All-solid-state batteries

Abstract

To provide an all-solid-state battery that hardly expands even under reduced pressure.SOLUTION: A disclosed all-solid-state battery 100 includes at least one unit battery 120 that includes a positive electrode layer 121, a negative electrode layer 122, and a solid electrolyte layer 123. The all-solid-state battery 100 includes: a laminate 110 that includes at least one unit battery 120; a restraint member 130 that is placed to enclose the laminate 110 to restrain the laminate 110; and an exterior body 140 that seals the laminate 110 and the restraint member 130. The restraint member 130 does not seal the interior of the restraint member 130.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present disclosure relates to all-solid-state batteries. [Background technology]

[0002] Currently, all-solid-state batteries, which have high safety and energy density, are attracting attention. All-solid-state batteries include a laminate including a positive electrode layer, a solid electrolyte layer, and a negative electrode layer as a power generating element. Various proposals have been made regarding the structure and manufacturing method of all-solid-state batteries.

[0003] Claim 1 of Patent Document 1 (JP 2018-129153 A) describes an all-solid-state battery stack having two or more all-solid-state battery elements each having a negative electrode current collector layer, a negative electrode active material layer, a solid electrolyte layer, a positive electrode active material layer, and a positive electrode current collector layer stacked in this order; a current collecting member having a first plate-shaped portion, a second plate-shaped portion facing the first plate-shaped portion, and a third plate-shaped portion connecting the first plate-shaped portion and the second plate-shaped portion, wherein the cross section in the thickness direction of the first, second, and third plate-shaped portions forms a U-shape; and the current collecting member is housed in an exterior body made of a laminate film, and the third plate-shaped portion is approximately parallel to the stacking direction of the all-solid-state battery stack. the U-shaped opening is arranged so as to face the all-solid-state battery stack side, one of the plurality of negative electrode current collector layers and the plurality of positive electrode current collector layers in the all-solid-state battery stack is electrically connected to at least one of the first plate-shaped portion and the second plate-shaped portion of the current collector member via the current collector tabs of each of the plurality of current collector layers, and the first plate-shaped portion and the second plate-shaped portion of the current collector member are arranged further outward than an outermost current collector layer in the stacking direction of the all-solid-state battery stack, of the plurality of current collector layers electrically connected to the current collector member.

[0004] Claim 1 of Patent Document 2 (Patent Publication No. 6868871) describes "a secondary battery comprising an exterior and an object housed in the exterior, the object having an electrode body and a laminate pack that seals the electrode body inside, the exterior applying approximately uniform pressure to each of the front and back surfaces of the object by its elastic force, the interior of the exterior being at negative pressure, the interior of the laminate pack within the exterior being at a lower pressure than the exterior, the pressure within the laminate pack within the exterior being 1 Pa or less, and the pressure outside the laminate pack being 1000 Pa or less." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2018-129153 [Patent Document 2] Patent No. 6868871 Summary of the Invention [Problem to be solved by the invention]

[0006] When an all-solid-state battery is used under reduced pressure, the battery may expand. The expansion of the battery may cause poor contact between the electrode and the current collector, or increase the resistance in each layer, resulting in a significant decrease in battery performance. In this situation, one of the objectives of the present disclosure is to provide an all-solid-state battery that is less likely to expand even under reduced pressure. [Means for solving the problem]

[0007] One aspect of the present disclosure relates to an all-solid-state battery including at least one unit battery including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer, the all-solid-state battery also including a stack including the at least one unit battery, a restraining member disposed so as to surround the stack and restrain the stack, and an exterior body that seals the stack and the restraining member, wherein the restraining member does not seal the interior of the restraining member. [Effects of the Invention]

[0008] According to the present disclosure, there is provided a manufacturing method that can easily manufacture an all-solid-state battery that is less likely to expand even under reduced pressure. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a top view schematically illustrating an example of the all-solid-state battery according to the first embodiment. [Figure 2A] FIG. 2A is a cross-sectional view taken along line IIA-IIA in FIG. [Figure 2B] FIG. 2B is a cross-sectional view taken along line IIB-IIB in FIG. [Figure 3A] FIG. 3A is a top view schematically illustrating an example of a restraining member used in the all-solid-state battery of Embodiment 1. FIG. [Figure 3B] FIG. 3B is a cross-sectional view taken along line IIIB-IIIB in FIG. [Figure 4] FIG. 4 is a cross-sectional view schematically showing another example of the restraining member used in the all-solid-state battery of Embodiment 1. [Figure 5] FIG. 5 is a cross-sectional view schematically showing another example of the restraining member used in the all-solid-state battery of Embodiment 1. [Figure 6] FIG. 6 is a cross-sectional view schematically showing another example of the all-solid-state battery of Embodiment 1. DETAILED DESCRIPTION OF THE INVENTION

[0010] The following describes embodiments of the present disclosure using examples, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values ​​and materials may be exemplified, but other numerical values ​​and other materials may be applied as long as the invention of the present disclosure can be implemented. In this specification, the expression "numerical value A to numerical value B" includes numerical value A and numerical value B and can be read as "numerical value A or more and numerical value B or less." In the following description, when lower and upper limits of numerical values ​​related to specific physical properties or conditions are exemplified, any of the exemplified lower limits and any of the exemplified upper limits can be arbitrarily combined, as long as the lower limit is not greater than the upper limit.

[0011] (All-solid-state battery) The all-solid-state battery according to this embodiment may be referred to as "all-solid-state battery (B)" below. The all-solid-state battery (B) includes at least one unit battery including a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer. The all-solid-state battery (B) includes a stack including the at least one unit battery, a restraining member disposed so as to surround the stack and restraining the stack, and an exterior body that seals the stack and the restraining member. The stack may be referred to as "stack (S)" below. The restraining member does not seal the interior of the restraining member.

[0012] In this specification, "the exterior body seals the object" means that the exterior body with the object placed inside is sealed so that there are no gaps through which gas can pass. From one perspective, the exterior body is airtight, but the restraining member is not. By sealing the interior of the exterior body, deterioration of the unit cells can be suppressed. On the other hand, when a conventional all-solid-state battery is placed under reduced pressure, the exterior body expands, and the internal laminate also tends to expand. As a result, poor contact between the electrode and the current collector occurs, and resistance in each layer increases, which can significantly reduce battery performance.

[0013] In the all-solid-state battery (B), the laminate is restrained by a restraining member, so even if the exterior body expands under reduced pressure, the laminate can be prevented from expanding. Therefore, the all-solid-state battery (B) can exhibit high performance even under reduced pressure. Furthermore, the all-solid-state battery (B) can be used reliably for a long period of time even under reduced pressure.

[0014] The exterior body may be formed using a laminate film. By forming the exterior body using a laminate film, the weight of the battery can be reduced.

[0015] The restraining member may include a cylindrical body having a first plate-shaped portion and a second plate-shaped portion. The first and second main surfaces of the stack (S) may be pressed by the first and second plate-shaped portions, respectively. In this case, when the restraining member is present alone, the first and second plate-shaped portions may each be curved so as to have a convex shape toward the inside of the restraining member. With this configuration, the curved plate-shaped portions can press the main surfaces of the stack (S). By pressing the main surfaces of the stack (S) with the plate-shaped portions, the stack (S) can be pressurized in the stacking direction. As a result, the performance and reliability of the battery can be improved. Both ends of the cylindrical body may be open. Both ends of the cylindrical body may be capped as long as the interior of the cylindrical body is not sealed.

[0016] When curved first and second plate-shaped members are used, it is preferable to select the shape and size of the cylindrical body so that when the laminate (S) etc. (laminate and, if necessary, a buffer member etc.) is placed inside the cylindrical body, the first and second plate-shaped members are flatter than before the laminate (S) etc. is placed inside the cylindrical body. In this case, the laminate (S) etc. may be inserted into the cylindrical body while the cylindrical body is pulled outward.

[0017] The cylindrical body may include a first side wall and a second side wall connecting the first plate-shaped portion and the second plate-shaped portion, and the first side wall and the second side wall may each have elasticity in the direction connecting the first plate-shaped portion and the second plate-shaped portion. In this configuration, the elasticity of the side walls can be used to allow the plate-shaped portion to strongly press against the main surface of the laminate (S). Examples of elastic side walls include side walls that are curved like leaf springs. In this case, the cylindrical body is preferably made of metal. Other examples of elastic side walls include side walls made of an elastic material such as rubber.

[0018] The cylindrical body may be made of metal. By using a cylindrical body made of metal, it is possible to press the main surface of the laminate (S) with a strong force.

[0019] The all-solid-state battery (B) may further include a buffer member disposed between the restraining member and the stack. By using the buffer member, it is possible to prevent impact from being applied to the stack. Furthermore, by using the buffer member, it is possible to make uniform the pressure applied to the stack (S) by the restraining member.

[0020] The buffer member may be a member that expands under reduced pressure. For example, the buffer member may include a foam. By using a buffer member that expands under reduced pressure, it is possible to suppress the expansion of the laminate (S) under reduced pressure.

[0021] The inside of the exterior body may be reduced in pressure. By reducing the pressure inside the exterior body, expansion of the battery and the laminate (S) under reduced pressure can be suppressed. The inside of the exterior body may be reduced in pressure to 2000 Pa or less, 1000 Pa or less, 100 Pa or less, 10 Pa or less, 1.0 Pa or less, or 0.1 Pa or less.

[0022] (Components of all-solid-state batteries) Examples of components of the all-solid-state battery (B) are described below. However, the following components are merely examples, and other components may be used. Note that, although the following mainly describes an example in which the laminate (S) is a laminate of an all-solid-state lithium ion battery, it may also be a laminate of other all-solid-state batteries. The laminate (S) is not particularly limited, and may also be a laminate of a known all-solid-state battery.

[0023] As described above, the all-solid-state battery includes a laminate (S). The laminate (S) includes at least one unit cell (power generating element). The laminate (S) may include only one unit cell, or may include multiple stacked unit cells. The unit cell includes a positive electrode layer, a negative electrode layer, and a solid electrolyte layer disposed between the positive electrode layer and the negative electrode layer. The laminate (S) includes a current collector as needed. In an all-solid-state battery, it is preferable that the laminate (S) is pressurized in its stacking direction. Pressurizing the laminate (S) enables it to exhibit high performance. The planar shape of the laminate (S) is, for example, rectangular.

[0024] (Restraining member) As described above, the restraining member can be made of metal or the like. Examples of metal plates that make up the restraining member include stainless steel plates, carbon steel plates, and aluminum alloy plates. Alternatively, the restraining member may be made of resin. Relatively hard resins such as polyethylene terephthalate resin (PET resin), epoxy resin (EP), polyether ketone ketone (PEEK), polyimide (PI), and polyamide (PA) are preferably used as the resin.

[0025] The restraining member has a size that allows the stack (S) and the like to be placed inside. The restraining member preferably has a size that allows the entire stack (S) to be placed inside. When the planar shape of the stack (S) is rectangular, the planar shape of the internal space of the restraining member is preferably also rectangular. The thickness of the metal plate constituting the restraining member may be selected depending on the material, the required pressure resistance, and the material of the metal plate. The thickness of the metal plate constituting the restraining member may be 0.10 mm or more, or 0.15 mm or more, or may be 0.60 mm or less, or 0.50 mm or less.

[0026] (exterior body) It is preferable to use a film capable of maintaining internal airtightness for a long period of time as the laminate film constituting the exterior body. Therefore, it is preferable that the laminate film includes a metal layer. Examples of the metal layer include an aluminum layer (e.g., an aluminum vapor deposition layer, an aluminum foil, etc.). The laminate film includes a resin layer. The laminate film may include a layer for heat sealing on its surface. The laminate film may be a known laminate film used for battery exterior bodies.

[0027] The exterior body may be formed using any material other than a laminate film. A known exterior body used as an exterior body for an all-solid-state battery may be used. For example, an exterior body formed using at least one of a metal, a plate-shaped resin or resin composition, a sealing member, etc. may be used. For example, the exterior body may be formed from a metal, or may be formed from a metal case and another member (e.g., a sealing member). The use of an exterior body including a metal case can prevent the exterior body from expanding under reduced pressure. In either case, the exterior body seals the interior.

[0028] (Buffer material) Examples of the buffer material include an elastic material and a material that expands under reduced pressure. An example of the elastic material is rubber. An example of the material that expands under reduced pressure is a foam. An example of the foam is a resin foam that has many small closed cells inside.

[0029] (positive electrode layer) The positive electrode layer contains a positive electrode active material and may contain other components as needed. Examples of the other components include known components (binders, conductive materials, etc.) used in the positive electrode layer of all-solid-state batteries. From the viewpoint of enhancing the lithium ion conductivity in the positive electrode layer, the positive electrode layer may contain a solid electrolyte exhibiting lithium ion conductivity together with the positive electrode active material. Typically, the positive electrode active material is used in the form of particles (powder).

[0030] The positive electrode active material can be any material that can be used as a positive electrode active material in an all-solid-state battery. In the case of an all-solid-state lithium-ion battery, examples of the positive electrode active material include lithium-containing composite oxides and compounds other than oxides. Examples of lithium-containing composite oxides include lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, and other lithium-containing composite oxides (LiNi 0.8 Co 0.15 Al 0.05 Examples of compounds other than oxides include olivine-based compounds (LiMPO4, etc.) and sulfur-containing compounds (LiS, etc.). In the above formula, M represents a transition metal. The positive electrode active material may be used alone or in combination of two or more.

[0031] (negative electrode layer) The negative electrode layer contains a negative electrode active material and may contain other components as needed. Examples of the other components include known components (binders, conductive materials, etc.) used in the negative electrode layer of all-solid-state batteries. The negative electrode layer may contain a negative electrode active material and a solid electrolyte exhibiting lithium ion conductivity. Typically, the negative electrode active material is used in the form of particles (powder).

[0032] The negative electrode active material may be a material that can be used as a negative electrode active material for all-solid-state batteries. In the case of all-solid-state lithium-ion batteries, the negative electrode active material may be a specific material (such as a carbonaceous material, a metal or semimetal element, alloy, or compound) that can reversibly absorb and release lithium ions. Examples of carbonaceous materials include graphite (natural graphite, artificial graphite, etc.), hard carbon, and amorphous carbon. Examples of metal or semimetal element or alloy include lithium metal or alloy, and elemental silicon. Examples of compounds include oxides (such as titanium oxide and silicon oxide), sulfides, nitrides, hydrates, and silicides (such as lithium silicide). The negative electrode active material may be used alone or in combination of two or more. For example, silicon oxide and a carbonaceous material may be used in combination. Particles containing graphite particles and amorphous carbon coating the graphite particles may also be used as the negative electrode active material.

[0033] (Solid electrolyte layer) The solid electrolyte layer is disposed between the positive electrode layer and the negative electrode layer. The solid electrolyte layer contains a solid electrolyte and may contain other components as needed. Examples of the other components include known components used in the solid electrolyte layer of an all-solid-state battery. The solid electrolyte is usually used in the form of particles (powder).

[0034] The solid electrolyte can be any material that can be used as a solid electrolyte in an all-solid-state battery, without any particular restrictions. In the case of an all-solid-state lithium-ion battery, the solid electrolyte can be a substance that has lithium ion conductivity. Examples of such solid electrolytes include inorganic solid electrolytes such as sulfides (sulfide-based solid electrolytes) and hydrides (hydride-based solid electrolytes).

[0035] Examples of sulfides include Li2S-SiS2, Li2S-P2S5, Li2S-GeS2, Li2S-B2S3, Li2S-Ga2S3, Li2S-Al2S3, Li2S-GeS2-P2S5, Li2S-Al2S3-P2S5, Li2S-P2S3, Li2S-P2S3-P2S5, LiX-Li2S-P2S5, LiX-Li2S-SiS2, LiX-Li2S-B2S3 (X: I, Br, or Cl), etc. Examples of hydrides include LiBH4-LiI-based complex hydrides and LiBH4-LiNH2-based complex hydrides, etc.

[0036] (Positive electrode current collector) A positive electrode current collector is usually disposed on the outside of the positive electrode layer. The positive electrode current collector may be a metal foil. Examples of materials for the positive electrode current collector (e.g., metal foil) include aluminum, magnesium, stainless steel, titanium, iron, cobalt, zinc, tin, or alloys thereof. Lead tabs are connected to the positive electrode current collector and the negative electrode current collector as needed.

[0037] (Negative electrode current collector) A negative electrode current collector is usually disposed on the outside of the negative electrode layer. The negative electrode current collector may be a metal foil. Examples of materials for the negative electrode current collector (e.g., metal foil) include copper, nickel, stainless steel, titanium, and alloys thereof.

[0038] (Manufacturing method of all-solid-state battery (B)) The method for producing the all-solid-state battery (B) is not particularly limited. An example of the method for producing the all-solid-state battery (B) will be described below. This production method includes steps (i) and (ii) in this order. These steps will be described below.

[0039] Step (i) is a step of placing the laminate (S) inside the restraining member. At that time, the restraining member is pulled outward as needed to place the laminate (S). In step (i), a buffer member is placed inside the restraining member together with the laminate (S), as needed.

[0040] Step (ii) is a step of sealing the restraining member and the object placed inside it (including at least the laminate (S), and optionally a cushioning material, etc.) with an exterior body. For example, the restraining member may be wrapped in a laminate film and then bonded at the required locations. There are no limitations on the method for bonding the laminate film, and heat sealing, etc. may be used. If necessary, heat sealing is performed so that a lead tab, etc., protrudes from the exterior body. If the inside of the exterior body is to be depressurized, step (ii) may be performed under reduced pressure. Alternatively, the inside of the exterior body may be evacuated when sealing the exterior body.

[0041] In this manner, the all-solid-state battery (B) can be manufactured. The laminate (S) may be one that has already been formed, or may be formed. There is no particular limitation on the method for forming the laminate (S), and it may be formed by a known method. The laminate (S) is preferably formed using a material that does not contain a liquid component. An example of a method for forming the laminate (S) by such a formation method (dry formation method) will be described below.

[0042] First, the materials for the positive electrode layer, the solid electrolyte layer, and the negative electrode layer are stacked in a predetermined order on a metal foil (current collector), and then a current collector (metal foil) is placed on top. Next, the stacked materials and metal foil are pressed together (main press) to form a laminate (S). This main press integrates the metal foil and each layer to obtain the laminate (S). The pressure of the main press can be adjusted appropriately depending on the material and thickness, and may be 50 MPa or more and 5000 MPa or less (e.g., 300 MPa or more and 3000 MPa or less). In this manner, a laminate (S) having a structure of positive electrode current collector / positive electrode layer / solid electrolyte layer / negative electrode layer / negative electrode current collector is obtained. Note that the laminate (S) may also include layers other than these layers, such as a thin conductive layer.

[0043] The materials may be preliminarily pressed at any stage after disposing the material for the positive electrode layer, disposing the material for the solid electrolyte layer, or disposing the material for the negative electrode layer. The preliminarily pressed is usually performed at a pressure lower than the pressure used for the main press. The preliminarily pressed pressure is not particularly limited and may be in the range of 1 MPa to 10 MPa. In order to reduce voids in the laminate, at least a part of the process of forming the laminate may be performed under reduced pressure.

[0044] By forming the laminate (S) using a process of pressing materials that do not contain liquid components, it is possible to obtain an all-solid-state battery that exhibits high performance without applying high pressure. As a method for arranging materials that do not contain liquid components (dispersion medium) in layers, electrostatic spraying, squeegee film formation, electrostatic painting, etc. may also be used.

[0045] When the laminate (S) includes a plurality of unit batteries, a laminate including one unit battery may be formed by press molding, and then these laminates may be stacked to form the laminate (S). Alternatively, the laminate (S) may be formed by press molding the materials so that a plurality of unit batteries are stacked.

[0046] Examples of embodiments according to the present disclosure will be described below with reference to the drawings. The embodiments described below may be modified based on the above description. Furthermore, the matters described below may be applied to the above embodiments. Note that the following drawings are schematic diagrams and are not drawn to actual scale. In the following drawings, some components may be omitted to make the drawings easier to see.

[0047] (Embodiment 1) A top view of the all-solid-state battery 100 of Embodiment 1 is shown schematically in Fig. 1. A cross-sectional view taken along line IIA-IIA in Fig. 1 is shown in Fig. 2A, and a cross-sectional view taken along line IIB-IIB in Fig. 1 is shown in Fig. 2B.

[0048] The all-solid-state battery 100 includes a laminate 110, a restraining member 130, and an exterior body 140. The laminate 110 includes a positive electrode current collector 111, a negative electrode current collector 112, and a unit battery 120 disposed therebetween. The unit battery 120 includes a positive electrode layer 121, a negative electrode layer 122, and a solid electrolyte layer 123 disposed therebetween. The laminate 110 has a laminated structure in which the positive electrode current collector 111, the positive electrode layer 121, the solid electrolyte layer 123, the negative electrode layer 122, and the negative electrode current collector 112 are stacked in this order along a stacking direction SD.

[0049] A positive electrode lead tab 111a protrudes from the positive electrode current collector 111. A negative electrode lead tab 112a protrudes from the negative electrode current collector 112. The positive electrode lead tab 111a may be integral with the positive electrode current collector 111, or may be a lead tab connected to the positive electrode current collector 111. The negative electrode lead tab 112a may be integral with the negative electrode current collector 112, or may be a lead tab connected to the negative electrode current collector 112.

[0050] In the first embodiment, an example in which the exterior body 140 is formed of a laminate film will be described. The exterior body 140 of the example shown in the first embodiment is formed by bonding the four sides of two rectangular laminates together. The four sides can be bonded together by, for example, heat sealing. The interior of the exterior body 140 is sealed. The interior of the exterior body 140 may be depressurized. Note that the form of the exterior body 140 is not limited to the form shown in FIG. 1 as long as the interior can be sealed.

[0051] The restraint member 130 is composed of a first plate-shaped portion 131, a second plate-shaped portion 132, a first side wall 133, and a second side wall 134. The first and second side walls 133 and 134 connect the first plate-shaped portion 131 and the second plate-shaped portion 132. The first plate-shaped portion 131 faces the first main surface 110a of the laminate 110, and the second plate-shaped portion 132 faces the second main surface 110b of the laminate 110. The first and second plate-shaped portions 131 and 132 can press the first main surface 110a and the second main surface 110b toward the inside of the laminate 110.

[0052] The restraining member 130 is made of metal or the like. The restraining member 130 has a rectangular cylindrical shape. FIG. 3A shows a cross-sectional view of the restraining member 130 when it is alone. FIG. 3B shows a cross-section taken along line IIIB-IIIB in FIG. 3A, i.e., a cross-section perpendicular to the direction LD in which the rectangular tube extends. The state in which the restraining member 130 is alone means that no other members exist inside or outside the restraining member 130, and no external force is applied to the restraining member 130. The restraining member 130 shown in FIG. 3B has a rectangular cross-section.

[0053] A cross-sectional view of another example of the restraint member 130 when it is present alone is shown in Fig. 4, and a cross-sectional view of yet another example of the restraint member 130 when it is present alone is shown in Fig. 5. Their top views are the same as the top view shown in Fig. 3A. Figs. 4 and 5 show cross sections perpendicular to the direction LD in Fig. 3A. Figs. 4 and 5 also show the outline of the stack 110 disposed inside.

[0054] 4 and 5, the first plate-shaped portion 131 and the second plate-shaped portion 132 are each curved to have a convex shape toward the inside of the restraint member 130. More specifically, the first plate-shaped portion 131 and the second plate-shaped portion 132 are curved so that central portions 131c and 132c of the first plate-shaped portion 131 and the second plate-shaped portion 132 in the width direction WD are located on the innermost side. The distance between central portions 131c and 132c is shorter than the thickness of the laminate 110.

[0055] When stack 110 and the like are placed inside restraint member 130, the shape of first plate-shaped portions 131 and 132 becomes flatter than the shape when restraint member 130 exists alone. As a result, first plate-shaped portions 131 and 132 can apply higher pressure to first and second main surfaces 110a and 110b of stack 110.

[0056] In the restraining member 130 shown in FIG. 5, not only the first plate-shaped portion 131 and the second plate-shaped portion 132 but also the first side wall 133 and the second side wall 134 are curved to have a convex shape toward the inside of the restraining member 130. Such first side wall 133 and second side wall 134 function as leaf springs that are elastic in direction D connecting the first plate-shaped portion 131 and the second plate-shaped portion 132. Therefore, the first plate-shaped portions 131 and 132 of the restraining member 130 shown in FIG. 5 can apply particularly high pressure to the first and second main surfaces 110a and 110b of the laminate 110. The shapes of the first side wall 133 and the second side wall 134 may be shapes other than those shown in FIGS. 4 and 5 and may be shapes that are elastic in direction D.

[0057] 4 and 5, stacked body 110 and the like may be placed inside restraining member 130 while restraining member 130 is pulled outward. For example, central portions 131c and 132c may be attracted by vacuum suction or the like and pulled outward.

[0058] As described above, the all-solid-state battery 100 may further include a buffer member. FIG. 6 shows a cross-sectional view of an example of the all-solid-state battery 100 including the buffer member 150. FIG. 6 is a cross-sectional view taken at the same position as the cross-sectional view of FIG. 2A. In the example shown in FIG. 6, the buffer member 150 is disposed between the restraining member 130 and the laminate 110. The planar shape of the buffer member 150 is substantially the same as the planar shape of the first main surface 110a. The all-solid-state battery 100 may include a buffer member 150 disposed between the first main surface 110a and the first plate-shaped portion 131, and a buffer member 150 disposed between the second main surface 110b and the second plate-shaped portion 132.

[0059] (Addendum) The above description discloses the following invention examples. (Example 1) An all-solid-state battery including at least one unit cell including 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 stack including the at least one unit battery; a restraining member that is arranged to surround the stack and restrains the stack; an exterior body that seals the laminate and the restraint member, an all-solid-state battery, wherein the restraining member does not seal the inside of the restraining member; (Example 2) The all-solid-state battery according to Example 1, wherein the exterior body is formed using a laminate film. (Example 3) the restraint member includes a tubular body having a first plate-shaped portion and a second plate-shaped portion, The all-solid-state battery according to Invention Example 1 or 2, wherein the first main surface and the second main surface of the laminate are pressed by the first plate-shaped portion and the second plate-shaped portion, respectively. (Example 4) In a state where the restraining member is present alone, the first plate-shaped portion and the second plate-shaped portion are each curved to have a convex shape facing inward of the restraining member. (Example 5) the cylindrical body includes a first side wall and a second side wall connecting the first plate-shaped portion and the second plate-shaped portion, The all-solid-state battery according to Invention Example 3 or 4, wherein the first side wall and the second side wall each have elasticity in a direction connecting the first plate-shaped portion and the second plate-shaped portion. (Example 6) The all-solid-state battery according to any one of Examples 3 to 5, wherein the cylindrical body is made of metal. (Example 7) The all-solid-state battery according to any one of Examples 1 to 6, further comprising a buffer member disposed between the restraining member and the laminate. (Example 8) The all-solid-state battery according to Example 7, wherein the buffer member is a member that expands under reduced pressure. (Example 9) The all-solid-state battery according to Example 8, wherein the cushioning member includes a foam. (Example 10) The all-solid-state battery according to any one of Examples 1 to 9, wherein the inside of the exterior body is depressurized. [Industrial Applicability]

[0060] The present disclosure can be used in all-solid-state batteries. [Explanation of symbols]

[0061] 100: All-solid-state battery 110: Laminate 110a: second main surface 110b: second main surface 120: Unit battery 121: Positive electrode layer 122: Negative electrode layer 123: Solid electrolyte layer 130: Restraining member 131: First plate-shaped portion 132: Second plate-shaped portion 133: First side wall 134: Second side wall 140: Exterior body 150: Cushioning material

Claims

1. An all-solid-state battery including at least one unit cell including 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 stack including the at least one unit battery; a restraining member that is arranged to surround the stack and restrains the stack; an exterior body that seals the stack and the restraining member; a buffer member disposed between the restraining member and the stack, The restraining member does not seal the interior of the restraining member, The buffer member is a member that expands under reduced pressure.

2. The all-solid-state battery according to claim 1 , wherein the exterior body is formed using a laminate film.

3. the restraint member includes a tubular body having a first plate-shaped portion and a second plate-shaped portion, The all-solid-state battery according to claim 1 or 2, wherein a first main surface and a second main surface of the laminate are pressed by the first plate-shaped portion and the second plate-shaped portion, respectively.

4. 4. The all-solid-state battery according to claim 3, wherein when the restraining member is present alone, the first plate-shaped portion and the second plate-shaped portion are each curved so as to have a convex shape facing an inside of the restraining member.

5. the cylindrical body includes a first side wall and a second side wall connecting the first plate-shaped portion and the second plate-shaped portion, The all-solid-state battery according to claim 3 , wherein the first side wall and the second side wall each have elasticity in a direction connecting the first plate-shaped portion and the second plate-shaped portion.

6. The all-solid-state battery according to claim 3 , wherein the cylindrical body is made of a metal.

7. The all-solid-state battery according to claim 1 , wherein the buffer member includes a foam.

8. The all-solid-state battery according to claim 1 or 2, wherein the inside of the exterior body is depressurized.

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