Energy storage device, lid, method for manufacturing an energy storage device

Abstract

The present invention provides an energy storage device capable of outputting a suitable electric current, a cover used in this energy storage device, and a method for manufacturing the energy storage device. [Solution] The energy storage device comprises an electrode body, an outer film enclosing the electrode body, and a lid body comprising a conductive material and sealing the electrode body together with the outer film. The lid body has a lid body and a protrusion integrally formed with the lid body and projecting from the lid body in the direction opposite to the electrode body. The protrusion is hollow.

Description

Technical Field

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[0001] The present invention relates to a power storage device, a lid body, and a method for manufacturing 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 including a current collector, an exterior body that seals the electrode body, and an electrode terminal connected to the current collector. The exterior body includes an exterior film that wraps the electrode body and a lid body joined to the exterior film. The electrode terminal is inserted into a through hole formed in the lid body. The end of the current collector is joined to the electrode terminal.

Prior Art Documents

Patent Documents

[0003] [[ID=​​​​​​​​​​​​​​​​​​​​​​​A first aspect of the present invention relates to an energy storage device comprising an electrode body, an outer film enclosing the electrode body, and a lid body comprising a conductive material and sealing the electrode body together with the outer film, wherein the lid body has a lid body and a protrusion integrally formed with the lid body and projecting from the lid body in a direction opposite to the electrode body, and the protrusion is hollow.

[0007] A second aspect of the present invention relates to an energy storage device comprising an electrode body, an outer film enclosing the electrode body, and a lid body comprising a conductive material and sealing the electrode body together with the outer film, wherein the lid body has a lid body and a protrusion integrally formed with the lid body and projecting from the end of the lid body in a direction opposite to that of the electrode body.

[0008] A third aspect of the present invention relates to a power storage device according to the second aspect, wherein the thickness of the portion constituting the protrusion is within the range of 0.1 mm to 4.0 mm.

[0009] A power storage device according to the fourth aspect of the present invention is a power storage device according to the third aspect, wherein the thickness of the portion constituting the lid body is within the range of 0.1 mm to 4.0 mm.

[0010] A fifth aspect of the present invention relates to a power storage device relating to any one of the first to fourth aspects, wherein the lid body has a base and a flange that is connected to the base and joined to the outer film.

[0011] A power storage device according to the sixth aspect of the present invention is a power storage device according to any one of the first to fifth aspects, wherein the protrusion is connected to the edge of the lid body.

[0012] A power storage device according to the seventh aspect of the present invention is a power storage device according to any one of the first to fifth aspects, wherein the protrusion is formed with a gap between it and the edge of the lid body.

[0013] A lid according to the eighth aspect of the present invention is a lid used as an exterior body for an energy storage device, comprising a conductive material, and having a lid body and a protrusion integrally formed with the lid body and protruding from the lid body, wherein the protrusion is hollow.

[0014] A lid according to the ninth aspect of the present invention is a lid used as an exterior body for an energy storage device, comprising a conductive material, and having a lid body and a protrusion integrally formed with the lid body and protruding from the end of the lid body.

[0015] A method for manufacturing an energy storage device according to a tenth aspect of the present invention is a method for manufacturing an energy storage device comprising: an electrode body; an outer film enclosing the electrode body; and a lid body comprising a conductive material and sealing the electrode body together with the outer film. The lid body has a lid body and a protrusion integrally formed with the lid body and projecting from the lid body in the direction opposite to the electrode body, wherein the protrusion is hollow. The method for manufacturing the energy storage device includes the step of positioning the lid body relative to the electrode body.

[0016] A method for manufacturing an energy storage device according to an eleventh aspect of the present invention is a method for manufacturing an energy storage device comprising: an electrode body; an outer film enclosing the electrode body; and a lid body comprising a conductive material and sealing the electrode body together with the outer film. The lid body has a lid body and a protrusion integrally formed with the lid body and projecting from the end of the lid body in a direction opposite to the electrode body. The method for manufacturing the energy storage device includes the step of positioning the lid body relative to the electrode body. [Effects of the Invention]

[0017] According to the present invention, the energy storage device, the cover, and the method for manufacturing the energy storage device, current can be output effectively. [Brief explanation of the drawing]

[0018] [Figure 1A] A perspective view of the energy storage device according to the embodiment. [Figure 1B]A diagram related to a method for measuring the sealing strength of the second sealing portion of the power storage device shown in FIG. 1. [Figure 2] A cross-sectional view showing the layer structure of the exterior film included in the power storage device of FIG. 1. [Figure 3] A view of the exterior film included in the power storage device of FIG. 1 in a spread state. [Figure 4] A perspective view of the back side of the lid included in the power storage device of FIG. 1. [Figure 5] A perspective view of the front side of the lid of FIG. 4. [Figure 6] A cross-sectional view taken along line D6-D6 of FIG. 1A. [Figure 7] A cross-sectional view taken along line D7-D7 of FIG. 1A. [Figure 8] A flowchart showing an example of a method for manufacturing the power storage device of FIG. 1. [Figure 9] A perspective view of the back side of the lid included in the power storage device of the first modified example. [Figure 10] A perspective view of the front side of the lid of FIG. 9. [Figure 11] A cross-sectional view of the lid included in the power storage device of the second modified example. [Figure 12] A perspective view of the front side of the lid included in the power storage device of the third modified example. [Figure 13] A perspective view of the back side of the lid included in the power storage device of the fourth modified example. [Figure 14] A cross-sectional view of the lid included in the power storage device of the fifth modified example. [Figure 15] A cross-sectional view of the lid included in the power storage device of the sixth modified example.

Embodiments for Carrying Out the Invention

[0019] Hereinafter, a power storage device according to an embodiment of the present invention will be described with reference to the drawings. In this specification, a numerical range indicated by "~" means "or more" and "or less". For example, the notation of 2~15 mm means from 2 mm or more to 15 mm or less.

[0020] [Embodiment] <1-1. Configuration of the Power Storage Device> Figure 1A is a schematic plan view showing 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 100B of the energy storage device 10 of Figure 1A. 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 perspective view of the back side of the lid 60 provided on the energy storage device 10 of Figure 1A. Figure 5 is a perspective view of the front side of the lid 60 of Figure 4. Figure 6 is a cross-sectional view along the line D6-D6 in Figure 1A. Figure 7 is a cross-sectional view along the line D7-D7 in Figure 1A. In Figure 1A, the direction of arrow UD indicates the thickness direction of the energy storage device 10, the direction of arrow LR indicates the width direction of the energy storage device 10, and the direction of arrow FB indicates the depth direction of the energy storage device 10. The directions indicated by arrows UDLRFB are common to all subsequent figures.

[0021] 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.

[0022] One end 31 of the current collector 30 (see Figure 7) is connected to the cover 60.

[0023] 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. In this embodiment, the outer film 50 is wrapped around the electrode body 20. The lid 60 is positioned to the side of the electrode body 20 in the FB direction. In another example, the electrode body 20 may be housed inside a cylindrical outer film 50 with openings formed at both ends in the FB direction, and the openings may be closed by the lid 60. In yet another example, the electrode body 20 may be housed inside a cylindrical outer film 50 with openings formed therein, connected to the lid 60, and the openings may be closed by the lid 60.

[0024] For example, one method is to form a housing portion (recess) for housing the electrode body 20 in the outer film 50 through cold forming. However, it is not always easy to form a deep housing portion by such a method. If one attempts to form a deep housing portion (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 the thickness of the electrode body 20. 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 it is necessary to apply high pressure uniformly from the outside surface of the battery in order to exert 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.

[0025] 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.

[0026] The outer film 50 may be composed of a laminate comprising at least a barrier layer 52 and a heat-fusible resin layer 53 in that order. In this laminate, the base layer 51 is a layer provided as needed, with the side of the barrier layer 52 opposite to the heat-fusible resin layer 53 being the outermost layer, and the heat-fusible resin layer 53 being the innermost layer.

[0027] The overall thickness of the outer film 50 can be arbitrarily selected. From the viewpoint of strength, the thickness of the outer film 50 is preferably 50 μm or more. From the viewpoint of moldability or conformability, the thickness of the outer film 50 is preferably 1200 μm or less. The thickness of the outer film 50 is preferably within the range of 50 μm to 1200 μm.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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. In addition, silicon, magnesium, copper, manganese, etc. may be added to the aluminum alloy foil 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. Examples of hard aluminum alloy foils include aluminum alloy foils having compositions specified in JIS H4160:1994 A8021H-H18, JIS H4160:1994 A8079H-H18, JIS H4000:2014 A8021P-H14, or JIS H4000:2014 A8079P-H14. From the viewpoint of improving the mechanical strength of the outer film 50, it is preferable that the aluminum alloy foil is an aluminum alloy foil containing magnesium. In an aluminum alloy foil containing magnesium (100% by mass), the magnesium content is preferably 0.2 to 5.6% by mass, and more preferably 0.2 to 3.0% by mass. Examples of aluminum alloy foils containing magnesium include those having compositions specified in JIS H4000:2017 A5005P-O, JIS H4000:2017 A5050P-O, and JIS H4000:2017 A5052P-O.

[0032] 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.

[0033] Specific examples of austenitic stainless steels that make up stainless steel foil include SUS304, SUS301, and SUS316L, with SUS304 being particularly preferred among these.

[0034] 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, for example, about 5 to 1000 μm. The thickness of the barrier layer 52 is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and particularly preferably about 35 μm or less. 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 ranges for the thickness of the barrier layer 52 include approximately 9.0 to 1000 μm, 9.0 to 1000 μm, 9.0 to 1000 μm, 9.0 to 85 μm, 9.0 to 50 μm, 9.0 to 40 μm, 9.0 to 35 μm, 20 to 85 μm, 20 to 50 μm, 20 to 40 μm, 20 to 35 μm, 25 to 85 μm, 25 to 50 μm, 25 to 40 μm, and 25 to 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] The lid 60 comprises a lid body 70, a protrusion 80, and a covering 90 that covers a part of the lid body 70. The lid 60 can be manufactured, for example, by injection molding the covering 90 onto the lid body 70.

[0043] The lid body 70 and the protrusion 80 are constructed containing a conductive material. "Constructed containing a conductive material" means that, when the total mass of the materials constituting the lid body 70 and the protrusion 80 is considered to be 100% by mass, the content of the conductive 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 materials constituting the lid body 70 and the protrusion 80 may contain materials other than the conductive material in addition to the conductive material. It is preferable that the lid body 70 and the protrusion 80 have the corrosion-resistant coating described in the barrier layer 52.

[0044] The conductive material constituting the lid body 70 and the protrusion 80 is, for example, a metallic material. The metallic material constituting the lid body 70 and the protrusion 80 is, for example, aluminum, aluminum alloy, nickel, copper, or copper alloy. For example, if the electrode body 20 is a lithium-ion battery, the lid body 70 and the protrusion 80 connected to the positive electrode are preferably made of aluminum or an aluminum alloy. The lid body 70 and the protrusion 80 connected to the negative electrode are preferably made of nickel, copper, or a copper alloy. The material constituting the lid body 70 and the protrusion 80 connected to the negative electrode may be copper with nickel plating. The material constituting the lid body 70 and the protrusion 80 may include recycled metallic material. The lid body 70 has a base portion 71 and a flange portion 72.

[0045] The base portion 71 shown in Figures 4 and 5 is, for example, a rectangular plate and has a first surface 71A and a second surface 71B. The first surface 71A faces the outside. The second surface 71B is the surface opposite to the first surface 71A. The second surface 71B faces the electrode body 20. The base portion 71 may be any shape such as a cylinder, prism, rectangular parallelepiped, or cube.

[0046] The flange portion 72 is covered by the covering 90. The flange portion 72 is frame-shaped, rising from the edge of the base portion 71. The flange portion 72 has a first flange portion 72A, a second flange portion 72B, and a third flange portion 72C. The first flange portion 72A constitutes the upper surface of the lid body 70. In a front view of the lid body 70, the first flange portion 72A extends in a first direction (in this embodiment, the LR direction). The second flange portion 72B and the third flange portion 72C connect with the first flange portion 72A and constitute the side surface of the lid body 70. In a front view of the lid body 70, the second flange portion 72B and the third flange 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 flange portion 72D constitutes the lower surface of the lid body 70. The fourth flange portion 72D extends in the first direction (in this embodiment, the L-R direction) in a front view of the lid body 70.

[0047] At least a portion of the surface 72X of the flange portion 72 is covered by the covering 90. In this embodiment, the entire surface 72X of the flange portion 72 is covered by the covering 90. Any part of the lid body 70 is connected to the end 31 of the current collector 30. In the example shown in Figure 7, the second surface 71B of the base portion 71 is connected to the end 31 of the current collector 30.

[0048] The protrusion 80 is an element for outputting current to the outside and is connected to an external device. The protrusion 80 may also be, for example, an element for fixing the energy storage device 10. The protrusion 80 is formed integrally with the lid body 70. That is, this embodiment does not include a configuration in which the lid body 70 and the protrusion 80 are constructed separately and joined by, for example, welding. Since no joining defects occur between the lid body 70 and the protrusion 80 during the manufacturing of the lid 60, the energy storage device 10 can suitably output current to the external device. Furthermore, since the process of joining the lid body 70 and the protrusion 80 is unnecessary, the manufacturing method of the energy storage device 10 can be simplified.

[0049] The protrusion 80 protrudes from the lid body 70 in the direction opposite to the electrode body 20 (hereinafter referred to as the "outward direction"). Preferably, the protrusion 80 protrudes outward from an element of the lid body 70 that faces the electrode body 20, or from an element that indirectly faces the electrode body 20 via any member. In this embodiment, the protrusion 80 protrudes outward from the base 71 of the lid body 70. In a side view of the energy storage device 10, the outward direction can be arbitrarily selected as long as it is the direction opposite to the electrode body 20. In this embodiment, the outward direction coincides with the FB direction in a side view of the energy storage device 10. The outward direction may also be a direction that intersects the FB direction in a side view of the energy storage device 10.

[0050] The protrusion 80 can be arbitrarily selected as long as it protrudes outward from the lid body 70. In this embodiment, the protrusion 80 is a hollow block shape that protrudes outward from the base 71 of the lid body 70. In cross-sectional view, the shape of the protrusion 80 is rectangular. The shape of the tip of the protrusion 80 may be angular, or it may be rounded by R-processing. A space 80A is formed inside the protrusion 80.

[0051] In the UD direction, the position where the protrusion 80 is formed can be arbitrarily selected. In the example shown in Figure 5, the protrusion 80 is formed approximately in the center in the UD direction. The protrusion 80 may be formed closer to the first flange portion 72A in the UD direction, or closer to the fourth flange portion 72D.

[0052] The width of the protrusion 80 in the LR direction can be arbitrarily selected. In the example shown in Figure 5, the protrusion 80 extends from one edge to the other edge of the base 71 in the LR direction. In the LR direction, the protrusion 80 may be formed with a gap between it and at least one of the two edges of the base 71.

[0053] The length of the outward-facing protrusion 80 can be arbitrarily selected. From the viewpoint of easy connection to external equipment, the length of the outward-facing protrusion 80 is preferably 0.5 mm or more, and more preferably 1.0 mm or more. From the viewpoint of making the energy storage device 10 compact, the length of the outward-facing protrusion 80 is preferably 30 mm or less, and more preferably 10 mm or less. The preferred range for the length of the outward-facing protrusion 80 is 0.5 mm to 30 mm, 0.5 mm to 10 mm, 1.0 mm to 30 mm, or 1.0 mm to 10 mm.

[0054] The number of protrusions 80 on a single cover 60 can be arbitrarily selected. In the example shown in Figure 5, etc., a single cover 60 has one protrusion 80. A single cover 60 may have two or more protrusions 80.

[0055] The lid body 70 and the protrusion 80 may be made of the same conductive material, or they may be made of different conductive materials. At least one of the lid body 70 and the protrusion 80 may be made of partially different conductive materials.

[0056] The lid body 70 and the protrusion 80, configured as described above, can be manufactured, for example, by cutting, grinding, electrical discharge machining, laser processing, casting, rolling, sintering, powder metallurgy, 3D printing, press forming, sheet metal processing, or forging. The lid body 70 and the protrusion 80 are not limited to these methods and can be manufactured by any other method.

[0057] The thickness HA of the portion constituting the lid body 70 and the thickness HB of the portion constituting the protrusion 80 (see Figure 7 for both) can be arbitrarily selected. From the viewpoint of easily manufacturing the lid body 70 and the protrusion 80, it is preferable that the thicknesses HA and HB are 0.1 mm or more. On the other hand, if the volume of the lid body 70 and the protrusion 80 is large, when forming the second sealing portion 100B described later, the heat from the heat seal may be absorbed by the lid body 70 and the protrusion 80, which may cause a bonding defect in the second sealing portion 100B. In addition, the time required for the process of forming the second sealing portion 100B will be longer. Furthermore, if the volume of the lid body 70 and the protrusion 80 is large, the gravimetric energy density of the energy storage device 10 itself will be lower. Therefore, from the viewpoint of suitably forming the second sealing portion 100B and from the viewpoint of suppressing a decrease in the gravimetric energy density of the energy storage device 10 itself, the thicknesses HA and HB are preferably 7.0 mm or less, more preferably 4.0 mm or less, more preferably 3.0 mm or less, and still more preferably 2.0 mm or less. The preferred ranges for the thicknesses HA and HB are 0.1 mm to 7.0 mm, 0.1 mm to 4.0 mm, 0.1 mm to 3.0 mm, or 0.1 mm to 2.0 mm. The parts constituting the lid body 70 and the protrusion 80 may have partially different thicknesses. If the thicknesses of the parts constituting the lid body 70 and the protrusion 80 are partially different, then the thicknesses HA and HB are the maximum thicknesses, respectively.

[0058] The covering 90 shown in Figures 4, 5, and 6 has a lid sealing portion 91. The lid sealing portion 91 is heat-sealed to the heat-fusible resin layer 53 of the outer film 50. The lid sealing portion 91 and the outer film 50 may be joined by any method other than heat sealing, such as welding. Specific welding methods include, for example, laser welding or ultrasonic welding, or any other method. The lid sealing portion 91 includes a first sealing surface 91A, a second sealing surface 91B, a third sealing surface 91C, and a fourth sealing surface 91D. The first sealing surface 91A constitutes the upper surface of the lid 60. The first sealing surface 91A is formed on the first flange portion 72A. In a front view of the lid 60, the first sealing surface 91A extends in a first direction (in this embodiment, the L-R direction). The second sealing surface 91B and the third sealing surface 91C connect to the first sealing surface 91A and constitute the side surface of the lid 60. The second sealing surface 91B is formed on the second flange portion 72B. The third sealing surface 91C is formed on the third flange portion 73C. The second sealing surface 91B and the third sealing surface 91C extend in a second direction (in this embodiment, the UD direction) that intersects the first direction in a front view of the lid 60. In this embodiment, the first direction and the second direction are orthogonal in a front view of the lid 60. The first direction and the second direction do not have to be orthogonal in a front view of the lid 60. The fourth sealing surface 91D constitutes the lower surface of the lid 60. The fourth sealing surface 91D extends in a first direction (in this embodiment, the LR direction) in a front view of the lid 60. The fourth sealing surface 91D is formed on the fourth flange portion 72D.

[0059] The lid seal portion 91 further includes boundaries 92, 93, 94, and 95. Boundary 92 is the boundary between the first seal surface 91A and the second seal surface 91B. Boundary 93 is the boundary between the first seal surface 91A and the third seal surface 91C. Boundary 94 is the boundary between the fourth seal surface 91D and the second seal surface 91B. Boundary 95 is the boundary between the fourth seal surface 91D and the third seal surface 91C. The shape of boundaries 92 to 95 may be angular, or it may be rounded by R-processing. In this embodiment, boundaries 92 to 95 are angular.

[0060] The coating 90 is made of a resin material. Here, "made of a resin material" means that when the total mass of the materials constituting the coating 90 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 90 may contain materials other than resin materials in addition to the resin material.

[0061] 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-sealable resin such as polyester or polyolefin, and more preferably polyolefin. When the resin material is a resin, the coating 90 may be molded by any molding method.

[0062] The resin material included in the material constituting the coating 90 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 90 preferably contains multiple types of amide lubricants. Furthermore, the resin material included in the material constituting the coating 90 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 90 may be a polyolefin resin to which a propylene-based elastomer with a melting point higher than 150°C has been added.

[0063] 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.

[0064] 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.

[0065] 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 90 to temperature changes can be improved.

[0066] The melt mass flow rate of the resin material contained in the material constituting the coating 90 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 according to JIS K7210-1:2014. The measurement temperature for the melt mass flow rate is 230°C.

[0067] The lid 60 may be joined to the outer film 50 via an adhesive film instead of the covering 90. The adhesive film can be arbitrarily selected as long as it is a film that can adhere the outer film 50 and the lid 60. Preferably, the adhesive film is a laminated film having at least a heat-fusible resin layer, a heat-resistant substrate layer, and a heat-fusible resin layer in this order. The specifications for the heat-fusible resin layer of the adhesive film can be the same as those for the heat-fusible resin layer 53. The materials constituting the heat-fusible resin layers on both sides of the adhesive film may be the same material or different materials, and are appropriately selected in accordance with the materials constituting the heat-fusible resin layer 53 of the outer film 50 and the materials constituting the lid 60. Preferably, the material constituting the heat-fusible resin layer on the side of the adhesive film that is adhered to the lid 60 is an acid-modified polyolefin resin graft-modified with an acid such as maleic anhydride. It is preferable that the heat-sealable resin layer of the adhesive film that is bonded to the outer film 50 is made of the same material as the material that constitutes the heat-sealable resin layer 53 of the outer film 50.

[0068] The heat-resistant base layer can be any film made of a heat-resistant resin. For example, unstretched or stretched films of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polymethylpentene (registered trademark), polyacetal cyclic polyolefin, polyethylene, polypropylene, etc. can be used. Polyethylene terephthalate is particularly preferred because it is inexpensive and strong.

[0069] The adhesive film preferably has adhesive properties. When forming the second sealing portion 100B, described later, with the adhesive film positioned between the outer film 50 and the lid 60, the position of the adhesive film relative to the lid 60 and the outer film 50 is less likely to shift. Adhesion can be imparted to the adhesive film by incorporating an adhesive-imparting resin into the heat-fusible resin layer of the adhesive film. Examples of adhesive-imparting resins include amorphous polyolefins. Examples of amorphous polyolefins include amorphous polypropylene, or copolymers of amorphous propylene and other α-olefins. The content of the adhesive-imparting resin relative to the base material constituting the heat-fusible resin is preferably 10 to 20% by weight or less.

[0070] 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 91 of the lid 60 has a certain width in the FB direction so as to allow for suitable heat sealing of the lid seal portion 91 of the lid 60 and the outer casing film 50 when forming the second sealing portion 100B described later. The minimum width of the lid seal portion 91 of the lid 60 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum width of the lid seal portion 91 of the lid 60 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum width of the lid seal portion 91 of the lid 60 may be 20 mm or more. The preferred width ranges for the lid seal portion 91 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 form in which the lid 60 is composed solely of film as defined by the JIS (Japanese Industrial Standards) [Packaging Terminology] standard. The width of the lid seal portion 91 of the lid 60 may vary depending on the part. If the width of the lid seal portion 91 of the lid 60 varies depending on the part, the width of the lid seal portion 91 of the lid 60 is the width of the widest part.

[0071] In this embodiment, with the outer film 50 wrapped around the electrode body 20, the first sealing portion 100A is formed by heat sealing the opposing surfaces (heat-fusible resin layers 53) of the outer film 50 together.

[0072] The first sealing portion 100A 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 100A extends in the longitudinal direction of the outer body 40. The position in the outer body 40 where the first sealing portion 100A is formed can be arbitrarily selected. In this embodiment, it is preferable that the base 70X of the first sealing portion 100A 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 100AX of the first sealing portion 100A may be located on any surface of the outer body 40. In this embodiment, in a plan view, the first sealing portion 100A protrudes outward from the electrode body 20. The first sealing portion 100A may be folded toward the second surface 42 of the outer body 40, or it may be folded toward the first surface 41.

[0073] In this embodiment, the second sealing portion 100B (lid sealing portion 100B) is formed by heat sealing the heat-fusible resin layer 53 of the outer film 50 and the lid sealing portion 91 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 91 of the lid 60 may be referred to as the sealing strength (joint strength) of the second sealing portion 100B. The sealing strength of the second sealing portion 100B 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 91, that is, the portion of the lid sealing portion 91 extending in the LR (width) direction in Figure 1A.

[0074] The seal strength of the second sealing section 100B 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 100B. 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 100B 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 100B 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 100B is the sealing strength of the long side portion of the lid sealing portion 91 of the multiple parts.

[0075] 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 100B 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 100B 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 several years (less than 10 years). When the seal strength of the second sealing portion 100B 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 more than 10 years. The seal strength of the second sealing portion 100B is preferably 300 N / 15 mm or less. The preferred range for the seal strength of the second sealing portion 100B 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.

[0076] In this embodiment, it is preferable that the lid 60 has a protruding portion 96 that protrudes from the lid sealing portion 91 so that a gap is less likely to form between the outer film 50 and the lid 60. The protruding portion 96 may be formed integrally with the covering 90, or it may be formed separately from the covering 90 and joined to the covering 90. In this embodiment, the protruding portion 96 is formed integrally with the covering 90. The position in the lid sealing portion 91 where the protruding portion 96 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 100AX of the first sealing portion 100A and the lid 60. In particular, when the base 100AX of the first sealing portion 100A is located at the boundary 92 to boundary 95 of the lid 60, the resin filling performance between the base 100AX of the first sealing portion 100A and the lid 60 tends to decrease. Therefore, it is preferable that the protrusion 96 be formed in the lid sealing portion 91 at the location where the base 100AX of the first sealing portion 100A is located. In this embodiment, the base 100AX of the first sealing portion 100A is located at the boundary 92 of the lid 60. Therefore, it is preferable that the protrusion 96 be formed at the boundary 92 in the lid sealing portion 91. In this embodiment, the first sealing portion 100A is sealed with the protrusion 96 sandwiched between them. The protrusion 96 may be formed on at least one of the first sealing surface 100AA, the second sealing surface 100AB, the third sealing surface 100AC, the fourth sealing surface 100AD, the boundary 93, the boundary 94, and the boundary 95.

[0077] The shape of the protrusion 96 can be arbitrarily selected. In this embodiment, the shape of the protrusion 96 is plate-like. The thickness of the protrusion 96 can be arbitrarily selected. In this embodiment, the thickness of the protrusion 96 decreases as it moves away from the boundary 92. In other words, the protrusion 96 has a tapered shape as it moves away from the boundary 92. The thickness of the protrusion 96 may be constant, or it may increase as it moves away from the boundary 92.

[0078] The direction in which the protrusion 96 extends can be arbitrarily selected. In this embodiment, the protrusion 96 extends along a first direction (the LR direction in this embodiment). The protrusion 96 may also extend along a second direction (the UD direction in this embodiment). In a front view of the lid 60, the protrusion 96 may extend in a third direction that intersects the first direction (the LR direction in this embodiment) and the second direction (the UD direction in this embodiment).

[0079] The length of the protrusion 96 can be arbitrarily selected within a range less than or equal to the length of the first sealing portion 100A. For example, the length of the protrusion 96 may be substantially equal to the length of the first sealing portion 100A, or it may be 30% to 50% of the length of the first sealing portion 100A.

[0080] <1-2. Method for manufacturing energy storage devices> Figure 8 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, a fourth step, a fifth step, and a sixth step. Steps 1 to 6 are carried out, for example, by a manufacturing apparatus for the energy storage device 10. At least a portion of steps 1 to 6 may be carried out by an operator. Note that steps 1 to 6 are names that are conveniently defined for each step of the method for manufacturing the energy storage device 10 and do not necessarily mean the order of the steps. The order of steps 1 to 6 can be changed arbitrarily, as long as it is not technically contradictory.

[0081] In the first step of step S11, the manufacturing apparatus manufactures the lid 60.

[0082] The second step, S12, is performed after the first step. In the second step, the manufacturing apparatus places a pair of covers 60 to the side of the electrode body 20 in the FB direction.

[0083] The third step, S13, is performed after the second step. In the second step, the manufacturing apparatus joins the current collector 30 and the cover 60.

[0084] Step S14, the fourth step, is performed after the third step. In the fourth 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. Alternatively, the electrode body 20 may be housed inside a cylindrical outer film 50 with openings formed at both ends in the FB direction, and after joining the current collector 30 and the cover 60, the openings may be closed with the cover 60. In yet another example, the electrode body 20, connected to the cover 60, may be housed inside a cylindrical outer film 50 with openings formed at both ends in the FB direction, and the openings may be closed with the cover 60.

[0085] Step S15, the fifth step, is performed after the fourth step. In the fifth step, the manufacturing apparatus forms the second sealing portion 110B by heat sealing the outer film 50 and the lid 60.

[0086] Step S16, the sixth step, is performed before or after step 5. In step 6, the manufacturing apparatus forms the first sealing portion 100A by heat sealing the heat-sealable resin layer 53 of the outer film 50, including the first edge 50A, and the heat-sealable resin layer 53 of the outer film 50, including the second edge 50B, while tension is applied to the outer film 50, while restricting the movement of the electrode body 20 and the lid body 60.

[0087] <1-3. Function and Effects of Energy Storage Devices> Since the lid body 70 and the protrusion 80 of the energy storage device 10 are integrally formed, poor bonding between the lid body 70 and the protrusion 80 does not occur. Therefore, the energy storage device 10 can output current to external devices effectively.

[0088] [2. Variant] The embodiments described above are illustrative of possible forms of the energy storage device, cover, and method for manufacturing the energy storage device according to the present invention, and are not intended to limit their forms. The energy storage device, cover, and method for manufacturing the 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 a part of the configuration of the embodiment is replaced, modified, or omitted, or a form in which a new configuration is added to the embodiment. 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.

[0089] <2-1. First variation> In the above embodiment, the shape of the protrusion 80 can be changed. Figure 9 is a perspective view of the rear side of the lid 160 of the first modified energy storage device 10. Figure 10 is a perspective view of the front side of the lid 160 of Figure 9. Note that the covering 90 is omitted in Figures 9 and 10.

[0090] The lid 160 has a lid body 170 and a protrusion 180 integrally formed with the lid body 170. The lid body 170 has the same configuration as the lid body 70. The protrusion 180 may be formed with a gap between it and one edge and the other edge of the base 71 in at least one of the LR direction and the UD direction. A space 180A is formed inside the protrusion 180. That is, the protrusion 180 is hollow. The lid body 170 and the protrusion 180 can also be manufactured by the manufacturing method illustrated in the embodiment. The protrusion 180 can be any shape, such as cylindrical, as long as it is hollow.

[0091] <2-2. Second variation> The shape of the protrusion 80 in cross-sectional view can be arbitrarily selected. Figure 11 is a cross-sectional view of the lid 260 of the second modified energy storage device 10. Note that the covering 90 is omitted in Figure 11. The lid 260 has a lid body 270 and a protrusion 280 integrally formed with the lid body 270. The protrusion 280 may be triangular in cross-sectional view. A space 280A is formed inside the protrusion 280. The lid body 270 and the protrusion 280 can be manufactured, for example, by the manufacturing method exemplified in the embodiment.

[0092] <2-3. Third Variation> In the above embodiment, at least a portion of the flange portion 72 of the cover 60 may be omitted. Figure 12 is a front perspective view of the cover 360 of the third modified energy storage device 10. Note that the covering 90 is omitted in Figure 12.

[0093] The lid 360 has a lid body 370 and a protrusion 380 integrally formed with the lid body 370. The lid body 370 has a shape in which the second flange portion 72B and the third flange portion 72C are omitted from the lid body 70 of the embodiment. Openings 370Y are formed at both ends of the lid body 370 in the LR direction.

[0094] The protrusion 380 is, for example, a hollow block shape, with a space 380A formed inside. Openings 380Y are formed at both ends of the protrusion 380 in the LR direction. The lid body 370 and the protrusion 380 can be manufactured by the manufacturing method illustrated in the embodiment. To facilitate joining the lid body 360 to the outer film 50, it is preferable that a resin molded product for joining with the outer film 50 is positioned so as to fill at least a portion of the openings 370Y and 380Y. The resin molded product may be insert-molded into the lid body 370, for example. Note that the lid body 370 may omit the first flange portion 72A and the fourth flange portion 72D in addition to the second flange portion 72B and the third flange portion 72C.

[0095] <2-4. Fourth Variation> In the above embodiment, the position of the protrusion 80 in the UD direction can be arbitrarily changed. Figure 13 is a front perspective view of the lid body 470 of the fourth modified energy storage device 10. Note that the covering 90 is omitted in Figure 13.

[0096] The lid 460 has a lid body 470 and a protrusion 480 integrally formed with the lid body 470. The lid body 470 has a shape in which the second flange portion 72B, the third flange portion 72C, and the fourth flange portion 72D are omitted from the lid body 70 of the embodiment.

[0097] The protrusion 480 is, for example, a solid plate. The protrusion 480 protrudes outward from the lower end of the base 71 in the UD direction. The lid body 470 and the protrusion 480 can be manufactured by the manufacturing method illustrated in the embodiment.

[0098] <2-5. Fifth variation> In the fourth modified example, the protrusion 480 may project outward from the upper end of the base 71 in the UD direction. Figure 14 is a cross-sectional view of the cover 560 of the fifth modified energy storage device, which is a further modification of the fourth modified energy storage device 10. Note that the covering 90 is omitted in Figure 14.

[0099] The lid 560 has a lid body 570 and a protrusion 580 integrally formed with the lid body 570. The protrusion 580 projects outward from the upper end of the base 71 in the UD direction. The protrusion 580 is, for example, a hollow block. In cross-sectional view, the shape of the protrusion 580 is rectangular. In cross-sectional view, the shape of the protrusion 580 may be a circle, an ellipse, a triangle, or a polygon. A space 580A is formed inside the protrusion 580. The lid body 570 and the protrusion 580 can be manufactured by the manufacturing methods illustrated in the embodiments.

[0100] <2-6. Sixth Variation> In the fifth modified example, the shape of the protrusion 580 can be changed. Figure 15 is a cross-sectional view of the cover 660 of the sixth modified energy storage device, which is a further modified version of the fifth modified energy storage device 10. Note that the covering 90 is omitted in Figure 15.

[0101] The lid 660 has a lid body 670 and a projection 680 integrally formed with the lid body 670. The projection 680 protrudes outward from the upper end of the base 71 in the UD direction. The projection 680 is a solid plate. The projection 680 has a first portion 681, a second portion 682, and a third portion 683. The first portion 681 is connected to the base 71 and extends, for example, in the FB direction. The second portion 682 is connected to the first portion 681 and extends, for example, in the UD direction. The third portion 683 is connected to the second portion 682 and extends, for example, in the FB direction. The lid body 670 and the projection 680 can be manufactured by the manufacturing methods illustrated in the embodiments.

[0102] <2-7. Seventh 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. In the eighth modification, the length of the outward-facing protrusion 80 is preferably such that it is exposed from the portion of the outer film 50 that extends outward beyond the lids 60.

[0103] <2-8. Eighth 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.

[0104] <2-9. Ninth 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]

[0105] 10: Energy storage devices 20: Electrode body 30: Current collector 40: Exterior 50: Exterior film 60: Lid 70: Lid body 72: Flange section 80: Convex part 160: Lid 170: Lid body 180: Convex part 260: Lid 270: Lid body 280: Convex part 360: Lid 370: Lid body 380: Convex part 460: Lid 470: Lid body 480: Convex part 560: Lid 570: Lid body 580: Convex part 660: Lid 670: Lid body 680: Convex part 760: Lid 770: Lid body 780: Convex part

Claims

1. Electrode body and The electrode body is enclosed by an outer casing, The exterior body is, The outer film enclosing the electrode body, It comprises a lid made of a conductive material that seals the electrode body together with the outer film, The aforementioned cover is The lid body that constitutes the end face of the exterior body, It is integrally formed with the lid body and has a protrusion that extends from at least one of the upper edge and lower edge of the lid body in the stacking direction of the electrode body, The aforementioned lid body is The first side faces the outside, It has a second surface which is opposite to the first surface and faces the electrode body, The aforementioned upper and lower edges are edges that define the second surface, The aforementioned protrusion projects in the direction opposite to the electrode body in the direction in which the electrode body and the lid body are aligned, and is formed extending from one opposing edge of the lid body to the other. Energy storage device.

2. The thickness of the portion constituting the aforementioned protrusion is within the range of 0.1 mm to 4.0 mm. The energy storage device according to claim 1.

3. The thickness of the portion constituting the lid body is within the range of 0.1 mm to 4.0 mm. The energy storage device according to claim 2.

4. The aforementioned lid body is The base and, It has a flange portion that is connected to the base and joined to the exterior film. The energy storage device according to any one of claims 1 to 3.

5. A lid used as an outer casing for an energy storage device, It is composed of a conductive material, The lid body that constitutes the end face of the exterior body, The energy storage device has a protrusion that extends from at least one of the upper and lower edges of the lid body in the stacking direction of the electrode bodies, The aforementioned lid body is The first side faces the outside, It has a second surface which is opposite to the first surface and faces the electrode body, The aforementioned upper and lower edges are edges that define the second surface, The aforementioned protrusion projects in the direction opposite to the electrode body in the direction in which the electrode body and the lid body are aligned, and is formed extending from one opposing edge of the lid body to the other. Cover.

6. A method for manufacturing an energy storage device, The aforementioned energy storage device is Electrode body and The electrode body is enclosed by an outer casing, The exterior body is, The outer film enclosing the electrode body, It comprises a lid made of a conductive material that seals the electrode body together with the outer film, The aforementioned cover is The lid body that constitutes the end face of the exterior body, It is integrally formed with the lid body and has a protrusion that extends from at least one of the upper edge and lower edge of the lid body in the stacking direction of the electrode body, The aforementioned lid body is The first side faces the outside, It has a second surface which is opposite to the first surface and faces the electrode body, The aforementioned upper and lower edges are edges that define the second surface, The aforementioned protrusions project in the direction opposite to the electrode body in the direction in which the electrode body and the lid body are aligned, and are formed extending from one opposing edge of the lid body to the other. The method for manufacturing the aforementioned energy storage device is as follows: This includes the step of placing the cover on the electrode body. A method for manufacturing energy storage devices.

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