Power storage device, lid body, coating body, and method for manufacturing power storage device

Abstract

To provide a power storage device that can be manufactured by various different procedures, a lid body used for the power storage device, a coating body forming the lid body, and a method for manufacturing the power storage device.SOLUTION: The power storage device includes an electrode body and an external body for sealing the electrode body. The external body has an external film surrounding the electrode body and a lid body for sealing the electrode body with the external film. The lid body includes: a lid body including metal material; and a coating body joined to the external film and covering at least a part of the edge of the lid body.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a power storage device, a lid body, a covering body, and a method for manufacturing a power storage device.

Background Art

[0002] Patent Document 1 discloses an example of a power storage device. This power storage device includes an electrode body 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.

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, after the electrode body and the lid body are connected, the electrode body and the lid body are wrapped by an exterior film. Since the electrode body is sealed at the stage where the electrode body and the lid body are wrapped by the exterior film, the procedure of the manufacturing method process is limited.

[0005] An object of the present invention is to provide a power storage device that can be manufactured by various procedures, a lid body used for this power storage device, a covering body constituting this lid body, 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 lid body has a lid main body formed of a metal material and a covering body joined to the exterior film and covering at least a part of the lid main body.

[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 the covering body has a main body portion formed of a metal material.

[0008] The power storage device according to the third aspect of the present invention is the power storage device according to the second aspect, and the volume of the main body portion is smaller than the volume of the lid main body.

[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, and the covering body has a lid seal portion joined to the exterior film and a protruding portion protruding from the lid seal portion and defining a portion covering the edge of the lid main body.

[0010] The power storage device according to the fifth aspect of the present invention is the power storage device according to the second or third aspect, and the covering body further has a joining portion covering at least a part of the edge of the main body portion.

[0011] The power storage device according to the sixth aspect of the present invention is the power storage device according to the fifth aspect, and the joining portion is a resin molded product.

[0012] The power storage device according to the seventh aspect of the present invention is the power storage device according to the fifth aspect, and the joining portion is an adhesive film capable of being joined to a metal material and a resin material.

[0013] The power storage device according to the eighth aspect of the present invention is the power storage device according to the fifth aspect, and the joining portion is an adhesive.

[0014] The lid body according to the ninth aspect of the present invention is a lid body used as an exterior body of a power storage device, and includes a lid main body formed of a metal material, and a covering body joined to an exterior film constituting the exterior body and covering at least a part of an edge of the lid main body.

[0015] The covering body according to the tenth aspect of the present invention is a covering body constituting a lid body used as an exterior body of a power storage device, the lid body has a lid main body formed of a metal material, the covering body is joined to an exterior film constituting the exterior body, and is configured to cover at least a part of an edge of the lid main body.

[0016] The manufacturing method of a power storage device according to the eleventh 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 lid body includes a lid main body formed of a metal material, and a covering body joined to the exterior film and covering at least a part of the lid main body. The manufacturing method of the power storage device includes a film joining step of joining the exterior film and the covering body, and a closing step of joining the covering body and the lid main body, which is performed after the film joining step.

Advantages of the Invention

[0017] According to the power storage device, lid body, covering body, and manufacturing method of a power storage device of the present invention, the power storage device can be manufactured by various procedures.

Brief Description of the Drawings

[0018]

Fig. 1A

Fig. 1B

Fig. 2

Fig. 3

Fig. 4A

Fig. 4B

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Fig. 9

Mode for Carrying Out the Invention

[0019] 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 2~15 mm means 2 mm or more and 15 mm or less.

[0020] [1. Embodiment] <1-1. Configuration of Power Storage Device> FIG. 1A is a perspective view schematically showing the power storage device 10 of the embodiment. FIG. 1B is a diagram regarding a method for measuring the seal strength of the second sealing portion 92 of the power storage device 10 of FIG. 1. FIG. 2 is a cross-sectional view showing an example of the layer configuration of the exterior film 50 included in the power storage device 10 of FIG. 1A. FIG. 3 is a view of the exterior film 50 included in the power storage device 10 of FIG. 1A in a spread state. FIG. 4A is a perspective view of the main body portion 70A of the covering body 70 included in the power storage device of FIG. 1A. FIG. 4B is a cross-sectional view taken along 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. 1A. FIG. 6 is a front view of the power storage device 10 of FIG. 1A. FIG. 7 is a cross-sectional view taken along line D7-D7 of FIG. 1. In FIG. 1A, the direction of arrow UD indicates the thickness direction of the power storage device 10, the direction of arrow LR indicates the width direction of the power storage device 10, and the direction of arrow FB indicates the depth direction of the power storage device 10. The directions indicated by each of the arrows UDLRFB are common in each of the subsequent figures.

[0021] The power storage device 10 includes an electrode body 20 including a current collector 30 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, and a separator and the like. In the present embodiment, the shape of the electrode body 20 is a substantially 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.

[0022] 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 such that a pair of openings 40A are formed. In the present embodiment, the exterior film 50 is wound around the electrode body 20 such that a pair of openings 40A are formed. Note that the electrode body 20 may be housed inside the exterior film 50 configured in a tubular shape such that a pair of openings 40A are formed, and the openings 40A may be closed by the lid body 60. The exterior body 40 has a pair of first surfaces 41A, 41B and a pair of second surfaces 42A, 42B. In the present embodiment, the pair of first surfaces 41A, 41B are substantially the same size. In the present embodiment, the pair of second surfaces 42A, 42B are substantially the same size. The pair of first surfaces 41A, 41B are larger in area than the pair of second surfaces 42A, 42B. The pair of lid bodies 60 are respectively disposed on the sides of the electrode body 20 so as to close the pair of openings 40A.

[0023] For example, there is a method of forming a depression in the exterior film 50 through cold forming to house the electrode body 20. However, it is not always easy to form a deep depression by such a method. If an attempt is made to form a deep depression (for example, a forming depth of 15 mm) by cold forming, pinholes or cracks are likely to occur in the exterior film 50, leading to a high 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 order to reduce the dead space between the electrode body 20 and the exterior film 50 to improve the volume 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 outside 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.

[0024] As shown in FIG. 2, the exterior film 50 is a laminate (laminated film) having, for example, a base material layer 51, a barrier layer 52, and a heat-sealable resin layer 53 in this order. Note that all of these layers do not necessarily need to be included in the exterior film 50, and for example, the barrier layer 52 may not be included. That is, the exterior film 50 may be made of a material that has flexibility and is 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.

[0025] The overall thickness of the exterior film 50 can be arbitrarily selected. From the viewpoint of strength, the thickness of the exterior film 50 is preferably 50 μm or more.

[0026] 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 generation 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 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. Further, from the viewpoint 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. The thickness of the base material layer 51 is preferably, for example, 5 to 300 μm, and more preferably 5 to 150 μm, from the viewpoint of film strength.

[0027] 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, and a resin layer. Examples of the vapor deposition film include a metal vapor deposition film, an inorganic oxide vapor deposition film, and a carbon-containing inorganic oxide vapor deposition film. 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 a fluoroalkyl group, and polymers mainly composed of fluoroalkyl units, and ethylene-vinyl alcohol copolymers. Also, 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. The barrier layer 52 preferably 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, and steel plates. When used as a metal foil, it preferably includes at least one of an aluminum alloy foil and a stainless steel foil.

[0028] 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 a virgin material. Note that the recycled material of the metal material refers to a metal material that has been recovered, isolated, purified, etc. from various products used in the market, waste from the manufacturing process, etc. and made reusable. Also, 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.

[0029] 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 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 strain-hardened aluminum alloy. Examples of the hard aluminum alloy foil include aluminum alloy foils having a composition defined by 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 a composition defined by JIS H4000:2017 A5005P-O, JIS H4000:2017 A5050P-O, or JISH4000:2017 A5052P-O.

[0030] 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 with excellent formability, the stainless steel foil is preferably composed of austenitic stainless steel.

[0031] Specific examples of the austenitic stainless steel constituting the stainless steel foil include SUS304, SUS301, SUS316L, etc. Among these, SUS304 is particularly preferable.

[0032] 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 intrusion of moisture, and for example, it can be about 9 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. Further, 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 composed of an aluminum alloy foil, the above-mentioned 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 the high sealing performance of the power storage device.Further, particularly when the barrier layer 52 is composed 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, preferable ranges of the thickness of the stainless steel foil include about 10 to 60 μm, about 10 to 50 μm, about 10 to 40 μm, about 10 to 30 μm, about 10 to 25 μm, about 15 to 60 μm, about 15 to 50 μm, about 15 to 40 μm, about 15 to 30 μm, and about 15 to 25 μm.

[0033] Also, 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 means, for example, a thin film that is formed by performing a hydrothermal transformation treatment such as a boehmite treatment, a chemical conversion treatment, an anodic oxidation 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 and alkali resistance). 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. Further, among these treatments, the hydrothermal transformation treatment and the anodic oxidation treatment are treatments that dissolve the metal foil surface with a treatment agent and form a metal compound excellent in 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 regarded as the barrier layer 52.

[0034] 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 electrolytes and moisture. In particular, when the barrier layer 52 is an aluminum alloy foil, it prevents dissolution and corrosion of aluminum oxide present on the surface of the barrier layer 52. 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.

[0035] 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 sealing properties by heat sealing to the outer packaging film 50. Examples of the heat-sealable resin layer 53 include 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 resin films made of 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.

[0036] 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.

[0037] 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, still 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.

[0038] 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, still 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.

[0039] 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 the handling during the manufacture of the power storage device 10.

[0040] The lid body 60 has a covering body 70 and a lid main body 80.

[0041] The covering body 70 has a main body portion 70A and a joint portion 70B. The main body portion 70A has a shape similar to, for example, a hollow rectangular parallelepiped. A space 79 is formed inside the main body portion 70A. The material constituting the main body portion 70A can be arbitrarily selected. From the viewpoint of easily joining with the lid body 80, the main body portion 70A is preferably composed of a metal material. Here, "composed of a metal material" means that when the total amount of the material constituting the main body portion 70A 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 main body portion 70A can contain a material other than the metal material in addition to the metal material. The metal material constituting the main body portion 70A can be arbitrarily selected. The metal material constituting the main body portion 70A 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 main body portion 70A connected to the positive electrode is preferably composed of aluminum or an aluminum alloy. The main body portion 70A connected to the negative electrode is preferably composed of nickel, copper, or a copper alloy. The material constituting the main body portion 70A connected to the negative electrode may be nickel-plated copper. The material constituting the main body portion 70A may contain a recycled material of the metal material. In the present embodiment, the main body portion 70A is composed of only the metal material. Since the main body portion 70A 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.

[0042] When the main body portion 70A is composed of a metal material, the main body portion 70A preferably has a corrosion-resistant film as described for the barrier layer 52.

[0043] In another example, the main body 70A may be configured to include a resin material. Here, "configured to include a resin material" means that when the total amount of the materials constituting the main body 70A 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 even more preferably 95% by mass or more. That is, the materials constituting the main body 70A can contain materials other than the resin material in addition to the resin material.

[0044] Specific examples of the resin include resins such as polyester, polyolefin, polyamide, epoxy resin, acrylic resin, fluororesin, polyurethane, silicone resin, and phenolic 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 main body 70A may be formed by any molding method.

[0045] 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, even more preferably contains polyolefin as a main component, and even 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.

[0046] 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 polymers obtained by polymerizing ethylene isophthalate with ethylene terephthalate as the main repeating unit (hereinafter abbreviated following polyethylene(terephthalate / isophthalate)), 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.

[0047] 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, polypropylene is preferable because the resin material is excellent in heat sealability and electrolyte resistance.

[0048] The resin as the resin material may contain a filler as required. Specific examples of the filler include glass beads, graphite, glass fibers, carbon fibers, and the like. By the resin as the resin material containing the filler, the deformation resistance of the joint portion 70B against temperature changes can be improved.

[0049] The melt mass flow rate of the resin material contained in the material constituting the main body portion 70A 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.

[0050] The main body portion 70A has a first surface 70X and a second surface 70Y. The first surface 70X faces the electrode body 20. An opening 70Z is formed generally over the entire first surface 70X. The second surface 70Y is the surface on the side opposite to the first surface 70X. An opening 70YA into which the lid body 80 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 main body portion 70A is configured to include a resin material, from the viewpoint of suitably joining the lid body 80, an adhesive film capable of joining 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 main body portion 70A is configured to include a resin material, from the viewpoint of suitably joining the lid body 80, at least a part of the portion corresponding to the inner peripheral surface of the opening 70YA in the main body portion 70A preferably has a layer capable of joining to a metal material.

[0051] The main body portion 70A has a lid seal portion 71 and a protruding portion 77. The lid seal portion 71 is heat-sealed via a joint portion 70B to the heat-fusible resin layer 53 of the exterior film 50. The lid seal portion 71 includes a first seal surface 71A, a second seal surface 71B, a third seal surface 71C, and a fourth seal surface 71D. The first seal surface 71A constitutes the upper surface of the lid body 60. The first seal surface 71A extends in a first direction (in this embodiment, the LR direction) when viewed from the front of the lid body 60. The second seal surface 71B and the third seal surface 71C are connected to the first seal surface 71A and constitute the side surfaces of the lid body 60. The second seal surface 71B and the third seal surface 71C 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 60. In this embodiment, the first direction and the second direction are orthogonal when viewed from the front of the lid body 60. The first direction and the second direction do not have to be orthogonal when viewed from the front of the lid body 60. The fourth seal surface 71D constitutes the lower surface of the lid body 60. The fourth seal surface 71D extends in a first direction (in this embodiment, the LR direction) when viewed from the front of the lid body 60.

[0052] The protruding portion 77 protrudes inward from the lid seal portion 71 of the main body portion 70A. The protruding portion 77 covers the lid main body 80, in other words, defines the opening portion 70YA. The protruding amount of the protruding portion 77 from the lid seal portion 71 can be arbitrarily selected. The larger the protruding amount of the protruding portion 77 from the lid seal portion 71, the smaller the opening area of the opening portion 70YA. In other words, the smaller the protruding amount of the protruding portion 77 from the lid seal portion 71, the larger the opening area of the opening portion 70YA. In the main body portion 70A, the protruding portion 77 may be omitted.

[0053] The lid seal portion 71 further includes boundaries 72, 73, 74, 75. The boundary 72 is the boundary between the first seal surface 71A and the second seal surface 71B. The boundary 73 is the boundary between the first seal surface 71A and the third seal surface 71C. The boundary 74 is the boundary between the fourth seal surface 71D and the second seal surface 71B. The boundary 75 is the boundary between the fourth seal surface 71D and the third seal surface 71C. The shapes of the boundaries 72 to 75 may be corners, or may be rounded by R processing. In this embodiment, the boundaries 72 to 75 are corners.

[0054] 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 suppressed from deforming. From another perspective, when the lid body 60 is plate-shaped, when forming the second sealing portion 92 described later, it is preferable that the lid seal portion 71 of the lid body 60 has a certain thickness so that the lid seal portion 71 of the lid body 60 and the exterior film 50 can be suitably heat-sealed. The minimum value of the thickness of the lid seal portion 71 of the lid body 60 is, for example, 1.0 mm, more preferably 3.0 mm, and even more preferably 4.0 mm. The maximum value of the thickness of the lid seal portion 71 of the lid body 60 is, for example, 20 mm, more preferably 15 mm, and even more preferably 10 mm. The maximum value of the thickness of the lid seal portion 71 of the lid body 60 may be 20 mm or more. The preferable range of the thickness of the lid seal portion 71 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 lid seal portion 71 of the lid body 60 may vary depending on the part of the lid body 60. When the thickness of the lid seal portion 71 of the lid body 60 varies depending on the part, the thickness of the lid seal portion 71 of the lid body 60 is the thickness of the thickest part.

[0055] The lid body 80 shown in FIG. 5 is configured to include a metal material. The definition of "configured to include a metal material" and the specifications regarding the metal material constituting the lid body 80 are the same as those of the covering body 70. 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 portion 31 of the current collector 30 of the electrode body 20 by, for example, welding or the like. The second surface 82 is the surface on the side opposite to the first surface 81. An electrode terminal may be connected to the second surface 82.

[0056] When the lid body 80 is made of a metal material, it is preferable that the lid body 80 has the corrosion-resistant film described for the barrier layer 52. From the viewpoint of suitably joining the lid body 80 and the main body portion 70A of the covering body 70, the lid body 80 may be provided with at least one of an adhesive film and an adhesive layer. The adhesive film or the adhesive layer may be a single layer or a multilayer, and preferably contains at least a resin material having a polar group. The adhesive layer can be formed by dip coating, dispenser, inkjet, spraying, screen printing, or the like.

[0057] The covering portion 83 is connected to the first surface 81 and the second surface 82, and at least a part thereof is covered by the covering body 70. In the present 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.

[0058] 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 the first direction (in the present embodiment, the LR direction) in a front view 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 the present embodiment, the UD direction) that intersects the first direction in a front view of the lid body 80. In the present embodiment, in a front view of the lid body 80, the first direction and the second direction are orthogonal. The first direction and the second direction may not be orthogonal in a front view 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 the present embodiment, the LR direction) in a front view of the lid body 80.

[0059] 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 the present embodiment, the boundaries 84 to 87 are corners.

[0060] From the viewpoint of suitably heat-sealing the main body portion 70A and the heat-fusible resin layer 53 of the outer film 50, it is preferable that the volume of the main body portion 70A is smaller than the volume of the lid main body 80. When the volume of the main body portion 70A is smaller than the volume of the lid main body 80, when heat-sealing the main body portion 70A and the heat-fusible resin layer 53 of the outer film 50 via the joint portion 70B, since heat is suppressed from being taken away by the main body portion 70A, the time required for heat-sealing can be shortened.

[0061] The joint portion 70B is arranged to suitably join the main body portion 70A and the heat-fusible resin layer 53 of the outer film 50. The joint portion 70B may be, for example, a resin molded product including a resin material. In the present embodiment, the joint portion 70B is a resin molded product. Here, the definition of "comprising a resin material" is the same as the definition described in the main body portion 70A.

[0062] In another example, the joint portion 70B may be an adhesive film that can be joined to a metal material and a resin material. The adhesive film can be arbitrarily selected as long as it can bond the heat-sealable resin layer 53 of the exterior film 50 and the main body portion 70A. 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 applied to the specifications 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 kind of material or different materials, and are appropriately selected according to the material constituting the heat-sealable resin layer 53 of the exterior film 50 and the material constituting the main body portion 70A. The material constituting the heat-sealable resin layer on the side of the adhesive film that is adhered to the main body portion 70A is preferably an acid-modified polyolefin resin graft-modified with an acid such as maleic anhydride. The acid-modified polyolefin is not particularly limited as long as it is an acid-modified polyolefin, but preferably includes a polyolefin graft-modified with an unsaturated carboxylic acid or its anhydride. Specific examples of the polyolefin to be acid-modified include polyethylene such as low-density polyethylene, medium-density polyethylene, high-density polyethylene, and linear low-density polyethylene; crystalline or amorphous polypropylene such as homopolypropylene, block copolymers of polypropylene (for example, block copolymers of propylene and ethylene), and random copolymers of polypropylene (for example, random copolymers of propylene and ethylene); and terpolymers of ethylene-butene-propylene. Among these polyolefins, polyethylene and polypropylene are preferably used, and polypropylene is particularly preferably used.

[0063] The polyolefin to be acid-modified may also be a cyclic polyolefin. For example, a carboxylic acid-modified cyclic polyolefin is a polymer obtained by copolymerizing a part of the monomers constituting the cyclic polyolefin by replacing it with an α,β-unsaturated carboxylic acid or its anhydride, or by block polymerizing or graft polymerizing an α,β-unsaturated carboxylic acid or its anhydride onto the cyclic polyolefin.

[0064] The cyclic polyolefin to be acid-modified is a copolymer of an olefin and a cyclic monomer. Examples of the olefin that is a constituent monomer of the cyclic polyolefin include ethylene, propylene, 4-methyl-1-pentene, butadiene, isoprene, and the like. Examples of the cyclic monomer that is a constituent monomer of the cyclic polyolefin include cyclic alkenes such as norbornene; specifically, cyclic dienes such as cyclopentadiene, dicyclopentadiene, cyclohexadiene, and norbornadiene. Among these polyolefins, cyclic alkenes are preferred, and norbornene is more preferred. Styrene may also be mentioned as a constituent monomer. Examples of the carboxylic acid or its anhydride used for acid modification include maleic acid, acrylic acid, itaconic acid, crotonic acid, maleic anhydride, itaconic anhydride, and the like. It is preferable to use a material of the same type as the material constituting the heat-sealing resin layer 53 of the exterior film 50 for the heat-sealing resin layer on the side adhered to the exterior film 50 of the adhesive film. The adhesive film preferably has adhesiveness. When the adhesive film has adhesiveness, when joining the exterior film 50 and the main body portion 70A, the position of the other with respect to one of the exterior film 50 and the main body portion 70A is less likely to shift. imparting adhesiveness to the adhesive film can be achieved by including an adhesion-imparting resin in the heat-sealing resin layer of the adhesive film.

[0065] The heat-resistant base material layer may be a film or a non-woven fabric having heat resistance. Materials constituting the heat-resistant base material layer are, for example, polyolefin resins, polyamide resins, polyester resins, epoxy resins, acrylic resins, fluorine resins, silicone resins, phenolic resins, polyetherimides, polyimides, polycarbonates, and mixtures or copolymers thereof. The heat-resistant base material layer may have the same layer structure as the heat-fusible resin layer.

[0066] In yet another example, the joint portion 70B may be an adhesive. When the joint portion 70B is an adhesive film or an adhesive layer, the joint portion 70B may be a single layer or a multi-layer, and preferably contains at least a resin material having a polar group. The adhesive layer can be formed by dip coating, dispenser, inkjet, spraying, screen printing, or the like.

[0067] In the present embodiment, the first sealing portion 91 is formed by heat-sealing the opposing surfaces (heat-fusible resin layers 53) of the exterior film 50.

[0068] 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, the base 91X of the first sealing portion 91 is preferably located on the side 43 at the boundary between the first surface 41A and the second surface 42A of the exterior body 40. The base 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, for example, onto the first surface 41A or the second surface 42A of the exterior body 40.

[0069] In this embodiment, the second sealing portion 92 is formed by heat-sealing the heat-sealing resin layer 53 of the exterior film 50 and the lid sealing portion 71 of the main body portion 70A via the joint portion 70B. Hereinafter, the sealing strength between the heat-sealing resin layer 53 of the exterior film 50 and the lid sealing portion 71 of the lid body 60 may be referred to as the sealing strength of the second sealing portion 92. Note that the sealing strength of the second sealing portion 92 is the sealing strength between the heat-sealing resin layer 53 and the lid body 60 in the long-side portion of the lid sealing portion 71, that is, the lid sealing portion 71 extending in the LR (width) direction in FIG. 1A.

[0070] The sealing strength of the second sealing portion 92 is measured as follows. First, a cut is formed in a portion of the outer film 50 that constitutes the first surface 41A of the outer body 40, and three strip members 41X, 41Y, and 41Z arranged in the LR direction (see the two-dot chain line in FIG. 1B) are formed. The width of the three strip members 41X, 41Y, and 41Z in the LR direction is 15 mm. The ends of the strip members 41X, 41Y, and 41Z are joined to the lid body 60 at the second sealing portion 92. The length of the lid body 60 in the LR direction is 45 mm or more. Next, the sealing strength of the strip members 41X, 41Y, and 41Z is measured by pulling the ends of the strip members 41X, 41Y, and 41Z on the side opposite to the ends joined to the lid body 60 upward in the UD direction (the direction opposite to the first surface 41B). The distance between the chucks in the UD direction is 10 mm. The sealing strength of the strip members 41X, 41Y, and 41Z is the peak value of their respective sealing strengths. In the present embodiment, the sealing strength of the second sealing portion 92 is the average value of the sealing 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 with an arbitrary width X mm less than 15 mm are formed, and the sealing strength of the three strip members is measured in the same manner as when the length of the lid body 60 in the LR direction is 45 mm or more. By dividing the obtained sealing strength by the arbitrary width X mm and multiplying by 15, the sealing strength of the three strip members at a width of 15 mm is respectively converted. The sealing strength of the second sealing portion 92 is the average value of the sealing strengths of the three strip members converted to a width of 15 mm. In addition, when the lid body 60 is divided into a plurality of parts including a long side and a short side, the sealing strength of the second sealing portion 92 is the sealing strength at the long side portion of the lid seal portion 71 of the plurality of parts.

[0071] From the viewpoint of suitably maintaining the state in which the electrode body 20 is sealed by the exterior body 40, the sealing strength of the second sealing portion 92 is preferably 40 N / 15 mm or more, more preferably 50 N / 15 mm or more, still more preferably 60 N / 15 mm or more, still more preferably 70 N / 15 mm or more, still more preferably 85 N / 15 mm or more. When the sealing strength of the second sealing portion 92 is 40 N / 15 mm or more, even if the power storage device 10 is used for, for example, several years (less than 10 years), the state in which the electrode body 20 is sealed by the exterior body 40 is suitably maintained. When the sealing strength of the second sealing portion 92 is 85 N / 15 mm or more, even if the power storage device 10 is used for, for example, 10 years or more, the state in which the electrode body 20 is sealed by the exterior body 40 is suitably maintained. The sealing strength of the second sealing portion 92 is preferably 300 N / 15 mm or less. The preferable range of the sealing strength of the second sealing portion 92 is 40 N / 15 mm to 300 N / 15 mm, 50 N / 15 mm to 300 N / 15 mm, 60 N / 15 mm to 300 N / 15 mm, 70 N / 15 mm to 300 N / 15 mm, or 85 N / 15 mm to 300 N / 15 mm.

[0072] <1-2. Method for manufacturing 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, and a fifth step. The first step to the fifth step are, for example, carried out by a manufacturing apparatus for the power storage device 10. At least a part of the first step to the fifth step may be carried out by an operator. Note that the first step to the fifth step are for the sake of convenience in defining 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 respective steps can be arbitrarily changed.

[0073] In the first step (film joining step) of step S1, the manufacturing apparatus joins the main body portion 70A of the covering body 70 and the heat-fusible resin layer 53 of the exterior film 50 by heat sealing or ultrasonic sealing via the joining portion 70B. That is, the first step is a step of forming the second sealing portion 92. Hereinafter, an element in which the covering body 70 and the exterior film 50 are joined is referred to as an intermediate body.

[0074] The second step of step S2 is carried out before or after the first step. In the second step, the manufacturing apparatus electrically connects the lid body 80 and the electrode body 20.

[0075] The third step of step S3 is carried out after the first step and the second step. In the third step, the manufacturing apparatus inserts the electrode body 20 in a state where the lid body 80 is connected through the opening 70YA of the main body portion 70A of the intermediate body into the interior of the intermediate body. By completion of the third step, the electrode body 20 is accommodated inside the intermediate body. The opening 70YA of the main body portion 70A is closed by the lid body 80.

[0076] The fourth step (closing step) of step S4 is carried out after the third step. In the fourth step, the manufacturing apparatus joins the main body portion 70A and the lid body 80 by, for example, welding. The main body portion 70A and the lid body 80 may be joined by caulking, press fitting, shrink fitting, caulking welding, pressure welding, brazing, or an adhesive or the like. When fixing the main body portion 70A and the lid body 80 by caulking, it is preferable to dispose an adhesion assisting member between the main body portion 70A and the lid body 80. The adhesion assisting member is, for example, a foamed material, sponge, resin, or rubber.

[0077] The fifth step of step S5 is carried out after the fourth step. In the fifth step, the manufacturing apparatus forms the first sealing portion 91 by heat sealing the heat-fusible resin layer 53 of the portion including the first edge 50A of the exterior film 50 and the heat-fusible resin layer 53 of the portion including the second edge 50B.

[0078] FIG. 9 is a flowchart showing another example of a method for manufacturing the power storage device 10. The method for manufacturing the power storage device 10 includes, for example, an 11th step, a 12th step, a 13th step, a 14th step, a 15th step, and a 16th step. The 11th to 16th steps are, for example, carried out by a manufacturing apparatus for the power storage device 10. At least a part of the 11th to 16th steps may be carried out by an operator. Note that the 11th to 16th 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.

[0079] In the 11th step of step S11, the manufacturing apparatus arranges a pair of coatings 70 on the sides of the electrode body 20.

[0080] The 12th step of step S12 is carried out after the 11th step. In the 12th step, the manufacturing apparatus winds the exterior film 50 around the electrode body 20 and the coating 70 while tension is applied to the exterior film 50 while restricting the movement of the electrode body 20 and the coating 70 by a restricting means. The restricting means is, for example, a groove into which the electrode body 20 and the coating 70 are fitted. The restricting means may be a device that applies an external force to the electrode body 20 and the coating 70 so that the electrode body 20 and the coating 70 do not move. The restricting means may be a device that applies a force in a direction opposite to the direction in which the exterior film 50 is pulled to the electrode body 20 and the coating 70. Note that the restricting means may include a roller that travels on the exterior film 50 in a state where the exterior film 50 is being pulled in order to remove wrinkles in the exterior film 50.

[0081] The 13th step (film joining step) of step S13 is carried out after the 12th step. In the 13th step, the manufacturing apparatus joins the main body portion 70A of the coating 70 and the heat-fusible resin layer 53 of the exterior film 50 by heat sealing or ultrasonic sealing via a joining portion 70B. That is, the 13th step is a step of forming the second sealing portion 92.

[0082] The 14th step of step S14 is performed after the 13th step. In the 14th step, the manufacturing apparatus electrically connects the electrode body 20 and the lid body 80. The 14th step can be performed outside the covering body 70. Therefore, the 14th step can be easily performed.

[0083] The 15th step (closing step) of step S15 is performed after the 14th step. In the 15th step, the manufacturing apparatus fits the lid body 80 into the opening 70YA of the main body portion 70A, and joins the main body portion 70A and the lid body 80 by welding, for example.

[0084] The 16th step of step S16 is performed after the 15th step. In the 16th step, the manufacturing apparatus heat-seals 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 to form the first sealing portion 91.

[0085] <1-3. Operation and Effect of the Power Storage Device> According to the power storage device 10, since the lid 60 includes the covering body 70 and the lid body 80, the electrode body 20 can be sealed by fitting the lid body 80 into the opening 70YA of the covering body 70. The power storage device 10 can seal the electrode body 20 at an arbitrary timing in the manufacturing process, so that it can be manufactured by various procedures.

[0086] [2. Modification Example] The above embodiment is an exemplification of a form that the power storage device, the lid, the covering body, 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 lid, the covering body, and the manufacturing method of the power storage device according to the present invention can take a form different from the form exemplified in the embodiment. An example thereof 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.

[0087] <2-1. First Modification Example> In the above embodiment, the covering body 70 may not have the joint portion 70B. In the first modification example, from the viewpoint of preferably joining the main body portion 70A and the exterior film 50, it is preferable that the lid seal portion 71 of the main body portion 70A is subjected to a roughening treatment. Specific methods of the roughening treatment include, for example, shot blasting treatment, polishing treatment, alumite treatment, wet etching treatment, plasma treatment, laser treatment, or roughening plating treatment.

[0088] In the first modification example, from the viewpoint of preferably joining the main body portion 70A and the lid main body 80, at least a part of the surface of the lid seal portion 71, in other words, at least a part of the first seal surface 71A, the second seal surface 71B, the third seal surface 71C, and the fourth seal surface 71D may be provided with a corrosion-resistant film. Here, the corrosion-resistant film refers to, for example, a hot water conversion treatment such as bauxite treatment, chemical conversion treatment, anodizing treatment, plating treatment such as nickel or chromium, or a corrosion prevention treatment of applying a coating agent to the surface of the lid seal portion 71 to provide the lid seal portion 71 with corrosion resistance (for example, acid resistance, alkali resistance, etc.). A thin film. Specifically, the corrosion-resistant film means a film that improves the acid resistance of the lid seal portion 71 (acid-resistant film), a film that improves the alkali resistance of the lid seal portion 71 (alkali-resistant film), and the like. 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 excellent in corrosion resistance. Note that these treatments may be included in the definition of the chemical conversion treatment. Also, when the lid seal portion 71 is provided with a corrosion-resistant film, the lid seal portion 71 including the corrosion-resistant film is used.

[0089] <2-2. Second Modification Example> In the above embodiment, the covering body 70 may be arranged such that the second surface 70Y of the main body portion 70A faces the electrode body 20. In the second modification, in the first step shown in FIG. 8 or the 13th step shown in FIG. 9, since the receiver of the heat seal bar can be arranged in the space 79, the first step or the 13th step can be preferably carried out.

[0090] <2-3. Third Modification> In the above embodiment, the covering body 70 may cover at least a part of the first surface 81 and the second surface 82 of the lid body 80 instead of, or in addition to, the covering portion 83 of the lid body 80.

[0091] <2-4. Fourth Modification> In the above embodiment, the exterior film 50 of the power storage device 10 may protrude outside at least one of the two lid bodies 60 in the FB direction. By closing the portion of the exterior film 50 that protrudes outside the lid body 60, the electrode body 20 is sealed. The portion of the exterior film 50 that protrudes outside the lid body 60 may be folded inward so that the outer surfaces of the exterior film 50 contact each other, like a gable-top type container, or may be folded toward an arbitrary surface of the exterior body 40, like a brick-type container.

[0092] <2-5. Fifth Modification> In the above embodiment, the exterior body 40 may not have one of the two lid bodies 60. In this modification, in the FB direction, in the portion where the lid body 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 seventh modification, like a gable-top type container or a brick-type container.

[0093] <2-6. Sixth Modification> 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.

[0094] <2-7. Seventh Modification Example> In the above embodiment, the electrode body 20 is wrapped by a single outer film 50, but it may be wrapped by two or more outer films 50.

Explanation of Reference Numerals

[0095] 10: Energy storage device 20: Electrode body 40: Outer package 50: Outer film 60: Cover 70: Coating 70A: Main body part 70B: Joint part 71: Cover seal part 77: Protrusion 80: Cover body

Claims

1. An electrode body, and an exterior body that seals the electrode body, and includes: The exterior body includes an exterior film that wraps the electrode body, and a lid body that seals the electrode body together with the exterior film, and includes: The lid body includes a lid main body made of a metal material, and a covering body joined to the exterior film and covering at least a part of the edge of the lid main body, and includes: The covering body includes a main body portion (excluding a film as the form of the main body portion) including a lid seal portion joined to the exterior film, The main body portion is made of a metal material and covers at least a part of the side surface of the lid main body A power storage device.

2. The volume of the main body portion is smaller than the volume of the lid main body The power storage device according to claim 1.

3. The covering body includes the lid seal portion, and a protruding portion that protrudes from the lid seal portion and defines a portion covering the edge of the lid main body, and includes: The power storage device according to claim 1 or 2.

4. The covering body further includes a joint portion covering at least a part of the edge of the main body portion The power storage device according to claim 1 or 2.

5. The joint portion is a resin molded product The power storage device according to claim 4.

6. The joint portion is an adhesive film that can be joined to a metal material and a resin material The power storage device according to claim 4.

7. The joint portion is an adhesive The power storage device according to claim 4.

8. A lid body used as an exterior body of a power storage device, including: a lid main body made of a metal material, and a covering body joined to an exterior film constituting the exterior body and covering at least a part of the edge of the lid main body, and includes: The covering body includes a main body portion (excluding a film as the form of the main body portion) including a lid seal portion joined to the exterior film, The main body portion is made of a metal material and covers at least a part of the side surface of the lid main body A lid body.

9. A covering body constituting a lid body used as an exterior body of a power storage device, including: The lid body has a lid main body made of a metal material, The covering body includes a main body portion (excluding a film as the form of the main body portion) including a lid seal portion joined to an exterior film constituting the exterior body, and is configured to cover at least a part of the edge of the lid main body, The main body portion is made of a metal material and covers at least a part of the side surface of the lid main body A covering body.

10. A method for manufacturing a power storage device, wherein The power storage device is An electrode body and, An exterior body that seals the electrode body, and includes: The exterior body An exterior film that wraps the electrode body, and A lid body that seals the electrode body together with the exterior film, and has: The lid body A lid main body formed of a metal material, and A covering body joined to the exterior film and covering at least a part of the edge of the lid main body, and has: The covering body includes a main body part (excluding a film as a form of the main body part) including a lid seal part joined to the exterior film, The main body part is formed of a metal material and covers at least a part of the side surface of the lid main body, A method for manufacturing the power storage device A film joining step of joining the exterior film and the covering body, and A closing step of joining the covering body and the lid main body, which is performed after the film joining step, and includes A method for manufacturing a power storage device.

Images