Method for producing power storage device, and power storage device

Abstract

To provide: a method for producing a power storage device that enables favorable production of a power storage device comprising a cover member; and the power storage device.SOLUTION: Disclosed is a method for producing a power storage device that comprises an electrode body and an outer package in which the electrode body is sealed. The outer package comprises: an outer package film which encloses the electrode body such that an opening is formed; a cover member disposed at the position of the opening; and a sealing part at which the cover member and the outer package film are joined to each other. The method for producing the power storage device comprises a sealing step in which the sealing part is formed using a sealing device. The sealing step comprises a first sealing step in which the sealing part is formed while one of the sealing device and the cover member is moved relative to the other.SELECTED DRAWING: Figure 16

Description

[Technical field]

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

[0002] Patent Document 1 discloses an example of an electricity storage device. This electricity storage device includes an electrode body and an exterior body that seals the electrode body. The exterior body includes an exterior film that wraps the electrode body so that an opening is formed, and a lid body that is placed on the opening. The exterior film and the lid body are joined together. [Prior art documents] [Patent documents]

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

[0004] The above electricity storage device has room for improvement in various respects, for example, the sealing performance between the corners of the lid and the exterior film is low.

[0005] An object of the present invention is to provide an electricity storage device manufacturing method capable of suitably manufacturing an electricity storage device including a lid body, and to provide an electricity storage device. [Means for solving the problem]

[0006] A manufacturing method for an electricity storage device according to a first 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 including an exterior film that wraps the electrode body so as to form an opening, a lid body that is placed in the opening, and a sealing portion in which the lid body and the exterior film are joined. The manufacturing method for the electricity storage device includes a sealing step of forming the sealing portion using a sealing device, the sealing step including a first sealing step of forming the sealing portion while moving one of the sealing device and the lid body relative to the other.

[0007] A manufacturing method for an electricity storage device according to a second aspect of the present invention is a manufacturing method for an electricity storage device according to the first aspect, further including a resealing step, which is carried out after the first sealing step, and which reseals the lid body and the exterior film.

[0008] A manufacturing method for an electricity storage device according to a third 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 including an exterior film that wraps the electrode body so as to form an opening, a lid that closes the opening, and a sealing portion in which the lid body and the exterior film are joined, the lid body having a plurality of sealing surfaces that are joined to the exterior film. The manufacturing method for the electricity storage device includes a sealing step of forming the sealing portion, in which adjacent sealing surfaces of the plurality of sealing surfaces are joined in sequence.

[0009] A manufacturing method for an electricity storage device according to a fourth 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 including an exterior film that wraps the electrode body so as to form an opening, a lid that closes the opening, and a sealing portion in which the lid body and the exterior film are joined. The manufacturing method for the electricity storage device includes a sealing step of forming the sealing portion, and the lid body is heated in a step performed prior to the sealing step.

[0010] A manufacturing method for an electricity storage device according to a fifth aspect of the present invention is a manufacturing method for an electricity storage device comprising an electrode body and an exterior body that seals the electrode body, wherein the exterior body includes an exterior film that wraps the electrode body so as to form an opening, a lid body that closes the opening, and a sealing portion in which the lid body and the exterior film are joined, and the manufacturing method for the electricity storage device includes a sealing step of forming the sealing portion using a sealing device, and in the sealing step, the amount of pressure of the sealing device against the exterior film and the lid body is controlled.

[0011] A manufacturing method for an electricity storage device according to a sixth aspect of the present invention is a manufacturing method for an electricity storage device including an electrode body, an electrode terminal electrically connected to the electrode body, and an exterior body sealing the electrode body, wherein the exterior body includes an exterior film that wraps the electrode body so as to form an opening, and a lid body that closes the opening. The manufacturing method for the electricity storage device includes a connecting step of connecting the electrode body and the electrode terminal, and an arrangement step of arranging the lid body on the side of the electrode body to which the electrode terminal is connected, and in the arrangement step, the positioning device positions the lid body relative to at least one of the electrode terminal and the electrode body.

[0012] A manufacturing method for an electricity storage device according to a seventh aspect of the present invention is a manufacturing method for an electricity storage device according to the sixth aspect, and includes a winding step of winding the exterior film around the electrode body and the cover body, and in the winding step, the positioning device positions the exterior film relative to at least one of the electrode terminal and the electrode body.

[0013] A manufacturing method for an electricity storage device according to an eighth aspect of the present invention is a manufacturing method for an electricity storage device including an electrode body, an electrode terminal electrically connected to the electrode body, and an exterior body sealing the electrode body, wherein the exterior body includes an exterior film that wraps the electrode body so as to form an opening, and a lid that closes the opening. The manufacturing method for the electricity storage device includes a connecting step of connecting the electrode terminal joined to the lid body and the electrode body, and in the connecting step, the lid body or the electrode terminal is positioned relative to the electrode body by a positioning device.

[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 according to the eighth aspect, and includes a winding step of wrapping the exterior film around the electrode body and the cover body, and in the winding step, the positioning device positions the exterior film relative to the electrode body.

[0015] A manufacturing method for an electricity storage device according to a tenth aspect of the present invention is a manufacturing method for an electricity storage device including an electrode body and an exterior body sealing the electrode body, wherein the exterior body includes an exterior film that wraps the electrode body so as to form an opening, and a lid body that closes the opening. The manufacturing method for the electricity storage device includes a winding step of winding the exterior film around the electrode body and the lid body, in which the exterior film is wound around the electrode body and the lid body while at least one of the electrode body and the lid body placed on the exterior film is pressed against the exterior film.

[0016] An eleventh aspect of the present invention relates to a method for manufacturing an electricity storage device according to the tenth aspect, wherein in the wrapping step, a portion of the exterior film that corresponds to a corner of the lid body is pressed against the lid body.

[0017] A manufacturing method for an electricity storage device according to a twelfth aspect of the present invention is a manufacturing method for an electricity storage device comprising an electrode body and an outer casing that seals the electrode body, wherein the outer casing includes an outer casing film that wraps the electrode body so as to form an opening, a lid that closes the opening, and a sealing portion in which the lid body and the outer casing film are joined, and the manufacturing method for the electricity storage device includes a sealing step of forming the sealing portion using a sealing device, in which the sealing step forms the sealing portion in a state in which at least one of the lid body and the electrode body wrapped in the outer casing film is placed on an elastic body.

[0018] A method for manufacturing an electricity storage device according to a thirteenth aspect of the present invention is a method for manufacturing an electricity storage device including an electrode body and an exterior body that seals the electrode body, the exterior body including an exterior film that wraps the electrode body so as to form an opening, a lid that closes the opening, and a sealing portion in which the lid and the exterior film are joined. The method for manufacturing an electricity storage device includes a sealing step of forming the sealing portion using a sealing device, in which the sealing step forms the sealing portion with a heat-resistant elastic body sandwiched between the exterior film and the sealing device.

[0019] A manufacturing method for an electricity storage device according to a fourteenth aspect of the present invention is a manufacturing method for an electricity storage device including an electrode body and an exterior body sealing the electrode body, the exterior body including an exterior film wrapping the electrode body so as to form an opening, and a lid body closing the opening. The manufacturing method for the electricity storage device includes a winding step of winding the exterior film around the electrode body, in which the exterior film is wound around the electrode body so as to form a protruding portion of the exterior film that protrudes outward beyond the electrode body, and the protruding portion is pulled in an arbitrary direction with a predetermined strength, the predetermined strength being a strength that is included in a range in which the stress and strain acting on the exterior film suppress the occurrence of wrinkles and sagging in the exterior film.

[0020] A manufacturing method for an electricity storage device according to a fifteenth aspect of the present invention is a manufacturing method for an electricity storage device comprising an electrode body and an outer casing that seals the electrode body, wherein the outer casing includes an outer casing film that wraps the electrode body so as to form an opening, and a lid that closes the opening, and the manufacturing method for the electricity storage device includes a winding step of winding the outer casing film around the electrode body and the lid body, in which the outer casing film is wound around the electrode body and the lid body so as to form an excess portion of the outer casing film that protrudes outside the lid body, and the excess portion is cut or folded in a step performed after the winding step.

[0021] An electricity storage device according to a sixteenth aspect of the present invention comprises an electrode body, a strip-shaped member wrapped around the electrode body, and an exterior body that seals the electrode body and the strip-shaped member, the exterior body comprising an exterior film that wraps the electrode body and the strip-shaped member so as to form an opening, and a lid that closes the opening, and the strip-shaped member and the exterior film are joined together.

[0022] An electricity accumulation device according to a seventeenth aspect of the present invention is the electricity accumulation device according to the sixteenth aspect, wherein the belt-shaped member and the electrode body are joined together. Effect of the Invention

[0023] According to the electricity storage device manufacturing method and electricity storage device of the present invention, an electricity storage device including a lid can be suitably manufactured. [Brief description of the drawings]

[0024] [Figure 1A] FIG. 1 is a plan view illustrating an electricity storage device according to an embodiment. [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 an example of a layer structure of an exterior film included in the electricity storage device of FIG. 1A. [Diagram 3] 1B is a perspective 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] FIG. 4 is a cross-sectional view of the lid of FIG. [Figure 6] FIG. 1A is a perspective view of an intermediate body placed on a fixing jig used in a manufacturing process of an electricity storage device. [Figure 7] 1B is a flowchart showing an example of a manufacturing process for the electricity storage device in FIG. 1A. [Figure 8] FIG. 8 is a diagram relating to the second step of FIG. 7. [Figure 9] FIG. 8 is a diagram relating to the third step in FIG. 7. [Figure 10] FIG. 8 is another view of the third step of FIG. 7 . [Figure 11] 8 is yet another diagram relating to the third step of FIG. 7. [Figure 12] 8 is a diagram showing an example of the relationship between strain and stress acting on an exterior film in the third step of FIG. 7. [Figure 13] FIG. 8 is a diagram relating to the fourth step in FIG. 7. [Figure 14] FIG. 8 is a diagram relating to the fifth step in FIG. 7. [Figure 15] 8 is a flowchart showing an example of a fifth step in FIG. 7. [Figure 16] FIG. 8 is another view relating to the fifth step of FIG. 7 . [Figure 17] FIG. 8 is a diagram relating to the sixth step in FIG. 7. [Figure 18] FIG. 8 is a diagram relating to the eighth and ninth steps of FIG. 7. [Figure 19] 1B is a side view of the electricity storage device in FIG. 1A with a transportation jig attached thereto. FIG. [Figure 20] Plan view of Figure 19. [Figure 21] FIG. 13 is a perspective view of a lid provided in an electricity storage device according to a modified example. [Figure 22] FIG. 13 is a perspective view of a lid provided in an electricity storage device according to another modified example. [Figure 23] FIG. 13 is a side view of an electricity storage device according to still another modified example. [Figure 24] FIG. 23 is a perspective view of a fixing jig for fixing the lid body of FIG. 22. [Diagram 25] FIG. 13 is a plan view of an electricity storage device according to a modified example. [Figure 26] 8 is a diagram showing a modified process of the third process in FIG. 7. [Figure 27] FIG. 8 is a diagram showing a modified process of the fifth process in FIG. 7. [Figure 28] FIG. 8 is a diagram relating to a process of another modified example of the fifth process of FIG. 7, showing a state in which the seal bar is in the initial position. [Figure 29] FIG. 29 shows the state in which the seal bar in FIG. 28 is in the reference position. [Diagram 30] FIG. 8 is a diagram showing a process of yet another modified example of the fifth process of FIG. 7. [Diagram 31] 1B is a flowchart showing a modified example of the manufacturing process for the electricity storage device in FIG. 1A. [Diagram 32] A figure relating to the 32nd step of Figure 31. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] 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.

[0026] [1. Embodiment] <1-1. Configuration of the power storage device> FIG. 1A is a plan view that shows a schematic diagram of an electricity storage device 10 according to a first embodiment. FIG. 1B is a diagram that shows a method for measuring the seal strength of the second sealing portion 80 of the electricity storage device 10. FIG. 2 is a cross-sectional view that shows a layer structure of an exterior film 50 that the electricity storage device 10 of FIG. 1A has. FIG. 3 is a perspective view of a lid body 60 that the electricity storage device 10 of FIG. 1 has. FIG. 4 is a diagram showing a state in which the exterior film 50 that the electricity storage device 10 of FIG. 1A has been unfolded. FIG. 5 is a cross-sectional view of the lid body 60 of FIG. 3. FIG. 6 is a perspective view of a state in which an intermediate body is placed on a fixing jig 100 that is used in a manufacturing process of the electricity storage device 10. In FIG. 1A, the direction of the arrow UD indicates the thickness direction of the electricity storage device 10, the direction of the arrow LR indicates the width direction of the electricity storage device 10, and the direction of the arrow FB indicates the depth direction of the electricity storage device 10. The directions shown by the arrows UDLRFB are common to the following figures.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] The exterior body 40 seals the electrode body 20. The exterior body 40 includes an exterior film 50 and a lid body 60. The exterior film 50 wraps the electrode body 20 so as to have an opening 40A. In this embodiment, the exterior film 50 is wrapped around the electrode body 20 so as to have an opening 40A. The lid body 60 is disposed in the opening 40A. Note that the electrode body 20 may be housed inside the exterior film 50 that is configured in a cylindrical shape so as to form the opening 40A, and the opening 40A may be closed by the lid body 60.

[0031] From the viewpoint of suitable adhesion to the lid 60, it is preferable that an adhesive film (not shown) is bonded to the electrode terminal 30. The adhesive film can be selected arbitrarily as long as it can bond the electrode terminal 30 made of metal and the lid 60 made of resin. For example, the adhesive film can be a polyolefin resin such as a polyethylene resin or a polypropylene resin, a cyclic polyolefin resin, or an acid-modified polyolefin resin obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. The adhesive film can be a single layer or two or more layers of these films. In this embodiment, the adhesive film is bonded to almost the entire part of the electrode terminal 30 covered by the lid 60.

[0032] 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) by cold forming (for example, a forming depth of 15 mm), pinholes or cracks will occur in the exterior film 50, which is likely to cause a decrease in battery performance. On the other hand, 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. In addition, in order to reduce the dead space between the electrode body 20 and the exterior film 50 to improve the volumetric energy density of the power storage device 10, it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20. In addition, in an all-solid-state battery, it is necessary to apply a high pressure uniformly from the outer surface of the battery to exhibit battery performance, so it is necessary to eliminate the space between the electrode body 20 and the exterior film 50, and therefore it is preferable that the exterior film 50 is wrapped so as to contact the outer surface of the electrode body 20.

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

[0034] 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.

[0035] 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.

[0036] 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.

[0037] From the viewpoint of improving the formability or conformability of the exterior film 50, the aluminum alloy foil is preferably a soft aluminum alloy foil made of, for example, an annealed aluminum alloy, 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.

[0038] 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.

[0039] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, and SUS316L, and among these, SUS304 is particularly preferred.

[0040] In the case of a metal foil, the thickness of the barrier layer 52 is sufficient to at least function as a barrier layer that prevents moisture from penetrating, and may be, for example, about 9 to 200 μm. The thickness of the barrier layer 52 is preferably about 85 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, and particularly preferably about 35 μm or less. The thickness of the barrier layer 52 is preferably about 10 μm or more, even more preferably about 20 μm or more, and more preferably about 25 μm or more. The preferred ranges of the thickness of the barrier layer 52 include about 10 to 85 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 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 range is 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. The 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. The exterior film 50 has high formability, which facilitates deep drawing and can contribute to increasing the capacity of the electricity storage device. In addition, since the rigidity of the exterior film 50 is increased, when the exterior film 50 is wrapped around the electrode body 20, the exterior film 50 can be suitably wrapped around the electrode body 20. Furthermore, when the capacity of the electricity storage device is increased, the weight of the electricity storage device increases, but increasing the rigidity of the exterior film 50 can contribute to high sealing performance of the electricity storage device.In particular, when the barrier layer 52 is made of stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, even more preferably about 40 μm or less, even more preferably about 30 μm or less, and particularly preferably about 25 μm or less. The thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Preferred ranges for the thickness of the stainless steel foil include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0041] 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.

[0042] The corrosion-resistant coating prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base layer 51 when the exterior film 50 is formed or wound, 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 forming.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

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

[0048] The lid 60 shown in Fig. 3 has, for example, a rectangular parallelepiped shape and is, for example, a resin molded product made of a resin material. The lid 60 may be a metal molded product. The material constituting the lid 60 may include at least two or more types of materials among a metal oxide, a carbon material, and a rubber material, and may include a metal oxide, a carbon material, and a rubber material.

[0049] The lid body 60 is preferably made of a resin material. Here, "made 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] The lid body 60 may be configured to include a conductive material. "Configured to include a conductive material" means that, when the entire material constituting the lid body 60 is taken as 100% by mass, the content of the conductive material is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more. In other words, the material constituting the lid body 60 can contain, in addition to the conductive material, a material other than the conductive material.

[0056] The conductive material constituting the lid body 60 is, for example, a metal material. The metal material constituting the lid body 60 is, for example, aluminum, an aluminum alloy, nickel, copper, or a copper alloy. For example, when the electrode body 20 is a lithium ion battery, the lid body 60 connected to the positive electrode is preferably made of aluminum or an aluminum alloy. The lid body 60 connected to the negative electrode is preferably made of 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 composed of a conductive material, the lid body 60 also functions as the electrode terminal 30. Since the electrode terminal 30 can be omitted from the electricity storage device 10, the configuration of the electricity storage device 10 can be simplified.

[0057] When the lid 60 is composed of a conductive material, the lid 60 may be bonded to the exterior film 50 via an adhesive film. The adhesive film can be selected arbitrarily as long as it can bond the exterior film 50 and the lid 60. The adhesive film is preferably a laminated film having at least a heat-sealable resin layer, a heat-resistant base material layer, and a heat-sealable resin layer in this order. The specifications of the heat-sealable resin layer of the adhesive film can be the same as those of the heat-sealable resin layer 53. The materials constituting the heat-sealable resin layers on both sides of the adhesive film may be the same or different materials, and are appropriately selected according to the materials constituting the heat-sealable resin layer 53 of the exterior film 50 and the materials constituting the lid 60. The material constituting the heat-sealable resin layer on the side of the adhesive film that is bonded to the lid 60 is preferably an acid-modified polyolefin resin graft-modified with an acid such as maleic anhydride. The heat-sealable resin layer of the adhesive film on the side to be bonded to the exterior film 50 is preferably made of the same material as that constituting the heat-sealable resin layer 53 of the exterior film 50 .

[0058] The heat-resistant base layer may be any film made of a heat-resistant resin, such as a non-stretched or stretched film of polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide, polymethylpentene (registered trademark), polyacetal cyclic polyolefin, polyethylene, polypropylene, etc. Polyethylene terephthalate is particularly preferred because it is inexpensive and has high strength.

[0059] The adhesive film preferably has adhesiveness. When the adhesive film is disposed between the exterior film 50 and the lid 60 and a second sealing portion 80 is formed as described below, the adhesive film is unlikely to be displaced relative to the lid 60 and the exterior film 50. By incorporating a tackifier resin into the heat-sealable resin layer of the adhesive film, the adhesive film can be given adhesiveness. Examples of the tackifier resin include amorphous polyolefins. Examples of the amorphous polyolefins include amorphous polypropylene and copolymers of amorphous propylene and other α-olefins. The content of the tackifier resin in the base material constituting the heat-sealable resin is preferably 10 to 20% by weight or less.

[0060] The cover 60 has a main body 60A. The main body 60A has a first surface 61, a second surface 62, and a sealing surface 63. The first surface 61 faces the electrode body 20. The second surface 62 is the surface opposite to the first surface 61. The sealing surface 63 is connected to the first surface 61 and the second surface 62, and is joined to the heat-sealable resin layer 53 of the exterior film 50.

[0061] The seal surface 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.

[0062] When the main body 60A is plate-shaped, it is preferable that the main body 60A 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 main body 60A is plate-shaped, it is preferable that the sealing surface 63 of the main body 60A has a certain degree of thickness so that the sealing surface 63 of the main body 60A and the exterior film 50 can be suitably heat-sealed when forming the second sealing portion 80 described later. The minimum value of the thickness of the main body 60A is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum value of the thickness of the main body 60A is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum value of the thickness of the main body 60A may be 20 mm or more. The preferred ranges of the thickness of the material constituting the main body 60A are 1.0 mm to 20 mm, 1.0 mm to 15 mm, 1.0 mm to 10 mm, 3.0 mm to 20 mm, 3.0 mm to 15 mm, 3.0 mm to 10 mm, 4.0 mm to 20 mm, 4.0 mm to 15 mm, and 4.0 mm to 10 mm. In this embodiment, when the main body 60A is expressed as a plate, the material constituting the main body 60A does not include films defined by the [Packaging Terminology] standard of the JIS (Japan Industrial Standards). The thickness of the main body 60A may vary depending on the part of the main body 60A. When the thickness of the main body 60A varies depending on the part, the thickness of the main body 60A is the thickness of the thickest part.

[0063] The main body 60A 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.

[0064] Examples of materials constituting the main body 60A include polyester-based resins such as polyethylene terephthalate resins and polybutylene terephthalate resins, polyolefin-based resins such as polyethylene resins, fluorine-based resins, and polypropylene resins, cyclic polyolefin-based resins, and acid-modified polyolefin-based resins obtained by graft-modifying these polyolefin-based resins with an acid such as maleic anhydride. From the viewpoint of suitable heat-sealing the main body 60A and the exterior film 50, it is preferable that the main material of the material constituting the main body 60A and the material constituting the heat-sealable resin layer 53 of the exterior film 50 are the same. In this embodiment, the main material of the main body 60A and the material constituting the heat-sealable resin layer 53 are, for example, polyolefin-based resins such as polyethylene resins and polypropylene resins, or acid-modified polyolefin-based resins obtained by graft-modifying these polyolefin-based resins with an acid such as maleic anhydride. The main material refers to, for example, a material that occupies 50% or more of the materials contained in the components.

[0065] In this embodiment, the main body 60A 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. In a state in which the electrode body 20 is wrapped in the exterior film 50, the electrode terminal 30 protrudes to the outside of the exterior body 40 through the through hole 60X formed in the main body 60A. A small gap between the through hole 60X of the main body 60A and the electrode terminal 30 is filled with, for example, resin. Note that, in the power 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 on 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 or film. In another example, the electrode terminal 30 may protrude to the outside of the exterior body 40 from between the seal surface 63 of the main body 60A and the exterior film 50. In this case, the through hole 60X may not be formed in the cover 60. In the electricity storage device 10, the main body 60A and the electrode terminal 30 are provided as separate bodies, but the main body 60A and the electrode terminal 30 may be formed integrally. Note that, even when the electrode terminal 30 does not protrude from the edge of the exterior body 40, the main body 60A may not be formed with the through hole 60X.

[0066] In the manufacturing process of the electricity storage device 10, an intermediate body is manufactured in which the lid body 60 is disposed on both ends of the electrode body 20. The intermediate body is moved to a work site for the next process. In this embodiment, a fixing jig 100 for fixing the position of the lid body 60 relative to the electrode body 20 is attached to the intermediate body while the intermediate body is being moved. Therefore, the lid body 60 has, in addition to a main body 60A, a protrusion 60B to which the fixing jig 100 is attached.

[0067] The protrusion 60B protrudes from the second surface 62 of the main body 60A. The number of protrusions 60B provided on the lid 60 can be selected arbitrarily. In this embodiment, the lid 60 has two protrusions 60B. The lid 60 may have one, or three or more protrusions 60B. The position on the second surface 62 from which the protrusion 60B protrudes can be selected arbitrarily. When the through hole 60X is formed in the main body 60A as in this embodiment, it is preferable that the protrusion 60B is formed at a position away from the through hole 60X so that the electrode terminal 30 and the protrusion 60B do not interfere with each other.

[0068] The specific configuration of the protruding portion 60B can be selected arbitrarily as long as the fixing jig 100 can be fixed. In this embodiment, the protruding portion 60B is a fixing part embedded in the main body 60A. The fixing part is, for example, an insert nut. The insert nut is formed with a female screw or a male screw. As shown in FIG. 5, the end of the protruding portion 60B opposite to the end protruding from the second surface 62 is embedded inside the main body 60A. That is, the protruding portion 60B does not penetrate the main body 60A. When the insert nut is made of a metal material, it is preferable that the insert nut is subjected to a corrosion-resistant treatment such as a chromate treatment in order to increase the joining strength with the lid body 60. It is preferable that the load capacity of one insert nut is equal to or greater than the value obtained by dividing the weight of the electricity storage device 10 by the total number of the protruding portions 60B. The fixing part may have at least one of a suction cup, a magnet, a convex portion, a Velcro tape (registered trademark), a spring pin, and a clamp so that the fixing jig 100 can be fixed.

[0069] 6, the fixing jig 100 includes a lid fixing part 110 to which the lid body 60 is fixed, and a mounting part 120 on which the electrode body 20 is placed. The lid fixing part 110 and the mounting part 120 are connected by any means. The lid fixing part 110 and the mounting part 120 may be formed integrally.

[0070] The lid fixing part 110 has a support part 111 on which the lid body 60 is placed, and a wall part 112 rising from the support part 111. The wall part 112 is formed with holes 112X according to the number of the protrusions 60B. The lid body 60 is fixed to the lid fixing part 110 by meshing a screw formed in the insert nut constituting the protrusion 60B with a male screw or a female screw. If the screw formed in the insert nut constituting the protrusion 60B is a female screw, the female screw meshes with a male screw inserted into the hole 112X. If the screw formed in the insert nut constituting the protrusion 60B is a male screw, the male screw meshes with a female screw formed in a nut, a socket, or the like. The female screw may be entirely disposed outside the hole 112X, or at least a part of the female screw may be inserted into the hole 112X. The wall part 112 is further formed with a slit 112Y into which the electrode terminal 30 is inserted. The slit 112Y penetrates the wall part 112. The wall portion 112 may include a plurality of divided parts, and may be configured so as to sandwich the electrode terminal 30 between the plurality of parts. When the lid body 60 also functions as an electrode terminal, the slit 112Y may be omitted. The mounting portion 120 is, for example, plate-shaped, and substantially the entire electrode body 20 is placed thereon. The fixing jig 100 may be attached to the completed electricity storage device 10. That is, the fixing jig 100 may also be used when the electricity storage device 10 is in use.

[0071] In this embodiment, with the exterior film 50 wrapped around the electrode body 20 so as to have an opening 40A, the facing surfaces of the exterior film 50 (heat-fusible resin layer 53) are heat-sealed to form the first sealing portion 70.

[0072] The first sealed portion 70 is formed by heat-sealing a portion including the first edge 50A and a portion including the second edge 50B of the exterior film 50 shown in FIG. 4. The first sealed portion 70 extends in the longitudinal direction (FB direction) of the exterior body 40. The position at which the first sealed portion 70 is formed in the exterior body 40 can be selected arbitrarily. In this embodiment, the root 70X of the first sealed portion 70 is preferably located on the side 43 at the boundary between the first surface 41 and the second surface 42 of the exterior body 40. The first surface 41 has a larger area than the second surface 42. The root 70X of the first sealed portion 70 may be located on any surface of the exterior body 40. In this embodiment, the first sealed portion 70 protrudes outward from the electrode body 20 in a plan view. The first sealed portion 70 may be folded, for example, toward the second surface 42 of the exterior body 40, or toward the first surface 41.

[0073] 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 seal surface 63 of the lid body 60. Hereinafter, the seal strength between the heat-sealable resin layer 53 of the exterior film 50 and the seal surface 63 of the lid body 60 may be referred to as the seal strength of the second sealed portion 80. The seal strength of the second sealed portion 80 is the seal strength between the heat-sealable resin layer 53 and the lid body 60 at the long side portion of the seal surface 63, i.e., the seal surface 63 extending in the LR (width) direction in FIG. 1A.

[0074] 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. Note that the seal strength of the second sealing portion 80 in the case where the lid body 60 is divided into multiple parts including long sides and short sides is the seal strength of the long side portion of the seal surface 63 of the multiple parts.

[0075] 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.

[0076] <1-2. Method for manufacturing electricity storage device> 7 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, and a ninth step. The first step to the ninth step are performed, for example, by a manufacturing apparatus for the power storage device 10. Note that the following first step to ninth step are merely names of the steps in the method for manufacturing the power storage device 10 specified for convenience, and do not necessarily refer to the order of the steps.

[0077] In the first process of step S11 (lid unit manufacturing process), the manufacturing device manufactures a pair of lid units 60Z in which the lid body 60 and the electrode terminals 30 are joined together.

[0078] The second step (connecting step) of step S12 is performed after the first step. In the second step, the manufacturing equipment places a pair of lid units 60Z on both ends of the electrode body 20 and electrically connects the electrode terminals 30 and the electrode body 20.

[0079] FIG. 8 is a diagram relating to the second step. In the second step, the manufacturing device positions the pair of lid units 60Z relative to the electrode body 20 by a positioning device (not shown). In the second step, the pair of lid units 60Z is positioned relative to the electrode body 20, for example, based on the long side PA and short side PB of the electrode body 20 in a plan view. As the positioning device, for example, a known image processing device can be used. In this embodiment, an image processing device manufactured by Keyence Corporation is used as the image processing device. The detection method of the image processing device is edge position measurement using a transmission inspection. The resolution of the image processing device is 0.01 mm. In this embodiment, the image processing device is used to detect the short side PB by a transmission inspection, and the amount of correction with respect to the reference side on the opposite side is calculated from the position information. After the second step is completed, a fixing jig 100 (see FIG. 6) is attached to the intermediate body including the electrode body 20 and the pair of lid units 60Z. The intermediate body is transported to a work site for the third step with the fixing jig 100 attached.

[0080] The third step (winding step) of step S13 is performed after the second step. In the third step, the fixing jig 100 is removed from the intermediate body. In the third step, the manufacturing equipment winds the exterior film 50 around the electrode body 20 and the lid body 60. In the third step, the exterior film 50 is positioned relative to the intermediate body based on the long side PA and the short side PB set in the second step. Also, in the third step, an exterior film 50 having a larger area than the exterior film 50 of the completed electricity storage device 10 is used to form the protruding portion 90 (see FIG. 16).

[0081] 9 to 11 are diagrams relating to the third step. In the third step, the manufacturing device places the electrode body 20 on the exterior film 50. By placing the electrode body 20 on the exterior film 50, one of the pair of first surfaces 41 of the exterior body 40 is formed. The manufacturing device presses at least one of the electrode body 20 and the lid body 60 placed on the exterior film 50 against the exterior film 50, and wraps the exterior film 50 around the electrode body 20 and the lid body 60. In this embodiment, the electrode body 20 and the lid body 60 are pressed against the exterior film 50 by, for example, a bar-shaped pressing member 130. Since the third step can be performed with the electrode body 20 and the lid body 60 placed on a table on which the exterior film 50 is placed, the exterior film 50 can be easily wrapped around the electrode body 20 and the lid body 60. It is preferable that the bar-shaped pressing member 130 contacts substantially the entire upper surface of the electrode body 20 and the lid body 60.

[0082] 10 , in the third step, the exterior film 50 is folded so as to form one of the pair of second surfaces 42 of the exterior body 40. After the exterior film 50 is folded, a portion of the exterior film 50 corresponding to a corner of the lid body 60 is pressed against the lid body 60 by, for example, a bar-shaped pressing member 140. Note that the pressing member 140 may be shaped to press the entire second surface 42 against the electrode body 20 and the lid body 60, or may be, for example, L-shaped corresponding to the corner between the first surface 41 and the second surface 42.

[0083] 11 , in a third step, the exterior film 50 is folded to form the other second surface 42 of the pair of second surfaces 42 of the exterior body 40. After the exterior film 50 is folded, a portion of the exterior film 50 that corresponds to the corner of the lid body 60 is pressed against the lid body 60 by, for example, a bar-shaped pressing member 150.

[0084] Next, after the pressing member 130 (see FIG. 9) is separated from the electrode body 20, the exterior film 50 is folded so that the other of the pair of first surfaces 41 of the exterior body 40 is formed.

[0085] In addition, in the winding process, from the viewpoint of preventing the occurrence of wrinkles and sagging in the exterior film 50, it is preferable that the manufacturing equipment pulls the portion of the exterior film 50 corresponding to the protrusion portion 90 (see Figure 16) in any direction with a predetermined strength.

[0086] 12 is an example of a graph showing the relationship between the strain and stress acting on the exterior film 50. If the strain and stress acting on the exterior film 50 are too small, sagging occurs in the exterior film 50 wrapped around the electrode body 20. In this embodiment, in order to prevent sagging from occurring in the exterior film 50, a predetermined strength is determined so that the strain acting on the exterior film 50 is equal to or greater than a lower limit XA (%) and the stress acting on the exterior film 50 is equal to or greater than a lower limit YA (MPa).

[0087] On the other hand, if the strain and stress acting on the exterior film 50 are too large, wrinkles will occur in the exterior film 50 wrapped around the electrode body 20. In this embodiment, in order to prevent wrinkles from occurring in the exterior film 50, a predetermined strength is determined so that the strain acting on the exterior film 50 is equal to or less than an upper limit value XB (%) and the stress acting on the exterior film 50 is equal to or less than an upper limit value YB (MPa).

[0088] That is, in this embodiment, in the winding process, the portion of the exterior film 50 corresponding to the protruding portion 90 is pulled with a predetermined strength, so that the strain acting on the exterior film 50 is within the range of not less than the lower limit XA (%) and not more than the upper limit XB (%), and the stress acting on the exterior film 50 is within the range of not less than the lower limit YA (MPa) and not more than the upper limit YB (MPa). An example of the lower limit XA is 0.10 (%). An example of the upper limit XB is 0.43 (%). An example of the lower limit YA is 1.1 (MPa). An example of the upper limit YB is 13.2 (MPa).

[0089] The fourth step of step S14 is performed after the third step. As shown in Fig. 13, in the fourth step, the manufacturing device forms a first FB direction sealed portion 71 having an unsealed portion 71Z in the center of a portion of the exterior film 50 where the protruding portion 90 is formed. The first FB direction sealed portion 71 extends in the FB direction. The hatched portion in Fig. 13 shows an example of an area where the first FB direction sealed portion 71 is formed.

[0090] The fifth step (sealing step) of step S15 is performed before or after the fourth step. The fifth step may be performed in parallel with the third step. As shown in FIG. 14, in the fourth step, the manufacturing device forms the second sealing portion 80. In the fifth step, it is preferable that the second sealing portion 80 is formed in a state in which the fixing jig 100 is attached to the lid body 60. The hatched portion shown in FIG. 14 indicates an example of the region where the second sealing portion 80 is formed.

[0091] As shown in FIG. 15, the fifth step preferably includes a first sealing step of step S21 and a resealing step of step S22 that is carried out after the first sealing step.

[0092] In the first sealing step, from the viewpoint of suitably joining the boundaries 64-67 of the lid body 60 and the exterior film 50, in particular, the manufacturing apparatus preferably forms the second sealed portion 80 while moving one of the sealing device 160 (see FIG. 16) and the lid body 60 relative to the other. In this embodiment, the second sealed portion 80 is formed while the sealing device 160 moves relative to the lid body 60. In this embodiment, for example, an ultrasonic sealing device or a welding machine is used as the sealing device 160. For example, the sealing device 160 may be a heat sealing device using a roller, or may be a heat sealing device using a seal bar shorter than any of the sealing surfaces 63A-63D of the lid body 60.

[0093] FIG. 16 is a diagram relating to the first sealing step. In the first sealing step, the sealing device 160 preferably joins the sealing surfaces adjacent to the exterior film 50 in sequence. The sealing device 160 moves, for example, to pass through the first sealing surface 63A, the third sealing surface 63C, the fourth sealing surface 63D, and the second sealing surface 63B in this order. The sealing device 160 may move through the second sealing surface 63B, the fourth sealing surface 63D, the third sealing surface 63C, and the first sealing surface 63A in this order. In the first sealing step, for example, the second sealing portion 80 may be formed by two sealing devices 160. For example, one sealing device 160 may start moving from the boundary 67 and move to pass through the third sealing surface 63C and the first sealing surface 63A in this order. The other sealing device 160 may start moving from the boundary 67 and move to pass through the fourth sealing surface 63D and the second sealing surface 63B in this order. In the first sealing step, the sealing device 160 may start moving from an intermediate portion of the first sealing surface 63A, the second sealing surface 63B, the third sealing surface 63C, or the fourth sealing surface 63D.

[0094] The resealing step in step S22 is performed from the viewpoint of further increasing the seal strength of the second sealing portion 80. The method of the resealing step can be selected arbitrarily. The resealing step may be, for example, the same method as the first sealing step. In the resealing step, the first sealing surface 63A to the fourth sealing surface 63D may be heat-sealed in any order using a seal bar.

[0095] The sixth step of step S16 is performed before or after the fifth step. The sixth step may be performed in parallel with the fourth step. As shown in FIG. 17, in the sixth step, the manufacturing apparatus forms a first LR direction seal portion 72 extending in the LR direction. In the sixth step, the first LR direction seal portion 72 is formed so as to overlap partially with the first FB direction seal portion 71 in a portion including the root 70X. Completion of the sixth step completes a protruding portion 90 having a larger area in a plan view than the first sealing portion 70 of the completed electricity storage device 10. The hatched portion in FIG. 17 shows an example of an area where the first LR direction seal portion 72 is formed.

[0096] The seventh step of step S17 is performed after the sixth step. In the seventh step, the manufacturing device injects an electrolyte through the opening 90X of the protruding portion 90. After the seventh step, the edge including the opening 90X of the protruding portion 90 is heat sealed, and an aging step is performed. Gas generated in the aging step is discharged through the opening 90X.

[0097] The eighth step of step S18 is performed after the aging step is completed. As shown in Fig. 18, in the eighth step, the manufacturing equipment forms the first sealing portion 70. In the eighth step, the first FB direction seal portion 71 and the first LR direction seal portion 72 are also sealed again. Note that the hatched portion in Fig. 18 shows an example of the region where the first sealing portion 70 is formed.

[0098] The ninth step of step S19 is performed after the eighth step. In the ninth step, the manufacturing equipment cuts off the portion of the protruding portion 90 other than the first sealing portion 70. The dashed dotted line X shown in FIG. 18 is an example of a line indicating the position where the protruding portion 90 is cut off in the ninth step.

[0099] <1-3.Transportation fixture> In the above embodiment, a transportation jig 200 may be used to transport the electrode body 20, the intermediate body, or the completed electricity storage device 10 (hereinafter, these are referred to as "objects to be transported"). Fig. 19 is a side view of the electricity storage device 10 to which the transportation jig 200 is attached. Fig. 20 is a plan view of Fig. 19.

[0100] The transport jig 200 includes a pair of plates 211, 212, and a connecting portion 213 that connects the pair of plates 211, 212. The plate 211 covers one of the first surfaces 41 of the exterior body 40. The plate 212 covers the other of the first surfaces 41 of the exterior body 40. A handle 211A is attached to the plate 211. This allows an operator to easily hold the transport jig 200. The handle 211A may be omitted.

[0101] The area of ​​the pair of plates 211, 212 in a plan view is larger than the area of ​​the first surface 41 of the exterior body 40. For this reason, the pair of plates 211, 212 protrude from the first surface 41 in the L-R direction. Holes 211X, 212X into which the connecting portion 213 is inserted are formed in the portions of the pair of plates 211, 212 protruding from the first surface 41.

[0102] The specific configuration of the connecting part 213 can be arbitrarily selected as long as it is a configuration capable of connecting the pair of plates 211, 212. It is preferable that the connecting part 213 is detachable from the pair of plates 211, 212 so that the transportation jig 200 can be easily attached to and detached from the transport object. In this embodiment, the connecting part 213 is a bolt. The connecting part 213 is, for example, inserted into the holes 211X, 212X and fixed to the pair of plates 211, 212 by a nut.

[0103] The number of connecting parts 213 included in the transportation jig 200 can be selected arbitrarily. In this embodiment, the transportation jig 200 has six connecting parts 213. The transportation jig 200 may have one to five connecting parts 213, or seven or more connecting parts 213.

[0104] <1-4. Effects of the embodiment> According to the above embodiment, in the first sealing step, the manufacturing apparatus forms the second sealed portion 80 while moving the sealing device 160 relative to the lid body 60. This allows the lid body 60, particularly the boundaries 64 to 67, to be joined favorably to the exterior film 50. This allows the electricity storage device 10 to be manufactured favorably.

[0105] [2. Modifications] The above-described embodiments are examples of possible forms of the method for manufacturing an electricity storage device according to the present invention, and are not intended to limit the forms. The method for manufacturing an 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. The following modified forms can be combined with each other as long as there is no technical contradiction.

[0106] <2-1> In the above embodiment, the configuration of the lid 60 can be changed arbitrarily. FIG. 21 is a perspective view of a lid 260 of a modified example. The lid 260 may include a main body 60A and a thick portion 261 protruding from the second surface 62 of the main body 60A. The number of thick portions 261 included in the lid 260 can be selected arbitrarily. In the example shown in FIG. 21, the lid 260 includes four thick portions 261. The lid 260 may include one to three, or five or more thick portions 261. A hole 260X is formed in the thick portion 261 and the main body 60A. It is preferable that the hole 260X does not penetrate the thick portion 261 and the main body 60A. In this modified example, the protruding portion 60B is a screw inserted into the hole 260X. An arbitrary fixing member may be inserted into the hole 260X. A female screw may be formed on the inner peripheral surface of the hole 260X. 21, a thick portion may be formed at a position on the first surface 61 of the main body 60A that faces the thick portion 261 across the main body 60A. In this case, it is preferable that the hole 260X does not penetrate the thick portion 261, the main body 60A, and the thick portion formed on the first surface 61. Note that the thick portion 261 and the thick portion formed on the first surface 61 do not have to face each other across the main body 60A. In other words, the thick portion may be formed on at least one of the first surface 61 and the second surface 62.

[0107] Fig. 22 is a perspective view of a lid 360 of another modified example. The lid 360 may include a main body 60A and a protruding portion 360B protruding from the second surface 62 of the main body 60A. The protruding portion 360B may be formed integrally with the main body 60A. The protruding portion 360B has a shape corresponding to a pull pin provided to suppress warping of the lid 60 when the lid 360 is insert-molded, for example. Note that in Fig. 22, the number of protruding portions 360B may be one, two, or four or more.

[0108] FIG. 23 is a side view of an electricity storage device 10 including a lid body 460 of yet another modified example. The lid body 460 has a protruding portion 460B. The protruding portion 460B has a broken portion 460X. The broken portion 460X is a portion of the protruding portion 460B that has been processed to be thin. The position at which the broken portion 460X is formed in the protruding portion 460B can be selected arbitrarily. In this embodiment, the broken portion 460X is formed in the middle portion of the protruding portion 460B. The broken portion 460X may be formed in the base of the protruding portion 460B. In the manufacturing process of the electricity storage device 10, the position of the protruding portion 460B relative to the electrode body 20 is fixed by a fixing jig 471. The movement of the electrode body 20 is restricted by a fixing jig 472. After, for example, a ninth step (see FIG. 7) of the manufacturing process of the electricity storage device 10 is completed, the fixing jig 471 is removed from the protruding portion 460B, and the protruding portion 460B is broken at the breaking portion 460X. Since the protruding portion 460B is shortened, the volume of the lid body 460 and the volume of the electricity storage device 10 can be reduced. As a result, the energy density of the electricity storage device 10 can be increased.

[0109] <2-2> In the above embodiment, the configuration of the lid fixing part 110 of the fixing jig 100 can be changed arbitrarily. Fig. 24 is a perspective view of a modified lid fixing part 510. The lid fixing part 510 can be used to fix the lid body 360 shown in Fig. 22, for example.

[0110] The lid fixing part 510 has a first fixing part 511 and a second fixing part 512 configured to sandwich the protruding part 360B. The first fixing part 511 has three recesses 511A recessed on the side opposite to the second fixing part 512. The second fixing part 512 has three recesses 512A recessed on the side opposite to the first fixing part 511. The protruding part 360B is sandwiched and fixed between the recesses 511A and 512A facing each other. Of the three recesses 511A, it is preferable that the cushioning material 520 is disposed in the recesses 511A at both ends. It is preferable that the cushioning material 520 has flexibility so as to deform along the shape of the protruding part 360B. Since the cushioning material 520 can flexibly deform according to the shape of the protruding part 360B when sandwiching the protruding part 360B, even if there is some individual difference in the shape of the protruding part 360B, the protruding part 360B can be suitably fixed. In addition, the protruding portion 360B is less likely to be damaged since it is protected by the cushioning material 520. The number of recesses 511A, 512A formed in the lid fixing portion 510 can be changed as desired depending on the number of protruding portions 360B of the lid body 360 to be fixed.

[0111] <2-3> In the above embodiment, as shown in FIG. 25, from the viewpoint of increasing the adhesion between the exterior film 50 and the electrode body 20, a belt-shaped member 700 that is bonded to the inner surface of the exterior film 50 may be wound around the electrode body 20. Any material may be used for the material constituting the belt-shaped member 700. For example, the belt-shaped member 700 may be a sheet made of an olefin resin. The belt-shaped member 700 may be bonded to the inner surface of the exterior film 50 by an adhesive or the like, or may be bonded to the inner surface of the exterior film 50 by heat sealing. The belt-shaped member 700 may or may not be bonded to the electrode body 20. From the viewpoint of further increasing the adhesion between the exterior film 50 and the electrode body 20, it is preferable that the belt-shaped member 700 is bonded to the electrode body 20. The position at which the belt-shaped member 700 is wound around the electrode body 20 can be selected arbitrarily. In the example shown in FIG. 25, the belt-shaped member 700 is wound around the electrode body 20 approximately at the center in the FB direction. In this modified example, the protrusion 60B of the lid 60 may be omitted.

[0112] <2-4> In the above embodiment, the third step (winding step) of the manufacturing method for the electricity storage device 10 can be changed as desired. For example, in the above embodiment, the size of the exterior film 50 used in the third step is a size that does not protrude from the seal surface 63 of the lid body 60 in the FB direction. However, as shown in Fig. 26, the exterior film 50 may have an excess portion 50X that protrudes from the seal surface 63 of the lid body 60. The excess portion 50X is preferably cut or folded in an arbitrary direction in an arbitrary step performed after the winding step.

[0113] <2-5> In the above embodiment, the fifth step (sealing step) of the manufacturing method of the electricity storage device 10 can be selected arbitrarily. For example, in the fifth step, from the viewpoint of enhancing the sealing property of the boundaries 64 to 67 of the lid body 60, it is preferable to sequentially join adjacent sealing surfaces of the lid body 60. For example, as shown in FIG. 27, when a seal bar 610 of a heat sealing device is used, it is preferable to join the exterior film 50 to the first sealing surface 63A, the third sealing surface 63C, the fourth sealing surface 63D, and the second sealing surface 63B in this order. In another example, the second sealing surface 63B, the fourth sealing surface 63D, the third sealing surface 63C, and the first sealing surface 63A may be joined to the exterior film 50 in this order. The first sealing surface 63A and the fourth sealing surface 63D may be heat-sealed before the second sealing surface 63B and the third sealing surface 63C of the lid body 60.

[0114] In the fifth step (sealing step), the second sealing portion 80 may be formed by a heat sealing device. In this modification, it is preferable to control the amount of pressing of the seal bar 610 of the heat sealing device against the exterior film 50 and the lid body 60. When the pressure of the seal bar 610 is controlled, the heat-sealable resin layer 53 of the exterior film 50 may melt excessively, and a poly pool may be formed between the seal surface 63 of the lid body 60 and the exterior film 50. The poly pool may cause cracks to occur in the exterior body 40. For this reason, it is preferable to control the amount of pressing of the seal bar 610 so that the heat-sealable resin layer 53 does not melt excessively. The amount of pressing of the seal bar 610 is the distance that the seal bar 610 approaches the lid body 60 from the reference position, with the position where the seal bar 610 and the surface of the exterior film 50 come into contact as the reference position. It is preferable that the amount of pressing is, for example, about half the thickness of the heat-sealable resin layer 53.

[0115] The amount of pressing of the seal bar 610 can be controlled by, for example, an electric cylinder 800 connected to the seal bar 610 shown in Fig. 28. A known electric cylinder can be used as the electric cylinder 800. The electric cylinder 800 includes a main body 810 including a motor and the like, and a rod 820 whose protruding amount relative to the main body 810 changes. The seal bar 610 is fixed to the tip of the rod 820.

[0116] FIG. 28 is a diagram showing the initial position of the seal bar 610. FIG. 29 is a diagram showing the reference position of the seal bar 610. As shown in FIG. 28, in the initial position of the seal bar 610, the seal bar 610 is separated from the exterior film 50 and the lid body 60. In the initial position, the protruding amount of the rod 820 relative to the main body 810 increases, so that the seal bar 610 approaches the exterior film 50 and the lid body 60, and reaches the reference position shown in FIG. 29. Note that, instead of the electric cylinder 800, the pushing amount of the seal bar 610 may be controlled by an air cylinder connected to the seal bar 610. When an air cylinder is used instead of the electric cylinder 800, in order to prevent the seal bar 610 from being pushed in beyond a preset pushing amount, it is preferable that a regulating member that cushions the seal bar 610 at a position of a preset pushing amount is arranged around the intermediate body.

[0117] In addition, from the viewpoint of suppressing the formation of a polymer pool, it is preferable that the second sealing portion 80 is formed in as short a time as possible. For this reason, in the above embodiment, it is preferable that the lid body 60 is preheated in an arbitrary step performed before the fifth step. By preheating the lid body 60, for example, even if the melting point of the material constituting the lid body 60 is equal to or higher than the melting point of the material constituting the heat-sealable resin layer 53 of the exterior film 50, the second sealing portion 80 can be formed in a short time. Depending on the method of forming the second sealing portion 80, the first sealing surface 63A, the second sealing surface 63B, the third sealing surface 63C, and the fourth sealing surface 63D may be heated simultaneously or in any order. The lid body 60 can be heated by any means, such as a heater bar, ultrasonic waves, or an infrared lamp.

[0118] The surface of the sealing surface 63 of the lid body 60 may have minute irregularities, for example. Therefore, when the second sealing portion 80 is formed by a heat sealing device, the sealing strength may vary for each part of the second sealing portion 80. Furthermore, the size of the poly pool formed between the exterior film 50 and the lid body 60 may also vary. From the viewpoint of reducing the variation in the sealing strength and the variation in the size of the poly pool, when a heat sealing device is used in the fifth step, it is preferable to form the second sealing portion 80 in a state in which a heat-resistant elastic body 910 is sandwiched between the seal bar 610 and the exterior film 50, as shown in FIG. 30. The material constituting the elastic body 910 is an elastic body having a melting point equal to or higher than the temperature of the heat sealing conditions. The material constituting the elastic body 910 is, for example, a rubber sheet, a silicone sheet, a urethane sheet, or a fluororesin sheet.

[0119] Similarly, from the viewpoint of reducing the variation in the seal strength of the second sealing portion 80, when a heat sealing device is used in the fifth step, it is preferable to form the second sealing portion 80 with at least the lid body 60 placed on the elastic body 920. The electrode body 20 may be placed on the elastic body 920. The material constituting the elastic body 920 may be a sponge in addition to the materials exemplified as the material constituting the elastic body 910. In the example shown in FIG. 30, the elastic body 910 or the elastic body 920 may be omitted.

[0120] <2-6> In the above embodiment, the first step and the second step can be arbitrarily modified in the manufacturing method of the power storage device 10. Fig. 31 is a flowchart showing a modified example of the manufacturing method of the power storage device 10. The modified example of the manufacturing method of the power storage device 10 includes a 31st step and a 32nd step.

[0121] In a 31st step (connecting step) of step S31, the manufacturing equipment connects the electrode body 20 and the electrode terminal 30 together.

[0122] The 32nd step (arrangement step) of step S32 is performed after the 31st step. In the 32nd step, the manufacturing equipment arranges the lid bodies 60 on both ends of the electrode body 20. FIG. 32 is a diagram relating to the 32nd step. Hereinafter, the electrode terminal 30 and the lid body 60 arranged on one side of the electrode body 20 are referred to as the electrode terminal 30L and the lid body 60L, respectively. The electrode terminal 30 and the lid body 60 arranged on the other side of the electrode body 20 are referred to as the electrode terminal 30R and the lid body 60R, respectively.

[0123] The manufacturing equipment uses an image processing device (not shown) to position one lid body 60L relative to one electrode terminal 30L. As shown in FIG. 31, in the arrangement process, for example, the positioning of one lid body 60L relative to one electrode terminal 30L is performed based on the long side PAX and short side PBX of one electrode terminal 30L in a plan view. The image processing device detects the short side PBX by transmission inspection, and calculates the amount of correction with respect to the reference side on the opposite side from the position information. Next, the manufacturing equipment performs positioning of the other lid body 60R relative to the other electrode terminal 30R based on the long side PAX and short side PBX of one electrode terminal 30L.

[0124] In positioning the other lid body 60R, the other lid body 60R may be positioned relative to the other electrode terminal 30R based on the long side PAY and short side PBY of the other electrode terminal 30R in a plan view. In the third step (winding step), the exterior film 50 may be positioned relative to the intermediate body based on the long side PAX and short side PBX or the long side PAY and short side PBY set in the arrangement step.

[0125] <2-7> In the above embodiment, the lid body 60 may be formed with a recess recessed from the second surface 62 toward the first surface 61 in addition to or instead of the protruding portion 60B. The lid body 60 is fixed by inserting the protruding portion of the fixing jig 100 into the recess.

[0126] <2-8> In the above embodiment, the cover 60 may be formed with at least one of a protrusion protruding from the first surface 61 and a recess recessed from the first surface 61 toward the second surface 62. The electrode body 20 is fixed by at least one of the protrusion and the recess formed on the first surface 61. In addition, the shape of the electrode body 20 is maintained by at least one of the protrusion and the recess formed on the first surface 61.

[0127] <2-9> In the above embodiment, the exterior film 50 of the electricity storage device 10 may protrude outward beyond the lid body 60 in the FB direction. The portion of the exterior film 50 protruding beyond the lid body 60 may be folded like a Gabeltop pouch or a brick pouch. [Explanation of symbols]

[0128] 10: Energy storage device 20: Electrode body 30: Electrode terminal 40: Exterior body 40A: Opening 50: Exterior film 50X: Excess 60, 260, 360, 460: Lid 80: Second sealing portion (sealing portion) 910, 920: Elastic body

Claims

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 so as to form an opening; A lid for closing the opening; a sealing portion in which the lid body and the exterior film are joined, The lid has a plurality of sealing surfaces to be joined to the exterior film, The method for manufacturing the electricity storage device includes: a winding step of winding the exterior film around the electrode body; A sealing step of forming the sealing portion, In the winding step, The exterior film is wrapped around the electrode body so that a protruding portion of the exterior film is formed, the protruding portion protruding outward beyond the electrode body; In the sealing step, adjacent seal surfaces among the plurality of seal surfaces are sequentially joined by a sealing device. A method for manufacturing an electricity storage device.

2. The plurality of sealing surfaces are A first sealing surface that constitutes an upper surface of the lid; a second seal surface and a third seal surface that are connected to the first seal surface and that constitute side surfaces of the lid body; a fourth seal surface that is connected to the second seal surface and the third seal surface and that constitutes a lower surface of the lid body, In the sealing step, the first seal surface, the third seal surface, the fourth seal surface, and the second seal surface are joined in this order. A method for producing the electricity storage device according to claim 1 .

3. The plurality of sealing surfaces are A first sealing surface that constitutes an upper surface of the lid; a second seal surface and a third seal surface that are connected to the first seal surface and that constitute side surfaces of the lid body; a fourth seal surface that is connected to the second seal surface and the third seal surface and that constitutes a lower surface of the lid body, In the sealing step, the second seal surface, the fourth seal surface, the third seal surface, and the first seal surface are joined in this order. A method for producing the electricity storage device according to claim 1 .

4. In the sealing process, the sealing portion is formed by two sealing devices. A method for producing the electricity storage device according to claim 1 .

5. The plurality of sealing surfaces are A first sealing surface that constitutes an upper surface of the lid; a second seal surface and a third seal surface that are connected to the first seal surface and that constitute side surfaces of the lid body; a fourth seal surface that is connected to the second seal surface and the third seal surface and that constitutes a lower surface of the lid body, In the sealing step, One of the two seal devices joins the third seal surface and the first seal surface in this order. The method for producing the electricity storage device according to claim 4 .

6. The lid body has a boundary between the fourth sealing surface and the third sealing surface, In the sealing step, one of the two sealing devices starts moving from the boundary. A method for producing the electricity storage device according to claim 5 .

7. The plurality of sealing surfaces are A first sealing surface that constitutes an upper surface of the lid; a second seal surface and a third seal surface that are connected to the first seal surface and that constitute side surfaces of the lid body; a fourth seal surface that is connected to the second seal surface and the third seal surface and that constitutes a lower surface of the lid body, In the sealing step, The other of the two sealing devices joins the fourth seal surface and the second seal surface in this order. A method for producing the electricity storage device according to any one of claims 4 to 6.

8. The lid body has a boundary between the fourth seal surface and the third seal surface, In the sealing step, one of the two sealing devices starts moving from the boundary. A method for producing the electricity storage device according to claim 7 .

9. The plurality of sealing surfaces are A first sealing surface that constitutes an upper surface of the lid; a second seal surface and a third seal surface that are connected to the first seal surface and that constitute side surfaces of the lid body; a fourth seal surface that is connected to the second seal surface and the third seal surface and that constitutes a lower surface of the lid body, In the sealing step, the sealing device starts moving from a middle portion of the first seal surface, a middle portion of the second seal surface, a middle portion of the third seal surface, or a middle portion of the fourth seal surface. A method for producing the electricity storage device according to any one of claims 1 to 3.

10. In the sealing process, adjacent sealing surfaces of the plurality of sealing surfaces of the lid body wrapped in the exterior film are sequentially joined. A method for producing the electricity storage device according to any one of claims 1 to 6.

11. The sealing step includes a first sealing step of forming the sealing portion while moving one of the sealing device and the lid body relative to the other. A method for producing the electricity storage device according to any one of claims 1 to 6.

12. The sealing device is an ultrasonic sealing device or a welding machine. A method for producing the electricity storage device according to any one of claims 1 to 6.

13. The sealing device is a heat sealing device using a roller or a heat sealing device using a seal bar. A method for producing the electricity storage device according to any one of claims 1 to 6.

14. In the winding step, The protruding portion is pulled in any direction relative to the electrode body with a predetermined strength, The predetermined strength is a strength that is included in a range in which the stress and strain acting on the exterior film suppresses the occurrence of wrinkles and sagging in the exterior film. A method for producing the electricity storage device according to any one of claims 1 to 6.

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