Lid, lid body, energy 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 body, a lid main body, and a power storage device.

Background Art

[0002] Patent Document 1 discloses an example of a power storage device. This power storage device includes an electrode body and an exterior body that seals the electrode body. The exterior body includes an exterior film that wraps the electrode body 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

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above power storage device, since the exterior film is composed of a resin material and the lid body is composed of a metal material, there is a possibility that the bonding strength between the exterior film and the lid body is low. Therefore, there is room for improvement in properly sealing the electrode body with the exterior body.

[0005] An object of the present invention is to provide a power storage device that can properly seal an electrode body with an exterior body, a lid body used for this power storage device, and a lid main body that constitutes this lid body.

Means for Solving the Problems

[0006] A lid according to a first aspect of the present invention is a lid used for the exterior of an energy storage device, comprising a lid body made of a metal material and a covering made of a resin material that covers a part of the lid body, 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 recess that is recessed on the opposite side of the covering portion, or a convex portion that protrudes toward the covering portion.

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

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

[0009] A lid according to a fourth aspect of the present invention is a lid used for the exterior of an energy storage device, comprising a lid body made of a metal material and a covering made of a resin material that covers a part of the lid body, wherein the lid body has a covering portion covered by the covering portion, and at least a part of the covering portion has a rough surface.

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

[0011] A lid body according to a sixth aspect of the present invention is a lid body that constitutes a lid used for the exterior of an energy storage device, wherein the lid body is made of a metal material and has a covering portion that is covered by a covering made of a resin material, and the covering portion has at least one of a through hole, a recess that is recessed on the opposite side of the covering, or a convex portion that protrudes toward the covering.

[0012] A lid body according to the seventh aspect of the present invention is a lid body that constitutes a lid used for the exterior of an energy storage device, wherein the lid body is made up of a metal material and has a covering portion that is covered by a covering made of a resin material, and at least a part of the covering portion has a rough surface.

[0013] An energy storage device according to the eighth aspect of the present invention comprises an electrode body and an outer casing that seals the electrode body, wherein the outer casing includes an outer film that encloses the electrode body and a lid that is joined to the outer film, wherein the lid includes a lid body made of a metal material and a covering made of a resin material that covers a part of the lid body, 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 recess that is recessed on the opposite side of the covering portion, or a convex portion that protrudes toward the covering portion.

[0014] A ninth aspect of the present invention relates to an energy storage device comprising an electrode body and an outer casing that seals the electrode body, wherein the outer casing includes an outer film that encloses the electrode body and a lid that is joined to the outer film, and the lid includes a lid body made of a metal material and a covering made of a resin material that covers a part of the lid body, wherein the lid body has a covering portion that is covered by the covering portion, and at least a part of the covering portion has a rough surface. [Effects of the Invention]

[0015] The lid, lid body, and energy storage device according to the present invention contribute to the ability to suitably seal the electrode body with the outer casing. [Brief explanation of the drawing]

[0016] [Figure 1A] A perspective view of the energy storage device according to the embodiment. [Figure 1B] Figure 1A shows a diagram illustrating the method for measuring the seal strength of the second sealing portion of the energy storage device. [Figure 2] A cross-sectional view showing the layer structure of the outer film of the energy storage device in Figure 1A. [Figure 3]View of the exterior film provided in the power storage device of FIG. 1A in an unfolded state. [Figure 4] Cross-sectional view taken along line D4-D4 of FIG. 1A. [Figure 5] Side view of the lid body with the exterior film of FIG. 4 omitted. [Figure 6] Plan view of the lid body with the exterior film of FIG. 4 omitted. [Figure 7] Perspective view of the front side of the lid body of the lid of FIG. 4. [Figure 8] Perspective view of the back side of the lid body of FIG. 7. [Figure 9] Cross-sectional view taken along line D9-D9 of FIG. 1A. [Figure 10] Flowchart showing an example of the manufacturing process of the power storage device of FIG. 1A. [Figure 11] Perspective view of the back side of the lid body of the second modification example. [Figure 12] Enlarged view of the X portion of FIG. 11. [Figure 13] Perspective view of the back side of the lid body of the third modification example. [Figure 14] Cross-sectional view of the power storage device including the lid body of the fourth modification example. [Figure 15] Cross-sectional view of the power storage device including the lid body of the fifth modification example. [Figure 16] Cross-sectional view of the power storage device of the seventh modification example.

Mode for Carrying Out the Invention

[0017] Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the drawings. In this specification, the numerical range indicated by "~" means "or more" and "or less". For example, the notation 2~15 mm means 2 mm or more and 15 mm or less.

[0018] [Embodiment] <1-1. Configuration of the power storage device> Figure 1A is a schematic perspective view of the energy storage device 10 of the embodiment. Figure 1B is a diagram showing a method for measuring the seal strength of the second sealing portion 92 of the energy storage device 10 of Figure 1. Figure 2 is a cross-sectional view showing the layer structure of the outer film 50 provided on the energy storage device 10 of Figure 1A. Figure 3 is a view of the outer film 50 provided on the energy storage device 10 of Figure 1A in an unfolded state. Figure 4 is a cross-sectional view along the line D4-D4 in Figure 1A. Figure 5 is a side view of the lid 60 provided on the energy storage device 10 of Figure 1A. Figure 6 is a top view of the lid 60 of Figure 5. Figure 7 is a front perspective view of the lid body 70 provided on the lid 60 of Figure 4. Figure 8 is a rear perspective view of the lid body 70 of Figure 7. Figure 9 is a cross-sectional view along the line D9-D9 in Figure 1A. In Figure 1A, the arrow UD indicates the thickness direction of the energy storage device 10, the arrow LR indicates the width direction of the energy storage device 10, and the arrow FB indicates the depth direction of the energy storage device 10. The directions indicated by arrows UDLRFB are the same in all subsequent figures.

[0019] The energy storage device 10 comprises an electrode body 20 including a current collector 30 and an outer casing 40. The electrode body 20 includes electrodes (positive and negative electrodes) that constitute an energy storage component such as a lithium-ion battery, capacitor, all-solid-state battery, semi-solid-state battery, pseudo-solid-state 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, polyvalent cation battery, or capacitor, as well as a separator. In this embodiment, the shape of the electrode body 20 is substantially rectangular parallelepiped. Note that "substantially rectangular parallelepiped" includes not only a perfect rectangular parallelepiped but also a solid that can be considered a rectangular parallelepiped by modifying the shape of a part of its outer surface, for example. The shape of the electrode body 20 may be, for example, a cylinder or a polygonal prism.

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

[0021] The outer casing 40 seals the electrode body 20. The outer casing 40 comprises an outer film 50 and a lid 60. The outer film 50 wraps around the electrode body 20 so as to have an opening 40A. In this embodiment, the outer film 50 is wrapped around the electrode body 20 so as to have an opening 40A. The lid 60 is positioned to the side of the electrode body 20 so as to close the opening 40A. Alternatively, the electrode body 20 may be housed inside the outer film 50, which is configured in a cylindrical shape so as to form the opening 40A, and the opening 40A may be closed by the lid 60.

[0022] For example, one method involves forming a recess in the outer film 50 to accommodate the electrode body 20 through cold forming. However, forming a deep recess by such a method is not always easy. If one attempts to form a deep recess (for example, a forming depth of 15 mm) by cold forming, pinholes or cracks may occur in the outer film 50, which is likely to lead to a decrease in battery performance. On the other hand, the outer body 40 seals the electrode body 20 by wrapping the outer film 50 around the electrode body 20, so the electrode body 20 can be easily sealed regardless of its thickness. Furthermore, in order to reduce the dead space between the electrode body 20 and the outer film 50 in order to improve the volumetric energy density of the energy storage device 10, it is preferable that the outer film 50 is wrapped so as to be in contact with the outer surface of the electrode body 20. In addition, in all-solid-state batteries, it is necessary to eliminate the space between the electrode body 20 and the outer film 50 from the viewpoint that high pressure must be applied uniformly from the outside of the battery in order to achieve battery performance, so it is preferable that the outer film 50 is wrapped so as to be in contact with the outer surface of the electrode body 20.

[0023] As shown in Figure 2, the outer film 50 is a laminate (laminate film) having, for example, a base layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in that order. Note that the outer film 50 does not necessarily need to include all of these layers; for example, the barrier layer 52 may be omitted. That is, the outer film 50 only needs to be made of a flexible and easily bendable material, such as a resin film. It is preferable that the outer film 50 is heat-sealable. The innermost and outermost layers of the outer film 50 may be the heat-sealable resin layer 53. In this case, the outer film 50 may enclose the electrode body 20 and the lid 60 by joining the outermost and innermost layers.

[0024] The base layer 51 included in the outer film 50 is a layer that imparts heat resistance to the outer film 50 and suppresses the occurrence of pinholes that may occur during processing or distribution. The base layer 51 is composed of, for example, at least one stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one stretched polyester resin layer and a stretched polyamide resin layer in the base layer 51, the barrier layer 52 can be protected during processing of the outer film 50, and the breakage of the outer film 50 can be suppressed. Furthermore, from the viewpoint of increasing the tensile elongation of the outer film 50, the stretched polyester resin layer is preferably a biaxially oriented polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially oriented polyamide resin layer. Moreover, from the viewpoint of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially oriented polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially oriented nylon (ONy) film. The base 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.

[0025] The barrier layer 52 is a layer that at least prevents the penetration of moisture. The barrier layer 52 is joined to the substrate layer 51, for example, via an adhesive layer 54. Examples of barrier layers 52 include metal foil, vapor-deposited film, and resin layer. Examples of vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Examples of resin layers include fluorine-containing resins such as polymers mainly composed of polyvinylidene chloride, chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, as well as ethylene vinyl alcohol copolymers. In addition, a resin film having at least one of these vapor-deposited films and resin layers can also be provided as the barrier layer 52. Multiple layers of the barrier layer 52 may be provided. Preferably, the barrier layer 52 includes a layer made of a metal material. Examples of metal materials constituting the barrier layer 52 include aluminum alloys, stainless steel, titanium steel, and steel sheets. When used as a metal foil, it is preferable to include at least one of aluminum alloy foil and stainless steel foil.

[0026] In the barrier layer 52, the layer composed of the aforementioned metal material may include recycled metal material. Examples of recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, or steel sheet. These recycled materials can each be obtained by known methods. Recycled aluminum alloy can be obtained, for example, by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 52 may be composed solely of recycled material, or it may be composed of a mixture of recycled material and virgin material. Recycled metal material refers to metal material that has been recovered, isolated, and purified from various products used in the market or waste generated from manufacturing processes to make it reusable. Virgin metal material refers to new metal material refined from natural metal resources (raw materials) and is not recycled material.

[0027] From the viewpoint of improving the formability or conformability of the outer film 50, the aluminum alloy foil is more preferably a soft aluminum alloy foil composed of, for example, an annealed aluminum alloy, and from the viewpoint of further improving formability or conformability, it is more preferably an aluminum alloy foil containing iron. In an iron-containing aluminum alloy foil (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, and more preferably 0.5 to 2.0% by mass. By having an iron content of 0.1% by mass or more, an outer film 50 with better formability can be obtained. By having an iron content of 9.0% by mass or less, an outer film 50 with better flexibility can be obtained. Silicon, magnesium, copper, manganese, etc. may also be added as needed. Softening can be achieved by annealing treatment, etc. From the viewpoint of improving the mechanical strength of the outer film 50, the aluminum alloy foil is more preferably a hard aluminum alloy foil composed of, for example, a work-hardened aluminum alloy.

[0028] Furthermore, examples of stainless steel foils include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation-hardening stainless steel foils. Moreover, from the viewpoint of providing an outer film 50 with excellent formability, it is preferable that the stainless steel foil be made of austenitic stainless steel.

[0029] Specific examples of austenitic stainless steels that make up stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred among these.

[0030] In the case of metal foil, the thickness of the barrier layer 52 should at least function as a barrier layer that prevents moisture from penetrating, and can 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. Also, the thickness of the barrier layer 52 is preferably about 9.0 μm or more, even more preferably about 20 μm or more, and more preferably about 25 μm or more. Furthermore, preferred thickness ranges for the barrier layer 52 include approximately 9.0-85 μm, 9.0-50 μm, 9.0-40 μm, 9.0-35 μm, 20-85 μm, 20-50 μm, 20-40 μm, 20-35 μm, 25-85 μm, 25-50 μm, 25-40 μm, and 25-35 μm. When the barrier layer 52 is made of aluminum alloy foil, the above ranges are particularly preferred. Furthermore, from the viewpoint of providing the outer film 50 with high moldability and high rigidity, the thickness of the barrier layer 52 is preferably about 35 μm or more, more preferably about 45 μm or more, even more preferably about 50 μm or more, even more preferably about 55 μm or more, and also preferably about 200 μm or less, more preferably about 85 μm or less, even more preferably about 75 μm or less, even more preferably about 70 μm or less, and preferably The suitable ranges are approximately 35-200 μm, 35-85 μm, 35-75 μm, 35-70 μm, 45-200 μm, 45-85 μm, 45-75 μm, 45-70 μm, 50-200 μm, 50-85 μm, 50-75 μm, 50-70 μm, 55-200 μm, 55-85 μm, 55-75 μm, and 55-70 μm. The high moldability of the outer film 50 facilitates deep drawing, which can contribute to increasing the capacity of the energy storage device. Furthermore, while increasing the capacity of the energy storage device increases its weight, the increased rigidity of the outer film 50 contributes to the high sealing performance of the energy storage device.Furthermore, in particular when the barrier layer 52 is composed of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and especially preferably about 25 μm or less. Also, the thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Furthermore, preferred ranges for the thickness of the stainless steel foil include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0031] Furthermore, if the barrier layer 52 is aluminum foil, it is preferable to provide a corrosion-resistant coating on at least the side opposite to the base layer 51 to prevent dissolution and corrosion. The barrier layer 52 may have a corrosion-resistant coating on both sides. Here, a corrosion-resistant coating refers to a thin film that provides corrosion resistance (e.g., acid resistance, alkali resistance, etc.) to the barrier layer 52 by performing corrosion prevention treatments on the surface of the barrier layer 52, such as hot water modification treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment with nickel or chromium, or coating agent application. Specifically, a corrosion-resistant coating means a coating that improves the acid resistance of the barrier layer 52 (acid-resistant coating), a coating that improves the alkali resistance of the barrier layer 52 (alkali-resistant coating), etc. One type of treatment may be performed to form the corrosion-resistant coating, or two or more types may be combined. In addition, it is possible to have multiple layers instead of just one layer. Furthermore, among these treatments, hydrothermal modification and anodic oxidation are processes that dissolve the surface of the metal foil with a treatment agent to form a metal compound with excellent corrosion resistance. These treatments may also be included in the definition of chemical conversion treatment. Additionally, if the barrier layer 52 has a corrosion-resistant coating, the barrier layer 52 includes the corrosion-resistant coating.

[0032] The corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 during the molding of the outer film 50, prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride generated by the reaction of electrolyte and water, and in particular prevents the dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52 when the barrier layer 52 is aluminum alloy foil, and improves the adhesion (wettability) of the surface of the barrier layer 52, thereby preventing delamination between the base layer 51 and the barrier layer 52 during heat sealing and during molding.

[0033] The heat-sealable resin layer 53 is joined to the barrier layer 52, for example, via an adhesive layer 55. The heat-sealable resin layer 53 included in the outer film 50 is a layer that imparts heat-seal sealing properties to the outer film 50. Examples of the heat-sealable resin layer 53 include polyester resins such as polyethylene terephthalate resin and polybutylene terephthalate resin, polyolefin resins such as polyethylene resin and polypropylene resin, or 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, from the viewpoint of sealing properties and strength.

[0034] The outer film 50 preferably has one or more layers having a buffering function (hereinafter referred to as "buffering layers") outside the heat-sealable resin layer 53, and more preferably outside the barrier layer 52. The buffering layers may be laminated on the outside of the base layer 51, or the base layer 51 may also have the function of a buffering layer. If the outer film 50 has multiple buffering layers, the multiple buffering layers may be adjacent to each other, or they may be laminated via the base layer 51 or the barrier layer 52, etc.

[0035] The materials constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. Examples of cushioning materials include rubber, nonwoven fabric, or foamed sheet. Examples of rubber include natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably around 20 to 90. The materials constituting the nonwoven fabric are preferably materials with excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the buffer layer thickness is preferably 100 μm, more preferably 200 μm, and still more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the buffer layer thickness is preferably 5000 μm, and still more preferably 3000 μm. The preferred thickness ranges for the buffer layer are 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm. Among these, the most preferred thickness range for the buffer layer is 1000 μm to 3000 μm.

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

[0037] If the outer film 50 has a buffer layer, the buffer layer functions as a cushion, thus preventing damage to the outer film 50 from impact when the energy storage device 10 is dropped or from handling during the manufacturing of the energy storage device 10.

[0038] As shown in Figures 5 and 6, the lid 60 is, for example, a rectangular parallelepiped in shape overall. The lid 60 has a lid body 70 made of a metal material and a cover 80 made of a resin material that covers a part of the lid body 70. The lid 60 can be manufactured, for example, by injection molding the cover 80 onto the lid body 70.

[0039] The metal material constituting the lid body 70 can be arbitrarily selected. Examples of metal materials constituting the lid body 70 include aluminum, aluminum alloy, nickel, copper, or copper alloy. For example, if 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 with nickel plating. The material constituting the lid body 70 may include recycled metal materials. The lid body 70 has a base portion 71 and a covering portion 72.

[0040] The lid body 70 is made of a metallic material. Here, "made of a metallic material" means that when the total mass of the materials constituting the lid body 70 is considered to be 100% by mass, the metallic material content is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In other words, the materials constituting the lid body 70 may contain materials other than metallic materials in addition to metallic materials.

[0041] If the lid body 70 is made of a metal material, it is preferable that the lid body 70 has a corrosion-resistant coating as described in the barrier layer 52. The lid 60 may include at least one of an adhesive film and an adhesive layer between the lid body 70 and the covering 80 to suitably bond them together. The adhesive film or adhesive layer may be a single layer or a multilayer, and preferably contains at least a resin material having polar groups. The adhesive layer can be formed by dip coating, dispensing, inkjet, spraying, or screen printing.

[0042] The base portion 71 shown in Figures 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 portion 31 of the current collector 30 (see Figure 9) and from the viewpoint of shortening the distance between the electrode body 20 and the cover 60 to improve volume density, it is preferable that the base portion 71 has a housing portion 71X that accommodates the end portion 31 of the current collector 30.

[0043] The shape of the housing portion 71X can be arbitrarily selected as long as it can accommodate at least the end portion 31 of the current collector 30. In this embodiment, the housing portion 71X is a recess that curves inward from the first surface 71A toward the second surface 71B. The housing portion 71X does not penetrate the lid body 70. The opening of the housing portion 71X faces the electrode body 20. The bottom of the housing portion 71X protrudes outward from the second surface 71B. The housing portion 71X extends in the LR direction. The number of housing portions 71X formed on the base portion 71 can be arbitrarily selected. In the example shown in Figure 8, two housing portions 71X are formed on the base portion 71. The two housing portions 71X are aligned in the UD direction. One or more housing portions 71X may be formed on the base portion 71. The end portion 31 of the current collector 30 is joined to any point inside the housing portion 71X by, for example, ultrasonic welding or laser welding. The end portion 31 of the current collector 30 and the housing portion 71X may be joined by screw fixing, press fitting, shrink fitting, crimp welding, pressure welding, brazing, or adhesive. When the end portion 31 of the current collector 30 and the housing portion 71X are joined by adhesive, it is sufficient that at least one of the parts of the end portion 31 of the current collector 30 and the housing portion 71X that are joined by adhesive and the parts that are not joined by adhesive are conductive. In this embodiment, since the lid body 70 is made up of a metal material, the lid body 70 functions as an electrode terminal. For this reason, the energy storage device 10 has fewer components than conventional energy storage devices. Note that the lid body 70 may have electrode terminals joined to, for example, the bottom of the housing portion 71X.

[0044] The covering portion 72 is covered by the covering body 80. The covering portion 72 is frame-shaped, 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. In a front view of the lid body 70, the first covering portion 72A extends in a first direction (in this embodiment, the LR direction). 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. In a front view of the lid 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 the first direction. In this embodiment, in a front view of the lid body 70, the first direction and the second direction are orthogonal. The first direction and the second direction do not have to be orthogonal in a front view of the lid body 70. The fourth covering portion 72D constitutes the lower surface of the lid body 70. The fourth covering portion 72D extends in the first direction (in this embodiment, the L-R direction) in a front view of the lid body 70.

[0045] At least a portion of the surface 72X of the covering portion 72 is covered by the covering body 80. In this embodiment, the entire surface 72X of the covering portion 72 is covered by the covering body 80. 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 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] To further increase the bonding strength between the lid body 70 and the covering 80, it is preferable that through holes 72Z are formed in the covering portion 72. The shape of the through holes 72Z in plan view can be arbitrarily selected. In this embodiment, the shape of the through holes 72Z in plan view is rectangular. The shape of the through holes 72Z in plan view may be a circle, an ellipse, a square, or a polygon. When the surface 72X and back surface 72Y of the covering portion 72 are covered by the covering 80, the covering 80 covering the surface 72X of the covering portion 72 and the covering 80 covering the back surface 72Y of the covering portion 72 are connected via the covering 80 located within the through holes 72Z. This further increases the bonding strength between the lid body 70 and the covering 80. The number of through holes 72Z formed in the covering portion 72 can be arbitrarily selected. In the example shown in Figure 7, five through-holes 72Z are formed in the first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D, respectively. The first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D may each have 1 to 4, or 6 or more, through-holes 72Z. The number 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 differ from one another. Through-holes 72Z may not be formed in parts of the first covering portion 72A, the second covering portion 72B, the third covering portion 72C, and the fourth covering portion 72D.

[0047] The covering 80 shown in Figure 4 has a lid sealing portion 81. The lid sealing portion 81 is heat-sealed to the heat-sealable resin layer 53 of the outer film 50. The lid sealing portion 81 includes a first sealing surface 81A, a second sealing surface 81B, a third sealing surface 81C, and a fourth sealing surface 81D. The first sealing surface 81A constitutes the upper surface of the lid 60. In a front view of the lid 60, the first sealing surface 81A extends in a first direction (in this embodiment, the LR direction). The second sealing surface 81B and the third sealing surface 81C connect to the first sealing surface 81A and constitute the side surface of the lid 60. In a front view of the lid 60, the second sealing surface 81B and the third sealing surface 81C extend in a second direction (in this embodiment, the UD direction) that intersects the first direction. In this embodiment, in a front view of the lid 60, the first direction and the second direction are orthogonal. The first and second directions do not have to be orthogonal in a front view of the lid 60. The fourth sealing surface 81D constitutes the lower surface of the lid 60. In a front view of the lid 60, the fourth sealing surface 81D extends in the first direction (in this embodiment, the LR direction).

[0048] If the lid 60 is plate-shaped, it is preferable that the lid 60 has a certain thickness so as to prevent deformation of the outer casing 40 even when the energy storage devices 10 are stacked on top of each other. From another viewpoint, if the lid 60 is plate-shaped, it is preferable that the lid seal portion 81 of the lid 60 has a certain thickness so as to allow for suitable heat sealing of the lid seal portion 81 of the lid 60 and the outer casing film 50 when forming the second sealing portion 92 described later. The minimum thickness of the lid seal portion 81 of the lid 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 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 60 may be 20 mm or more. The preferred thickness ranges for the lid seal portion 81 of the lid 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 60 is described as being plate-shaped, it does not include the case where the lid 60 is composed solely of film as defined by the JIS (Japanese Industrial Standards) [Packaging Terminology] standard. The thickness of the lid seal portion 81 of the lid 60 may vary depending on the part of the lid 60. If the thickness of the lid seal portion 81 of the lid 60 varies depending on the part, the thickness of the lid seal portion 81 of the lid 60 is the thickness of the thickest part.

[0049] The lid seal portion 81 further includes boundaries 82, 83, 84, and 85. Boundary 82 is the boundary between the first seal surface 81A and the second seal surface 81B. Boundary 83 is the boundary between the first seal surface 81A and the third seal surface 81C. Boundary 84 is the boundary between the fourth seal surface 81D and the second seal surface 81B. Boundary 85 is the boundary between the fourth seal surface 81D and the third seal surface 81C. The shape of boundaries 82 to 85 may be angular, or it may be rounded by R-processing. In this embodiment, boundaries 82 to 85 are angular.

[0050] The coating 80 is made of a resin material. Here, "made of a resin material" means that when the total mass of the materials constituting the coating 80 is considered to be 100% by mass, the resin material content is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In other words, the materials constituting the coating 80 may contain materials other than resin materials in addition to the resin material.

[0051] Specific examples of resins include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicon resin, and phenolic resin, as well as modified versions of these resins. The resin material may also be a mixture of these resins, a copolymer, or a modified version of a copolymer. Among these, the resin material is preferably a heat-fusible resin such as polyester or polyolefin, and more preferably polyolefin. When the resin material is a resin, the coating 80 may be molded by any molding method.

[0052] The resin material included in the material constituting the coating 80 is preferably an olefin-based random copolymer, more preferably contains a resin containing a polyolefin skeleton as its main component, more preferably contains polyolefin as its main component, and more preferably contains polypropylene as its main component. The polyolefin may be an acid-modified polyolefin. The resin material included in the material constituting the coating 80 preferably contains multiple types of amide lubricants. Furthermore, the resin material included in the material constituting the coating 80 preferably contains, in addition to saturated fatty acid amides, multiple types of amide lubricants, including unsaturated fatty acid amides. The resin material included in the material constituting the coating 80 may be a polyolefin resin to which a propylene-based elastomer with a melting point higher than 150°C has been added.

[0053] Examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyesters. Examples of copolymerized polyesters include copolymerized polyesters with ethylene terephthalate as the main repeating unit. Specifically, examples include copolymerized polyesters polymerized with ethylene isophthalate using ethylene terephthalate as the main repeating unit (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl dicarboxylate), and polyethylene (terephthalate / decanedicarboxylate). Among these, polybutylene terephthalate is preferred as the resin material from the viewpoint of improving heat resistance and pressure resistance.

[0054] Furthermore, specific examples of polyolefins include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylene such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymer of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymer of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. When polyolefin resins are copolymers, they may be block copolymers or random copolymers. Among these, polypropylene is preferred as the resin material because it has excellent heat-sealability and electrolyte resistance.

[0055] The resin material may contain fillers as needed. Specific examples of fillers include glass beads, graphite, glass fibers, and carbon fibers. By including the above-mentioned fillers in the resin material, the deformation resistance of the coating 80 to 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 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.

[0057] In this embodiment, the outer film 50 is wrapped around the electrode body 20 so as to have an opening 40A, and the first sealing portion 91 is formed by heat sealing the opposing surfaces (heat-fusible resin layers 53) of the outer film 50 together.

[0058] The first sealing portion 91 is formed by heat sealing the portion of the outer film 50, shown in Figure 3, that includes the first edge 50A and the portion that includes the second edge 50B. The first sealing portion 91 extends in the longitudinal direction (FB direction) of the outer body 40. The position in the outer body 40 where the first sealing portion 91 is formed can be arbitrarily selected. In this embodiment, it is preferable that the base 91X of the first sealing portion 91 is located on the edge 43 of the boundary between the first surface 41 and the second surface 42 of the outer body 40. The first surface 41 has a larger area than the second surface 42. The base 91X of the first sealing portion 91 may be located on any surface of the outer body 40. In this embodiment, the first sealing portion 91 protrudes outward from the electrode body 20 in a plan view. The first sealing portion 91 may be folded toward the second surface 42 of the outer body 40, or it may be folded toward the first surface 41.

[0059] In this embodiment, a second sealing portion 92 is formed by heat sealing the heat-fusible resin layer 53 of the outer film 50 and the lid sealing portion 81 of the lid 60. Hereinafter, the sealing strength between the heat-fusible resin layer 53 of the outer film 50 and the lid sealing portion 81 of the lid 60 may be referred to as the sealing strength of the second sealing portion 92. The sealing strength of the second sealing portion 92 is the sealing strength between the heat-fusible resin layer 53 and the lid 60 in the long side portion of the lid sealing portion 81, that is, the portion of the lid sealing portion 81 extending in the LR (width) direction in Figure 1A.

[0060] The seal strength of the second sealing section 92 is measured as follows. First, a cut is made in the portion of the outer film 50 that constitutes the first surface 41 of the outer body 40, forming three strip-shaped members 41X, 41Y, and 41Z (see the dashed line in Figure 1B) aligned in the LR direction. 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 60 in the second sealing section 92. The length of the lid 60 in the LR direction is 45 mm or more. Next, the seal strength of the strip-shaped members 41X, 41Y, and 41Z is measured by pulling the end of each strip-shaped member 41X, 41Y, and 41Z opposite to the end joined to the lid 60 upward in the UD direction (in the direction opposite to the first surface 41B). The distance between the chucks in the UD direction is 10 mm. The sealing strength of the strip members 41X, 41Y, and 41Z is the peak value of their respective sealing strengths. In this embodiment, the sealing strength of the second sealing portion 92 is the average value of the sealing strengths of the strip members 41X, 41Y, and 41Z. If the length of the lid 60 in the LR direction is less than 45 mm, three strip members with an arbitrary width X mm of less than 15 mm are formed, and the sealing strength of the three strip members is measured in the same manner as when the length of the lid 60 in the LR direction is 45 mm or more. The obtained sealing strengths are each divided by the arbitrary width X mm and multiplied by 15 to convert them to the sealing strengths of the three strip members at a width of 15 mm. The sealing strength of the second sealing portion 92 is the average value of the sealing strengths of the three strip members converted to a width of 15 mm. Note that if the lid 60 is divided into multiple parts including the long side and short side, the sealing strength of the second sealing portion 92 is the sealing strength of the long side portion of the lid sealing 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 outer casing 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 outer casing 40 is suitably maintained even if the energy 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 outer casing 40 is suitably maintained even if the energy 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. The 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.

[0062] In this embodiment, it is preferable that the lid 60 has a protruding portion 86 that protrudes from the lid sealing portion 81 so that a gap is less likely to form between the outer film 50 and the lid 60. The protruding portion 86 may be formed integrally with the covering 80, or it may be formed separately from the covering 80 and joined to the covering 80. In this embodiment, the protruding portion 86 is formed integrally with the covering 80. The position in the lid sealing portion 81 where the protruding portion 86 is formed can be arbitrarily selected. A gap between the outer film 50 and the lid 60 is likely to form, for example, between the base 91X of the first sealing portion 91 and the lid 60. In particular, when the base 91X of the first sealing portion 91 is located at the boundary 82 to boundary 85 of the lid 60, the resin filling performance between the base 91X of the first sealing portion 91 and the lid 60 tends to decrease. For this reason, it is preferable that the protruding portion 86 is formed in the lid sealing 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 60. Therefore, it is preferable that the protrusion 86 is formed at the boundary 82 in the lid sealing portion 81. In this embodiment, the first sealing portion 91 is sealed with the protrusion 86 sandwiched between them. The protrusion 86 may be formed on at least one of the first sealing surface 81A, the second sealing surface 81B, the third sealing surface 81C, the fourth sealing surface 81D, the boundary 83, the boundary 84, and the boundary 85.

[0063] The shape of the protrusion 86 can be arbitrarily selected. In this embodiment, the shape of the protrusion 86 is plate-like. The thickness of the protrusion 86 can be arbitrarily selected. In this embodiment, the thickness of the protrusion 86 decreases 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 it may increase as it moves away from the boundary 82.

[0064] The direction in which the protrusion 86 extends can be arbitrarily selected. In this embodiment, the protrusion 86 extends along a first direction (LR direction in this embodiment). The protrusion 86 may also extend along a second direction (UD direction in this embodiment). In a front view of the lid 60, the protrusion 86 may extend in a third direction that intersects the first direction (LR direction in this embodiment) and the second direction (UD direction in this embodiment).

[0065] The length of the protrusion 86 can be arbitrarily selected within a range less than or equal to 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 it may be 30% to 50% of the length of the first sealing portion 91.

[0066] <1-2. Method for manufacturing energy storage devices> Figure 10 is a flowchart showing an example of a method for manufacturing the energy storage device 10. The method for manufacturing the energy storage device 10 includes, for example, a first step, a second step, a third step, and a fourth step. Steps 1 to 4 are carried out, for example, by a manufacturing apparatus for the energy storage device 10. At least a portion of steps 1 to 4 may be carried out by an operator. Note that steps 1 to 4 are names for each step in the method for manufacturing the energy storage device 10, and do not necessarily indicate the order of the steps.

[0067] In the first step of step S11, the manufacturing apparatus places the cover bodies 60 on both ends of the electrode body 20 and connects the end 31 of the current collector 30 to the cover body 70 of the cover body 60. Upon completion of the first step, the cover bodies 60, which function as electrode terminals, 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 apparatus wraps the outer film 50 around the electrode body 20 and the lid 60 while tension is applied to the outer film 50, while restricting the movement of the electrode body 20 and the lid 60 with restricting means. The restricting means is, for example, a groove into which the electrode body 20 and the lid 60 are fitted. The restricting means may also be a device that applies an external force to the electrode body 20 and the lid 60 to prevent them from moving. The restricting means may also be a device that applies a force to the electrode body 20 and the lid 60 in the opposite direction to the direction in which the outer film 50 is pulled. The restricting means may also include a roller that runs on the outer film 50 while the outer film 50 is being pulled in order to remove wrinkles in the outer film 50.

[0069] The third step, S13, is performed after the second step. The manufacturing apparatus forms the second sealing portion 92 by heat sealing the outer film 50 and the lid 60.

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

[0071] <1-3. Function and Effects of Energy Storage Devices> In the energy storage device 10, the lid 60 is covered by a covering 80 made of a resin material, which provides high bonding strength between the covering 80 and the outer film 50. Therefore, the electrode body 20 can be suitably sealed by the outer casing 40.

[0072] [2. Variant] The embodiments described above are illustrative of possible forms of the lid, lid body, and energy storage device according to the present invention, and are not intended to limit their forms. The lid, lid body, and energy storage device according to the present invention may take forms different from those illustrated in the embodiments. One example is a form in which some of the configurations of the embodiments are replaced, modified, or omitted, or a form in which new configurations are added to the embodiments. Several examples of modifications of the embodiments are shown below. Note that the following modifications can be combined with each other as long as they do not contradict each other technically.

[0073] <2-1. First variation> In the energy storage device 10 of the above embodiment, the cover 60 does not necessarily have to have a protrusion 86. The first modified example can also be similarly applied to the second to eleventh modified examples described below.

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

[0075] In the second modified lid body 270, at least a portion of the through hole 72Z from the covering portion 72 may be omitted. At least a portion of the covering portion 72 may have a rough surface 73. The rough surface 73 can be formed, for example, by roughening the surface 72X of the covering portion 72. Specific methods for roughening include, for example, shot blasting, polishing, anodizing, wet etching, plasma treatment, laser treatment, sandblasting, or roughening 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 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 Figure 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 covering 80 is injection molded onto the lid body 270, the lid body 270 and the covering 80 are more firmly joined by an anchoring effect. To obtain a higher anchoring 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 according to JIS B 0601-2001. The measurement of the maximum height roughness Rz of the rough surface 73 is performed using a white light interferometer-equipped laser microscope VK-X3000 manufactured by Keyence Corporation.

[0076] In the second modification, from the viewpoint of suitably joining the lid body 270 and the covering 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 polar groups. The adhesive layer can be formed by dip coating, dispensing, inkjet, spraying, or screen printing.

[0077] In the second modification, the covering 80 may be joined to the lid body 270 by insert molding, press molding, induction heating and compression, laser heating, or friction stirring. In the second modification, from the viewpoint of improving the adhesion between the lid body 270 and the covering 80, at least one of the covering 80 and the rough surface 73 of the covering portion 72 may be subjected to anodizing or plating, and a resin reactive film may be formed. It is preferable that the rough surface 73 has a corrosion-resistant film as described in the barrier layer 52.

[0078] <2-3. Third Variation> Figure 13 is a front perspective view of the lid body 370 of the third modified example. The lid body 370 may have a rectangular housing 370X arranged in the space surrounded by the covering portion 72. The housing 370X may be formed integrally with the base portion 71, or it may be a separate component from the base portion 71 and joined to the base portion 71. The side surface of the housing 370X faces the back surface 72Y of the covering portion 72 with a small gap between them. The covering portion 80 may be arranged in the gap between the side surface of the housing 370X and the back surface 72Y of the covering portion 72. A housing portion 371X may be formed in the housing 370X. When a housing portion 371X is formed in the housing 370X, the lid 60 is positioned so that the opening of the housing portion 371X of the lid body 370 faces the electrode body 20.

[0079] <2-4. Fourth Variation> Figure 14 is a cross-sectional view of a power storage device 10 equipped with a lid body 470 of a fourth modified example. The covering portion 72 of the lid body 470 may have recesses 472Z that do not penetrate the covering portion 72, in place of or in addition to the through holes 72Z. The recesses 472Z may be recessed from the surface 72X toward the back surface 72Y, or recessed from the back surface 72Y toward the surface 72X. The specifications regarding the number of recesses 472Z formed in the covering portion 72 and the positions in 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 surface 72X of the covering portion 72.

[0080] <2-5. Fifth variation> Figure 15 is a cross-sectional view of a power storage device 10 equipped with a lid body 570 of a fifth modified example. The covering portion 72 of the lid body 570 may have protrusions 572Z projecting from the covering portion 72 toward the covering body 80, in place of or in addition to the through holes 72Z. The protrusions 572Z may project toward the covering body 80 from the surface 72X, or 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 on the covering portion 72 where the protrusions 572Z are formed, are the same as the specifications regarding the through holes 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 surface 72X of the covering portion 72.

[0081] <2-6. Sixth Variation> In the energy storage device 10 of the above embodiment, the housing 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, for example, to the first surface 71A of the base portion 71 of the lid body 70.

[0082] <2-7. Seventh Variation> In the above embodiment, the configuration of the housing portion 71X can be arbitrarily changed as long as it can be connected to the end portion 31 of the current collector 30. Figure 16 is a cross-sectional view of the seventh modified energy storage device 10. The seventh modified energy storage device 10 includes a housing portion 700. The housing portion 700 is, for example, a known clip. The housing portion 700 may also be a slide clip. The housing portion 700 includes a base portion 710 and a clamping portion 720. The base portion 710 is joined to the first surface 71A of the lid body 70. The clamping portion 720 is connected to the base portion 710 and is configured to clamp the portion of the current collector 30 including the end portion 31. In the seventh modified example, the current collector 30 and the lid body 70 can be connected by clamping the portion of the current collector 30 including the end portion 31 with the clamping portion 720, so the energy storage device 10 can be easily manufactured. Furthermore, if the housing 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 variation> In the energy storage device 10 of the above embodiment, the specific method for forming the protrusion 86 of the lid 60 can be arbitrarily changed. For example, the protrusion 86 may be formed by an adhesive film that is joined to the lid seal portion 81 of the lid body 70. In this modified example, for example, the protrusion 86 may be formed by joining multiple adhesive films to the lid seal portion 81 in an overlapping manner, or the protrusion 86 may be formed by joining an adhesive film to the lid seal portion 81 in a flap-like manner.

[0084] <2-9. Ninth Variation> In the above embodiment, the outer film 50 of the energy storage device 10 may extend outward in the FB direction beyond at least one of the two lids 60. The electrode body 20 is sealed when the portion of the outer film 50 that extends outward beyond the lids 60 is closed. The portion of the outer film 50 that extends outward beyond the lids 60 may be folded into a Goebeltop type pouch or a brick type pouch.

[0085] <2-10. 10th Variation> In the above embodiment, the outer casing 40 may not have one of the two lids 60. In this modification, in the FB direction, in the portion of the outer casing 40 where the lid 60 is omitted, the electrode body 20 is sealed by closing the portion of the outer film 50 that extends outward from the electrode body 20. The portion of the outer film 50 that extends outward from the electrode body 20 may be folded to form a Goebeltop type pouch or a brick type pouch.

[0086] <2-11. 11th Variation> In the above embodiment, the outer shape of the exterior body 40 can be arbitrarily changed. The outer shape of the exterior body 40 may be a cylinder, a prism, or a cube. [Explanation of Symbols]

[0087] 10: Energy storage devices 20: Electrode body 40: Exterior 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 cover used for the exterior of an energy storage device, A lid body made of metal material, A covering body comprising a resin material and covering a part of the lid body, The covering has a lid seal portion that is joined to the outer film, which is an element of the outer body, The aforementioned lid body is The covering portion covered by the aforementioned covering body, It has a part that is configured to be directly connected to the current collector, At least a portion of the covering portion is provided with a rough surface. Cover.

2. The lid body has a base portion which is configured to be directly connected to the current collector. The lid according to claim 1.

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

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

5. The covering portion is frame-shaped and rises 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 sealing portion is Multiple sealing surfaces that are joined to the aforementioned outer film, The boundaries of the plurality of sealing surfaces, At least one of the aforementioned boundaries is rounded. The lid according to claim 1 or 2.

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

9. A lid body that constitutes a lid used for the exterior of an energy storage device, The aforementioned lid body is It is composed of metal materials, A covering portion covered by a covering body made of a resin material, It has a part that is configured to be directly connected to the current collector, The covering has a lid seal portion that is joined to the outer film, which is an element of the outer body, At least a portion of the covering portion is provided with a rough surface. Lid body.

10. An electrode body including a current collector, The electrode body is enclosed by an outer casing, The exterior body is, The outer film enclosing the electrode body, A lid which is joined to the outer film, including, The aforementioned cover is A lid body made of metal material, A covering body comprising a resin material and covering a part of the lid body, The covering has a lid seal portion that is joined to the outer film, The aforementioned lid body is The covering portion covered by the aforementioned covering body, It has a portion configured to be directly connected to the current collector, At least a portion of the covering portion is provided with a rough surface. Energy storage device.

Images