Power storage device, lid member, and method for manufacturing power storage device

Abstract

To provide a power storage device with high sealing performance, a lid member used for the power storage device, and a method for manufacturing the power storage device.SOLUTION: The 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 encloses 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.SELECTED DRAWING: Figure 7

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 technology]

[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 that wraps the electrode assembly and a lid that is joined to the exterior film. [Prior art documents] [Patent documents]

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

[0004] In the above-described 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, and if the exterior film peels off from the lid, the sealing performance of the electricity storage device will be reduced.

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

[0006] An energy storage device according to a first aspect of the present invention comprises an electrode body and an exterior body that seals the electrode body, the exterior body having an exterior film that wraps the electrode body and a lid body that seals the electrode body together with the exterior film, the lid body having a covering body and a lid main body that is joined to the covering body, and the exterior body having a sealing portion in which the exterior film is sandwiched between the covering body and the lid main body.

[0007] An electricity storage device according to a second aspect of the present invention is the electricity storage device according to the first aspect, wherein the sealing portion has a crimping portion where the cover and the lid main body are crimped together.

[0008] An energy storage device according to a third aspect of the present invention is the energy storage device according to the first or second aspect, wherein the covering body has a first main body portion and a first protrusion protruding from the first main body portion, the lid body has a second main body portion and a second protrusion protruding from the second main body portion, and the sealing portion is configured by folding the exterior film while it is sandwiched between the first protrusion and the second protrusion.

[0009] An electricity storage device according to a fourth aspect of the present invention is the electricity storage device according to any one of the first to third aspects, further comprising an adhesion assisting member disposed between the cover and the lid main body.

[0010] An energy storage device according to a fifth aspect of the present invention comprises an electrode body and an exterior body that seals the electrode body, and the exterior body has an exterior film that wraps the electrode body, a lid that seals the electrode body together with the exterior film, and a sealing portion that is sealed by crimping the exterior film and the lid together.

[0011] A lid body according to a sixth aspect of the present invention is a lid body used as an exterior body for an electricity storage device, and comprises a covering body and a lid main body made of a metal material and joined to the covering body, and is configured so that an exterior film constituting the exterior body is sandwiched between the covering body and the lid main body.

[0012] A seventh aspect of the present invention relates to a method for manufacturing an electricity storage device, the method comprising: forming an electrode assembly; and an exterior body sealing the electrode assembly, the exterior body having an exterior film wrapping the electrode assembly and a lid body sealing the electrode assembly together with the exterior film; and the lid body having a covering body and a lid main body joined to the covering body. The method for manufacturing an electricity storage device includes forming a sealing portion in which the exterior film is sandwiched between the covering body and the lid main body. [Effects of the Invention]

[0013] The electricity storage device, the lid, and the method for manufacturing the electricity storage device according to the present invention have high sealing performance. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view of an electricity storage device according to an embodiment. [Figure 2] 2 is a cross-sectional view showing an example of a layer structure of an exterior film included in the electricity storage device of FIG. 1. [Figure 3] FIG. 2 is a diagram showing the exterior film of the power storage device of FIG. 1 in an unfolded state. [Figure 4A] FIG. 2 is a perspective view of a cover provided in the electricity storage device of FIG. 1. [Figure 4B] FIG. 4B is a cross-sectional view taken along line D4B-D4B in FIG. 4A. [Figure 5] FIG. 2 is a perspective view of a lid body included in the electricity storage device of FIG. 1. [Figure 6] FIG. 2 is a front view of the electricity storage device of FIG. 1. [Figure 7] Cross-sectional view taken along line D7-D7 in Figure 1. [Figure 8] 3 is a flowchart showing an example of a method for manufacturing the electricity storage device of FIG. [Figure 9] FIG. 10 is a perspective view of a lid main body included in an electricity accumulation device according to a first modified example. [Figure 10] FIG. 10 is a cross-sectional view of an electricity accumulation device according to a first modified example. [Figure 11] FIG. 10 is a cross-sectional view of an electricity accumulation device according to a second modified example. [Figure 12] FIG. 11 is a cross-sectional view of an electricity accumulation device according to a third modified example. [Figure 13] FIG. 11 is a cross-sectional view of an electricity accumulation device according to a fourth modified example. [Figure 14] FIG. 13 is a cross-sectional view of an electricity accumulation device according to a sixth modified example. [Figure 15] FIG. 13 is a cross-sectional view showing an example of the layer structure of an exterior film included in an electricity storage device according to a seventh modified example. [Figure 16] FIG. 13 is a perspective view of a lid main body included in an electricity accumulation device according to a seventh modified example. [Figure 17] FIG. 13 is a cross-sectional view showing an example of the layer structure of an exterior film included in an electricity storage device according to an eighth modified example. [Figure 18] FIG. 23 is a cross-sectional view showing an example of a layer structure of an exterior film included in an electricity storage device according to another modified example of the eighth modified example. [Figure 19] FIG. 23 is a cross-sectional view showing an example of a layer structure of an exterior film included in an electricity storage device according to yet another modified example of the eighth modified example. DETAILED DESCRIPTION OF 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 this specification, a numerical range indicated by "to" means "greater than or equal to" or "less than or equal to." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less.

[0016] [1. Embodiment] <1-1. Configuration of the power storage device> FIG. 1 is a perspective view schematically showing an electricity storage device 10 of an embodiment. FIG. 2 is a cross-sectional view showing an example of the layer structure of an exterior film 50 included in the electricity storage device 10 of FIG. 1. FIG. 3 is a view of 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 directions indicated by the arrows UD, LR, and FB are common to the subsequent figures.

[0017] The electricity storage device 10 includes an electrode body 20 and an exterior body 40. The electrode body 20 includes electrodes (positive and negative electrodes) constituting an electricity storage member such as a lithium ion battery, a capacitor, an all-solid-state battery, a semi-solid battery, a quasi-solid battery, a polymer battery, an all-resin battery, a lead-acid battery, a nickel-metal hydride battery, a nickel-cadmium battery, a nickel-iron battery, a nickel-zinc battery, a silver oxide-zinc battery, a metal-air battery, a polyvalent cation battery, or a capacitor, as well as a separator. In this embodiment, the electrode body 20 has a substantially rectangular parallelepiped shape. Note that the term "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 portion of its outer surface, for example. The electrode body 20 may have a cylindrical or polygonal prism shape, for example.

[0018] The exterior body 40 seals the electrode assembly 20. The exterior body 40 includes an exterior film 50 and a lid body 60. In the present embodiment, the exterior film 50 is wrapped around the electrode assembly 20. The electrode assembly 20 may be housed inside the exterior film 50 which is configured in a cylindrical shape. The exterior body 40 has a pair of first surfaces 41A, 41B and a pair of second surfaces 42A, 42B. In the present embodiment, the pair of first surfaces 41A, 41B are substantially the same size. In the present embodiment, the pair of second surfaces 42A, 42B are substantially the same size. The pair of first surfaces 41A, 41B have a larger area than the pair of second surfaces 42A, 42B. The pair of lid bodies 60 are respectively arranged on the sides of the electrode assembly 20.

[0019] For example, there is a method of forming a recess in the exterior film 50 through cold forming to accommodate the electrode assembly 20. However, it is not necessarily easy to form a deep recess using this method. Attempting to form a deep recess (e.g., a forming depth of 15 mm) by cold forming increases the likelihood of pinholes or cracks occurring in the exterior film 50, resulting in a decrease in battery performance. On the other hand, the exterior body 40 seals the electrode assembly 20 by wrapping the exterior film 50 around the electrode assembly 20, and therefore can easily seal the electrode assembly 20 regardless of the thickness of the electrode assembly 20. Note that in order to reduce the dead space between the electrode assembly 20 and the exterior film 50 and improve the volumetric energy density of the power storage device 10, it is preferable that the exterior film 50 be wrapped so as to contact the outer surface of the electrode assembly 20. Furthermore, in all-solid-state batteries, it is necessary to apply a high pressure uniformly from the outer surface of the battery to maximize battery performance, so it is necessary to eliminate the space between the electrode assembly 20 and the exterior film 50. Therefore, it is preferable that the exterior film 50 be wrapped so as to contact the outer surface of the electrode assembly 20.

[0020] As shown in FIG. 2 , the exterior film 50 is a laminate (laminate film) having, for example, a base material layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in this order. Note that the exterior film 50 does not need to include all of these layers; for example, it may not include the barrier layer 52. That is, the exterior film 50 may be made of any flexible and easily bendable material, such as a resin film. Note that the exterior film 50 is preferably heat-sealable. The innermost and outermost layers of the exterior film 50 may be heat-sealable resin layers 53. In this case, the exterior film 50 may encase the electrode assembly 20 and the lid 60 by joining the outermost and innermost layers.

[0021] The overall thickness of the exterior film 50 can be selected arbitrarily. From the viewpoint of strength, the thickness of the exterior film 50 is preferably 50 μm or more.

[0022] The substrate layer 51 included in the exterior film 50 is a layer that imparts heat resistance to the exterior film 50 and prevents pinholes from forming during processing or distribution. The substrate layer 51 is composed of, for example, at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer in the substrate layer 51, the barrier layer 52 can be protected during processing of the exterior film 50, and breakage of the exterior film 50 can be prevented. Furthermore, from the viewpoint of increasing the tensile elongation of the exterior film 50, the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer. Furthermore, from the viewpoint of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially stretched polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially stretched nylon (ONy) film. The substrate 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 prevents at least moisture from penetrating. The barrier layer 52 is bonded to the base layer 51 via, for example, an adhesive layer 54. Examples of the barrier layer 52 include metal foils, vapor-deposited films, and resin layers with barrier properties. Vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Resin layers include fluorine-containing resins such as polyvinylidene chloride, polymers based on chlorotrifluoroethylene (CTFE), polymers based on tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers based on fluoroalkyl units, as well as ethylene-vinyl alcohol copolymers. Other examples of the barrier layer 52 include resin films having at least one of these vapor-deposited films and resin layers. The barrier layer 52 may be formed of multiple layers. The barrier layer 52 preferably includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 52 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, it is preferable that the metal material contains at least one of an aluminum alloy foil and a stainless steel foil.

[0024] In the barrier layer 52, the layer made of the aforementioned metallic material may contain recycled metallic material. Examples of recycled metallic material include recycled aluminum alloy, stainless steel, titanium steel, and steel plate. These recycled materials can be obtained by known methods. Recycled aluminum alloy material can be obtained, for example, by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 52 may be made solely of recycled material, or may be made of a mixture of recycled and virgin material. Note that recycled metallic material refers to metallic material that has been made reusable by collecting, isolating, and refining various products used in the market or waste from manufacturing processes. Furthermore, virgin metallic material refers to new metallic material refined from natural metallic resources (raw materials) and is not recycled material.

[0025] From the viewpoint of improving the formability or conformability of the exterior film 50, the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy. From the viewpoint of further improving the formability or conformability, an iron-containing aluminum alloy foil is preferred. In the iron-containing aluminum alloy foil (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. By having an iron content of 0.1% by mass or more, an exterior film 50 with better formability can be obtained. By having an iron content of 9.0% by mass or less, an exterior film 50 with better flexibility can be obtained. Furthermore, silicon, magnesium, copper, manganese, etc. may be added as necessary. Furthermore, softening can be achieved by annealing or the like. From the viewpoint of improving the mechanical strength of the exterior film 50, the aluminum alloy foil is more preferably a hard aluminum alloy foil made of, for example, a work-hardened aluminum alloy. Examples of hard aluminum alloy foils include aluminum alloy foils having a composition defined 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 packaging film 50, the aluminum alloy foil is preferably an aluminum alloy foil containing magnesium. In the 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 aluminum alloy foils having compositions specified in JIS H4000:2017 A5005P-O, JIS H4000:2017 A5050P-O, and JISH4000:2017 A5052P-O.

[0026] Examples of stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. Furthermore, from the viewpoint of providing an exterior film 50 with excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0027] Specific examples of austenitic stainless steels that can be used to form the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.

[0028] In the case of a metal foil, the thickness of the barrier layer 52 should be sufficient to at least function as a barrier layer that prevents moisture penetration, and may be, 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. The thickness of the barrier layer 52 is preferably about 9.0 μm or more, more preferably about 20 μm or more, and more preferably about 25 μm or more. Preferred ranges for the thickness of the barrier layer 52 include about 9.0 to 1000 μm, about 9.0 to 1000 μm, about 9.0 to 1000 μm, about 9.0 to 1000 μm, about 9.0 to 85 μm, about 9.0 to 50 μm, about 9.0 to 40 μm, about 9.0 to 35 μm, about 20 to 85 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 35 μm, about 25 to 85 μm, about 25 to 50 μm, about 25 to 40 μm, and about 25 to 35 μm. When the barrier layer 52 is made of an aluminum alloy foil, the above-mentioned ranges are particularly preferred. From the viewpoint of imparting high formability and high rigidity to the exterior film 50, 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, and even more preferably about 55 μm or more, and is preferably about 200 μm or less, more preferably about 85 μm or less, even more preferably about 75 μm or less, and even more preferably about 70 μm or less. Preferred ranges are approximately 35 to 200 μm, approximately 35 to 85 μm, approximately 35 to 75 μm, approximately 35 to 70 μm, approximately 45 to 200 μm, approximately 45 to 85 μm, approximately 45 to 75 μm, approximately 45 to 70 μm, approximately 50 to 200 μm, approximately 50 to 85 μm, approximately 50 to 75 μm, approximately 50 to 70 μm, approximately 55 to 200 μm, approximately 55 to 85 μm, approximately 55 to 75 μm, and approximately 55 to 70 μm. The high formability of the exterior film 50 facilitates deep drawing, which can contribute to increasing the capacity of the electricity storage device. Furthermore, while increasing the capacity of the electricity storage device increases the weight of the electricity storage device, increasing the rigidity of the exterior film 50 can contribute to high sealing performance of the electricity storage device.In particular, when the barrier layer 52 is made 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 particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. 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, when the barrier layer 52 is an aluminum foil, it is preferable that a corrosion-resistant coating be provided on at least the surface opposite the substrate layer 51 to prevent dissolution and corrosion. The barrier layer 52 may be provided with a corrosion-resistant coating on both sides. Here, the corrosion-resistant coating refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) by performing, for example, a hydrothermal conversion treatment such as boehmite treatment, a chemical conversion treatment, an anodizing treatment, a plating treatment using nickel or chromium, or a corrosion prevention treatment such as applying a coating agent on the surface of the barrier layer 52. Specifically, the corrosion-resistant coating refers to 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), or the like. The corrosion-resistant coating may be formed by one type of treatment or a combination of two or more types. Furthermore, the barrier layer 52 may be formed not only as a single layer but also as a multi-layer. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the surface of the metal foil is dissolved using a treatment agent to form a metal compound with excellent corrosion resistance. Note that these treatments may also be included in the definition of chemical conversion treatment. Furthermore, if the barrier layer 52 has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer 52.

[0030] The corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 during molding of the exterior film 50, prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride produced by a reaction between an electrolyte and water, and particularly prevents dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52 when the barrier layer 52 is an aluminum alloy foil, and also 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 between the base layer 51 and the barrier layer 52 during molding.

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

[0032] The exterior film 50 preferably has one or more layers with a buffer function (hereinafter referred to as "buffer layer") outside the heat-sealable resin layer 53, more preferably outside the barrier layer 52. The buffer layer may be laminated on the outside of the base material layer 51, or the base material layer 51 may also function as a buffer layer. When the exterior film 50 has multiple buffer layers, the multiple buffer layers may be adjacent to each other, or may be laminated with the base material layer 51, the barrier layer 52, or the like interposed therebetween.

[0033] The material constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. Examples of the material having cushioning properties include rubber, nonwoven fabric, and foam sheet. Examples of rubber include natural rubber, fluororubber, and silicone rubber. The rubber hardness is preferably about 20 to 90. The material constituting the nonwoven fabric is preferably a material having excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and even more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the thickness of the buffer layer is preferably 5000 μm, and even more preferably 3000 μm. The thickness of the buffer layer is preferably in the range of 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, and most preferably in the range of 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 even 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] When the exterior film 50 has a buffer layer, the buffer layer functions as a cushion, thereby preventing the exterior film 50 from being damaged by impact when the energy storage device 10 is dropped or by handling during the manufacture of the energy storage device 10.

[0036] The lid body 60 has a cover body 70 and a lid main body 80 .

[0037] The coating 70 has a first main body portion 70A and a first protrusion portion 70B. The first main body portion 70A has a shape similar to a hollow rectangular parallelepiped, for example. A space 79 is formed inside the first main body portion 70A. The material constituting the coating 70 can be selected arbitrarily. From the viewpoint of suitably forming a second sealing portion 92 (described later), the coating 70 preferably contains a metal material. Here, "constituted by containing a metal material" means that, when the entire material constituting the coating 70 is taken as 100% by mass, the content of the metal material 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 material constituting the coating 70 can contain materials other than metal materials in addition to metal materials. The metal material constituting the coating 70 can be selected arbitrarily. The metal material constituting the coating 70 is, for example, aluminum, an aluminum alloy, nickel, copper, or a copper alloy. For example, when 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 plated with nickel. The material constituting the coating 70 may contain recycled metal materials. In this embodiment, the coating 70 is made only of a metal material. Since the coating 70 contains a metal material, it also functions as an electrode terminal. This simplifies the configuration of the electricity storage device 10. When the coating 70 contains a metal material, it is preferable that the coating 70 has the corrosion-resistant coating described for the barrier layer 52.

[0038] In another example, the covering body 70 may be configured to include a resin material. Here, "configured to include a resin material" means that, when the entire material constituting the covering body 70 is taken as 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 material constituting the covering body 70 may contain materials other than the resin material in addition to the resin material. From the viewpoint of suitably forming the second sealing portion 92 described below, the resin material is preferably a material that has the same degree of expansion and contraction as the metal material contained in the material constituting the lid main body 80.

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

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

[0041] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters. Examples of copolymer polyesters include copolymer polyesters whose repeating units are primarily ethylene terephthalate. Specific examples include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl dicarboxylate), and polyethylene (terephthalate / decane dicarboxylate). Among these, polybutylene terephthalate is preferred as the resin material from the viewpoint of improving heat resistance and pressure resistance.

[0042] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. Among these, polypropylene is preferred as the resin material because of its excellent heat-sealing properties and electrolyte resistance.

[0043] The resin as the resin material may contain a filler as needed. Specific examples of the filler include glass beads, graphite, glass fiber, and carbon fiber. By including the filler in the resin as the resin material, the deformation resistance of the bonding portion 80B against 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 in accordance with JIS K7210-1:2014. The melt mass flow rate is measured at 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 assembly 20. An opening 70Z is formed over substantially the entire first surface 70X. The second surface 70Y is the surface opposite the first surface 70X. An opening 70YA into which the lid main body 80 (described later) is fitted is formed in the second surface 70Y. The opening 70YA penetrates the second surface 70Y. The shape of the opening 70YA in a front view can be selected arbitrarily depending on the shape of the lid main body 80. The shape of the opening 70YA may be a square, rectangle, a polygon with more than one side, a circle, or an ellipse. In this embodiment, the shape of the opening 70YA in a front view is rectangular. The corners of the opening 70YA are preferably rounded by performing a rounding process. When the first main body portion 70A is made up of a resin material, it is preferable that an adhesive film bondable to metal materials and resin materials be bonded to at least a portion of the inner circumferential surface of the opening 70YA, from the viewpoint of suitably joining the lid main body 80. In another example, when the first main body portion 70A is made up of a resin material, it is preferable that at least a portion of the portion of the first main body portion 70A corresponding to the inner circumferential surface of the opening 70YA has a layer bondable to metal materials, from the viewpoint of suitably joining the lid main body 80.

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

[0047] The protrusions 70T protrude inward from the upper portion 71, the side portions 72, 73, and the lower portion 74 of the first main body portion 70A. The protrusions 70T define the portions that cover the lid main body 80, in other words, the openings 70YA. The protrusion amounts of the protrusions 70T from the upper portion 71, the side portions 72, 73, and the lower portion 74 can be selected arbitrarily. The greater the protrusion amounts of the protrusions 70T from the upper portion 71, the side portions 72, 73, and the lower portion 74, the smaller the opening area of ​​the openings 70YA. In other words, the smaller the protrusion amounts of the protrusions 70T from the upper portion 71, the side portions 72, 73, and the lower portion 74, the larger the opening area of ​​the openings 70YA. The protrusions 70T may be omitted from the first main body portion 70A.

[0048] The first main body portion 70A further includes boundaries 75, 76, 77, and 78. The boundary 75 is the boundary between the upper portion 71 and the side portion 72. The boundary 76 is the boundary between the upper portion 71 and the side portion 73. The boundary 77 is the boundary between the lower portion 74 and the side portion 72. The boundary 78 is the boundary between the lower portion 74 and the side portion 73. The shapes of the boundaries 75 to 78 may be angular, or may be rounded by applying a rounding process. In this embodiment, the boundaries 75 to 78 are angular.

[0049] The first protrusion 70B protrudes from the edge of the opening 70YA on the second surface 70Y of the first main body 70A toward the outside of the exterior body 40. The first protrusion 70B may be formed on at least a portion of the edge of the opening 70YA. In this embodiment, the first protrusion 70B is formed over the entire edge of the opening 70YA. The first protrusion 70B may protrude from at least a portion of the edge of the second surface 70Y.

[0050] The material constituting the lid body 80 shown in FIG. 5 can be selected arbitrarily. From the viewpoint of suitably forming the second sealing portion 92 described below, the lid body 80 is preferably composed of a metal material. The definition of "composed of a metal material" and the specifications of the metal material constituting the lid body 80 are the same as those of the covering body 70. The lid body 80 may be composed of a resin material. The definition of "composed of a resin material" and the specifications of the resin material constituting the lid body 80 are the same as those of the covering body 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 assembly 20. The first surface 81 is joined to an end of a current collector (not shown) of the electrode assembly 20, for example, by welding. The second surface 82 is the surface opposite the first surface 81. An electrode terminal may be connected to the second surface 82. A groove-like recess is formed in the portion of the second surface 82 framed by double lines, and a recess 82A that constitutes the second sealing portion 92, which will be described later, is formed. When the lid body 80 is made of a metal material, it is preferable that the lid body 80 has the corrosion-resistant coating described for 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 the covering portion 83 is covered by the first main body portion 70A. In this embodiment, the lid main body 80 is fitted into the opening 70YA of the cover 70, so that the entire covering portion 83 is covered by the inner circumferential surface of the opening 70YA. When the lid main body 80 is fitted into the opening 70YA of the cover 70, a portion of the covering portion 83 may be exposed from the cover 70. The lid main body 80 may 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 forms the upper surface of the lid main body 80. The first covering portion 83A extends in a first direction (in this embodiment, the LR direction) when viewed from the front of the lid main body 80. The second covering portion 83B and the third covering portion 83C are connected to the first covering portion 83A and form the side surfaces of the lid main 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 with the first direction when viewed from the front of the lid main body 80. In this embodiment, the first direction and the second direction are orthogonal when viewed from the front of the lid main body 80. The first direction and the second direction do not have to be orthogonal when viewed from the front of the lid main body 80. The fourth covering portion 83D forms the lower surface of the lid main body 80. The fourth covering portion 83D extends in a first direction (LR direction in this embodiment) when the lid main body 80 is seen from the front.

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

[0054] When the lid body 60 is generally plate-shaped, it is preferable that the lid body 60 have a certain thickness so that deformation of the exterior body 40 is suppressed even when the power storage devices 10 are placed one on top of the 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 body 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 body 60 may be 20 mm or more. Preferred ranges for the thickness of the first main body portion 70A of the lid body 60 are 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 body 60 may vary depending on the region of the lid body 60. When the thickness of the first main body portion 70A of the lid body 60 varies depending on the region, the thickness of the first main body portion 70A of the lid body 60 is the thickness of the thickest portion.

[0055] In this embodiment, the first sealed portion 91 is formed by heat-sealing the surfaces (heat-fusible resin layers 53) of the exterior film 50 that face each other.

[0056] The first sealed portion 91 includes a portion where the first edge 50A and the second edge 50B of the exterior film 50 shown in FIG. 3 are overlapped. The first sealed portion 91 extends in the longitudinal direction (FB direction) of the exterior body 40. The position where the first sealed portion 91 is formed in the exterior body 40 can be selected arbitrarily. In the present embodiment, the base 91X of the first sealed portion 91 is preferably located on the side 43 at the boundary between the first surface 41A and the second surface 42A of the exterior body 40. The base 91X of the first sealed portion 91 may be located on any surface of the exterior body 40. From the viewpoint of configuring the power storage device 10 compactly, it is preferable that the first sealed portion 91 is folded onto, for example, the first surface 41A or the second surface 42A of the exterior body 40 when the power storage device 10 is in use.

[0057] In this embodiment, a portion including the end of the exterior film 50 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 a second sealing portion 92 (see FIGS. 6 and 7 ). In this embodiment, the second sealing portion 92 has a crimped portion 92X where the first protrusion 70B of the covering body 70 is crimped to the recess 82A of the lid main body 80. The crimped portion 92X is a portion where the covering body 70 and the lid main body 80 are mechanically joined by utilizing plastic deformation of the covering body 70 and the lid main body 80. The crimped portion 92X is preferably formed by plastic deformation of the covering body 70 and the lid main body 80 without using other members such as rivets. In this embodiment, the first protrusion 70B is formed along the entire edge of the opening 70YA. Therefore, the crimped portion 92X is formed along the entire opening 70YA. The exterior film 50 does not have to be disposed on the first protruding portion 70B. The crimped portion 92X may be formed to include the portion where the exterior film 50 is sandwiched between the first main body portion 70A and the lid main body 80, or the crimped portion 92X may be formed only in the portion where the exterior film 50 is sandwiched between the first main body portion 70A and the lid main body 80.

[0058] <1-2. Method for manufacturing electricity storage devices> FIG. 8 is a flowchart showing an example of a method for manufacturing the electricity storage device 10. The method for manufacturing the electricity 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. The first step to the sixth step are performed, for example, by a manufacturing apparatus for the electricity storage device 10. At least a part of the first step to the sixth step may be performed by an operator. Note that the first step to the sixth step are names of the steps in the method for manufacturing the electricity storage device 10 specified for convenience, 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 process of step S1, the manufacturing device places a pair of lid bodies 80 on the sides of the electrode body 20, and electrically connects the electrode body 20 and the lid bodies 80 together.

[0060] The second step of step S2 is carried out after the first step. In the second step, the manufacturing device wraps the electrode body 20 and the pair of lid bodies 80 with the exterior film 50.

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

[0062] The fourth step of step S4 is performed after the third step. In the fourth step, the manufacturing apparatus fits the lid main body 80 into the opening 70YA of the covering body 70. By completing the fourth step, a portion of the exterior film 50 including the end in the FB direction and the end seal portion are sandwiched between the inner surface of the opening 70YA of the covering body 70 and the covering portion 83 of the lid main body 80.

[0063] The fifth step of step S5 is performed after the fourth step. In the fifth step, the manufacturing apparatus forms the second sealing portion 92 by crimping the lid main body 80 and the first protruding portion 70B of the cover 70 together.

[0064] The sixth step of step S6 is performed before or after the fifth step. In the sixth step, the manufacturing apparatus forms a first sealed portion 91 by heat-sealing the heat-sealable resin layer 53 in a portion including the first edge 50A of the exterior film 50 and the heat-sealable resin layer 53 in a portion including the second edge 50B.

[0065] <1-3. Actions and Effects of Electricity Storage Devices> The electricity storage device 10 has a second sealing portion 92 in which the exterior film 50 is sandwiched between the cover 70 and the lid main body 80, and therefore the exterior film 50 is unlikely to come off the lid body 60. Therefore, the electricity storage device 10 has high sealing performance.

[0066] [2. Modifications] The above-described embodiments are examples of possible forms of the electricity storage device, lid, and method for manufacturing an electricity storage device according to the present invention, and are not intended to limit the forms. The electricity storage device, lid, and method for manufacturing an electricity storage device according to the present invention may take forms different from those exemplified in the embodiments. Examples include forms in which part of the configuration of the embodiments is replaced, modified, or omitted, or forms in which a new configuration is added to the embodiments. Some examples of modified embodiments are shown below. Note that the following modified forms can be combined with each other as long as there is no technical contradiction.

[0067] <2-1. First modified example> In the above embodiment, the configuration of the lid main body 80 can be modified. Figure 9 is a perspective view of a lid main body 180 included in the electricity storage device 10 of a first modified example. The lid main body 180 includes a second main body portion 180A and a second protrusion portion 180B.

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

[0069] FIG. 10 is a cross-sectional view of the power storage device 10 of the first modified example. The power storage device 10 of the first modified example includes a second sealing portion 192. In the second sealing portion 192, a portion including an end portion of the exterior film 50 in the FB direction is sandwiched between the first protrusion 70B of the cover 70 and the second protrusion 180B of the lid main body 180. The second sealing portion 192 has a crimped portion 192X. The crimped portion 192X is a portion formed by bending the first protrusion 70B, the second protrusion 180B, and the exterior film 50 so that they approach the second surface 82 of the second main body portion 180A and then crushing the folded portion. That is, the crimped portion 192X is formed by performing bending and crimping.

[0070] <2-2. Second modified example> In the above embodiment, the configuration of the second sealing portion 92 can be modified. FIG. 11 is a cross-sectional view of an electric storage device 10 according to a second modification. The electric storage device 10 according to the second modification may include an adhesion assisting member 100 disposed between the first protrusion 70B and the lid main body 80 in the second sealing portion 92. The adhesion assisting member 100 is a member that improves adhesion between the first protrusion 70B and the lid main body 80 after the crimped portion 92X is formed in the second sealing portion 92. The adhesion assisting member 100 is made of, for example, a foam material, a sponge, a resin, or a rubber. The adhesion assisting member 100 may be disposed between the cover 70 and the exterior film 50, or may be disposed between the exterior film 50 and the lid main body 80. The adhesion assisting member 100 may be disposed both between the cover 70 and the exterior film 50 and between the exterior film 50 and the lid main body 80. The adhesion assisting member 100 may be formed such that the element placed between the covering body 70 and the exterior film 50 and the element placed between the exterior film 50 and the lid main body 80 are either integrated or separate.

[0071] <2-3.Third modified example> 12 , the electricity storage device 10 according to a third modified example, which is a further modified example of the first modified example, may include a close contact assisting member 200. The specifications of the close contact assisting member 200 are the same as those of the close contact assisting member 100. The close contact assisting member 100 may be disposed between the cover 70 and the exterior film 50, or may be disposed between the exterior film 50 and the lid main body 180.

[0072] <2-4. Fourth Modification> In the first modified example, the cover 70 or the cover main body 180 may be omitted from the cover 60. FIG. 13 is a cross-sectional view of the electricity storage device 10 of a fourth modified example, which is a further modified example of the first modified example. In the example shown in FIG. 13, the cover 70 is omitted from the cover 60. The second sealing portion 192 may be formed by crimping the second protruding portion 180B of the cover main body 180 and the end of the exterior film 50. When the lid main body 180 is omitted from the cover 60, the second sealing portion 192 may be formed by crimping the first protruding portion 70B of the cover 70 and the end of the exterior film 50.

[0073] <2-5. Fifth Modification> In the above embodiment, the manufacturing method of the electricity storage device 10 can be changed as desired. For example, the lid body 80 in a state where it is temporarily joined to the exterior film 50, or the lid body 80 in a state where it is not temporarily joined to the exterior film 50, may be fitted into the covering body 70, 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 in a state where it is temporarily joined to the exterior film 50, or the covering body 70 in a state where it is not temporarily joined to the exterior film 50, and then the second sealing portion 92 may be formed.

[0074] <2-6. Sixth Variation> In the above embodiment, the exterior film 50 is disposed over substantially the entire first protrusion 70B. However, the exterior film 50X may not be disposed over at least a portion of the first protrusion 70B. FIG. 14 is a cross-sectional view of an electricity storage device according to a sixth modified example. In the example shown in FIG. 14, the exterior film 50 is not disposed over the first protrusion 70B. In the sixth modified example, the crimped portion 92X may be formed to include the portion where the exterior film 50 is sandwiched between the first main body 70A and the lid main body 80, or the crimped portion 92X may be formed only over the portion where the exterior film 50 is sandwiched between the first main body 70A and the lid main body 80. In the sixth modified example, in order to improve the sealing performance of the second sealing portion 92, after the crimped portion 92X is formed, at least a portion of the second sealing portion 92 is preferably subjected to a bonding process depending on the materials constituting the cover 70 and the lid main body 80. The bonding process may be, for example, welding. The welding may be, for example, pulse heat, laser welding, arc welding, electron beam welding, gas welding, pressure welding, or brazing. The joining process may be performed partially on the second sealing portion 92. The unjoined portions of the second sealing portion 92 have lower joining strength than the joined portions. Therefore, when the internal pressure of the exterior body 40 increases, the unjoined portions of the second sealing portion 92 will separate before the joined portions. This allows the location from which gas is released to be limited to some extent. In another example, the first protrusion 70B and the lid main body 80 of the second sealing portion 92 may be joined by an adhesive or the like in addition to being mechanically joined. To limit the location from which gas is released to some extent when the internal pressure of the exterior body 40 increases, the first protrusion 70B and the lid main body 80 may be partially joined by an adhesive or the like. The sixth modification can be similarly applied to the first to fourth modifications.

[0075] <2-7. Seventh Variation> In the above embodiment, the exterior film 50 may have a portion in the FB direction where only the barrier layer 52 is exposed. FIG. 15 is a cross-sectional view showing an example of the layer structure of the exterior film 50 included in the electricity storage device 10 of the seventh modified example. In the example shown in FIG. 15, the barrier layer 52 has a protruding portion 52X that protrudes further than the base material layer 51 and the thermally adhesive resin layer 53 in the FB direction. The protruding portion 52X may be formed only on one lid body 60 side in the FB direction, or only on the other lid body 60 side. The second sealing portion 92 preferably includes the protruding portion 52X. When the exterior film 50 has the protruding portion 52X and the barrier layer 52 includes a layer made of a metal material, the second sealing portion 92 is preferably subjected to a joining process depending on the materials constituting the cover 70 and the lid main body 80 after the crimping portion 92X is formed, in order to improve the sealing performance of the second sealing portion 92. The joining process is welding. The welding may be, for example, pulse heat, laser welding, arc welding, electron beam welding, gas welding, pressure welding, or brazing. In another example, the first protrusion 70B, the protrusion 52X, and the lid main body 80 may be joined by an adhesive or the like in addition to being mechanically joined.

[0076] In the seventh variant, when the protrusion 52X is formed on one side of the lid body 60 and on the other side of the lid body 60 in the FB direction, the lid body 60 has a structure that prevents electrical conduction between the part connected to the electrode of one lid body 60 and the part connected to the electrode of the other lid body 60.

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

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

[0079] The insulating portion 620 insulates the lid main body 80X from the current extraction portion 610. Therefore, even when the barrier layer 52 and a pair of lid bodies 60 are joined, the current extraction portion 610 of one lid body 60 is not electrically connected to the current extraction portion 610 of the other lid body 60. The material constituting the insulating portion 620 can be selected arbitrarily as long as it can insulate the lid main body 80X from the current extraction portion 610. The material constituting the insulating portion 620 is, for example, an elastomer, a resin material, or ceramic. The ceramic is, for example, glass, oxide, nitride, carbonate, or hydroxide. The insulating portion 620 is arranged to fill the gap between the current extraction portion 610 and the inner surface of the through-hole 80Y. Note that in the seventh modification, the first sealing portion 91 may be formed by joining the protruding portions 52X on opposing surfaces of the exterior film 50. The seventh modified example can be similarly applied to the first to fourth modified examples.

[0080] <2-8. Eighth Variation> In the above embodiment, it is possible to change the configuration of the exterior film 50. Fig. 17 is a cross-sectional view showing an example of the layer configuration of an exterior film 50X provided in the electricity storage device 10 of the eighth modified example.

[0081] The exterior film 50X is a laminate film including 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 so that the first barrier layer 710 and the second barrier layer 720 are not electrically connected to each other. In the eighth modification, the first barrier layer 710, the insulating layer 730, and the second barrier layer 720 are laminated in this order from the outside of the exterior body 40 toward the electrode body 20. The first barrier layer 710 and the second barrier layer 720 are composed of a metal material.

[0082] The first barrier layer 710 is bonded 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 metal material contained in the material forming the first barrier layer 710 is the same as the metal material contained in the material forming the lid 60 connected to the positive electrode. The second sealing portion 92 is configured to include an end portion of the first barrier layer 710.

[0083] The second barrier layer 720 is bonded 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 contained in the material constituting the second barrier layer 720 is the same as the metal material contained in the material constituting the lid 60 connected to the negative electrode. The second sealing portion 92 is configured to include an end portion of the second barrier layer 720.

[0084] The insulating layer 730 insulates the first barrier layer 710 from the second barrier layer 720 so that they are not electrically connected to each other. Any material can be selected as the material for the insulating layer 730 as long as it can insulate the first barrier layer 710 from the second barrier layer 720. The material for the insulating layer 730 is, for example, a resin, an elastomer, or a ceramic. The ceramic is, for example, a glass, an oxide, a nitride, a carbonate, or a hydroxide. The material for the insulating layer 730 may be a combination of multiple materials. From the viewpoint of suitably insulating the first barrier layer 710 from the second barrier layer 720, it is preferable that the material for the insulating layer 730 contains an insulating filler.

[0085] The resin is, for example, a thermoplastic resin such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenolic resin, fluororesin, or modified products of these resins. From the viewpoint of moisture barrier properties, it is preferable to use a thermoplastic resin such as a fluororesin or modified products of a fluororesin.

[0086] The ceramic is, for example, an oxide or nitride. The oxide is, for example, magnesium oxide, silicon oxide, aluminum oxide, or tin oxide. These oxides have moisture barrier properties.

[0087] The nitride is, for example, aluminum nitride, boron nitride, or silicon nitride. From the viewpoint of moisture barrier properties, it is preferable to use silicon nitride.

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

[0089] The exterior film 50 preferably includes an overlapping portion 700X, which is a portion where the first barrier layer 710, the insulating layer 730, and the second barrier layer 720 overlap in a plan view. When the exterior 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 modification, the overlapping portion 700X is formed so as to cover substantially 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 connected to the positive electrode.

[0091] The second barrier layer 720 extends in the FB direction further toward the lid body 60 connected to the negative electrode than the first barrier layer 710 and the insulating layer 730. From the viewpoint of preventing a short circuit between the second barrier layer 720 and the electrode body 20, it is preferable that another insulating layer be laminated on the surface of the second barrier layer 720 opposite to the surface on which the insulating layer 730 is laminated.

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

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

[0094] In the eighth modification, the first barrier layer 710 and the second barrier layer 720 are insulated by the insulating layer 730, and therefore the lid body 60 connected to the positive electrode and the lid body 60 connected to the negative electrode are not electrically connected.

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

[0096] FIG. 19 is a cross-sectional view showing an example of the layer structure of an exterior film 50Z included in an electricity storage device 10 according to yet another modification of the eighth modification. As shown in FIG. 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 FIG. 19, the first barrier layer 710 and the second barrier layer 720 are laminated on the surface of the insulating layer 730 opposite the surface facing the electrode assembly 20. The first barrier layer 710 and the second barrier layer 720 are preferably laminated on the insulating layer 730 so as to form a gap therebetween in the FB direction so as not to be electrically connected to each other. If the material constituting the insulating layer 730 does not have moisture barrier properties, an arbitrary layer containing a material having moisture barrier properties may be laminated between the first barrier layer 710 and the second barrier layer 720 of the insulating layer 730. 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 assembly 20. In addition, in the eighth variant and related variants, 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 on the facing surfaces of the exterior film 50 together.

[0097] <2-9. 9th Variation> In the above embodiment, the metallic elements of the covering body 70 and the lid main body 80 may have micro-irregularities formed on their surfaces in contact with the resin-containing portions of the exterior film 50, for example, by laser processing. The metallic elements of the covering body 70 and the lid main body 80, on which the micro-irregularities are formed, are more firmly bonded to the resin-containing portions of the exterior film 50, such as the base layer 51 and the heat-sealable resin layer 53, by an anchor effect. This improves the sealing performance of the energy storage device 10. The covering body 70, the lid main body 80, and the exterior film 50 may be joined by welding. Examples of welding include pulse heat, laser welding, arc welding, electron beam welding, gas welding, pressure welding, and brazing. When at least one of the covering body 70 and the lid main body 80 is made of a resin material, the protrusion 52X in the seventh modification may have micro-irregularities formed on at least a portion of its surface in contact with the resin-containing elements by laser processing. The ninth modification can be similarly applied to the eighth modification.

[0098] <2-10. 10th Variation> In the above embodiment, the exterior film 50 of the electricity storage device 10 may protrude outward beyond at least one of the two lid bodies 60 in the FB direction. The electrode body 20 is sealed by closing the portion of the exterior film 50 that protrudes outward beyond the lid body 60. The portion of the exterior film 50 that protrudes beyond the lid body 60 may be folded inward so that the outer surfaces of the exterior films 50 come into contact with each other, as in a Goebel-top container, or may be folded toward any surface of the exterior body 40, as in a brick container.

[0099] <2-11. 11th Variation> In the above embodiment, the exterior body 40 may not have one of the two lid bodies 60. In this modification, in the FB direction, in the portion of the exterior body 40 where the lid body 60 is omitted, the electrode body 20 is sealed by closing the portion of the exterior film 50 that protrudes outward beyond the electrode body 20. As in the tenth modification, the portion of the exterior film 50 that protrudes outward beyond the electrode body 20 may be folded like a Goebel-top container or a brick container.

[0100] <2-12. 12th Variation> In the above embodiment, the outer shape of the exterior body 40 can be changed as desired. The outer shape of the exterior body 40 may be a cylinder, a prism, or a cube.

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

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

Claims

1. An electrode body; an exterior body that seals the electrode body, The exterior body is an exterior film that wraps the electrode body; a lid that seals the electrode body together with the exterior film, The lid body is entirely disposed to the side of the electrode body, a coating (excluding films) comprising at least one of a resin material and a metal material; a lid body joined to the cover body, The exterior body has a sealing portion in which the exterior film is sandwiched between the cover body and the lid main body. Energy storage device.

2. The sealing portion has a crimping portion where the cover and the lid body are crimped together. The electricity storage device according to claim 1 .

3. the covering body has a first main body portion and a first protrusion protruding from the first main body portion, the lid body has a second body portion and a second protrusion portion protruding from the second body portion, The sealing portion is configured by folding the exterior film while sandwiching it between the first protruding portion and the second protruding portion. The electricity storage device according to claim 1 or 2.

4. A contact assisting member is disposed between the cover and the lid body. The electricity storage device according to claim 1 or 2.

5. A lid body used as an exterior body of an electricity storage device, a coating (excluding films) comprising at least one of a resin material and a metal material; a lid body including a metal material and joined to the cover body, An exterior film constituting the exterior body is sandwiched between the cover body and the lid body, The cover and the lid body have a gap for sandwiching the exterior film therebetween, The lid body is configured so that the entire lid body is disposed to the side of the electrode body of the power storage device. Lid body.

6. A method for manufacturing an electricity storage device, comprising: The electricity storage device is An electrode body; an exterior body that seals the electrode body, The exterior body is an exterior film that wraps the electrode body; a lid that seals the electrode body together with the exterior film, The lid body is entirely disposed to the side of the electrode body, a coating (excluding films) comprising at least one of a resin material and a metal material; a lid body joined to the cover body, The method for manufacturing the electricity storage device includes: forming a sealing portion in which the exterior film is sandwiched between the cover and the lid body. A method for manufacturing an electricity storage device.

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