Power storage device, cover body, fixing tool, method for manufacturing power storage device, and

Abstract

This electricity storage device is provided with an electrode body and an exterior body for sealing the electrode body. The exterior body includes: an exterior film covering the electrode body so as to form an opening; and a cover body disposed in the opening portion. The cover body has a first surface facing the electrode body, a second surface opposite to the first surface, and a protruding portion protruding from the second surface.

Description

Technical Field

[0001] The present invention relates to an electricity storage device, a cover, a fixing tool, a method for manufacturing the electricity storage device, and a transportation tool. Background Art

[0002] Patent Document 1 discloses an example of an electrical storage device. The electrical storage device includes an electrode assembly and an exterior body that seals the electrode assembly. The exterior body includes an exterior film that covers the electrode assembly to form an opening, and a cover disposed over the opening. The exterior film and the cover are bonded to each other.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2022-123686. Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the manufacturing process of the aforementioned power storage device, an intermediate body is produced, in which lids are placed on both ends of the electrode body. The intermediate body is then moved to the work site of the next manufacturing process. Therefore, as the intermediate body moves, the position of the lids relative to the electrode body may shift.

[0008] An object of the present invention is to provide an electricity storage device with a high positional accuracy of a cover relative to an electrode body, a cover for the electricity storage device, a fixing tool and a transport tool used when manufacturing or using the electricity storage device, and a method for manufacturing the electricity storage device.

[0009] Technical means to solve the problem

[0010] The first aspect of the present invention provides a storage device comprising an electrode body and an outer casing for sealing the electrode body, the outer casing comprising: an outer casing film covering the electrode body in a manner forming an opening; and a cover body arranged at the opening, the cover body having: a first surface facing the electrode body; a second surface opposite to the first surface; and at least one of a protrusion protruding from the second surface and a recessed portion recessed from the second surface toward the first surface.

[0011] According to a second aspect of the present invention, in the power storage device according to the first aspect, the cover includes a main body having the first surface and the second surface, and the protrusion includes a fixing member joined to the main body.

[0012] According to a third aspect of the present invention, in the power storage device according to the first aspect, the cover includes a main body having the first surface and the second surface, the main body having a thick portion protruding from the second surface, and holes are formed in the thick portion and the main body.

[0013] An electricity storage device according to a fourth aspect of the present invention is the electricity storage device according to the first aspect, wherein the protrusion has a breakable portion.

[0014] A fifth aspect of the present invention is a fixing tool used in manufacturing or using the power storage device according to any one of the first to fourth aspects, comprising a cover fixing portion fixed to at least one of the protruding portion and the recessed portion.

[0015] A cover according to a sixth aspect of the present invention is a cover for a power storage device according to any one of the first to fourth aspects, comprising: a first surface; a second surface opposite to the first surface; and at least one of a protrusion protruding from the second surface and a recessed portion recessed from the second surface toward the first surface.

[0016] A seventh aspect of the present invention is a method for manufacturing a storage device, comprising an electrode body and an outer casing for sealing the electrode body, wherein the outer casing comprises: an outer casing film covering the electrode body in a manner forming an opening; and a cover for sealing the opening, the cover having: a first surface facing the electrode body; a second surface opposite to the first surface; and at least one of a protrusion protruding from the second surface and a recessed portion recessed from the second surface toward the first surface, the method for manufacturing the storage device comprising: a process of fixing the position of the cover relative to the electrode body by fixing a tool to at least one of the protrusion and the recess of the cover arranged on the side of the electrode body.

[0017] A conveyance tool according to an eighth aspect of the present invention is a conveyance tool for an electrode assembly, including: at least a pair of plates sandwiching the electrode assembly; and a connecting portion connecting the pair of plates.

[0018] A transportation tool according to a ninth aspect of the present invention is the transportation tool according to the eighth aspect, further comprising a handle attached to at least one of the pair of plates.

[0019] Effects of the Invention

[0020] The electricity storage device, the cover, the fixing tool, the method for manufacturing the electricity storage device, and the transport tool according to the present invention can contribute to improving the positional accuracy of the cover relative to the electrode assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A It is a plan view schematically showing the power storage device according to the embodiment.

[0022] Figure 1B It's about Figure 1A A diagram illustrating a method for measuring the sealing strength of a second sealing portion of a power storage device.

[0023] Figure 2Yes Figure 1A sectional view showing an example of the layer structure of an exterior film included in a power storage device.

[0024] Figure 3 yes Figure 1A A three-dimensional view of a cover body included in the power storage device.

[0025] Figure 4 yes Figure 1A FIG. 1 is a diagram showing an expanded state of an exterior film included in a power storage device.

[0026] Figure 5 yes Figure 3 A cross-sectional view of the cover body.

[0027] Figure 6 is Figure 1A A perspective view showing a state where an intermediate product is placed on a fixing tool used in a manufacturing process of an electricity storage device.

[0028] Figure 7 Yes Figure 1A A flowchart of an example of a manufacturing process of an electricity storage device.

[0029] Figure 8 It's about Figure 7 Figure 2 of the second process.

[0030] Figure 9 It's about Figure 7 Figure 3 shows the third process.

[0031] Figure 10 It's about Figure 7 Another diagram of the third process.

[0032] Figure 11 It's about Figure 7 Another diagram of the third process.

[0033] Figure 12 It means in Figure 7 Graph showing an example of the relationship between strain and stress acting on the exterior film in the third step.

[0034] Figure 13 It's about Figure 7 Figure 4 shows the fourth process.

[0035] Figure 14 It's about Figure 7 Figure 5 of the fifth process.

[0036] Figure 15 Yes Figure 7 A flowchart of an example of the fifth step.

[0037] Figure 16 It's about Figure 7 Another diagram of the fifth process.

[0038] Figure 17 It's about Figure 7 Figure 6 of the sixth process.

[0039] Figure 18 It's about Figure 7 Figures of the eighth and ninth steps.

[0040] Figure 19 is Figure 1A A side view of a state where the power storage device is mounted on a transport vehicle.

[0041] Figure 20 yes Figure 19 Top view of .

[0042] Figure 21 It is a perspective view of a cover body included in a power storage device according to a modification.

[0043] Figure 22 It is a perspective view of a cover body included in a power storage device according to another modified example.

[0044] Figure 23 It is a side view of a power storage device according to still another modification.

[0045] Figure 24 is fixed Figure 22 A three-dimensional view of a fixing tool for a cover body.

[0046] Figure 25 It is a top view of a power storage device according to a modified example.

[0047] Figure 26 It's about Figure 7 A process diagram of a modified example of the third process.

[0048] Figure 27 It's about Figure 7 A diagram of a process of a modified example of the fifth process.

[0049] Figure 28 It's about Figure 7 The diagram of another modified example of the fifth step shows the state of the sealing strip at the initial position.

[0050] Figure 29 Yes Figure 28 Figure 1 shows the state of the sealing strip in the reference position.

[0051] Figure 30 It's about Figure 7 A diagram of a process of yet another modified example of the fifth process.

[0052] Figure 31 Yes Figure 1AA flowchart of a modified example of the manufacturing process of the power storage device.

[0053] Figure 32 It's about Figure 31 The diagram of the thirty-second step. DETAILED DESCRIPTION

[0054] Hereinafter, an electric storage device according to one embodiment of the present invention will be described with reference to the accompanying drawings. In this specification, a numerical range indicated by "to" means "above" or "below." For example, "2 to 15 mm" means "above 2 mm and below 15 mm."

[0055] [1. Implementation Method]

[0056] <1-1. Structure of Power Storage Device>

[0057] Figure 1A It is a plan view schematically showing the power storage device 10 according to the first embodiment. Figure 1B This is a diagram illustrating a method for measuring the sealing strength of the second sealing portion 80 of the power storage device 10 . Figure 2 Yes Figure 1A 1 is a cross-sectional view showing a layer structure of an exterior film 50 included in the power storage device 10 . Figure 3 yes Figure 1A 1 is a perspective view of a cover 60 included in the power storage device 10. Figure 4 yes Figure 1A FIG. 1 is a diagram showing a state in which the outer film 50 included in the power storage device 10 is unfolded. Figure 5 yes Figure 3 sectional view of the cover body 60. Figure 6 1 is a perspective view of a state where an intermediate product is placed on a fixing tool 100 used in the manufacturing process of the power storage device 10. Figure 1A , arrow UD indicates the thickness direction of the power storage device 10, arrow LR indicates the width direction of the power storage device 10, and arrow FB indicates the depth direction of the power storage device 10. The directions indicated by arrows UD, LR, and FB are common to the following figures.

[0058] The power storage device 10 includes an electrode body 20, an electrode terminal 30, and an outer body 40. The electrode body 20 includes, for example, electrodes (positive and negative electrodes) and a separator that constitute a power storage component such as a lithium-ion battery, a capacitor, an all-solid battery, a semi-solid battery, a pseudo-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-zinc oxide battery, a metal-air battery, a multivalent cation battery, or a capacitor. In this embodiment, the shape of the electrode body 20 is roughly rectangular. Here, "roughly rectangular" includes not only a complete rectangular parallelepiped but also a three-dimensional shape that can be regarded as a rectangular parallelepiped by modifying the shape of a portion of the outer surface. The shape of the electrode body 20 can be, for example, a cylinder or a polygonal prism.

[0059] In this embodiment, the power storage device 10 includes two electrode terminals 30. The electrode terminal 30 is a metal terminal used for inputting and outputting electric power in the electrode body 20. One end of the electrode terminal 30 is electrically connected to the electrode (positive electrode or negative electrode) contained in the electrode body 20. The other end of the electrode terminal 30 protrudes outward from the end edge of the outer casing 40, for example. In addition, the electrode terminal 30 only needs to be able to input and output electric power to and from the electrode body 20, and, for example, it does not need to protrude from the outer casing 40. In the case where the cover body 60 described later is made of metal, for example, the cover body 60 sometimes also has the function of the electrode terminal 30. In this case, the cover body 60 having the function of the electrode terminal may or may not protrude from the outer casing 40.

[0060] The metal material constituting the electrode terminal 30 is, for example, aluminum, nickel, or copper. For example, in the case of a lithium-ion battery, the electrode terminal 30 connected to the positive electrode is typically made of aluminum, while the electrode terminal 30 connected to the negative electrode is typically made of copper, nickel, or the like. Furthermore, the outermost layer of the electrode body 20 does not necessarily have to be an electrode; for example, it may also be a protective tape or a separator.

[0061] The outer casing 40 seals the electrode body 20. The outer casing 40 includes an outer film 50 and a lid 60. The outer film 50 covers the electrode body 20 so as to have an opening 40A. In this embodiment, the outer film 50 is wound around the electrode body 20 so as to have an opening 40A. The lid 60 is arranged at the opening 40A. Alternatively, the electrode body 20 may be housed within the outer film 50, which is cylindrically formed so as to have an opening 40A, and the opening 40A may be sealed by the lid 60.

[0062] From the perspective of good bonding with the cover 60, it is preferable to bond an adhesive film (not shown) to the electrode terminal 30. The adhesive film can be arbitrarily selected as long as it can bond the electrode terminal 30 made of metal to the cover 60 made of resin. The adhesive film can be made of, for example, a polyolefin resin such as a polyethylene resin or a polypropylene resin, a cyclic polyolefin resin, or an acid-modified polyolefin resin obtained by grafting these polyolefin resins with an acid such as maleic anhydride. The adhesive film can be a single layer or a film of two or more layers of these materials. In this embodiment, the adhesive film is bonded to substantially the entire portion of the electrode terminal 30 covered by the cover 60.

[0063] For example, there is a method of forming a housing portion (recess) for housing the electrode body 20 in the outer film 50 by cold forming. However, it is not necessarily easy to form a deep housing portion by such a method. If you want to form the housing portion (recess) deeply by cold forming (for example, a forming depth of 15 mm), there is a possibility of pinholes or cracks in the outer film 50, which increases the possibility of reduced battery performance. On the other hand, the outer body 40 seals the electrode body 20 by winding 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. In addition, in order to reduce the ineffective area between the electrode body 20 and the outer film 50 to increase the volume energy density of the power storage device 10, it is preferred that the outer film 50 is wound in a manner in contact with the outer surface of the electrode body 20. In addition, in an all-solid-state battery, from the perspective of applying high pressure uniformly to the outer surface of the battery in order to exert battery performance, it is also necessary to eliminate the space between the electrode body 20 and the outer film 50. Therefore, it is preferred that the outer film 50 is wound in a manner that contacts the outer surface of the electrode body 20.

[0064] like Figure 2 As shown, the exterior film 50 is, for example, a stack (laminated film) comprising a base layer 51, a barrier layer 52, and a heat-fusible resin layer 53 in this order. Furthermore, the exterior film 50 need not include all of these layers; for example, the barrier layer 52 may not be included. Specifically, the exterior film 50 may be made of a flexible and easily bendable material; for example, it may be made of a resin film. Furthermore, the exterior film 50 is preferably heat-sealable. The innermost and outermost layers of the exterior film 50 may be heat-fusible resin layers 53. In this case, the exterior film 50 may cover the electrode body 20 and the lid 60 by bonding the outermost and innermost layers.

[0065] The base layer 51 included in the exterior film 50 is used to impart heat resistance to the exterior film 50 and to suppress the formation of pinholes that may occur during processing or distribution. The base layer 51 is composed, for example, of at least one of a stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one of the stretched polyester resin layer and the stretched polyamide resin layer in the base layer 51, the barrier layer 52 can be protected during processing of the exterior film 50, thereby suppressing breakage of the exterior film 50. Furthermore, to increase 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, to provide excellent puncture strength and 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. Alternatively, the base layer 51 may be composed of both a stretched polyester resin layer and a stretched polyamide resin layer. From the viewpoint of film strength, the thickness of the base material layer 51 is, for example, preferably 5 to 300 μm, and more preferably 5 to 150 μm.

[0066] The barrier layer 52 is a layer that at least inhibits moisture intrusion. The barrier layer 52 is bonded to the substrate layer 51 via, for example, an adhesive layer 54. Examples of the barrier layer 52 include metal foil, vapor-deposited films, and resin layers having barrier properties. 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 polyvinylidene chloride, polymers based on chlorotrifluoroethylene (CTFE), polymers based on tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers based on fluoroalkyl units, such as fluororesins and ethylene-vinyl alcohol copolymers. Furthermore, 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 also be a multi-layered layer. The barrier layer 52 preferably includes a layer composed 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 preferably contains at least one of aluminum alloy foil and stainless steel foil.

[0067] In the barrier layer 52, the layer composed of the above-mentioned metal material may also contain recycled materials of the metal material. As recycled materials of the metal material, for example, recycled materials of aluminum alloy, stainless steel, titanium steel, or steel plate can be cited. These recycled materials can be obtained by known methods respectively. Recycled materials of 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 only of recycled materials, or may be composed of a mixture of recycled materials and virgin materials (virgin materials). Among them, recycled materials of metal materials refer to metal materials that are recycled, separated, refined, etc. from various products used in the so-called market and waste from the manufacturing process to become reusable. In addition, virgin materials of metal materials refer to new metal materials refined from natural resources (raw materials) of metals, and are not recycled materials.

[0068] To improve the formability and conformability of the exterior film 50, the aluminum alloy foil is preferably a soft aluminum alloy foil, such as one made from an annealed aluminum alloy. To further improve formability and conformability, an aluminum alloy foil containing iron is preferred. In an aluminum alloy foil containing iron (100% by mass), the iron content is preferably 0.1 to 9.0% by mass, more preferably 0.5 to 2.0% by mass. An iron content of 0.1% or greater can provide an exterior film 50 with even better formability. An iron content of 9.0% or less can provide an exterior film 50 with even greater flexibility. Examples of soft aluminum alloy foil include aluminum alloy foil having the composition specified in JIS H4160:1994 A8021H-O, JIS H4160:1994 A8079H-O, JIS H4000:2014 A8021P-O, or JIS H4000:2014 A8079P-O. Silicon, magnesium, copper, manganese, etc. may also be added as needed. Softening can be achieved through annealing or other treatments. To enhance the mechanical strength of the exterior film 50, the aluminum alloy foil is more preferably a hard aluminum alloy foil, such as one made of a work-hardened aluminum alloy. Examples of the hard aluminum alloy foil include aluminum alloy foil having a composition specified in JIS H4160: 1994 A8021H-H18, JIS H4160: 1994 A8079H-H18, JIS H4000: 2014 A8021P-H14, or JIS H4000: 2014 A8079P-H14.

[0069] Examples of the stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation-hardened stainless steel foils. In order to provide an exterior film 50 having excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0070] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS 304, SUS 301, and SUS 316 L. Among them, SUS 304 is particularly preferred.

[0071] In the case of a metal foil, the thickness of the barrier layer 52 is sufficient as long as it at least functions as a barrier layer to inhibit moisture intrusion, and can be, for example, approximately 9 to 200 μm. The thickness of the barrier layer 52 is preferably approximately 85 μm or less, more preferably approximately 50 μm or less, even more preferably approximately 40 μm or less, and particularly preferably approximately 35 μm or less. Furthermore, the thickness of the barrier layer 52 is preferably approximately 10 μm or greater, more preferably approximately 20 μm or greater, and even more preferably approximately 25 μm or greater. Preferred ranges for the thickness of the barrier layer 52 include approximately 10 to 85 μm, approximately 10 to 50 μm, approximately 10 to 40 μm, approximately 10 to 35 μm, approximately 20 to 85 μm, approximately 20 to 50 μm, approximately 20 to 40 μm, approximately 20 to 35 μm, approximately 25 to 85 μm, approximately 25 to 50 μm, approximately 25 to 40 μm, and approximately 25 to 35 μm. When the barrier layer 52 is made of aluminum alloy foil, the above range is particularly preferred. In addition, 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. In addition, it 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. The preferred range is 35 to 200 μm. The outer film 50 has a high formability, which facilitates deep drawing and can contribute to a higher capacity of the power storage device. In addition, since the rigidity of the outer film 50 is improved, the outer film 50 can be easily wound around the electrode body 20 when it is wound around the electrode body 20. Furthermore, while increasing the capacity of an electricity storage device increases its weight, increasing the rigidity of the exterior film 50 can contribute to improved sealing performance of the electricity storage device. Furthermore, particularly when the barrier layer 52 is formed of stainless steel foil, the thickness of the stainless steel foil is preferably approximately 60 μm or less, more preferably approximately 50 μm or less, even more preferably approximately 40 μm or less, even more preferably approximately 30 μm or less, and particularly preferably approximately 25 μm or less. Furthermore, the thickness of the stainless steel foil is preferably approximately 10 μm or greater, and more preferably approximately 15 μm or greater.Preferred ranges of 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.

[0072] Furthermore, when the barrier layer 52 is aluminum foil, it is preferably coated with a corrosion-resistant film on at least the surface opposite the base layer 51 to prevent dissolution and corrosion. The barrier layer 52 may have a corrosion-resistant film on both surfaces. Here, a corrosion-resistant film refers to a thin film imparting corrosion resistance (e.g., acid resistance, alkali resistance, etc.) to the barrier layer 52 by undergoing an anti-corrosion treatment such as a hot water conversion treatment such as boehmite treatment, a chemical conversion treatment, anodizing, plating with nickel or chromium, or coating with a coating agent. Specifically, a corrosion-resistant film includes a film that improves the acid resistance of the barrier layer 52 (acid-resistant film) or a film that improves the alkali resistance of the barrier layer 52 (alkali-resistant film). The corrosion-resistant film can be formed using a single treatment or a combination of two or more. Furthermore, the film may be formed using not only a single layer but also multiple layers. Furthermore, hot water conversion and anodizing are treatments in which a treatment agent dissolves the surface of the metal foil to form a metal compound with excellent corrosion resistance. In addition, these treatments may also be included in the definition of chemical conversion treatment. In addition, when the barrier layer 52 has a corrosion-resistant film, it is regarded as the barrier layer 52 including the corrosion-resistant film.

[0073] The corrosion-resistant coating has the following effects: it prevents delamination between the barrier layer 52 (for example, aluminum alloy foil) and the base layer 51 during the forming or winding of the exterior film 50, prevents hydrogen fluoride generated by the reaction between the electrolyte and moisture from dissolving and corroding the surface of the barrier layer 52, and particularly prevents aluminum oxide present on the surface of the barrier layer 52 from dissolving and corroding when the barrier layer 52 is an aluminum alloy foil, improves the adhesion (wettability) of the surface of the barrier layer 52, prevents delamination between the base layer 51 and the barrier layer 52 during heat sealing, and prevents delamination between the base layer 51 and the barrier layer 52 during forming.

[0074] The heat-fusible resin layer 53 is bonded to the barrier layer 52 via, for example, an adhesive layer 55. The heat-fusible resin layer 53 included in the exterior film 50 is a layer that imparts heat-sealing sealability to the exterior film 50. Examples of the heat-fusible resin layer 53 include resin films composed 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 perspective of sealability and strength, the thickness of the heat-fusible resin layer 53 is preferably 20 to 300 μm, and more preferably 40 to 150 μm.

[0075] The exterior film 50 preferably includes one or more layers having a buffering function (hereinafter referred to as "buffer layers") located outside the thermally fusible resin layer 53, and more preferably located outside the barrier layer 52. The buffer layer may be laminated outside the base layer 51, or the base layer 51 may also function as a buffer layer. If the exterior film 50 includes multiple buffer layers, the multiple buffer layers may be adjacent to each other or laminated with the base layer 51 or the barrier layer 52 interposed therebetween.

[0076] The material constituting the buffer layer can be arbitrarily selected from materials having buffering properties. Examples of materials having buffering properties are rubber, non-woven fabric, or foam sheet. Examples of rubber are natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably about 20 to 90. The material constituting the non-woven fabric is preferably a material having excellent heat resistance. In the case where the buffer layer is composed of a non-woven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and more preferably 1000 μm. In the case where the buffer layer is composed of a non-woven fabric, the upper limit of the thickness of the buffer layer is preferably 5000 μm, and more preferably 3000 μm. The preferred range of the thickness of the buffer layer is 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. The most preferred thickness range of the buffer layer is 1000 μm to 3000 μm.

[0077] When the cushioning layer is made of rubber, the lower limit of the cushioning layer thickness is preferably 0.5 mm. When the cushioning layer is made of rubber, the upper limit of the cushioning layer thickness is preferably 10 mm, more preferably 5 mm, and even more preferably 2 mm. When the cushioning layer is made of rubber, the preferred ranges of the cushioning layer thickness are 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0078] When the exterior film 50 includes a buffer layer, the buffer layer functions as a shock absorber, thereby preventing the exterior film 50 from being damaged by an impact when the power storage device 10 is dropped or by handling during the manufacture of the power storage device 10 .

[0079] Figure 3 The illustrated cover 60 is, for example, a rectangular parallelepiped and is a resin molded article made of a resin material. Alternatively, the cover 60 may be a metal molded article. The material comprising the cover 60 may include at least two or more of a metal oxide, a carbon material, and a rubber material. Alternatively, the cover 60 may include a metal oxide, a carbon material, and a rubber material.

[0080] The cover 60 is preferably composed of a resin material. Here, "composed of a resin material" means that, when the total mass of the material constituting the cover 60 is taken as 100 mass%, the resin material content is 50 mass% or greater, preferably 80 mass% or greater, more preferably 90 mass% or greater, and even more preferably 95 mass% or greater. In other words, the material constituting the cover 60 may contain materials other than resin.

[0081] Specific examples of resins include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic resin, as well as modified forms of these resins. Furthermore, the resin material may be a mixture of these resins, a copolymer, or a modified form of a copolymer. The resin material is preferably a heat-fusible resin such as polyester or polyolefin, with polyolefin being more preferred. When the resin material is a resin, the cover 60 may be formed using any molding method.

[0082] Specific examples of polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyesters. Copolyesters include those having ethylene terephthalate as a main repeating unit. Specific examples include polyester copolymers composed mainly of ethylene terephthalate and ethylene isophthalate (hereinafter referred to as poly(ethylene terephthalate / isophthalate)), poly(ethylene terephthalate / adipate), poly(ethylene terephthalate / sodium sulfoisophthalate), poly(ethylene terephthalate / sodium isophthalate), poly(ethylene terephthalate / phenyl dicarboxylate), and poly(ethylene terephthalate / sebacyl carboxylate). Among these, polybutylene terephthalate is a preferred resin material from the perspective of improving heat resistance and pressure resistance.

[0083] 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 terpolymers of ethylene, butene, and propylene. The polyolefin resin in the case of a copolymer may be a block copolymer or a random copolymer. Among these, polypropylene is preferred due to its excellent thermal sealability and electrolyte resistance.

[0084] The resin material may contain fillers as needed. Specific examples of fillers include glass beads, graphite, glass fibers, and carbon fibers. By including such fillers in the resin material, the deformation resistance of the cover 60 to temperature changes can be improved.

[0085] The melt flow rate of the resin material included in the material constituting the cover 60 is preferably within the range of 1 g / 10 min to 80 g / 10 min, more preferably within the range of 5 g / 10 min to 60 g / 10 min. The melt flow rate is measured in accordance with JIS K7210-1:2014.

[0086] The cover 60 may also be constructed from a conductive material. "Containing a conductive material" means that, when the total mass of the material constituting the cover 60 is taken as 100%, the conductive material content is 50% by mass or greater, preferably 80% by mass or greater, more preferably 90% by mass or greater, and even more preferably 95% by mass or greater. In other words, the material constituting the cover 60 may contain materials other than the conductive material.

[0087] The conductive material constituting the cover 60 is, for example, a metal material. The metal material constituting the cover 60 is, for example, aluminum, an aluminum alloy, nickel, copper, or a copper alloy. For example, in the case where the electrode body 20 is a lithium-ion battery, the cover 60 connected to the positive electrode is preferably made of aluminum or an aluminum alloy. The cover 60 connected to the negative electrode is preferably made of nickel, copper, or a copper alloy. The material constituting the cover 60 connected to the negative electrode may also be copper plated with nickel. The material constituting the cover 60 may also include recycled materials of metal materials. In the case where the cover 60 is composed of a conductive material, the cover 60 also has the function of the electrode terminal 30. Since the electrode terminal 30 can be omitted from the power storage device 10, the structure of the power storage device 10 can be simplified.

[0088] In the case where the cover body 60 is composed of a conductive material, the cover body 60 may be bonded to the outer film 50 via an adhesive film. The adhesive film may be arbitrarily selected as long as it is a film that can bond the outer film 50 to the cover body 60. The adhesive film is preferably a laminated film having at least a heat-melting resin layer, a heat-resistant base material layer, and a heat-melting resin layer in this order. The specifications for the heat-melting resin layer 53 can be applied to the specifications of the heat-melting resin layer of the adhesive film. The materials constituting the heat-melting resin layers on both sides of the adhesive film may be the same material or different materials, and may be appropriately selected according to the material constituting the heat-melting resin layer 53 of the outer film 50 and the material constituting the cover body 60. The material constituting the heat-melting resin layer on the side of the adhesive film bonded to the cover body 60 is preferably an acid-modified polyolefin resin obtained by graft modification using an acid such as maleic anhydride. The heat-adhesive resin layer on the side of the adhesive film that is bonded to the exterior film 50 is preferably made of the same material as that constituting the heat-adhesive resin layer 53 of the exterior film 50 .

[0089] The heat-resistant substrate layer may be any film made of a heat-resistant resin, and examples thereof include unstretched or stretched films of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polymethylpentene (registered trademark), polyacetal, cyclic polyolefin, polyethylene, and polypropylene. Of these, polyethylene terephthalate is particularly preferred due to its low cost and high strength.

[0090] The adhesive film preferably has tackiness. When the second sealing portion 80 described later is formed with the adhesive film disposed between the exterior film 50 and the cover 60, the position of the adhesive film relative to the cover 60 and the exterior film 50 is not easily displaced. By making the heat-fusible resin layer of the adhesive film contain a tackifying resin, it is possible to impart tackiness to the adhesive film. Examples of the tackifying resin include amorphous polyolefins. Examples of amorphous polyolefins include amorphous polypropylene or copolymers of amorphous propylene and other α-olefins. The content of the tackifying resin relative to the base material constituting the heat-fusible resin is preferably 10 to 20% by weight or less.

[0091] The lid 60 includes a main body 60A. The main body 60A includes 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 the first surface 61. The sealing surface 63 is continuous with the first surface 61 and the second surface 62 and is bonded to the heat-fusible resin layer 53 of the exterior film 50.

[0092] 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 cover 60. The first sealing surface 63A extends in a first direction (in this embodiment, the LR direction) in a front view of the cover 60. The second sealing surface 63B and the third sealing surface 63C are connected to the first sealing surface 63A and constitute the side surface of the cover 60. In a front view of the cover 60, the second sealing surface 63B and the third sealing surface 63C extend in a second direction (in this embodiment, the UD direction) that intersects the first direction. In this embodiment, when the cover 60 is viewed from the front, the first direction and the second direction are orthogonal. The first and second directions do not necessarily need to be orthogonal in a front view of the cover 60. The fourth sealing surface 63D constitutes the lower surface of the cover 60. The fourth sealing surface 63D extends in the first direction (in this embodiment, the LR direction) in a front view of the cover 60.

[0093] When the main body 60A is plate-shaped, even when the power storage device 10 is stacked, the main body 60A preferably has a certain degree of thickness to suppress deformation of the outer body 40. From another perspective, when the main body 60A is plate-shaped, in order to effectively heat-seal the sealing surface 63 of the main body 60A and the outer film 50 when forming the second sealing portion 80 described later, the sealing surface 63 of the main body 60A preferably has a certain degree of thickness. The minimum thickness of the main body 60A is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum thickness of the main body 60A is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum thickness of the main body 60A may also be 20 mm or more. The preferred thickness ranges for the material constituting the main body 60A 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 main body 60A is described as plate-shaped, the material constituting the main body 60A does not include films specified in the JIS (Japanese Industrial Standards) "Packaging Terms" standard. Furthermore, the thickness of the main body 60A may vary depending on the location of the main body 60A. If the thickness of the main body 60A varies depending on the location, the thickness of the main body 60A is the thickness of the thickest portion.

[0094] The main body 60A also includes boundaries 64, 65, 66, and 67. Boundary 64 is the boundary between the first sealing surface 63A and the second sealing surface 63B. Boundary 65 is the boundary between the first sealing surface 63A and the third sealing surface 63C. Boundary 66 is the boundary between the fourth sealing surface 63D and the second sealing surface 63B. Boundary 67 is the boundary between the fourth sealing surface 63D and the third sealing surface 63C. The shapes of boundaries 64 to 67 can be corners or have rounded corners by performing R processing. In this embodiment, boundaries 64 to 67 are corners.

[0095] Examples of materials constituting the main body 60A include polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins, fluorine resins, and polypropylene resins, cyclic polyolefin resins, and acid-modified polyolefin resins obtained by grafting these polyolefin resins with an acid such as maleic anhydride. To ensure proper heat sealing between the main body 60A and the exterior film 50, the main material of the main body 60A and the material of the heat-fusible resin layer 53 of the exterior film 50 are preferably the same. In this embodiment, the main materials constituting the main body 60A and the heat-fusible resin layer 53 are, for example, polyolefin resins such as polyethylene resins and polypropylene resins, or acid-modified polyolefin resins obtained by grafting these polyolefin resins with an acid such as maleic anhydride. The main material refers to, for example, a material that accounts for 50% or more of the materials included in the component.

[0096] In this embodiment, a through hole 60X is formed in the main body 60A, into which the electrode terminal 30 is inserted. The through hole 60X penetrates the first surface 61 and the second surface 62. When the electrode body 20 is covered by the outer film 50, the electrode terminal 30 protrudes to the outside of the outer body 40 through the through hole 60X formed in the main body 60A. The small gap between the through hole 60X of the main body 60A and the electrode terminal 30 is filled with resin, for example. In addition, in the power storage device 10, the position where the electrode terminal 30 protrudes to the outside can be selected arbitrarily. For example, the electrode terminal 30 may also protrude to the outside from a hole formed on any of the six surfaces of the outer body 40. In this case, the small gap between the outer body 40 and the electrode terminal 30 is filled with resin or film, for example. In another example, the electrode terminal 30 may also protrude to the outside of the outer body 40 from between the sealing surface 63 of the main body 60A and the outer film 50. In this case, the through-hole 60X need not be formed in the cover 60. In the power storage device 10, the main body 60A and the electrode terminal 30 are provided separately, but the main body 60A and the electrode terminal 30 may be formed integrally. Furthermore, if the electrode terminal 30 does not protrude from the edge of the exterior body 40, the through-hole 60X need not be formed in the main body 60A.

[0097] During the manufacturing process of the electrical storage device 10, an intermediate body is produced, in which the cover 60 is placed at both ends of the electrode body 20. The intermediate body is then moved to the work site of the next process. In this embodiment, a fixing tool 100 is attached to the intermediate body during this movement, which is used to fix the position of the cover 60 relative to the electrode body 20. Therefore, the cover 60 has a protrusion 60B in addition to the main body 60A, to which the fixing tool 100 is attached.

[0098] The protrusion 60B protrudes from the second surface 62 of the main body 60A. The number of protrusions 60B included in the cover 60 can be arbitrarily selected. In the present embodiment, the cover 60 includes two protrusions 60B. The cover 60 may also include one or more than three protrusions 60B. The position at which the protrusion 60B protrudes on the second surface 62 can be arbitrarily selected. As in the present embodiment, when the main body 60A is formed with a through hole 60X, in order to prevent the electrode terminal 30 from interfering with the protrusion 60B, the protrusion 60B is preferably formed at a position away from the through hole 60X.

[0099] The specific structure of the protrusion 60B can be arbitrarily selected as long as it is a structure that the fixing tool 100 can fix. In this embodiment, the protrusion 60B is a fixing component embedded in the main body 60A. The fixing component is, for example, an embedded nut. A female thread or a male thread is formed on the embedded nut. Figure 5 As shown, the end portion of the protrusion 60B opposite to the end portion protruding from the second surface 62 is embedded in the interior of the main body 60A. That is, the protrusion 60B does not penetrate the main body 60A. In the case where the embedded nut is made of a metal material, in order to improve the bonding strength with the cover body 60, it is preferred to subject the embedded nut to a corrosion-resistant treatment such as chromate treatment. The load-bearing capacity of one embedded nut is preferably greater than the value obtained by dividing the weight of the storage device 10 by the total number of protrusions 60B. In addition, the fixing component may also have at least one of a suction cup, a magnet, a protrusion, a magic tape (registered trademark), a spring pin and a clamp so that the fixing tool 100 can be fixed.

[0100] like Figure 6 As shown, the fixing tool 100 includes a cover fixing portion 110 for fixing the cover 60 and a placement portion 120 for placing the electrode body 20. The cover fixing portion 110 and the placement portion 120 are connected by any means. The cover fixing portion 110 and the placement portion 120 may also be formed integrally.

[0101] The cover fixing portion 110 has a support portion 111 for supporting the cover body 60 and a wall portion 112 rising from the support portion 111. The wall portion 112 is formed with holes 112X corresponding to the number of protrusions 60B. The cover body 60 is fixed to the cover fixing portion 110 by engaging the thread formed on the embedded nut constituting the protrusion 60B with the male thread or the female thread. In addition, when the thread formed on the embedded nut constituting the protrusion 60B is a female thread, the female thread engages with the male thread inserted into the hole 112X. In the case where the thread formed on the embedded nut constituting the protrusion 60B is a male thread, the male thread engages with the female thread formed on the nut or the socket. The female thread can be arranged entirely outside the hole 112X, or at least a portion can be inserted into the hole 112X. The wall portion 112 is also formed with a slit 112Y for inserting the electrode terminal 30. The slit 112Y passes through the wall portion 112. Alternatively, the wall portion 112 may be constructed to include multiple divided sections, with the multiple sections clamping the electrode terminal 30. If the cover 60 also functions as an electrode terminal, the slit 112Y may be omitted. The mounting portion 120 is, for example, plate-shaped and supports substantially the entire electrode assembly 20. Furthermore, the fixing tool 100 can also be attached to a finished electrical storage device 10. In other words, the fixing tool 100 can also be used during operation of the electrical storage device 10.

[0102] In this embodiment, with the exterior film 50 wound around the electrode assembly 20 with the opening 40A, the facing surfaces (thermo-fusible resin layers 53 ) of the exterior film 50 are heat-sealed to form the first sealing portion 70 .

[0103] The first sealing portion 70 is formed by Figure 4 The outer film 50 shown is formed by heat-sealing a portion including the first edge 50A and a portion including the second edge 50B. The first sealing portion 70 extends in the longitudinal direction (FB direction) of the outer body 40. In the outer body 40, the position where the first sealing portion 70 is formed can be selected arbitrarily. In the present embodiment, the root 70X of the first sealing portion 70 is preferably located on the edge 43 of the boundary between the first surface 41 and the second surface 42 of the outer body 40. The area of ​​the first surface 41 is larger than the area of ​​the second surface 42. The root 70X of the first sealing portion 70 may also be located on any surface of the outer body 40. In the present embodiment, the first sealing portion 70 extends outward compared to the electrode body 20 when viewed from above. The first sealing portion 70 may be folded toward the second surface 42 of the outer body 40, or may be folded toward the first surface 41.

[0104] In this embodiment, the second sealing portion 80 is formed by heat-sealing the heat-fusible resin layer 53 of the exterior film 50 and the sealing surface 63 of the cover 60. Hereinafter, the sealing strength between the heat-fusible resin layer 53 of the exterior film 50 and the sealing surface 63 of the cover 60 may be referred to as the sealing strength of the second sealing portion 80. In addition, the sealing strength of the second sealing portion 80 is the sealing strength of the long side portion of the sealing surface 63, i.e., Figure 1A The sealing strength between the heat-fusible resin layer 53 and the lid 60 on the sealing surface 63 extending in the LR (width) direction is measured.

[0105] The sealing strength of the second sealing portion 80 is measured as follows. First, a cut is made in the portion of the first surface 41 of the outer body 40 in the outer film 50 to form three strip-shaped parts 41X, 41Y, and 41Z arranged in the LR direction (see FIG. Figure 1B (Double-dashed line). The width of the three strips 41X, 41Y, and 41Z in the LR direction is 15 mm. The ends of the strips 41X, 41Y, and 41Z are joined to the cover 60 in the second sealing portion 80. The length of the cover 60 in the LR direction is 45 mm or longer. Next, the sealing strength of each strip 41X, 41Y, and 41Z is measured by pulling the ends of the strips 41X, 41Y, and 41Z opposite to the ends joined to the cover 60 upward in the UD direction (in the direction opposite to the first surface 41B). In this embodiment, the sealing strength of the second sealing portion 80 is the average of the sealing strengths of the strips 41X, 41Y, and 41Z. If the length of the cover 60 in the LR direction is less than 45 mm, three strips of any width X mm less than 15 mm are formed and the sealing strength of the three strips is measured using the same method as when the length of the cover 60 in the LR direction is 45 mm or longer. The obtained seal strengths are divided by an arbitrary width X mm, and then multiplied by 15 to convert the seal strengths of the three strip-shaped components to a width of 15 mm. The seal strength of the second sealing portion 80 is the average of the seal strengths of the three strip-shaped components converted to a width of 15 mm. Furthermore, when the cover 60 is divided into multiple sections containing long and short sides, the seal strength of the second sealing portion 80 is the seal strength of the long side of the multiple sealing surfaces 63.

[0106] From the perspective of properly maintaining the state in which the electrode body 20 is sealed by the outer casing 40, the sealing strength of the second sealing portion 80 is preferably 40 N / 15 mm or greater, more preferably 50 N / 15 mm or greater, further preferably 60 N / 15 mm or greater, further preferably 70 N / 15 mm or greater, and even further preferably 85 N / 15 mm or greater. When the sealing strength of the second sealing portion 80 is 40 N / 15 mm or greater, the state in which the electrode body 20 is sealed by the outer casing 40 can be properly maintained even if the power storage device 10 is used for, for example, several years (less than 10 years). When the sealing strength of the second sealing portion 80 is 85 N / 15 mm or greater, the state in which the electrode body 20 is sealed by the outer casing 40 can be properly maintained even if the power storage device 10 is used for, for example, more than 10 years. The sealing strength of the second sealing portion 80 is preferably 300 N / 15 mm or less. The sealing strength of the second sealing portion 80 preferably ranges from 40 N / 15 mm to 300 N / 15 mm, 50 N / 15 mm to 300 N / 15 mm, 60 N / 15 mm to 300 N / 15 mm, 70 N / 15 mm to 300 N / 15 mm, or 85 N / 15 mm to 300 N / 15 mm.

[0107] <1-2. Method for Manufacturing Power Storage Device>

[0108] Figure 7 This is a flowchart illustrating an example of a method for manufacturing the power storage device 10. The method for manufacturing the power storage device 10 includes, for example, a first step, a second step, a third step, a fourth step, a fifth step, a sixth step, a seventh step, an eighth step, and a ninth step. The first through ninth steps are performed, for example, by a device for manufacturing the power storage device 10. The following names of the first through ninth steps are given for convenience only and do not necessarily indicate the order of the steps.

[0109] In the first process (cap unit manufacturing process) of step S11 , the manufacturing apparatus manufactures a pair of cap units 60Z in which the cap body 60 and the electrode terminal 30 are bonded together.

[0110] The second step (connection step) of step S12 is performed after the first step. In the second step, the manufacturing apparatus arranges a pair of cover units 60Z at both ends of the electrode body 20 to electrically connect the electrode terminal 30 to the electrode body 20 .

[0111] Figure 8This is a diagram about the second process. In the second process, the manufacturing device positions a pair of cover units 60Z relative to the electrode body 20 by means of a positioning device (not shown). In the second process, for example, the long side PA and the short side PB of the electrode body 20 when viewed from above are used as a reference to position a pair of cover units 60Z relative to the electrode body 20. As the positioning device, for example, a well-known image processing device can be used. In this embodiment, as the image processing device, an image processing device manufactured by KEYENCE Co., Ltd. is used. The detection method of the image processing device is edge position measurement using transmission inspection. The resolution of the image processing device is 0.01 mm. In this embodiment, an image processing device is used to detect the short side PB by transmission inspection, and the correction amount with respect to the reference side on the opposite side is calculated based on the position information. After the second process is completed, a fixing tool 100 (refer to Figure 6 The intermediate product is transported to the work site of the third step with the fixing tool 100 attached thereto.

[0112] The third step (winding step) of step S13 is performed after the second step. In the third step, the fixing tool 100 is removed from the intermediate body. In the third step, the manufacturing device winds the outer film 50 around the electrode body 20 and the cover 60. In the third step, the outer film 50 is positioned relative to the intermediate body based on the long side PA and short side PB set in the second step. In addition, in the third step, in order to form the extension portion 90 (see Figure 16 ), an exterior film 50 having a larger area than that of the finished power storage device 10 is used.

[0113] Figures 9 to 11 This is a diagram relating to the third process. In the third process, the manufacturing device places the electrode body 20 on the outer film 50. By placing the electrode body 20 on the outer film 50, one of the pair of first surfaces 41 of the outer body 40 is formed. The manufacturing device presses at least one of the electrode body 20 and the cover body 60 placed on the outer film 50 against the outer film 50, while winding the outer film 50 around the electrode body 20 and the cover body 60. In this embodiment, the electrode body 20 and the cover body 60 are pressed against the outer film 50 by, for example, a rod-shaped pressing member 130. Since the third process can be performed in a state where the electrode body 20 and the cover body 60 are placed on a pedestal on which the outer film 50 is placed, the outer film 50 can be easily wound around the electrode body 20 and the cover body 60. In addition, it is preferred that the rod-shaped pressing member 130 is in contact with substantially the entire upper surface of the electrode body 20 and the cover body 60.

[0114] like Figure 10As shown, in the third step, the outer film 50 is bent so as to form one of the pair of second surfaces 42 of the outer body 40. After the outer film 50 is bent, the portion of the outer film 50 corresponding to the corner of the lid 60 is pressed against the lid 60 by, for example, a rod-shaped pressing member 140. The pressing member 140 may be shaped so as to press the entire second surface 42 against the electrode body 20 and the lid 60, or may be shaped, for example, L-shaped, corresponding to the corner between the first surface 41 and the second surface 42.

[0115] Then, if Figure 11 As shown, in the third step, the exterior film 50 is bent so as to form the other second surface 42 of the pair of second surfaces 42 of the exterior body 40. After the exterior film 50 is bent, the portion of the exterior film 50 corresponding to the corner of the cover body 60 is pressed against the cover body 60 by, for example, a rod-shaped pressing member 150.

[0116] Next, the pressing member 130 (see Figure 9 ) After being separated from the electrode body 20 , the exterior film 50 is bent so as to form the other first surface 41 of the pair of first surfaces 41 of the exterior body 40 .

[0117] In addition, in order to suppress the generation of wrinkles and slack in the outer film 50 during the winding process, it is preferable that the manufacturing apparatus separates the outer film 50 from the extension portion 90 (see FIG. Figure 16 ) The corresponding part is stretched in any direction with a specified strength.

[0118] Figure 12 This is an example of a graph showing the relationship between strain and stress acting on the exterior film 50. If the strain and stress acting on the exterior film 50 are too small, the exterior film 50 wound around the electrode assembly 20 may sag. In this embodiment, to suppress sag in the exterior film 50, the specified strength is determined such that the strain acting on the exterior film 50 is at least a lower limit value XA (%), and the stress acting on the exterior film 50 is at least a lower limit value YA (MPa).

[0119] On the other hand, if the strain and stress acting on the exterior film 50 are excessively large, wrinkles may form in the exterior film 50 wound around the electrode assembly 20. In this embodiment, to suppress wrinkles in the exterior film 50, the specified strength is determined so that the strain acting on the exterior film 50 is below an upper limit value XB (%) and the stress acting on the exterior film 50 is below an upper limit value YB (MPa).

[0120] Specifically, in this embodiment, during the winding process, the portion of the exterior film 50 corresponding to the extension 90 is stretched at a predetermined strength. Therefore, the strain acting on the exterior film 50 is within a range of a lower limit value XA (%) to an upper limit value XB (%), and the stress acting on the exterior film 50 is within a range of a lower limit value YA (MPa) to an upper limit value YB (MPa). An example of the lower limit value XA is 0.10 (%). An example of the upper limit value XB is 0.43 (%). An example of the lower limit value YA is 1.1 (MPa). An example of the upper limit value YB is 13.2 (MPa).

[0121] The fourth process of step S14 is performed after the third process. Figure 13 As shown, in the fourth step, the manufacturing apparatus forms a first FB direction sealing portion 71 having an unsealed portion 71Z in the center of the portion forming the extension portion 90 in the exterior film 50. The first FB direction sealing portion 71 extends in the FB direction. Figure 13 The hatched portion in represents an example of a region where the first FB direction sealing portion 71 is formed.

[0122] The fifth process (sealing process) of step S15 is performed before or after the fourth process. In addition, the fifth process can also be performed in parallel with the third process. Figure 14 As shown, in the fourth step, the manufacturing apparatus forms the second sealing portion 80. In the fifth step, the second sealing portion 80 is preferably formed while the fixing tool 100 is attached to the cover 60. Figure 14 The shaded portion shown shows an example of a region where the second sealing portion 80 is formed.

[0123] like Figure 15 As shown, the fifth step preferably includes a first sealing step of step S21 and a resealing step of step S22 performed after the first sealing step.

[0124] In the first sealing step, from the viewpoint of properly bonding the boundaries 64 to 67 of the cover 60 to the exterior film 50, it is preferable that the manufacturing apparatus is configured to seal the cover 60 (see FIG. Figure 16 ) and the cover 60 move relative to the other while forming the second seal 80. In this embodiment, the sealing device 160 forms the second seal 80 while moving relative to the cover 60. In this embodiment, an ultrasonic sealing device or a welding machine is used as the sealing device 160. The sealing device 160 may be, for example, a heat sealing device using a roller or a heat sealing device using a sealing strip shorter than any of the sealing surfaces 63A to 63D of the cover 60.

[0125] Figure 16It is a diagram about the first sealing process. In the first sealing process, the sealing device 160 preferably joins the sealing surfaces adjacent to the outer film 50 in sequence. The sealing device 160 moves, for example, in a manner that passes through the first sealing surface 63A, the third sealing surface 63C, the fourth sealing surface 63D, and the second sealing surface 63B in sequence. The sealing device 160 may also move in the order of the second sealing surface 63B, the fourth sealing surface 63D, the third sealing surface 63C, and the first sealing surface 63A. In the first sealing process, for example, the second sealing portion 80 may also be formed by two sealing devices 160. For example, one sealing device 160 may move in a manner that starts from the boundary 67 and passes through the third sealing surface 63C and the first sealing surface 63A in the order. The other sealing device 160 may move in a manner that starts from the boundary 67 and passes through the fourth sealing surface 63D and the second sealing surface 63B in the order. Furthermore, in the first sealing step, the sealing device 160 may start moving from the middle portion of the first sealing surface 63A, the second sealing surface 63B, the third sealing surface 63C, or the fourth sealing surface 63D.

[0126] To further enhance the sealing strength of the second sealing portion 80, a resealing step is performed in step S22. The resealing method can be arbitrarily selected. For example, the resealing method can be the same as that used in the first sealing step. The resealing step can also be performed using a sealing bar to heat-seal the first to fourth sealing surfaces 63A to 63D in any order.

[0127] The sixth process of step S16 is performed before or after the fifth process. The sixth process can also be performed in parallel with the fourth process. Figure 17 As shown, in the sixth step, the manufacturing apparatus forms the first LR direction seal portion 72 extending in the LR direction. In the sixth step, the first LR direction seal portion 72 is formed so that the portion including the root portion 70X overlaps with a portion of the first FB direction seal portion 71. By completing the sixth step, the extension portion 90 is completed, which has a larger area when viewed from above than the first seal portion 70 included in the finished power storage device 10. In addition, Figure 17 The hatched portion in ⊂ represents an example of a region where the first LR direction sealing portion 72 is formed.

[0128] The seventh step, step S17, is performed after the sixth step. In this seventh step, the manufacturing apparatus injects electrolyte through opening 90X of extension 90. Following this seventh step, the edge of extension 90, including opening 90X, is heat-sealed, and an aging step is performed. Gases generated during the aging step are discharged through opening 90X.

[0129] The eighth process of step S18 is performed after the aging process is completed. Figure 18As shown, in the eighth process, the manufacturing apparatus forms the first sealing portion 70. In the eighth process, the first FB direction sealing portion 71 and the first LR direction sealing portion 72 are also sealed again. Figure 18 The hatched portion in FIG. 8 represents an example of a region where the first sealing portion 70 is formed.

[0130] The ninth step of step S19 is performed after the eighth step. In the ninth step, the manufacturing apparatus cuts off the portion of the extension portion 90 other than the first sealing portion 70 . Figure 18 The dashed-dotted line X is an example of a line indicating a position where the extension portion 90 is cut off in the ninth step.

[0131] <1-3. Transportation>

[0132] In the above embodiment, when manufacturing the electricity storage device 10 , the transport tool 200 for transporting the electrode assembly 20 , an intermediate product, or the completed electricity storage device 10 (hereinafter referred to as “transport objects”) may be used. Figure 19 It is a side view of the power storage device 10 with the transport vehicle 200 attached thereto. Figure 20 yes Figure 19 Top view of .

[0133] The transport tool 200 includes a pair of plates 211 and 212 and a connecting portion 213 connecting the plates 211 and 212. The plate 211 covers one first surface 41 of the exterior body 40. The plate 212 covers the other first surface 41 of the exterior body 40. A handle 211A is attached to the plate 211. This allows the operator to easily grip the transport tool 200. Alternatively, the handle 211A may be omitted.

[0134] The area of ​​the pair of plates 211 and 212 in a plan view is larger than the area of ​​the first surface 41 of the exterior body 40. Therefore, in the LR direction, the pair of plates 211 and 212 protrude from the first surface 41. Holes 211X and 212X for inserting the connecting portion 213 are formed in the portions of the pair of plates 211 and 212 that protrude from the first surface 41.

[0135] The specific structure of the connecting portion 213 can be arbitrarily selected as long as it can connect the pair of plates 211 and 212. To facilitate attachment and detachment of the transport tool 200 to the transported object, the connecting portion 213 is preferably detachable from the pair of plates 211 and 212. In this embodiment, the connecting portion 213 is a bolt. For example, the connecting portion 213 is inserted into the holes 211X and 212X and secured to the pair of plates 211 and 212 with a nut.

[0136] The number of connecting parts 213 included in the transport vehicle 200 can be arbitrarily selected. In this embodiment, the transport vehicle 200 includes six connecting parts 213. The transport vehicle 200 may also include 1 to 5 or 7 or more connecting parts 213.

[0137] <1-4. Functions and Effects of the Power Storage Device>

[0138] According to the power storage device 10 , since the protrusion 60B is formed on the lid 60 , the fixing tool 100 can be attached to the protrusion 60B. Since the lid 60 can be fixed relative to the electrode body 20 in the intermediate body, the position of the lid 60 relative to the electrode body 20 is highly accurate.

[0139] [2. Modifications]

[0140] The above-described embodiments are examples of possible forms of the power storage device, cover, fixing tool, method for manufacturing a power storage device, and conveying tool of the present invention, and are not intended to limit the forms. The power storage device, cover, fixing tool, method for manufacturing a power storage device, and conveying tool of the present invention can adopt forms different from those illustrated in the embodiments. One example is a form in which a portion of the structure of the embodiment is replaced, changed, or omitted, or a form in which a new structure is added to the embodiment. Several examples of modified examples of the embodiment are shown below. In addition, the following modified examples can be combined with each other as long as they are not technically inconsistent.

[0141] <2-1>

[0142] In the above-described embodiment, the structure of the cover 60 can be arbitrarily changed. Figure 21 2 is a perspective view of a modified cover 260. The cover 260 may also include a main body 60A and a thick wall portion 261 protruding from the second surface 62 of the main body 60A. The number of thick wall portions 261 included in the cover 260 can be arbitrarily selected. Figure 21 In the example shown, the cover body 260 includes four thick-walled portions 261. The cover body 260 may also include 1 to 3, or more than 5 thick-walled portions 261. A hole 260X is formed in the thick-walled portion 261 and the main body 60A. The hole 260X preferably does not penetrate the thick-walled portion 261 and the main body 60A. In this modification, the protrusion 60B is a screw that can be inserted into the hole 260X. Any fixing component can also be inserted into the hole 260X. A female thread can also be formed on the inner circumferential surface of the hole 260X. In addition, Figure 21In the illustrated variation, a thick-walled portion may be formed on the first surface 61 of the main body 60A at a position opposing the thick-walled portion 261 across the main body 60A. In this case, the hole 260X preferably does not penetrate the thick-walled portion 261, the main body 60A, and the thick-walled portion formed on the first surface 61. Furthermore, the thick-walled portion 261 and the thick-walled portion formed on the first surface 61 do not need to oppose each other across the main body 60A. In short, the thick-walled portion may be formed on at least one of the first surface 61 and the second surface 62.

[0143] Figure 22 This is a three-dimensional view of another modified example of the cover 360. The cover 360 may also include a main body 60A and a protrusion 360B protruding from the second surface 62 of the main body 60A. The protrusion 360B may also be formed integrally with the main body 60A. The protrusion 360B is, for example, a shape corresponding to a lead pin provided to suppress warping of the cover 60 when the cover 360 is insert-molded. In addition, Figure 22 In the embodiment, the number of protrusions 360B may be 1, 2 or more than 4.

[0144] Figure 23 1 is a side view of the power storage device 10 including the cover 460 of another modified example. The cover 460 has a protrusion 460B. The protrusion 460B has a fracture 460X. The fracture 460X is a portion of the protrusion 460B that is processed to be thinner. In the protrusion 460B, the position where the fracture 460X is formed can be arbitrarily selected. In the present embodiment, the fracture 460X is formed in the middle of the protrusion 460B. The fracture 460X can also be formed at the root of the protrusion 460B. In the manufacturing process of the power storage device 10, the position of the protrusion 460B relative to the electrode body 20 is fixed by the fixing tool 471. The movement of the electrode body 20 is restricted by the fixing tool 472. In the manufacturing process of the power storage device 10, for example, the ninth process (see Figure 7 ) After the fixing tool 471 is removed from the protrusion 460B, the protrusion 460B is broken at the breaking portion 460X. Since the protrusion 460B is shortened, the volume of the cover 460 and the volume of the power storage device 10 can be reduced. Therefore, the energy density of the power storage device 10 can be improved.

[0145] <2-2>

[0146] In the above-described embodiment, the structure of the cover fixing portion 110 of the fixing tool 100 can be arbitrarily changed. Figure 24 This is a perspective view of a modified cover fixing portion 510. The cover fixing portion 510 can be used to fix, for example Figure 22 The cover 360 is shown.

[0147] The cover fixing portion 510 includes a first fixing portion 511 and a second fixing portion 512 configured to clamp the protrusion 360B. The first fixing portion 511 includes three recessed portions 511A recessed toward the side opposite the second fixing portion 512. The second fixing portion 512 includes three recessed portions 512A recessed toward the side opposite the first fixing portion 511. The protrusion 360B is clamped and fixed between the opposing recessed portions 511A and 512A. Preferably, a buffer member 520 is disposed in the recessed portions 511A at both ends of the three recessed portions 511A. The buffer member 520 is preferably flexible enough to deform along the shape of the protrusion 360B. When clamping the protrusion 360B, the buffer member 520 can flexibly deform to match the shape of the protrusion 360B. Therefore, even if the shape of the protrusion 360B varies slightly from one individual to the next, the protrusion 360B can be properly fixed. Furthermore, protrusion 360B is less likely to be damaged because it is protected by buffer 520. The number of recesses 511A and 512A formed in cover fixing portion 510 can be arbitrarily changed according to the number of protrusions 360B of cover 360 to be fixed.

[0148] <2-3>

[0149] In the above embodiment, from the viewpoint of improving the adhesion between the outer film 50 and the electrode body 20, as shown in FIG. Figure 25 As shown, a strip-shaped component 700 can be wound around the electrode body 20 and bonded to the inner surface of the outer film 50. Any material can be used to constitute the strip-shaped component 700. For example, a sheet made of olefin resin can be used as the strip-shaped component 700. The strip-shaped component 700 can be bonded to the inner surface of the outer film 50 by an adhesive or the like, or can be bonded to the inner surface of the outer film 50 by heat sealing. The strip-shaped component 700 may be bonded to the electrode body 20 or not. From the viewpoint of further improving the adhesion between the outer film 50 and the electrode body 20, the strip-shaped component 700 is preferably bonded to the electrode body 20. In the electrode body 20, the position where the strip-shaped component 700 is wound can be arbitrarily selected. Figure 25 In the example shown, the belt-shaped member 700 is wound around the substantially center in the FB direction of the electrode assembly 20. In this modification, the protruding portion 60B of the lid 60 can also be omitted.

[0150] <2-4>

[0151] In the above embodiment, the third step (winding step) of the method for manufacturing the power storage device 10 can be arbitrarily changed. For example, in the above embodiment, the size of the outer film 50 used in the third step is a size that does not protrude from the sealing surface 63 of the cover 60 in the FB direction. However, if Figure 26As shown, the exterior film 50 may have a remaining portion 50X extending from the sealing surface 63 of the lid 60. The remaining portion 50X is preferably cut in any step performed after the winding step or folded in any direction.

[0152] <2-5>

[0153] In the above embodiment, the fifth step (sealing step) of the method for manufacturing the power storage device 10 can be arbitrarily selected. For example, in the fifth step, from the perspective of improving the sealing performance of the boundaries 64 to 67 of the cover body 60, it is preferable to sequentially join the adjacent sealing surfaces of the cover body 60. For example, Figure 27 As shown, when a sealing strip 610 of a heat sealing device is used, for example, the first sealing surface 63A, the third sealing surface 63C, the fourth sealing surface 63D, and the second sealing surface 63B are preferably bonded to the exterior film 50 in this order. In another example, the second sealing surface 63B, the fourth sealing surface 63D, the third sealing surface 63C, and the first sealing surface 63A may be bonded to the exterior film 50 in this order. The first sealing surface 63A and the fourth sealing surface 63D may also be heat-sealed before the second sealing surface 63B and the third sealing surface 63C of the lid body 60.

[0154] In the fifth step (sealing step), the second sealed portion 80 can also be formed using a heat sealing device. In this variation, it is preferable to control the amount by which the sealing strip 610 of the heat sealing device is pressed into the exterior film 50 and the lid 60. When controlling the pressure of the sealing strip 610, the heat-fusible resin layer 53 of the exterior film 50 may excessively melt, causing polymer accumulation between the sealing surface 63 of the lid 60 and the exterior film 50. Polymer accumulation can be a major cause of cracks in the exterior body 40. Therefore, it is preferable to control the amount by which the heat-fusible resin layer 53 is pressed to a level that prevents excessive melting of the heat-fusible resin layer 53. Furthermore, the amount by which the sealing strip 610 is pressed is determined by the distance the sealing strip 610 approaches the lid 60 from the reference position, where the sealing strip 610 contacts the surface of the exterior film 50. For example, the amount of pressure is preferably approximately half the thickness of the heat-fusible resin layer 53.

[0155] The pressing amount of the sealing strip 610 can be determined by, for example, Figure 28 The sealing strip 610 shown is connected to an electric cylinder 800, which is controlled by the electric cylinder 800. The electric cylinder 800 can use a known structure. The electric cylinder 800 includes a main body 810 including a motor, etc., and a rod 820 that varies the amount of protrusion relative to the main body 810. The sealing strip 610 is fixed to the front end of the rod 820.

[0156] Figure 28 1 is a diagram showing the initial position of the weather strip 610 . Figure 29 : is a diagram showing the reference position of the sealing strip 610. Figure 28 As shown, in the initial position of the sealing strip 610, the sealing strip 610 is separated from the outer film 50 and the cover 60. In the initial position, the sealing strip 610 is close to the outer film 50 and the cover 60 by increasing the protrusion of the rod 820 relative to the main body 810. Figure 29 The reference position shown. Alternatively, the amount of pressurization of the sealing strip 610 may be controlled by an air cylinder connected to the sealing strip 610, instead of the electric cylinder 800. When an air cylinder is used instead of the electric cylinder 800, a limiting member that acts as a buffer against the sealing strip 610 is preferably disposed around the intermediate body at the position of the predetermined pressurization amount to prevent the sealing strip 610 from being pressed in beyond the predetermined pressurization amount.

[0157] In addition, from the viewpoint of suppressing the formation of polymer accumulation, it is preferable to form the second sealing portion 80 in as short a time as possible. Therefore, in the above embodiment, the cover body 60 is preferably preheated in any process implemented before the fifth process. By preheating the cover body 60, for example, even when the melting point of the material constituting the cover body 60 is higher than the melting point of the material constituting the heat-fusible resin layer 53 of the exterior film 50, the second sealing portion 80 can be formed in a short time. In addition, depending on the method for forming the second sealing portion 80, the first sealing surface 63A, the second sealing surface 63B, the third sealing surface 63C and the fourth sealing surface 63D can be heated simultaneously or in any order. The cover body 60 can be heated by any means such as a heating bar, ultrasonic waves or an infrared lamp.

[0158] The surface of the sealing surface 63 of the cover 60 may have minute irregularities, for example. Therefore, when the second sealing portion 80 is formed by a heat sealing device, the sealing strength may vary between each portion of the second sealing portion 80. Furthermore, the size of the polymer accumulation portion formed between the outer film 50 and the cover 60 may also vary. From the perspective of reducing such variations in sealing strength and the size of the polymer accumulation portion, when a heat sealing device is used in the fifth step, as shown in FIG. Figure 30 As shown, the second sealing portion 80 is preferably formed with a heat-resistant elastomer 910 sandwiched between the sealing strip 610 and the exterior film 50. The material constituting the elastomer 910 is an elastomer having a melting point above the temperature required for heat sealing. Examples of the material constituting the elastomer 910 include a rubber sheet, a silicon sheet, a polyurethane sheet, or a fluororesin sheet.

[0159] Similarly, from the perspective of reducing the variation in the sealing strength of the second sealing portion 80, when a heat sealing device is used in the fifth step, it is preferable to form the second sealing portion 80 with at least the cover 60 disposed on the elastic body 920. The electrode body 20 may also be disposed on the elastic body 920. In addition to the materials exemplified as the materials constituting the elastic body 910, sponge may also be used as the material constituting the elastic body 920. Figure 30 In the example shown, the elastic body 910 or the elastic body 920 can be omitted.

[0160] <2-6>

[0161] In the above-described embodiment, the first step and the second step of the method for manufacturing the power storage device 10 can be arbitrarily changed. Figure 31 1 is a flowchart showing a modified example of the method for manufacturing the power storage device 10. The modified example of the method for manufacturing the power storage device 10 includes a thirty-first step and a thirty-second step.

[0162] In the thirty-first step (connection step) of step S31 , the manufacturing apparatus connects the electrode body 20 and the electrode terminal 30 .

[0163] The 32nd step (arrangement step) of step S32 is performed after the 31st step. In the 32nd step, the manufacturing apparatus arranges the lid members 60 at both ends of the electrode assembly 20 . Figure 32 This figure relates to step 32. Hereinafter, the electrode terminal 30 and the cover 60 disposed on one side of the electrode body 20 are referred to as the electrode terminal 30L and the cover 60L, respectively. The electrode terminal 30 and the cover 60 disposed on the other side of the electrode body 20 are referred to as the electrode terminal 30R and the cover 60R, respectively.

[0164] The manufacturing apparatus uses an image processing device (not shown) to position the cover 60L relative to the electrode terminal 30L. Figure 31 As shown, during the placement process, for example, one cover 60L is positioned relative to one electrode terminal 30L using the long side PAX and short side PBX of one electrode terminal 30L in a plan view as reference. An image processing device detects the short side PBX through transillumination and calculates a correction amount relative to the opposite reference side based on this positional information. Next, the manufacturing apparatus positions the other cover 60R relative to the other electrode terminal 30R using the long side PAX and short side PBX of one electrode terminal 30L as reference.

[0165] When positioning the other cover 60R, the other cover 60R may be positioned relative to the other electrode terminal 30R using the long side PAY and short side PBY of the other electrode terminal 30R as a reference when viewed from above. Furthermore, in the third step (winding step), the exterior film 50 may be positioned relative to the intermediate body based on the long side PAX and short side PBX, or the long side PAY and short side PBY, set in the placement step.

[0166] <2-7>

[0167] In the above embodiment, the cover 60 may have a recessed portion recessed from the second surface 62 toward the first surface 61 in addition to or instead of the protrusion 60B. The cover 60 is fixed by inserting the protrusion of the fixing tool 100 into the recessed portion.

[0168] <2-8>

[0169] In the above embodiment, the cover 60 may be formed with at least one of a protrusion protruding from the first surface 61 and a recessed portion recessed from the first surface 61 toward the second surface 62. The electrode body 20 is fixed by at least one of the protrusion and the recessed portion formed on the first surface 61. In addition, the shape of the electrode body 20 is maintained by at least one of the protrusion and the recessed portion formed on the first surface 61.

[0170] <2-9>

[0171] In the above embodiment, the exterior film 50 of the power storage device 10 may extend further outward in the FB direction than the cover 60. The portion of the exterior film 50 extending beyond the cover 60 may be folded like a gable top bag or a brick pack bag.

[0172] Description of Reference Numerals

[0173] 10: Power storage device

[0174] 20: Electrode body

[0175] 30: Electrode terminal

[0176] 40: Exterior body

[0177] 40A: Opening

[0178] 50: Exterior film

[0179] 60, 260, 360, 460: cover

[0180] 60B, 360B, 460B: protrusion

[0181] 260X: Through hole

[0182] 261: Thick wall part

[0183] 460X: fracture

[0184] 61: Side 1

[0185] 62: Side 2

[0186] 100: Fixing tools

[0187] 110, 510: Cover fixing part

[0188] 200: Transportation

[0189] 211: Board

[0190] 211A: Handle

[0191] 212: Board

[0192] 213: Connection

[0193] 700: Strip components

[0194] 910: Elastomer

[0195] 920: Elastomer.

Claims

1. A power storage device, characterized in that: include: Electrode body; and An outer body for sealing the electrode body, The outer body comprises: an outer film covering the electrode body so as to form an opening; and a cover body disposed at the opening, The cover body has: a first surface facing the electrode body; a second side opposite to the first side; and At least one of a protrusion protruding from the second surface and a recessed portion recessed from the second surface toward the first surface.

2. The power storage device according to claim 1, wherein: The cover comprises a main body having the first surface and the second surface, The protrusion includes a securing member engaged with the body.

3. The power storage device according to claim 1, wherein: The cover comprises a main body having the first surface and the second surface, The main body has a thick wall portion protruding from the second surface, Holes are formed in the thick wall portion and the main body.

4. The power storage device according to claim 1, wherein: The protrusion has a break portion.

5. A fixing tool, characterized in that: It can be used in the manufacture or use of the power storage device according to any one of claims 1 to 4, The fixing tool includes a cover fixing portion fixed to at least one of the protruding portion and the recessed portion.

6. A cover, characterized in that: The invention can be used in the power storage device according to any one of claims 1 to 4. The cover body has: First side; a second side opposite to the first side; and At least one of a protrusion protruding from the second surface and a recessed portion recessed from the second surface toward the first surface.

7. A method for manufacturing an electricity storage device, characterized in that: The power storage device includes an electrode body and an outer body for sealing the electrode body. The outer body comprises: an outer film covering the electrode body so as to form an opening; and A cover for closing the opening, The cover body has: a first surface facing the electrode body; a second side opposite to the first side; and at least one of a protrusion protruding from the second surface and a recessed portion recessed from the second surface toward the first surface, The method for manufacturing an electricity storage device includes the step of fixing a position of the cover relative to the electrode body by fixing a tool to at least one of the protrusion and the recess of the cover disposed on a side of the electrode body.

8. A transport tool for an electrode body, characterized in that: include: at least one pair of plates sandwiching the electrode body; and A connecting portion connects the pair of plates.

9. The transport tool according to claim 8, characterized in that: Also included is a handle mounted to at least one of the pair of plates.

Images