Dual-structure battery

Abstract

The present invention provides a battery configuration that is resistant to both gases and liquids. [Solution] The double-structured battery 1 comprises a solid-state battery 2 having a power generation element 4 and an inner case 5 housing the power generation element 4, and an outer case 3 housing the solid-state battery 2. The inner case 5 is made of a metal material and has a bottomed cylindrical outer can 51 in which the power generation element 4 is housed and whose bottom 51a is electrically connected to the positive electrode 41, a sealing can 52 electrically connected to the negative electrode 42, and a gasket 53 that seals the outer can 51 and the sealing can 52. The outer case 3 is made of a metal material and has a bottomed cylindrical outer container portion 31 in which the solid-state battery 2 is housed and whose bottom 51a of the outer can 51 of the solid-state battery 2 is in contact, and a sealing plate 32 that covers and seals the opening of the outer container portion 31 and is in contact with the sealing can 52 so as to be electrically connected to the power generation element 4.

Description

Technical Field

[0001] The present invention relates to a dual-structure battery in which a power generation element is doubly sealed.

Background Art

[0002] In recent years, with the development of portable electronic devices such as mobile phones and notebook personal computers, and the practical application of electric vehicles, there has been an increasing need for batteries that are small and lightweight, yet have high capacity and high energy density. As such a battery, a lithium-ion battery using an organic electrolyte has been conventionally provided. However, due to the increasing demand for higher safety, recently, all-solid-state batteries using a solid electrolyte instead of a flammable organic electrolyte have been proposed.

[0003] Among them, sulfide-based solid electrolytes have attracted attention as solid electrolytes because they have high ionic conductivity and can improve the discharge characteristics of batteries, and the development of all-solid-state batteries using sulfide-based solid electrolytes has been actively promoted. However, sulfide-based solid electrolytes are likely to react with water, and when even a small amount of moisture is present in the battery, it reacts with the moisture to generate hydrogen sulfide. When hydrogen sulfide is generated inside an all-solid-state battery, problems such as increasing the internal pressure of the battery and degrading the battery characteristics, or causing deterioration of the members inside and outside the battery occur.

[0004] To solve such problems, Patent Document 1 proposes disposing a hydrogen sulfide adsorbent in the gap between the exterior body that encloses the electrode body and the electrode body. Thereby, even if moisture brought into the battery during battery assembly or moisture that has entered the battery through the sealing portion including a gasket reacts with the sulfide-based solid electrolyte to generate hydrogen sulfide, it can be efficiently captured by the hydrogen sulfide adsorbent, and the above problems can be prevented to some extent.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2023-150498 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, there is a limit to the amount of hydrogen sulfide that can be captured by the hydrogen sulfide adsorbent. Therefore, if, after the hydrogen sulfide adsorbent has lost its function, hydrogen sulfide is generated by a reaction between the sulfide-based solid electrolyte and any remaining moisture in the battery or moisture that has newly entered the battery through the sealing portion, the hydrogen sulfide adsorbent will no longer be able to treat it. As a result, when the battery is used for a long period of time, there is a risk that hydrogen sulfide will leak to the outside through the sealing portion of the battery, including the gasket.

[0007] Furthermore, even when using solid electrolytes other than sulfide-based solid electrolytes, such as hydride-based solid electrolytes, the characteristics of the battery may deteriorate due to moisture inside the battery. Therefore, it is necessary to prevent moisture from entering the inside of the battery through the sealing portion for a long period of time.

[0008] The object of the present invention is to provide a battery configuration that can prevent moisture from entering the battery for a long period of time, and also prevent gases such as hydrogen sulfide from leaking to the outside even if such gases are generated inside the battery. [Means for solving the problem]

[0009] A dual-structure battery according to one embodiment of the present invention comprises a battery body having a power generation element including a first electrode, a second electrode and an electrolyte, an inner case housing the power generation element, and an outer case housing the battery body. The inner case is made of a metal material and comprises a bottomed cylindrical outer can in which the power generation element is housed and whose bottom is electrically connected to the first electrode, a sealing can covering the opening of the outer can and electrically connected to the second electrode, and a gasket in which at least a portion is disposed between the outer can and the sealing can to seal the outer can and the sealing can. The outer case is made of a metal material and comprises a bottomed cylindrical outer container portion in which the battery body is housed and whose bottom of the outer can or the sealing can contacts the battery body, and a sealing plate covering and sealing the opening of the outer container portion and contacting the bottom of the outer can or the other of the sealing can so as to be electrically connected to the power generation element (first configuration).

[0010] In the above configuration, the battery unit is sealed by a gasket between the outer casing and the sealing casing, as well as by the outer container portion and the sealing plate. Therefore, even if the gasket is made of a material highly resistant to gases, the outer container portion and the sealing plate can prevent liquid from entering the battery unit. This makes it possible to realize a battery that is resistant to both gases and liquids.

[0011] In the first configuration described above, the pressure in the internal space of the outer case is less than atmospheric pressure (second configuration).

[0012] As a result, the outer case is pushed inward by atmospheric pressure, allowing it to be brought into close contact with the battery body. This enables a more reliable electrical connection between the outer case and the battery body.

[0013] In the second configuration described above, the sealing plate has an annular hermetic seal portion in plan view and a central electrode portion located inside the hermetic seal portion and in contact with the bottom of the outer casing or the sealing casing of the battery body (third configuration).

[0014] The hermetic seal portion can be constructed from a material with high resistance to liquids. Therefore, the above configuration prevents liquid from entering the outer case from the outside. Although the hermetic seal portion has low resistance to gases, the battery gasket prevents gases from leaking out of the battery. Therefore, a battery that is resistant to both gases and liquids can be realized.

[0015] In the third configuration described above, the bottom of the outer container portion of the outer case is in contact with the bottom of the outer casing of the battery body. The central electrode portion of the sealing plate of the outer case is in contact with the central portion of the sealing casing of the battery body in a plan view (fourth configuration).

[0016] When the pressure inside the outer case is lower than atmospheric pressure, the deformation of the central portion of the bottom of the outer container and the central portion of the sealing plate in a plan view is greater than the deformation of the outer periphery. This allows the central portion of the bottom of the outer container to be in close contact with the central portion of the bottom of the outer casing of the battery body, and the central electrode portion, which is located in the center of the sealing plate in a plan view, to be in close contact with the central portion of the sealing casing. This allows for a more reliable electrical connection between the outer case and the battery body.

[0017] In any one of the first to fourth configurations described above, the battery body is an all-solid-state battery that includes a solid electrolyte in the power generation element (fifth configuration).

[0018] While solid-state batteries do not leak, they can generate gas internally. Therefore, when the battery is a solid-state battery, the gasket is made of a material that is highly resistant to gas. However, materials that are highly resistant to gas may have low resistance to liquid. Consequently, a gasket made of a material highly resistant to gas may allow liquid to penetrate into the battery.

[0019] In contrast, in the double-structured battery with the above configuration, the battery body is further sealed by an outer container and a sealing plate. Therefore, the gasket prevents gas generated inside from leaking out, and the outer container and sealing plate prevent liquid from entering the interior. Thus, a particularly useful configuration can be provided for all-solid-state batteries in which the electrolyte is a solid electrolyte.

[0020] In the fifth configuration described above, at least a portion of the solid electrolyte is a sulfide solid electrolyte (sixth configuration).

[0021] When the solid electrolyte contains a sulfide solid electrolyte, sulfur-based gases may be generated during charging and discharging. To address this, the gasket sealing the power generation element is made of a material highly resistant to sulfur-based gases, and the battery body is sealed with an outer container and a sealing plate, thereby suppressing the ingress of liquid into the battery body. Therefore, a particularly useful configuration can be provided for all-solid-state batteries in which the solid electrolyte contains a sulfide solid electrolyte. [Effects of the Invention]

[0022] According to an exemplary embodiment of the present invention, a dual-structure battery includes a battery body having a power generation element and an inner case that houses the power generation element, and an outer case that houses the battery body. The inner case has a gasket that seals an outer can and a sealed can, and the outer case has an outer container portion and a sealing plate that covers and seals an opening of the outer container portion. With this configuration, for example, even when the gasket is made of a material highly resistant to gas, the outer container portion and the sealing plate can suppress the intrusion of liquid into the battery body. Thereby, a battery having resistance to both gas and liquid can be realized.

Brief Description of the Drawings

[0023] [Figure 1] FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a dual-structure battery according to an embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing a state in which the outer case is pushed inward by atmospheric pressure.

Embodiments for Carrying Out the Invention

[0024] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals and the description thereof will not be repeated.

[0025] In each of the drawings used in this specification, the arrangement of each component is schematically shown for explaining the mutual relationship of each component, and is different from the actual dimensional ratio and the like.

[0026] Referring to FIG. 1, an example of a dual-structure battery 1 according to an embodiment will be described. The dual-structure battery 1 has a battery body and an outer case 3 that houses the battery body. In the present embodiment, a case where the battery body housed in the outer case 3 is an all-solid-state battery 2 will be described as an example. Note that the battery body may be another type of battery as long as the outer can 51 is made of a metal material.

[0027] The all-solid-state battery 2 has a power generation element 4 and an inner case 5 that houses the power generation element 4. As described above, the all-solid-state battery 2 is housed in an outer case 3. Therefore, in the double-structure battery 1, the power generation element 4 is housed in a double case consisting of the inner case 5 and the outer case 3.

[0028] (Power generation element) The power generation element 4 is housed within the inner case 5. The power generation element 4 includes a positive electrode 41 as the first electrode, a negative electrode 42 as the second electrode, and a solid electrolyte 43. The solid electrolyte 43 is positioned between the positive electrode 41 and the negative electrode 42. The power generation element 4 is formed into a cylindrical shape by stacking the positive electrode 41, solid electrolyte 43, and negative electrode 42 in that order from the bottom 51a side (lower part of the figure) of the inner case 5. Note that the power generation element 4 is not limited to a cylindrical shape and can be changed to various shapes such as a rectangular parallelepiped or polygonal prism, depending on the size and shape of the all-solid-state battery 2. The power generation element may also have a current collector, which is not shown in the figure.

[0029] As the current collector, metal foil such as aluminum or stainless steel; sheet-like conductive porous substrates such as perforated metal, mesh, expanded metal, or foamed metal; carbon sheets; etc. are available. As the sheet-like conductive porous substrate, it is preferable to use a foamed metal porous material. A specific example of a foamed metal porous material is "Cellmet®" from Sumitomo Electric Industries, Ltd.

[0030] Positive electrode 41 is a positive electrode active material used in lithium-ion secondary batteries, with an average particle size of 3 μm, made of LiNi 0.6 Co 0.2 Mn 0.2The positive electrode pellet is formed into a cylindrical shape by placing 180 mg of a positive electrode mixture containing O2, a sulfide solid electrolyte (Li6PS5Cl), and a conductive additive, carbon nanotubes, in a mass ratio of 5:40:5 into a 10 mm diameter mold. The type of positive electrode active material used in the positive electrode 41 is not particularly limited as long as it can function as a positive electrode component of the power generation element 4. For example, materials used for the positive electrode of lithium-ion secondary batteries, such as lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt manganese composite oxide, and olivine-type composite oxide, can be used, or these may be mixed as appropriate. For example, a positive electrode molded body (pellet) formed into a cylindrical shape from a positive electrode mixture containing LCO (LiCoO2, lithium cobalt oxide), a sulfide-based solid electrolyte, and a conductive additive, carbon black, can be used as the positive electrode. Furthermore, the mass ratio of the positive electrode 41 is not limited to the above mass ratio and can be changed in various ways depending on the material. Furthermore, the size and shape of the positive electrode 41 are not limited to the size and cylindrical shape described above, but can be varied depending on the size and shape of the all-solid-state battery 2.

[0031] The negative electrode 42 is LTO(Li4Ti5O) used as a negative electrode active material in lithium-ion secondary batteries. 12 The negative electrode pellet is formed into a cylindrical shape from 300 mg of a negative electrode mixture containing lithium titanate, a sulfide solid electrolyte (Li6PS5Cl), and carbon nanotubes in a weight ratio of 50:45:5. The type of negative electrode active material used in the negative electrode 42 is not particularly limited as long as it can function as a negative electrode component of the power generation element 4. For example, materials used in the negative electrode of lithium-ion secondary batteries can be used, such as lithium titanate; metallic lithium, lithium alloys; carbon materials such as graphite and low-crystallinity carbon; oxides such as SiO2, and these may be mixed as appropriate. For example, LTO(Li4Ti5O 12A negative electrode molded body (pellet) formed into a cylindrical shape from a negative electrode mixture containing lithium titanate, a sulfide-based solid electrolyte, and carbon black as a conductive additive can be used as the negative electrode. Furthermore, the mass ratio of the negative electrode 42 is not limited to the above mass ratio and can be changed in various ways depending on the materials. Also, the size and shape of the negative electrode 42 are not limited to the above size and cylindrical shape and can be changed in various ways depending on the size and shape of the all-solid-state battery 2.

[0032] The solid electrolyte 43 can be used as a molded body (pellet) formed by shaping the solid electrolyte into a cylindrical form. The type of solid electrolyte used in the solid electrolyte 43 is not particularly limited, but for example, hydride-based solid electrolytes, sulfide-based solid electrolytes, oxide-based solid electrolytes, etc., can be used. However, from the viewpoint of ionic conductivity, sulfide-based solid electrolytes, especially argyrodite-type sulfide-based solid electrolytes, are preferred. When using a sulfide-based solid electrolyte, it is preferable to coat the surface of the positive electrode active material with a lithium-ion conductive material such as niobium oxide to prevent reaction with the positive electrode active material. Furthermore, the solid electrolytes contained in the positive electrode 21 and negative electrode 22 are not particularly limited and may be hydride-based solid electrolytes, oxide-based solid electrolytes, etc. Also, the size and shape of the solid electrolyte 43 are not limited to a cylindrical shape and can be changed in various ways depending on the size and shape of the all-solid-state battery 2.

[0033] (Inner case) The inner case 5 comprises an outer can 51, a sealing can 52, and a gasket 53. The outer can 51 is a bottomed cylindrical shape and houses the power generation element 4 inside. The outer can 51 is made of a metal material such as stainless steel, nickel, or iron.

[0034] More specifically, the outer casing 51 has a circular bottom portion 51a and a cylindrical side wall portion 51b extending from the outer circumference of the bottom portion 51a in the direction of the cylindrical axis of the outer casing 51. However, the shape of the outer casing 51 is not limited to a cylindrical shape with a circular bottom portion 51a. For example, the shape of the outer casing 51 may be formed with the bottom portion 51a in a polygonal shape such as a square, and the side wall portion 51b may be formed in a polygonal cylindrical shape such as a square cylinder that matches the shape of the bottom portion 51a, and can be changed in various ways depending on the size and shape of the all-solid-state battery 2.

[0035] In this embodiment, the positive electrode 41 of the power generation element 4 is electrically connected to the inner surface of the bottom 51a of the outer can 51. Furthermore, as will be described later, the inner surface of the bottom 31a of the outer container portion 31 of the outer case 3 is in contact with the outer surface of the bottom 51a of the outer can 51.

[0036] The opening end of the outer can 51 is curved radially inward. The opening end of the outer can 51 is crimped to the outer circumference of the sealing can 52.

[0037] The sealing can 52 covers the opening of the outer can 51, and its outer circumference is curved inward toward the outer can 51. The sealing can 52 is fitted into the opening of the outer can 51 via a gasket 53. The opening end of the outer can 51 is tightened inward, causing the gasket 53 to contact the sealing can 52, thereby sealing the opening of the outer can 51. This seals the internal space of the all-solid-state battery 2.

[0038] Furthermore, the sealing can 52 only needs to have a shape that, in plan view, can cover the opening of the outer can 51 and seal the internal space of the all-solid-state battery 2. Therefore, the plan view shape of the sealing can 52 is not limited to a circle, but may also be a polygon such as a square.

[0039] In this embodiment, the negative electrode 42 of the power generation element 4 is electrically connected to the inner surface of the sealing can 52. Also, as will be described later, the central electrode portion 322 of the sealing plate 32 in the outer case 3 is in contact with the outer surface of the sealing can 52.

[0040] The gasket 53 seals the outer can 51 and the sealing can 52. More specifically, in this embodiment, the gasket 53 is formed in a cylindrical shape along the inner circumferential surface of the side wall portion 51b of the outer can 51 and is positioned between the side wall portion 51b of the outer can 51 and the power generation element 4. As described above, a portion of the gasket 53 is sandwiched between the open end of the outer can 51 and the sealing can 52.

[0041] In this embodiment, the gasket 53 is made of a resin material such as polyphenylene sulfide (PPS). The gasket 53 is not particularly limited as long as it is made of a material that can prevent moisture from entering the inner case 5 and gas from leaking out of the inner case 5 to the outside. This prevents gas from leaking out of the inner case 5 to the outside even when gas is generated from the power generation element 4.

[0042] The gasket 53 is not particularly limited as long as it can insulate the outer can 51 and the sealing can 52. From the viewpoint of moisture permeability and heat resistance, fluororesins such as polyphenylene sulfide resin or PFA resin are preferably used. In addition, polypropylene and nylon can be used for the gasket 53, and if heat resistance is required in relation to the battery application, fluororesins such as perfluoroalkoxylene (PFA) and polytetrafluoroethylene (PTFE), and heat-resistant resins with a melting point exceeding 240°C such as polyphenylene ether (PEE), polysulfone (PSF), polyarylate (PAR), polyethersulfone (PES), polyphenylene sulfide (PPS), and polyetheretherketone (PEEK) can also be used.

[0043] (Outer case) The outer case 3 has an outer container portion 31 and a sealing plate 32. The outer container portion 31 houses the all-solid-state battery 2 inside. The outer container portion 31 is made of a metal material such as stainless steel, nickel, or iron.

[0044] More specifically, the outer container portion 31 has a circular bottom portion 31a and a cylindrical side wall portion 31b extending from the outer circumference of the bottom portion 31a in the direction of the cylindrical axis of the outer container portion 31. However, the shape of the outer container portion 31 is not limited to a cylindrical shape with a circular bottom portion 31a. For example, the shape of the outer container portion 31 may be formed with the bottom portion 31a in a polygonal shape such as a square, and the side wall portion 31b may be formed in a polygonal cylindrical shape such as a square cylinder that matches the shape of the bottom portion 31a, and can be changed in various ways depending on the size and shape of the all-solid-state battery 2.

[0045] In this embodiment, the inner surface of the bottom 31a of the outer container portion 31 is in contact with the outer surface of the bottom 51a of the outer casing 51 in the inner case 5. As described above, the positive electrode 41 of the power generation element 4 is electrically connected to the bottom 51a of the outer casing 51 of the all-solid-state battery 2. Therefore, the outer container portion 31 can function as a positive electrode casing.

[0046] The sealing plate 32 is formed in a circular, flat shape and covers the opening of the outer container portion 31. The sealing plate 32 only needs to have a shape that, in plan view, can cover the opening of the outer container portion 31 and seal the internal space of the outer case 3. Therefore, the plan view shape of the outer container portion 31 is not limited to a circle, but may be a polygon such as a square.

[0047] The sealing plate 32 has a hermetic seal portion 321, a central electrode portion 322, and an outer peripheral portion 323. The outer peripheral portion 323 is annular in plan view of the sealing plate 32. The outer peripheral side of the outer peripheral portion 323 is joined to the opening end of the outer container portion 31 by welding or the like.

[0048] The hermetic seal portion 321 is annular in the plan view. The outer circumference of the hermetic seal portion 321 is sealed to the inner circumference of the outer circumference portion 323.

[0049] In this embodiment, the hermetic seal portion 321 is made of a glassy material such as borosilicate glass or sodabarium glass. Such glassy materials have high airtightness and can prevent moisture from entering the outer case 3 from the outside.

[0050] The central electrode portion 322 is disc-shaped. The central electrode portion 322 is located in the center of the sealing plate 32 in a plan view. The outer circumference of the central electrode portion 322 is sealed to the inner circumference of the hermetic seal portion 321.

[0051] Specifically, the outer periphery 323 of the sealing plate 32 and the opening end of the outer container portion 31 are joined by welding or the like, and the outer periphery 323 and the central electrode portion 322 are joined via an annular hermetic seal portion 321. This seals the internal space of the outer case 3.

[0052] The outer surface of the central electrode portion 322 protrudes outward more than the outer surface of the outer peripheral portion 323. Furthermore, the inner surface of the central electrode portion 322 protrudes inward more than the inner surface of the outer peripheral portion 323 and contacts the central part of the sealing can 52 of the inner case 5. As described above, the negative electrode 42 of the power generation element 4 is electrically connected to the sealing can 52 of the all-solid-state battery 2. Therefore, the central electrode portion 322 can function as a negative electrode terminal. Note that the outer surface of the central electrode portion 322 does not necessarily have to protrude outward more than the outer surface of the outer peripheral portion.

[0053] As shown in Figure 2, an internal space S is formed between the all-solid-state battery 2 and the inner surface of the outer case 3. In this embodiment, the pressure in the internal space S of the outer case 3 is less than atmospheric pressure.

[0054] As a result, the outer case 3 is pushed inward by atmospheric pressure, allowing it to be brought into close contact with the solid-state battery 2. This enables a more reliable electrical connection between the outer case 3 and the solid-state battery 2.

[0055] Furthermore, in this embodiment, the bottom 31a of the outer container portion 31 in the outer case 3 is in contact with the bottom 51a of the outer casing 51 of the all-solid-state battery 2, and the central electrode portion 322 of the sealing plate 32 in the outer case 3 is in contact with the central portion of the sealing casing 52 of the all-solid-state battery 2 in a plan view.

[0056] When the pressure in the internal space S of the outer case 3 is lower than atmospheric pressure, the deformation of the central portion of the bottom 31a of the outer container portion 31 and the central portion of the sealing plate 32 in a plan view is greater than the deformation of the outer periphery. This allows the central portion of the bottom 31a of the outer container portion 31 to be in close contact with the central portion of the bottom 51a of the outer casing 51 of the all-solid-state battery 2, and the central electrode portion 322, which is located in the center of the sealing plate 32 in a plan view, to be in close contact with the central portion of the sealing casing 52. This allows for a more reliable electrical connection between the outer case 3 and the all-solid-state battery 2.

[0057] Furthermore, in the all-solid-state battery 2 configured as described above, the power generation element 4 consists of a positive electrode, a negative electrode, and an electrolyte made of solid materials. Therefore, leakage does not occur in the all-solid-state battery 2. On the other hand, gas may be generated in the all-solid-state battery 2 during charging and discharging.

[0058] In the all-solid-state battery 2, the gasket 53 is made of a material with high resistance to gas. Therefore, in the all-solid-state battery 2 of the double-structure battery 1, leakage of the gas from the inner case 5 to the outside is prevented.

[0059] Materials that are highly resistant to gases may have low resistance to liquids. Therefore, if the gasket 53 is made of a material that is highly resistant to gases, it may be difficult to prevent moisture from entering the solid-state battery 2 from the outside.

[0060] In contrast, the dual-structure battery 1 has an outer container portion 31 and a sealing plate 32 in addition to the gasket 53. Therefore, even if the gasket 53 is made of a material with high resistance to gas, the outer container portion 31 and sealing plate 32 can prevent liquid from entering the all-solid-state battery 2. Thus, a battery that is resistant to both gas and liquid can be realized.

[0061] The double-layered battery 1 according to the embodiment described above comprises a power generation element 4 including a positive electrode 41 as a first electrode, a negative electrode 42 as a second electrode, and a solid electrolyte 43, an inner case 5 housing the power generation element 4, and an outer case 3 housing the all-solid-state battery 2. The inner case 5 is made of a metal material and comprises a bottomed cylindrical outer can 51 in which the power generation element 4 is housed and whose bottom 51a is electrically connected to the positive electrode 41, a sealing can 52 that covers the opening of the outer can 51 and is electrically connected to the negative electrode 42, and a gasket 53 which is at least partially disposed between the outer can 51 and the sealing can 52 to seal the outer can 51 and the sealing can 52. The outer case 3 is made of a metal material and has a bottomed cylindrical outer container portion 31 in which the all-solid-state battery 2 is housed and the bottom 51a of the outer container 51 of the all-solid-state battery 2 is in contact, and a sealing plate 32 that covers and seals the opening of the outer container portion 31 and is in contact with the sealing container 52 so as to be electrically connected to the power generation element 4.

[0062] In the above configuration, the all-solid-state battery 2 is sealed by a gasket 53 between the outer casing 51 and the sealing casing 52, and also by the outer container portion 31 and the sealing plate 32. Therefore, even if the gasket 53 is made of a material with high resistance to gases, for example, the outer container portion 31 and the sealing plate 32 can prevent liquid from entering the all-solid-state battery 2. This makes it possible to realize a battery that is resistant to both gases and liquids.

[0063] Furthermore, while the all-solid-state battery 2 does not leak liquid, it may generate gas internally. Therefore, when the battery body housed in the outer case 3 is an all-solid-state battery 2, the gasket 53 is made of a material that is highly resistant to gas. However, materials that are highly resistant to gas may have low resistance to liquid. Consequently, with a gasket 53 made of a material that is highly resistant to gas, there is a possibility that liquid may penetrate into the all-solid-state battery 2.

[0064] In contrast, in the double-structured battery 1 with the above configuration, the all-solid-state battery 2 is further sealed by the outer container portion 31 and the sealing plate 32. Therefore, the gasket 53 prevents gas generated inside from leaking out, and the outer container portion 31 and the sealing plate 32 prevent liquid from entering the interior. Thus, a particularly useful configuration can be provided for an all-solid-state battery 2 in which the electrolyte is a solid electrolyte 43.

[0065] In this embodiment, the solid electrolyte 43 is a sulfide solid electrolyte.

[0066] When the solid electrolyte 43 contains a sulfide solid electrolyte, sulfur-based gases may be generated during charging and discharging. To address this, the gasket 53 sealing the power generation element 4 is made of a material highly resistant to sulfur-based gases, and the all-solid-state battery 2 is sealed by the outer container portion 31 and the sealing plate 32, thereby suppressing the ingress of liquid into the all-solid-state battery 2. Therefore, a particularly useful configuration can be provided for an all-solid-state battery 2 in which the solid electrolyte 43 contains a sulfide solid electrolyte.

[0067] In this embodiment, the sealing plate 32 has an annular hermetic seal portion 321 in plan view and a central electrode portion 322 located inside the hermetic seal portion 321 and in contact with the sealing can 52 of the all-solid-state battery 2.

[0068] The hermetic seal portion 321 can be made of a material with high resistance to liquids. Therefore, with the above configuration, it is possible to prevent liquid from entering the outer case 3 from the outside. The hermetic seal portion 321 has low resistance to gases, but the gasket 53 of the all-solid-state battery 2 prevents gases from leaking out of the all-solid-state battery 2. Therefore, a battery that is resistant to both gases and liquids can be realized.

[0069] (Other embodiments) Although embodiments of the present invention have been described above, the embodiments described above are merely examples for carrying out the present invention. Therefore, the invention is not limited to the embodiments described above, and it is possible to carry out the invention by appropriately modifying the embodiments described above without departing from the spirit of the invention.

[0070] The configuration of the all-solid-state battery 2 shown in each figure is just one example. The all-solid-state battery may have a different configuration.

[0071] In each figure, a gap is formed between the side wall portion 51b of the outer can 51 in the inner case 5 and the side wall portion 31b of the outer container portion 31 in the outer case 3. However, the side wall portion of the outer can in the inner case and the side wall portion of the outer container portion in the outer case may be in contact.

[0072] In the above embodiment, the positive electrode 41, which serves as the first electrode of the power generation element 4, is electrically connected to the inner surface of the bottom 51a of the outer can 51 in the inner case 5, and the negative electrode 42, which serves as the second electrode of the power generation element 4, is electrically connected to the inner surface of the sealing can 52. However, the negative electrode, which serves as the first electrode of the power generation element, may be electrically connected to the inner surface of the bottom of the outer can in the inner case, and the positive electrode, which serves as the second electrode of the power generation element, may be electrically connected to the inner surface of the sealing can.

[0073] In the above embodiment, the inner surface of the bottom 31a of the outer container portion 31 in the outer case 3 is in contact with the outer surface of the bottom 51a of the outer can 51 in the inner case 5, and the central electrode portion 322 of the sealing plate 32 in the outer case 3 is in contact with the sealing can 52 in the inner case 5. However, the inner surface of the bottom of the outer container portion in the outer case may be in contact with the sealing can of the inner case, and the central electrode portion of the sealing plate in the outer case may be in contact with the outer surface of the bottom of the outer can in the inner case. In this case, the side wall portion of the outer container portion in the outer case faces the side wall portion of the outer can in the inner case. Therefore, an insulating member having insulating properties may be placed between the side wall portion of the outer container portion and the side wall portion of the outer can.

[0074] In the above embodiment, the pressure in the internal space S of the outer case 3 is less than atmospheric pressure. However, the pressure in the internal space of the outer case may be equal to atmospheric pressure. [Industrial applicability]

[0075] This invention is applicable to all-solid-state batteries. [Explanation of Symbols]

[0076] 1 double structure battery 2 All-solid-state battery (battery body) 3. Outer case 4 Power generation elements 5. Inner case 31 Outer container part 31a bottom 31b Side wall part 32 Sealing plate 321 Hermetic seal section 322 Center electrode section 323 Outer periphery 41 Positive electrode (first electrode) 42 Negative electrode (second electrode) 43 Solid electrolyte (electrolyte) 51 Outer can 51a bottom 51b Side wall part 52 Seal can 53 Gasket S interior space

Claims

1. A battery body having a power generation element including a first electrode, a second electrode and an electrolyte, and an inner case housing the power generation element, An outer case housing the aforementioned battery, It has, The aforementioned inner case is A bottomed cylindrical outer can made of metal material, with the power generation element housed inside and its bottom electrically connected to the first electrode, A sealing can that covers the opening of the outer can and is electrically connected to the second electrode, A gasket is provided, at least a portion of which is positioned between the outer can and the sealing can, to seal the outer can and the sealing can. It has, The aforementioned outer case is A bottomed cylindrical outer container portion made of a metal material, which houses the battery body and contacts either the bottom of the outer container or the sealing container of the battery body, A sealing plate that covers and seals the opening of the outer container portion and contacts the bottom of the outer container or the other of the sealing container so as to be electrically connected to the power generation element, Having, Double structure battery.

2. A double-structured battery according to claim 1, The pressure in the internal space of the outer case is less than atmospheric pressure. Double structure battery.

3. A double-structured battery according to claim 2, The aforementioned sealing plate is In plan view, the annular hermetic seal portion, A central electrode portion located inside the hermetic seal portion and in contact with the bottom of the outer casing or the sealing casing of the battery body, Having, Double structure battery.

4. A double-structured battery according to claim 3, The bottom of the outer container portion in the outer case and the bottom of the outer casing of the battery body are in contact. In the outer case, the central electrode portion of the sealing plate is in contact with the central portion of the sealing can in the battery body in a plan view. Double structure battery.

5. A double-structured battery according to any one of claims 1 to 4, The battery body is an all-solid-state battery in which the power generation element includes a solid electrolyte. Double structure battery.

6. A double-structured battery according to claim 5, At least a portion of the solid electrolyte is a sulfide solid electrolyte. Double structure battery.

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