DETAILED DESCRIPTION OF EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below are illustrative of the present invention, and the present invention is not limited to the following.

[0025] Figure 1 is a side view showing the external appearance of an all-solid-state battery according to one embodiment of the present invention. Figure 2 is a plan view of the all-solid-state battery according to one embodiment of the present invention, Figure 3 is a cross-sectional view taken along line III-III of Figure 2, and Figure 4 is a cross-sectional view taken along line IV-IV of Figure 2.

[0026] The all-solid-state battery 1 includes an exterior body 60 and an electrode laminate 40 housed inside the exterior body 60. The size of the all-solid-state battery 1 may, for example, have a length in the range of 400 mm to 600 mm, a width in the range of 80 mm to 120 mm, and a thickness in the range of 3 mm to 10 mm.

[0027] The electrode stack 40 includes a positive electrode layer 10, a negative electrode layer 20, and a solid electrolyte layer 30 disposed between the positive electrode layer 10 and the negative electrode layer 20. Multiple electrode stacks 40 are stacked to form an all-solid-state battery cell 50.

[0028] The internal pressure of the outer casing 60 is set to be within the range of 10 kPa to 20 kPa. This internal pressure within the outer casing 60 ensures good adhesion between the electrode laminate 40 and the outer casing 60, acting as a fixing force that reduces misalignment between the electrode laminate 40 and the outer casing 60, and thus prevents wrinkles from forming on the outer casing.

[0029] The outer casing 60 includes two laminate films 60a and 60b. The ends of the two laminate films 60a and 60b are overlapped to form a housing portion 61 for housing the all-solid-state battery cell 50, and a sealing portion 62 is formed by fusing each of the four opposing sides.

[0030] Laminate films 60a and 60b, although not shown, have a metal layer, an inner resin layer positioned inside the metal layer, and an outer resin layer positioned outside the metal layer. For example, aluminum can be used as the material for the metal layer. For example, polyethylene, polypropylene, ethylene vinyl acetate copolymer, polyurethane, and polyethylene terephthalate can be used as the material for the inner resin layer. For example, polyimide, polyester, polycarbonate, acrylic resin, and fluororesin can be used as the material for the outer resin layer.

[0031] The thickness of the metal layer of the laminate films 60a and 60b may be in the range of 2 to 3 times the thickness of the inner resin layer. For example, the thickness of the metal layer may be in the range of 46 μm to 100 μm. For example, the thickness of the inner resin layer may be in the range of 23 μm to 35 μm. For example, the thickness of the outer resin layer may be in the range of 2 μm to 30 μm.

[0032] The outer casing 60 has a flexible portion 63 that expands and contracts in the stacking direction of the all-solid-state battery cell 50 in accordance with changes in the thickness of the negative electrode layer 20 due to charging and discharging. The flexible portion 63 is positioned along the corners of the upper and lower surfaces of the all-solid-state battery cell 50 in the stacking direction. For example, when the thickness of the negative electrode layer 20 increases due to charging, the flexible portion 63 expands in the stacking direction of the all-solid-state battery cell 50, and when the thickness of the negative electrode layer 20 decreases due to discharging, it curves.

[0033] A resin coating 70 is placed between the end face of the all-solid-state battery cell 50 on the side where the positive electrode tab 15 and negative electrode tab 25 are not located and the outer casing 60. The step difference between the stacked all-solid-state battery cells 50 is absorbed by filling the space with the resin coating 70. The resin coating 70 has the function of protecting the all-solid-state battery cell 50 from physical impact. The Young's modulus of the resin coating 70 at 25°C may be 70 MPa or less, or 40 MPa or less. The thickness of the resin coating 70 may be in the range of 0.1 mm to 1.0 mm. Polyolefin resin, acrylic resin, and silicone resin can be used as the material for the resin coating. The resin coating 70 may be placed on the end face on the side where the positive electrode tab 15 and negative electrode tab 25 are not located.

[0034] In the all-solid-state battery 1 of this embodiment, the configuration of the positive electrode layer 10, negative electrode layer 20, and solid electrolyte layer 30 included in the electrode stack 40 is not particularly limited, and those used in conventional all-solid-state batteries can be used.

[0035] The positive electrode layer 10 comprises a positive electrode current collector 11 and a positive electrode active material layer 12. The positive electrode active material layer 12 is laminated on both sides of the positive electrode current collector 11. One end of the positive electrode current collector 11 is an outwardly extended positive electrode current collector extension 11a. The positive electrode current collector extension 11a is connected to a positive electrode tab 15, which is drawn out from the outer casing 60.

[0036] Examples of materials for the positive electrode current collector 11 include aluminum, aluminum alloy, stainless steel, nickel, iron, and titanium.

[0037] As the material for the positive electrode active material layer 12, a composition containing a positive electrode active material, a conductive additive, and a binder can be used. Examples of positive electrode active materials include lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), and lithium nickel manganese cobalt oxide (NMC:LiNi p Mn q Co r O2(p+q+r=1), LiNi p Al q Co r O2 (p+q+r=1), lithium manganese (LiMn2O4), Li 1+x Mn 2-x-y Examples of heteroatom-substituted Li-Mn spinel represented by MO4 (x+y=2, M=at least one selected from Al, Mg, Co, Fe, Ni, and Zn), lithium titanate (oxide containing Li and Ti), and lithium phosphate (LiMPO4, M=at least one selected from Fe, Mn, Co, and Ni). Examples of conductive additives include carbon black, natural graphite, carbon fiber, and carbon nanotubes. Examples of binders include nitrile polymers, polyester polymers, acrylic acid polymers, cellulose polymers, styrene polymers, styrene-butadiene polymers, vinyl acetate polymers, urethane polymers, vinylidene fluoride polymers, and fluoroethylene polymers.

[0038] The negative electrode layer 20 includes a negative electrode current collector 21 and a negative electrode active material layer 22. The negative electrode active material layer 22 is laminated on both sides of the negative electrode current collector 21. The end of the negative electrode current collector 21 opposite to the positive electrode current collector extension 11a of the positive electrode current collector 11 is an outwardly extended negative electrode current collector extension (not shown). The negative electrode current collector extension is connected to a negative electrode tab 25, which is led out from the outer casing 60.

[0039] Examples of materials for the negative electrode current collector 21 include copper, copper alloys, nickel, and stainless steel.

[0040] The negative electrode active material layer 22 may be a layer that generates a lithium-containing metal layer during charging. When the negative electrode active material layer 22 generates a lithium-containing metal layer during charging, the thickness of the negative electrode layer 20 increases. As the negative electrode active material layer 22, lithium, a metal or semimetal that forms an alloy with lithium, carbon, or an oxide can be used. Examples of metals and semimetals that form alloys with lithium include Mg, Si, Au, Ag, In, Ge, Sn, Pb, Al, and Zn. Note that instead of using the negative electrode active material layer 22, the negative electrode layer 20 may be configured such that a lithium-containing metal layer is formed on the negative electrode current collector 21.

[0041] The solid electrolyte layer 30 contains a solid electrolyte. As the solid electrolyte, a sulfide solid electrolyte, an oxide solid electrolyte, a nitride solid electrolyte, or a halide solid electrolyte can be used. Examples of the sulfide solid electrolyte include Li2S-P2S5, Li2S-P2S5-LiI, and the like. The sulfide solid electrolyte may have an argyrodite-type crystal structure. Examples of the oxide solid electrolyte include NASICON-type oxides, garnet-type oxides, and perovskite-type oxides. As an example of the NASICON-type oxide, an oxide containing Li, Al, Ti, P, and O (for example, Li 1.5 Al 0.5 Ti 1.5 (PO4)3) can be cited. Examples of the garnet-type oxide include oxides containing Li, La, Zr, and O (for example, Li7La3Zr2O 12 ). Examples of the perovskite-type oxide include oxides containing Li, La, Ti, and O (for example, LiLaTiO3). The solid electrolyte layer 30 may contain a binder. Examples of the binder are the same as in the case of the positive electrode active material layer 12.

[0042] The all-solid-state battery 1 can be manufactured by a method including, for example, a housing step, a vacuum degassing step, and a sealing step. The manufactured all-solid-state battery 1 may be transported to a predetermined position by a transporting step.

[0043] The housing process involves housing the all-solid-state battery cell 50 in an outer container having an opening. The outer container having an opening can be formed using two laminate films 60a and 60b. For example, the all-solid-state battery cell 50 is placed on the inner resin layer of laminate film 60a, and then laminate film 60b is placed over it with the inner resin layer facing downwards. Next, the edges of laminate film 60a and laminate film 60b are overlapped, and three of the four opposing sides are sealed by fusion of the inner resin layers. This forms an outer container having an opening on one side.

[0044] The degassing process involves degassing the inside of the outer container containing the all-solid-state battery cells 50 through the opening of the outer container until the internal pressure of the outer container is within the range of 10 kPa to 20 kPa. Degassing can be performed, for example, by placing the outer container in a degassing chamber to remove the gas from inside, or by inserting an exhaust pipe into the opening of the outer container to remove the gas from inside.

[0045] The sealing process involves sealing the opening of the outer container. In this way, the entire outer perimeter of the laminate film 60a and laminate film 60b is sealed, forming the outer casing 60. This results in the all-solid-state battery 1.

[0046] With the all-solid-state battery 1 of this embodiment configured as described above, the internal pressure of the outer casing 60 is within the range of 10 kPa to 20 kPa, so that the all-solid-state battery cells 50 housed in the outer casing 60 are less prone to misalignment of the electrode stack 40. Furthermore, with the all-solid-state battery 1 of this embodiment, since the internal pressure of the outer casing 60 is within the above range and the internal pressure is appropriately adjusted, the laminate film on the cell surface does not wrinkle due to sticking when a vacuum pressure is applied, which is a problem during suction transport. For this reason, the all-solid-state battery 1 of this embodiment can be transported by suction.

[0047] In the all-solid-state battery 1 of this embodiment, the outer casing 60 includes laminate films 60a and 60b, each having a metal layer, an inner resin layer disposed inside the metal layer, and an outer resin layer disposed outside the metal layer. When the thickness of the metal layer is within the above range, the metal layer is thick and has high thermal conductivity, which prevents the temperature of the all-solid-state battery cell 50 from rising and improves the battery characteristics.

[0048] In the all-solid-state battery 1 of this embodiment, if the thickness of the negative electrode layer 20 fluctuates due to charging and discharging, and the outer casing 60 has a bendable portion 63 that can expand and contract in the stacking direction of the all-solid-state battery cells 50 in accordance with the change in the thickness of the negative electrode layer 20, then it is possible to suppress the application of excessive pressure to the all-solid-state battery cells 50.

[0049] In the all-solid-state battery 1 of this embodiment, if an all-solid-state battery cell 50 in which two or more electrode stacks are stacked is arranged inside the outer casing 60, the electrical capacity increases.

[0050] In the all-solid-state battery 1 of this embodiment, if a resin coating 70 is provided on at least a portion of the surface of the electrode stack 10 facing the outer casing 60, the electrode stack 10 becomes less susceptible to damage from external impacts. Furthermore, the electrode stack 10 becomes less susceptible to damage during the manufacturing of the all-solid-state battery 1.

[0051] According to the method for manufacturing an all-solid-state battery of this embodiment, by performing a vacuum degassing step to reduce the pressure until the internal pressure of the outer container is within the range of 10 kPa to 20 kPa, and then sealing the opening of the outer container in the sealing step, an all-solid-state battery having an internal pressure within the range of 10 kPa to 20 kPa can be manufactured industrially advantageously.

[0052] The all-solid-state battery obtained by the manufacturing method of this embodiment is less prone to wrinkles on the surface of the outer casing 60 (laminate films 60a, 60b), which are a concern during suction transport, because the internal pressure of the outer casing is within the above range.

[0053] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the embodiments described above, and any modifications or improvements that can achieve the objectives of the present invention are included in the present invention. For example, in this embodiment, the positive electrode active material layer 12 is arranged on both sides of the positive electrode current collector 11, but it is sufficient to arrange it on the surface on the negative electrode layer 20 side, or it may be arranged on only one side of the positive electrode current collector 11. Similarly, the negative electrode active material layer 22 is also arranged on both sides of the negative electrode current collector 21, but it is sufficient to arrange it on the surface on the positive electrode layer 10 side, or it may be arranged on only one side of the negative electrode current collector 21. Furthermore, in this embodiment, the outer casing 60 is formed by overlapping two laminate films 60a and 60b and fusing the four opposing sides, but it may also be formed by folding a single laminate film and fusing the three opposing sides. [Examples]

[0054] Next, the present invention will be described with reference to examples. However, the present invention is not limited to these examples.

[0055] [Example 1] (Fabrication of electrode stacks) A positive electrode layer, a solid electrolyte layer, and a negative electrode layer were stacked, and the resulting laminate was pressed to produce an electrode laminate. In this way, a rectangular electrode laminate with a length of 400 mm to 600 mm, a width of 80 mm to 120 mm, and a thickness of 150 μm to 250 μm was produced.

[0056] (Fabrication of all-solid-state batteries) A rectangular electrode stack, prepared as described above, was stacked to create a rectangular parallelepiped-shaped all-solid-state battery cell.

[0057] Two laminate films with a three-layer structure were prepared (first laminate film, second laminate film), each having an inner resin layer (polypropylene layer, thickness: 23 μm), an aluminum layer (thickness: 80 μm), and an outer resin layer (polyethylene terephthalate layer, thickness: 6 μm). A solid-state battery cell was placed on the inner resin of the first laminate film, and the second laminate film was placed over it with the inner resin facing downwards. As shown in Figure 5, a pressure-sensitive sheet 80 was placed on the long side of the rectangular solid-state battery cell 50. Next, the edges of the first laminate film and the second laminate film were overlapped, and three of the four opposing sides were joined by fusion of the inner resin to create an outer container with an opening on the side opposite to the side where the pressure-sensitive paper 80 was placed.

[0058] The outer container was placed in a vacuum chamber, and the inside of the container was degassed under reduced pressure until the internal pressure reached 20 kPa. At the point when the internal pressure of the outer container reached 20 kPa, the opening was fused and sealed. In this way, an all-solid-state battery was fabricated.

[0059] [Comparative Example 1] An all-solid-state battery was fabricated in the same manner as in Example 1, except that the inside of the outer container was degassed under reduced pressure until the internal pressure of the outer container was 2 kPa.

[0060] [Comparative Example 2] An all-solid-state battery was fabricated in the same manner as in Example 1, except that the inside of the outer container was degassed under reduced pressure until the internal pressure of the outer container was 80 kPa.

[0061] [evaluation] Surface pressure tests and vacuum suction tests were performed on the all-solid-state batteries prepared in Example 1 and Comparative Examples 1-2 as described below. The results are shown in Table 1 below.

[0062] (Surface pressure test) The solid-state battery was left to stand for 5 minutes. After standing, the laminate film was opened, and the pressure-sensitive paper 80 placed on the long side was removed. The pressure-sensitive paper was visually inspected to confirm the surface pressure and pressure applied to it. The results are shown in Table 1.

[0063] (Wrinkle formation) The presence or absence of wrinkles on the upper surface of the all-solid-state battery was visually inspected. The results are shown in Table 1.

[0064] [Table 1]

[0065] As shown in Table 1, the all-solid-state battery of Example 1, in which the internal pressure of the outer casing was within the range of the present invention, did not show discoloration due to localized high surface pressure in the surface pressure test, confirming the relaxation of the load on the edges of the electrode stack. Furthermore, since no wrinkles that would hinder adsorption were observed on the suction surface of the all-solid-state battery of Example 1 after degassing under reduced pressure, it was confirmed that it could be transported by suction transport.

[0066] In contrast, the all-solid-state battery in Comparative Example 1, whose internal pressure of the outer casing was lower than the range of the present invention, showed discoloration due to localized high surface pressure in the surface pressure test, confirming that excessive load was being applied to the edges of the electrode stack. The all-solid-state battery in Comparative Example 2, whose internal pressure of the outer casing was higher than the range of the present invention, showed numerous wrinkles on the suction surface after degassing, confirming that it was not suitable for transport by suction. [Explanation of symbols]

[0067] 1 All-solid-state battery 10 Positive electrode layer 11 Positive electrode current collector 11a Positive electrode current collector extension 12 Cathode active material layer 15 Positive Tab 20 Negative electrode layer 21 Negative electrode current collector 22 Negative electrode active material layer 25 Negative Electrode Tabs 30 Solid electrolyte layer 40 Electrode Stack 50 solid-state battery cells 60 Exterior 60a, 60b Laminating Film 61 Storage Unit 62 Sealing part 63. Bending section 70 Resin coating 80 pressure-sensitive paper

Claims

1. It comprises an outer casing and an electrode stack housed inside the outer casing, The electrode laminate comprises a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer. A solid-state battery in which the internal pressure of the outer casing is within the range of 10 kPa to 20 kPa.

2. The exterior body is a laminate film, The laminate film comprises a metal layer, an inner resin layer disposed inside the metal layer, and an outer resin layer disposed outside the metal layer. The all-solid-state battery according to claim 1, wherein the thickness of the metal layer is within a range of two to three times the thickness of the inner resin layer.

3. The thickness of the aforementioned negative electrode layer fluctuates due to charging and discharging. The all-solid-state battery according to claim 1 or 2, wherein the outer casing has a flexible portion that can expand and contract in the stacking direction of the electrode stack in accordance with changes in the thickness of the negative electrode layer.

4. The all-solid-state battery according to claim 1 or 2, wherein two or more electrode stacks are stacked inside the outer casing.

5. The all-solid-state battery according to claim 1 or 2, wherein at least a portion of the surface of the electrode stack facing the outer casing is provided with a resin coating.

6. A step of housing an electrode laminate having a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer in an outer container having an opening, A step of degassing the inside of the outer container by reducing the pressure inside the outer container through the opening of the outer container so that the internal pressure of the outer container is within a range of 10 kPa or more and 20 kPa or less, A method for manufacturing an all-solid-state battery, comprising the step of sealing the opening of the outer container to obtain an all-solid-state battery.

7. A method for manufacturing an all-solid-state battery according to claim 6, comprising the step of transporting the all-solid-state battery to a predetermined position by suction transport.

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