Electricity storage device, conductive member, lid unit, and method for manufacturing an electricity storage device

Abstract

To provide a power storage device that can appropriately restrain a current collector, a conductive member used in the power storage device, a lid unit including the conductive member, and a manufacturing method for the power storage device.SOLUTION: A power storage device includes an electrode body including a current collector, an outer film wrapping the electrode body, a lid body configured to include a metal material to seal the electrode body together with the outer film, and a conductive member connected to the lid body and the current collector. The conductive member is arranged at least partially between the lid body and the electrode body.SELECTED DRAWING: Figure 5

Description

[Technical Field]

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

[0002] Patent Document 1 discloses an example of an electricity storage device. This electricity storage device includes an electrode assembly including a current collector, an exterior body that seals the electrode assembly, and an electrode terminal connected to the current collector. The exterior body includes an exterior film that encases the electrode assembly, and a lid that is joined to the exterior film. The electrode terminal is inserted into a through-hole formed in the lid. The current collector is joined to the electrode terminal. [Prior art documents] [Patent documents]

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

[0004] In order to suitably output electric power, it is preferable that the current collector be suitably constrained. In the above-described electricity storage device, there is room for improvement in terms of suitably constraining the current collector.

[0005] The present invention aims to provide an electricity storage device that can suitably restrain a current collector, a conductive member used in this electricity storage device, a lid unit including this conductive member, and a method for manufacturing the electricity storage device. [Means for solving the problem]

[0006] The electricity storage device according to a first aspect of the present invention comprises an electrode body including a current collector, an exterior film that wraps the electrode body, a lid body that contains a metal material and seals the electrode body together with the exterior film, and a conductive member that is connected to the lid body and the current collector, and the conductive member is disposed between the lid body and the electrode body.

[0007] An electricity storage device according to a second aspect of the present invention is the electricity storage device according to the first aspect, wherein the lid has a recess that houses at least a part of the conductive member.

[0008] An electricity storage device according to a third aspect of the present invention is the electricity storage device according to the first aspect, wherein the conductive member includes a base portion joined to the lid body and a clamping portion connected to the base portion and clamping the current collector.

[0009] A conductive member according to a fourth aspect of the present invention is a conductive member used in an electricity storage device, the electricity storage device comprising an electrode body including a current collector, an exterior film that wraps the electrode body, and a lid body that contains a metal material and seals the electrode body together with the exterior film, the conductive member being disposed between the lid body and the electrode body and connected to the lid body and the current collector.

[0010] A lid unit according to a fifth aspect of the present invention comprises the conductive member according to the fourth aspect, and the lid body joined to the conductive member.

[0011] A sixth aspect of the present invention relates to a method for manufacturing an electricity storage device, the method comprising: an electrode assembly including a current collector; an exterior film enclosing the electrode assembly; a lid including a metal material and sealing the electrode assembly together with the exterior film; and a conductive member connected to the lid and the current collector, the conductive member being disposed between the lid and the electrode assembly. The method for manufacturing the electricity storage device includes a first connecting step of connecting the current collector and the conductive member, and a second connecting step of connecting the conductive member to the lid.

[0012] A method for manufacturing an electricity storage device according to a seventh aspect of the present invention is the method for manufacturing an electricity storage device according to the sixth aspect, in which the first connecting step is carried out before the second connecting step.

[0013] An eighth aspect of the present invention provides an electricity storage device comprising: an electrode body including a current collector; an exterior film that wraps the electrode body; a lid that seals the electrode body together with the exterior film; and a conductive member connected to the lid body and the current collector, wherein the lid body has a first surface facing the electrode body, a second surface opposite to the first surface, and a through hole that penetrates the first surface and the second surface, and the conductive member includes a base that is joined to the current collector and a protrusion that is connected to the base and inserted into the through hole, and when viewed from the side or in a plan view, the thickness of the base is greater than the thickness of the protrusion.

[0014] An electricity accumulation device according to a ninth aspect of the present invention is the electricity accumulation device according to the eighth aspect, wherein a tip of the protrusion is positioned inside the through hole.

[0015] An electricity accumulation device according to a tenth aspect of the present invention is the electricity accumulation device according to the eighth aspect, wherein a tip of the protrusion is positioned outside the through hole.

[0016] An eleventh aspect of the present invention provides a conductive member for use in an electricity storage device, the electricity storage device comprising an electrode body including a current collector, an exterior film wrapping the electrode body, and a lid body sealing the electrode body together with the exterior film, the lid body having a first surface facing the electrode body, a second surface opposite the first surface, and a through hole penetrating the first surface and the second surface, the conductive member including a base joined to the current collector and a protrusion connected to the base and inserted into the through hole, and in a side view or a plan view, the thickness of the base is greater than the thickness of the protrusion.

[0017] A lid unit according to a twelfth aspect of the present invention comprises the conductive member according to the eleventh aspect, and the lid body joined to the conductive member.

[0018] A thirteenth aspect of the present invention provides a method for manufacturing an electricity storage device, the method comprising: an electrode assembly including a current collector; an exterior film wrapping the electrode assembly; a lid that seals the electrode assembly together with the exterior film; and a conductive member connected to the lid and the current collector, the lid having a first surface facing the electrode assembly, a second surface opposite the first surface, and a through hole penetrating the first surface and the second surface, the conductive member including a base joined to the current collector and a protrusion connected to the base and inserted into the through hole, the thickness of the base being greater than the thickness of the protrusion in a side view or a plan view. The method for manufacturing an electricity storage device includes a first connecting step of connecting the current collector and the conductive member, and a second connecting step of connecting the conductive member and the lid.

[0019] A method for manufacturing an electricity storage device according to a fourteenth aspect of the present invention is the method for manufacturing an electricity storage device according to the thirteenth aspect, in which the first connecting step is carried out before the second connecting step.

[0020] A fifteenth aspect of the present invention provides an electricity storage device comprising an electrode body including a current collector, an exterior film that wraps the electrode body, a lid that seals the electrode body together with the exterior film, and a conductive member that is connected to the lid and the current collector, wherein the conductive member includes a base that is joined to the current collector and a protrusion that is connected to the base and is inserted between the exterior film and the lid, and wherein the thickness of the base is greater than the thickness of the protrusion in a side view or a plan view.

[0021] A conductive member according to a sixteenth aspect of the present invention is a conductive member used in an electricity storage device, the electricity storage device comprising an electrode body including a current collector, an exterior film that wraps the electrode body, and a lid that seals the electrode body together with the exterior film, the conductive member comprising a base that is joined to the current collector, and a protrusion that is connected to the base and inserted between the exterior film and the lid, and in a side view or a plan view, the thickness of the base is greater than the thickness of the protrusion.

[0022] A lid unit according to a seventeenth aspect of the present invention comprises the conductive member according to the sixteenth aspect, and the lid body joined to the conductive member.

[0023] A method for manufacturing an electricity storage device according to an eighteenth aspect of the present invention is a method for manufacturing an electricity storage device comprising: an electrode assembly including a current collector; an exterior film wrapping the electrode assembly; a lid that seals the electrode assembly together with the exterior film; and a conductive member connected to the lid and the current collector, wherein the conductive member includes a base joined to the current collector and a protrusion connected to the base and inserted between the exterior film and the lid, and wherein the thickness of the base is greater than the thickness of the protrusion in a side view or a plan view. The method for manufacturing an electricity storage device comprises a first connecting step of connecting the current collector and the conductive member, and a second connecting step of connecting the conductive member and the lid.

[0024] A method for manufacturing an electricity storage device according to a nineteenth aspect of the present invention is the method for manufacturing an electricity storage device according to the eighteenth aspect, in which the first connecting step is carried out before the second connecting step. [Effects of the Invention]

[0025] According to the electricity storage device, conductive member, lid unit, and method for manufacturing an electricity storage device of the present invention, the current collector can be suitably restrained. [Brief explanation of the drawings]

[0026] [Figure 1A] FIG. 1 is a perspective view of an electricity storage device according to an embodiment. [Figure 1B] 2 is a diagram showing a method for measuring the seal strength of the second sealing portion of the electricity storage device in FIG. 1. FIG. [Figure 2] 2 is a cross-sectional view showing the layer structure of an exterior film included in the electricity storage device of FIG. 1. [Figure 3] FIG. 2 is a diagram showing the exterior film of the power storage device of FIG. 1 in an unfolded state. [Figure 4] FIG. 2 is a perspective view of a lid provided in the electricity storage device of FIG. 1. [Figure 5]1B is a cross-sectional view taken along line D5-D5 in FIG. 1A. [Figure 6] 2 is a flowchart showing an example of a manufacturing process for the electricity storage device of FIG. 1. [Figure 7] FIG. 10 is a cross-sectional view of an electricity accumulation device according to a first modified example. [Figure 8] FIG. 10 is a cross-sectional view of an electricity accumulation device according to a second modified example. [Figure 9] FIG. 11 is a cross-sectional view of an electricity accumulation device according to a third modified example. [Figure 10] FIG. 13 is a cross-sectional view of an electricity storage device according to a further modification of the third modification. [Figure 11] FIG. 11 is a cross-sectional view of an electricity accumulation device according to a fourth modified example. [Figure 12] FIG. 13 is a cross-sectional view of an electricity storage device according to a further modification of the fourth modification. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, an electricity storage device according to one embodiment of the present invention will be described with reference to the drawings. In this specification, a numerical range indicated by "to" means "greater than or equal to" or "less than or equal to." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less.

[0028] [Embodiment] <1-1. Configuration of the power storage device> FIG. 1A is a plan view schematically showing an electricity storage device 10 of an embodiment. FIG. 1B is a diagram relating to a method for measuring the seal strength of a second sealing portion 80 of the electricity storage device 10 of FIG. 1A. FIG. 2 is a cross-sectional view showing the layer structure of an exterior film 50 provided in the electricity storage device 10 of FIG. 1A. FIG. 3 is a diagram showing the exterior film 50 provided in the electricity storage device 10 of FIG. 1A in an unfolded state. FIG. 4 is a perspective view of a lid body 60 provided in the electricity storage device 10 of FIG. 1A. FIG. 5 is a cross-sectional view taken along line D5-D5 in FIG. 1A. In FIG. 1A, the direction of arrow UD indicates the thickness direction of the electricity storage device 10, the direction of arrow LR indicates the width direction of the electricity storage device 10, and the direction of arrow FB indicates the depth direction of the electricity storage device 10. The directions indicated by the arrows UD, LR, and FB are common to the subsequent figures.

[0029] The electricity storage device 10 includes an electrode assembly 20 including a current collector 31, a conductive member 32, and an exterior body 40. The electrode assembly 20 includes electrodes (positive and negative electrodes) constituting an electricity storage member such as a lithium-ion battery, a capacitor, an all-solid-state battery, a semi-solid battery, a quasi-solid battery, a polymer battery, an all-resin battery, a lead-acid battery, a nickel-metal hydride battery, a nickel-cadmium battery, a nickel-iron battery, a nickel-zinc battery, a silver oxide-zinc battery, a metal-air battery, a polyvalent cation battery, or a capacitor, as well as a separator. In this embodiment, the electrode assembly 20 has a substantially rectangular parallelepiped shape. Note that the term "substantially rectangular parallelepiped" includes not only a perfect rectangular parallelepiped, but also a solid that can be considered a rectangular parallelepiped by modifying the shape of a portion of its outer surface, for example. The electrode assembly 20 may have a cylindrical or polygonal prism shape, for example.

[0030] One end 31A of the current collector 31 (see FIG. 5) is connected to a conductive member 32 (see FIG. 5) described later.

[0031] The exterior body 40 seals the electrode body 20. The exterior body 40 includes an exterior film 50 and a lid 60. The exterior film 50 wraps the electrode body 20 so as to have an opening 40A. In this embodiment, the exterior film 50 is wrapped around the electrode body 20 so as to have the opening 40A. The lid 60 is placed on the side of the electrode body 20 so as to close the opening 40A. Note that the electrode body 20 may be housed inside the exterior film 50 that is configured in a cylindrical shape so as to form the opening 40A, and the opening 40A may be closed by the lid 60.

[0032] For example, there is a method of forming a storage portion (recess) in the exterior film 50 through cold forming to store the electrode assembly 20. However, it is not necessarily easy to form a deep storage portion using this method. Attempting to form a deep storage portion (recess) through cold forming (for example, a forming depth of 15 mm) increases the likelihood of pinholes or cracks occurring in the exterior film 50, resulting in a decrease in battery performance. On the other hand, the exterior body 40 seals the electrode assembly 20 by wrapping the exterior film 50 around the electrode assembly 20, and therefore can easily seal the electrode assembly 20 regardless of the thickness of the electrode assembly 20. Note that in order to reduce the dead space between the electrode assembly 20 and the exterior film 50 and improve the volumetric energy density of the power storage device 10, it is preferable that the exterior film 50 be wrapped so as to contact the outer surface of the electrode assembly 20. Furthermore, in all-solid-state batteries, it is necessary to apply a high pressure uniformly from the outer surface of the battery to maximize battery performance, so it is necessary to eliminate the space between the electrode assembly 20 and the exterior film 50. Therefore, it is preferable that the exterior film 50 be wrapped so as to contact the outer surface of the electrode assembly 20.

[0033] As shown in FIG. 2 , the exterior film 50 is a laminate (laminate film) having, for example, a base material layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in this order. Note that the exterior film 50 does not need to include all of these layers; for example, it may not include the barrier layer 52. That is, the exterior film 50 may be made of any flexible and easily bendable material, such as a resin film. Note that the exterior film 50 is preferably heat-sealable. The innermost and outermost layers of the exterior film 50 may be heat-sealable resin layers 53. In this case, the exterior film 50 may encase the electrode assembly 20 and the lid 60 by joining the outermost and innermost layers.

[0034] The substrate layer 51 included in the exterior film 50 is a layer that imparts heat resistance to the exterior film 50 and prevents pinholes from forming during processing or distribution. The substrate layer 51 is composed of, for example, at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer in the substrate layer 51, the barrier layer 52 can be protected during processing of the exterior film 50, and breakage of the exterior film 50 can be prevented. Furthermore, from the viewpoint of increasing the tensile elongation of the exterior film 50, the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer. Furthermore, from the viewpoint of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially stretched polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially stretched nylon (ONy) film. The substrate layer 51 may be composed of both a stretched polyester resin layer and a stretched polyamide resin layer. The thickness of the base layer 51 is preferably, for example, 5 to 300 μm, and more preferably 5 to 150 μm, from the viewpoint of film strength.

[0035] The barrier layer 52 is a layer that prevents at least moisture from penetrating. The barrier layer 52 is bonded to the base layer 51 via, for example, an adhesive layer 54. Examples of the barrier layer 52 include metal foils, vapor-deposited films, and resin layers with barrier properties. Vapor-deposited films include metal vapor-deposited films, inorganic oxide vapor-deposited films, and carbon-containing inorganic oxide vapor-deposited films. Resin layers include fluorine-containing resins such as polyvinylidene chloride, polymers based on chlorotrifluoroethylene (CTFE), polymers based on tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers based on fluoroalkyl units, as well as ethylene-vinyl alcohol copolymers. Other examples of the barrier layer 52 include resin films having at least one of these vapor-deposited films and resin layers. The barrier layer 52 may be formed of multiple layers. The barrier layer 52 preferably includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 52 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, it is preferable that the metal material contains at least one of an aluminum alloy foil and a stainless steel foil.

[0036] In the barrier layer 52, the layer made of the aforementioned metallic material may contain recycled metallic material. Examples of recycled metallic material include recycled aluminum alloy, stainless steel, titanium steel, and steel plate. These recycled materials can be obtained by known methods. Recycled aluminum alloy material can be obtained, for example, by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 52 may be made solely of recycled material, or may be made of a mixture of recycled and virgin material. Note that recycled metallic material refers to metallic material that has been made reusable by collecting, isolating, and refining various products used in the market or waste from manufacturing processes. Furthermore, virgin metallic material refers to new metallic material refined from natural metallic resources (raw materials) and is not recycled material.

[0037] From the viewpoint of improving the formability or conformability of the exterior film 50, the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy. From the viewpoint of further improving the formability or conformability, an iron-containing aluminum alloy foil is preferred. In the iron-containing aluminum alloy foil (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. By having an iron content of 0.1% by mass or more, an exterior film 50 with better formability can be obtained. By having an iron content of 9.0% by mass or less, an exterior film 50 with better flexibility can be obtained. Furthermore, silicon, magnesium, copper, manganese, etc. may be added as necessary. Furthermore, softening can be achieved by annealing or the like. From the viewpoint of improving the mechanical strength of the exterior film 50, the aluminum alloy foil is more preferably a hard aluminum alloy foil made of, for example, a work-hardened aluminum alloy.

[0038] Examples of stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. Furthermore, from the viewpoint of providing an exterior film 50 with excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0039] Specific examples of austenitic stainless steels that can be used to form the stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred.

[0040] In the case of a metal foil, the thickness of the barrier layer 52 should be sufficient to at least function as a barrier layer that prevents moisture penetration, and may be, for example, about 9 to 200 μm. The thickness of the barrier layer 52 is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and particularly preferably about 35 μm or less. The thickness of the barrier layer 52 is preferably about 9.0 μm or more, more preferably about 20 μm or more, and more preferably about 25 μm or more. Preferred ranges for the thickness of the barrier layer 52 include about 9.0 to 85 μm, about 9.0 to 50 μm, about 9.0 to 40 μm, about 9.0 to 35 μm, about 20 to 85 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 35 μm, about 25 to 85 μm, about 25 to 50 μm, about 25 to 40 μm, and about 25 to 35 μm. When the barrier layer 52 is made of aluminum alloy foil, the above-mentioned ranges are particularly preferred. From the viewpoint of imparting high formability and high rigidity to the exterior film 50, the thickness of the barrier layer 52 is preferably about 35 μm or more, more preferably about 45 μm or more, even more preferably about 50 μm or more, and even more preferably about 55 μm or more, and is preferably about 200 μm or less, more preferably about 85 μm or less, even more preferably about 75 μm or less, and even more preferably about 70 μm or less. Preferred ranges are approximately 35 to 200 μm, approximately 35 to 85 μm, approximately 35 to 75 μm, approximately 35 to 70 μm, approximately 45 to 200 μm, approximately 45 to 85 μm, approximately 45 to 75 μm, approximately 45 to 70 μm, approximately 50 to 200 μm, approximately 50 to 85 μm, approximately 50 to 75 μm, approximately 50 to 70 μm, approximately 55 to 200 μm, approximately 55 to 85 μm, approximately 55 to 75 μm, and approximately 55 to 70 μm. The high formability of the exterior film 50 facilitates deep drawing, which can contribute to increasing the capacity of the electricity storage device. Furthermore, while increasing the capacity of the electricity storage device increases the weight of the electricity storage device, increasing the rigidity of the exterior film 50 can contribute to high sealing performance of the electricity storage device.In particular, when the barrier layer 52 is made of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Preferred ranges for the thickness of the stainless steel foil include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0041] Furthermore, when the barrier layer 52 is an aluminum foil, it is preferable that a corrosion-resistant coating be provided on at least the surface opposite the substrate layer 51 to prevent dissolution and corrosion. The barrier layer 52 may be provided with a corrosion-resistant coating on both sides. Here, the corrosion-resistant coating refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) by performing, for example, a hydrothermal conversion treatment such as boehmite treatment, a chemical conversion treatment, an anodizing treatment, a plating treatment using nickel or chromium, or a corrosion prevention treatment such as applying a coating agent on the surface of the barrier layer 52. Specifically, the corrosion-resistant coating refers to a coating that improves the acid resistance of the barrier layer 52 (acid-resistant coating), a coating that improves the alkali resistance of the barrier layer 52 (alkali-resistant coating), or the like. The corrosion-resistant coating may be formed by one type of treatment or a combination of two or more types. Furthermore, the barrier layer 52 may be formed not only as a single layer but also as a multi-layer. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the surface of the metal foil is dissolved using a treatment agent to form a metal compound with excellent corrosion resistance. Note that these treatments may also be included in the definition of chemical conversion treatment. Furthermore, if the barrier layer 52 has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer 52.

[0042] The corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 during molding of the exterior film 50, prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride produced by a reaction between an electrolyte and water, and particularly prevents dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52 when the barrier layer 52 is an aluminum alloy foil, and also improves the adhesion (wettability) of the surface of the barrier layer 52, thereby preventing delamination between the base layer 51 and the barrier layer 52 during heat sealing and between the base layer 51 and the barrier layer 52 during molding.

[0043] The heat-sealable resin layer 53 is bonded to the barrier layer 52 via, for example, an adhesive layer 55. The heat-sealable resin layer 53 included in the exterior film 50 is a layer that provides heat-sealing properties to the exterior film 50. Examples of the heat-sealable resin layer 53 include resin films made of polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins and polypropylene resins, or acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. From the viewpoints of sealability and strength, the thickness of the heat-sealable resin layer 53 is preferably, for example, 20 to 300 μm, and more preferably 40 to 150 μm.

[0044] The exterior film 50 preferably has one or more layers with a buffer function (hereinafter referred to as "buffer layer") outside the heat-sealable resin layer 53, more preferably outside the barrier layer 52. The buffer layer may be laminated on the outside of the base material layer 51, or the base material layer 51 may also function as a buffer layer. When the exterior film 50 has multiple buffer layers, the multiple buffer layers may be adjacent to each other, or may be laminated with the base material layer 51, the barrier layer 52, or the like interposed therebetween.

[0045] The material constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. Examples of the material having cushioning properties include rubber, nonwoven fabric, and foam sheet. Examples of rubber include natural rubber, fluororubber, and silicone rubber. The rubber hardness is preferably about 20 to 90. The material constituting the nonwoven fabric is preferably a material having excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and even more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the thickness of the buffer layer is preferably 5000 μm, and even more preferably 3000 μm. The thickness of the buffer layer is preferably in the range of 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm, and most preferably in the range of 1000 μm to 3000 μm.

[0046] When the buffer layer is made of rubber, the lower limit of the buffer layer thickness is preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit of the buffer layer thickness is preferably 10 mm, more preferably 5 mm, and even more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the buffer layer thickness is 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0047] When the exterior film 50 has a buffer layer, the buffer layer functions as a cushion, thereby preventing the exterior film 50 from being damaged by impact when the energy storage device 10 is dropped or by handling during the manufacture of the energy storage device 10.

[0048] The lid body 60 shown in FIG. 4 has, for example, a rectangular parallelepiped shape and is made of a metal material. In this embodiment, the lid body 60 is made of a metal material and therefore functions as an electrode terminal. Therefore, the electricity storage device 10 has fewer components than conventional electricity storage devices. When the lid body 60 is made of a metal material, it preferably has the corrosion-resistant coating described in the barrier layer 52. The lid body 60 has a first surface 61, a second surface 62, and a sealing surface 63. The first surface 61 faces the electrode assembly 20. The second surface 62 is the surface opposite to the first surface 61. For example, an electrode terminal may be bonded to the second surface 62 of the lid body 60. The sealing surface 63 is connected to the first surface 61 and the second surface 62 and is bonded to the heat-sealable resin layer 53 of the exterior film 50. In order to suitably bond the lid 60 and the exterior film 50, the sealing surface 63 of the lid 60 is preferably bonded via an adhesive film 90 (see FIG. 5). The sealing surface 63 may be bonded to the exterior film 50 via an adhesive layer in addition to or instead of the adhesive film 90. The adhesive film 90 or adhesive layer may be a single layer or a multilayer, and preferably contains at least a resin material having a polar group. The adhesive layer can be formed by dip coating, a dispenser, inkjet printing, spraying, screen printing, or the like. At least one of the adhesive film 90 and the adhesive layer may be provided on a location of the lid 60 other than the sealing surface 63.

[0049] The lid 60 is made of a metal material. Here, "made of a metal material" means that, when the entire material constituting the lid 60 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 60 can contain materials other than metal materials in addition to metal materials.

[0050] The adhesive film 90 can be any film that can bond the exterior film 50 and the lid 60. The adhesive film 90 is preferably a laminated film having at least a heat-sealable resin layer, a heat-resistant substrate layer, and a heat-sealable resin layer, in this order. The specifications for the heat-sealable resin layer of the adhesive film 90 are the same as those for the heat-sealable resin layer 53. The materials constituting the heat-sealable resin layers on both sides of the adhesive film 90 may be the same or different, and are appropriately selected according to the materials constituting the heat-sealable resin layer 53 of the exterior film 50 and the material constituting the lid 60. The material constituting the heat-sealable resin layer of the adhesive film 90 on the side that is bonded to the lid 60 is preferably an acid-modified polyolefin resin graft-modified with an acid such as maleic anhydride. The heat-sealable resin layer of the adhesive film 90 on the side that is bonded to the exterior film 50 is preferably made of the same type of material as the material that constitutes the heat-sealable resin layer 53 of the exterior film 50 .

[0051] The heat-resistant substrate layer may be any film made of a heat-resistant resin, such as a non-stretched or stretched film of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polymethylpentene (registered trademark), polyacetal cyclic polyolefin, polyethylene, polypropylene, etc. Polyethylene terephthalate is particularly preferred because it is inexpensive and has high strength.

[0052] The adhesive film 90 preferably has adhesiveness. When the second sealing portion 80 is formed with the adhesive film 90 disposed between the exterior film 50 and the lid 60, the adhesive film 90 is less likely to shift position relative to the lid 60 and the exterior film 50. By incorporating a tackifying resin into the heat-sealable resin layer of the adhesive film 90, adhesiveness can be imparted to the adhesive film 90. Examples of the tackifying resin include amorphous polyolefins. Examples of amorphous polyolefins include amorphous polypropylene and copolymers of amorphous propylene and other α-olefins. The content of the tackifying resin relative to the base material constituting the heat-sealable resin is preferably 10 to 20 wt % or less.

[0053] The sealing surface 63 includes a first sealing surface 63A, a second sealing surface 63B, a third sealing surface 63C, and a fourth sealing surface 63D. The first sealing surface 63A constitutes the upper surface of the lid body 60. The first sealing surface 63A extends in a first direction (the LR direction in this embodiment) when viewed from the front of the lid body 60. The second sealing surface 63B and the third sealing surface 63C are connected to the first sealing surface 63A and constitute the side surfaces of the lid body 60. The second sealing surface 63B and the third sealing surface 63C extend in a second direction (the UD direction in this embodiment) that intersects with the first direction when viewed from the front of the lid body 60. In this embodiment, the first direction and the second direction are orthogonal when viewed from the front of the lid body 60. The first direction and the second direction do not have to be orthogonal when viewed from the front of the lid body 60. The fourth sealing surface 63D constitutes the lower surface of the lid body 60. The fourth sealing surface 63D extends in a first direction (LR direction in this embodiment) when the lid 60 is viewed from the front.

[0054] When the lid body 60 is plate-shaped, it is preferable that the lid body 60 has a certain thickness so that deformation of the exterior body 40 is suppressed even when the electricity storage device 10 is placed on top of it. From another perspective, when the lid body 60 is plate-shaped, it is preferable that the sealing surface 63 of the lid body 60 has a certain thickness so that the sealing surface 63 of the lid body 60 and the exterior film 50 can be heat-sealed appropriately when forming the second sealing portion 80 described below. The minimum thickness of the lid body 60 is 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum thickness of the lid body 60 is, for example, 20 mm, more preferably 8.0 mm, and even more preferably 7.0 mm. The maximum thickness of the lid body 60 may be 20 mm or more. The preferred ranges for the thickness of the material constituting the lid body 60 are 1.0 mm to 20 mm, 1.0 mm to 15 mm, 1.0 mm to 10 mm, 3.0 mm to 20 mm, 3.0 mm to 15 mm, 3.0 mm to 10 mm, 4.0 mm to 20 mm, 4.0 mm to 15 mm, and 4.0 mm to 10 mm. The thickness of the lid body 60 may vary depending on the region of the lid body 60. When the thickness of the lid body 60 varies depending on the region, the thickness of the lid body 60 is the thickness of the thickest portion.

[0055] The cover 60 further includes boundaries 64, 65, 66, and 67. The boundary 64 is the boundary between the first seal surface 63A and the second seal surface 63B. The boundary 65 is the boundary between the first seal surface 63A and the third seal surface 63C. The boundary 66 is the boundary between the fourth seal surface 63D and the second seal surface 63B. The boundary 67 is the boundary between the fourth seal surface 63D and the third seal surface 63C. The boundaries 64 to 67 may have angular shapes, or may be rounded by being subjected to R machining. In this embodiment, the boundaries 64 to 67 are angular.

[0056] In this embodiment, in order to suitably join the end 31A of the current collector 31, a conductive member 32 is disposed separately from the lid body 60, which functions as an electrode terminal. The entire conductive member 32 is disposed between the electrode body 20 and the lid body 60. The conductive member 32 is configured to include a metal material. Examples of the metal material constituting the conductive member 32 include aluminum, nickel, and copper. For example, if the electrode body 20 is a lithium ion battery, the conductive member 32 connected to the positive electrode is preferably made of aluminum or the like, and the conductive member 32 connected to the negative electrode is preferably made of copper, nickel, or the like. The lid unit 60Z is configured by joining the conductive member 32 and the lid body 60.

[0057] The conductive member 32 is made of a metal material. Here, "made of a metal material" means that, when the entire material constituting the conductive member 32 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 conductive member 32 can contain materials other than metal materials in addition to metal materials.

[0058] The shape of the conductive member 32 can be selected arbitrarily as long as it can be bonded to the end portion 31A of the current collector 31. In this embodiment, the shape of the conductive member 32 is a rectangular parallelepiped. The shape of the conductive member 32 may also be a cube, a polygonal prism, a polygonal pyramid, a cylinder, or a sphere.

[0059] The conductive member 32 has a first surface 32A and a second surface 32B. The first surface 32A is joined to the first surface 61 of the lid 60 by, for example, welding. The second surface 32B is joined to the end 31A of the current collector 31 by, for example, welding. The second surface 32B and the end 31A of the current collector 31 may be joined by screw fastening, press fitting, shrink fitting, caulking welding, pressure welding, brazing, or an adhesive. When the second surface 32B and the end 31A of the current collector 31 are joined by an adhesive, the second surface 32B and the end 31A of the current collector 31 only need to be conductive in at least one of the portions joined by the adhesive and the portions other than the portions joined by the adhesive.

[0060] The number of conductive members 32 arranged in one electricity storage device 10 can be selected arbitrarily. In this embodiment, one conductive member 32 is arranged on each of the positive electrode side and the negative electrode side. Two or more conductive members 32 may be arranged on each of the positive electrode side and the negative electrode side, and the number of conductive members 32 arranged on the positive electrode side may be different from the number of conductive members 32 arranged on the negative electrode side.

[0061] From the viewpoint of suppressing energy loss, at least one of the sum SA of the cross-sectional areas of the conductive members 32 on the positive electrode side and the sum SB of the cross-sectional areas of the conductive members 32 on the negative electrode side is set to 4 mm 2 It is preferable that the cross-sectional area of ​​the conductive member 32 is equal to or greater than 1 / 2. The cross-sectional area of ​​the conductive member 32 is the area of ​​a cross section of the conductive member 32 cut in a direction perpendicular to the direction of current flow in the conductive member 32 when viewed from the side. When one conductive member 32 is arranged on the positive electrode side, the sum SA is the cross-sectional area of ​​one conductive member 32. When one conductive member 32 is arranged on the negative electrode side, the sum SB is the cross-sectional area of ​​one conductive member 32. When multiple conductive members 32 are arranged on the positive electrode side, the sum SA is the sum of the cross-sectional areas of the multiple conductive members 32. When multiple conductive members 32 are arranged on the negative electrode side, the sum SB is the sum of the cross-sectional areas of the multiple conductive members 32.

[0062] In this embodiment, the first sealing portion 70 is formed by wrapping the exterior film 50 around the electrode body 20 so as to have an opening 40A, and then heat-sealing the opposing surfaces (heat-fusible resin layers 53) of the exterior film 50 together.

[0063] The first sealed portion 70 is formed by heat-sealing a portion of the exterior film 50 including the first edge 50A and a portion of the exterior film 50 including the second edge 50B shown in FIG. 3 . The first sealed portion 70 extends in the longitudinal direction of the exterior body 40. The position at which the first sealed portion 70 is formed in the exterior body 40 can be selected arbitrarily. In the present embodiment, the base 70X of the first sealed portion 70 is preferably located on the edge 43 at the boundary between the first surface 41 and the second surface 42 of the exterior body 40. The first surface 41 has a larger area than the second surface 42. The base 70X of the first sealed portion 70 may be located on any surface of the exterior body 40. In the present embodiment, the first sealed portion 70 protrudes outward beyond the electrode assembly 20 in a plan view. The first sealed portion 70 may be folded, for example, toward the second surface 42 or the first surface 41 of the exterior body 40.

[0064] In this embodiment, the second sealed portion 80 is formed by heat-sealing the heat-sealable resin layer 53 of the exterior film 50 and the sealing surface 63 of the lid 60. Hereinafter, the seal strength between the heat-sealable resin layer 53 of the exterior film 50 and the sealing surface 63 of the lid 60 may be referred to as the seal strength of the second sealed portion 80. The seal strength of the second sealed portion 80 is the seal strength between the heat-sealable resin layer 53 and the lid 60 at the long side portion of the sealing surface 63, i.e., the seal strength at the sealing surface 63 extending in the L-R (width) direction in FIG. 1 .

[0065] The seal strength of the second sealing portion 80 is measured as follows. First, a slit is made in the portion of the exterior film 50 that constitutes the first surface 41 of the exterior body 40, forming three strip-shaped members 41X, 41Y, and 41Z aligned in the L-R direction (see the two-dot chain lines in FIG. 1B). The width of the three strip-shaped members 41X, 41Y, and 41Z in the L-R direction is 15 mm. The ends of the strip-shaped members 41X, 41Y, and 41Z are joined to the lid body 60 at the second sealing portion 80. The length of the lid body 60 in the L-R direction is 45 mm or more. Next, the end of each of the strip-shaped members 41X, 41Y, and 41Z opposite the end joined to the lid body 60 is pulled upward in the UD direction (away from the first surface 41B), thereby measuring the seal strength of each of the strip-shaped members 41X, 41Y, and 41Z. The distance between the zippers in the UD direction is 10 mm. The seal strength of the strip-shaped members 41X, 41Y, and 41Z is the peak value of each seal strength. In this embodiment, the seal strength of the second sealing portion 80 is the average value of the seal strengths of the strip-shaped members 41X, 41Y, and 41Z. When the length of the lid body 60 in the L-R direction is less than 45 mm, three strip-shaped members with an arbitrary width X mm, less than 15 mm, are formed, and the seal strengths of the three strip-shaped members are measured using the same method as when the length of the lid body 60 in the L-R direction is 45 mm or more. The obtained seal strengths are each divided by the arbitrary width X mm and multiplied by 15 to convert them to the seal strengths of the three strip-shaped members in a 15 mm width. The seal strength of the second sealing portion 80 is the average value of the seal strengths of the three strip-shaped members converted to a 15 mm width. Note that when the lid body 60 is divided into multiple parts including long and short sides, the seal strength of the second sealing portion 80 is the seal strength of the long sides of the sealing surfaces 63 of the multiple parts.

[0066] From the viewpoint of suitably maintaining the state in which the electrode assembly 20 is sealed by the exterior housing 40, the seal strength of the second sealing unit 80 is preferably 40 N / 15 mm or more, more preferably 50 N / 15 mm or more, even more preferably 60 N / 15 mm or more, even more preferably 70 N / 15 mm or more, and even more preferably 85 N / 15 mm or more. When the seal strength of the second sealing unit 80 is 40 N / 15 mm or more, the state in which the electrode assembly 20 is sealed by the exterior housing 40 is suitably maintained even after the electricity storage device 10 has been used for, for example, several years (less than 10 years). When the seal strength of the second sealing unit 80 is 85 N / 15 mm or more, the state in which the electrode assembly 20 is sealed by the exterior housing 40 is suitably maintained even after the electricity storage device 10 has been used for, for example, 10 years or more. The seal strength of the second sealing unit 80 is preferably 300 N / 15 mm or less. A preferred range for the seal strength of the second sealing portion 80 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.

[0067] <1-2. Method for manufacturing electricity storage devices> 6 is a flowchart showing an example of a method for manufacturing the electricity storage device 10. The method for manufacturing the electricity storage device 10 includes, for example, a first step, a second step, a third step, a fourth step, and a fifth step. The first step to the fifth step are performed, for example, by a manufacturing apparatus for the electricity storage device 10. At least some of the first step to the fifth step may be performed by an operator. Note that the first step to the fifth step are simply names of the steps in the method for manufacturing the electricity storage device 10 defined for convenience, and do not necessarily indicate the order of the steps.

[0068] In the first step (first connection step) of step S11, the manufacturing equipment joins the end portion 31A of the current collector 31 and the second surface 32B of the conductive member 32. By performing the first step before the second step described below, the current collector 31 and the conductive member 32 can be easily joined.

[0069] The second process (second connection process) of step S12 is performed after the first process. In the second process, the manufacturing equipment joins the first surface 32A of the conductive member 32 and the first surface 61 of the lid body 60. The second process may be performed before the first process or after the third process described below.

[0070] The third step of step S13 is performed after the first step. In the third step, the manufacturing apparatus winds the exterior film 50 around the electrode assembly 20 and the lid body 60 while tension is applied to the exterior film 50, while restricting the movement of the electrode assembly 20 and the lid body 60 with a restricting means. The restricting means is, for example, a groove into which the electrode assembly 20 and the lid body 60 are fitted. The restricting means may be a device that applies an external force to the electrode assembly 20 and the lid body 60 to prevent the electrode assembly 20 and the lid body 60 from moving. The restricting means may be a device that applies a force to the electrode assembly 20 and the lid body 60 in a direction opposite to the direction in which the exterior film 50 is pulled. 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.

[0071] The fourth step of step S14 is carried out after the third step. The manufacturing device forms the second sealed portion 80 by heat-sealing the exterior film 50 and the lid 60 together.

[0072] The fifth step of step S15 is performed before or after the fourth step. In the fifth step, the manufacturing apparatus forms a first sealing portion 70 by heat-sealing the heat-sealable resin layer 53 in a portion including the first edge 50A of the exterior film 50 and the heat-sealable resin layer 53 in a portion including the second edge 50B while restricting movement of the electrode body 20 and the lid body 60 and applying tension to the exterior film 50 so that the protruding portion 68 of the lid body 60 is sandwiched between the exterior film 50.

[0073] <1-3. Actions and Effects of Electricity Storage Devices> According to the electricity storage device 10, the conductive member 32 is disposed between the electrode body 20 and the lid body 60, and therefore the end portion 31A of the current collector 31 can be suitably restrained.

[0074] [2. Modifications] The above-described embodiments are examples of possible forms of the electricity storage device, conductive member, lid unit, and method for manufacturing an electricity storage device according to the present invention, and are not intended to limit the forms. The electricity storage device, conductive member, lid unit, and method for manufacturing an electricity storage device according to the present invention may take forms different from those exemplified in the embodiments. Examples include forms in which part of the configuration of the embodiments is replaced, modified, or omitted, or forms in which a new configuration is added to the embodiments. Some examples of modified embodiments are shown below. Note that the following modified forms can be combined with each other as long as there is no technical contradiction.

[0075] <2-1. First modified example> In the above embodiment, the configuration of the lid body 60 can be changed as long as it can be bonded to the conductive member 32. As shown in FIG. 7, the lid body 60 may have a recess 60X recessed from the first surface 61 toward the second surface 62. The recess 60X does not penetrate the lid body 60. The inner shape of the recess 60X preferably corresponds to the outer shape of the conductive member 32. At least a portion of the conductive member 32 is housed in the recess 60X. In the example shown in FIG. 7, a portion of the conductive member 32 including the second surface 32B is exposed from the recess 60X.

[0076] <2-2. Second modified example> In the above embodiment, the configuration of the conductive member 32 can be modified as desired as long as it can be connected to the end 31A of the current collector 31. FIG. 8 is a cross-sectional view of an electricity storage device 10 including a conductive member 232 according to a second modification. The conductive member 232 is, for example, a known clip. The conductive member 232 may also be a slide clip. The conductive member 232 includes a base 232A and a clamping portion 232B. The base 232A is joined to the first surface 61 of the lid 60. The clamping portion 232B is connected to the base 232A and configured to clamp a portion of the current collector 31 that includes the end 31A. In the second modification, the current collector 31 and the conductive member 32 can be connected by clamping a portion of the current collector 31 that includes the end 31A with the clamping portion 232B, thereby facilitating the manufacture of the electricity storage device 10. Furthermore, when the conductive member 232 is a slide clip, in the FB direction, the current collector 31 can be inserted into the clamping portion 232B in a direction approaching the base 232A, but movement in a direction away from the base 232A is restricted by the clamping portion 232B. Therefore, the state in which the current collector 31 is clamped by the clamping portion 232B is suitably maintained.

[0077] <2-3.Third modified example> In the above embodiment, the configurations of the lid body 60 and the conductive member 32 may be modified as shown in Fig. 9. Fig. 9 is a cross-sectional view of the electricity storage device 10 of a third modified example. The electricity storage device 10 of the third modified example includes a lid body 360 and a conductive member 332.

[0078] The lid 360 has a through-hole 60Y formed therein, penetrating the first surface 61 and the second surface 62. In the third modification, the material constituting the lid 360 can be selected arbitrarily. The material constituting the lid 360 may be a metal material or a resin material. The material constituting the lid 360 may include at least two or more types of materials selected from a metal oxide, a carbon material, and a rubber material. The material constituting the lid 360 may include all of a metal oxide, a carbon material, and a rubber material.

[0079] When the lid body 360 is plate-shaped, it is preferable that the lid body 360 have a certain thickness so that deformation of the exterior body 40 is suppressed even when the power storage device 10 is placed on top of it. From another perspective, when the lid body 360 is plate-shaped, it is preferable that the sealing surface 63 of the lid body 360 have a certain thickness so that the sealing surface 63 of the lid body 360 and the exterior film 50 can be heat-sealed appropriately when the second sealing portion 80 is formed. The minimum thickness of the lid body 360 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum thickness of the lid body 360 is, for example, 20 mm, more preferably 8.0 mm, and even more preferably 7.0 mm. The maximum thickness of the lid body 360 may be 20 mm or more. The preferred ranges for the thickness of the material constituting the lid body 360 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 the third modified example, when the lid body 360 is described as being plate-shaped, this does not include an embodiment in which the lid body 360 is composed solely of a film as defined by the JIS (Japanese Industrial Standards) "Packaging Terminology" standard. The thickness of the lid body 360 may vary depending on the region of the lid body 360. When the thickness of the lid body 360 varies depending on the region, the thickness of the lid body 360 is the thickness of the thickest portion.

[0080] The conductive member 332 includes a base 332A and a protruding portion 332B connected to the base 332A. The base 332A and the protruding portion 332B may be integrally formed, or may be formed as separate bodies and joined together.

[0081] At least one of the base 332A and the protrusion 332B is joined to a desired location on the lid 360. In the example shown in FIG. 9, the base 332A is joined to the first surface 61 of the lid 360 by, for example, welding. The base 332A may be joined to the first surface 61 of the lid 360 by screw fastening, press fitting, shrink fitting, crimp welding, pressure welding, brazing, or an adhesive. When the base 332A and the first surface 61 of the lid 360 are joined by an adhesive, it is sufficient that at least one of the portions of the base 332A and the first surface 61 of the lid 360 joined by the adhesive and the portions other than the portions joined by the adhesive are conductive. The base 332A and the first surface 61 of the lid 360 may be joined by crimping. When the base 332A and the first surface 61 of the lid 360 are joined by caulking, an adhesion assisting member may be disposed between the base 332A and the first surface 61 of the lid 360. The adhesion assisting member is, for example, a foam material, a sponge, a resin, or a rubber. From the viewpoint of connecting a larger number of current collectors 31, it is preferable that the thickness of the base 332A in the UD direction be greater than the thickness of the protruding portion 332B in a side view. Alternatively, it is preferable that the thickness of the base 332A in the LR direction be greater than the thickness of the protruding portion 332B in a plan view.

[0082] The protrusion 332B is inserted into the through-hole 60Y. The position of the tip 332BX of the protrusion 332B can be selected arbitrarily. As shown in FIG. 9, the tip 332BX may be located outside the through-hole 60Y. As shown in FIG. 10, the tip 332BX may be located inside the through-hole 60Y. In the third modified example, the lid 360 and the conductive member 332 form a lid unit 360Z. In the third modified example, the lid 360 may be formed of multiple separated parts.

[0083] <2-4. Fourth Modification> As in a fourth modified example shown in FIG. 11, the through-hole 60Y may be omitted from the lid 360 of the third modified example. In the fourth modified example, the protrusion 332B is inserted between the exterior film 50 and the lid 60. In the example shown in FIG. 11, the tip 332BX is located between the exterior film 50 and the lid 360. As shown in FIG. 12, the tip 332BX may be located outside the exterior 40. Note that in the fourth modified example, the lid 360 may be composed of multiple separated parts.

[0084] <2-5. Fifth Modification> In the above embodiment, the lid body 60 and the exterior film 50 are joined via the adhesive film 90, but the lid body 60 and the exterior film 50 may be joined via a resin molded body. The resin molded body covers at least a part of the sealing surface 63 of the lid body 60. When the resin molded body covers the entire sealing surface 63 of the lid body 60, the resin molded body is a frame that surrounds the sealing surface 63 of the lid body 60.

[0085] The resin molded body is made of a resin material. Here, "made of a resin material" means that, when the total amount of materials constituting the resin molded body is 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 resin molded body can contain, in addition to the resin material, materials other than the resin material.

[0086] Specific examples of the resin include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic resin, as well as modified versions of these resins. The resin material may be a mixture of these resins, a copolymer, or a modified version of the 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 resin molded body may be molded by any molding method.

[0087] The resin material contained in the material constituting the resin molded body is preferably an olefin-based random copolymer, more preferably a resin containing a polyolefin skeleton as a main component, even more preferably a polyolefin as a main component, and even more preferably polypropylene as a main component. The polyolefin may be an acid-modified polyolefin. The resin material contained in the material constituting the resin molded body preferably contains multiple types of amide-based lubricants. Furthermore, the resin material contained in the material constituting the resin molded body preferably contains multiple types of amide-based lubricants that further contain unsaturated fatty acid amides in addition to saturated fatty acid amides. The resin material contained in the material constituting the resin molded body may be a polyolefin resin to which a propylene-based elastomer having a melting point higher than 150°C has been added.

[0088] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymer polyesters. Examples of copolymer polyesters include copolymer polyesters whose repeating units are primarily ethylene terephthalate. Specific examples include copolymer polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl dicarboxylate), and polyethylene (terephthalate / decane dicarboxylate). Among these, polybutylene terephthalate is preferred as the resin material from the viewpoint of improving heat resistance and pressure resistance.

[0089] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. Among these, polypropylene is preferred as the resin material because of its excellent heat-sealing properties and electrolyte resistance.

[0090] The resin as the resin material may contain a filler as needed. Specific examples of the filler include glass beads, graphite, glass fiber, and carbon fiber. By containing the filler in the resin as the resin material, the deformation resistance of the resin molded body to temperature changes can be improved.

[0091] The melt mass flow rate of the resin material contained in the material constituting the resin molded body 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.

[0092] <2-6. Sixth 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 Goebel-top pouch or a brick pouch. In the fourth modified example, it is preferable that the electrode terminal be joined to the second surface 62 of the lid body 60. It is preferable that the length of the electrode terminal in the FB direction is such that it is exposed from the portion of the exterior film 50 that protrudes outward beyond the lid body 60.

[0093] <2-7. Seventh Variation> In the above embodiment, the exterior body 40 may not have one of the two lid bodies 60. In this modification, in the FB direction, in the portion of the exterior body 40 where the lid body 60 is omitted, the electrode body 20 is sealed by closing the portion of the exterior film 50 that protrudes outward beyond the electrode body 20. The portion of the exterior film 50 that protrudes outward beyond the electrode body 20 may be folded like a Gabeltop pouch or a brick pouch.

[0094] <2-8. Eighth 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]

[0095] 10: Energy storage device 20: Electrode body 31: Current collector 32, 232, 332: Conductive material 40: Exterior body 50: Exterior film 60, 360: Lid 60X: Recess 60Y: Through hole 61: 1st page 62:Second side 232A, 332A: Base 232B: Hostage Unit 332B: Protrusion 332BX: Pioneer

Claims

1. an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid containing a metal material and sealing the electrode assembly together with the exterior film; a conductive member connected to the lid and the current collector, At least a portion of the conductive member is disposed between the lid body and the electrode body, The lid has a recess that accommodates at least a portion of the conductive member. Energy storage device.

2. An electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid containing a metal material and sealing the electrode assembly together with the exterior film; a conductive member connected to the lid and the current collector, At least a portion of the conductive member is disposed between the lid body and the electrode body, The conductive member is a base portion joined to the lid body; a clamping portion connected to the base and sandwiching the current collector therebetween. Energy storage device.

3. A conductive member used in an electricity storage device, The electricity storage device is an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid body that contains a metal material and seals the electrode body together with the exterior film, the lid has a recess that accommodates at least a portion of the conductive member, At least a portion of the conductive member is disposed between the lid body and the electrode body and is connected to the lid body and the current collector. Conductive material.

4. A conductive member for use in an electricity storage device, comprising: The electricity storage device is an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid body that contains a metal material and seals the electrode body together with the exterior film, at least a portion of the conductive member is disposed between the lid body and the electrode body and is connected to the lid body and the current collector; a base portion joined to the lid body; a clamping portion connected to the base and sandwiching the current collector therebetween. Conductive material.

5. The conductive member according to claim 3 or 4; the lid body joined to the conductive member. Lid unit.

6. A method for manufacturing an electricity storage device, comprising: The electricity storage device is an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid containing a metal material and sealing the electrode assembly together with the exterior film; a conductive member connected to the lid and the current collector, At least a portion of the conductive member is disposed between the lid body and the electrode body, The method for manufacturing the electricity storage device includes: a first connecting step of connecting the current collector and the conductive member; a second connecting step of connecting the conductive member and the lid body. A method for manufacturing an electricity storage device.

7. The first connecting step is performed before the second connecting step. The method for manufacturing the electricity storage device according to claim 6 .

8. an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid that seals the electrode assembly together with the exterior film; a conductive member connected to the lid and the current collector, The lid body is a first surface facing the electrode body; a second surface opposite the first surface; a through hole passing through the first surface and the second surface, The conductive member is a base portion joined to the current collector; a protrusion connected to the base and inserted into the through hole, In a side view or a plan view, the thickness of the base portion is greater than the thickness of the protrusion portion, The tip of the protrusion is located inside the through hole. Energy storage device.

9. A method for manufacturing an electricity storage device, comprising: The electricity storage device is an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid that seals the electrode assembly together with the exterior film; a conductive member connected to the lid and the current collector, The lid body is a first surface facing the electrode body; a second surface opposite the first surface; a through hole passing through the first surface and the second surface, The conductive member is a base portion joined to the current collector; a protrusion connected to the base and inserted into the through hole, In a side view or a plan view, the thickness of the base portion is greater than the thickness of the protrusion portion, The method for manufacturing the electricity storage device includes: a first connecting step of connecting the current collector and the conductive member; a second connecting step of connecting the conductive member and the lid body. A method for manufacturing an electricity storage device.

10. The first connecting step is performed before the second connecting step. The method for manufacturing the electricity storage device according to claim 9 .

11. an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid that seals the electrode assembly together with the exterior film; a conductive member connected to the lid and the current collector, The conductive member is a base portion joined to the current collector; a protrusion connected to the base and inserted between the exterior film and the lid, In a side view or a plan view, the thickness of the base portion is greater than the thickness of the protrusion portion. Energy storage device.

12. A conductive member used in an electricity storage device, The electricity storage device is an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid that seals the electrode body together with the exterior film, The conductive member is a base portion joined to the current collector; a protrusion connected to the base and inserted between the exterior film and the lid, In a side view or a plan view, the thickness of the base portion is greater than the thickness of the protrusion portion. Conductive material.

13. The conductive member according to claim 12; the lid body joined to the conductive member. Lid unit.

14. A method for manufacturing an electricity storage device, comprising: The electricity storage device is an electrode assembly including a current collector; an exterior film that wraps the electrode body; a lid that seals the electrode assembly together with the exterior film; a conductive member connected to the lid and the current collector, The conductive member is a base portion joined to the current collector; a protrusion connected to the base and inserted between the exterior film and the lid, In a side view or a plan view, the thickness of the base portion is greater than the thickness of the protrusion portion, The method for manufacturing the electricity storage device includes: a first connecting step of connecting the current collector and the conductive member; a second connecting step of connecting the conductive member and the lid body. A method for manufacturing an electricity storage device.

15. The first connecting step is performed before the second connecting step. The method for manufacturing the electricity storage device according to claim 14 .

Images