Power storage device, fixing jig, and manufacturing method for power storage device

Abstract

To provide a power storage device that can seal an electrode body suitably with an exterior body, a fixing jig used for this power storage device or an intermediate body, and a manufacturing method for this power storage device.SOLUTION: A power storage device includes an electrode body and an exterior body that seals the electrode body. The exterior body includes an exterior film covering the electrode body, a main body part that covers at least the electrode body with the exterior film, an extension part in which the exterior film is extended outward relative to the main body part, a first sealing part in which surfaces of the extension part where the exterior films face each other are sealed, and a fixing jig that suppresses the movement of the extension part relative to the main body part.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to an electricity storage device, a fixing jig, and a method for manufacturing an electricity storage device. [Background technology]

[0002] Patent Document 1 discloses an all-solid-state battery as an example of an electricity storage device. This all-solid-state battery includes an electrode body and an exterior body that seals the electrode body. The exterior body includes an exterior film that is wrapped around the electrode body to have an opening, and a lid body that is placed on the opening. The exterior film includes a main body that encases the electrode body and the lid body, and a protruding portion that protrudes outward from the main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-153504 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned electricity storage device, since the protruding portion is movable relative to the main body, the protruding portion, particularly the base portion, is prone to material fatigue, which may cause the portion of the exterior film constituting the protruding portion to break, thereby reducing the sealing performance of the electricity storage device.

[0005] An object of the present invention is to provide an electricity storage device in which an electrode assembly can be suitably sealed with an exterior body, a fixing jig used for this electricity storage device or an intermediate product, and a manufacturing method for this electricity storage device. [Means for solving the problem]

[0006] The energy storage device according to a first aspect of the present invention comprises an electrode body and an exterior body that seals the electrode body, and the exterior body includes an exterior film that wraps the electrode body, a main body in which at least the electrode body is wrapped by the exterior film, a protrusion portion in which the exterior film protrudes outward beyond the main body, a first sealing portion in which facing surfaces of the exterior film in the protrusion portion are sealed, and a fixing jig that prevents the protrusion portion from moving relative to the main body.

[0007] An electricity accumulation device according to a second aspect of the present invention is the electricity accumulation device according to the first aspect, wherein the fixing jig has a first fixing portion disposed so as to straddle the main body portion and the protruding portion.

[0008] An electricity accumulation device according to a third aspect of the present invention is the electricity accumulation device according to the first or second aspect, wherein the fixing jig has a second fixing portion that supports the overhanging portion.

[0009] An energy storage device according to a fourth aspect of the present invention is the energy storage device according to the first aspect, wherein the fixing jig has a first fixing portion arranged to straddle the main body portion and the protrusion portion, a second fixing portion supporting the protrusion portion, and a connecting portion connecting the first fixing portion and the second fixing portion.

[0010] An electricity storage device according to a fifth aspect of the present invention is the electricity storage device according to any one of the first to fourth aspects, wherein the exterior body further includes a lid body that seals the electrode body together with the exterior film.

[0011] An electricity accumulation device according to a sixth aspect of the present invention is the electricity accumulation device according to the fifth aspect, wherein the lid has a convex portion or a concave portion, and the fixing jig is connected to the convex portion or the concave portion.

[0012] An energy storage device according to a seventh aspect of the present invention is an energy storage device according to any one of the first to sixth aspects, wherein the protrusion portion is folded starting from a position away from a base of the first sealing portion, a gap is formed between the protrusion portion and the main body portion, and the fixing jig is positioned in at least a part of the gap.

[0013] A fixing jig according to an eighth aspect of the present invention is a fixing jig attached to at least one of an electric storage device and an intermediate body of the electric storage device. The electric storage device or the intermediate body includes an electrode body, an exterior film that encases the electrode body, a main body in which at least the electrode body is encased by the exterior film, and a protruding portion in which the exterior film protrudes outward beyond the main body, and the fixing jig is configured to suppress movement of the protruding portion relative to the main body.

[0014] A manufacturing method for an electricity storage device according to a ninth aspect of the present invention is a manufacturing method for an electricity storage device including an electrode body and an exterior body that seals the electrode body. The exterior body includes an exterior film that wraps the electrode body, a main body in which at least the electrode body is wrapped by the exterior film, a protruding portion in which the exterior film protrudes outward beyond the main body, and a first sealing portion in which opposing surfaces of the exterior film in the protruding portion are sealed. The manufacturing method for the electricity storage device includes a packaging step of wrapping the electrode body with the exterior film so as to form the main body and the protruding portion, and a jig arrangement step that is performed after the packaging step and that arranges a fixing jig that suppresses movement of the protruding portion relative to the main body. Effect of the Invention

[0015] The electricity storage device, the fixing jig, and the method for manufacturing the electricity storage device according to the present invention can contribute to suitably sealing the electrode assembly with the exterior body. [Brief description of the drawings]

[0016] [Figure 1A]FIG. 4 is a perspective view of the electricity storage device according to the embodiment with a fixing jig removed. [Figure 1B] 1B is a diagram showing a method for measuring the seal strength of a second sealing portion of the electricity storage device in FIG. 1A. [Diagram 2] 1B is a cross-sectional view showing a layer structure of an exterior film included in the electricity storage device of FIG. 1A. [Diagram 3] 1B is a side view of a lid provided in the electricity storage device of FIG. 1A. [Figure 4] FIG. 1B is a diagram showing the state in which the exterior film of the power storage device of FIG. 1A is unfolded. [Diagram 5] 1B is a front view of the power storage device in FIG. 1A with the protruding portion folded. FIG. [Figure 6] FIG. 2 is a perspective view of the electricity storage device in FIG. 1A with a fixing jig attached thereto. [Figure 7] FIG. 7 is a perspective view of the fixture of FIG. 6; [Figure 8] 6 is a front view of the electricity accumulation device in FIG. 5 before the protruding portion is folded up. [Figure 9] 9 is a front view of the electricity storage device in FIG. 8 with a fixing jig attached and the protruding portion folded. [Figure 10] FIG. 10 is a perspective view of the fixture of FIG. 9 . [Figure 11] 4 is a flowchart showing an example of a method for manufacturing the electricity storage device in FIG. 1A. [Figure 12] 1B is a diagram showing a third step of the method for producing the electricity storage device in FIG. 1A. [Figure 13] FIG. 2 is a diagram showing a fourth step of the method for producing the electricity storage device in FIG. 1A. [Figure 14] 1B is a diagram showing the fourth and fifth steps of the method for producing the electricity storage device in FIG. 1A. [Figure 15] 1B is a diagram showing another example of the fourth step and the fifth step of the method for producing the electricity storage device in FIG. 1A. [Figure 16] FIG. 1B is a diagram showing a fifth step of the method for producing the electricity storage device in FIG. 1A. [Figure 17] FIG. 1B is a diagram showing a sixth step of the method for producing the electricity storage device in FIG. 1A. [Figure 18] FIG. 1B is a diagram showing a seventh step of the method for producing the electricity storage device in FIG. 1A. [Figure 19] FIG. 1B is a diagram showing an eighth step of the method for producing the electricity storage device in FIG. 1A. [Figure 20] FIG. [Figure 21] FIG. 13 is a perspective view of a fixing jig according to another modified example. [Figure 22] FIG. 13 is a perspective view of an electricity accumulation device in a state in which a fixing jig according to still another modified example is attached. [Figure 23] FIG. 13 is a perspective view of an electricity accumulation device in a state in which a fixing jig according to still another modified example is attached. [Figure 24] FIG. 13 is a perspective view of an electricity accumulation device according to a modified example. [Diagram 25] FIG. 13 is a perspective view of an electricity storage device according to another modified example. [Figure 26] FIG. 13 is a perspective view of an electricity storage device according to still another modified example. [Figure 27] FIG. 13 is a perspective view of an electricity storage device according to still another modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an electricity storage device according to one embodiment of the present invention will be described with reference to the drawings. In this specification, a numerical range indicated by "to" means "not less than" or "not more than." For example, the expression "2 to 15 mm" means 2 mm or more and 15 mm or less.

[0018] [1. Embodiment] <1-1. Configuration of the power storage device> FIG. 1A is a perspective view that shows a schematic diagram of a state in which a fixing jig 100 is removed from an electric storage device 10 of an embodiment. FIG. 1B is a diagram that shows a method for measuring the seal strength of a second sealing portion 80 of the electric storage device 10 of FIG. 1A. FIG. 2 is a cross-sectional view that shows a layer structure of an exterior film 50 included in the electric storage device 10 of FIG. 1A. FIG. 3 is a side view of a lid body 60 included in the electric storage device 10 of FIG. 1A. FIG. 4 is a diagram of an exterior film 50 included in the electric storage device 10 of FIG. 1A in an unfolded state. FIG. 5 is a front view of the electric storage device 10 of FIG. 1A in a state in which a portion including a protruding portion 50Y is folded. FIG. 6 is a perspective view of the electric storage device 10 of FIG. 1A in which a fixing jig 100 is attached. In FIG. 1A, the direction of the arrow UD indicates the thickness direction of the electric storage device 10, the direction of the arrow LR indicates the width direction of the electric storage device 10, and the direction of the arrow FB indicates the depth direction of the electric storage device 10. The directions indicated by the arrows UDLRFB are the same in the subsequent figures.

[0019] The power storage device 10 includes an electrode body 20, an electrode terminal 30, and an exterior body 40. The electrode body 20 includes electrodes (positive and negative electrodes) constituting a power storage member such as a lithium ion battery, a capacitor, an all-solid-state battery, a semi-solid battery, a quasi-solid battery, a polymer battery, an all-resin battery, a lead-acid battery, a nickel-metal hydride battery, a nickel-cadmium battery, a nickel-iron battery, a nickel-zinc battery, a silver oxide-zinc battery, a metal-air battery, a polyvalent cation battery, or a capacitor, and a separator. In this embodiment, the shape of the electrode body 20 is an approximately rectangular parallelepiped. Note that the term "approximately rectangular parallelepiped" includes, in addition to a complete rectangular parallelepiped, a solid body that can be regarded as a rectangular parallelepiped by modifying the shape of a part of the outer surface, for example. The shape of the electrode body 20 may be, for example, a cylinder or a polygonal prism.

[0020] In this embodiment, the power storage device 10 includes two electrode terminals 30. The electrode terminals 30 are metal terminals used for inputting and outputting electric power in the electrode body 20. One end of the electrode terminal 30 is electrically connected to an electrode (positive electrode or negative electrode) included in the electrode body 20. The other end of the electrode terminal 30 protrudes outward from an edge of the exterior body 40, for example. Note that the electrode terminal 30 may not protrude from the exterior body 40, for example, as long as it is capable of inputting and outputting electric power to and from the electrode body 20. When the cover body 60 described later is made of, for example, a metal, the cover body 60 may also function as the electrode terminal 30. In this case, the cover body 60 having the function as an electrode terminal may or may not protrude from the exterior body 40.

[0021] The metal material constituting the electrode terminal 30 is, for example, aluminum, nickel, copper, etc. For example, when the electrode body 20 is a lithium ion battery, the electrode terminal 30 connected to the positive electrode is usually made of aluminum, etc., and the electrode terminal 30 connected to the negative electrode is usually made of copper, nickel, etc. The outermost layer of the electrode body 20 does not necessarily have to be an electrode, and may be, for example, a protective tape or a separator.

[0022] The exterior body 40 seals the electrode body 20. The exterior body 40 includes an exterior film 50 and a pair of lid bodies 60. The exterior film 50 wraps the electrode body 20 so that a pair of openings 40A are formed. In this embodiment, the exterior film 50 is wrapped around the electrode body 20 so that a pair of openings 40A are formed. The exterior body 40 has a main body portion 50X and a protruding portion 50Y. The main body portion 50X is a portion in which at least the electrode body 20 is wrapped by the exterior film 50. In this embodiment, the main body portion 50X is a portion in which the electrode body 20 and the lid body 60 are wrapped by the exterior film 50. The protruding portion 50Y is a portion in which the exterior film 50 protrudes from the main body portion 50X. The main body portion 50X has a pair of first surfaces 41A, 41B and a pair of second surfaces 42A, 42B. The pair of first surfaces 41A, 41B are substantially the same size. The pair of second surfaces 42A, 42B are substantially the same size. The pair of first surfaces 41A, 41B have areas larger than the pair of second surfaces 42A, 42B. The pair of lid bodies 60 are respectively disposed on the sides of the electrode body 20 so as to close the pair of openings 40A.

[0023] For example, there is a method of forming a storage portion (recess) for storing the electrode body 20 in the exterior film 50 through cold forming. However, it is not necessarily easy to form a deep storage portion by such a method. If an attempt is made to form a deep storage portion (recess) (for example, a forming depth of 15 mm) by cold forming, pinholes or cracks will occur in the exterior film 50, which is likely to lead to a decrease in battery performance. On the other hand, in this embodiment, the exterior body 40 seals the electrode body 20 by wrapping the exterior film 50 around the electrode body 20, so that the electrode body 20 can be easily sealed regardless of the thickness of the electrode body 20. Note that in order to reduce the dead space between the electrode body 20 and the exterior film 50 so as to improve the volumetric energy density of the electricity storage device 10 and to improve the cooling efficiency, it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20. Moreover, in an all-solid-state battery, it is necessary to apply a high pressure uniformly from the outer surface of the battery to exert battery performance, and therefore it is necessary to eliminate the space between the electrode body 20 and the exterior film 50. Therefore, it is preferable that the exterior film 50 is wrapped around the electrode body 20 so as to be in contact with the outer surface of the electrode body 20.

[0024] The exterior film 50 is, for example, a laminate (laminate film) having, in this order, a base layer 51, a barrier layer 52, and a heat-sealable resin layer 53. Note that the exterior film 50 does not need to include all of these layers, and for example, does not need to include the barrier layer 52. In other words, the exterior film 50 only needs to be made of a material that is flexible and easily bendable, and may be made of, for example, a resin film.

[0025] The base layer 51 included in the exterior film 50 is a layer for imparting heat resistance to the exterior film 50 and suppressing the occurrence of pinholes that may occur during processing or distribution. The base layer 51 is configured to include at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer. For example, the base layer 51 includes at least one layer of a stretched polyester resin layer and a stretched polyamide resin layer, so that the barrier layer 52 can be protected during processing of the exterior film 50 and breakage of the exterior film 50 can be suppressed. In addition, from the viewpoint of increasing the tensile elongation of the exterior film 50, the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer. Furthermore, in terms of excellent puncture strength or impact strength, the stretched polyester resin layer is more preferably a biaxially stretched polyethylene terephthalate (PET) film, and the stretched polyamide resin layer is more preferably a biaxially stretched nylon (ONy) film. The base layer 51 may be configured to include both a stretched polyester resin layer and a stretched polyamide resin layer. The thickness of the base layer 51 is, for example, preferably 5 to 300 μm, and more preferably 5 to 150 μm, from the viewpoint of film strength.

[0026] The barrier layer 52 is a layer that at least prevents the intrusion of moisture. The barrier layer 52 is bonded to the base layer 51 via, for example, an adhesive layer 54. Examples of the barrier layer 52 include metal foil, vapor deposition film, and resin layer having barrier properties. Examples of the vapor deposition film include metal vapor deposition film, inorganic oxide vapor deposition film, and carbon-containing inorganic oxide vapor deposition film, and examples of the resin layer include fluorine-containing resins such as polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having fluoroalkyl groups, and polymers mainly composed of fluoroalkyl units, and ethylene-vinyl alcohol copolymers. Examples of the barrier layer 52 include resin films having at least one of these vapor deposition films and resin layers. The barrier layer 52 may be provided in a plurality of layers. It is preferable that the barrier layer 52 includes a layer made of a metal material. Specific examples of the metal material constituting the barrier layer 52 include aluminum alloys, stainless steel, titanium steel, and steel plates. When used as a metal foil, it is preferable that the material contains at least one of an aluminum alloy foil and a stainless steel foil.

[0027] In the barrier layer 52, the layer made of the above-mentioned metal material may contain recycled metal material. Examples of recycled metal material include recycled aluminum alloy, stainless steel, titanium steel, or steel plate. These recycled materials can be obtained by known methods. The recycled aluminum alloy material can be obtained by the manufacturing method described in International Publication No. 2022 / 092231. The barrier layer 52 may be made of only recycled materials, or may be made of a mixed material of recycled materials and virgin materials. Note that recycled metal materials refer to metal materials that have been made reusable by collecting, isolating, and refining various products used in the city and waste from the manufacturing process. In addition, virgin metal materials refer to new metal materials refined from natural metal resources (raw materials) and are not recycled materials.

[0028] From the viewpoint of improving the formability or conformability of the exterior film 50, the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, and from the viewpoint of further improving the formability or conformability, the aluminum alloy foil is preferably an iron-containing aluminum alloy foil. In the iron-containing aluminum alloy foil (100% 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 making the iron content 0.1% by mass or more, an exterior film 50 having better formability can be obtained. By making the iron content 9.0% by mass or less, an exterior film 50 having better flexibility can be obtained. Examples of the soft aluminum alloy foil include aluminum alloy foils having a 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 be added as necessary. Softening can be performed by annealing treatment, etc. From the viewpoint of improving the mechanical strength of the exterior film 50, it is more preferable that the aluminum alloy foil is a hard aluminum alloy foil composed of, for example, a work-hardened aluminum alloy. Examples of the hard aluminum alloy foil include aluminum alloy foils 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.

[0029] Examples of the stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardened stainless steel foils. From the viewpoint of providing an exterior film 50 with excellent formability, the stainless steel foil is preferably made of austenitic stainless steel.

[0030] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, and SUS316L, and among these, SUS304 is particularly preferred.

[0031] In the case of a metal foil, the thickness of the barrier layer 52 should be such that it at least functions as a barrier layer to prevent the intrusion of moisture, and may be, for example, about 5 to 200 μm. The thickness of the barrier layer 52 is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and particularly preferably about 35 μm or less. The thickness of the barrier layer 52 is preferably about 9.0 μm or more, more preferably about 20 μm or more, and more preferably about 25 μm or more. Preferable ranges for the thickness of the barrier layer 52 include about 9.0 to 85 μm, about 9.0 to 50 μm, about 9.0 to 40 μm, about 9.0 to 35 μm, about 20 to 85 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 35 μm, about 25 to 85 μm, about 25 to 50 μm, about 25 to 40 μm, and about 25 to 35 μm. When the barrier layer 52 is made of an aluminum alloy foil, the above-mentioned ranges are particularly preferable. From the viewpoint of imparting high formability and high rigidity to the exterior film 50, the thickness of the barrier layer 52 is preferably about 35 μm or more, more preferably about 45 μm or more, even more preferably about 50 μm or more, and even more preferably about 55 μm or more, and is preferably about 200 μm or less, more preferably about 85 μm or less, even more preferably about 75 μm or less, and even more preferably about 70 μm or less. Preferable ranges are about 35 to 200 μm, about 35 to 85 μm, about 35 to 75 μm, about 35 to 70 μm, about 45 to 200 μm, about 45 to 85 μm, about 45 to 75 μm, about 45 to 70 μm, about 50 to 200 μm, about 50 to 85 μm, about 50 to 75 μm, about 50 to 70 μm, about 55 to 200 μm, about 55 to 85 μm, about 55 to 75 μm, and about 55 to 70 μm. When the exterior film 50 has high formability, deep drawing becomes easy, which can contribute to increasing the capacity of the electricity storage device. Furthermore, when the capacity of the electricity storage device is increased, the weight of the electricity storage device increases, but the rigidity of the exterior film 50 is increased, which can contribute to high sealing performance of the electricity storage device.In particular, when the barrier layer 52 is made of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Preferred ranges for the thickness of the stainless steel foil include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0032] In addition, when the barrier layer 52 is an aluminum foil, it is preferable that at least the surface opposite to the base layer 51 is provided with a corrosion-resistant film in order to prevent dissolution and corrosion. The barrier layer 52 may be provided with a corrosion-resistant film on both sides. Here, the corrosion-resistant film refers to a thin film that is provided with corrosion resistance (e.g., acid resistance, alkali resistance, etc.) on the barrier layer 52 by performing, for example, hydrothermal conversion treatment such as boehmite treatment, chemical conversion treatment, anodizing treatment, plating treatment such as nickel or chromium, or corrosion prevention treatment by applying a coating agent on the surface of the barrier layer 52. Specifically, the corrosion-resistant film refers to a film that improves the acid resistance of the barrier layer 52 (acid-resistant film), a film that improves the alkali resistance of the barrier layer 52 (alkali-resistant film), etc. The treatment for forming the corrosion-resistant film may be one type, or two or more types may be combined. In addition, not only one layer but also multiple layers may be formed. Furthermore, among these treatments, hydrothermal conversion treatment and anodizing treatment are treatments in which the metal foil surface is dissolved by a treatment agent to form a metal compound with excellent corrosion resistance. Note that these treatments may also be included in the definition of chemical conversion treatment. In addition, when the barrier layer 52 has a corrosion-resistant coating, the corrosion-resistant coating is also included in the barrier layer 52.

[0033] The corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 during molding of the exterior film 50, prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride produced by a reaction between an electrolyte and moisture, and in particular prevents dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52 when the barrier layer 52 is an aluminum alloy foil, and also improves the adhesion (wettability) of the surface of the barrier layer 52, thereby preventing delamination between the base layer 51 and the barrier layer 52 during heat sealing and between the base layer 51 and the barrier layer 52 during molding.

[0034] The heat-sealable resin layer 53 is bonded to the barrier layer 52, for example, via an adhesive layer 55. The heat-sealable resin layer 53 included in the exterior film 50 is a layer that imparts heat-sealing sealability to the exterior film 50. Examples of the heat-sealable resin layer 53 include resin films made of polyester resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin resins such as polyethylene resins and polypropylene resins, or acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. The thickness of the heat-sealable resin layer 53 is preferably, for example, 20 to 300 μm, and more preferably 40 to 150 μm, in terms of sealability and strength.

[0035] The exterior film 50 preferably has one or more layers having a buffer function (hereinafter referred to as "buffer layer") outside the heat-sealable resin layer 53, more preferably outside the barrier layer 52. The buffer layer may be laminated on the outside of the base material layer 51, or the base material layer 51 may also function as a buffer layer. When the exterior film 50 has multiple buffer layers, the multiple buffer layers may be adjacent to each other, or may be laminated via the base material layer 51, the barrier layer 52, etc.

[0036] The material constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. The material having cushioning properties is, for example, rubber, nonwoven fabric, or foam sheet. The rubber is, for example, natural rubber, fluororubber, or silicone rubber. The rubber hardness is preferably about 20 to 90. The material constituting the nonwoven fabric is preferably a material having excellent heat resistance. When the buffer layer is made of nonwoven fabric, the lower limit of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and more preferably 1000 μm. When the buffer layer is made of nonwoven fabric, the upper limit of the thickness of the buffer layer is preferably 5000 μm, and more preferably 3000 μm. The thickness of the buffer layer is preferably in the range of 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm. Among these, the thickness of the buffer layer is most preferably in the range of 1000 μm to 3000 μm.

[0037] When the buffer layer is made of rubber, the lower limit of the thickness of the buffer layer is preferably 0.5 mm. When the buffer layer is made of rubber, the upper limit of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, and more preferably 2 mm. When the buffer layer is made of rubber, the preferred range of the thickness of the buffer layer is 0.5 mm to 10 mm, 0.5 mm to 5 mm, or 0.5 mm to 2 mm.

[0038] When the exterior film 50 has a buffer layer, the buffer layer functions as a cushion, thereby preventing the exterior film 50 from being damaged by impact when the electricity storage device 10 is dropped or by handling during production of the electricity storage device 10.

[0039] The lid body 60 is, for example, plate-shaped and made of, for example, a resin material. The lid body 60 may be formed by, for example, cold forming the exterior film 50, or may be a metal molded product. The material constituting the lid body 60 may include at least two or more materials of a metal oxide, a carbon material, and a rubber material, and may include a metal oxide, a carbon material, and a rubber material. The lid body 60 has a lid main body 60A. The lid main body 60A has a first surface 61, a second surface 62, and a lid seal portion 63. The first surface 61 faces the electrode body 20. The second surface 62 is a surface opposite to the first surface 61. The lid seal portion 63 is connected to the first surface 61 and the second surface 62, and is heat-sealed to the heat-fusible resin layer 53 of the exterior film 50. The lid seal portion 63 includes a first seal surface 63A, a second seal surface 63B, a third seal surface 63C, and a fourth seal surface 63D. The first seal surface 63A constitutes the upper surface of the lid body 60. The first seal surface 63A extends in a first direction (LR direction in this embodiment) in a front view of the lid body 60. The second seal surface 63B and the third seal surface 63C are connected to the first seal surface 63A and constitute the side surface of the lid body 60. The second seal surface 63B and the third seal surface 63C extend in a second direction (UD direction in this embodiment) intersecting the first direction in a front view of the lid body 60. In this embodiment, the first direction and the second direction are orthogonal to each other in a front view of the lid body 60. The first direction and the second direction do not have to be orthogonal to each other in a front view of the lid body 60. The fourth seal surface 63D constitutes the lower surface of the lid body 60. The fourth sealing surface 63D extends in a first direction (the LR direction in this embodiment) when the lid 60 is viewed from the front.

[0040] When the lid body 60 is plate-shaped, it is preferable that the lid body 60 has a certain degree of thickness so that deformation of the exterior body 40 is suppressed even when the power storage device 10 is arranged in a stacked manner. From another viewpoint, when the lid body 60 is plate-shaped, it is preferable that the lid seal portion 63 of the lid body 60 has a certain degree of width so that the lid seal portion 63 of the lid body 60 and the exterior film 50 can be suitably heat-sealed when the second sealing portion 80 is formed. The minimum value of the thickness of the lid body 60 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum value of the thickness of the lid body 60 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum value of the thickness of the lid body 60 may be 20 mm or more. The preferred ranges of the thickness of the material constituting the lid body 60 are 1.0 mm to 20 mm, 1.0 mm to 15 mm, 1.0 mm to 10 mm, 3.0 mm to 20 mm, 3.0 mm to 15 mm, 3.0 mm to 10 mm, 4.0 mm to 20 mm, 4.0 mm to 15 mm, and 4.0 mm to 10 mm. In this embodiment, when the lid body 60 is expressed as a plate-like body, the embodiment in which the lid body 60 is composed only of a film defined by the [packaging terminology] standard of JIS (Japan Industrial Standards) is not included. The thickness of the lid body 60 may vary depending on the part of the lid body 60. When the thickness of the lid body 60 varies depending on the part, the thickness of the lid body 60 is the thickness of the thickest part.

[0041] The lid seal portion 63 further includes boundaries 64, 65, 66, and 67. The boundary 64 is a boundary between the first seal surface 63A and the second seal surface 63B. The boundary 65 is a boundary between the first seal surface 63A and the third seal surface 63C. The boundary 66 is a boundary between the fourth seal surface 63D and the second seal surface 63B. The boundary 67 is a boundary between the fourth seal surface 63D and the third seal surface 63C. The shapes of the boundaries 64 to 67 may be angular, or may be rounded by performing R processing. In this embodiment, the boundaries 64 to 67 are angular.

[0042] In this embodiment, the lid body 60 is made up of a resin material. Here, "made up of a resin material" means that, when the entire material constituting the lid body 60 is taken as 100% by mass, the content of the resin material is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In other words, the material constituting the lid body 60 can contain materials other than the resin material in addition to the resin material.

[0043] Specific examples of the resin include thermoplastic resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenol resin, and modified products of these resins. The resin material may be a mixture of these resins, a copolymer, or a modified product of the copolymer. 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 lid 60 may be molded by any molding method.

[0044] Specific examples of polyesters include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolymerized polyesters. Examples of copolymerized polyesters include copolymerized polyesters in which ethylene terephthalate is the main repeating unit. Specific examples of polyesters include copolymerized polyesters in which ethylene terephthalate is the main repeating unit and is polymerized with ethylene isophthalate (hereinafter abbreviated as polyethylene (terephthalate / isophthalate)), polyethylene (terephthalate / adipate), polyethylene (terephthalate / sodium sulfoisophthalate), polyethylene (terephthalate / sodium isophthalate), polyethylene (terephthalate / phenyl-dicarboxylate), and polyethylene (terephthalate / decane dicarboxylate). Of these, the resin material is preferably polybutylene terephthalate from the viewpoint of increasing heat resistance and pressure resistance.

[0045] Specific examples of polyolefins include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and ethylene-butene-propylene terpolymers. When the polyolefin resin is a copolymer, it may be a block copolymer or a random copolymer. Among these, polypropylene is preferred as the resin material because it has excellent heat fusion properties and electrolyte resistance.

[0046] The resin as the resin material may contain a filler as necessary. Specific examples of the filler include glass beads, graphite, glass fiber, and carbon fiber. When the resin as the resin material contains the filler, the deformation resistance of the lid body 60 against temperature changes can be improved.

[0047] The melt mass flow rate of the resin material contained in the material constituting the lid body 60 is preferably within the range of 1 g / 10 min to 80 g / 10 min, and more preferably within the range of 5 g / 10 min to 60 g / 10 min. The melt mass flow rate is measured based on JIS K7210-1:2014.

[0048] In another example, the lid body 60 may be configured to include a metal material. Here, "configured to include a metal material" means that, when the entire material constituting the lid body 60 is taken as 100% by mass, the content of the metal material is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. That is, the material constituting the lid body 60 may contain materials other than the metal material in addition to the metal material. The metal material constituting the lid body 60 can be selected arbitrarily. The metal material constituting the lid body 60 is, for example, aluminum, aluminum alloy, nickel, copper, copper alloy, or stainless steel. Specific examples of austenitic stainless steel constituting stainless steel include SUS304, SUS301, and SUS316L. For example, when the electrode body 20 is a lithium ion battery, the lid body 60 connected to the positive electrode is preferably configured to include aluminum or an aluminum alloy. The lid body 60 connected to the negative electrode is preferably configured to include nickel, copper, or a copper alloy. The material constituting the lid body 60 connected to the negative electrode may be copper plated with nickel. The material constituting the lid body 60 may contain recycled metal materials. When the lid body 60 is constituted by containing a metal material, the joining surface of the lid body 60 that is joined to the resin material may be provided with a corrosion-resistant coating from the viewpoint of suppressing dissolution and corrosion.

[0049] In this embodiment, the lid body 60 is formed with a through hole 60X 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 stored, the electrode terminal 30 protrudes to the outside of the exterior body 40 through the through hole 60X formed in the lid body 60. A small gap between the through hole 60X of the lid body 60 and the electrode terminal 30 is filled with, for example, resin. Note that, in the electricity storage device 10, the position from which the electrode terminal 30 protrudes to the outside can be arbitrarily selected. For example, the electrode terminal 30 may protrude to the outside from a hole formed in any one of the six surfaces of the exterior body 40. In this case, a small gap between the exterior body 40 and the electrode terminal 30 is filled with, for example, resin. In the electricity storage device 10, the lid body 60 and the electrode terminal 30 are provided as separate bodies, but the lid body 60 and the electrode terminal 30 may be formed integrally. If the electrode terminals 30 do not protrude from the edge of the exterior body 40, the lid body 60 does not need to have the through-holes 60X formed therein.

[0050] In this embodiment, in a state in which the exterior film 50 is wrapped around the electrode body 20 so as to have the opening 40A, the surfaces (thermal adhesive resin layer 53) of the exterior film 50 in the protruding portion 50Y that face each other are heat-sealed to form the first sealed portion 70. In this embodiment, the surfaces (thermal adhesive resin layer 53) of the exterior film 50 in the protruding portion 50Y that face each other are entirely heat-sealed to form the first sealed portion 70.

[0051] The first sealing portion 70 includes a portion where the first edge 50A and the second edge 50B of the exterior film 50 shown in FIG. 4 are overlapped. The first sealing portion 70 extends in the longitudinal direction (FB direction) of the exterior body 40. The position where the first sealing portion 70 is formed in the exterior body 40 can be selected arbitrarily. In the present embodiment, the base 70X of the first sealing portion 70 is preferably located on the side 43 at the boundary between the first surface 41A and the second surface 42A of the exterior body 40. The base 70X of the first sealing portion 70 may be located on any surface of the exterior body 40. From the viewpoint of configuring the power storage device 10 in a small size, it is preferable that the protruding portion 50Y is folded, for example, onto the first surface 41A or the second surface 42A of the exterior body 40 when the power storage device 10 is used. In this embodiment, as shown in FIG. 5, the protruding portion 50Y is folded toward the second surface 42A of the exterior body 40 when the electricity accumulation device 10 is in use.

[0052] In this embodiment, the second sealed portion 80 is formed by heat-sealing the heat-sealable resin layer 53 of the exterior film 50 and the lid seal portion 63 of the lid body 60. The second sealed portion 80 has a second long side sealed portion 81 and a second short side sealed portion 82 (see FIG. 17 for both). The second long side sealed portion 81 is a portion where the heat-sealable resin layer 53 of the exterior film 50 is sealed to the first seal surface 63A and the fourth seal surface 63D of the lid body 60. The second short side sealed portion 82 is a portion where the heat-sealable resin layer 53 of the exterior film 50 is sealed to the second seal surface 63B and the third seal surface 63C of the lid body 60.

[0053] Hereinafter, the seal strength between the heat-fusible resin layer 53 of the exterior film 50 and the lid seal portion 63 of the lid 60 may be referred to as the seal strength of the second sealing portion 80. The seal strength of the second sealing portion 80 is the seal strength between the heat-fusible resin layer 53 and the lid 60 at the second long side seal portion 81, i.e., the lid seal portion 63 extending in the LR (width) direction in FIG. 1A.

[0054] The seal strength of the second sealing portion 80 is measured as follows. First, a cut is made in a portion of the exterior film 50 that constitutes the first surface 41 of the exterior body 40, and three strip-shaped members 41X, 41Y, and 41Z (see the two-dot chain line in FIG. 1B) arranged in the LR direction are formed. The width of the three strip-shaped members 41X, 41Y, and 41Z in the LR direction is 15 mm. The ends of the strip-shaped members 41X, 41Y, and 41Z are joined to the lid body 60 at the second sealing portion 80. The length of the lid body 60 in the LR direction is 45 mm or more. Next, the end of the strip-shaped members 41X, 41Y, and 41Z opposite to the end joined to the lid body 60 is pulled upward in the UD direction (the direction opposite to the first surface 41B) to measure the seal strength of each of the strip-shaped members 41X, 41Y, and 41Z. In this embodiment, the seal strength of the second sealing portion 80 is the average value of the seal strengths of the strip members 41X, 41Y, and 41Z. When the length of the lid body 60 in the LR direction is less than 45 mm, three strip members of an arbitrary width X mm less than 15 mm are formed, and the seal strengths of the three strip members are measured in the same manner as when the length of the lid body 60 in the LR direction is 45 mm or more. The obtained seal strengths are divided by the arbitrary width X mm and multiplied by 15 to convert them into the seal strengths of the three strip members in a width of 15 mm. The seal strength of the second sealing portion 80 is the average value of the seal strengths of the three strip members converted into a width of 15 mm. In addition, when the lid body 60 is divided into multiple parts including long sides and short sides, the seal strength of the second sealing portion 80 is the seal strength of the long side portion of the lid seal portion 63 of the multiple parts.

[0055] From the viewpoint of suitably maintaining the state in which the electrode body 20 is sealed by the exterior body 40, the seal strength of the second sealing portion 80 is preferably 40N / 15mm or more, more preferably 50N / 15mm or more, more preferably 60N / 15mm or more, more preferably 70N / 15mm or more, and more preferably 85N / 15mm or more. When the seal strength of the second sealing portion 80 is 40N / 15mm or more, the state in which the electrode body 20 is sealed by the exterior body 40 is suitably maintained even if the electricity storage device 10 is used for, for example, several years (less than 10 years). When the seal strength of the second sealing portion 80 is 85N / 15mm or more, the state in which the electrode body 20 is sealed by the exterior body 40 is suitably maintained even if the electricity storage device 10 is used for, for example, 10 years or more. The seal strength of the second sealing portion 80 is preferably 300N / 15mm or less. A preferred range of the seal strength of the second sealing portion 80 is 40N / 15mm to 300N / 15mm, 50N / 15mm to 300N / 15mm, 60N / 15mm to 300N / 15mm, 70N / 15mm to 300N / 15mm, or 85N / 15mm to 300N / 15mm.

[0056] Since the overhanging portion 50Y can move relative to the main body portion 50X, material fatigue is likely to occur in the overhanging portion 50Y, particularly in a portion including the root 70X of the first sealing portion 70. In the portion of the exterior film 50 where material fatigue occurs, the barrier layer 52, the base material layer 51, and the heat-sealable resin layer 53 may peel off, causing cracks and damaging the exterior film 50. In a typical example, the electricity storage device 10 may be moved to an arbitrary location while the overhanging portion 50Y (first sealing portion 70) is being held. In such a case, since the overhanging portion 50Y can move relative to the main body portion 50X, the portion of the exterior film 50 including the root of the overhanging portion 50Y, in other words, the portion including the root 70X of the first sealing portion 70, may be damaged, and the sealing performance of the electricity storage device 10 may be reduced.

[0057] In addition, in a manufacturing process of the electricity storage device 10 described below, a portion of the exterior film 50 that constitutes the protruding portion 50Y may be expanded and an electrolyte may be injected. This may damage a portion of the exterior film 50 that includes the base of the protruding portion 50Y, in other words, a portion where the base 70X of the first sealing portion 70 is to be formed, and the sealing performance of the electricity storage device 10 may be reduced.

[0058] In this embodiment, a fixing jig 100 that prevents the extension portion 50Y from moving relative to the main body portion 50X is attached to at least one of the finished electricity storage device 10 and an unfinished electricity storage device (hereinafter referred to as an "intermediate body 10Z").

[0059] Fig. 6 is a perspective view of the completed electricity storage device 10 with the fixing jig 100 attached. Fig. 7 is a perspective view of the fixing jig 100 of Fig. 6.

[0060] 6, in this embodiment, the fixing jig 100 is attached to both ends of the protruding portion 50Y in the FB direction in the completed power storage device 10. The fixing jig 100 may be attached to only one end of the protruding portion 50Y in the FB direction.

[0061] The material constituting the fixing jig 100 can be selected arbitrarily. The material constituting the fixing jig 100 is, for example, a resin material, a metal material, a rubber material, a metal oxide, or a carbon material. The fixing jig 100 has a first fixing portion 110, a second fixing portion 120, and a connecting portion 130. The material constituting the first fixing portion 110, the material constituting the second fixing portion 120, and the material constituting the connecting portion 130 may be the same material or different materials. The first fixing portion 110, the second fixing portion 120, and the connecting portion 130 may be integrally formed, or may be formed separately and joined. In this embodiment, the first fixing portion 110, the second fixing portion 120, and the connecting portion 130 are integrally formed, for example, by a resin material.

[0062] The first fixing portion 110 is plate-shaped and is disposed so as to straddle the first surface 50YA of the protruding portion 50Y and the first surface 41A of the exterior body 40. The first fixing portion 110 contacts the first surface 50YA of the protruding portion 50Y and the first surface 41A of the exterior body 40. The first fixing portion 110 suppresses the protruding portion 50Y from moving toward the first surface 41A around the base 70X of the first sealing portion 70. At least a part of the first fixing portion 110 may or may not be joined to the first surface 50YA of the protruding portion 50Y and the first surface 41A of the exterior body 40. The first fixing portion 110 can be joined to the first surface 50YA of the protruding portion 50Y and the first surface 41A of the exterior body 40 by any means, such as an adhesive or heat seal. In this embodiment, the first fixing portion 110 is not joined to the first surface 50YA of the protruding portion 50Y and the first surface 41A of the exterior body 40.

[0063] The second fixing portion 120 is plate-shaped and is arranged so as to contact the second surface 50YB of the overhang portion 50Y. The second fixing portion 120 supports the overhang portion 50Y, thereby suppressing the overhang portion 50Y from moving toward the second surface 42A around the base 70X of the first sealing portion 70. At least a part of the second fixing portion 120 may or may not be joined to the second surface 50YB of the overhang portion 50Y. The second fixing portion 120 can be joined to the second surface 50YB of the overhang portion 50Y by any means, such as an adhesive or heat seal. In this embodiment, the second fixing portion 120 is not joined to the second surface 50YB of the overhang portion 50Y.

[0064] The lengths of the first fixed portion 110 and the second fixed portion 120 in the FB direction can be selected arbitrarily. In this embodiment, the length of the first fixed portion 110 in the FB direction is longer than the length of the second fixed portion 120. In the FB direction, the length of the first fixed portion 110 may be shorter than the length of the second fixed portion 120 or may be the same as the length of the second fixed portion 120.

[0065] The connection portion 130 connects the first fixing portion 110 and the second fixing portion 120. The connection portion 130 may or may not be in contact with the side surface 50YC of the overhanging portion 50Y. In this embodiment, the connection portion 130 is in contact with the side surface 50YC of the overhanging portion 50Y. At least a part of the connection portion 130 may or may not be joined to the side surface 50YC of the overhanging portion 50Y. The connection portion 130 can be joined to the side surface 50YC of the overhanging portion 50Y by any means, such as, for example, an adhesive or heat sealing. In this embodiment, the connection portion 130 is not joined to the side surface 50YC of the overhanging portion 50Y.

[0066] In the electricity storage device 10, the internal pressure of the electricity storage device 10 may increase due to volumetric changes in the positive electrode active material and negative electrode active material of the electrode body 20 accompanying charging and discharging, and due to gas generation, etc. When the internal pressure of the electricity storage device 10 increases, the exterior body 40 expands, causing the exterior film 50 to stretch, which may reduce the mechanical strength of the exterior film 50. The fixing jig 100 also has the effect of suppressing expansion of the exterior body 40, particularly the first surface 41A and the second surface 42A, when the internal pressure of the electricity storage device 10 increases.

[0067] The fixing jig 100 also has the effect of suppressing peeling of the first sealing portion 70 and the second sealing portion 80 when the internal pressure of the exterior body 40 increases. The larger the contact area between the first fixing portion 110 and the first surface 41A and the first surface 50YA, the greater the effect of the fixing jig 100 in suppressing peeling of the first sealing portion 70 and the second sealing portion 80. The larger the contact area between the second fixing portion 120 and the connection portion 130 and the second surface 42A, the greater the effect of the fixing jig 100 in suppressing peeling of the second sealing portion 80 (particularly the second short side seal portion 82).

[0068] When a vacuum is drawn in the manufacturing process of the electricity storage device 10, the exterior body 40 may shrink. When at least a portion of the fixing jig 100 is joined to any surface of the exterior body 40, the fixing jig 100 can suppress the exterior body 40 from shrinking.

[0069] In the manufacturing process of the electricity storage device 10, a predetermined area including the root 70X of the first sealing portion 70 is heat-sealed multiple times, and thus is significantly damaged. The heat-sealable resin layer 53 of the exterior film 50 is thin at the root 70X of the first sealing portion 70. For this reason, when the protruding portion 50Y is folded toward the first surface 41A or the second surface 42A from the viewpoint of miniaturization of the electricity storage device 10, the barrier layer 52, the base material layer 51, and the heat-sealable resin layer 53 may peel off at the portion including the root 70X of the first sealing portion 70, and a crack may occur in the exterior film 50. If a crack occurs in the portion of the exterior film 50 including the root 70X, the sealing property of the exterior body 40 may be reduced, and for example, an electrolyte solution or the like may leak. In this embodiment, in order to increase the strength of base 70X and its surroundings, first sealing portion 70 includes a portion (hereinafter, "thickness portion 90") whose thickness HA increases toward base 70X.

[0070] FIG. 8 is a front view of the power storage device 10 in FIG. 5 before the overhanging portion 50Y of the power storage device 10 is folded. The film thickness portion 90 includes a starting point 90A and an end point 90B that is farther away from the root 70X than the starting point 90A. In this embodiment, the starting point 90A is located outside the surface of the exterior film 50 in the second sealing portion 80. The thickness HA of the first sealing portion 70 becomes locally larger at the starting point 90A as it moves outward from the overhanging portion 50Y. The thickness HA of the first sealing portion 70 becomes locally smaller at the end point 90B as it moves outward from the overhanging portion 50Y. The power storage device 10 can fold the overhanging portion 50Y at the end point 90B toward the first surface 41A or the second surface 42A. In another example, the overhanging portion 50Y can be folded starting from any point between the end point 90B and the starting point 90A. The overhanging portion 50Y is folded at a position away from the root 70X, in other words, at a position where damage caused by heat sealing is relatively small, so that the occurrence of cracks in the exterior film 50 at the root 70X is suppressed. From the viewpoint of suppressing the occurrence of cracks in the exterior film 50, it is preferable that the overhanging portion 50Y is folded at a position 0.1 mm or more away from the root 70X. In addition, from the viewpoint of making it easy to grasp the folding position of the first sealing portion 70, it is preferable that a crease 90C is formed in advance at the end point 90B or between the start point 90A and the end point 90B. It is preferable that the crease 90C is formed in the overhanging portion 50Y over almost the entire area in the FB direction. It is preferable that the crease 90C is formed at a position 0.1 mm or more away from the root 70X in the LR direction. From the viewpoint of easily folding the overhanging portion 50Y, it is preferable that the crease 90C is formed by a slit 90CX that does not penetrate the exterior film 50. In another example, the crease 90C may be formed by applying an additional seal to the exterior film 50.

[0071] In the completed power storage device 10, when an external force is applied to the overhanging portion 50Y in a state where the overhanging portion 50Y is folded at a position away from the base 70X, the overhanging portion 50Y may be folded from the base 70X. In the completed power storage device 10, in order to maintain the state where the overhanging portion 50Y is folded at a position away from the base 70X, it is preferable that the fixing jig 200 is disposed at least in the gap 50Z between the overhanging portion 50Y and the main body portion 50X. The gap 50Z is formed between the second surface 50YB of the overhanging portion 50Y and the second surface 42B of the exterior body 40. When the overhanging portion 50Y is folded toward the first surface 41A, the gap 50Z is formed between the first surface 50YA of the overhanging portion 50Y and the first surface 41A of the exterior body 40. For this reason, it is preferable that the fixing jig 200 is disposed at least in the gap between the first surface 50YA and the first surface 41A.

[0072] Fig. 9 is a front view of the completed electricity storage device 10 in a state in which the fixing jig 200 is arranged. Fig. 10 is a perspective view of the fixing jig 200 of Fig. 9. In this embodiment, the fixing jig 200 is attached to both ends of the overhanging portion 50Y in the FB direction. The fixing jig 200 may be attached to only one end of the overhanging portion 50Y in the FB direction. Note that instead of at least one of the fixing jigs 200 attached to both ends of the overhanging portion 50Y in the FB direction, the fixing jig 100 shown in Fig. 6 may be attached to the completed electricity storage device 10.

[0073] The material constituting the fixing jig 200 can be selected arbitrarily. The material constituting the fixing jig 200 is, for example, a resin material, a metal material, a rubber material, a metal oxide, or a carbon material. The fixing jig 200 has a first fixing portion 110, a coupling portion 220, and a connection portion 230. The material constituting the first fixing portion 210, the material constituting the coupling portion 220, and the material constituting the connection portion 230 may be the same material or different materials. The first fixing portion 210, the coupling portion 220, and the connection portion 230 may be integrally formed, or may be formed separately and joined. In this embodiment, the first fixing portion 210, the coupling portion 220, and the connection portion 230 are integrally formed, for example, by a resin material.

[0074] The first fixing portion 210 is plate-shaped and is inserted into the gap 50Z between the overhang portion 50Y and the main body portion 50X. The first fixing portion 210 may or may not be in contact with the second surface 50YB of the overhang portion 50Y and the second surface 42A of the exterior body 40. In this embodiment, the first fixing portion 210 is in contact with the second surface 50YB of the overhang portion 50Y and the second surface 42A of the exterior body 40. The first fixing portion 210 suppresses the overhang portion 50Y from moving toward the second surface 42A around the base 70X of the first sealing portion 70. At least a portion of the first fixing portion 210 may or may not be joined to the second surface 50YB of the overhang portion 50Y and the second surface 42A of the exterior body 40. The first fixing portion 210 can be joined to the second surface 50YB of the protruding portion 50Y and the second surface 42A of the exterior body 40 by any means, such as an adhesive or heat sealing. In this embodiment, the first fixing portion 210 is not joined to the second surface 50YB of the protruding portion 50Y and the second surface 42A of the exterior body 40.

[0075] The length of the first fixing portion 210 in the FB direction can be selected arbitrarily. In this embodiment, the length of the first fixing portion 210 in the FB direction is shorter than the length of the overhanging portion 50Y. The length of the first fixing portion 210 in the FB direction may be longer than the length of the overhanging portion 50Y or may be the same as the length of the overhanging portion 50Y.

[0076] The connecting part 220 is connected to the lid body 60. In this embodiment, the connecting part 220 is a hollow box having a recess 220A. The fixing jig 200 and the lid body 60 are connected by inserting a protrusion 62A formed at an arbitrary position on the second surface 62 of the lid body 60 into the recess 220A. The connecting part 220 may have a protrusion. The fixing jig 200 and the lid body 60 may be connected by inserting a protrusion of the connecting part 220 into a recess formed at an arbitrary position on the second surface 62 of the lid body 60. The connecting part 220 is preferably made of a material softer than the material constituting the first fixing part 210 and the connecting part 230 so that the connecting part 220 can be easily connected to the protrusion or recess formed on the lid body 60.

[0077] The connecting portion 230 is, for example, in the form of a plate, and connects the first fixing portion 210 and the coupling portion 220 together.

[0078] Like fixing jig 100, fixing jig 200 has the effect of suppressing expansion of exterior body 40 and suppressing peeling of first sealing portion 70 and second sealing portion 80. When at least a portion of fixing jig 200 is joined to any surface of exterior body 40, an effect of suppressing contraction of exterior body 40 is obtained.

[0079] <1-2. Manufacturing method of electricity storage device> 11 is a flowchart showing an example of a method for manufacturing the power storage device 10. The method for manufacturing the power storage device 10 includes, for example, a first step, a second step, a third step, a fourth step, a fifth step, a sixth step, a seventh step, an eighth step, a ninth step, a tenth step, and an eleventh step. The first step to the eleventh step are performed, for example, by a manufacturing device for the power storage device 10. Note that the first step to the eleventh step are merely names of the steps in the method for manufacturing the power storage device 10 defined for the sake of convenience, and do not necessarily refer to the order of the steps. The order of the following steps can be changed as desired.

[0080] In the first step of step S11, the manufacturing equipment places a lid body 60 (hereinafter referred to as a "lid unit 60Z") with electrode terminals 30 attached to both ends of the electrode body 20. Completion of the first step electrically connects the electrode terminals 30 and the electrodes of the electrode body 20. Note that in the first step, the lid body 60 may be connected to the electrode terminals 30 electrically connected to the electrode body 20.

[0081] The second step (packaging step) of step S12 is performed after the first step. In the second step, the manufacturing device wraps the electrode body 20 with the exterior film 50 so that the main body 50X and the overhanging portion 50Y are formed. As described later, since the overhanging portion 50Y has a function as a gas pocket 300, the overhanging portion 50Y formed in the second step has a larger area in a plan view than the overhanging portion 50Y of the completed power storage device 10. In other words, in the second step, in order to form the gas pocket 300, an exterior film 50 having a larger area than the exterior film 50 of the completed power storage device 10 is used. In the second step, the manufacturing device winds the exterior film 50 around the electrode body 20 and the lid body 60 with tension acting on the exterior film 50 while restricting the movement of the electrode body 20 and the lid body 60 by the restricting means. The restricting means is, for example, a groove into which the electrode body 20 and the lid body 60 are fitted. The regulating means may be a device that applies an external force to the electrode body 20 and the lid body 60 so as to prevent the electrode body 20 and the lid body 60 from moving. The regulating means may be a device that applies a force to the electrode body 20 and the lid body 60 in a direction opposite to the direction in which the exterior film 50 is pulled. The regulating means may include a roller that runs on the exterior film 50 while the exterior film 50 is being pulled in order to remove wrinkles in the exterior film 50.

[0082] The third step of step S13 is performed after the second step. As shown in Fig. 12, in the third step, the manufacturing device forms the first FB direction seal portion 71 having an unsealed portion 71Z in the center. Note that the hatched portion in Fig. 8 shows an example of the region where the first FB direction seal portion 71 is formed.

[0083] The fourth step of step S14 is performed after the third step. As shown in FIG. 13, in the fourth step, the manufacturing apparatus forms the second short side seal portion 82. As shown in FIG. 14, in the fourth step, the manufacturing apparatus preferably forms the second short side seal portion 82, for example, so that the seal bar 410 does not contact the film thickness portion 90. In another example of the fourth step, as shown in FIG. 15, the manufacturing apparatus preferably forms the second short side seal portion 82 using a seal bar 410X having a seal surface 410XA and a seal surface 410XB. The seal surface 410XA is a seal surface shaped along the second seal surface 63B and the third seal surface 63C. The seal surface 410XB is a seal surface shaped along the contour of the film thickness portion 90. The hatched portion in FIG. 13 shows an example of an area where the second short side seal portion 82 is formed.

[0084] The fifth step of step S15 is performed after the fourth step. As shown in FIG. 16, in the fifth step, the manufacturing equipment forms the second long side seal portion 81 so that the thickness HA of the thickness portion 90 is maintained. As shown in FIG. 14, in the fifth step, the manufacturing equipment forms the second long side seal portion 81, for example, so that the seal bar 410 does not come into contact with the thickness portion 90. Note that the hatched portion in FIG. 16 shows an example of the region where the second long side seal portion 81 is formed.

[0085] The sixth step of step S16 is performed after the fifth step. As shown in FIG. 17, in the sixth step, the manufacturing apparatus forms the first LR seal portion 72. In the sixth step, the first LR seal portion 72 is formed so as to overlap partially with the first FB seal portion 71 in a portion including the side 43. Note that the hatched portion in FIG. 17 shows an example of an area where the first LR seal portion 72 is formed. Completion of the sixth step results in the completion of a gas pocket 300 having a larger area in a plan view than the protruding portion 50Y of the completed electricity storage device 10.

[0086] The seventh step (jig placement step) of step S17 is performed after the sixth step. The seventh step may be performed at any timing after the second step. As shown in Fig. 18, in the seventh step, the manufacturing apparatus places the fixing jig 100 at both ends of the protruding portion 50Y in the FB direction. The seventh step may be performed by an operator.

[0087] The eighth step of step S18 is performed after the seventh step. In the eighth step, the manufacturing device injects an electrolyte through the opening of the gas pocket 300. As shown in FIG. 19, after the electrolyte is injected, the gas pocket 300 is bonded at the edge including the opening to form a pocket sealing portion 310. After the eighth step, an aging step is performed. Gas generated by the aging step is stored in the gas pocket 300. The gas stored in the gas pocket 300 is discharged through an opening formed by cutting a part of the gas pocket 300. The gas pocket 300 is cut, for example, along the dashed line XA shown in FIG. 19 to form an opening for discharging the gas.

[0088] The ninth step of step S19 is performed after the eighth step and after the aging step is completed. In the ninth step, the manufacturing apparatus forms the first sealing portion 70. In the ninth step, the first FB direction seal portion 71 may or may not be resealed.

[0089] The tenth step (jig placement step) of step S20 is performed after the ninth step. In the tenth step, the manufacturing device places the fixing jig 200, instead of the fixing jig 100, at both ends of the protruding portion 50Y in the FB direction. The tenth step may be performed by an operator. The step S20 may be omitted, and the fixing jig 100 placed in step S17 may be used as is.

[0090] The 11th step of step S21 is performed after the 10th step. In the 11th step, the manufacturing apparatus folds the protruding portion 50Y including the first sealing portion 70. The 11th step may be performed before the 10th step. That is, the fixing jig 200 may be placed after the protruding portion 50Y including the first sealing portion 70 is folded. The 11th step may be performed by an operator.

[0091] <1-3. Actions and Effects of Electricity Storage Devices> According to the electricity storage device 10, the fixing jigs 100 and 200 are provided, which prevents the protruding portion 50Y from moving relative to the main body portion 50X. The portion of the exterior film 50 that constitutes the protruding portion 50Y is prevented from being damaged, so that the electricity storage device 10 has high sealing performance.

[0092] [2. Modifications] The above-described embodiments are examples of possible forms of the electricity storage device, the fixing jig, and the manufacturing method of the electricity storage device according to the present invention, and are not intended to limit the forms. The electricity storage device, the fixing jig, and the manufacturing method of the electricity storage device according to the present invention may take forms different from those exemplified in the embodiments. One example is a form in which a part of the configuration of the embodiment is replaced, changed, or omitted, or a form in which a new configuration is added to the embodiment. Below, several examples of modified embodiments are shown. Note that the following modified examples can be combined with each other as long as there is no technical contradiction.

[0093] <2-1> In the above embodiment, the specific configuration of the fixing jig 100 can be changed as desired as long as the configuration can suppress the movement of the overhanging portion 50Y relative to the main body portion 50X. For example, the fixing jig 100 may include at least the first fixing portion 110 or the second fixing portion 120. When the fixing jig 100 is configured only by the first fixing portion 110, it is preferable that the first fixing portion 110 is joined to at least a part of the first surface 41A of the exterior body 40 and the first surface 50YA of the overhanging portion 50Y by adhesive, heat sealing, or the like. When the fixing jig 100 is configured only by the second fixing portion 120, the second fixing portion 120 is joined to at least a part of the second surface 42A of the exterior body 40 and the second surface 50YB of the overhanging portion 50Y by adhesive, heat sealing, or the like.

[0094] FIG. 20 is a perspective view of a fixing jig 100X of a modified example. The fixing jig 100X includes a first fixing portion 110X, a pair of second fixing portions 120X, and a pair of connecting portions 130X. The first fixing portion 110X is plate-shaped and extends in the FB direction. The length of the first fixing portion 110X in the FB direction is substantially equal to the length of the protruding portion 50Y. The pair of second fixing portions 120X are plate-shaped and connected to the ends of the first fixing portion 110X in the FB direction via a pair of connecting portions 130. The length of the pair of second fixing portions 120X in the FB direction is shorter than the length of the protruding portion 50Y. The fixing jig 100X, like the fixing jig 100, has the effect of suppressing the expansion of the exterior body 40 and the effect of suppressing the peeling of the first sealing portion 70 and the second sealing portion 80. When at least a portion of the fixing jig 100X is joined to any surface of the exterior body 40, it is possible to obtain an effect of suppressing shrinkage of the exterior body 40. Since the length of the first fixing portion 110X in the FB direction is substantially equal to the length of the protruding portion 50Y, the fixing jig 100X is particularly effective in suppressing peeling of the first sealing portion 70.

[0095] FIG. 21 is a perspective view of a fixing jig 100Y of another modified example. The fixing jig 100Y includes a first fixing portion 110Y, a second fixing portion 120Y, and a pair of connecting portions 130Y. The first fixing portion 110Y is plate-shaped and extends in the FB direction. The length of the first fixing portion 110Y in the FB direction is substantially equal to the length of the protruding portion 50Y. The second fixing portion 120Y is plate-shaped and extends in the FB direction. The length of the second fixing portion 120Y in the FB direction is substantially equal to the length of the protruding portion 50Y. The pair of connecting portions 130Y connect the end of the first fixing portion 110Y and the end of the second fixing portion 120Y in the FB direction. The fixing jig 100Y, like the fixing jig 100, has the effect of suppressing the expansion of the exterior body 40 and the effect of suppressing the peeling of the first sealing portion 70 and the second sealing portion 80. When at least a portion of the fixing jig 100Y is joined to any surface of the exterior body 40, the effect of suppressing contraction of the exterior body 40 can be obtained. Since the fixing jig 100Y sandwiches the first sealing portion 70 between the first fixing portion 110Y and the second fixing portion 120Y, the effect of suppressing peeling of the first sealing portion 70 is particularly high. Furthermore, the fixing jig 100Y can more effectively suppress expansion of the second surface 42A as the contact area between the connection portion 130Y and the second surface 42A becomes larger.

[0096] FIG. 22 is a perspective view of an electricity storage device 10 including a fixing jig 100Z of yet another modified example. The fixing jig 100Z includes a first fixing portion 110Z, a second fixing portion 120Z, a connecting portion 130Z, and a coupling portion 140Z. The first fixing portion 110Z has a similar configuration to the first fixing portion 110 of the fixing jig 100 of the embodiment. The second fixing portion 120Z has a similar configuration to the second fixing portion 120 of the fixing jig 100 of the embodiment. The coupling portion 130Z has a similar configuration to the coupling portion 130 of the fixing jig 100 of the embodiment. The coupling portion 140Z is connected to the first fixing portion 110Z and is coupled to the lid body 60. In this modified example, the coupling portion 140Z is a hollow box having a recess 140A. The fixing jig 140 and the lid body 60 are connected by inserting the convex portion 62A formed at an arbitrary position on the second surface 62 of the lid body 60 into the concave portion 140A. The connecting portion 140Z may have a convex portion. The fixing jig 100Z and the lid body 60 may be connected by inserting the convex portion of the connecting portion 140Z into the concave portion formed at an arbitrary position on the second surface 62 of the lid body 60. The connecting portion 140Z is preferably made of a material softer than the material constituting the first fixing portion 110Z and the connecting portion 130Z so that the connecting portion 140Z can be easily connected to the convex portion or the concave portion formed on the lid body 60. According to the fixing jig 100Z, since the connecting portion 140Z connects the extension portion 50Y and the lid body 60, for example, when the electricity storage device 10 is moved to an arbitrary location while the fixing jig 100Z is held, the tensile force acting on the extension portion 50Y can be reduced. For this reason, the portion of the exterior film 50 that constitutes the protruding portion 50Y is less likely to be damaged. Like the fixing jig 100, the fixing jig 100Z has the effect of suppressing expansion of the exterior body 40 and suppressing peeling of the first sealing portion 70 and the second sealing portion 80. When at least a portion of the fixing jig 100Z is joined to any surface of the exterior body 40, the effect of suppressing contraction of the exterior body 40 is obtained.

[0097] 23 is a perspective view of an electricity storage device 10 including a fixing jig 500 according to yet another modified example. The fixing jig 500 has a frame shape that surrounds the lid body 60. The fixing jig 500 may or may not be joined to the exterior body 40. The fixing jig 500 has an upper frame 510, a lower frame 520, and a pair of side frames 530A, 530B.

[0098] The top frame 510 contacts the first surface 41A of the exterior body 40. The top frame 510 extends in the LR direction. The length of the top frame 510 in the LR direction is longer than that of the main body 50X. Therefore, one end 510X of the top frame 510 in the LR direction straddles the first surface 41A of the exterior body 40 and the first surface 50YA of the protruding portion 50Y.

[0099] The lower frame 520 contacts the first surface 41B of the exterior body 40. The lower frame 520 extends in the LR direction. The length of the lower frame 520 in the LR direction is slightly longer than that of the main body 50X.

[0100] The side frame 530A extends in the UD direction. The side frame 530A contacts the second surface 42A of the exterior body 40. The side frame 530A is connected to one end of the lower frame 520 in the LR direction. The side frame 530B extends in the UD direction. The side frame 530B contacts the second surface 42B of the exterior body 40. The side frame 530B is connected to the other end of the lower frame 520 and the other end of the upper frame 510 in the LR direction.

[0101] The fixing jig 500, like the fixing jig 100, has the effect of suppressing the expansion of the exterior body 40 and the effect of suppressing the first sealing portion 70 and the second sealing portion 80 from peeling off. When at least a part of the fixing jig 500 is joined to any surface of the exterior body 40, the effect of suppressing the contraction of the exterior body 40 is obtained. Since the fixing jig 500 has a frame shape surrounding the lid body 60, it is particularly effective in suppressing the second sealing portion 80 from peeling off. The fixing jig 500 can more effectively suppress the expansion of the exterior body 40 as the lengths in the FB direction of the upper surface frame 510, the lower surface frame 520, and the pair of side surface frames 530A and 530B are longer.

[0102] <2-2> In the above embodiment, it is possible to arbitrarily select the position of the base 70X of the first sealing portion 70. For example, as shown in FIGS. 24 to 27, the base 70X of the first sealing portion 70 may be located on the first surface 41A of the exterior body 40.

[0103] 24, a fixing jig 600 of a modified example is attached to the electricity accumulation device 10. The fixing jig 600 includes a base portion 610 and a pair of walls 620A, 620B.

[0104] The base 610 is plate-shaped and disposed on the first surface 41A. The base 610 may or may not be joined to the first surface 41A.

[0105] The pair of walls 620A, 620B are plate-shaped and rise from the base 610. The wall 620A prevents the projection 50Y from moving toward the first surface 41A on the second surface 42B side of the exterior body 40. The wall 620A may or may not be in contact with the first surface 50YA of the projection 50Y. When the wall 620A is in contact with the first surface 50YA of the projection 50Y, the wall 620A may or may not be joined to the first surface 50YA of the projection 50Y.

[0106] The wall portion 620B suppresses the movement of the protruding portion 50Y toward the first surface 41A on the second surface 42A side of the exterior body 40. The wall portion 620B may or may not be in contact with the second surface 50YB of the protruding portion 50Y. When the wall portion 620B is in contact with the second surface 50YB of the protruding portion 50Y, the wall portion 620B may or may not be joined to the second surface 50YB of the protruding portion 50Y. In the example shown in FIG. 24, one of the wall portion 620A and the wall portion 620B may be omitted. The fixing jig 600, like the fixing jig 100, has an effect of suppressing the expansion of the exterior body 40 and an effect of suppressing the peeling of the first sealing portion 70 and the second sealing portion 80. When at least a part of the fixing jig 600 is joined to any surface of the exterior body 40, an effect of suppressing the contraction of the exterior body 40 is obtained. Fixing jig 600 sandwiches first sealing portion 70 between a pair of walls 620A, 620B, and is therefore particularly effective in preventing first sealing portion 70 (particularly the portion including base 70X) from peeling off.

[0107] 25, a fixing jig 700 of a modified example is attached to the electricity storage device 10. The fixing jig 700 has a pair of fixing portions 710, 720. The pair of fixing portions 710, 720 are plate-shaped and disposed on the first surface 41A. The pair of fixing portions 710, 720 may or may not be joined to the first surface 41A.

[0108] The fixing portion 710 prevents the overhanging portion 50Y from moving toward the first surface 41A on the second surface 42B side of the exterior body 40. The fixing portion 710 may or may not be in contact with the first surface 50YA of the overhanging portion 50Y. When the fixing portion 710 is in contact with the first surface 50YA of the overhanging portion 50Y, the fixing portion 710 may or may not be joined to the first surface 50YA of the overhanging portion 50Y.

[0109] The fixing portion 720 suppresses the movement of the protruding portion 50Y toward the first surface 41A on the second surface 42A side of the exterior body 40. The fixing portion 720 may or may not be in contact with the second surface 50YB of the protruding portion 50Y. When the fixing portion 720 is in contact with the second surface 50YB of the protruding portion 50Y, the fixing portion 720 may or may not be joined to the second surface 50YB of the protruding portion 50Y. In the example shown in FIG. 25, one of the fixing portion 710 and the fixing portion 720 may be omitted, and the fixing portion 710 and the fixing portion 720 may be partially joined. The fixing jig 700, like the fixing jig 100, has the effect of suppressing the expansion of the exterior body 40 and the effect of suppressing the first sealing portion 70 and the second sealing portion 80 from peeling off. When at least a portion of the fixing jig 700 is joined to any surface of the exterior body 40, it is possible to obtain an effect of suppressing shrinkage of the exterior body 40. Since the fixing jig 700 sandwiches the first sealing portion 70 between a pair of fixing portions 710, 720, it is particularly effective in suppressing peeling of the first sealing portion 70 (especially the portion including the base 70X).

[0110] 26, a fixing jig 800 of a modified example is attached to the electricity accumulation device 10. The fixing jig 800 has a pair of wall portions 810, 820, a connection portion 830, and a pair of coupling portions 840, 850.

[0111] The pair of walls 810, 820 are plate-shaped and disposed on the first surface 41A. The pair of walls 810, 820 may or may not be joined to the first surface 41A.

[0112] The wall portion 810 prevents the overhang portion 50Y from moving toward the first surface 41A on the second surface 42B side of the exterior body 40. The wall portion 810 may or may not be in contact with the first surface 50YA of the overhang portion 50Y. When the wall portion 810 is in contact with the first surface 50YA of the overhang portion 50Y, the wall portion 810 may or may not be joined to the first surface 50YA of the overhang portion 50Y.

[0113] The wall portion 820 prevents the overhang portion 50Y from moving toward the first surface 41A on the second surface 42A side of the exterior body 40. The wall portion 820 may or may not be in contact with the second surface 50YB of the overhang portion 50Y. When the wall portion 820 is in contact with the second surface 50YB of the overhang portion 50Y, the wall portion 820 may or may not be joined to the second surface 50YB of the overhang portion 50Y. The connection portion 830 connects the wall portion 810 and the wall portion 820.

[0114] The connecting portion 840 is connected to the wall portion 810 and connected to the lid body 60. In the example shown in FIG. 26, the connecting portion 840 is a hollow box having a recess 840A. The fixing jig 800 and the lid body 60 are connected by inserting a protrusion 62A formed at an arbitrary position on the second surface 62 of the lid body 60 into the recess 840A. The connecting portion 840 may have a protrusion. The fixing jig 800 and the lid body 60 may be connected by inserting a protrusion of the connecting portion 840 into a recess formed at an arbitrary position on the second surface 62 of the lid body 60. The connecting portion 840 is preferably made of a material softer than the material constituting the pair of walls 810, 820 and the connecting portion 830 so that the connecting portion 840 can be easily connected to the protrusion or recess formed on the lid body 60.

[0115] The connecting portion 850 is connected to the wall portion 820 and connected to the lid body 60. In the example shown in FIG. 26, the connecting portion 850 is a hollow box having a recess 850A. The fixing jig 800 and the lid body 60 are connected by inserting a protrusion 62A formed at an arbitrary position on the second surface 62 of the lid body 60 into the recess 850A. The connecting portion 850 may have a protrusion. The fixing jig 800 and the lid body 60 may be connected by inserting a protrusion of the connecting portion 850 into a recess formed at an arbitrary position on the second surface 62 of the lid body 60. The connecting portion 850 is preferably made of a material softer than the material constituting the pair of walls 820, 820 and the connecting portion 830 so that the connecting portion 850 can be easily connected to the protrusion or recess formed on the lid body 60. In the example shown in FIG. 26, the wall 810 and the connecting portion 840, or the wall 820 and the connecting portion 850 may be omitted. As shown in FIG. 27, the connecting portion 830 may be omitted. According to the fixing jig 800, the protruding portion 50Y and the lid body 60 are connected by the connecting portions 840 and 850. Therefore, for example, when the electricity storage device 10 is moved to an arbitrary location while the fixing jig 800 is held, the pulling force acting on the protruding portion 50Y can be reduced. Therefore, the portion of the exterior film 50 that constitutes the protruding portion 50Y is less likely to be damaged. The fixing jig 800, like the fixing jig 100, has an effect of suppressing the expansion of the exterior body 40 and an effect of suppressing the peeling of the first sealing portion 70 and the second sealing portion 80. When at least a part of the fixing jig 800 is joined to an arbitrary surface of the exterior body 40, an effect of suppressing the contraction of the exterior body 40 is obtained. The fixing jig 800 sandwiches the first sealing portion 70 between a pair of walls 810, 820, and is therefore particularly effective in preventing the first sealing portion 70 (particularly the portion including the base 70X) from peeling off.

[0116] <2-3> In the above embodiment, the fixing jig 200 can omit at least one of the coupling portion 220 and the connection portion 230. In other words, it is sufficient that the fixing jig 200 has at least the first fixing portion 210. When the fixing jig 200 is configured only by the first fixing portion 210, the first fixing portion 210 is joined to the second surface 50YB of the protruding portion 50Y and at least a part of the second surface 42A of the exterior body 40 by an adhesive, heat sealing, or the like.

[0117] <2-4> In the above embodiment, the configuration of the first sealing portion 70 can be changed arbitrarily. For example, the thick portion 90 can be omitted from the first sealing portion 70. In the power storage device 10 of this modification, the thickness HA of the first sealing portion 70 may be constant or may vary partially. In addition, the first sealing portion 70 may be folded starting from the base 70X.

[0118] <2-5> In each of the above embodiments, the exterior film 50 of the electricity storage device 10 may protrude outward from at least one of the two lid bodies 60 in the FB direction. The electrode body 20 is sealed by closing the portion of the exterior film 50 that protrudes outward from the lid body 60. The portion of the exterior film 50 that protrudes outward from the lid body 60 may be folded inward so that the outer surfaces of the exterior film 50 come into contact with each other, as in a Goebel-top container, or may be folded toward any surface of the exterior body 40, as in a brick container.

[0119] <2-6> In each of the above embodiments, the exterior body 40 may not have one of the two lid bodies 60. In this modification, in the FB direction, in a portion of the exterior body 40 where the lid body 60 is omitted, the electrode body 20 is sealed by closing a portion of the exterior film 50 that protrudes outward beyond the electrode body 20. The portion of the exterior film 50 that protrudes outward beyond the electrode body 20 may be folded like a Goebel-top container or a brick container.

[0120] <2-7> In the above embodiment, it is possible to arbitrarily change the outer shape of the exterior body 40. The outer shape of the exterior body 40 may be a cylinder, a prism, or a cube.

[0121] <2-8> In the above embodiment, the electrode body 20 is wrapped in one exterior film 50, but it may be wrapped in two or more exterior films 50. [Explanation of symbols]

[0122] 10: Energy storage device 10Z: Intermediate 20: Electrode body 40: Exterior body 50: Exterior film 50Y: Overhang 60: Lid 70: First sealing part 70X: Root 100: Fixture 100X: Fixture 100Y: Fixture 100Z: Fixture 200: Fixture 500: Fixture 600: Fixture 700: Fixture 800: Fixture

Claims

[Claim 1] An electrode body; and an exterior body that seals the electrode body, The exterior body is An exterior film that wraps the electrode body; a main body in which at least the electrode body is wrapped with the exterior film; a protruding portion in which the exterior film protrudes outward beyond the main body portion; a first sealing portion in which the surfaces of the exterior film of the protruding portion facing each other are sealed; and a fixing jig that prevents the protruding portion from moving relative to the main body portion. Energy storage device.

Images