Power storage device, exterior packaging film, and method for manufacturing power storage device

Abstract

To provide a power storage device with high sealability, an exterior film for use in the power storage device, and a method for manufacturing the power storage device.SOLUTION: A power storage device comprises an electrode body, and an exterior body for sealing the electrode body. The exterior body has an exterior film for wrapping the electrode body, and a lid body for sealing the electrode body together with the exterior film. The exterior film includes a barrier layer comprising a metal material. The lid body includes a portion including a metal material. The barrier layer of the exterior film and the portion including the metal material, of the lid body are directly joined together.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a power storage device, an exterior film, and a method for manufacturing a power storage device.

Background Art

[0002] Patent Document 1 discloses an example of a power storage device. This power storage device includes an electrode body and an exterior body that seals the electrode body. The exterior body includes an exterior film that wraps the electrode body and a lid body that is joined to the exterior film. The exterior film and the lid body are joined by heat sealing.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above power storage device, there is a risk that moisture may enter the interior of the exterior body from between the exterior film and the lid body. Therefore, there is still room for improvement in the moisture barrier property of the above power storage device.

[0005] An object of the present invention is to provide a power storage device having high moisture barrier properties, an exterior film used for this power storage device, and a method for manufacturing this power storage device.

Means for Solving the Problems

[0006] The power storage device according to the first aspect of the present invention includes an electrode body and an exterior body that seals the electrode body. The exterior body has an exterior film that wraps the electrode body and a lid body that seals the electrode body together with the exterior film. The exterior film includes a barrier layer composed of a metal material, the lid body includes a portion composed of a metal material, and the barrier layer of the exterior film and the portion of the lid body composed of the metal material are directly joined.

[0007] The power storage device according to the second aspect of the present invention is the power storage device according to the first aspect, and a portion of the exterior film that is joined to the portion of the lid body composed of the metal material is a single layer of the barrier layer.

[0008] The power storage device according to the third aspect of the present invention is the power storage device according to the first aspect, the exterior film includes other layers laminated on the barrier layer, and a portion of the exterior film that is joined to the portion of the lid body composed of the metal material is a portion where the barrier layer is partially exposed from the other layers.

[0009] The power storage device according to the fourth aspect of the present invention is the power storage device according to any one of the first to third aspects. The lid body has a covering body and a lid main body joined to the covering body. At least one of the covering body and the lid main body is composed of a metal material. The exterior body has a sealing portion in which the exterior film is sandwiched between the covering body and the lid main body. The barrier layer of the exterior film is directly joined to the portion of the covering body and the lid main body composed of the metal material at the sealing portion.

[0010] The exterior film according to the fifth aspect of the present invention is an exterior film used as an exterior body of a power storage device. The exterior body has a lid body composed of a metal material. The exterior film includes a barrier layer composed of a metal material. A portion of the lid body that is joined to the portion composed of the metal material is a single layer of the barrier layer, or the barrier layer is partially exposed from other layers.

[0011] The method for manufacturing a power storage device according to the sixth aspect of the present invention includes an electrode body and an exterior body that seals the electrode body. The exterior body has an exterior film that wraps the electrode body and a lid body that seals the electrode body together with the exterior film. The exterior film includes a barrier layer formed of a metal material, and the lid body includes a portion formed of a metal material. The method for manufacturing a power storage device includes a step of directly joining the barrier layer of the exterior film and the portion of the lid body formed of the metal material.

Advantages of the Invention

[0012] According to the power storage device, exterior film, and method for manufacturing a power storage device of the present invention, the moisture barrier property is high.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4A

Figure 4B

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0014] Hereinafter, with reference to the drawings, a power storage device according to an embodiment of the present invention will be described. In this specification, the numerical range indicated by "~" means "or more" and "or less". For example, the notation of 2~15 mm means 2 mm or more and 15 mm or less.

[0015] [1. Embodiment] <1-1. Configuration of the Power Storage Device> FIG. 1 is a perspective view schematically showing the power storage device 10 of the embodiment. FIG. 2 is a cross-sectional view showing an example of the layer structure of the exterior film 50 included in the power storage device 10 of FIG. 1. FIG. 3 is a view of the exterior film 50 included in the power storage device 10 of FIG. 1 in a spread state. FIG. 4A is a perspective view of the covering body 70 included in the power storage device 10 of FIG. 1. FIG. 4B is a cross-sectional view taken along the line D4B-D4B of FIG. 4A. FIG. 5 is a perspective view of the lid body 80 included in the power storage device 10 of FIG. 1. FIG. 6 is a front view of the power storage device 10 of FIG. 1. FIG. 7 is a cross-sectional view taken along the line D7-D7 of FIG. 1. In FIG. 1, the direction of the arrow UD indicates the thickness direction of the power storage device 10, the direction of the arrow LR indicates the width direction of the power storage device 10, and the direction of the arrow FB indicates the depth direction of the power storage device 10. The directions indicated by each of the arrows UDLRFB are common in the following figures.

[0016] The power storage device 10 includes an electrode body 20 including a current collector 30 (see FIG. 7) and an exterior body 40. The electrode body 20 includes, for example, electrodes (a positive electrode and a negative electrode) constituting a power storage member such as a lithium ion battery, a capacitor, an all-solid-state battery, a semi-solid-state battery, a quasi-solid-state battery, a polymer battery, an all-resin battery, a lead storage battery, a nickel-hydrogen storage battery, a nickel-cadmium storage battery, a nickel-iron storage battery, a nickel-zinc storage battery, a silver oxide-zinc storage battery, a metal-air battery, a polyvalent cation battery, or a capacitor, as well as a separator and the like. In the present embodiment, the shape of the electrode body 20 is substantially a rectangular parallelepiped. Note that the "substantially rectangular parallelepiped" includes, in addition to a perfect rectangular parallelepiped, a solid 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.

[0017] The exterior body 40 seals the electrode body 20. The exterior body 40 includes an exterior film 50 and a lid body 60. In the present embodiment, the exterior film 50 is wound around the electrode body 20. Note that the electrode body 20 may be housed inside the cylindrically configured exterior film 50. The exterior body 40 has a pair of first surfaces 41A and 41B and a pair of second surfaces 42A and 42B. In the present embodiment, the pair of first surfaces 41A and 41B are substantially the same size. In the present embodiment, the pair of second surfaces 42A and 42B are substantially the same size. The pair of first surfaces 41A and 41B have a larger area than the pair of second surfaces 42A and 42B. The pair of lid bodies 60 are respectively disposed on the sides of the electrode body 20.

[0018] For example, there is a method of forming a depression for accommodating the electrode body 20 in the exterior film 50 through cold forming. However, it is not always easy to form a deep depression by such a method. When attempting to deeply form a depression (for example, a forming depth of 15 mm) by cold forming, pinholes or cracks are likely to occur in the exterior film 50, increasing the possibility of deterioration of battery performance. On the other hand, since the exterior body 40 seals the electrode body 20 by winding the exterior film 50 around the electrode body 20, 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, a state where the exterior film 50 is wound so as to contact the outer surface of the electrode body 20 is preferable. Also, in a all-solid-state battery, from the viewpoint that it is necessary to uniformly apply a high pressure from the outer surface of the battery to exhibit battery performance, it is necessary to eliminate the space between the electrode body 20 and the exterior film 50, so a state where the exterior film 50 is wound so as to contact the outer surface of the electrode body 20 is preferable.

[0019] As shown in FIG. 2, the exterior film 50 is, for example, a laminate (laminate film) having a base material layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in this order. Note that it is not necessary for the exterior film 50 to include all of these layers, and it is sufficient if at least the barrier layer 52 is included. That is, the exterior film 50 may be made of a material having flexibility and being easy to bend, and may be made of, for example, a resin film. Note that 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.

[0020] The overall thickness of the exterior film 50 can be arbitrarily selected. From the perspective of strength, the thickness of the exterior film 50 is preferably 50 μm or more. From the perspective of formability or followability, the thickness of the exterior film 50 is preferably 1200 μm or less. The thickness of the exterior film 50 preferably falls within the range of 50 μm to 1200 μm.

[0021] The base material layer 51 included in the exterior film 50 is a layer that imparts heat resistance to the exterior film 50 and suppresses the occurrence of pinholes that may occur during processing or distribution. The base material layer 51 is composed of, for example, at least one of a stretched polyester resin layer and a stretched polyamide resin layer. For example, by including at least one of a stretched polyester resin layer and a stretched polyamide resin layer in the base material layer 51, the barrier layer 52 can be protected during processing of the exterior film 50, and breakage of the exterior film 50 can be suppressed. Also, from the perspective of increasing the tensile elongation of the exterior film 50, the stretched polyester resin layer is preferably a biaxially stretched polyester resin layer, and the stretched polyamide resin layer is preferably a biaxially stretched polyamide resin layer. Furthermore, from the point 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. Note that the base material layer 51 may be composed of both a stretched polyester resin layer and a stretched polyamide resin layer. From the point of film strength, the thickness of the base material layer 51 is preferably, for example, 5 to 300 μm, and more preferably 5 to 150 μm.

[0022] The barrier layer 52 is a layer that suppresses at least the ingress of moisture. The barrier layer 52 is joined to the base material layer 51 via, for example, an adhesive layer 54. Examples of the barrier layer 52 include a metal foil having barrier properties, a vapor deposition film, a resin layer, and the like. Examples of the vapor deposition film include a metal vapor deposition film, an inorganic oxide vapor deposition film, a carbon-containing inorganic oxide vapor deposition film, and the like. Examples of the resin layer include polyvinylidene chloride, polymers mainly composed of chlorotrifluoroethylene (CTFE), polymers mainly composed of tetrafluoroethylene (TFE), polymers having a fluoroalkyl group, fluorine-containing resins such as polymers mainly composed of fluoroalkyl units, and ethylene vinyl alcohol copolymers. Further, examples of the barrier layer 52 include a resin film provided with at least one of these vapor deposition films and resin layers. A plurality of barrier layers 52 may be provided. In the present embodiment, 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 steels, titanium steels, steel plates, and the like. When used as a metal foil, it preferably includes at least one of an aluminum alloy foil and a stainless steel foil.

[0023] In the barrier layer 52, the layer made of the above-described metal material may contain a recycled material of the metal material. Examples of the recycled material of the metal material include recycled materials of aluminum alloys, stainless steels, titanium steels, or steel plates. These recycled materials can be obtained by known methods respectively. The recycled material of the aluminum alloy can be obtained, for example, by the production method described in International Publication No. 2022 / 092231. The barrier layer 52 may be composed only of the recycled material, or may be composed of a mixed material of the recycled material and the virgin material. The recycled material of the metal material refers to a metal material that has been recovered, isolated, refined, etc. from various products used in the market, waste from the manufacturing process, etc. and made reusable. The virgin material of the metal material refers to a new metal material refined from natural resources (raw materials) of the metal and not a recycled material.

[0024] From the perspective of improving the formability or followability of the exterior film 50, the aluminum alloy foil is more preferably a soft aluminum alloy foil composed of, for example, an annealed aluminum alloy, and from the perspective of further improving the formability or followability, it is preferably an aluminum alloy foil containing iron. In the aluminum alloy foil containing iron (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. When the iron content is 0.1% by mass or more, an exterior film 50 having better formability can be obtained. When the iron content is 9.0% by mass or less, an exterior film 50 having better flexibility can be obtained. Also, if necessary, silicon, magnesium, copper, manganese, etc. may be added. Softening can be performed by annealing treatment or the like. From the perspective of improving the mechanical strength of the exterior film 50, the aluminum alloy foil is more preferably a hard aluminum alloy foil composed of, for example, a work-hardened aluminum alloy. Examples of the hard aluminum alloy foil include aluminum alloy foils having compositions defined in JIS H4160:1994 A8021H-H18, JIS H4160:1994 A8079H-H18, JIS H4000:2014 A8021P-H14, or JIS H4000:2014 A8079P-H14. From the perspective of improving the mechanical strength of the exterior film 50, the aluminum alloy foil is preferably an aluminum alloy foil containing magnesium. In the aluminum alloy foil containing magnesium (100% by mass), the magnesium content is preferably 0.2 to 5.6% by mass, and more preferably 0.2 to 3.0% by mass. Examples of the aluminum alloy foil containing magnesium include aluminum alloy foils having compositions defined in JIS H4000:2017 A5005P-O, JIS H4000:2017 A5050P-O, JISH4000:2017 A5052P-O.

[0025] Examples of the stainless steel foil include austenitic, ferritic, austenitic-ferritic, martensitic, and precipitation hardening stainless steel foils. Further, from the viewpoint of providing the exterior film 50 having excellent formability, the stainless steel foil is preferably composed of austenitic stainless steel.

[0026] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L, etc. Among these, SUS304 is particularly preferable.

[0027] In the case of a metal foil, the thickness of the barrier layer 52 only needs to function as a barrier layer that at least suppresses the ingress of moisture, and for example, it can be about 5 to 1000 μm. The thickness of the barrier layer 52 is preferably about 85 μm or less, more preferably about 50 μm or less, still more preferably about 40 μm or less, and particularly preferably about 35 μm or less. Also, the thickness of the barrier layer 52 is preferably about 9.0 μm or more, still more preferably about 20 μm or more, and more preferably about 25 μm or more. Also, the preferable range of the thickness of the barrier layer 52 includes about 9.0 to 1000 μm, about 9.0 to 1000 μm, about 9.0 to 1000 μm, about 9.0 to 1000 μm, about 9.0 to 85 μm, about 9.0 to 50 μm, about 9.0 to 40 μm, about 9.0 to 35 μm, about 20 to 85 μm, about 20 to 50 μm, about 20 to 40 μm, about 20 to 35 μm, about 25 to 85 μm, about 25 to 50 μm, about 25 to 40 μm, about 25 to 35 μm. When the barrier layer 52 is formed of an aluminum alloy foil, the above-described range is particularly preferable. Also, 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, still more preferably about 50 μm or more, and still more preferably about 55 μm or more. Also, it is preferably about 200 μm or less, more preferably about 85 μm or less, still more preferably about 75 μm or less, and still more preferably about 70 μm or less. The preferable range includes 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, about 55 to 70 μm. When the exterior film 50 has high formability, deep drawing forming becomes easy, which can contribute to increasing the capacity of the power storage device. Also, when the capacity of the power storage device is increased, the weight of the power storage device increases, but by increasing the rigidity of the exterior film 50, it can contribute to high sealing performance of the power storage device.In particular, when the barrier layer 52 is made of a stainless steel foil, the thickness of the stainless steel foil is preferably about 60 μm or less, more preferably about 50 μm or less, still more preferably about 40 μm or less, still more preferably about 30 μm or less, and particularly preferably about 25 μm or less. Also, the thickness of the stainless steel foil is preferably about 10 μm or more, more preferably about 15 μm or more. Also, the preferable range of the thickness of the stainless steel foil includes 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.

[0028] When the barrier layer 52 is an aluminum foil, in order to prevent dissolution and corrosion, etc., it is preferable to provide a corrosion-resistant film on at least the surface opposite to the base material layer 51. The barrier layer 52 may be provided with corrosion-resistant films on both sides. Here, the corrosion-resistant film refers to, for example, a thin film that is formed by performing a hot water conversion treatment such as a boehmite treatment, a chemical conversion treatment, an anodizing treatment, a plating treatment such as nickel or chromium, or a corrosion prevention treatment of applying a coating agent on the surface of the barrier layer 52 to provide the barrier layer 52 with corrosion resistance (such as acid resistance, alkali resistance, etc.). Specifically, the corrosion-resistant film means 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. As the treatment for forming the corrosion-resistant film, one type may be performed, or two or more types may be combined. Also, it can be made into multiple layers instead of just one layer. Furthermore, among these treatments, the hot water conversion treatment and the anodizing treatment are treatments that dissolve the surface of the metal foil with a treatment agent to form a metal compound having excellent corrosion resistance. Note that these treatments may be included in the definition of the chemical conversion treatment. Also, when the barrier layer 52 is provided with a corrosion-resistant film, the barrier layer 52 including the corrosion-resistant film is used.

[0029] The corrosion-resistant film prevents delamination between the barrier layer 52 (e.g., aluminum alloy foil) and the base material layer 51 during the molding of the outer packaging film 50, and prevents dissolution and corrosion of the surface of the barrier layer 52 due to hydrogen fluoride generated by the reaction of the electrolyte and moisture, particularly 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. In addition, it improves the adhesiveness (wettability) of the surface of the barrier layer 52, and shows the effect of preventing delamination between the base material layer 51 and the barrier layer 52 during heat sealing and preventing delamination between the base material layer 51 and the barrier layer 52 during molding.

[0030] The heat-sealable resin layer 53 is joined to the barrier layer 52 via, for example, the adhesive layer 55. The heat-sealable resin layer 53 contained in the outer packaging film 50 is a layer that imparts heat-sealing properties to the outer packaging film 50. Examples of the heat-sealable resin layer 53 include resin films made of polyester resins such as polyethylene terephthalate-based resins and polybutylene terephthalate-based resins, polyolefin resins such as polyethylene-based resins and polypropylene-based resins, or acid-modified polyolefin resins obtained by graft-modifying these polyolefin resins with an acid such as maleic anhydride. From the viewpoints of sealing properties and strength, the thickness of the heat-sealable resin layer 53 is preferably, for example, 20 to 300 μm, and more preferably 40 to 150 μm.

[0031] The outer packaging film 50 preferably has one or more layers having a buffering 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 outside the base material layer 51, or the base material layer 51 may also serve as the buffer layer. When the outer packaging film 50 has a plurality of buffer layers, the plurality of buffer layers may be adjacent to each other, or may be laminated via the base material layer 51 or the barrier layer 52 or the like.

[0032] The material constituting the buffer layer can be arbitrarily selected from materials having cushioning properties. Materials having cushioning properties are, for example, rubber, non-woven fabric, or foamed 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 non-woven fabric is preferably a material having excellent heat resistance. When the buffer layer is constituted by a non-woven fabric, the lower limit value of the thickness of the buffer layer is preferably 100 μm, more preferably 200 μm, and even more preferably 1000 μm. When the buffer layer is constituted by a non-woven fabric, the upper limit value of the thickness of the buffer layer is preferably 5000 μm, more preferably 3000 μm. The preferable range of the thickness of the buffer layer is 100 μm to 5000 μm, 100 μm to 3000 μm, 200 μm to 5000 μm, 200 μm to 3000 μm, 1000 μm to 5000 μm, or 1000 μm to 3000 μm. Among these, the range of the thickness of the buffer layer is most preferably 1000 μm to 3000 μm.

[0033] When the buffer layer is constituted by rubber, the lower limit value of the thickness of the buffer layer is preferably 0.5 mm. When the buffer layer is constituted by rubber, the upper limit value of the thickness of the buffer layer is preferably 10 mm, more preferably 5 mm, and even more preferably 2 mm. When the buffer layer is constituted by rubber, the preferable 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.

[0034] When the exterior film 50 has a buffer layer, since the buffer layer functions as a cushion, it is possible to suppress the exterior film 50 from being damaged due to the impact when the power storage device 10 falls or due to the handling during the manufacture of the power storage device 10.

[0035] The lid body 60 has a covering body 70 and a lid main body 80.

[0036] The covering body 70 shown in FIG. 4 has a shape similar to, for example, a hollow rectangular parallelepiped. A space 79 is formed inside the covering body 70. The material constituting the covering body 70 can be arbitrarily selected. From the viewpoint of preferably forming the second sealing portion 92 described later, the covering body 70 is preferably composed of a metal material. Here, "composed of a metal material" means that when the total amount of the material constituting the covering body 70 is 100% by mass, the content of the metal material is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. That is, the material constituting the covering body 70 can contain materials other than the metal material in addition to the metal material. The metal material constituting the covering body 70 can be arbitrarily selected. The metal material constituting the covering body 70 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 covering body 70 connected to the positive electrode is preferably composed of aluminum or an aluminum alloy. The covering body 70 connected to the negative electrode is preferably composed of nickel, copper, or a copper alloy. The material constituting the covering body 70 connected to the negative electrode may be copper with nickel plating. The material constituting the covering body 70 may contain a recycled material of the metal material. In the present embodiment, the covering body 70 is composed of only a metal material. Since the covering body 70 is composed of a metal material, it also serves as an electrode terminal. Therefore, the configuration of the power storage device 10 can be simplified. When the covering body 70 is composed of a metal material, the covering body 70 preferably has a corrosion-resistant film described in the barrier layer 52.

[0037] In another example, the covering body 70 may be composed of a resin material. Here, "composed of a resin material" means that when the total amount of the material constituting the covering body 70 is 100% by mass, the content of the resin material is 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more. That is, the material constituting the covering body 70 can contain materials other than the resin material in addition to the resin material.

[0038] Specific examples of the resin include resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenol resin, and thermoplastic resins such as modified products of these resins. Further, the resin material may be a mixture of these resins, a copolymer, or a modified product of a copolymer. Among these, the resin material is preferably a heat-sealable resin such as polyester or polyolefin, and more preferably polyolefin. When the resin material is a resin, the joint portion 80B may be formed by any molding method.

[0039] The resin material contained in the material constituting the covering 70 is preferably an olefin-based random copolymer, more preferably contains a resin containing a polyolefin skeleton as a main component, still more preferably contains polyolefin as a main component, and still more preferably contains polypropylene as a main component. The polyolefin may be an acid-modified polyolefin. It is preferable that a plurality of types of amide-based lubricants are present in the resin material contained in the material constituting the covering 70. Further, it is preferable that the resin material contained in the material constituting the covering 70 further contains an unsaturated fatty acid amide in addition to the saturated fatty acid amide and a plurality of types of amide-based lubricants. The resin material contained in the material constituting the covering 70 may be a polyolefin resin added with a propylene-based elastomer having a melting point higher than 150°C.

[0040] Examples of the polyester include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polyethylene isophthalate, and copolyester. Examples of the copolyester include copolyesters having ethylene terephthalate as the main repeating unit. Specifically, copolyester polyethylenes (hereinafter abbreviated following polyethylene(terephthalate / isophthalate)) obtained by polymerizing ethylene isophthalate with ethylene terephthalate as the main repeating unit, polyethylene(terephthalate / adipate), polyethylene(terephthalate / sodium sulfoisophthalate), polyethylene(terephthalate / sodium isophthalate), polyethylene(terephthalate / phenyl-dicarboxylate), polyethylene(terephthalate / decanedicarboxylate), etc. are included. Among these, the resin material is preferably polybutylene terephthalate from the viewpoint of enhancing heat resistance and pressure resistance.

[0041] Examples of the polyolefin include polyethylenes such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; ethylene-α-olefin copolymers; polypropylenes such as homopolypropylene, block copolymers of polypropylene (e.g., block copolymers of propylene and ethylene), and random copolymers of polypropylene (e.g., random copolymers of propylene and ethylene); propylene-α-olefin copolymers; and terpolymers of ethylene-butene-propylene. The polyolefin resin in the case of being a copolymer may be a block copolymer or a random copolymer. Among these, the resin material is preferably polypropylene because of its excellent heat sealing property and electrolyte resistance.

[0042] The resin as the resin material may contain a filler as required. Specific examples of the filler include glass beads, graphite, glass fibers, and carbon fibers. By the resin as the resin material containing the filler, the deformation resistance of the joint portion 80B against temperature changes can be improved.

[0043] The melt mass flow rate of the resin material contained in the material constituting the covering 70 is preferably in the range of 1 g / 10 min to 100 g / 10 min, and more preferably in the range of 5 g / 10 min to 80 g / 10 min. The melt mass flow rate is measured based on JIS K7210-1:2014. The measurement temperature of the melt mass flow rate is 230°C.

[0044] The covering 70 has a first surface 70X and a second surface 70Y. The first surface 70X faces the electrode body 20. An opening 70Z is formed substantially entirely in the first surface 70X. The second surface 70Y is the surface on the side opposite to the first surface 70X. An opening 70YA into which a lid body 80 described later is fitted is formed in the second surface 70Y. The opening 70YA penetrates the second surface 70Y. The shape of the opening 70YA in a front view can be arbitrarily selected according to the shape of the lid body 80. The shape of the opening 70YA may be a square, a rectangle, a polygon with three or more sides, a circle, or an ellipse. In the present embodiment, the shape of the opening 70YA in a front view is a rectangle. The corners of the opening 70YA are preferably rounded by R processing. When the covering 70 is configured to include a resin material, from the viewpoint of preferably joining the lid body 80, an adhesive film that can be joined to a metal material and a resin material is preferably joined to at least a part of the inner peripheral surface of the opening 70YA. In another example, when the covering 70 is configured to include a resin material, from the viewpoint of preferably joining the lid body 80, at least a part of the portion corresponding to the inner peripheral surface of the opening 70YA of the covering 70 preferably has a layer that can be joined to a metal material.

[0045] The covering body 70 includes an upper portion 71, side portions 72, 73, a lower portion 74, and a protruding portion 70A. The upper portion 71 constitutes the upper surface of the lid body 60. The upper portion 71 extends in a first direction (in this embodiment, the LR direction) in a front view of the lid body 60. The side portions 72 and 73 are connected to the upper portion 71 and constitute the side surfaces of the lid body 60. The side portions 72 and 73 extend in a second direction (in this embodiment, the UD direction) that intersects the first direction in a front view of the lid body 60. In this embodiment, in a front view of the lid body 60, the first direction and the second direction are orthogonal. The first direction and the second direction do not have to be orthogonal in a front view of the lid body 60. The lower portion 74 constitutes the lower surface of the lid body 60. The lower portion 74 extends in a first direction (in this embodiment, the LR direction) in a front view of the lid body 60.

[0046] The protruding portion 70A protrudes inward of the covering body 70 from the upper portion 71, the side portions 72, 73, and the lower portion 74. The protruding portion 70A covers the lid main body 80, in other words, defines the opening 70YA. The protruding amount of the protruding portion 70A from the upper portion 71, the side portions 72, 73, and the lower portion 74 can be arbitrarily selected. The larger the protruding amount of the protruding portion 70A from the upper portion 71, the side portions 72, 73, and the lower portion 74, the smaller the opening area of the opening 70YA. In other words, the smaller the protruding amount of the protruding portion 70A from the upper portion 71, the side portions 72, 73, and the lower portion 74, the larger the opening area of the opening 70YA. In the covering body 70, the protruding portion 70A may be omitted.

[0047] The covering body 70 further includes boundaries 75, 76, 77, 78. The boundary 75 is the boundary between the upper portion 71 and the side portion 72. The boundary 76 is the boundary between the upper portion 71 and the side portion 73. The boundary 77 is the boundary between the lower portion 74 and the side portion 72. The boundary 78 is the boundary between the lower portion 74 and the side portion 73. The shapes of the boundaries 75 to 78 may be corners, or may be rounded by R processing. In this embodiment, the boundaries 75 to 78 are corners.

[0048] The lid body 80 shown in FIG. 5 is composed of a metal material. The definition of "composed of a metal material" and the specifications of the metal material constituting the lid body 80 are the same as those of the covering body 70. The lid body 80 may be composed of a resin material. The definition of "composed of a resin material" and the specifications of the resin material constituting the lid body 80 are the same as those of the covering body 70. At least one of the covering body 70 and the lid body 80 is composed of a metal material. In this embodiment, the covering body 70 and the lid body 80 are composed of a metal material. The lid body 80 has a first surface 81, a second surface 82, and a covering portion 83. The first surface 81 faces the electrode body 20. The first surface 81 is joined to the end of the current collector (not shown) of the electrode body 20 by, for example, welding. The second surface 82 is the surface on the opposite side of the first surface 81. An electrode terminal may be connected to the second surface 82. When the lid body 80 is composed of a metal material, it is preferable that the lid body 80 has the corrosion-resistant film described in the barrier layer 52.

[0049] The covering portion 83 is connected to the first surface 81 and the second surface 82, and at least a part of it is covered by the covering body 70. In this embodiment, when the lid body 80 is fitted into the opening 70YA of the covering body 70, the entire covering portion 83 is covered by the inner peripheral surface of the opening 70YA. In a state where the lid body 80 is fitted into the opening 70YA of the covering body 70, a part of the covering portion 83 may be exposed from the covering body 70. The lid body 80 may be fitted into the opening 70Z.

[0050] The covering portion 83 includes a first covering portion 83A, a second covering portion 83B, a third covering portion 83C, and a fourth covering portion 83D. The first covering portion 83A constitutes the upper surface of the lid body 80. The first covering portion 83A extends in a first direction (in this embodiment, the LR direction) when viewed from the front of the lid body 80. The second covering portion 83B and the third covering portion 83C are connected to the first covering portion 83A and constitute the side surface of the lid body 80. The second covering portion 83B and the third covering portion 83C extend in a second direction (in this embodiment, the UD direction) that intersects the first direction when viewed from the front of the lid body 80. In this embodiment, the first direction and the second direction are orthogonal when viewed from the front of the lid body 80. The first direction and the second direction do not have to be orthogonal when viewed from the front of the lid body 80. The fourth covering portion 83D constitutes the lower surface of the lid body 80. The fourth covering portion 83D extends in the first direction (in this embodiment, the LR direction) when viewed from the front of the lid body 80.

[0051] The covering portion 83 further includes boundaries 84, 85, 86, and 87. The boundary 84 is the boundary between the first covering portion 83A and the second covering portion 83B. The boundary 85 is the boundary between the first covering portion 83A and the third covering portion 83C. The boundary 86 is the boundary between the fourth covering portion 83D and the second covering portion 83B. The boundary 87 is the boundary between the fourth covering portion 83D and the third covering portion 83C. The shapes of the boundaries 84 to 88 may be corners or may be rounded by R processing. In this embodiment, the boundaries 84 to 87 are corners.

[0052] When the lid body 60 is plate-shaped as a whole, even when the power storage devices 10 are stacked, it is preferable that the lid body 60 has a certain thickness so that the exterior body 40 is prevented from deforming. The minimum value of the thickness of the covering body 70 in the FB direction 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 covering body 70 of the lid body 60 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum value of the thickness of the covering body 70 of the lid body 60 may be 20 mm or more. The preferable range of the thickness of the covering body 70 of the lid body 60 is 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, 4.0 mm to 10 mm. Note that the thickness of the covering body 70 of the lid body 60 may vary depending on the part of the lid body 60. When the thickness of the covering body 70 of the lid body 60 varies depending on the part, the thickness of the covering body 70 of the lid body 60 is the thickness of the thickest part.

[0053] In the present embodiment, the first sealing portion 91 is formed by heat-sealing the mutually facing surfaces (heat-sealable resin layers 53) of the exterior film 50.

[0054] The first sealing portion 91 is configured to include a portion where the first edge 50A and the second edge 50B of the exterior film 50 shown in FIG. 3 are overlapped. The first sealing portion 91 extends in the longitudinal direction (FB direction) of the exterior body 40. In the exterior body 40, the position where the first sealing portion 91 is formed can be arbitrarily selected. In the present embodiment, it is preferable that the base 91X of the first sealing portion 91 is located on the side 43 at the boundary between the first surface 41A and the second surface 42A of the exterior body 40. The base 91X of the first sealing portion 91 may be located on any surface of the exterior body 40. From the viewpoint of making the power storage device 10 compact, when the power storage device 10 is in use, the first sealing portion 91 is preferably folded onto, for example, the first surface 41A or the second surface 42A of the exterior body 40.

[0055] In the present embodiment, a second sealing portion 92 (see FIGS. 6 and 7) is formed by sandwiching a portion including an end portion of the exterior film 50 in the FB direction between the inner peripheral surface of the opening 70YA of the covering body 70 and the covering portion 83.

[0056] As shown in FIG. 7, in the second sealing portion 92, the barrier layer 52 of the exterior film 50 and a portion of the lid body 60 including a metal material are directly joined. In the present embodiment, "directly joined" means that the barrier layer 52 of the exterior film 50 and a portion of the lid body 60 including a metal material are joined without passing through other elements. In the present embodiment, the covering body 70 and the lid main body 80 are configured to include a metal material. Therefore, in the second sealing portion 92, the barrier layer 52 of the exterior film 50 is directly joined to the covering body 70 and the lid main body 80. The barrier layer 52 of the exterior film 50 and the covering body 70 and the lid main body 80 are joined by, for example, metal welding. Metal welding is, for example, arc welding, TIG welding, spot welding, brazing, gas welding, or laser welding, etc. The barrier layer 52 of the exterior film 50 and the covering body 70 and the lid main body 80 may be joined by, for example, ultrasonic welding. Also, the barrier layer 52 of the exterior film 50 and the upper portion 71, side portions 72, 73, and lower portion 74 of the covering body 70 may be directly joined. In this case, the covering body 70 and the lid main body 80 may be joined by metal welding, caulking, or using an adhesive. Note that in FIG. 7, for simplicity of the drawing, the illustration of the adhesive layers 54 and 55 is omitted.

[0057] In the example shown in FIG. 7, the portion of the exterior film 50 that constitutes the second sealing portion 92, in other words, the portion of the exterior film 50 that is joined to the covering body 70 and the lid main body 80, does not have the base material layer 51 and the heat-fusible resin layer 53 laminated on the barrier layer 52. That is, the portion of the exterior film 50 that constitutes the second sealing portion 92 is a single layer of the barrier layer 52.

[0058] <1-2. Method for manufacturing a power storage device> FIG. 8 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, and a sixth step. The first to sixth steps are, for example, performed by a manufacturing apparatus for the power storage device 10. At least a part of the first to sixth steps may be performed by an operator. Note that the first to sixth steps are defined for convenience as the names of the respective steps of the method for manufacturing the power storage device 10, and do not necessarily mean the order of the respective steps. The order of the following steps can be arbitrarily changed.

[0059] In the first step of step S1, the manufacturing apparatus arranges a pair of lid bodies 80 on the sides of the electrode body 20 and electrically connects the electrode body 20 and the lid bodies 80.

[0060] The second step of step S2 is performed after the first step. In the second step, the manufacturing apparatus wraps the electrode body 20 and the pair of lid bodies 80 with the exterior film 50.

[0061] The third step of step S3 is performed after the second step. In the third step, an end seal portion is formed. The end seal portion is a portion where a predetermined range including both end portions in the LR direction is joined at a portion where the first sealing portion 91 of the exterior film 50 is to be formed. The end seal portion is folded toward the first surface 41A or the second surface 42A.

[0062] The fourth step of step S4 is performed after the third step. In the fourth step, the manufacturing apparatus fits the lid body 80 into the opening 70YA of the covering body 70. By completing the fourth step, a portion including the end portion of the exterior film 50 in the FB direction and the end seal portion are sandwiched between the inner peripheral surface of the opening 70YA of the covering body 70 and the covering portion 83 of the lid body 80.

[0063] The fifth step of step S5 is carried out after the fourth step. In the fifth step, the manufacturing apparatus forms the second sealing portion 92 by welding the covering body 70, the lid body 80, and the exterior film 50. Since the joining of the covering body 70, the lid body 80, and the exterior film 50 can be completed in one step, the power storage device 10 can be easily manufactured.

[0064] The sixth step of step S6 is carried out before or after the fifth step. In the sixth step, the manufacturing apparatus forms the first sealing portion 91 by heat-sealing the heat-sealable resin layer 53 of the portion including the first edge 50A of the exterior film 50 and the heat-sealable resin layer 53 of the portion including the second edge 50B.

[0065] <1-3. Operation and Effects of the Power Storage Device> Since the barrier layer 52 of the exterior film 50 and the portion of the lid body 60 including the metal material are directly joined by welding in the power storage device 10, the intrusion of moisture into the interior of the exterior body 40 from the second sealing portion 92 is suppressed. For this reason, the power storage device 10 has high moisture barrier properties.

[0066] [2. Modification Example] The above-described embodiment is an exemplification of a form that the power storage device, the exterior film, and the manufacturing method of the power storage device according to the present invention can take, and is not intended to limit the form. The power storage device, the exterior film, and the manufacturing method of the power storage device according to the present invention can take forms different from the forms exemplified in the embodiment. One example is a form in which a part of the configuration of the embodiment is replaced, changed, or omitted, or a new configuration is added to the embodiment. Some examples of modification examples of the embodiment are shown below. Note that the following modification examples can be combined with each other as long as there is no technical contradiction.

[0067] <2-1. First Modification Example> In the above-described embodiment, the covering 70 may be configured to include a resin material, and the lid body 80 may be configured to include a metal material. FIG. 9 is a cross-sectional view of the power storage device 10 according to the first modification. In the first modification, it is preferable that the innermost layer and the outermost layer of the exterior film 50 are heat-fusible resin layers 53A and 53B. In the portion of the exterior film 50 that is directly joined to the lid body 80 in the second sealing portion 92, it is preferable that the heat-fusible resin layer 53A, which is the innermost layer, is partially removed. In the example shown in FIG. 9, in the portion of the exterior film 50 that is directly joined to the lid body 80 in the second sealing portion 92, the heat-fusible resin layer 53A, which is the innermost layer, is partially removed, and the barrier layer 52 is exposed. In the second sealing portion 92, the barrier layer 52 of the exterior film 50 and the lid body 80 are joined by welding. In the second sealing portion 92, the heat-fusible resin layer 53B, which is the outermost layer of the exterior film 50, and the covering 70 may be joined by, for example, heat sealing. The first sealing portion 91 is preferably formed by heat-sealing the heat-fusible resin layer 53A and the heat-fusible resin layer 53B. In the fourth step, since it is not necessary to sandwich the end seal portion between the inner peripheral surface of the opening 70YA of the covering 70 and the covering portion 83 of the lid body 80, the power storage device 10 can be easily manufactured.

[0068] <2-2. Second Modification> In the above-described embodiment, the covering 70 may be configured to include a metal material, and the lid body 80 may be configured to include a resin material. FIG. 10 is a cross-sectional view of the power storage device 10 according to the second modification. In the second modification, it is preferable that the innermost layer and the outermost layer of the exterior film 50 are heat-fusible resin layers 53A and 53B. In the portion of the exterior film 50 that is directly joined to the covering 70 in the second sealing portion 92, the heat-fusible resin layer 53B, which is the outermost layer, is partially removed, and the barrier layer 52 is exposed. In the second sealing portion 92, the barrier layer 52 of the exterior film 50 and the covering 70 are joined by welding. In the second sealing portion 92, the heat-fusible resin layer 53A, which is the innermost layer of the exterior film 50, and the lid body 80 may be joined by, for example, heat sealing.

[0069] <2-3. Third Modification Example> In the above embodiment, the lid body 60 may not have the covering body 70. FIG. 11 is a cross-sectional view of the power storage device 10 according to the third modification example. In the third modification example, the lid main body 80 is configured to include a metal material. In the second sealing portion 92 of the exterior film 50, the portion directly joined to the lid main body 80 may have the heat-sealable resin layer 53 partially removed and the barrier layer 52 exposed.

[0070] FIG. 12 is a cross-sectional view of the power storage device 10 according to another example of the third modification example. In the second sealing portion 92 of the exterior film 50, the portion directly joined to the lid main body 80 may be a single layer of the barrier layer 52 with the base material layer 51 and the heat-sealable resin layer 53 removed.

[0071] <2-4. Fourth Modification Example> In the above embodiment, the configuration of the exterior film 50 can be changed. FIG. 13 is a cross-sectional view showing an example of the layer configuration of the exterior film 50X provided in the power storage device 10 according to the fourth modification example.

[0072] The exterior film 50X is a laminated film including a first barrier layer 510, a second barrier layer 520, and an insulating layer 530. The first barrier layer 510, the second barrier layer 520, and the insulating layer 530 are laminated so that the first barrier layer 510 and the second barrier layer 520 are not electrically connected. In the fourth modification example, from the outside of the exterior body 40 toward the electrode body 20, the first barrier layer 510, the insulating layer 530, and the second barrier layer 520 are laminated in this order. The first barrier layer 510 and the second barrier layer 520 are configured to include a metal material.

[0073] The first barrier layer 510 is joined to the lid body 60 connected to the positive electrode. From the viewpoint of increasing the joining strength between the first barrier layer 510 and the lid body 60 connected to the positive electrode, the metal material included in the material constituting the first barrier layer 510 is preferably the same metal material as the metal material included in the material constituting the lid body 60 connected to the positive electrode. The second sealing portion 92 is configured to include the end portion of the first barrier layer 510.

[0074] The second barrier layer 520 is joined to the lid 60 connected to the negative electrode. From the viewpoint of increasing the joining strength between the second barrier layer 520 and the lid 60 connected to the negative electrode, the metal material contained in the material constituting the second barrier layer 520 is preferably the same metal material as the metal material contained in the material constituting the lid 60 connected to the negative electrode. The second sealing portion 92 is configured to include an end portion of the second barrier layer 520.

[0075] The insulating layer 530 insulates the first barrier layer 510 and the second barrier layer 520 so that the first barrier layer 510 and the second barrier layer 520 do not conduct. The material constituting the insulating layer 530 can be arbitrarily selected as long as it can insulate the first barrier layer 510 and the second barrier layer 520. The material constituting the insulating layer 530 is, for example, a resin, an elastomer, or a ceramic. The ceramic is, for example, glass, an oxide, a nitride, a carbonate, or a hydroxide. The material constituting the insulating layer 530 may be a combination of a plurality of materials. From the viewpoint of preferably insulating the first barrier layer 510 and the second barrier layer 520, the material constituting the insulating layer 530 preferably contains an insulating filler.

[0076] The resin is, for example, a thermoplastic resin such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, phenol resin, etc., fluororesin, and modified products of these resins. From the viewpoint of moisture barrier properties, it is preferable to use a fluororesin and a thermoplastic resin such as a modified product of a fluororesin.

[0077] The ceramic is, for example, an oxide or a nitride. The oxide is, for example, magnesium oxide, silicon oxide, aluminum oxide, or tin oxide. These oxides have moisture barrier properties.

[0078] The nitride is, for example, aluminum nitride, boron nitride, or silicon nitride. From the viewpoint of moisture barrier properties, it is preferable to use silicon nitride.

[0079] The carbonate is, for example, magnesium carbonate. The hydroxide is, for example, magnesium hydroxide. Magnesium carbonate and magnesium hydroxide have moisture barrier properties.

[0080] In plan view, the exterior film 50 preferably includes an overlapping portion 500X where the first barrier layer 510, the insulating layer 530, and the second barrier layer 520 overlap. When the exterior film 50 includes the overlapping portion 500X, even if the material constituting the insulating layer 530 does not have moisture barrier properties, the moisture barrier properties are enhanced by the first barrier layer 510 and the second barrier layer 520. In the fourth modification, the overlapping portion 500X is formed so as to cover substantially the entire upper and lower surfaces of the electrode body 20.

[0081] In the FB direction, the first barrier layer 510 extends to the side of the lid body 60 connected to the positive electrode further than the second barrier layer 520 and the insulating layer 530.

[0082] In the FB direction, the second barrier layer 520 extends to the side of the lid body 60 connected to the negative electrode further than the first barrier layer 510 and the insulating layer 530. From the viewpoint of suppressing a short circuit between the second barrier layer 520 and the electrode body 20, it is preferable that another insulating layer is laminated on the surface of the second barrier layer 520 opposite to the surface on which the insulating layer 530 is laminated.

[0083] From the viewpoint of suitably suppressing conduction between the first barrier layer 510 and the second barrier layer 520, in the FB direction, the end portion 530X on the side of the lid body 60 connected to the positive electrode of the insulating layer 530 is preferably located closer to the lid body 60 connected to the positive electrode than the end portion 520X on the side of the lid body 60 connected to the positive electrode of the second barrier layer 520.

[0084] From the viewpoint of suitably suppressing conduction between the first barrier layer 510 and the second barrier layer 520, in the FB direction, the end portion 530Y on the side of the lid body 60 connected to the negative electrode of the insulating layer 530 is preferably located closer to the lid body 60Y connected to the negative electrode than the end portion 510Y on the side of the lid body 60 connected to the negative electrode of the first barrier layer 510.

[0085] In the first modification example, since the first barrier layer 510 and the second barrier layer 520 are insulated by the insulating layer 530, the lid 60 connected to the positive electrode and the lid 60 connected to the negative electrode do not conduct.

[0086] <2-5. Fifth Modification Example> In the above embodiment, the exterior film 50 of the power storage device 10 may protrude outside one of the two lids 60 in the FB direction. By closing the portion of the exterior film 50 that protrudes outside the lid 60, the electrode body 20 is sealed. The portion of the exterior film 50 that protrudes outside the lid 60 may be folded inward so that the outer surfaces of the exterior film 50 contact each other, like a gable-top container, or may be folded toward any surface of the exterior body 40, like a brick-shaped container.

[0087] <2-6. Sixth Modification Example> In the above embodiment, the exterior body 40 may not have one of the two lids 60. In this modification example, in the FB direction, in the portion where the lid 60 of the exterior body 40 is omitted, by closing the portion of the exterior film 50 that protrudes outside the electrode body 20, the electrode body 20 is sealed. The portion of the exterior film 50 that protrudes outside the electrode body 20 may be folded in the same manner as in the fifth modification example, like a gable-top container or a brick-shaped container.

[0088] <2-7. Seventh Modification Example> In the above embodiment, the outer shape of the exterior body 40 can be arbitrarily changed. The outer shape of the exterior body 40 may be a cylinder, a prism, or a cube.

[0089] <2-8. Eighth Modification Example> In the above embodiment, the electrode body 20 is wrapped by one exterior film 50, but may be wrapped by two or more exterior films 50.

Description of Reference Numerals

[0090] 10: Energy storage device 20: Electrode body 40: Outer package 50: Outer film 53: Barrier layer 60: Cover 70, 470: Coating 80: Cover body 92: Second sealing part (sealing part)

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; a lid that seals the electrode body together with the exterior film, The exterior film includes a barrier layer including a metal material, The lid body includes a portion including a metal material, The barrier layer of the exterior film and a portion of the lid body that contains a metal material are directly bonded to each other. Energy storage device.

2. The portion of the exterior film that is bonded to the portion of the lid that is configured to include a metal material is a single layer of the barrier layer. The power storage device according to claim 1 .

3. The exterior film includes another layer laminated to the barrier layer, The portion of the exterior film that is bonded to the portion of the lid that is configured to contain a metal material is a portion where the barrier layer is partially exposed from the other layer. The power storage device according to claim 1 .

4. The lid body is A covering body; A lid body joined to the cover body, At least one of the cover and the lid body is configured to include a metal material, the exterior body has a sealing portion in which the exterior film is sandwiched between the cover body and the lid main body, The barrier layer of the exterior film is directly bonded to the covering body and the portion of the lid body that contains a metal material at the sealing portion. The electricity storage device according to any one of claims 1 to 3.

5. An exterior film used as an exterior body of an electricity storage device, The exterior body has a lid body containing a metal material, The exterior film is A barrier layer comprising a metallic material; The portion of the lid body that is to be joined to the portion containing the metal material is a single layer of the barrier layer, or the barrier layer is partially exposed from another layer. Exterior film.

6. A method for manufacturing an electricity storage device, comprising: The power storage device is An electrode body; and an exterior body that seals the electrode body, The exterior body is An exterior film that wraps the electrode body; a lid that seals the electrode body together with the exterior film, The exterior film includes a barrier layer including a metal material, The lid body includes a portion including a metal material, The method for manufacturing the electricity storage device includes: The barrier layer of the exterior film and a portion of the lid body that contains a metal material are directly bonded to each other. A method for manufacturing an electricity storage device.

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