Lid, lid body, power storage device

Abstract

To provide a lid body, a lid main body, and a power storage device that can contribute to suitably sealing an electrode body with an exterior film.SOLUTION: A lid body used for the exterior of a power storage device includes a lid main body containing a metal material and a covering body containing a resin material and covering a portion of the lid main body, the lid main body includes a covering portion covered by the covering body, and the covering portion includes at least one of a through hole, a recessed portion recessed on the side opposite the covering body, or a protrusion protruding toward the covering body.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a lid, a lid main body, 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 and an exterior body that seals the electrode assembly. The exterior body includes an exterior film that encases the electrode assembly and a lid body that is joined to the exterior film. The lid body is made of, for example, a metal material. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-123686 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned electricity storage device, since the exterior film is made of a resin material and the lid is made of a metal material, the bonding strength between the exterior film and the lid may be low, and therefore there is room for improvement in terms of suitably sealing the electrode assembly with the exterior.

[0005] An object of the present invention is to provide an electricity storage device in which an electrode assembly can be suitably sealed with an exterior body, a lid body used in this electricity storage device, and a lid main body constituting this lid body. [Means for solving the problem]

[0006] The 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 a covering body comprising a resin material and covering a portion of the lid main body, wherein the lid main body has a covering portion covered by the covering body, and the covering portion has at least one of a through hole, a recessed portion recessed on the opposite side to the covering body, or a protrusion protruding toward the covering body.

[0007] A lid according to a second aspect of the present invention is the lid according to the first aspect, wherein at least a portion of the covering portion is sandwiched by the covering.

[0008] A lid according to a third aspect of the present invention is the lid according to the first or second aspect, wherein at least a part of the cover portion has a rough surface.

[0009] A lid body according to a fourth 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 a covering body comprising a resin material and covering a portion of the lid main body, wherein the lid main body has a covering portion covered by the covering body, and at least a portion of the covering portion has a rough surface.

[0010] A lid according to a fifth aspect of the present invention is the lid according to the fourth aspect, wherein the maximum height roughness Rz of the rough surface is in the range of 0.01 μm or more and 500 μm or less.

[0011] A lid body according to a sixth aspect of the present invention is a lid body constituting a lid body used in an exterior body of an electricity storage device, the lid body being composed of a metal material and having a covering portion covered by a covering body composed of a resin material, the covering portion having at least one of a through hole, a recessed portion recessed on the side opposite the covering body, or a protrusion protruding toward the covering body.

[0012] A lid body according to a seventh aspect of the present invention is a lid body constituting a lid body used in an exterior body of an electricity storage device, the lid body being composed of a metal material and having a covering portion covered by a covering body composed of a resin material, at least a portion of the covering portion having a rough surface.

[0013] An energy storage device according to an eighth 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, the lid body including a lid main body comprising a metal material and a covering body comprising a resin material that covers a portion of the lid main body, the lid main body having a covering portion covered by the covering body, and the covering portion having at least one of a through hole, a recess that is recessed on the opposite side to the covering body, or a protrusion that protrudes toward the covering body.

[0014] A ninth aspect of the present invention provides an energy storage device comprising 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, the lid body including a lid main body comprising a metal material and a covering body comprising a resin material that covers a portion of the lid main body, the lid main body having a covering portion covered by the covering body, and at least a portion of the covering portion having a rough surface. Effect of the Invention

[0015] The lid body, lid main body, and electricity storage device according to the present invention can contribute to suitably sealing the electrode body with the exterior body. [Brief description of the drawings]

[0016] [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 a second sealing portion of the electricity storage device in FIG. 1A. [Diagram 2] 1B is a cross-sectional view showing a layer structure of an exterior film included in the electricity storage device of FIG. 1A. [Diagram 3]FIG. 1B is a diagram showing the state in which the exterior film of the power storage device of FIG. 1A is unfolded. [Figure 4] 1B is a cross-sectional view taken along line D4-D4 in FIG. 1A. [Diagram 5] FIG. 5 is a side view of the lid body with the exterior film of FIG. 4 omitted. [Figure 6] FIG. 5 is a plan view of the lid body with the exterior film of FIG. 4 omitted. [Figure 7] 5 is a front perspective view of a lid main body of the lid body of FIG. 4. [Figure 8] FIG. 8 is a perspective view of the rear side of the lid body in FIG. 7. [Figure 9] 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 in FIG. 1A. [Figure 11] FIG. 11 is a perspective view of the rear side of a lid body of a second modified example. [Figure 12] An enlarged view of part X in Figure 11. [Figure 13] FIG. 13 is a perspective view of the rear side of a lid body of a third modified example. [Figure 14] FIG. 13 is a cross-sectional view of an electricity accumulation device including a lid body according to a fourth modified example. [Figure 15] FIG. 13 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 PREFERRED EMBODIMENTS

[0017] 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 "not less than" or "not more than." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less.

[0018] [Embodiment] <1-1. Configuration of the power storage device> FIG. 1A is a perspective view that typically illustrates an electricity storage device 10 of an embodiment. FIG. 1B is a diagram that illustrates a method for measuring the seal strength of the second sealing portion 92 of the electricity storage device 10 of FIG. 1. FIG. 2 is a cross-sectional view that illustrates a layer structure of an exterior film 50 that is included in the electricity storage device 10 of FIG. 1A. FIG. 3 is a diagram that illustrates the exterior film 50 that is included in the electricity storage device 10 of FIG. 1A in an unfolded state. FIG. 4 is a cross-sectional view along the line D4-D4 in FIG. 1A. FIG. 5 is a side view of a lid body 60 that is 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 that is 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 along the line D9-D9 in FIG. 1A. 1A, the direction of arrow UD indicates the thickness direction of the power storage device 10, the direction of arrow LR indicates the width direction of the power storage device 10, and the direction of arrow FB indicates the depth direction of the power storage device 10. The directions indicated by the arrows UDLRFB are the same in the subsequent figures.

[0019] The electricity storage device 10 includes an electrode body 20 including a current collector 30, 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, and a separator. In this embodiment, the shape of the electrode body 20 is an approximately rectangular parallelepiped. Note that the term "approximately rectangular parallelepiped" includes, in addition to a complete rectangular parallelepiped, a solid body that can be regarded as a rectangular parallelepiped by modifying the shape of a part of the outer surface, for example. The shape of the electrode body 20 may be, for example, a cylinder or a polygonal prism.

[0020] One end 31 of the current collector 30 (see FIG. 9) is connected to the lid 60.

[0021] The exterior body 40 seals the electrode body 20. The exterior body 40 includes an exterior film 50 and a lid body 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 an opening 40A. The lid body 60 is disposed 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 configured in a cylindrical shape so as to form the opening 40A, and the opening 40A may be closed by the lid body 60.

[0022] For example, there is a method of forming a recess in the exterior film 50 through cold forming to accommodate the electrode body 20. However, it is not necessarily easy to form a deep recess by such a method. If an attempt is made to form a deep recess (for example, a forming depth of 15 mm) by cold forming, pinholes or cracks will occur in the exterior film 50, which is likely to cause a decrease in battery performance. On the other hand, the exterior body 40 seals the electrode body 20 by wrapping the exterior film 50 around the electrode body 20, so that the electrode body 20 can be easily sealed regardless of the thickness of the electrode body 20. In addition, in order to reduce the dead space between the electrode body 20 and the exterior film 50 to improve the volumetric energy density of the power storage device 10, it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20. In addition, in an all-solid-state battery, it is necessary to apply a high pressure uniformly from the outer surface of the battery to exhibit battery performance, so it is necessary to eliminate the space between the electrode body 20 and the exterior film 50, and therefore it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20.

[0023] As shown in FIG. 2, the exterior film 50 is a laminate (laminate film) having, for example, a base layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in this order. The exterior film 50 does not need to include all of these layers, and may not include, for example, the barrier layer 52. That is, the exterior film 50 may be made of a material that is flexible and easy to bend, and may be made of, for example, a resin film. The exterior film 50 is preferably heat-sealable. The innermost layer and the outermost layer of the exterior film 50 may be the heat-sealable resin layer 53. In this case, the exterior film 50 may wrap the electrode body 20 and the lid body 60 by joining the outermost layer and the innermost layer.

[0024] The base layer 51 included in the exterior film 50 is a layer for imparting heat resistance to the exterior film 50 and suppressing the occurrence of pinholes that may occur during processing or distribution. The base layer 51 is configured to include at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer. For example, the base layer 51 includes at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer, so that the barrier layer 52 can be protected during processing of the exterior film 50 and breakage of the exterior film 50 can be suppressed. In addition, 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, in terms 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 base layer 51 may be configured to include both a stretched polyester resin layer and a stretched polyamide resin layer. The thickness of the base layer 51 is, for example, preferably 5 to 300 μm, and more preferably 5 to 150 μm, from the viewpoint of film strength.

[0025] The barrier layer 52 is a layer that at least prevents the intrusion of moisture. 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 foil, vapor deposition film, and resin layer having barrier properties. Examples of the vapor deposition film include metal vapor deposition film, inorganic oxide vapor deposition film, and carbon-containing inorganic oxide vapor deposition film, and examples of the resin layer include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, and ethylene-vinyl alcohol copolymers. Examples of the barrier layer 52 include resin films having at least one of these vapor deposition films and resin layers. The barrier layer 52 may be provided in a plurality of layers. It is preferable that the barrier layer 52 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 material contains at least one of an aluminum alloy foil and a stainless steel foil.

[0026] In the barrier layer 52, the layer made of the above-mentioned metal material may contain recycled metal material. Examples of recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, or steel plate. These recycled materials can be obtained by known methods. The recycled aluminum alloy material can be obtained by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 52 may be made of only recycled materials, or may be made of a mixed material of recycled materials and virgin materials. Note that recycled metal materials refer to metal materials that have been made reusable by collecting, isolating, and refining various products used in the city and waste from the manufacturing process. In addition, virgin metal materials refer to new metal materials refined from natural metal resources (raw materials) and are not recycled materials.

[0027] 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, and from the viewpoint of further improving the formability or conformability, the aluminum alloy foil is preferably an iron-containing aluminum alloy foil. In the iron-containing aluminum alloy foil (100 mass%), the iron content is preferably 0.1 to 9.0 mass%, more preferably 0.5 to 2.0 mass%. By making the iron content 0.1 mass% or more, an exterior film 50 having better formability can be obtained. By making the iron content 9.0 mass% or less, an exterior film 50 having better flexibility can be obtained. In addition, silicon, magnesium, copper, manganese, etc. may be added as necessary. In addition, softening can be performed by annealing treatment, etc. 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.

[0028] Examples of the stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. From the viewpoint of providing an exterior film 50 with excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0029] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, and SUS316L, and among these, SUS304 is particularly preferred.

[0030] In the case of a metal foil, the thickness of the barrier layer 52 should be such that it at least functions as a barrier layer to prevent the intrusion of moisture, 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. Preferable 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 an aluminum alloy foil, the above-mentioned ranges are particularly preferable. 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. Preferable ranges are about 35 to 200 μm, about 35 to 85 μm, about 35 to 75 μm, about 35 to 70 μm, about 45 to 200 μm, about 45 to 85 μm, about 45 to 75 μm, about 45 to 70 μm, about 50 to 200 μm, about 50 to 85 μm, about 50 to 75 μm, about 50 to 70 μm, about 55 to 200 μm, about 55 to 85 μm, about 55 to 75 μm, and about 55 to 70 μm. When the exterior film 50 has high formability, deep drawing becomes easy, which can contribute to increasing the capacity of the electricity storage device. Furthermore, when the capacity of the electricity storage device is increased, the weight of the electricity storage device increases, but the rigidity of the exterior film 50 is increased, which 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.

[0031] In addition, when the barrier layer 52 is an aluminum foil, it is preferable that at least the surface opposite to the base layer 51 is provided with a corrosion-resistant film in order to prevent dissolution and corrosion. The barrier layer 52 may be provided with a corrosion-resistant film on both sides. Here, the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) on the barrier layer 52 by performing, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment such as nickel or chromium, or corrosion prevention treatment by applying a coating agent on the surface of the barrier layer 52. Specifically, the corrosion-resistant film refers to a film that improves the acid resistance of the barrier layer 52 (acid-resistant film), a film that improves the alkali resistance of the barrier layer 52 (alkali-resistant film), etc. The treatment for forming the corrosion-resistant film may be one type, or two or more types may be combined. In addition, not only one layer but also multiple layers may be formed. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by 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. In addition, when the barrier layer 52 has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer 52.

[0032] 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 moisture, and in particular 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.

[0033] The heat-sealable resin layer 53 is bonded to the barrier layer 52, for example, via 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. The thickness of the heat-sealable resin layer 53 is preferably, for example, 20 to 300 μm, and more preferably 40 to 150 μm, in terms of sealability and strength.

[0034] The exterior film 50 preferably has one or more layers having 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 via the base material layer 51, the barrier layer 52, etc.

[0035] The material constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. The material having cushioning properties is, for example, rubber, nonwoven fabric, or foam sheet. The rubber is, for example, natural rubber, fluororubber, or 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 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 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. Among these, the thickness of the buffer layer is most preferably in the range of 1000 μm to 3000 μm.

[0036] When the buffer layer is made of rubber, the lower limit of the thickness of the buffer layer is preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, and more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the thickness of the buffer layer is 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0037] 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 electricity storage device 10 is dropped or by handling during production of the electricity storage device 10.

[0038] 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 and covering a part 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.

[0039] 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 copper plated with nickel. 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.

[0040] 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 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 lid body 70 can contain materials other than metal materials in addition to metal materials.

[0041] When the lid body 70 is made of a metal material, it is preferable that the lid body 70 has the corrosion-resistant coating described in the barrier layer 52. The lid body 60 may have at least one of an adhesive film and an adhesive layer between the lid body 70 and the cover 80 for suitably bonding the two. 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, an inkjet, a spray, or screen printing.

[0042] 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 body 20. The second surface 71B is the surface opposite to 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 body 20 and the lid body 60 to improve the volume density, it is preferable that the base 71 be formed with a housing portion 71X that houses the end 31 of the current collector 30.

[0043] The shape of the storage section 71X can be arbitrarily selected as long as it can store at least the end 31 of the current collector 30. In this embodiment, the storage section 71X is a recess recessed from the first surface 71A toward the second surface 71B. The storage section 71X does not penetrate the lid body 70. The opening of the storage section 71X faces the electrode body 20. The bottom of the storage section 71X protrudes from the second surface 71B toward the outside. The storage section 71X extends in the LR direction. The number of storage sections 71X formed in the base 71 can be arbitrarily selected. In the example shown in FIG. 8, two storage sections 71X are formed in the base 71. The two storage sections 71X are aligned in the UD direction. One or three or more storage sections 71X may be formed in the base 71. The end 31 of the current collector 30 is joined to an arbitrary location inside the storage section 71X by, for example, ultrasonic welding or laser welding. The end 31 of the current collector 30 and the housing section 71X may be joined by screw fixing, press fitting, shrink fitting, crimp welding, pressure welding, brazing, or adhesive. When the end 31 of the current collector 30 and the housing section 71X are joined by adhesive, the end 31 of the current collector 30 and the housing section 71X may have conductivity at least in a portion joined by adhesive and a portion other than the portion joined by adhesive. In this embodiment, the lid body 70 is configured to include a metal material, so that the lid body 70 functions as an electrode terminal. Therefore, the electricity storage device 10 has fewer components than conventional electricity storage devices. Note that the lid body 70 may be joined to an electrode terminal, for example, to the bottom of the housing section 71X.

[0044] The covering portion 72 is covered by the covering body 80. The covering portion 72 is a frame-like portion rising 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 constitutes the upper surface of the lid body 70. The first covering portion 72A extends in a first direction (LR direction in this embodiment) in a front view of the lid body 70. The second covering portion 72B and the third covering portion 72C are connected to the first covering portion 72A and constitute the side surface of the lid body 70. The second covering portion 72B and the third covering portion 72C extend in a second direction (UD direction in this embodiment) intersecting with the first direction in a front view of the lid body 70. In this embodiment, the first direction and the second direction are perpendicular to each other in a front view of the lid body 70. The first direction and the second direction do not have to be perpendicular to each other 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.

[0045] 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 body 80. In this embodiment, the entire back surface 72Y is covered by the covering body 80.

[0046] In order to further increase the bonding strength between the lid body 70 and the covering body 80, it is preferable that a through hole 72Z is ​​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 a rectangle. The shape of the through hole 72Z in a plan view may be a circle, an ellipse, a square, or a polygon. When the front surface 72X and the back surface 72Y of the covering portion 72 are covered by 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. Therefore, the bonding strength between the lid body 70 and the covering body 80 can be further increased. The number of through holes 72Z formed in the covering portion 72 can be selected arbitrarily. In the example shown in Fig. 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 each other. The first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D may not have a through hole 72Z formed in some parts.

[0047] The cover 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 constitutes the upper surface of the lid body 60. The first seal surface 81A extends in a first direction (LR direction in this embodiment) in a front view 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 constitute the side surface of the lid body 60. The second seal surface 81B and the third seal surface 81C extend in a second direction (UD direction in this embodiment) intersecting with the first direction in a front view of the lid body 60. In this embodiment, the first direction and the second direction are perpendicular to each other in a front view 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 seal surface 81D forms the lower surface of the lid 60. The fourth seal surface 81D extends in a first direction (the LR direction in this embodiment) in a front view of the lid 60.

[0048] When the lid body 60 is plate-shaped, it is preferable that the lid body 60 has a certain degree of thickness so that deformation of the exterior body 40 is suppressed even when the power storage device 10 is arranged in a stacked manner. From another viewpoint, 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 degree of thickness so that the lid seal portion 81 of the lid body 60 and the exterior film 50 can be suitably heat-sealed when forming the second sealing portion 92 described later. The minimum value of the 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 value of the 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 value of the thickness of the lid seal portion 81 of the lid body 60 may be 20 mm or more. The preferred ranges of 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 expressed as a plate-like body, the embodiment in which the lid body 60 is composed only of a film defined by the [packaging terminology] standard of the JIS (Japanese Industrial Standards) is not included. The thickness of the lid seal portion 81 of the lid body 60 may be different depending on the part of the lid body 60. When the thickness of the lid seal portion 81 of the lid body 60 varies depending on the part, the thickness of the lid seal portion 81 of the lid body 60 is the thickness of the thickest part.

[0049] The lid seal portion 81 further includes boundaries 82, 83, 84, and 85. The boundary 82 is a boundary between the first seal surface 81A and the second seal surface 81B. The boundary 83 is a boundary between the first seal surface 81A and the third seal surface 81C. The boundary 84 is a boundary between the fourth seal surface 81D and the second seal surface 81B. The boundary 85 is a 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 performing R processing. In this embodiment, the boundaries 82 to 85 are angular.

[0050] 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 content of the resin 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 covering 80 can contain materials other than the resin material in addition to the resin material.

[0051] Specific examples of the resin include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenol resin, and modified products of these resins. The resin material may be a mixture of these resins, a copolymer, or a modified product of the copolymer. Of these, the resin material is preferably a heat-fusible resin such as polyester or polyolefin, and more preferably polyolefin. When the resin material is a resin, the covering 80 may be molded by any molding method.

[0052] The resin material contained in the material constituting the coating 80 is preferably an olefin-based random copolymer, more preferably contains a resin containing a polyolefin skeleton as a main component, more preferably contains polyolefin as a main component, and even more preferably contains 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 further containing 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.

[0053] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyesters. Examples of copolymerized polyesters include copolymerized polyesters in which ethylene terephthalate is the main repeating unit. Specific examples of polyesters include copolymerized 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). Of these, the resin material is preferably polybutylene terephthalate from the viewpoint of increasing heat resistance and pressure resistance.

[0054] 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 it has excellent heat fusion properties and electrolyte resistance.

[0055] The resin as the resin material may contain a filler as necessary. Specific examples of the filler include glass beads, graphite, glass fiber, and carbon fiber. When the resin as the resin material contains the filler, the deformation resistance of the covering 80 against temperature changes can be improved.

[0056] The melt mass flow rate of the resin material contained in the material constituting the coating 80 is preferably within the range of 1 g / 10 min to 100 g / 10 min, and more preferably within the range of 5 g / 10 min to 80 g / 10 min. The melt mass flow rate is measured based on JIS K7210-1:2014.

[0057] In this embodiment, with the exterior film 50 wrapped around the electrode body 20 so as to have an opening 40A, the facing surfaces of the exterior film 50 (heat-fusible resin layers 53) are heat-sealed to form a first sealing portion 91.

[0058] 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 arbitrarily selected. In this embodiment, the root 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 root 91X of the first sealed portion 91 may be located on any surface of the exterior body 40. In this embodiment, the first sealed portion 91 protrudes outward from the electrode body 20 in a plan view. The first sealed portion 91 may be folded, for example, toward the second surface 42 of the exterior body 40, or toward the first surface 41.

[0059] In this embodiment, the second sealed portion 92 is formed by heat-sealing the heat-fusible 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-fusible 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 sealed portion 92. The seal strength of the second sealed portion 92 is the seal strength between the heat-fusible 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 LR (width) direction in FIG. 1A.

[0060] The seal strength of the second sealing portion 92 is measured as follows. First, a cut is made in a portion of the exterior film 50 that constitutes the first surface 41 of the exterior body 40, and three strip-shaped members 41X, 41Y, and 41Z (see the two-dot chain line in FIG. 1B) arranged in the LR direction are formed. The width of the three strip-shaped members 41X, 41Y, and 41Z in the LR 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 LR direction is 45 mm or more. Next, the end of the strip-shaped members 41X, 41Y, and 41Z opposite to the end joined to the lid body 60 is pulled upward in the UD direction (the direction opposite to the first surface 41B) to measure the seal strength of each of the strip-shaped members 41X, 41Y, and 41Z. The distance between the chucks in the UD direction is 10 mm. The seal strength of the strip members 41X, 41Y, and 41Z is the peak value of the seal strength of each. In this embodiment, the seal strength of the second sealing portion 92 is the average value of the seal strength of the strip members 41X, 41Y, and 41Z. When the length of the lid body 60 in the LR direction is less than 45 mm, three strip members of an arbitrary width X mm less than 15 mm are formed, and the seal strength of the three strip members is measured in the same manner as when the length of the lid body 60 in the LR direction is 45 mm or more. The obtained seal strengths are divided by the arbitrary width X mm and multiplied by 15 to convert them into the seal strengths of the three strip members in a width of 15 mm. The seal strength of the second sealing portion 92 is the average value of the seal strengths of the three strip members converted into a width of 15 mm. In addition, when the lid body 60 is divided into multiple parts including long sides and short sides, the seal strength of the second sealing portion 92 is the seal strength of the long side portion of the lid seal portion 81 of the multiple parts.

[0061] From the viewpoint of suitably maintaining the state in which the electrode body 20 is sealed by the exterior body 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, more preferably 60 N / 15 mm or more, more preferably 70 N / 15 mm or more, and 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 body 20 is sealed by the exterior body 40 is suitably maintained even if the power storage device 10 is 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 body 20 is sealed by the exterior body 40 is suitably maintained even if the power storage device 10 is 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 of 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.

[0062] In this embodiment, the lid body 60 preferably has a protruding portion 86 protruding from the lid seal portion 81 so that a gap is unlikely to be formed between the exterior film 50 and the lid body 60. The protruding portion 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 protruding portion 86 is formed integrally with the covering body 80. The position at which the protruding portion 86 is formed in the lid seal portion 81 can be arbitrarily selected. A gap between the exterior film 50 and the lid body 60 is likely to be formed, 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 at the boundary 82 to the boundary 85 of the lid body 60, the resin filling property between the base 91X of the first sealing portion 91 and the lid body 60 is likely to decrease. For this reason, the protruding portion 86 is preferably formed at the location where the base 91X of the first sealing portion 91 is located in the lid seal portion 81. In this embodiment, the root 91X of the first sealing portion 91 is located at the boundary 82 of the lid body 60. For this reason, the protruding portion 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 protruding portion 86 sandwiched between them. Note that the protruding portion 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.

[0063] 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 as it moves away from the boundary 82. In other words, the protrusion 86 has a tapered shape as it moves away from the boundary 82. The thickness of the protrusion 86 may be constant, or may become thicker as it moves away from the boundary 82.

[0064] 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 intersecting 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.

[0065] 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.

[0066] <1-2. Method for manufacturing electricity storage device> 10 is a flowchart showing an example of a method for manufacturing the power storage device 10. The method for manufacturing the power 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 device for the power storage device 10. At least a part of the first step to the fourth step may be performed by an operator. Note that the first step to the fourth step are merely names of the steps in the method for manufacturing the power storage device 10 defined for convenience, and do not necessarily refer to the order of the steps.

[0067] In the first step of step S11, the manufacturing equipment places the lid body 60 on both ends of the electrode body 20 and connects the ends 31 of the current collector 30 to the lid body 70 of the lid body 60. By completing the first step, the lid body 60, which functions as an electrode terminal, and the electrodes of the electrode body 20 are electrically connected.

[0068] The second step of step S12 is performed after the first step. In the second step, the manufacturing device winds the exterior film 50 around the electrode body 20 and the lid body 60 while tension is applied to the exterior film 50, while restricting the movement of the electrode body 20 and the lid body 60 by the restricting means. The restricting means is, for example, a groove into which the electrode body 20 and the lid body 60 are fitted. The restricting means may be a device that applies an external force to the electrode body 20 and the lid body 60 so that the electrode body 20 and the lid body 60 do not move. The restricting means may be a device that applies a force to the electrode body 20 and the lid body 60 in the opposite direction to the direction in which the exterior film 50 is pulled. 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.

[0069] The third process of step S13 is carried out after the second process. The manufacturing apparatus forms the second sealed portion 92 by heat-sealing the exterior film 50 and the lid body 60 together.

[0070] The fourth step of step S14 is performed before or after the third step. In the fourth step, the manufacturing device forms a first sealing portion 91 by heat-sealing the heat-sealable resin layer 53 of the portion including the first edge 50A of the exterior film 50 and the heat-sealable resin layer 53 of the portion including the second edge 50B while restricting the movement of the electrode body 20 and the cover body 60 and applying tension to the exterior film 50 so that the protruding portion 86 of the cover body 60 is sandwiched by the exterior film 50.

[0071] <1-3. Actions and Effects of Electricity Storage Devices> In the electricity storage device 10, the lid body 60 is covered by the covering body 80, which is made of a lid main body 70 containing a resin material, and therefore the bonding strength between the covering body 80 and the exterior film 50 is high. Therefore, the electrode body 20 can be suitably sealed by the exterior body 40.

[0072] [2. Modifications] The above-mentioned embodiment is an example of the form that the lid body, the lid main body, and the electricity storage device according to the present invention can take, and is not intended to limit the form. The lid body, the lid main body, and the electricity storage device according to the present invention can take a form different from the form exemplified in the embodiment. One example is a form in which a part of the configuration of the embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to the embodiment. Some examples of modified embodiments are shown below. Note that the following modified embodiments can be combined with each other as long as there is no technical contradiction.

[0073] <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.

[0074] <2-2. Second modified example> In the electricity storage device 10 of the above embodiment, the configuration of the lid body 70 can be modified. Fig. 11 is a perspective view of the rear side of a lid body 270 of a second modified example. Fig. 12 is an enlarged view of a portion X in Fig. 11.

[0075] In the lid body 270 of the second modification, at least a part of the through-holes 72Z may be omitted from the covering portion 72. At least a part of the covering portion 72 may have a rough surface 73. The rough surface 73 can be formed, for example, by performing a roughening process on the surface 72X of the covering portion 72. Specific methods of the roughening process include, for example, shot blasting, polishing, anodizing, wet etching, plasma processing, laser processing, sandblasting, or roughening plating. In order to strengthen the bonding strength between the lid body 270 and the covering body 80, it is preferable that the entire surface 72X of the covering portion 72 of the lid body 270 is roughened. In other words, it is preferable that the entire surface 72X of the covering portion 72 is a rough surface 73. As shown in FIG. 12, minute irregularities are formed on the rough surface 73. The distance between the peaks of adjacent minute irregularities may be about 0.01 to 300 μm. When the cover 80 is injection molded onto the lid body 270, the cover 80 and the lid body 270 are more firmly bonded to each other due to the anchor effect. In order to obtain a higher anchor effect, the maximum height roughness Rz of the rough surface 73 is preferably within the range of 0.01 μm to 500 μm, and more preferably within the range of 0.5 μm to 200 μm. The maximum height roughness Rz of the rough surface 73 is measured based on JIS B 0601-2001. The maximum height roughness Rz of the rough surface 73 is measured using a laser microscope equipped with a white light interferometer VK-X3000 manufactured by Keyence Corporation.

[0076] In the second modification, from the viewpoint of suitably bonding the lid body 270 and the cover 80, the lid body 270 may include at least one of an adhesive film and an adhesive layer. 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, an inkjet, a spray, or screen printing.

[0077] In the second modification, 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 modification, from the viewpoint of increasing the 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.

[0078] <2-3.Third modified example> FIG. 13 is a perspective view of the front side of the lid body 370 of the third modified example. The lid 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. The side surface of the container 370X faces the back surface 72Y of the covering portion 72 with a small gap therebetween. The covering body 80 may be disposed in the gap between the side surface of the container 370X and the back surface 72Y of the covering portion 72. The container 370X may have a container portion 371X formed therein. When the container 370X has the container portion 371X formed therein, the lid body 60 is disposed so that the opening of the container portion 371X of the lid body 370 faces the electrode body 20.

[0079] <2-4. Fourth modified example> FIG. 14 is a cross-sectional view of an electricity storage device 10 including a lid body 470 of a fourth modified example. The covering portion 72 of the lid body 470 may have a recess 472Z that does not penetrate the covering portion 72 instead of or in addition to the through hole 72Z. The recess 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 number of recesses 472Z formed in the covering portion 72 and the specifications regarding the positions at which the recesses 472Z are formed in the covering portion 72 are the same as the specifications regarding the through hole 72Z. In the fourth modified example, as in the second modified example, a rough surface 73 may be formed on at least a part of the front surface 72X of the covering portion 72.

[0080] <2-5. Fifth Modification> FIG. 15 is a cross-sectional view of an electricity storage device 10 including a lid body 570 of a fifth modified example. The covering portion 72 of the lid body 570 may have a convex portion 572Z protruding from the covering portion 72 toward the covering body 80 instead of or in addition to the through hole 72Z. The convex portion 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 number of the convex portions 572Z formed in the covering portion 72 and the specifications regarding the positions at which the convex portions 572Z are formed in the covering portion 72 are the same as the specifications regarding the through hole 72Z. In the fifth modified example, a rough surface 73 may be formed on at least a part of the front surface 72X of the covering portion 72, as in the second modified example.

[0081] <2-6. Sixth Modification> In the electricity storage device 10 of the above embodiment, the storage portion 71X may be omitted from the lid body 70. In the sixth modified example, the end portion 31 of the current collector 30 may be joined to the first surface 71A of the base portion 71 of the lid body 70, for example.

[0082] <2-7. Seventh Variation> In the above embodiment, the configuration of the storage section 71X can be changed as desired as long as it can be connected to the end 31 of the current collector 30. FIG. 16 is a cross-sectional view of the electricity storage device 10 of the seventh modified example. The electricity storage device 10 of the seventh modified example includes a storage section 700. The storage section 700 is, for example, a known clip. The storage section 700 may be a slide clip. The storage section 700 includes a base 710 and a clamping section 720. The base 710 is joined to the first surface 71A of the lid body 70. The clamping section 720 is connected to the base 710 and is configured to be able to clamp a portion including the end 31 of the current collector 30. In the seventh modified example, the current collector 30 and the lid body 70 can be connected by clamping a portion including the end 31 of the current collector 30 with the clamping section 720, so that the electricity storage device 10 can be easily manufactured. 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, while 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.

[0083] <2-8. Eighth Modification> In the electricity storage device 10 of the above embodiment, the specific method of 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.

[0084] <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.

[0085] <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 a portion of the exterior body 40 where the lid body 60 is omitted, the electrode body 20 is sealed by closing a 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.

[0086] <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]

[0087] 10: Energy storage device 20: Electrode body 40: Exterior body 50: Exterior film 60: Lid 70, 270, 370, 470, 570: Lid body 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; a cover that includes a resin material and covers a portion of the lid body, The covering body has a lid seal portion that is joined to an exterior film that is an element that constitutes the exterior body, The lid body is a covering portion covered by the covering body; a portion configured to be directly connected to the current collector; At least a portion of the covering portion has a rough surface. Lid body.

2. The lid body has a base as a part configured to be directly connected to the current collector. The lid according to claim 1 .

3. The lid body has a housing portion that houses the current collector. The lid according to claim 1 or 2.

4. The maximum height roughness Rz of the rough surface is in the range of 0.01 μm to 500 μm. The lid according to claim 1 or 2.

5. The covering portion is a frame-like portion rising from the base portion. The lid according to claim 2.

6. The base is plate-shaped. The lid according to claim 2.

7. The lid seal portion is a plurality of sealing surfaces joined to the exterior film; and a boundary of the plurality of sealing surfaces; At least one of the boundaries is rounded. The lid according to claim 1 or 2.

8. The material constituting the covering body includes at least one of polyester and polyolefin. The lid according to claim 1 or 2.

9. A lid main body constituting a lid body used for an exterior body of an electricity storage device, The lid body is It is composed of a metal material, a covering portion that is covered by a covering body that contains a resin material; a portion configured to be directly connected to the current collector; The covering body has a lid seal portion that is joined to an exterior film that is an element that constitutes the exterior body, At least a portion of the covering portion has a rough surface. Lid body.

10. An electrode assembly including a current collector; 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; a cover that includes a resin material and covers a portion of the lid body, the covering body has a lid seal portion joined to the exterior film, The lid body is a covering portion covered by the covering body; a portion configured to be directly connected to the current collector; At least a portion of the covering portion has a rough surface. Energy storage device.

Images