Lid body, and power storage device

Abstract

To provide a lid body and a power storage device that can suitably bind the ends of a collector.SOLUTION: A lid body is used for an exterior body of a power storage device, and includes a lid main body formed by including metal material. The lid main body has storage parts that store the ends of a collector of the power storage device.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a lid and 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, a current collector, an electrode terminal, and an exterior body that seals the electrode assembly and the current collector. The exterior body includes an exterior film that encases the electrode assembly, and a lid that is joined to the exterior film. The lid is made of, for example, a metal material, and has a through hole formed therein through which the electrode terminal is inserted. One end of the current collector is connected to the electrode assembly, and the other end is connected to the electrode terminal. [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 order to suitably output electric power, it is preferable that the ends of the current collector are suitably constrained. In the above-described electricity storage device, there is room for improvement in terms of suitably constraining the ends of the current collector.

[0005] An object of the present invention is to provide an electricity storage device that can suitably restrain the end of a current collector, and a lid body used in this electricity storage device. [Means for solving the problem]

[0006] A lid body according to a first aspect of the present invention is a lid body used as an exterior body for an electricity storage device, and includes a lid main body comprising a metal material, and the lid main body has a storage portion that stores an end of a current collector of the electricity storage device.

[0007] A lid body according to a second aspect of the present invention is the lid body according to the first aspect, wherein the storage portion is a recess that does not penetrate the lid body.

[0008] A lid according to a third aspect of the present invention is the lid according to the first or second aspect, further comprising a cover that contains a resin material and covers a part of the lid body.

[0009] A lid body according to a fourth aspect of the present invention is a lid body according to the third aspect, wherein the lid body has a covering portion that is covered by the covering portion, and the covering portion has at least one of a through hole, a recessed portion recessed on the opposite side to the covering portion, or a protrusion that protrudes toward the covering portion.

[0010] A lid according to a fifth aspect of the present invention is the lid according to the third aspect, wherein the lid body has a covering portion that is covered by the covering body, and at least a part of the covering portion has a rough surface.

[0011] An electricity storage device according to a sixth aspect of the present invention comprises an electrode body and an exterior body that seals the electrode body, the exterior body including an exterior film that wraps the electrode body and a lid body that is joined to the exterior film, and a lid main body that contains a metal material, and the lid main body has a storage portion that stores an end of a current collector of the electricity storage device. [Effects of the Invention]

[0012] According to the lid and the electricity storage device of the present invention, the end of the current collector can be suitably restrained. [Brief explanation of the drawings]

[0013] [Figure 1A] FIG. 1 is a perspective view of an electricity storage device according to an embodiment. [Figure 1B] 1B is a diagram showing a method for measuring the seal strength of the second sealing portion of the electricity storage device in FIG. 1A. FIG. [Figure 2] 1B is a cross-sectional view showing the layer structure of an exterior film included in the electricity storage device of FIG. 1A. [Figure 3]FIG. 1B is a diagram showing the state in which the exterior film provided on the electricity storage device of FIG. 1A is unfolded. [Figure 4] FIG. 1B is a cross-sectional view taken along line D4-D4 in FIG. 1A. [Figure 5] FIG. 5 is a side view of the lid body in a state where the exterior film in FIG. 4 is omitted. [Figure 6] FIG. 5 is a plan view of the lid body in FIG. 4 with the exterior film omitted. [Figure 7] FIG. 5 is a perspective view of the front side of the lid body of the lid body of FIG. 4. [Figure 8] FIG. 8 is a perspective view of the rear side of the lid body of FIG. 7. [Figure 9] 1B is a cross-sectional view taken along line D9-D9 in FIG. 1A. [Figure 10] 1B is a flowchart showing an example of a manufacturing process for the electricity storage device of FIG. 1A. [Figure 11] FIG. 10 is a perspective view of the rear side of the lid body of the second modified example. [Figure 12] Enlarged view of part X in Figure 11. [Figure 13] FIG. 11 is a perspective view of the rear side of the lid body of the third modified example. [Figure 14] FIG. 11 is a cross-sectional view of an electricity accumulation device including a lid body according to a fourth modified example. [Figure 15] FIG. 11 is a cross-sectional view of an electricity accumulation device including a lid body according to a fifth modified example. [Figure 16] FIG. 13 is a cross-sectional view of an electricity accumulation device according to a seventh modified example. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an electricity storage device according to one 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.

[0015] [Embodiment] <1-1. Configuration of the power storage device> FIG. 1A is a perspective view schematically showing an electricity storage device 10 of an embodiment. FIG. 1B is a diagram relating to a method for measuring the seal strength of a second sealing portion 92 of the electricity storage device 10 of FIG. 1. FIG. 2 is a cross-sectional view showing the layer structure of an exterior film 50 included in the electricity storage device 10 of FIG. 1A. FIG. 3 is a view showing the exterior film 50 included in the electricity storage device 10 of FIG. 1A in an unfolded state. FIG. 4 is a cross-sectional view taken along line D4-D4 in FIG. 1A. FIG. 5 is a side view of a lid body 60 included in the electricity storage device 10 of FIG. 1A. FIG. 6 is a plan view of the lid body 60 of FIG. 5. FIG. 7 is a perspective view of the front side of a lid main body 70 included in the lid body 60 of FIG. 4. FIG. 8 is a perspective view of the back side of the lid main body 70 of FIG. 7. FIG. 9 is a cross-sectional view taken along line D9-D9 in FIG. 1A. 1A, 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 UDLRFB are the same in the subsequent figures.

[0016] The electricity storage device 10 includes an electrode assembly 20 including a current collector 30 and an exterior housing 40. The electrode assembly 20 includes electrodes (positive and negative electrodes) constituting an electricity storage member such as a lithium-ion battery, capacitor, all-solid-state battery, semi-solid battery, quasi-solid battery, polymer battery, all-resin battery, lead-acid battery, nickel-metal hydride battery, nickel-cadmium battery, nickel-iron battery, nickel-zinc battery, silver oxide-zinc battery, metal-air battery, polycation battery, or capacitor, as well as a separator. In this embodiment, the electrode assembly 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 assembly 20 may have a cylindrical or polygonal prism shape, for example.

[0017] One end 31 of the current collector 30 (see FIG. 9) is connected to the lid 60.

[0018] The exterior body 40 seals the electrode body 20. The exterior body 40 includes an exterior film 50 and a lid 60. The exterior film 50 wraps the electrode body 20 so as to have an opening 40A. In this embodiment, the exterior film 50 is wrapped around the electrode body 20 so as to have the opening 40A. The lid 60 is placed on the side of the electrode body 20 so as to close the opening 40A. Note that the electrode body 20 may be housed inside the exterior film 50 that is configured in a cylindrical shape so as to form the opening 40A, and the opening 40A may be closed by the lid 60.

[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 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. The thickness of the base layer 51 is preferably, for example, 5 to 300 μm, and more preferably 5 to 150 μm, from the viewpoint of film strength.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] 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 9 to 200 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 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 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.

[0028] 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.

[0029] 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.

[0030] 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 provides heat-sealing properties 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. From the viewpoints of sealability and strength, the thickness of the heat-sealable resin layer 53 is preferably, for example, 20 to 300 μm, and more preferably 40 to 150 μm.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 5 and 6, the lid body 60 has, for example, a rectangular parallelepiped shape as a whole. The lid body 60 has a lid main body 70 containing a metal material and a cover 80 containing a resin material that covers a portion of the lid main body 70. The lid body 60 can be manufactured, for example, by injection molding the cover 80 onto the lid main body 70.

[0036] The metal material constituting the lid body 70 can be selected arbitrarily. The metal material constituting the lid body 70 is, for example, aluminum, aluminum alloy, nickel, copper, or copper alloy. For example, when the electrode body 20 is a lithium-ion battery, the lid body 70 connected to the positive electrode is preferably made of aluminum or an aluminum alloy. The lid body 70 connected to the negative electrode is preferably made of nickel, copper, or a copper alloy. The material constituting the lid body 70 connected to the negative electrode may be nickel-plated copper. The material constituting the lid body 70 may include recycled metal materials. The lid body 70 has a base 71 and a covering portion 72.

[0037] The lid body 70 is made of a metal material. Here, "made of a metal material" means that, when the entire material constituting the lid body 70 is taken as 100% by mass, the content of 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 lid body 70 can contain materials other than metal materials in addition to metal materials.

[0038] When the lid body 70 is made of a metal material, it preferably has the corrosion-resistant coating described in connection with the barrier layer 52. The lid body 60 may include at least one of an adhesive film and an adhesive layer between the lid body 70 and the cover 80 to suitably bond them together. The adhesive film or adhesive layer may be a single layer or multiple layers, and preferably contains at least a resin material having a polar group. The adhesive layer can be formed by dip coating, a dispenser, inkjet printing, spraying, screen printing, or the like.

[0039] 7 and 8 is, for example, a rectangular plate and has a first surface 71A and a second surface 71B. The first surface 71A faces the electrode assembly 20. The second surface 71B is the surface opposite the first surface 71A. From the viewpoint of suitably restraining the end 31 (see FIG. 9) of the current collector 30 and from the viewpoint of shortening the distance between the electrode assembly 20 and the lid 60 to improve the volume density, the base 71 is formed with a storage portion 71X that stores the end 31 of the current collector 30.

[0040] The shape of the storage portion 71X can be selected arbitrarily as long as it can accommodate at least the end portion 31 of the current collector 30. In this embodiment, the storage portion 71X is a recess recessed from the first surface 71A toward the second surface 71B. The storage portion 71X does not penetrate the lid main body 70. The opening of the storage portion 71X faces the electrode assembly 20. The bottom of the storage portion 71X protrudes from the second surface 71B toward the outside. The storage portion 71X extends in the LR direction. The number of storage portions 71X formed in the base 71 can be selected arbitrarily. In the example shown in FIG. 8, two storage portions 71X are formed in the base 71. The two storage portions 71X are aligned in the UD direction. One, three, or more storage portions 71X may be formed in the base 71. The end portion 31 of the current collector 30 is joined to an arbitrary location inside the storage portion 71X by, for example, ultrasonic welding or laser welding. The end 31 of the current collector 30 and the housing portion 71X may be joined by screw fastening, press fitting, shrink fitting, caulking welding, pressure welding, brazing, or an adhesive. When the end 31 of the current collector 30 and the housing portion 71X are joined by an adhesive, it is sufficient that at least one of the end 31 of the current collector 30 and the housing portion 71X is conductive in the portion joined by the adhesive and the portion other than the portion joined by the adhesive. In this embodiment, the lid main body 70 is made of a metal material and therefore functions as an electrode terminal. Therefore, the electricity storage device 10 has fewer components than conventional electricity storage devices. Note that the lid main body 70 may have an electrode terminal joined to, for example, the bottom of the housing portion 71X.

[0041] The covering portion 72 is covered by a covering body 80. The covering portion 72 is frame-shaped and rises from the first surface 71A of the base portion 71. The covering portion 72 has a first covering portion 72A, a second covering portion 72B, a third covering portion 72C, and a fourth covering portion 72D. The first covering portion 72A forms the upper surface of the lid main body 70. The first covering portion 72A extends in a first direction (in this embodiment, the LR direction) when viewed from the front of the lid main body 70. The second covering portion 72B and the third covering portion 72C are connected to the first covering portion 72A and form the side surfaces of the lid main body 70. The second covering portion 72B and the third covering portion 72C 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 70. In this embodiment, the first direction and the second direction are perpendicular to each other when viewed from the front of the lid main body 70. The first direction and the second direction do not have to be orthogonal in a front view of the lid body 70. The fourth covering portion 72D forms the lower surface of the lid body 70. The fourth covering portion 72D extends in the first direction (the LR direction in this embodiment) in a front view of the lid body 70.

[0042] At least a portion of the front surface 72X of the covering portion 72 is covered by the covering body 80. In this embodiment, the entire front surface 72X of the covering portion 72 is covered by the covering body 80. In order to increase the bonding strength between the lid body 70 and the covering body 80, it is preferable that at least a portion of the back surface 72Y of the covering portion 72 is covered by the covering body 80. In other words, it is preferable that the covering portion 72 is covered such that the front surface 72X and the back surface 72Y are sandwiched between the covering bodies 80. In this embodiment, the entire back surface 72Y is covered by the covering body 80.

[0043] In order to further increase the bonding strength between the lid main body 70 and the covering body 80, it is preferable that a through hole 72Z be formed in the covering portion 72. The shape of the through hole 72Z in a plan view can be selected arbitrarily. In this embodiment, the shape of the through hole 72Z in a plan view is rectangular. The shape of the through hole 72Z in a plan view may be circular, elliptical, square, or polygonal. When the front surface 72X and the back surface 72Y of the covering portion 72 are covered with the covering body 80, the covering body 80 covering the front surface 72X of the covering portion 72 and the covering body 80 covering the back surface 72Y of the covering portion 72 are connected via the covering body 80 present in the through hole 72Z. This further increases the bonding strength between the lid main body 70 and the covering body 80. The number of through holes 72Z formed in the covering portion 72 can be selected arbitrarily. 7, five through holes 72Z are formed in each of the first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D. One to four, or six or more through holes 72Z may be formed in each of the first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D. The numbers of through holes 72Z formed in the first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D may be different from one another. Some of the first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D may not have through holes 72Z formed therein.

[0044] The covering body 80 shown in FIG. 4 has a lid seal portion 81. The lid seal portion 81 is heat-sealed to the heat-fusible resin layer 53 of the exterior film 50. The lid seal portion 81 includes a first seal surface 81A, a second seal surface 81B, a third seal surface 81C, and a fourth seal surface 81D. The first seal surface 81A forms the top surface of the lid body 60. The first seal surface 81A extends in a first direction (in this embodiment, the LR direction) when viewed from the front of the lid body 60. The second seal surface 81B and the third seal surface 81C are connected to the first seal surface 81A and form the side surfaces of the lid body 60. The second seal surface 81B and the third seal surface 81C 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 body 60. In this embodiment, the first direction and the second direction are perpendicular to each other when viewed from the front of the lid body 60. The first direction and the second direction do not have to be perpendicular to each other in a front view of the lid 60. The fourth sealing surface 81D forms the lower surface of the lid 60. The fourth sealing surface 81D extends in the first direction (the LR direction in this embodiment) in a front view of the lid 60.

[0045] When the lid body 60 is plate-shaped, it is preferable that the lid body 60 has a certain thickness so that deformation of the exterior body 40 is suppressed even when the electricity storage device 10 is placed on top of it. From another perspective, when the lid body 60 is plate-shaped, it is preferable that the lid seal portion 81 of the lid body 60 has a certain thickness so that the lid seal portion 81 of the lid body 60 and the exterior film 50 can be heat-sealed appropriately when forming the second sealing portion 92 described below. The minimum thickness of the lid seal portion 81 of the lid body 60 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum thickness of the lid seal portion 81 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 lid seal portion 81 of the lid body 60 may be 20 mm or more. The preferred ranges for the thickness of the lid seal portion 81 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. In this embodiment, when the lid body 60 is described as being plate-shaped, this does not include embodiments in which the lid body 60 is composed solely of a film as defined by the JIS (Japanese Industrial Standards) [Packaging Terminology] standard. The thickness of the lid seal portion 81 of the lid body 60 may vary depending on the region of the lid body 60. When the thickness of the lid seal portion 81 of the lid body 60 varies depending on the region, the thickness of the lid seal portion 81 of the lid body 60 is the thickness of the thickest portion.

[0046] The lid seal portion 81 further includes boundaries 82, 83, 84, and 85. The boundary 82 is the boundary between the first seal surface 81A and the second seal surface 81B. The boundary 83 is the boundary between the first seal surface 81A and the third seal surface 81C. The boundary 84 is the boundary between the fourth seal surface 81D and the second seal surface 81B. The boundary 85 is the boundary between the fourth seal surface 81D and the third seal surface 81C. The shapes of the boundaries 82 to 85 may be angular, or may be rounded by applying a rounding process. In this embodiment, the boundaries 82 to 85 are angular.

[0047] The covering 80 is made of a resin material. Here, "made of a resin material" means that, when the entire material constituting the covering 80 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 80 can contain materials other than the resin material in addition to the resin material.

[0048] 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, heat-sealable resins such as polyester and polyolefin are preferred, with polyolefin being more preferred. When the resin material is a resin, the covering 80 may be molded using any molding method.

[0049] The resin material contained in the material constituting the coating 80 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 80 preferably contains multiple types of amide-based lubricants. Furthermore, the resin material contained in the material constituting the coating 80 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 80 may be a polyolefin resin to which a propylene-based elastomer having a melting point higher than 150°C has been added.

[0050] 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.

[0051] 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.

[0052] 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 covering 80 against temperature changes can be improved.

[0053] The melt mass flow rate of the resin material contained in the material constituting the coating 80 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.

[0054] In this embodiment, the first sealing portion 91 is formed by wrapping the exterior film 50 around the electrode body 20 so as to have an opening 40A, and then heat-sealing the opposing surfaces of the exterior film 50 (heat-fusible resin layers 53).

[0055] The first sealed portion 91 is formed by heat-sealing a portion including the first edge 50A and a portion including the second edge 50B of the exterior film 50 shown in FIG. 3 . The first sealed portion 91 extends in the longitudinal direction (FB direction) of the exterior body 40. The position at which 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 41 and the second surface 42 of the exterior body 40. The first surface 41 has a larger area than the second surface 42. The base 91X of the first sealed portion 91 may be located on any surface of the exterior body 40. In the present embodiment, the first sealed portion 91 protrudes outward beyond the electrode body 20 in a plan view. The first sealed portion 91 may be folded, for example, toward the second surface 42 or the first surface 41 of the exterior body 40.

[0056] In this embodiment, the second sealing portion 92 is formed by heat-sealing the heat-sealable resin layer 53 of the exterior film 50 and the lid seal portion 81 of the lid body 60. Hereinafter, the seal strength between the heat-sealable resin layer 53 of the exterior film 50 and the lid seal portion 81 of the lid body 60 may be referred to as the seal strength of the second sealing portion 92. The seal strength of the second sealing portion 92 is the seal strength between the heat-sealable resin layer 53 and the lid body 60 at the long side portion of the lid seal portion 81, i.e., the lid seal portion 81 extending in the L-R (width) direction in FIG. 1A .

[0057] The seal strength of the second sealing portion 92 is measured as follows. First, a slit is made in the portion of the exterior film 50 that constitutes the first surface 41 of the exterior body 40, forming three strip-shaped members 41X, 41Y, and 41Z aligned in the L-R direction (see the two-dot chain lines in FIG. 1B). The width of the three strip-shaped members 41X, 41Y, and 41Z in the L-R direction is 15 mm. The ends of the strip-shaped members 41X, 41Y, and 41Z are joined to the lid body 60 at the second sealing portion 92. The length of the lid body 60 in the L-R direction is 45 mm or more. Next, the end of each of the strip-shaped members 41X, 41Y, and 41Z opposite the end joined to the lid body 60 is pulled upward in the UD direction (away from the first surface 41B), thereby measuring the seal strength of each of the strip-shaped members 41X, 41Y, and 41Z. The distance between the zippers in the UD direction is 10 mm. The seal strength of the strip-shaped members 41X, 41Y, and 41Z is the peak value of each seal strength. In this embodiment, the seal strength of the second sealing portion 92 is the average value of the seal strengths of the strip-shaped members 41X, 41Y, and 41Z. When the length of the lid body 60 in the L-R direction is less than 45 mm, three strip-shaped members with an arbitrary width X mm, less than 15 mm, are formed, and the seal strengths of the three strip-shaped members are measured using the same method as when the length of the lid body 60 in the L-R direction is 45 mm or more. The obtained seal strengths are each divided by the arbitrary width X mm and multiplied by 15 to convert them to the seal strengths of the three strip-shaped members in a 15 mm width. The seal strength of the second sealing portion 92 is the average value of the seal strengths of the three strip-shaped members converted to a 15 mm width. Note that when the lid body 60 is divided into multiple parts including long and short sides, the seal strength of the second sealing portion 92 is the seal strength of the long sides of the lid seal portions 81 of the multiple parts.

[0058] From the viewpoint of suitably maintaining the state in which the electrode assembly 20 is sealed by the exterior housing 40, the seal strength of the second sealing portion 92 is preferably 40 N / 15 mm or more, more preferably 50 N / 15 mm or more, even more preferably 60 N / 15 mm or more, even more preferably 70 N / 15 mm or more, and even more preferably 85 N / 15 mm or more. When the seal strength of the second sealing portion 92 is 40 N / 15 mm or more, the state in which the electrode assembly 20 is sealed by the exterior housing 40 is suitably maintained even after the electricity storage device 10 has been used for, for example, several years (less than 10 years). When the seal strength of the second sealing portion 92 is 85 N / 15 mm or more, the state in which the electrode assembly 20 is sealed by the exterior housing 40 is suitably maintained even after the electricity storage device 10 has been used for, for example, 10 years or more. The seal strength of the second sealing portion 92 is preferably 300 N / 15 mm or less. A preferred range for the seal strength of the second sealing portion 92 is 40N / 15mm to 300N / 15mm, 50N / 15mm to 300N / 15mm, 60N / 15mm to 300N / 15mm, 70N / 15mm to 300N / 15mm, or 85N / 15mm to 300N / 15mm.

[0059] In this embodiment, the lid body 60 preferably has a protrusion 86 protruding from the lid seal portion 81 to prevent a gap from forming between the exterior film 50 and the lid body 60. The protrusion 86 may be formed integrally with the covering body 80, or may be formed separately from the covering body 80 and joined to the covering body 80. In this embodiment, the protrusion 86 is formed integrally with the covering body 80. The position at which the protrusion 86 is formed in the lid seal portion 81 can be selected arbitrarily. A gap between the exterior film 50 and the lid body 60 is likely to form, for example, between the base 91X of the first sealing portion 91 and the lid body 60. In particular, when the base 91X of the first sealing portion 91 is located between the boundary 82 and boundary 85 of the lid body 60, the resin filling ability between the base 91X of the first sealing portion 91 and the lid body 60 is likely to decrease. For this reason, the protrusion 86 is preferably formed in the lid seal portion 81 at the location where the base 91X of the first sealing portion 91 is located. In this embodiment, the base 91X of the first sealing portion 91 is located at the boundary 82 of the lid body 60. For this reason, the protrusion 86 is preferably formed at the boundary 82 in the lid seal portion 81. In this embodiment, the first sealing portion 91 is sealed with the protrusion 86 sandwiched between them. Note that the protrusion 86 may be formed on at least one of the first seal surface 81A, the second seal surface 81B, the third seal surface 81C, the fourth seal surface 81D, the boundary 83, the boundary 84, and the boundary 85.

[0060] The shape of the protrusion 86 can be selected arbitrarily. In this embodiment, the shape of the protrusion 86 is plate-like. The thickness of the protrusion 86 can be selected arbitrarily. In this embodiment, the thickness of the protrusion 86 becomes thinner with increasing distance from the boundary 82. In other words, the protrusion 86 has a tapered shape with increasing distance from the boundary 82. The thickness of the protrusion 86 may be constant, or may increase with increasing distance from the boundary 82.

[0061] The direction in which the protrusion 86 extends can be selected arbitrarily. In this embodiment, the protrusion 86 extends along a first direction (in this embodiment, the LR direction). The protrusion 86 may extend along a second direction (in this embodiment, the UD direction). The protrusion 86 may extend in a third direction that intersects with the first direction (in this embodiment, the LR direction) and the second direction (in this embodiment, the UD direction) when the lid 60 is viewed from the front.

[0062] The length of the protrusion 86 can be selected arbitrarily within a range equal to or less than the length of the first sealing portion 91. For example, the length of the protrusion 86 may be substantially equal to the length of the first sealing portion 91, or may be 30% to 50% of the length of the first sealing portion 91.

[0063] <1-2. Method for manufacturing electricity storage devices> 10 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, and a fourth step. The first step to the fourth step are performed, for example, by a manufacturing apparatus for the electricity storage device 10. At least some of the first step to the fourth step may be performed by an operator. Note that the first step to the fourth 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.

[0064] In the first process of step S11, the manufacturing equipment places the lid bodies 60 on both ends of the electrode body 20 and connects the ends 31 of the current collector 30 to the lid bodies 70 of the lid bodies 60. By completing the first process, the lid bodies 60, which function as electrode terminals, and the electrodes of the electrode body 20 are electrically connected.

[0065] The second step of step S12 is performed after the first step. In the second step, the manufacturing apparatus winds the exterior film 50 around the electrode assembly 20 and the lid body 60 while tension is applied to the exterior film 50, while restricting the movement of the electrode assembly 20 and the lid body 60 using a restricting means. The restricting means is, for example, a groove into which the electrode assembly 20 and the lid body 60 are fitted. The restricting means may be a device that applies an external force to the electrode assembly 20 and the lid body 60 to prevent the electrode assembly 20 and the lid body 60 from moving. The restricting means may be a device that applies a force to the electrode assembly 20 and the lid body 60 in a direction opposite to the direction in which the exterior film 50 is pulled. Note that the restricting means may include a roller that runs on the exterior film 50 while the exterior film 50 is being pulled, in order to remove wrinkles in the exterior film 50.

[0066] The third step of step S13 is carried out after the second step. The manufacturing device forms the second sealed portion 92 by heat-sealing the exterior film 50 and the lid 60 together.

[0067] The fourth step of step S14 is performed before or after the third step. In the fourth step, the manufacturing apparatus forms a first sealing 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 while restricting movement of the electrode body 20 and the lid body 60 and applying tension to the exterior film 50 so that the protruding portion 86 of the lid body 60 is sandwiched between the exterior film 50.

[0068] <1-3. Actions and Effects of Electricity Storage Devices> According to the electricity storage device 10, the housing portion 71X is formed in the lid body 70, so that the end portion 31 of the current collector 30 can be suitably restrained.

[0069] [2. Modifications] The above-described embodiments are examples of possible forms of the lid body and the electricity storage device according to the present invention, and are not intended to limit the forms. The lid body and the electricity storage device according to the present invention may take forms different from those exemplified in the embodiments. Examples of such forms include forms in which part of the configuration of the embodiment is replaced, modified, or omitted, or forms in which a new configuration is added to the embodiment. Some examples of modified forms of the embodiments are shown below. Note that the following modified forms can be combined with each other as long as there is no technical contradiction.

[0070] <2-1. First modified example> In the electricity storage device 10 of the above embodiment, the lid 60 does not have to have the protrusion 86. The first modification can also be similarly applied to the following second to eleventh modifications.

[0071] <2-2. Second modified example> In the electricity storage device 10 of the above embodiment, the configuration of the lid main body 70 can be modified. Fig. 11 is a perspective view of the rear side of a lid main body 270 of a second modified example. Fig. 12 is an enlarged view of part X in Fig. 11.

[0072] In the lid body 270 of the second modified example, at least some of the through holes 72Z may be omitted from the covering portion 72. At least a portion of the covering portion 72 may have a roughened surface 73. The roughened surface 73 can be formed, for example, by roughening the surface 72X of the covering portion 72. Specific methods for the roughening treatment include, for example, shot blasting, polishing, anodizing, wet etching, plasma treatment, laser treatment, sandblasting, or roughened plating. To strengthen the bonding strength between the lid body 270 and the covering 80, it is preferable that the entire surface 72X of the covering portion 72 of the lid body 270 be roughened. In other words, it is preferable that the entire surface 72X of the covering portion 72 is a roughened surface 73. As shown in FIG. 12 , minute irregularities are formed on the roughened surface 73. The distance between adjacent peaks of minute irregularities may be approximately 0.01 to 300 μm. When the cover 80 is injection molded onto the lid body 270, the lid body 270 and the cover 80 are more firmly bonded due to the anchor effect. To achieve a stronger anchor effect, the maximum height roughness Rz of the rough surface 73 is preferably in the range of 0.01 μm to 500 μm, and more preferably in the range of 0.5 μm to 200 μm. The maximum height roughness Rz of the rough surface 73 is measured in accordance with JIS B 0601-2001. The maximum height roughness Rz of the rough surface 73 is measured using a laser microscope VK-X3000 equipped with a white light interferometer manufactured by Keyence Corporation.

[0073] In the second modification, the lid body 270 may include at least one of an adhesive film and an adhesive layer to ensure a favorable bond between the lid body 270 and the cover 80. The adhesive film or adhesive layer may be a single layer or a multilayer, and preferably contains at least a resin material having a polar group. The adhesive layer can be formed by dip coating, a dispenser, inkjet printing, spraying, screen printing, or the like.

[0074] In the second modified example, the covering body 80 may be joined to the lid body 270 by insert molding, press molding, induction heating compression bonding, laser heating, or friction stirring. In the second modified example, in order to improve adhesion between the lid body 270 and the covering body 80, at least one of the covering body 80 and the rough surface 73 of the covering portion 72 may be anodized or plated, or a resin reactive coating may be formed. The rough surface 73 preferably has the corrosion-resistant coating described for the barrier layer 52.

[0075] <2-3.Third modified example> FIG. 13 is a perspective view of the front side of the lid main body 370 of the third modified example. The lid main body 370 may have a rectangular container 370X disposed in a space surrounded by the covering portion 72. The container 370X may be formed integrally with the base 71, or may be formed separately from the base 71 and joined to the base 71. A side surface of the container 370X faces a rear surface 72Y of the covering portion 72 with a small gap therebetween. A covering body 80 may be disposed in the gap between the side surface of the container 370X and the rear surface 72Y of the covering portion 72. A container portion 371X may be formed in the container 370X. When the container 370X has the container portion 371X, the lid body 60 is disposed so that the opening of the container portion 371X of the lid main body 370 faces the electrode body 20.

[0076] <2-4. Fourth Modification> 14 is a cross-sectional view of an electricity storage device 10 including a lid main body 470 of a fourth modified example. The covering portion 72 of the lid main body 470 may have recesses 472Z that do not penetrate the covering portion 72 instead of or in addition to the through-holes 72Z. The recesses 472Z may be recessed from the front surface 72X toward the back surface 72Y, or may be recessed from the back surface 72Y toward the front surface 72X. The specifications regarding the number of recesses 472Z formed in the covering portion 72 and the positions at which the recesses 472Z are formed in the covering portion 72 are the same as the specifications regarding the through-holes 72Z. In the fourth modified example, as in the second modified example, a rough surface 73 may be formed on at least a portion of the front surface 72X of the covering portion 72.

[0077] <2-5. Fifth Modification> 15 is a cross-sectional view of an electricity storage device 10 including a lid main body 570 of a fifth modified example. The covering portion 72 of the lid main body 570 may have a protrusion 572Z protruding from the covering portion 72 toward the covering body 80 instead of or in addition to the through-hole 72Z. The protrusion 572Z may protrude from the front surface 72X toward the covering body 80, or may protrude from the back surface 72Y toward the covering body 80. The specifications regarding the number of protrusions 572Z formed on the covering portion 72 and the positions at which the protrusions 572Z are formed on the covering portion 72 are the same as the specifications regarding the through-hole 72Z. In the fifth modified example, as in the second modified example, a rough surface 73 may be formed on at least a portion of the front surface 72X of the covering portion 72.

[0078] <2-6. Sixth Variation> In the electricity storage device 10 of the above embodiment, the cover 80 may be omitted from the lid 60. In the sixth modified example, the surface 72X of the lid main body 70 and the heat-sealable resin layer 53 of the exterior film 50 are joined together. In the sixth modified example, the surface 72X of the lid main body 70 and the heat-sealable resin layer 53 of the exterior film 50 are preferably joined together via an adhesive film that is suitably bonded to metal materials and resin materials. The sixth modified example can also be applied to the other modified examples.

[0079] <2-7. Seventh Variation> In the above-described embodiment, the configuration of the storage portion 71X can be modified as desired as long as it can be connected to the end portion 31 of the current collector 30. FIG. 16 is a cross-sectional view of an electricity storage device 10 according to a seventh modified example. The electricity storage device 10 according to the seventh modified example includes a storage portion 700. The storage portion 700 is, for example, a known clip. The storage portion 700 may be a slide clip. The storage portion 700 includes a base 710 and a clamping portion 720. The base 710 is joined to the first surface 71A of the lid main body 70. The clamping portion 720 is connected to the base 710 and is configured to clamp a portion of the current collector 30 that includes the end portion 31. In the seventh modified example, the current collector 30 and the lid main body 70 can be connected by clamping a portion of the current collector 30 that includes the end portion 31 with the clamping portion 720, thereby facilitating the manufacture of the electricity storage device 10. Furthermore, when the accommodation portion 700 is a slide clip, in the FB direction, the current collector 30 can be inserted into the clamping portion 720 in a direction approaching the base portion 710, but movement in a direction away from the base portion 710 is restricted by the clamping portion 720. Therefore, the state in which the current collector 30 is clamped by the clamping portion 720 is suitably maintained.

[0080] <2-8. Eighth Variation> In the electricity storage device 10 of the above embodiment, the specific method for forming the protrusion 86 of the lid body 60 can be changed as desired. For example, the protrusion 86 may be formed by an adhesive film or the like that is bonded to the lid seal portion 81 of the lid main body 70. In this modification, for example, the protrusion 86 may be formed by bonding a plurality of adhesive films to the lid seal portion 81 in an overlapping manner, or the protrusion 86 may be formed by bonding an adhesive film to the lid seal portion 81 in a flap shape.

[0081] <2-9. 9th 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 like a Gabeltop pouch or a brick pouch.

[0082] <2-10. 10th 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. The portion of the exterior film 50 that protrudes outward beyond the electrode body 20 may be folded like a Gabeltop pouch or a brick pouch.

[0083] <2-11. 11th 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. [Explanation of symbols]

[0084] 10: Energy storage device 20: Electrode body 30: Current collector 32: Edge 40: Exterior body 50: Exterior film 60: Lid 70, 270, 370, 470, 570: Lid body 71X: Storage unit 72: Covering part 72X :Surface 73: Rough surface 80: Covering body

Claims

1. A lid used for an exterior body of an electricity storage device, a lid body including a metal material; The lid body is A base and a frame-shaped covering portion rising from the base portion; a housing portion that houses an end portion of a current collector of the electricity storage device; a bottom portion of the housing portion is located within a space surrounded by the covering portion; The covering portion has a width that allows it to be joined to the exterior film that constitutes the exterior body. Lid body.

2. The housing portion is a recess that does not penetrate the base portion. The lid according to claim 1 .

3. The cover further includes a resin material and covers a portion of the lid body. The lid according to claim 1 or 2.

4. The covering portion has at least one of a through hole, a recess recessed on the side opposite to the covering body, or a protrusion protruding toward the covering body. The lid according to claim 3.

5. At least a portion of the covering portion has a rough surface. The lid according to claim 1 or 2.

6. 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 body joined to the exterior film, The lid body is a lid body including a metal material; The lid body is A base and a frame-shaped covering portion rising from the base portion; a housing portion that houses an end portion of a current collector of the electricity storage device; a bottom portion of the housing portion is located within a space surrounded by the covering portion; The covering portion has a width that allows it to be joined to the exterior film. Energy storage device.

Images