Electrode body

Abstract

The invention relates to an electrode body. The present invention is provided with: a first electrode section comprising a plurality of first laminated sections and a plurality of first curved sections, and comprising a first electrode sheet; and a second electrode portion having a plurality of second laminated portions, the plurality of first laminated portions and the plurality of second laminated portions being alternately arranged in the lamination direction, the first electrode sheet including a first sheet portion and a first active material layer, the first sheet portion including a portion constituting the first laminated portion made of a first metal foil and a portion constituting a plurality of first curved portions made of a first resin member, and the first sheet portion including a portion constituting the first curved portion made of a second resin member and a portion constituting the second curved portion made of a second resin member. The first laminated portion has a first metal foil and a first active material layer provided on the first metal foil, and the first active material layer is not provided on the first resin member.

Description

Technical Field

[0001] This disclosure relates to electrode bodies for secondary batteries. Background Technology

[0002] As a conventional electrode body, Japanese Patent Application Publication No. 2023-504474 discloses a structure in which the first electrode sheet is bent into a multi-layered structure (zigzag shape) in an electrode body composed of a first electrode sheet and a second electrode sheet. The first electrode sheet includes a plurality of first layer stacks and a plurality of bent portions that connect adjacent first layer stacks in the stacking direction. The first electrode sheet includes an insulating substrate, a conductive layer disposed on the insulating substrate, and an active material layer disposed on the conductive layer. Summary of the Invention

[0003] In an electrode body where the first electrode sheet is bent into a multi-layered (zigzag) structure, high stress is easily applied to the bent portion of the first electrode sheet. When a conductive layer and an active material layer are provided on the insulating substrate located at the bent portion, the bent portion becomes hardened, and it is easy to break when stress is applied to the bent portion.

[0004] This disclosure is made in view of the aforementioned problems, and the object of this disclosure is to provide an electrode body that, in a construction including a first electrode sheet having a plurality of first stacked portions and a plurality of bent portions connecting adjacent first stacked portions in the stacking direction, can suppress breakage of the bent portions.

[0005] The electrode body disclosed herein is an electrode body for a secondary battery. This electrode body includes a first electrode portion formed of a first electrode sheet and a second electrode portion with a polarity different from that of the first electrode portion. The first electrode sheet includes a plurality of first stacked portions arranged in a stacking direction and a plurality of first bent portions. Each of the plurality of first bent portions is connected to adjacent first stacked portions in the stacking direction. The second electrode portion has a plurality of second stacked portions. In the stacking direction, the plurality of first stacked portions and the plurality of second stacked portions are alternately arranged. The first electrode sheet includes a first sheet portion and a first active material layer disposed on the first sheet portion. The portion of the first sheet portion constituting the first stacked portion is made of a first metal foil. The portion of the first sheet portion constituting the plurality of first bent portions is made of a first resin member. The first stacked portion has the first metal foil and the first active material layer disposed on the first metal foil. The first active material layer is not disposed on the first resin component.

[0006] According to the above configuration, in the structure where the first electrode sheet is bent into a zigzag shape, the first bent portion is composed solely of a resin component. Therefore, when stress is applied to the first bent portion, the flexural deformation of the resin component can suppress the occurrence of cracks or breakage in the first bent portion.

[0007] In the electrode body based on the present disclosure, the second electrode portion may be composed of a second electrode sheet. The second electrode sheet may include a plurality of second stacked portions arranged in the stacking direction and a plurality of second bent portions. Each of the plurality of second bent portions can connect adjacent second stacked portions in the stacking direction. The second electrode sheet may include a second sheet portion and a second active material layer disposed on the second sheet portion. The portion of the second sheet portion constituting the second stacked portion may be composed of a second metal foil. The portion of the second sheet portion constituting the plurality of second bent portions may be composed of a second resin member. The second stacked portion may have the second metal foil and the second active material layer disposed on the second metal foil. The second active material layer is not disposed on the second resin member.

[0008] Based on the above configuration, in the structure where the second electrode sheet is bent into a zigzag shape, the second bend is composed solely of a resin component. Therefore, when stress is applied to the second bend, the flexural deformation of the resin component can suppress the formation of cracks or breakage in the second bend.

[0009] In the electrode body based on the present disclosure, the thickness of the second resin component may be thinner than that of the second metal foil.

[0010] Based on the above configuration, the second resin component is thin and easily bent.

[0011] In the electrode body based on the present disclosure, the thickness of the first resin component may be thinner than that of the first metal foil.

[0012] According to the above configuration, the first resin component is thin and easy to bend.

[0013] The electrode body based on the present disclosure may further include an insulating film that covers a portion of the periphery of the plurality of first stacked portions and the plurality of second stacked portions. The plurality of first curved portions may be exposed from the insulating film.

[0014] Based on the above configuration, a first active material layer is not formed at the first bend, and the first bend is made of a resin component. Therefore, it is not necessary to cover the first bend with an insulating film. As a result, volumetric efficiency can be improved when the electrode body is housed within the housing of a single cell.

[0015] The foregoing and other objects, features, aspects and advantages of the present invention will become apparent from the following detailed description relating to the invention, which is understood in conjunction with the accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a perspective view showing the battery of Embodiment 1.

[0017] Figure 2 This is an exploded perspective view of the battery according to Embodiment 1.

[0018] Figure 3 Observe in the direction of the arrow on line III-III Figure 1 A cross-sectional view of the battery.

[0019] Figure 4 Observe in the direction of the arrow on line IV-IV. Figure 3 A cross-sectional view of the electrode body.

[0020] Figure 5 This is a diagram showing the unfolded first electrode sheet of the electrode body in Embodiment 1.

[0021] Figure 6 Observe in the direction of the arrow on line VI-VI. Figure 5 A cross-sectional view of the first electrode sheet.

[0022] Figure 7 This is a cross-sectional view of the electrode body in Embodiment 2.

[0023] Figure 8 This is a diagram showing the unfolded second electrode sheet of the electrode body in Embodiment 2.

[0024] Figure 9 Observe in the direction of the arrow on the IX-IX line. Figure 8 A cross-sectional view of the second electrode plate. Detailed Implementation

[0025] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Furthermore, in the embodiments shown below, the same reference numerals are used to label the same or common parts in the drawings, and their description will not be repeated.

[0026] (Implementation Method 1)

[0027] Figure 1 This is a perspective view showing the battery according to Embodiment 1. (Refer to...) Figure 1 The battery 1 of Embodiment 1 will be described.

[0028] like Figure 1 As shown, battery 1 is a so-called square battery. Battery 1 can be a rechargeable secondary battery, such as a lithium-ion battery or a nickel-metal hydride battery. Battery 1 can be used, for example, as a unit included in an energy storage module mounted in an electric vehicle.

[0029] Figure 2 This is an exploded perspective view of the battery according to Embodiment 1. Figure 3Observe in the direction of the arrow on line III-III Figure 1 A cross-sectional view of the battery.

[0030] like Figures 1-3 As shown, the battery 1 includes an electrode body 10, a housing 20, a first external terminal 30A, a second external terminal 30B, a first connecting member 40A, a second connecting member 40B, a first sealing ring 50A, a second sealing ring 50B, a first terminal support 60A, a second terminal support 60B, an insulating member 70, and a fuse protection part 80. First, the components of the battery 1 other than the electrode body 10 will be described.

[0031] The housing 20 is conductive. The conductive parts of the housing 20 are made of a metal such as aluminum. The housing 20 houses the electrode body 10. The housing 20 also houses an electrolyte (not shown).

[0032] The housing 20 includes a housing body 21 and a cover 22. The housing body 21 includes a bottom wall 21a and a peripheral wall 21b rising from the bottom wall 21a.

[0033] The bottom wall 21a includes a bottom body 21aa, a pressure relief valve 21ab, an outer protective membrane 21ac, and an inner protective membrane 21ad. The peripheral wall 21b rises from the bottom body 21aa. The pressure relief valve 21ab is disposed on the bottom body 21aa. The outer protective membrane 21ac covers the pressure relief valve 21ab from the outside. The inner protective membrane 21ad covers the pressure relief valve 21ab from the inside. The bottom body 21aa and the pressure relief valve 21ab are made of metal such as aluminum.

[0034] An opening is formed at the upper end of the peripheral wall 21b. The peripheral wall 21b has a generally rectangular shape when viewed from the opening direction (the normal direction of the opening surface). The opening and the bottom wall 21a are aligned in a first direction D1. The first direction D1 can be the height direction of the battery 1 or the vertical direction. The peripheral wall 21b is made of a metal such as aluminum.

[0035] The cover 22 includes a cover body 22a, a sealing bolt 22b, a bolt cover 22c, and an insulating cover 22d.

[0036] The cover body 22a is joined to the peripheral wall 21b by welding or the like to close the opening of the peripheral wall 21b. A first connecting hole 22aa, a second connecting hole 22ab, and an electrolyte injection hole 22ac are formed in the cover body 22a. The electrolyte injection hole 22ac is a through hole used to inject electrolyte into the casing body 21 during the manufacturing process of the battery 1.

[0037] A sealing plug 22b seals the injection hole 22ac. A plug cover 22c covers the injection hole 22ac and the sealing plug 22b. An insulating cover 22d covers the injection hole 22ac, the sealing plug 22b, and the plug cover 22c.

[0038] The first external terminal 30A and the second external terminal 30B are configured to be exposed to the outside within the battery 1. The first connecting structural member 40A and the second connecting structural member 40B are conductive. At least a portion of the first connecting structural member 40A and the second connecting structural member 40B is disposed inside the housing 20.

[0039] The first external terminal 30A or the first connecting member 40A is inserted into the first connecting hole 22aa. The first external terminal 30A and the first connecting member 40A are engaged with each other. The first connecting member 40A is engaged with the electrode body 10. Thus, the first external terminal 30A is electrically connected to the electrode body 10.

[0040] The second external terminal 30B or the second connecting member 40B is inserted into the second connecting hole 22ab. The second external terminal 30B and the second connecting member 40B are engaged with each other. The second connecting member 40B is engaged with the electrode body 10. Thus, the second external terminal 30B is electrically connected to the electrode body 10.

[0041] Furthermore, in this embodiment, the first external terminal 30A is the positive terminal, and the second external terminal 30B is the negative terminal. The first external terminal 30A and the second external terminal 30B are arranged in the second direction D2. The second direction D2 is a direction orthogonal to the first direction D1.

[0042] A first sealing ring 50A is disposed along the first connecting hole 22aa. The first sealing ring 50A is disposed in the gap between the cover body 22a and the first external terminal 30A, sealing the gap. A second sealing ring 50B is disposed along the second connecting hole 22ab. The second sealing ring 50B is disposed in the gap between the cover body 22a and the second external terminal 30B, sealing the gap. The first sealing ring 50A and the second sealing ring 50B are electrically insulating.

[0043] The first terminal support portion 60A is engaged (stopped) to the cover body 22a. The first terminal support portion 60A supports the first external terminal 30A from its outer periphery. The first terminal support portion 60A includes a first locking ring 61A and a first covering ring 62A. The first locking ring 61A extends annularly around the first connecting hole 22aa and is directly engaged with the cover body 22a. The first covering ring 62A covers the first locking ring 61A. The first locking ring 61A supports the first external terminal 30A via the first covering ring 62A. The first covering ring 62A is made of a resin member having electrical insulation or weak conductivity.

[0044] The second terminal support portion 60B is engaged with the cover body 22a. The second terminal support portion 60B supports the second external terminal 30B from its outer periphery. The second terminal support portion 60B includes a second locking ring 61B and a second covering ring 62B. The second locking ring 61B extends annularly around the second connecting hole 22ab and is directly engaged with the cover body 22a. The second covering ring 62B covers the second locking ring 61B. The second locking ring 61B supports the second external terminal 30B via the second covering ring 62B. The second covering ring 62B is made of an electrically insulating resin component.

[0045] The insulating member 70 is electrically insulating. The insulating member 70 is disposed between the electrode body 10 and the housing 20. The insulating member 70 electrically insulates the electrode body 10 and the housing 20 from each other. The insulating member 70 includes an insulating bracket 71 and a bottom insulating portion 73.

[0046] An insulating bracket 71 is disposed between the electrode body 10 and the cover body 22a. The insulating bracket 71 has high rigidity and is in contact with both the electrode body 10 and the cover body 22a. Thus, the electrode body 10 is fixed to the housing 20 in the first direction D1.

[0047] A bottom insulating portion 73 is disposed between the electrode body 10 and the bottom wall 21a. The bottom insulating portion 73 is composed of a film-like component. In this embodiment, the bottom insulating portion 73 is bonded to the electrode body 10. Alternatively, the bottom insulating portion 73 may only cover a portion of the bottom surface of the electrode body 10. Furthermore, the bottom insulating portion 73 may also completely cover the bottom surface. In this embodiment, the bottom insulating portions 73 are provided one-to-one with the plurality of electrode bodies 10.

[0048] like Figure 2 As shown, the battery 1 of this embodiment includes a plurality of electrode bodies 10. Typically, the battery 1 includes two electrode bodies 10. These electrode bodies 10 are arranged in a third direction D3. The third direction D3 is a direction orthogonal to both the first direction D1 and the second direction D2.

[0049] The electrode body 10 includes a plurality of first tabs 150A, a plurality of second tabs 150B, and an insulating film 90. One end of the plurality of first tabs 150A is connected to the first metal foil 111 of the first electrode portion 11 (described later). Figure 4 The other end of the plurality of first tabs 150A is joined to the aforementioned first connecting structural member 40A by means of ultrasonic welding or the like.

[0050] One end of the plurality of second electrodes 150B and the second metal foil 121 of the second electrode section 12 described later (see reference) Figure 4 The other end of the plurality of second tabs 150B is joined to the aforementioned second connecting structural member 40B by means of ultrasonic welding or the like.

[0051] The insulating film 90 is configured to cover a portion of a laminate consisting of a first laminate 110 and a second laminate 120 stacked with spacers 13. The insulating film 90 is disposed between the laminate and the peripheral wall 21b. The insulating film 90 covers the laminate in a U-shape. The insulating film 90 is disposed between the laminate and the side walls and bottom wall 21a of the housing 20 in the third direction D3. The insulating film 90 may also integrally cover multiple laminates, such that the laminates included in each of the two electrode bodies 10 are mutually fixed. The first curved portion 115 (see below) Figure 4 It is exposed from the insulating film at 90°.

[0052] Figure 4 Observe in the direction of the arrow on line IV-IV. Figure 3 A cross-sectional view of the electrode body. (e.g.) Figure 4 As shown, the electrode body 10 has a first electrode portion 11 and a second electrode portion 12, and a plurality of separators 13.

[0053] The first electrode portion 11 is, for example, a positive electrode. As described later, the first electrode portion 11 is composed of a strip-shaped first electrode sheet. The first electrode portion 11 (first electrode sheet) includes a plurality of first stacked portions 110 and a plurality of first bent portions 115.

[0054] Multiple first-layer stacked portions 110 are arranged at intervals in the stacking direction. The stacking direction is parallel to the third direction D3.

[0055] Each of the plurality of first stacked portions 110 has a first metal foil 111 and a first active material layer 112 stacked in the stacking direction. The first metal foil 111 has a first main surface and a second main surface arranged in the third direction D3, and the first active material layer 112 is respectively disposed on the first main surface and the second main surface.

[0056] The first metal foil 111 is, for example, made of an aluminum-containing metal. Each of the first metal foils 111 is provided with the aforementioned first tab 150A. The first tab 150A is formed, for example, by a portion of the first metal foil 111 extending in the first direction D1. The first active material layer 112 is composed of a positive electrode active material layer. Well-known positive electrode active material layers can be used as the positive electrode active material layer.

[0057] Each of the plurality of first bends 115 is connected to an adjacent first stacked portion 110 in the stacking direction. The plurality of first bends 115 are alternately connected to the adjacent first stacked portions 110 in the stacking direction on one side and the other side of the second direction D2.

[0058] The second electrode portion 12 has a different polarity than the first electrode portion 11. The second electrode portion 12 is, for example, a negative electrode. The second electrode portion 12 includes a plurality of second stacked portions 120.

[0059] Each second stack 120 is arranged with a spacer 13 between adjacent first stack 110s in the stacking direction. That is, in the stacking direction, a plurality of first stack 110s and a plurality of second stack 120s are arranged alternately with spacers 13 between them.

[0060] The separator 13 is made of an insulating resin component. The separator 13 may, for example, contain a polyolefin resin. The separator 13 may also be substantially made of a polyolefin resin. The polyolefin resin may, for example, contain at least one selected from polyethylene (PE) and polypropylene (PP).

[0061] The second stacked portion 120 has a second metal foil 121 and a second active material layer 122 stacked in the stacking direction. The second metal foil 121 has a first main surface and a second main surface arranged in the third direction D3, and the second active material layer 122 is respectively provided on the first main surface and the second main surface.

[0062] The second metal foil 121 is, for example, made of a copper-containing metal. Each of the second metal foils 121 is provided with the aforementioned second tab 150B. The second tab 150B is formed, for example, by extending a portion of the second metal foil 121 in the first direction D1. The second active material layer 122 is composed of a negative electrode active material layer. Well-known negative electrode active material layers can be used as the negative electrode active material layer.

[0063] Figure 5 This is a diagram showing the unfolded first electrode sheet of the electrode body in Embodiment 1. Figure 6 Observe in the direction of the arrow on line VI-VI. Figure 5 A cross-sectional view of the first electrode sheet.

[0064] like Figure 5 as well as Figure 6 As shown, the first electrode portion 11 has a strip-shaped first sheet portion and a first active material layer 112 disposed on the first sheet portion. The first sheet portion is formed by alternately bonding a first metal foil 111 and a first resin member along the long side direction L of the first sheet portion. That is, the portion of the first sheet portion constituting the first laminate portion 110 is composed of the first metal foil 111, and the portion of the first sheet portion constituting the first curved portion 115 is composed of the first resin member.

[0065] The first resin component has insulating properties. The first resin component can be made of, for example, polyethylene (PE), polypropylene (PP), PPS (polyphenylene sulfide), or PET (polyethylene terephthalate).

[0066] The first active material layer 112 is disposed on the first metal foil 111, but not on the first resin member. Furthermore, the thickness of the first resin member in the thickness direction DT can be thinner than the first metal foil 111. Because the thickness of the first resin member is thinner than the first metal foil 111, the first resin member constituting the first bending portion 115 is easier to bend.

[0067] As described above, in the electrode body 10 of Embodiment 1, in the structure where the first electrode portion 11 is a bent first electrode sheet, the first active material layer 112 is not formed in the first bent portion 115, and the first bent portion 115 is only composed of the first resin member. Therefore, when stress is applied to the first bent portion 115, the bending deformation of the first resin member can suppress the occurrence of cracks or breakage of the first bent portion 115.

[0068] Furthermore, as described above, the electrode body 10 includes an insulating film 90 covering a portion of a laminate consisting of a first laminate 110 and a second laminate 120 stacked with spacers 13, and a plurality of first bends 115 protrude from the insulating film 90 in the second direction D2. As described above, a first active material layer 112 is not formed in the first bends 115, and the first bends 115 are made of the aforementioned insulating resin member. Therefore, the first bends 115 can be omitted from the insulating film 90, and volumetric efficiency can be improved when the electrode body 10 is housed within the housing 20.

[0069] (Implementation Method 2)

[0070] Figure 7 This is a cross-sectional view of the electrode body according to Embodiment 2. Furthermore, Figure 7 This is a cross-sectional view of the electrode body perpendicular to the second direction D2. (Refer to...) Figure 7 The electrode body 10X of Embodiment 2 will be described. The electrode body 10X of Embodiment 2 can replace the electrode body 10 of Embodiment 1 and be used in the battery 1 of Embodiment 1.

[0071] The electrode body 10X differs from the electrode body 10 of Embodiment 1 in that the second electrode portion 12X has a different configuration. The other configurations are largely the same.

[0072] In Embodiment 2, both the first electrode portion 11 and the second electrode portion 12 are composed of electrode sheets. Specifically, the first electrode portion 11 is composed of a first electrode sheet similar to that in Embodiment 1, although... Figure 7 It is not illustrated, but includes multiple first layer stacks 110 and multiple first bends 115.

[0073] The second electrode section 12X is composed of a second electrode sheet. The second electrode section 12X (second electrode sheet) includes a plurality of second stacked sections 120 and a plurality of second bent sections 125.

[0074] Multiple second-layer stacks 120 are arranged at intervals in the stacking direction. The stacking direction is parallel to the third direction D3.

[0075] Each of the multiple second-layer stacks 120 has a second metal foil 121 and a second active material layer 122 stacked in the stacking direction. The second metal foil 121 has a first main surface and a second main surface arranged in the third direction D3, and the second active material layer 122 is respectively disposed on the first main surface and the second main surface.

[0076] The second metal foil 121 is made of, for example, a copper-containing metal. Each second metal foil 121 is provided with the aforementioned second tab 150B. The second active material layer 122 is composed of a negative electrode active material layer.

[0077] Each of the plurality of second bends 125 is connected to an adjacent second stacked portion 120 in the stacking direction. For example, the plurality of second bends 125 are alternately connected to adjacent second stacked portions 120 in the stacking direction on one side and the other side in the first direction D1.

[0078] Figure 8 This is a diagram showing the unfolded second electrode sheet of the electrode body in Embodiment 2. Figure 9 Observe in the direction of the arrow on line IX-IX Figure 8 A cross-sectional view of the second electrode plate.

[0079] like Figure 8 as well as Figure 9 As shown, the second electrode portion 12 has a strip-shaped second sheet portion and a second active material layer 122 disposed on the second sheet portion. The second sheet portion is formed by alternately bonding a second metal foil 121 and a second resin member along the long side direction L. That is, the portion of the second sheet portion that constitutes the second laminate portion 120 is composed of the second metal foil 121, and the portion of the second sheet portion that constitutes the second curved portion 125 is composed of the second resin member.

[0080] The second resin component is insulating. The second resin component can be made of, for example, polyethylene (PE), polypropylene (PP), PPS (polyphenylene sulfide), or PET (polyethylene terephthalate).

[0081] The second active material layer 122 is disposed on the second metal foil 121, but not on the second resin member. Furthermore, the thickness of the second resin member in the thickness direction DT can be thinner than that of the second metal foil 121. Because the thickness of the second resin member is thinner than that of the second metal foil 121, the second resin member constituting the second bending portion 125 is easier to bend.

[0082] As described above, in the electrode body 10X of Embodiment 2, the second electrode portion 12X is also constructed by bending the second electrode sheet into a zigzag shape. In this configuration, the second active material layer 122 is not formed in the second bent portion 125, and the second bent portion 125 is constructed solely of the second resin member. Therefore, even when stress is applied to the second bent portion 125, the flexural deformation of the second resin member can suppress the formation of cracks or breakage of the second bent portion 125.

[0083] (Other variations)

[0084] In embodiments 1 and 2 described above, the case where the first electrode portion 11 is a positive electrode and the second electrode portion 12 is a negative electrode was illustrated, but this is not a limitation; the first electrode portion 11 may also be a negative electrode and the second electrode portion 12 a positive electrode. In this case, the first metal foil is made of a copper-containing metal, and the first active material layer is made of a negative electrode active material layer. Furthermore, the second metal foil is made of an aluminum-containing metal, and the second active material layer is made of a positive electrode active material layer. The size of the negative electrode active material layer may be larger than that of the positive electrode active material layer.

[0085] Embodiments of the present invention have been described, but should be considered illustrative rather than restrictive in all respects. The scope of the invention is defined by the claims and is intended to include all modifications within the scope and equivalent meaning of the claims.

Claims

1. An electrode body for use in a secondary battery, comprising: The first electrode section is composed of a first electrode plate; and The second electrode portion has a different polarity than the first electrode portion. The first electrode sheet includes a plurality of first stacked portions and a plurality of first bent portions arranged in the stacking direction. Each of the plurality of first curved portions will connect adjacent first stacked portions in the stacking direction. The second electrode portion has multiple second-layer stacked portions. In the stacking direction, the plurality of first stacked portions and the plurality of second stacked portions are arranged alternately. The first electrode sheet includes a first sheet portion and a first active material layer disposed on the first sheet portion. The portion of the first sheet that constitutes the first laminate is composed of a first metal foil. The portion of the first sheet that constitutes the plurality of first curved portions is composed of a first resin component. The first layer has the first metal foil and the first active material layer disposed on the first metal foil. The first active material layer is not disposed on the first resin component.

2. The electrode body according to claim 1, The second electrode portion is composed of a second electrode sheet. The second electrode sheet includes a plurality of second stacked portions and a plurality of second bent portions arranged in the stacking direction. Each of the plurality of second curved portions connects adjacent second stacked portions in the stacking direction. The second electrode sheet includes a second sheet portion and a second active material layer disposed on the second sheet portion. The portion of the second sheet that constitutes the second laminate is composed of a second metal foil. The portion of the second piece constituting the plurality of second curved portions is composed of a second resin component. The second layer has the second metal foil and the second active material layer disposed on the second metal foil. The second active material layer is not disposed on the second resin component.

3. The electrode body according to claim 2, The thickness of the second resin component is thinner than that of the second metal foil.

4. The electrode body according to any one of claims 1 to 3, The thickness of the first resin component is thinner than that of the first metal foil.

5. The electrode body according to claim 1, It also includes an insulating film that covers a portion of the periphery of the plurality of first layers and the plurality of second layers. The plurality of first bends are exposed from the insulating film.

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