Electrode body

Abstract

The present invention provides an electrode body that can suppress damage to the curved portions in a structure including a first electrode sheet having a plurality of first laminated portions and a plurality of curved portions connecting adjacent first laminated portions in the lamination direction. [Solution] The electrode body comprises a first electrode portion 11 composed of a first electrode sheet including a plurality of first laminated portions 110 and a plurality of first curved portions 115, and a second electrode portion 12 having a plurality of second laminated portions 120, wherein the plurality of first laminated portions 110 and the plurality of second laminated portions 120 are arranged alternately in the lamination direction, the first electrode sheet includes a first sheet portion including a portion made of a first metal foil that constitutes the first laminated portion and a portion made of a first resin member that constitutes a plurality of first curved portions 115, and a first active material layer 112, the first laminated portion 110 having a first metal foil 111 and a first active material layer 112 on the first metal foil 111, the first active material layer 112 is not provided on the first resin member.

Description

Technical Field

[0001] The present disclosure relates to an electrode body used in a secondary battery.

Background Art

[0002] As a conventional electrode body, in the electrode body composed of a first electrode sheet and a second electrode sheet, Japanese Patent Application Publication No. 2023-504474 (Patent Document 1) discloses a structure in which the first electrode sheet is bent into a multilayer structure (zigzag). The first electrode sheet includes a plurality of first laminated portions and a plurality of curved portions connecting the first laminated portions adjacent in the lamination direction. The first electrode sheet includes an insulating substrate, a conductive layer provided on the insulating substrate, and an active material layer provided on the conductive layer.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In an electrode body in which the first electrode sheet is bent into a multilayer structure (zigzag), a high stress is likely to be applied to the curved portion of the first electrode sheet. When the insulating substrate located in the curved portion is provided with a conductive layer and an active material layer, the curved portion becomes hard, and when stress is applied to the curved portion, the curved portion is likely to break.

[0005] The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide an electrode body capable of suppressing breakage of a curved portion in a structure including a first electrode sheet having a plurality of first laminated portions and a plurality of curved portions connecting the first laminated portions adjacent in the lamination direction.

Means for Solving the Problems

[0006] The electrode body according to this disclosure is used in a secondary battery. The electrode body comprises a first electrode portion composed of a first electrode sheet and a second electrode portion having a different polarity from the first electrode portion. The first electrode sheet includes a plurality of first laminated portions and a plurality of first curved portions arranged side by side in the lamination direction. Each of the plurality of first curved portions connects an adjacent first laminated portion in the lamination direction. The second electrode portion has a plurality of second laminated portions. In the lamination direction, the plurality of first laminated portions and the plurality of second laminated portions are arranged alternately. The first electrode sheet includes a first sheet portion and a first active material layer provided on the first sheet portion. The portion of the first sheet portion that constitutes the first laminated portion is made of a first metal foil. The portion of the first sheet portion that constitutes the plurality of first curved portions is made of a first resin member. The first laminated portion has the first metal foil and the first active material layer provided on the first metal foil. The first active material layer described above is not provided on the first resin member described above.

[0007] According to the above configuration, in a structure in which the first electrode sheet is bent in a zigzag shape, the first curved portion is made solely of resin material. Therefore, when stress is applied to the first curved portion, the resin material deforms by bending, which can suppress cracking or fracture of the first curved portion.

[0008] In the electrode body according to the above disclosure, the second electrode portion may be composed of a second electrode sheet. The second electrode sheet may include a plurality of second laminated portions and a plurality of second curved portions arranged in the lamination direction. Each of the plurality of second curved portions may connect adjacent second laminated portions in the lamination direction. The second electrode sheet may include a second sheet portion and a second active material layer provided on the second sheet portion. The portion of the second sheet portion that constitutes the second laminated portion may be composed of a second metal foil. The portion of the second sheet portion that constitutes the plurality of second curved portions may be composed of a second resin member. The second laminated portion may have the second metal foil and the second active material layer provided on the second metal foil. The second active material layer is not provided on the second resin member.

[0009] According to the above configuration, in a structure in which the second electrode sheet is folded in a zigzag shape, the second curved portion is made solely of resin material. Therefore, when stress is applied to the second curved portion, the resin material deforms by bending, which can suppress cracking or fracture of the second curved portion.

[0010] In the electrode body based on the above disclosure, the thickness of the second resin member may be thinner than that of the second metal foil.

[0011] With the above configuration, the second resin member is thin, making it easier to bend.

[0012] In the electrode body based on the above disclosure, the thickness of the first resin member may be thinner than that of the first metal foil.

[0013] According to the above configuration, the thinness of the first resin member makes it easier to bend.

[0014] The electrode body according to the above disclosure may further include an insulating film that covers a portion of the periphery of the plurality of first laminated portions and the plurality of second laminated portions. The plurality of first curved portions may be exposed from the insulating film.

[0015] According to the above configuration, the first curved portion does not have a first active material layer formed on it, and the first curved portion is made of a resin material. Therefore, it is not necessary to cover the first curved portion with an insulating film. This improves volumetric efficiency when housing the electrode body in the single cell housing case. [Effects of the Invention]

[0016] According to this disclosure, in a structure including a first electrode sheet having a plurality of first laminated portions and a plurality of curved portions connecting adjacent first laminated portions in the lamination direction, it is possible to provide an electrode body that can suppress damage to the curved portions. [Brief explanation of the drawing]

[0017] [Figure 1] This is a perspective view showing a battery according to Embodiment 1. [Figure 2] This is a disassembled perspective view of the battery according to Embodiment 1. [Figure 3] Figure 1 is a cross-sectional view of the battery as seen in the direction of the arrow III-III. [Figure 4] Figure 3 is a cross-sectional view of the electrode body as seen in the direction of the IV-IV line arrow. [Figure 5] This is a diagram showing the first electrode sheet of the electrode body according to Embodiment 1 unfolded. [Figure 6] Figure 5 is a cross-sectional view of the first electrode sheet as seen in the direction of the arrow along the line VI-VI. [Figure 7] This is a cross-sectional view of the electrode body according to Embodiment 2. [Figure 8] This is a diagram showing the second electrode sheet of the electrode body according to Embodiment 2 unfolded. [Figure 9] Figure 8 is a cross-sectional view of the second electrode sheet as seen in the direction of the IX-IX arrow. [Modes for carrying out the invention]

[0018] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the embodiments shown below, the same or common parts are denoted by the same reference numerals in the drawings, and the description thereof will not be repeated.

[0019] (Embodiment 1) FIG. 1 is a perspective view showing a battery according to Embodiment 1. Referring to FIG. 1, the battery 1 according to Embodiment 1 will be described.

[0020] As shown in FIG. 1, the battery 1 is a so-called rectangular battery. The battery 1 may be a secondary battery configured to be capable of charge and discharge, such as a lithium-ion battery or a nickel-hydrogen battery. The battery 1 can be used, for example, as a cell included in a power storage module mounted on an electric vehicle.

[0021] FIG. 2 is an exploded perspective view of the battery according to Embodiment 1. FIG. 3 is a cross-sectional view of the battery of FIG. 1 viewed in the direction of the arrow III-III.

[0022] As shown in FIGS. 1 to 3, the battery 1 includes an electrode body 10, a case 20, a first external terminal 30A, a second external terminal 30B, a first connecting member 40A, a second connecting member 40B, a first seal ring 50A, a second seal ring 50B, a first terminal support portion 60A, a second terminal support portion 60B, an insulating member 70, and a fuse protection portion 80. First, the components of the battery 1 other than the electrode body 10 will be described.

[0023] The case 20 has conductivity. The conductive portion of the case 20 is made of a metal such as aluminum. The case 20 houses the electrode body 10. The case 20 also houses an electrolyte solution (not shown).

[0024] The case 20 includes a case body 21 and a lid 22. The case body 21 includes a bottom wall 21a and a peripheral wall 21b standing up from the bottom wall 21a.

[0025] The bottom wall 21a includes the bottom body 21aa, the pressure relief valve 21ab, the outer protective film 21ac, and the inner protective film 21ad. The peripheral wall 21b rises from the bottom body 21aa. The pressure relief valve 21ab is provided on the bottom body 21aa. The outer protective film 21ac covers the pressure relief valve 21ab from the outside. The inner protective film covers the pressure relief valve 21ab from the inside. The bottom body 21aa and the pressure relief valve 21ab are made of a metal such as aluminum.

[0026] An opening is formed at the upper end of the peripheral wall 21b. The peripheral wall 21b has a substantially rectangular outer shape when viewed from the direction of the opening (normal direction to the opening surface). The opening and the bottom wall 21a are aligned in a first direction D1. The first direction D1 may be the height direction or vertical direction of the battery 1. The peripheral wall 21b is made of a metal such as aluminum.

[0027] The lid 22 includes a lid body 22a, a sealing plug 22b, a plug cover 22c, and an insulating cover 22d.

[0028] The lid body 22a is joined to the peripheral wall 21b by welding or the like so as to close the opening in the peripheral wall 21b. The lid body 22a has a first connecting hole 22aa, a second connecting hole 22ab, and an electrolyte injection hole 22ac formed therein. The electrolyte injection hole 22ac is a through hole for injecting electrolyte into the case body 21 during the manufacturing process of the battery 1.

[0029] The sealing plug 22b seals the injection hole 22ac. The plug cover 22c covers the injection hole 22ac and the sealing plug 22b. The insulating cover 22d covers the injection hole 22ac, the sealing plug 22b, and the plug cover 22c.

[0030] The first external terminal 30A and the second external terminal 30B are provided so as to be exposed to the outside in the battery 1. The first connecting member 40A and the second connecting member 40B are conductive. At least a portion of the first connecting member 40A and the second connecting member 40B are located inside the case 20.

[0031] The first external terminal 30A or the first connecting member 40A is inserted through the first connecting hole 22aa. The first external terminal 30A and the first connecting member 40A are joined to each other. The first connecting member 40A is joined to the electrode body 10. As a result, the first external terminal 30A is electrically connected to the electrode body 10.

[0032] The second external terminal 30B or the second connecting member 40B is inserted through the second connecting hole 22ab. The second external terminal 30B and the second connecting member 40B are joined to each other. The second connecting member 40B is joined to the electrode body 10. As a result, the second external terminal 30B is electrically connected to the electrode body 10.

[0033] 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 aligned in the second direction D2. The second direction D2 is perpendicular to the first direction D1.

[0034] The first seal ring 50A is provided along the first connecting hole 22aa. The first seal ring 50A is provided in the gap between the lid body 22a and the first external terminal 30A, and seals this gap. The second seal ring 50B is provided along the second connecting hole 22ab. The second seal ring 50B is provided in the gap between the lid body 22a and the second external terminal 30B, and seals this gap. The first seal ring 50A and the second seal ring 50B have electrical insulating properties.

[0035] The first terminal support portion 60A is locked to the lid body 22a. The first terminal support portion 60A supports the first external terminal 30A from the outer circumference of the first external terminal 30A. The first terminal support portion 60A includes a first locking ring 61A and a first covering ring 62A. The first locking ring 61A extends in an annular shape so as to surround the first connecting hole 22aa and is locked directly to the lid 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 material that is electrically insulating or has relatively weak conductivity.

[0036] The second terminal support portion 60B is locked to the lid body 22a. The second terminal support portion 60B supports the second external terminal 30B from the outer circumference of the second external terminal 30B. The second terminal support portion 60B includes a second locking ring 61B and a second covering ring 62B. The second locking ring 61B extends in an annular shape so as to surround the second connecting hole 22ab and is locked directly to the lid 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 material.

[0037] The insulating member 70 has electrical insulating properties. The insulating member 70 is placed between the electrode body 10 and the case 20. The insulating member 70 electrically insulates the electrode body 10 and the case 20 from each other. The insulating member 70 includes an insulating bracket 71 and a bottom insulating portion 73.

[0038] The insulating bracket 71 is positioned between the electrode body 10 and the lid body 22a. The insulating bracket 71 is relatively rigid and is in contact with both the electrode body 10 and the lid body 22a. As a result, the electrode body 10 is fixed to the case 20 in the first direction D1.

[0039] The bottom insulating portion 73 is positioned between the electrode body 10 and the bottom wall 21a. The bottom insulating portion 73 is made of a film-like material. In this embodiment, the bottom insulating portion 73 is adhered to the electrode body 10. Furthermore, the bottom insulating portion 73 covers only a portion of the bottom surface of the electrode body 10. Alternatively, the bottom insulating portion 73 may cover the entire bottom surface. In this embodiment, the bottom insulating portion 73 is provided in a one-to-one correspondence with multiple electrode bodies 10.

[0040] As shown in Figure 2, the battery 1 according to this embodiment comprises a plurality of electrode bodies 10. Typically, the battery 1 comprises two electrode bodies 10. These electrode bodies 10 are aligned in a third direction D3. The third direction D3 is perpendicular to both the first direction D1 and the second direction D2.

[0041] The electrode body 10 comprises a plurality of first tabs 150A and a plurality of second tabs 150B, as well as an insulating film 90. One end of the plurality of first tabs 150A is connected to the first metal foil 111 (see Figure 4) of the first electrode portion 11, which will be described later. The other end of the plurality of first tabs 150A is joined to the first connecting member 40A by ultrasonic welding or the like.

[0042] One end of each of the multiple second tabs 150B is connected to the second metal foil 121 (see Figure 4) of the second electrode portion 12, which will be described later. The other end of each of the multiple second tabs 150B is joined to the second connecting member 40B described above by ultrasonic welding or the like.

[0043] The insulating film 90 is configured to cover a portion of the laminate, which is composed of a first laminated portion 110 and a second laminated portion 120 laminated via a separator 13. The insulating film 90 is positioned between the laminate and the peripheral wall 21b. The insulating film 90 covers the laminate in a U-shape. The insulating film 90 is positioned between the side walls and bottom wall 21a of the case 20 in the third direction D3 and the laminate. The insulating film 90 may integrally cover multiple laminates so that the laminates contained in each of the two electrode bodies 10 are fixed to each other. The first curved portion 115 (see Figure 4), which will be described later, is exposed from the insulating film 90.

[0044] Figure 4 is a cross-sectional view of the electrode body in Figure 3, viewed in the direction of the IV-IV arrow. As shown in Figure 4, the electrode body 10 has a first electrode portion 11 and a second electrode portion 12, and a plurality of separators 13.

[0045] The first electrode portion 11 is, for example, a positive electrode. The first electrode portion 11 is composed of a long first electrode sheet, as will be described later. The first electrode portion 11 (first electrode sheet) includes a plurality of first laminated portions 110 and a plurality of first curved portions 115.

[0046] Multiple first stacked sections 110 are arranged side by side with spacing between them in the stacking direction. The stacking direction is parallel to the third direction D3.

[0047] Each of the multiple first laminated sections 110 has a first metal foil 111 and a first active material layer 112 that are laminated in the lamination direction. The first metal foil 111 has a first main surface and a second main surface aligned in the third direction D3, and the first active material layer 112 is provided on each of the first and second main surfaces.

[0048] The first metal foil 111 is made of a metal including, for example, aluminum. Each first metal foil 111 is provided with the first tab 150A described above. The first tab 150A is made, for example, by a portion of the first metal foil 111 extending in a first direction D1. The first active material layer 112 is made of a positive electrode active material layer. Known materials can be used as the positive electrode active material layer.

[0049] Each of the multiple first curved sections 115 connects adjacent first stacked sections 110 in the stacking direction. The multiple first curved sections 115 alternately connect adjacent first stacked sections 110 in the stacking direction on one side and the other side of the second direction D2.

[0050] The second electrode portion 12 has a different polarity from 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 laminated portions 120.

[0051] Each second laminated section 120 is arranged between adjacent first laminated sections 110 in the stacking direction, with a separator 13 in between. That is, in the stacking direction, multiple first laminated sections 110 and multiple second laminated sections 120 are arranged alternately with a separator 13 interposed between them.

[0052] The separator 13 is made of an insulating resin material. The separator 13 may include, for example, a polyolefin resin. The separator 13 may be substantially made of a polyolefin resin. The polyolefin resin may include, for example, at least one selected from the group consisting of polyethylene (PE) and polypropylene (PP).

[0053] The second laminated section 120 has a second metal foil 121 and a second active material layer 122 that are laminated in the lamination direction. The second metal foil 121 has a first main surface and a second main surface aligned in the third direction D3, and the second active material layer 122 is provided on each of the first and second main surfaces.

[0054] The second metal foil 121 is made of a metal including, for example, copper. Each second metal foil 121 is provided with the second tab 150B described above. The second tab 150B is made, for example, by a portion of the second metal foil 121 extending in the first direction D1. The second active material layer 122 is made of a negative electrode active material layer. Known materials can be used as the negative electrode active material layer.

[0055] Figure 5 is a diagram showing the first electrode sheet of the electrode body according to Embodiment 1 unfolded. Figure 6 is a cross-sectional view of the first electrode sheet of Figure 5 as seen in the direction of the arrow VI-VI.

[0056] As shown in Figures 5 and 6, the first electrode portion 11 has a long first sheet portion and a first active material layer 112 provided on the first sheet portion. The first sheet portion is constructed by alternately joining a first metal foil 111 and a first resin member along the longitudinal direction L of the first sheet portion. That is, the portion of the first sheet portion that constitutes the first laminated portion 110 is made of the first metal foil 111, and the portion of the first sheet portion that constitutes the first curved portion 115 is made of the first resin member.

[0057] 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).

[0058] The first active material layer 112 is provided on the first metal foil 111 and not on the first resin member. Furthermore, the thickness of the first resin member in the thickness direction DT may be thinner than that of the first metal foil 111. A thinner first resin member than the first metal foil 111 makes the first resin member constituting the first curved portion 115 more flexible.

[0059] As described above, in the electrode body 10 according to Embodiment 1, the first electrode portion 11 has a structure in which the first electrode sheet is bent in a zigzag shape, and the first active material layer 112 is not formed on the first curved portion 115, and the first curved portion 115 is composed only of the first resin member. Therefore, when stress is applied to the first curved portion 115, the first resin member deforms by bending, which can suppress cracking or fracture of the first curved portion 115.

[0060] Furthermore, as described above, the electrode body 10 is equipped with an insulating film 90 that covers a portion of the laminate, which is composed of a first laminated portion 110 and a second laminated portion 120 laminated via a separator 13, and a plurality of first curved portions 115 are exposed in the second direction D2 from the insulating film 90. As described above, the first active material layer 112 is not formed on the first curved portions 115, and the first curved portions 115 are made of the insulating resin member described above. Therefore, it is not necessary to cover the first curved portions 115 with the insulating film 90, and volumetric efficiency can be improved when housing the electrode body 10 in the housing case 20.

[0061] (Embodiment 2) Figure 7 is a cross-sectional view of the electrode body according to Embodiment 2. Note that Figure 7 is a cross-sectional view of the electrode body perpendicular to the second direction D2. Referring to Figure 7, the electrode body 10X according to Embodiment 2 will be described. The electrode body 10X according to Embodiment 2 can be used in place of the electrode body 10 according to Embodiment 1 in the battery 1 according to Embodiment 1.

[0062] Compared to the electrode body 10 according to Embodiment 1, the electrode body 10X differs in the configuration of the second electrode portion 12X. The other configurations are substantially the same.

[0063] In Embodiment 2, both the first electrode portion 11 and the second electrode portion 12 are made of electrode sheets. Specifically, the first electrode portion 11 is made of a first electrode sheet, similar to Embodiment 1, and includes a plurality of first laminated portions 110 and a plurality of first curved portions 115, although these are not shown in Figure 7.

[0064] 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 laminated sections 120 and a plurality of second curved sections 125.

[0065] Multiple second stacked sections 120 are arranged side by side with spacing between them in the stacking direction. The stacking direction is parallel to the third direction D3.

[0066] Each of the multiple second laminated sections 120 has a second metal foil 121 and a second active material layer 122 that are laminated in the lamination direction. The second metal foil 121 has a first main surface and a second main surface aligned in the third direction D3, and the second active material layer 122 is provided on each of the first and second main surfaces.

[0067] The second metal foil 121 is made of a metal including, for example, copper. Each second metal foil 121 is provided with the second tab 150B described above. The second active material layer 122 is made of a negative electrode active material layer.

[0068] Each of the multiple second curved sections 125 connects adjacent second stacked sections 120 in the stacking direction. The multiple second curved sections 125 alternately connect adjacent second stacked sections 120 in the stacking direction, for example, on one side and the other side of the first direction D1.

[0069] Figure 8 is a diagram showing the second electrode sheet of the electrode body according to Embodiment 2 unfolded. Figure 9 is a cross-sectional view of the second electrode sheet of Figure 8, viewed in the direction of the IX-IX arrow.

[0070] As shown in Figures 8 and 9, the second electrode portion 12 has a long second sheet portion and a second active material layer 122 provided on the second sheet portion. The second sheet portion is formed by alternately joining a second metal foil 121 and a second resin member along the longitudinal direction L. That is, the portion of the second sheet portion that constitutes the second laminated portion 120 is made of the second metal foil 121, and the portion of the second sheet portion that constitutes the second curved portion 125 is made of the second resin member.

[0071] The second resin component has insulating properties. The second resin component can be made of, for example, polyethylene (PE), polypropylene (PP), PPS (polyphenylene sulfide), or PET (polyethylene terephthalate).

[0072] The second active material layer 122 is provided on the second metal foil 121 and not on the second resin member. Furthermore, the thickness of the second resin member in the thickness direction DT may be thinner than that of the second metal foil 121. A thinner second resin member than the second metal foil 121 makes the second resin member constituting the second curved portion 125 more flexible.

[0073] As described above, in the electrode body 10X according to Embodiment 2, the second electrode portion 12X is also constructed by bending the second electrode sheet in a zigzag shape. In this configuration, the second active material layer 122 is not formed on the second curved portion 125, and the second curved portion 125 is made only of the second resin member. Therefore, even when stress is applied to the second curved portion 125, the second resin member flexes and deforms, which prevents cracking or fracture of the second curved portion 125.

[0074] (Other variations) In the embodiments 1 and 2 described above, the first electrode portion 11 is the positive electrode and the second electrode portion 12 is the negative electrode are illustrated as examples, but the invention is not limited to this, and the first electrode portion 11 may be the negative electrode and the second electrode portion 12 may be the positive electrode. In this case, the first metal foil is made of a metal containing copper, and the first active material layer is made of a negative electrode active material layer. The second metal foil is made of a metal containing aluminum, 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.

[0075] The embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims, and all modifications are within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0076] 1 Battery, 10, 10X electrode body, 11 First electrode part, 12, 12X second electrode part, 13 Separator, 20 Case, 21 Case body, 21a Bottom wall, 21aa Bottom body, 21ab Pressure relief valve, 21ad Inner protective film, 21b Peripheral wall, 22 Lid, 22a Lid body, 22aa First connecting hole, 22ab Second connecting hole, 22b Sealing plug, 22c Plug cover, 22d Insulating cover, 30A First external terminal, 30B Second external terminal, 40A First connecting member, 40B Second connecting member, 50A First sealing ring, 50B Second sealing ring, 60A First terminal support part, 60B Second terminal support part, 61A First locking ring, 61B Second locking ring, 62A First covering ring, 62B Second covering ring, 70 Insulating member, 71 Insulating bracket, 73 bottom insulating part, 80 fuse protection part, 90 insulating film, 110 first laminated part, 111 first metal foil, 112 first active material layer, 115 first curved part, 120 second laminated part, 121 second metal foil, 122 second active material layer, 125 second curved part, 150A first tab, 150B second tab, D1 first direction, D2 second direction, D3 third direction.

Claims

1. An electrode body used in a secondary battery, A first electrode portion composed of a first electrode sheet, The device comprises a first electrode portion and a second electrode portion having a different polarity. The first electrode sheet includes a plurality of first laminated portions and a plurality of first curved portions arranged in the lamination direction, Each of the plurality of first curved portions connects the adjacent first stacked portions in the stacking direction. The second electrode portion has a plurality of second laminated portions, In the aforementioned 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 provided on the first sheet portion. The portion of the first sheet portion that constitutes the first laminated portion is made of a first metal foil, The portions of the first sheet portion that constitute the plurality of first curved portions are made of a first resin member. The first laminated portion comprises the first metal foil and the first active material layer provided on the first metal foil. The electrode body is provided in which the first active material layer is not located on the first resin member.

2. The second electrode portion is composed of a second electrode sheet, The second electrode sheet includes a plurality of second laminated portions and a plurality of second curved portions arranged in the lamination direction, Each of the plurality of second curved portions connects the adjacent second stacked portions in the stacking direction. The second electrode sheet comprises a second sheet portion and a second active material layer provided on the second sheet portion. The portion of the second sheet portion that constitutes the second laminated portion is made of a second metal foil, The portions of the second sheet portion that constitute the plurality of second curved portions are made of a second resin member, The second laminated portion comprises the second metal foil and the second active material layer provided on the second metal foil. The electrode body according to claim 1, wherein the second active material layer is not provided on the second resin member.

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

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

5. The device further comprises an insulating film that covers a portion of the periphery of the plurality of first laminated portions and the plurality of second laminated portions, The electrode body according to claim 1, wherein the plurality of first curved portions are exposed from the insulating film.

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