Energy storage device, lid, method for manufacturing an energy storage device

Abstract

This power storage device is provided with an electrode body and an outer package in which the electrode body is sealed. The outer package has: an outer package film that wraps the electrode body; and a lid member that seals the electrode body together with the outer package film. The lid member has a covering body and a lid main body that is composed of a metal material and is joined to the covering body. The outer package has a sealing part in which the outer package film is sandwiched between the covering body and the lid main body.

Description

[Technical Field]

[0001] The present invention relates to an electricity storage device, a lid, and a method for manufacturing an electricity storage device. [Background Art]

[0002] Patent Document 1 discloses an example of an electricity storage device. This electricity storage device includes an electrode assembly and an exterior body that seals the electrode assembly. The exterior body includes an exterior film wrapping the electrode assembly and a lid joined to the exterior film. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 2022-123686 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the aforementioned electricity storage device, if the bonding strength between the exterior film and the lid is low, the exterior film may peel off from the lid. When the exterior film peels off from the lid, the sealing performance of the electricity storage device decreases.

[0005] An object of the present invention is to provide an electricity storage device with high sealing performance, a lid used in the electricity storage device, and a method for manufacturing the electricity storage device. [Means for Solving the Problem]

[0006] The electricity storage device according to a first aspect of the present invention includes an electrode assembly and an exterior body that seals the electrode assembly. The exterior body includes an exterior film wrapping the electrode assembly and a lid that seals the electrode assembly together with the exterior film. The lid includes a covering member and a lid main body joined to the covering member. The exterior body has a sealing portion in which the exterior film is sandwiched between the covering member and the lid main body.

[0007] A power storage device according to a second aspect of the present invention is a power storage device according to a first aspect, wherein the sealing portion has a crimped portion in which the covering body and the lid body are crimped together.

[0008] A third aspect of the present invention relates to a power storage device according to the first or second aspect, wherein the covering has a first main body and a first protrusion protruding from the first main body, the lid body has a second main body and a second protrusion protruding from the second main body, and the sealing portion is formed by folding the outer film while it is sandwiched between the first and second protrusions.

[0009] A power storage device according to the fourth aspect of the present invention is a power storage device according to any one of the first to third aspects, and has an adhesion assisting member disposed between the covering body and the lid body.

[0010] A fifth aspect of the present invention relates to an energy storage device comprising an electrode body and an outer casing for sealing the electrode body, wherein the outer casing has an outer film that encloses the electrode body, a lid that seals the electrode body together with the outer film, and a sealing portion that is sealed by crimping the outer film and the lid together.

[0011] A lid according to a sixth aspect of the present invention is a lid used as an exterior body for an energy storage device, comprising a covering body and a lid body made of a metal material and joined to the covering body, wherein an exterior film constituting the exterior body is sandwiched between the covering body and the lid body.

[0012] A method for manufacturing an energy storage device according to a seventh aspect of the present invention comprises an electrode body and an outer casing for sealing the electrode body, wherein the outer casing has an outer film that encloses the electrode body and a lid that seals the electrode body together with the outer film, and the lid has a covering and a lid body that is joined to the covering. The method for manufacturing the energy storage device includes a step of forming a sealing portion in which the outer film is sandwiched between the covering and the lid body. Effects of the Invention

[0013] According to the electricity storage device, the lid body, and the method for manufacturing an electricity storage device of the present invention, high sealing performance is achieved. Brief Description of the Drawings

[0014] [Figure 1] 1 is a perspective view of the electricity storage device according to the embodiment. [Figure 2] 2 is a cross-sectional view showing an example of the layer configuration of an exterior film included in the electricity storage device of FIG. 1. [Figure 3] 3 is a view showing the exterior film included in the electricity storage device of FIG. 1 in an unfolded state. [Figure 4A] 4A is a perspective view of a covering body included in the electricity storage device of FIG. 1. [Figure 4B] 4B is a cross-sectional view taken along line D4B-D4B in FIG. 4A. [Figure 5] 5 is a perspective view of a lid main body included in the electricity storage device of FIG. 1. [Figure 6] 6 is a front view of the electricity storage device of FIG. 1. [Figure 7] 7 is a cross-sectional view taken along line D7-D7 in FIG. 1. [Figure 8] 8 is a flow chart showing an example of the method for manufacturing the electricity storage device of FIG. 1. [Figure 9] 9 is a perspective view of a lid main body included in an electricity storage device of a first modification. [Figure 10] 10 is a cross-sectional view of the electricity storage device of the first modification. [Figure 11] 11 is a cross-sectional view of an electricity storage device of a second modification. [Figure 12] 12 is a cross-sectional view of an electricity storage device of a third modification. [Figure 13] 13 is a cross-sectional view of an electricity storage device of a fourth modification. [Figure 14] 14 is a cross-sectional view of an electricity storage device of a sixth modification. [Figure 15] 15A is a cross-sectional view showing an example of the layer configuration of an exterior film included in an electricity storage device of a seventh modification. [Figure 16] 15B is a perspective view of a lid main body included in the electricity storage device of the seventh modification. [Figure 17] A cross-sectional view showing an example of the layer configuration of an exterior film included in an electricity storage device according to an eighth modification. [Figure 18] A cross-sectional view showing an example of the layer configuration of an exterior film included in an electricity storage device according to another modification of the eighth modification. [Figure 19] A cross-sectional view showing an example of the layer configuration of an exterior film included in an electricity storage device according to still another modification of the eighth modification. MODES FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, an electricity storage device according to an embodiment of the present invention will be described with reference to the drawings. In the present specification, a numerical range indicated by "~" means "not less than" and "not more than". For example, the notation 2 to 15 mm means not less than 2 mm and not more than 15 mm.

[0016] [1. Embodiment] <1-1. Configuration of Electricity Storage Device> FIG. 1 is a perspective view schematically showing an electricity storage device 10 according to an embodiment. FIG. 2 is a cross-sectional view showing an example of the layer configuration of an exterior film 50 included in the electricity storage device 10 of FIG. 1. FIG. 3 is a view showing the exterior film 50 included in the electricity storage device 10 of FIG. 1 in an unfolded state. FIG. 4A is a perspective view of a covering body 70 included in the electricity storage device 10 of FIG. 1. FIG. 4B is a cross-sectional view taken along line D4B-D4B in FIG. 4A. FIG. 5 is a perspective view of a lid main body 80 included in the electricity storage device 10 of FIG. 1. FIG. 6 is a front view of the electricity storage device 10 of FIG. 1. FIG. 7 is a cross-sectional view taken along line D7-D7 in FIG. 6. In FIG. 1, the direction of arrow UD indicates the thickness direction of the electricity storage device 10, the direction of arrow LR indicates the width direction of the electricity storage device 10, and the direction of arrow FB indicates the depth direction of the electricity storage device 10. The direction indicated by each of the arrows UD, LR, and FB is common in all subsequent drawings.

[0017] The energy storage device 10 comprises an electrode body 20 and an outer casing 40. The electrode body 20 includes electrodes (positive and negative electrodes) and separators that constitute energy storage components such as lithium-ion batteries, capacitors, all-solid-state batteries, semi-solid-state batteries, pseudo-solid-state batteries, polymer batteries, all-resin batteries, lead-acid batteries, nickel-metal hydride batteries, nickel-cadmium batteries, nickel-iron batteries, nickel-zinc batteries, silver oxide-zinc batteries, metal-air batteries, polyvalent cation batteries, or capacitors. In this embodiment, the shape of the electrode body 20 is substantially rectangular parallelepiped. Note that "substantially rectangular parallelepiped" includes not only a perfect rectangular parallelepiped but also a solid that can be considered a rectangular parallelepiped by modifying the shape of a part of its outer surface, for example. The shape of the electrode body 20 may be, for example, a cylinder or a polygonal prism.

[0018] The outer casing 40 seals the electrode body 20. The outer casing 40 comprises an outer film 50 and a lid 60. In this embodiment, the outer film 50 is wrapped around the electrode body 20. Alternatively, the electrode body 20 may be housed inside the outer film 50, which is configured in a cylindrical shape. The outer casing 40 has a pair of first surfaces 41A, 41B and a pair of second surfaces 42A, 42B. In this embodiment, the pair of first surfaces 41A, 41B are substantially the same size. In this embodiment, the pair of second surfaces 42A, 42B are substantially the same size. The area of ​​the pair of first surfaces 41A, 41B is larger than that of the pair of second surfaces 42A, 42B. The pair of lids 60 are positioned on the sides of the electrode body 20.

[0019] For example, one method involves forming a recess in the outer film 50 to accommodate the electrode body 20 through cold forming. However, forming a deep recess by such a method is not always easy. If one attempts to form a deep recess (for example, a forming depth of 15 mm) by cold forming, pinholes or cracks may occur in the outer film 50, which is likely to lead to a decrease in battery performance. On the other hand, the outer body 40 seals the electrode body 20 by wrapping the outer film 50 around the electrode body 20, so the electrode body 20 can be easily sealed regardless of its thickness. Furthermore, in order to reduce the dead space between the electrode body 20 and the outer film 50 in order to improve the volumetric energy density of the energy storage device 10, it is preferable that the outer film 50 is wrapped so as to be in contact with the outer surface of the electrode body 20. In addition, in all-solid-state batteries, it is necessary to eliminate the space between the electrode body 20 and the outer film 50 from the viewpoint that high pressure must be applied uniformly from the outside of the battery in order to achieve battery performance, so it is preferable that the outer film 50 is wrapped so as to be in contact with the outer surface of the electrode body 20.

[0020] As shown in Figure 2, the outer film 50 is a laminate (laminate film) having, for example, a base layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in that order. Note that the outer film 50 does not necessarily need to include all of these layers; for example, the barrier layer 52 may be omitted. That is, the outer film 50 only needs to be made of a flexible and easily bendable material, such as a resin film. It is preferable that the outer film 50 is heat-sealable. The innermost and outermost layers of the outer film 50 may be the heat-sealable resin layer 53. In this case, the outer film 50 may enclose the electrode body 20 and the lid 60 by joining the outermost and innermost layers.

[0021] The overall thickness of the outer film 50 can be arbitrarily selected. From the viewpoint of strength, it is preferable that the thickness of the outer film 50 be 50 μm or more. 。

[0022] The base layer 51 included in the outer film 50 is a layer that imparts heat resistance to the outer film 50 and suppresses the occurrence of pinholes that may occur during processing or distribution. The base layer 51 is composed of, for example, at least one stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one stretched polyester resin layer and a stretched polyamide resin layer in the base layer 51, the barrier layer 52 can be protected during processing of the outer film 50, and the breakage of the outer film 50 can be suppressed. Furthermore, from the viewpoint of increasing the tensile elongation of the outer film 50, the stretched polyester resin layer is preferably a biaxially oriented polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially oriented polyamide resin layer. Moreover, from the viewpoint of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially oriented polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially oriented nylon (ONy) film. Note that the base layer 51 may be composed of both a stretched polyester resin layer and a stretched polyamide resin layer. 。

[0023] The barrier layer 52 is a layer that at least prevents the penetration of moisture. The barrier layer 52 is joined to the substrate layer 51, for example, via an adhesive layer 54. Examples of barrier layers 52 include metal foil, vapor-deposited film, and resin layer. Examples of vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Examples of resin layers include fluorine-containing resins such as polymers mainly composed of polyvinylidene chloride, chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, as well as ethylene vinyl alcohol copolymers. In addition, a resin film having at least one of these vapor-deposited films and resin layers can also be provided as the barrier layer 52. Multiple layers of the barrier layer 52 may be provided. Preferably, the barrier layer 52 includes a layer made of a metal material. Examples of metal materials constituting the barrier layer 52 include aluminum alloys, stainless steel, titanium steel, and steel sheets. When used as a metal foil, it is preferable to include at least one of aluminum alloy foil and stainless steel foil.

[0024] In the barrier layer 52, the layer composed of the aforementioned metal material may include recycled metal material. Examples of recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, or steel sheet. These recycled materials can each be obtained by known methods. Recycled aluminum alloy can be obtained, for example, by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 52 may be composed solely of recycled material, or it may be composed of a mixture of recycled material and virgin material. Recycled metal material refers to metal material that has been recovered, isolated, and purified from various products used in the market or waste generated from manufacturing processes to make it reusable. Virgin metal material refers to new metal material refined from natural metal resources (raw materials) and is not recycled material.

[0025] From the viewpoint of improving the formability or conformability of the outer film 50, the aluminum alloy foil is more preferably a soft aluminum alloy foil composed of, for example, an annealed aluminum alloy, and from the viewpoint of further improving formability or conformability, it is more preferably an aluminum alloy foil containing iron. In an iron-containing aluminum alloy foil (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, and more preferably 0.5 to 2.0% by mass. By having an iron content of 0.1% by mass or more, an outer film 50 with better formability can be obtained. By having an iron content of 9.0% by mass or less, an outer film 50 with better flexibility can be obtained. Silicon, magnesium, copper, manganese, etc. may also be added as needed. Softening can be achieved by annealing treatment, etc. From the viewpoint of improving the mechanical strength of the outer film 50, the aluminum alloy foil is more preferably a hard aluminum alloy foil composed of, for example, a work-hardened aluminum alloy. Examples of hard aluminum alloy foils include aluminum alloy foils having compositions specified in JIS H4160:1994 A8021H-H18, JIS H4160:1994 A8079H-H18, JIS H4000:2014 A8021P-H14, or JIS H4000:2014 A8079P-H14. From the viewpoint of improving the mechanical strength of the outer film 50, it is preferable that the aluminum alloy foil is an aluminum alloy foil containing magnesium. In an aluminum alloy foil containing magnesium (100% by mass), the magnesium content is preferably 0.2 to 5.6% by mass, and more preferably 0.2 to 3.0% by mass. Examples of aluminum alloy foils containing magnesium include those having compositions specified in JIS H4000:2017 A5005P-O, JIS H4000:2017 A5050P-O, and JIS H4000:2017 A5052P-O.

[0026] Furthermore, examples of stainless steel foils include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation-hardening stainless steel foils. Moreover, from the viewpoint of providing an outer film 50 with excellent formability, it is preferable that the stainless steel foil be made of austenitic stainless steel.

[0027] Specific examples of austenitic stainless steels that make up stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred among these.

[0028] In the case of metal foil, the thickness of the barrier layer 52 should at least function as a barrier layer that prevents moisture from penetrating, for example, about 5 to 1000 μm. The thickness of the barrier layer 52 is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and particularly preferably about 35 μm or less. Also, the thickness of the barrier layer 52 is preferably about 9.0 μm or more, even more preferably about 20 μm or more, and more preferably about 25 μm or more. Furthermore, preferred ranges for the thickness of the barrier layer 52 include approximately 9.0 to 1000 μm, 9.0 to 1000 μm, 9.0 to 1000 μm, 9.0 to 85 μm, 9.0 to 50 μm, 9.0 to 40 μm, 9.0 to 35 μm, 20 to 85 μm, 20 to 50 μm, 20 to 40 μm, 20 to 35 μm, 25 to 85 μm, 25 to 50 μm, 25 to 40 μm, and 25 to 35 μm. When the barrier layer 52 is made of aluminum alloy foil, the above ranges are particularly preferred. Furthermore, from the viewpoint of providing the outer film 50 with high moldability and high rigidity, the thickness of the barrier layer 52 is preferably about 35 μm or more, more preferably about 45 μm or more, even more preferably about 50 μm or more, even more preferably about 55 μm or more, and also preferably about 200 μm or less, more preferably about 85 μm or less, even more preferably about 75 μm or less, even more preferably about 70 μm or less, and preferably The suitable ranges are approximately 35-200 μm, 35-85 μm, 35-75 μm, 35-70 μm, 45-200 μm, 45-85 μm, 45-75 μm, 45-70 μm, 50-200 μm, 50-85 μm, 50-75 μm, 50-70 μm, 55-200 μm, 55-85 μm, 55-75 μm, and 55-70 μm. The high moldability of the outer film 50 facilitates deep drawing, which can contribute to increasing the capacity of the energy storage device. Furthermore, while increasing the capacity of the energy storage device increases its weight, the increased rigidity of the outer film 50 contributes to the high sealing performance of the energy storage device.Furthermore, in particular when the barrier layer 52 is composed of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and especially preferably about 25 μm or less. Also, the thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Furthermore, preferred ranges for the thickness of the stainless steel foil include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0029] Furthermore, if the barrier layer 52 is aluminum foil, it is preferable to provide a corrosion-resistant coating on at least the side opposite to the base layer 51 to prevent dissolution and corrosion. The barrier layer 52 may have a corrosion-resistant coating on both sides. Here, a corrosion-resistant coating refers to a thin film that provides corrosion resistance (e.g., acid resistance, alkali resistance, etc.) to the barrier layer 52 by performing corrosion prevention treatments on the surface of the barrier layer 52, such as hot water modification treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment with nickel or chromium, or coating agent application. Specifically, a corrosion-resistant coating means a coating that improves the acid resistance of the barrier layer 52 (acid-resistant coating), a coating that improves the alkali resistance of the barrier layer 52 (alkali-resistant coating), etc. One type of treatment may be performed to form the corrosion-resistant coating, or two or more types may be combined. In addition, it is possible to have multiple layers instead of just one layer. Furthermore, among these treatments, hydrothermal modification and anodic oxidation are processes that dissolve the surface of the metal foil with a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may also be included in the definition of chemical conversion treatment. Additionally, if the barrier layer 52 has a corrosion-resistant coating, the barrier layer 52 includes the corrosion-resistant coating.

[0030] The corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 during the molding of the outer film 50, prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride generated by the reaction of electrolyte and water, and in particular prevents the dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52 when the barrier layer 52 is aluminum alloy foil, and improves the adhesion (wettability) of the surface of the barrier layer 52, thereby preventing delamination between the base layer 51 and the barrier layer 52 during heat sealing and during molding.

[0031] The heat-sealable resin layer 53 is joined to the barrier layer 52, for example, via an adhesive layer 55. The heat-sealable resin layer 53 included in the outer film 50 is a layer that imparts heat-seal sealing properties to the outer film 50. Examples of the heat-sealable resin layer 53 include polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polyolefin resins such as polyethylene resin and polypropylene resin, or resin films made of acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. 。

[0032] The outer film 50 preferably has one or more layers having a buffering function (hereinafter referred to as "buffering layers") outside the heat-sealable resin layer 53, and more preferably outside the barrier layer 52. The buffering layers may be laminated on the outside of the base layer 51, or the base layer 51 may also have the function of a buffering layer. If the outer film 50 has multiple buffering layers, the multiple buffering layers may be adjacent to each other, or they may be laminated via the base layer 51 or the barrier layer 52, etc.

[0033] The materials constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. Examples of cushioning materials include rubber, nonwoven fabric, or foamed sheet. Examples of rubber include natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably around 20 to 90. The materials constituting the nonwoven fabric are preferably materials with excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the buffer layer thickness is preferably 100 μm, more preferably 200 μm, and still more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the buffer layer thickness is preferably 5000 μm, and still more preferably 3000 μm. The preferred thickness ranges for the buffer layer are 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm. Among these, the most preferred thickness range for the buffer layer is 1000 μm to 3000 μm.

[0034] When the buffer layer is made of rubber, the lower limit of the buffer layer thickness is preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit of the buffer layer thickness is preferably 10 mm, more preferably 5 mm, and still more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the buffer layer thickness is 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0035] If the outer film 50 has a buffer layer, the buffer layer functions as a cushion, thus preventing damage to the outer film 50 from impact when the energy storage device 10 is dropped or from handling during the manufacturing of the energy storage device 10.

[0036] The lid 60 comprises a covering 70 and a lid body 80.

[0037] The coating 70 has a first main body portion 70A and a first projection portion 70B. The first main body portion 70A has a shape similar to, for example, a hollow rectangular parallelepiped. A space 79 is formed inside the first main body portion 70A. The material constituting the coating 70 can be arbitrarily selected. From the viewpoint of suitably forming the second sealing portion 92, which will be described later, it is preferable that the coating 70 is composed of a metallic material. Here, "composed of a metallic material" means that when the total material constituting the coating 70 is considered to be 100% by mass, the metallic material content is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. That is, the material constituting the coating 70 can contain materials other than metallic materials in addition to metallic materials. The metallic material constituting the coating 70 can be arbitrarily selected. The metallic material constituting the coating 70 is, for example, aluminum, aluminum alloy, nickel, copper, or copper alloy. For example, if the electrode body 20 is a lithium-ion battery, the coating 70 connected to the positive electrode is preferably made of aluminum or an aluminum alloy. The coating 70 connected to the negative electrode is preferably made of nickel, copper, or a copper alloy. The material constituting the coating 70 connected to the negative electrode may be copper with nickel plating. The material constituting the coating 70 may also include recycled metal materials. In this embodiment, the coating 70 is made only of metal material. Since the coating 70 is made of metal material, it also functions as an electrode terminal. This simplifies the configuration of the energy storage device 10. When the coating 70 is made of metal material, it is preferable that the coating 70 has a corrosion-resistant coating as described in the barrier layer 52.

[0038] In another example, the coating 70 may be composed of a resin material. Here, "composed of a resin material" means that when the total mass of the materials constituting the coating 70 is considered to be 100% by mass, the resin material content is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In other words, the materials constituting the coating 70 may contain materials other than resin materials in addition to resin materials. From the viewpoint of suitably forming the second sealing portion 92, which will be described later, it is preferable that the resin material is a material that has expansion and contraction properties similar to those of the metal material contained in the materials constituting the lid body 80.

[0039] Specific examples of resins include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, and phenolic resin, as well as modified versions of these resins. The resin material may also be a mixture of these resins, a copolymer, or a modified version of a copolymer. Among these, the resin material is preferably a heat-fusible resin such as polyester or polyolefin, and more preferably polyolefin. When the resin material is a resin, the joint 80B may be formed by any molding method.

[0040] The resin material included in the material constituting the coating 70 is preferably an olefin-based random copolymer, more preferably contains a resin containing a polyolefin skeleton as its main component, more preferably contains polyolefin as its main component, and more preferably contains polypropylene as its main component. The polyolefin may be an acid-modified polyolefin. The resin material included in the material constituting the coating 70 preferably contains multiple types of amide lubricants. Furthermore, the resin material included in the material constituting the coating 70 preferably contains, in addition to saturated fatty acid amides, multiple types of amide lubricants, including unsaturated fatty acid amides. The resin material included in the material constituting the coating 70 may be a polyolefin resin to which a propylene-based elastomer with a melting point higher than 150°C has been added.

[0041] Examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyesters. Examples of copolymerized polyesters include copolymerized polyesters with ethylene terephthalate as the main repeating unit. Specifically, examples include copolymerized polyesters polymerized with ethylene isophthalate using ethylene terephthalate as the main repeating unit (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl dicarboxylate), and polyethylene (terephthalate / decanedicarboxylate). Among these, polybutylene terephthalate is preferred as the resin material from the viewpoint of improving heat resistance and pressure resistance.

[0042] Furthermore, specific examples of polyolefins include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylene such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymer of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymer of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. When polyolefin resins are copolymers, they may be block copolymers or random copolymers. Among these, polypropylene is preferred as the resin material because it has excellent heat-sealability and electrolyte resistance.

[0043] The resin material may contain fillers as needed. Specific examples of fillers include glass beads, graphite, glass fibers, and carbon fibers. By including the above-mentioned fillers in the resin material, the deformation resistance of the joint 80B to temperature changes can be improved.

[0044] The melt mass flow rate of the resin material contained in the material constituting the coating 70 is preferably in the range of 1 g / 10 min to 100 g / 10 min, and more preferably in the range of 5 g / 10 min to 80 g / 10 min. The melt mass flow rate is measured according to JIS K7210-1:2014. The measurement temperature for the melt mass flow rate is 230°C.

[0045] The first main body portion 70A has a first surface 70X and a second surface 70Y. The first surface 70X faces the electrode body 20. An opening 70Z is formed on the first surface 70X, almost entirely. The second surface 70Y is the surface opposite to the first surface 70X. An opening 70YA is formed on the second surface 70Y, into which the lid body 80, described later, is fitted. The opening 70YA penetrates the second surface 70Y. The shape of the opening 70YA in a front view can be arbitrarily selected according to the shape of the lid body 80. The shape of the opening 70YA may be a square, a rectangle, a polygon with more than one triangle, a circle, or an ellipse. In this embodiment, the shape of the opening 70YA in a front view is a rectangle. It is preferable that the corners of the opening 70YA are rounded by R processing. When the first main body portion 70A is made up of a resin material, from the viewpoint of suitably joining the lid body 80, it is preferable that at least a portion of the inner circumferential surface of the opening 70YA is bonded to an adhesive film that can be bonded to a metal material and a resin material. In another example, when the first main body portion 70A is made up of a resin material, from the viewpoint of suitably joining the lid body 80, it is preferable that at least a portion of the first main body portion 70A corresponding to the inner circumferential surface of the opening 70YA has a layer that can be bonded to a metal material.

[0046] The first main body portion 70A includes an upper portion 71, side portions 72 and 73, a lower portion 74, and a protruding portion 70T. The upper portion 71 constitutes the upper surface of the lid 60. In a front view of the lid 60, the upper portion 71 extends in a first direction (in this embodiment, the LR direction). The side portions 72 and 73 connect to the upper portion 71 and constitute the side surface of the lid 60. In a front view of the lid 60, the side portions 72 and 73 extend in a second direction (in this embodiment, the UD direction) that intersects the first direction. In this embodiment, in a front view of the lid 60, the first direction and the second direction are orthogonal. The first direction and the second direction do not have to be orthogonal in a front view of the lid 60. The lower portion 74 constitutes the lower surface of the lid 60. In a front view of the lid 60, the lower portion 74 extends in a first direction (in this embodiment, the LR direction).

[0047] The protruding portion 70T protrudes inward from the upper portion 71, the side portions 72, 73, and the lower portion 74 of the first main body portion 70A. The protruding portion 70T defines the portion that covers the lid body 80, in other words, the opening 70YA. The amount of protrusion of the protruding portion 70T from the upper portion 71, the side portions 72, 73, and the lower portion 74 can be arbitrarily selected. The larger the amount of protrusion of the protruding portion 70T from the upper portion 71, the side portions 72, 73, and the lower portion 74, the smaller the opening area of ​​the opening 70YA. In other words, the smaller the amount of protrusion of the protruding portion 70T from the upper portion 71, the side portions 72, 73, and the lower portion 74, the larger the opening area of ​​the opening 70YA. In the first main body portion 70A, the protruding portion 70T may be omitted.

[0048] The first main body portion 70A further includes boundaries 75, 76, 77, and 78. Boundary 75 is the boundary between the upper portion 71 and the side portion 72. Boundary 76 is the boundary between the upper portion 71 and the side portion 73. Boundary 77 is the boundary between the lower portion 74 and the side portion 72. Boundary 78 is the boundary between the lower portion 74 and the side portion 73. The shape of boundaries 75 to 78 may be angular, or they may be rounded by R-processing. In this embodiment, boundaries 75 to 78 are angular.

[0049] The first projection 70B protrudes outward from the outer casing 40 from the edge of the opening 70YA on the second surface 70Y of the first main body 70A. The first projection 70B only needs to be formed on at least a portion of the edge of the opening 70YA. In this embodiment, the first projection 70B is formed over the entire edge of the opening 70YA. The first projection 70B may also protrude from at least a portion of the edge of the second surface 70Y.

[0050] The material constituting the lid body 80 shown in Figure 5 can be arbitrarily selected. From the viewpoint of suitably forming the second sealing portion 92 described later, it is preferable that the lid body 80 be made up of a metal material. The definition of "made up of a metal material" and the specifications of the metal material constituting the lid body 80 are the same as those for the cover 70. The lid body 80 may also be made up of a resin material. The definition of "made up of a resin material" and the specifications of the resin material constituting the lid body 80 are the same as those for the cover 70. The lid body 80 has a first surface 81, a second surface 82, and a covering portion 83. The first surface 81 faces the electrode body 20. The first surface 81 is joined to the end of the current collector (not shown) of the electrode body 20, for example, by welding. The second surface 82 is the surface opposite to the first surface 81. Electrode terminals may be connected to the second surface 82. The portion of the second surface 82 indicated by the double line in a frame-like manner has a groove-shaped recess formed therein, which is the recess 82A that constitutes the second sealing portion 92 described later. If the lid body 80 is made up of a metal material, it is preferable that the lid body 80 has a corrosion-resistant coating as described in the barrier layer 52.

[0051] The covering portion 83 is connected to the first surface 81 and the second surface 82, and at least a portion of it is covered by the first main body portion 70A. In this embodiment, the entire covering portion 83 is covered by the inner circumferential surface of the opening 70YA when the lid body 80 is fitted into the opening 70YA of the covering body 70. When the lid body 80 is fitted into the opening 70YA of the covering body 70, a portion of the covering portion 83 may be exposed from the covering body 70. The lid body 80 may also be fitted into the opening 70Z.

[0052] The covering portion 83 includes a first covering portion 83A, a second covering portion 83B, a third covering portion 83C, and a fourth covering portion 83D. The first covering portion 83A constitutes the upper surface of the lid body 80. In a front view of the lid body 80, the first covering portion 83A extends in a first direction (in this embodiment, the LR direction). The second covering portion 83B and the third covering portion 83C are connected to the first covering portion 83A and constitute the side surface of the lid body 80. In a front view of the lid body 80, the second covering portion 83B and the third covering portion 83C extend in a second direction (in this embodiment, the UD direction) that intersects the first direction. In this embodiment, in a front view of the lid body 80, the first direction and the second direction are orthogonal. The first direction and the second direction do not have to be orthogonal in a front view of the lid body 80. The fourth covering portion 83D constitutes the lower surface of the lid body 80. The fourth covering portion 83D extends in the first direction (in this embodiment, the LR direction) when viewed from the front of the lid body 80.

[0053] The covering portion 83 further includes boundaries 84, 85, 86, and 87. Boundary 84 is the boundary between the first covering portion 83A and the second covering portion 83B. Boundary 85 is the boundary between the first covering portion 83A and the third covering portion 83C. Boundary 86 is the boundary between the fourth covering portion 83D and the second covering portion 83B. Boundary 87 is the boundary between the fourth covering portion 83D and the third covering portion 83C. The shape of boundaries 84 to 88 may be angular, or it may be rounded by R processing. In this embodiment, boundaries 84 to 87 are angular.

[0054] If the lid 60 is plate-shaped as a whole, it is preferable that the lid 60 has a certain thickness so that deformation of the outer casing 40 is suppressed even when the energy storage devices 10 are stacked on top of each other. The minimum thickness of the first main body portion 70A in the FB direction is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum thickness of the first main body portion 70A of the lid 60 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum thickness of the first main body portion 70A of the lid 60 may be 20 mm or more. The preferred range for the thickness of the first main body portion 70A of the lid 60 is 1.0 mm to 20 mm, 1.0 mm to 15 mm, 1.0 mm to 10 mm, 3.0 mm to 20 mm, 3.0 mm to 15 mm, 3.0 mm to 10 mm, 4.0 mm to 20 mm, 4.0 mm to 15 mm, and 4.0 mm to 10 mm. The thickness of the first main body portion 70A of the lid 60 may vary depending on the part of the lid 60. If the thickness of the first main body portion 70A of the lid 60 varies depending on the part, the thickness of the first main body portion 70A of the lid 60 shall be the thickness of the thickest part.

[0055] In this embodiment, the first sealing portion 91 is formed by heat sealing the opposing surfaces (heat-fusible resin layers 53) of the outer film 50.

[0056] The first sealing portion 91 is composed of a portion where the first edge 50A and the second edge 50B of the outer film 50 shown in Figure 3 overlap. The first sealing portion 91 extends in the longitudinal direction (FB direction) of the outer body 40. The position in the outer body 40 where the first sealing portion 91 is formed can be arbitrarily selected. In this embodiment, it is preferable that the base 91X of the first sealing portion 91 is located on the edge 43 of the boundary between the first surface 41A and the second surface 42A of the outer body 40. The base 91X of the first sealing portion 91 may be located on any surface of the outer body 40. From the viewpoint of making the energy storage device 10 compact, it is preferable that the first sealing portion 91 is folded, for example, on the first surface 41A or the second surface 42A of the outer body 40 when the energy storage device 10 is in use.

[0057] In this embodiment, the portion of the outer film 50 including the end in the FB direction is sandwiched between the inner circumferential surface of the opening 70YA of the first main body portion 70A and the covering portion 83, thereby forming the second sealing portion 92 (see Figures 6 and 7). In this embodiment, the second sealing portion 92 has a crimped portion 92X in which the first protrusion 70B of the covering body 70 is crimped to a recess 82A of the lid body 80. The crimped portion 92X is a portion in which the covering body 70 and the lid body 80 are mechanically joined by utilizing the plastic deformation of the covering body 70 and the lid body 80. Preferably, the crimped portion 92X is formed by the plastic deformation of the covering body 70 and the lid body 80 without using other members such as rivets. In this embodiment, the first protrusion 70B is formed over the entire edge of the opening 70YA. Therefore, the crimped portion 92X is formed over the entire opening 70YA. The outer film 50 does not necessarily have to be placed on the first protruding portion 70B. The crimped portion 92X may be formed including the portion in which the outer film 50 is sandwiched between the first main body portion 70A and the lid body 80, or the crimped portion 92X may be formed only in the portion in which the outer film 50 is sandwiched between the first main body portion 70A and the lid body 80.

[0058] <1-2. Method for manufacturing energy storage devices> Figure 8 is a flowchart showing an example of a method for manufacturing the energy storage device 10. The method for manufacturing the energy storage device 10 includes, for example, a first step, a second step, a third step, a fourth step, a fifth step, and a sixth step. Steps 1 to 6 are carried out, for example, by a manufacturing apparatus for the energy storage device 10. At least a portion of steps 1 to 6 may be carried out by an operator. Note that steps 1 to 6 are names for each step in the method for manufacturing the energy storage device 10, and do not necessarily indicate the order of the steps. The order of the following steps can be changed as desired.

[0059] In the first step of step S1, the manufacturing apparatus places a pair of lid bodies 80 to the side of the electrode body 20 and electrically connects the electrode body 20 and the lid bodies 80.

[0060] The second step, S2, is performed after the first step. In the second step, the manufacturing apparatus wraps the electrode body 20 and the pair of lid bodies 80 with an outer film 50.

[0061] The second step of step S3 is performed after the second step. In the third step, the end seal portion is formed. The end seal portion is a portion of the outer film 50 in which the first sealing portion 91 is to be formed, in which a predetermined range including both ends in the LR direction is joined. The end seal portion is folded toward the first surface 41A or the second surface 42A.

[0062] Step S4, the fourth step, is performed after the third step. In the fourth step, the manufacturing apparatus fits the lid body 80 into the opening 70YA of the covering 70. Upon completion of the fourth step, the portion of the outer film 50 including the FB direction end, and the end seal portion, are sandwiched between the inner circumferential surface of the opening 70YA of the covering 70 and the covering portion 83 of the lid body 80.

[0063] Step S5, the fifth step, is performed after the fourth step. In the fifth step, the manufacturing apparatus forms the second sealing portion 92 by crimping the lid body 80 and the first protrusion 70B of the covering 70.

[0064] Step S6, the sixth step, is performed before or after step 5. In step 6, the manufacturing apparatus forms the first sealing portion 91 by heat sealing the heat-sealable resin layer 53 of the portion of the outer film 50 including the first edge 50A and the heat-sealable resin layer 53 of the portion including the second edge 50B.

[0065] <1-3. Function and Effects of Energy Storage Devices> The energy storage device 10 has a second sealing portion 92 in which the outer film 50 is sandwiched between the covering 70 and the lid body 80, so that the outer film 50 is less likely to come off the lid body 60. For this reason, the energy storage device 10 has high airtightness.

[0066] [2. Variant] The embodiments described above are illustrative of possible forms of the energy storage device, cover, and method for manufacturing the energy storage device according to the present invention, and are not intended to limit their forms. The energy storage device, cover, and method for manufacturing the energy storage device according to the present invention may take forms different from those illustrated in the embodiments. One example is a form in which a part of the configuration of the embodiment is replaced, modified, or omitted, or a form in which a new configuration is added to the embodiment. Several examples of modifications of the embodiments are shown below. Note that the following modifications can be combined with each other as long as they do not contradict each other technically.

[0067] <2-1. First variation> In the above embodiment, the configuration of the lid body 80 is changeable. Figure 9 is a perspective view of the lid body 180 of the first modified energy storage device 10. The lid body 180 comprises a second body portion 180A and a second protrusion portion 180B.

[0068] The configuration of the second main body 180A is the same as that of the lid body 80. The second projection 180B protrudes from the portion of the second main body 180A that includes the edge of the second surface 82. The second projection 180B only needs to be formed on at least a part of the portion that includes the edge of the second surface 82. In this embodiment, the second projection 180B is formed over the entire portion that includes the edge of the second surface 82. The second projection 180B may also protrude from any portion other than the portion that includes the edge of the second surface 82.

[0069] Figure 10 is a cross-sectional view of the first modified energy storage device 10. The first modified energy storage device 10 includes a second sealing portion 192. In the second sealing portion 192, a portion including the end of the outer film 50 in the FB direction is sandwiched between the first protrusion 70B of the covering body 70 and the second protrusion 180B of the lid body 180. The second sealing portion 192 has a crimped portion 192X. The crimped portion 192X is a portion that is crimped by bending the first protrusion 70B, the second protrusion 180B, and the outer film 50 so as to approach the second surface 82 of the second body portion 180A, and then crushing the bent portion. That is, the crimped portion 192X is formed by bending and crimping.

[0070] <2-2. Second variation> In the above embodiment, the configuration of the second sealing portion 92 is changeable. Figure 11 is a cross-sectional view of the energy storage device 10 of the second modified example. The energy storage device 10 of the second modified example may have an adhesion assisting member 100 disposed between the first protrusion 70B and the lid body 80 in the second sealing portion 92. The adhesion assisting member 100 is a member that enhances the adhesion between the first protrusion 70B and the lid body 80 after the crimping portion 92X is formed in the second sealing portion 92. The adhesion assisting member 100 is, for example, a foam material, sponge, resin, or rubber. The adhesion assisting member 100 may be disposed between the covering body 70 and the outer film 50, or between the outer film 50 and the lid body 80. The adhesion assisting member 100 may be disposed both between the covering body 70 and the outer film 50, and between the outer film 50 and the lid body 80. The adhesive support member 100 may consist of an element positioned between the covering body 70 and the outer film 50, and an element positioned between the outer film 50 and the lid body 80, which may be an integrated or separate component.

[0071] <2-3. Third Variation> As shown in Figure 12, the third modified energy storage device 10, which is a further modified version of the first modified version, may include a contact assist member 200. The specifications of the contact assist member 200 are the same as those of the contact assist member 100. The contact assist member 100 may be placed between the covering body 70 and the outer film 50, or between the outer film 50 and the lid body 180.

[0072] <2-4. Fourth Variation> In the first modified example, the lid 60 may omit the covering 70 or the lid body 180. Figure 13 is a cross-sectional view of the energy storage device 10 of the fourth modified example, which is a further modification of the first modified example. In the example shown in Figure 13, the lid 60 omits the covering 70. The second sealing portion 192 may be formed by crimping the second projection 180B of the lid body 180 with the end of the outer film 50. If the lid body 180 is omitted from the lid 60, the second sealing portion 192 may be formed by crimping the first projection 70B of the covering 70 with the end of the outer film 50.

[0073] <2-5. Fifth variation> In the above embodiment, the method for manufacturing the energy storage device 10 can be arbitrarily changed. For example, the lid body 80 may be fitted into the covering body 70 with the lid body 80 temporarily joined to the outer film 50, or with the lid body 80 not temporarily joined to the outer film 50, and then the second sealing portion 92 may be formed. In another example, the lid body 80 may be fitted into the covering body 70 with the lid body 80 temporarily joined to the outer film 50, or with the covering body 70 not temporarily joined to the outer film 50, and then the second sealing portion 92 may be formed.

[0074] <2-6. Sixth Variation> In the above embodiment, the outer film 50 was arranged over almost the entire first protrusion 70B, but the outer film 50X does not have to be arranged over at least a portion of the first protrusion 70B. Figure 14 is a cross-sectional view of a sixth modified energy storage device. In the example shown in Figure 14, the outer film 50 is not arranged over the first protrusion 70B. In the sixth modified example, the crimped portion 92X may be formed including the portion in which the outer film 50 is sandwiched between the first main body 70A and the lid body 80, or the crimped portion 92X may be formed only in the portion in which the outer film 50 is sandwiched between the first main body 70A and the lid body 80. In the sixth modified example, in order to improve the airtightness of the second sealing portion 92, it is preferable that at least a portion of the second sealing portion 92 is subjected to a joining process after the crimped portion 92X is formed, depending on the materials constituting the covering 70 and the lid body 80. The joining process is, for example, welding. Welding methods include, for example, pulsed heat welding, laser welding, arc welding, electron beam welding, gas welding, pressure welding, or brazing. The joining process may be partially applied to the second sealing portion 92. In the second sealing portion 92, areas where the joining process is not performed have lower joining strength than areas where the joining process is performed. Therefore, in the second sealing portion 92, areas where the joining process is not performed will delaminate before areas where the joining process is performed when the internal pressure of the outer casing 40 increases. This allows for a certain degree of limitation of the areas from which gas is released. In another example, in the second sealing portion 92, the first protrusion 70B and the lid body 80 may be joined mechanically and also by adhesive. From the viewpoint of limiting the areas from which gas is released when the internal pressure of the outer casing 40 increases, the first protrusion 70B and the lid body 80 may be partially joined by adhesive. The sixth modification can also be applied to the first to fourth modifications.

[0075] <2-7. Seventh Variation> In the above embodiment, the outer film 50 may have a portion in the FB direction in which only the barrier layer 52 is exposed. Figure 15 is a cross-sectional view showing an example of the layer configuration of the outer film 50 provided in the seventh modified energy storage device 10. In the example shown in Figure 15, the barrier layer 52 has a protrusion 52X that protrudes from the base layer 51 and the heat-fusible resin layer 53 in the FB direction. The protrusion 52X may be formed only on one side of the lid 60 in the FB direction, or only on the other side of the lid 60. The second sealing portion 92 is preferably configured to include the protrusion 52X. When the outer film 50 has a protrusion 52X and the barrier layer 52 includes a layer made of a metal material, in order to improve the sealing performance of the second sealing portion 92, it is preferable that the second sealing portion 92 is subjected to a joining process after the crimped portion 92X is formed, depending on the materials constituting the covering 70 and the lid body 80. The joining process is welding. Welding methods include, for example, pulsed heat welding, laser welding, arc welding, electron beam welding, gas welding, pressure welding, or brazing. In another example, the first projection 70B, the projection 52X, and the lid body 80 may be joined by an adhesive or the like in addition to mechanical joining.

[0076] In the seventh modified example, when the protrusions 52X are formed on one side of the lid 60 and the other side of the lid 60 in the FB direction, the lid 60 has a structure that suppresses electrical conductivity between the portion of the lid 60 connected to the electrode and the portion of the lid 60 connected to the electrode.

[0077] Figure 16 is a perspective view of the lid body 80X of the seventh modified example of the energy storage device 10. The lid body 80X has a through hole 80Y formed therein. The through hole 80Y penetrates the first surface 81 and the second surface 82 of the lid body 80X. The shape of the through hole 80Y in a front or rear view of the lid body 80 can be arbitrarily selected. In the example shown in Figure 16, the shape of the through hole 80Y in a front or rear view of the lid body 80X is rectangular. The shape of the through hole 80Y in a front or rear view of the lid body 80 may be a square, circle, ellipse, triangle, or polygon with pentagons or more. A current extraction section 610 and an insulating section 620 are arranged in the through hole 80Y.

[0078] The current extraction section 610 is an element that outputs current and, for example, to which an external device is connected. The current extraction section 610 is made up of a conductive material. The shape of the current extraction section 610 can be arbitrarily selected. In this embodiment, the current extraction section 610 is a rectangular block shape. At least a portion of the current extraction section 610 is housed in the through hole 80Y. In this embodiment, the entire current extraction section 610 is housed in the through hole 80Y. The current extraction section 610 may protrude to the outside of the lid body 80 from at least one of the first surface 81 and the second surface 82 of the lid body 80.

[0079] The insulating portion 620 insulates the lid body 80X from the current extraction portion 610. Therefore, even when the barrier layer 52 and the pair of lids 60 are joined, the current extraction portion 610 of one lid 60 and the current extraction portion 610 of the other lid 60 are not electrically connected. The material constituting the insulating portion 620 can be arbitrarily selected as long as it is a material that can insulate the lid body 80X from the current extraction portion 610. Examples of materials constituting the insulating portion 620 include elastomers, resin materials, or ceramics. Examples of ceramics include glass, oxides, nitrides, carbonates, or hydroxides. The insulating portion 620 is positioned to fill the gap between the current extraction portion 610 and the inner surface of the through hole 80Y. In the seventh modified example, the first sealing portion 91 may be formed by joining the protruding portions 52X of opposing surfaces of the outer film 50. The seventh modification can also be applied to the first to fourth modifications.

[0080] <2-8. Eighth variation> In the above embodiment, the configuration of the outer film 50 is changeable. Figure 17 is a cross-sectional view showing an example of the layer configuration of the outer film 50X provided in the eighth modified energy storage device 10.

[0081] The outer film 50X is a laminate film comprising a first barrier layer 710, a second barrier layer 720, and an insulating layer 730. The first barrier layer 710, the second barrier layer 720, and the insulating layer 730 are laminated in such a way that the first barrier layer 710 and the second barrier layer 720 are not electrically conductive. In the eighth modified example, the first barrier layer 710, the insulating layer 730, and the second barrier layer 720 are laminated in that order from the outside of the outer body 40 toward the electrode body 20. The first barrier layer 710 and the second barrier layer 720 are composed of a metallic material.

[0082] The first barrier layer 710 is joined to the lid 60 connected to the positive electrode. From the viewpoint of increasing the bonding strength between the first barrier layer 710 and the lid 60 connected to the positive electrode, it is preferable that the metallic material included in the material constituting the first barrier layer 710 is the same metallic material included in the material constituting the lid 60 connected to the positive electrode. The second sealing portion 92 is composed of the end portion of the first barrier layer 710.

[0083] The second barrier layer 720 is joined to the lid 60 connected to the negative electrode. From the viewpoint of increasing the bonding strength between the second barrier layer 720 and the lid 60 connected to the negative electrode, it is preferable that the metal material included in the material constituting the second barrier layer 720 is the same metal material included in the material constituting the lid 60 connected to the negative electrode. The second sealing portion 92 is composed of the end portion of the second barrier layer 720.

[0084] The insulating layer 730 insulates the first barrier layer 710 and the second barrier layer 720 so that they do not conduct electricity. The material constituting the insulating layer 730 can be arbitrarily selected as long as it is a material that can insulate the first barrier layer 710 and the second barrier layer 720. Examples of materials constituting the insulating layer 730 are resin, elastomer, or ceramic. Examples of ceramics are glass, oxide, nitride, carbonate, or hydroxide. Multiple materials may be combined to constitute the insulating layer 730. From the viewpoint of suitably insulating the first barrier layer 710 and the second barrier layer 720, it is preferable that the material constituting the insulating layer 730 includes an insulating filler.

[0085] The resins are thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, phenolic resin, fluororesin, and modified versions of these resins. From the viewpoint of moisture barrier properties, it is preferable to use thermoplastic resins such as fluororesin and modified versions of fluororesin.

[0086] Ceramics are, for example, oxides or nitrides. Oxides include, for example, magnesium oxide, silicon oxide, aluminum oxide, or tin oxide. These oxides have moisture barrier properties.

[0087] Examples of nitrides include aluminum nitride, boron nitride, or silicon nitride. From the viewpoint of moisture barrier properties, silicon nitride is preferred.

[0088] A carbonate is, for example, magnesium carbonate. A hydroxide is, for example, magnesium hydroxide. Magnesium carbonate and magnesium hydroxide have moisture barrier properties.

[0089] Preferably, the outer film 50 includes an overlapping portion 700X in a plan view, which is the portion where the first barrier layer 710, the insulating layer 730, and the second barrier layer 720 overlap. When the outer film 50 includes the overlapping portion 700X, even if the material constituting the insulating layer 730 does not have moisture barrier properties, the moisture barrier properties are enhanced by the first barrier layer 710 and the second barrier layer 720. In the eighth modified example, the overlapping portion 700X is formed to cover almost the entire upper and lower surfaces of the electrode body 20.

[0090] The first barrier layer 710 extends in the FB direction beyond the second barrier layer 720 and the insulating layer 730 to the side of the lid 60 that is connected to the positive electrode.

[0091] The second barrier layer 720 extends in the FB direction further towards the lid 60 connected to the negative electrode than the first barrier layer 710 and the insulating layer 730. Furthermore, from the viewpoint of suppressing short circuits between the second barrier layer 720 and the electrode body 20, it is preferable that another insulating layer be laminated on the side of the second barrier layer 720 opposite to the side on which the insulating layer 730 is laminated.

[0092] From the viewpoint of effectively suppressing electrical conductivity between the first barrier layer 710 and the second barrier layer 720, it is preferable that, in the FB direction, the end portion 730X of the insulating layer 730 on the lid 60 side that is connected to the positive electrode is located closer to the lid 60 connected to the positive electrode than the end portion 720X of the second barrier layer 720 on the lid 60 side that is connected to the positive electrode.

[0093] From the viewpoint of effectively suppressing electrical conductivity between the first barrier layer 710 and the second barrier layer 720, it is preferable that, in the FB direction, the end portion 730Y on the lid 60 side of the insulating layer 730 that is connected to the negative electrode is located closer to the lid 60Y connected to the negative electrode than the end portion 710Y on the lid 60 side of the first barrier layer 710 that is connected to the negative electrode.

[0094] In the eighth modified example, the first barrier layer 710 and the second barrier layer 720 are insulated by the insulating layer 730, so the cover 60 connected to the positive electrode and the cover 60 connected to the negative electrode are not electrically connected.

[0095] Figure 18 is a cross-sectional view showing an example of the layer configuration of the outer film 50Y of the energy storage device 10 of another modification of the eighth modification. As shown in Figure 18, the outer film 50Y does not have to have an overlapping portion 700X. In the example shown in Figure 18, one of the first barrier layer 710 and the second barrier layer 720 of the outer film 50 is laminated in a location where the other of the insulating layer 730 is not laminated. In the example shown in Figure 17, the insulating layer 730 includes a portion where neither the first barrier layer 710 nor the second barrier layer 720 is laminated.

[0096] Figure 19 is a cross-sectional view showing an example of the layer configuration of the outer film 50Z of an energy storage device 10, which is a further variation of the eighth variation. As shown in Figure 19, the first barrier layer 710 and the second barrier layer 720 may be laminated on the same surface of the insulating layer 730. In the example shown in Figure 19, the first barrier layer 710 and the second barrier layer 720 are laminated on the surface of the insulating layer 730 opposite to the surface facing the electrode body 20. Preferably, the first barrier layer 710 and the second barrier layer 720 are laminated on the insulating layer 730 such that a gap is formed in the FB direction so that they do not conduct electricity with each other. If the material constituting the insulating layer 730 does not have moisture barrier properties, any layer containing a material with moisture barrier properties may be laminated between the first barrier layer 710 and the second barrier layer 720 of the insulating layer 730. Note that the first barrier layer 710 and the second barrier layer 720 may be laminated on the surface of the insulating layer 730 facing the electrode body 20. In addition, in the eighth modified example and related modified examples, the first sealing portion 91 may be formed by joining the first barrier layers 710, the second barrier layers 720, or the insulating layers 730 of the outer film 50 that face each other.

[0097] <2-9. Ninth Variation> In the above embodiment, elements of the covering 70 and lid body 80 that include a metal material may have minute irregularities formed on the surface that contacts the resin material portion of the outer film 50, for example, by laser treatment. The portion of the elements of the covering 70 and lid body 80 that include a metal material and the portion of the outer film 50 that includes a resin material, for example, the base layer 51 and the heat-fusible resin layer 53, are more firmly joined by an anchoring effect. This improves the sealing performance of the energy storage device 10. The covering 70, lid body 80, and outer film 50 may be joined by welding. Welding methods include, for example, pulse heat welding, laser welding, arc welding, electron beam welding, gas welding, pressure welding, or brazing. If at least one of the covering 70 and lid body 80 includes a resin material, minute irregularities may be formed on at least a portion of the surface that contacts the resin material portion of the protrusion 52X in the seventh modification by laser treatment. The ninth modification can also be applied to the eighth modification.

[0098] <2-10. 10th Variation> In the above embodiment, the outer film 50 of the energy storage device 10 may extend outward in the FB direction beyond at least one of the two lids 60. The electrode body 20 is sealed when the portion of the outer film 50 that extends outward beyond the lids 60 is closed. The portion of the outer film 50 that extends outward beyond the lids 60 may be folded inward so that the outer surfaces of the outer film 50 come into contact with each other, as in a Goebeltop type container, or it may be folded toward any surface of the outer body 40, as in a brick type container.

[0099] <2-11. 11th Variation> In the above embodiment, the outer casing 40 may not have one of the two lids 60. In this modification, in the FB direction, in the portion of the outer casing 40 where the lid 60 is omitted, the electrode body 20 is sealed by closing the portion of the outer film 50 that extends outward from the electrode body 20. The portion of the outer film 50 that extends outward from the electrode body 20 may be folded to form a Goebeltop type container or a brick type container, similar to the tenth modification.

[0100] <2-12. Twelfth variation> In the above embodiment, the outer shape of the exterior body 40 can be arbitrarily changed. The outer shape of the exterior body 40 may be a cylinder, a rectangular prism, or a cube.

[0101] <2-13. 13th Variation> In the above embodiment, the electrode body 20 was wrapped in one outer film 50, but it may be wrapped in two or more outer films 50. [Explanation of Symbols]

[0102] 10: Energy storage devices 20: Electrode body 40: Exterior 50: Exterior film 60: Lid 70, 470: Covering body 70A: First main body 70B: 1st protrusion 80, 180: Lid body 92, 192: Second sealing section (sealing section) 92X, 192X: Crimping part 180A: Second main unit 180B: Second protrusion 100, 200: Adhesion support part

Claims

1. Electrode body and The electrode body is enclosed by an outer casing, The exterior body is, The outer film enclosing the electrode body, It has a lid that seals the electrode body together with the outer film, The aforementioned cover is A coating comprising at least one of a resin material and a metal material (excluding films as a form of coating), It has a lid body which is joined to the covering, The exterior body has a sealing portion in which the exterior film is sandwiched between the covering body and the lid body. The sealing portion has a crimped portion in which the covering and the lid body are crimped together. Energy storage device.

2. Electrode body and The electrode body is enclosed by an outer casing, The exterior body is, The outer film enclosing the electrode body, It has a lid that seals the electrode body together with the outer film, The aforementioned cover is Covering and It has a lid body which is joined to the covering, The exterior body has a sealing portion in which the exterior film is sandwiched between the covering body and the lid body. The sealing portion has a crimped portion in which the covering and the lid body are crimped together. Energy storage device.

3. The covering body has a first main body portion and a first protruding portion that protrudes from the first main body portion. The lid body has a second body portion and a second protruding portion that protrudes from the second body portion. The sealing portion is formed by folding the outer film while it is sandwiched between the first and second protrusions. The energy storage device according to claim 1 or 2.

4. The covering has an adhesive assist member that is positioned between the covering and the lid body. The energy storage device according to claim 1 or 2.

5. A lid used as an outer casing for an energy storage device, A coating comprising at least one of a resin material and a metal material (excluding films as a form of coating), It comprises a lid body made of a metal material and joined to the covering, The outer film constituting the outer casing is sandwiched between the covering body and the lid body, The covering body and the lid body have a gap for sandwiching the outer film. The covering and the lid body are configured to form a crimped portion. Cover.

6. A method for manufacturing an energy storage device, The aforementioned energy storage device is Electrode body and The electrode body is enclosed by an outer casing, The exterior body is, The outer film enclosing the electrode body, It has a lid that seals the electrode body together with the outer film, The aforementioned cover is A coating comprising at least one of a resin material and a metal material (excluding films as a form of coating), It has a lid body which is joined to the covering, The method for manufacturing the aforementioned energy storage device is as follows: The process includes forming a sealing portion in which the outer film is sandwiched between the covering and the lid body, In the step of forming the sealing portion, the covering and the lid body are crimped together to form a crimped portion. A method for manufacturing energy storage devices.

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