Wound electrode assembly

Abstract

The present invention relates to a wound electrode assembly provided with separators in which first electrode regions and second electrode regions, each of which is provided with an electrode layer, are alternately arranged at intervals. The wound electrode body is formed by winding a separator in a state in which the direction in which the first electrode region and the second electrode region are arranged is along the winding direction.

Description

Technical Field

[0001] This disclosure relates to wound electrode bodies. Background Technology

[0002] As a conventional wound electrode, Japanese Patent Application Publication No. 2019-096592 discloses the following structure: At least one of a sheet-like positive electrode member and a negative electrode member is formed by sequentially laminating a conductive layer and an active material layer on the surface of an insulating substrate, with a spacer disposed between the positive and negative electrode members, and then wound together. A through-hole penetrating in the thickness direction is provided in the insulating substrate. Summary of the Invention

[0003] When a sheet-shaped first electrode member, obtained by sequentially stacking a first conductive layer and a first active material layer on an insulating substrate, and a sheet-shaped second electrode member, obtained by stacking a second conductive layer and a second active material layer on a metal foil or an insulating substrate, are wound together with a separator, the number of components increases.

[0004] This disclosure is made in view of the aforementioned problems, and the purpose of this disclosure is to provide a wound electrode body capable of reducing the number of components.

[0005] The wound electrode body based on this disclosure includes a separator that alternately arranges a first electrode region and a second electrode region, on which an electrode layer is provided, at intervals. The separator is wound in a manner where the first electrode region and the second electrode region are arranged along the winding direction.

[0006] According to the above configuration, by winding a separator on which an electrode layer is directly formed to form a wound electrode body, the number of components can be reduced.

[0007] In the wound electrode body based on the present disclosure, a first electrode layer may be provided in the first electrode region, and a second electrode layer with a polarity different from that of the first electrode layer may be provided in the second electrode region. The separator may have a first main surface and a second main surface. The first electrode layer may include a first conductive layer and a first active material layer. The second electrode layer may include a second conductive layer and a second active material layer. The first conductive layer and the first active material layer may be sequentially stacked from the separator side on each of the first main surface and the second main surface located in the first electrode region. The second conductive layer and the second active material layer may be sequentially stacked from the separator side on each of the first main surface and the second main surface located in the second electrode region.

[0008] According to the above configuration, in the configuration where a first electrode layer is formed in the first electrode region and a second electrode layer is formed in the second electrode region, the number of components for winding the electrode body can be reduced.

[0009] In the wound electrode body based on the present disclosure, the first conductive layer may have a first exposed portion on one side of its width direction orthogonal to the winding direction, exposing the first active material layer. The second conductive layer may have a second exposed portion on one side of its width direction, exposing the second active material layer. The wound electrode body may further include a plurality of first tabs connected to the first exposed portions and a plurality of second tabs connected to the second exposed portions.

[0010] According to the above configuration, current can flow to the first electrode layer and the second electrode layer via the first electrode tab and the second electrode tab.

[0011] In the wound electrode body based on the present disclosure, a first electrode layer and a second electrode layer with a polarity different from that of the first electrode layer can be provided in each of the first electrode region and the second electrode region, separated by the separator. The separator can have a first main surface and a second main surface. The first electrode layer can include a first conductive layer and a first active material layer. The second electrode layer can include a second conductive layer and a second active material layer. The first conductive layer and the first active material layer can be stacked from the separator side on each of the first main surface located in the first electrode region and the first main surface located in the second electrode region. The second conductive layer and the second active material layer can be sequentially stacked from the separator side on each of the second main surface located in the first electrode region and the second main surface located in the second electrode region.

[0012] According to the above configuration, in the configuration where a first electrode layer and a second electrode layer are formed in the first electrode region and the second electrode region respectively, the number of components for winding the electrode body can be reduced.

[0013] In the wound electrode body based on the present disclosure, in the first electrode region, the first conductive layer may have a first exposed portion on one side of its width direction orthogonal to the winding direction, exposing the first active material layer. In the second electrode region, the second conductive layer may have a second exposed portion on one side of its width direction, exposing the second active material layer. The wound electrode body may further include: a plurality of first tabs that are not connected to the second conductive layer in the first electrode region but are connected to the first exposed portion of the first conductive layer; and a plurality of second tabs that are not connected to the first conductive layer in the second electrode region but are connected to the second exposed portion of the second conductive layer.

[0014] According to the above configuration, current can flow to the first electrode layer and the second electrode layer via the first electrode tab and the second electrode tab.

[0015] In the wound electrode body based on the present disclosure, the length of each region of the first electrode region and the second electrode region along the winding direction may increase as the region moves from the inside to the outside of the winding direction.

[0016] Based on the above configuration, the first electrode layer and the second electrode layer can be efficiently positioned opposite each other in the radial direction centered on the winding axis.

[0017] In the wound electrode body based on the present disclosure, the separator may have a non-forming region where the electrode layer is not disposed at one end of the winding direction, the other end of the winding direction, and between the first electrode region and the second electrode region. The non-forming region may be disposed on the inner side of the innermost electrode layer, between the radially adjacent electrode layers centered on the winding axis, and on the outer side of the outermost electrode layer.

[0018] According to the above configuration, it is possible to suppress direct contact between the innermost electrode layers, direct contact between the radially adjacent first and second electrode layers, and direct contact between the outermost electrode layer and the housing located on the outside of the wound electrode body.

[0019] The above 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

[0020] Figure 1 This is a perspective view showing the battery of Embodiment 1.

[0021] Figure 2 This is an exploded perspective view of the battery according to Embodiment 1.

[0022] Figure 3 It is Figure 1 The battery shown is a cross-sectional view when viewed in the direction of the arrow along line III-III.

[0023] Figure 4 It is Figure 3 The diagram shows a cross-sectional view of the wound electrode body as viewed in the direction of the arrow along line IV-IV.

[0024] Figure 5 It is Figure 3 The cross-sectional view of the wound electrode body as seen when viewed in the direction of the arrow on line VV.

[0025] Figure 6It is Figure 3 The diagram shows a schematic cross-sectional view of the wound electrode body when viewed partially in the direction of the arrow along line VI-VI.

[0026] Figure 7 This is an unfolded view of the wound electrode body according to Embodiment 1.

[0027] Figure 8 It is Figure 7 The cross-sectional view of the wound electrode body as seen when viewed in the direction of the arrow along line VIII-VIII.

[0028] Figure 9 It is Figure 5 The enlarged partial cross-sectional view of region IX of the wound electrode body is shown.

[0029] Figure 10 It is Figure 6 The enlarged partial cross-sectional view of region X of the wound electrode body is shown.

[0030] Figure 11 This is a cross-sectional view of the wound electrode body according to Embodiment 2.

[0031] Figure 12 This is a cross-sectional view of the wound electrode body in the unfolded state according to Embodiment 2.

[0032] Figure 13 This is a partial cross-sectional view showing the arrangement of the first tab in the wound electrode body of Embodiment 2.

[0033] Figure 14 This is a partial cross-sectional view showing the arrangement of the second tab in the wound electrode body of Embodiment 2. Detailed Implementation

[0034] 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 or common parts will be labeled with the same reference numerals in the drawings, and their descriptions will not be repeated.

[0035] (Implementation Method 1)

[0036] 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.

[0037] 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.

[0038] Figure 2This is an exploded perspective view of the battery according to Embodiment 1. Figure 3 It is Figure 1 A cross-sectional view of the battery when viewed in the direction of the arrow along line III-III.

[0039] like Figures 1-3 As shown, the battery 1 includes a wound 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 wound electrode body 10 will be described.

[0040] 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 wound electrode body 10. The housing 20 also houses an electrolyte (not shown).

[0041] 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.

[0042] 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 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.

[0043] 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.

[0044] The cover 22 includes a cover body 22a, a sealing bolt 22b, a bolt cover 22c, and an insulating cover 22d.

[0045] 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.

[0046] 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.

[0047] The first external terminal 30A and the second external terminal 30B are arranged to be exposed to the outside in 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.

[0048] 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 wound electrode body 10. Thus, the first external terminal 30A is electrically connected to the wound electrode body 10.

[0049] 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 wound electrode body 10. Thus, the second external terminal 30B is electrically connected to the wound electrode body 10.

[0050] 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.

[0051] 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.

[0052] The first terminal support portion 60A is engaged with 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.

[0053] 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.

[0054] The insulating member 70 is electrically insulating. The insulating member 70 is disposed between the wound electrode body 10 and the housing 20. The insulating member 70 electrically insulates the wound electrode body 10 and the housing 20 from each other. The insulating member 70 includes an insulating bracket 71, a peripheral insulating portion 72, and a bottom insulating portion 73.

[0055] An insulating bracket 71 is disposed between the wound electrode body 10 and the cover body 22a. The insulating bracket 71 has high rigidity and is in contact with both the wound electrode body 10 and the cover body 22a. Thus, the wound electrode body 10 is fixed to the housing 20 in the first direction D1.

[0056] The peripheral insulating portion 72 is disposed between the wound electrode body 10 and the peripheral wall 21b. The wound electrode body 10 is composed of a film-like component.

[0057] A bottom insulating portion 73 is disposed between the wound 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 wound electrode body 10. Alternatively, the bottom insulating portion 73 may only cover a portion of the bottom surface of the wound electrode body 10. Furthermore, the bottom insulating portion 73 may also completely cover the bottom surface.

[0058] like Figure 2 As shown, the battery 1 of this embodiment includes a plurality of wound electrode bodies 10. Typically, the battery 1 includes two wound electrode bodies 10. These wound electrode bodies 10 are arranged in a third direction D3. The third direction D3 is orthogonal to both the first direction D1 and the second direction D2. Furthermore, the peripheral insulating portion 72 may integrally cover the plurality of wound electrode bodies 10, thereby fixing these wound electrode bodies 10 to each other. Additionally, in this embodiment, the insulating member 70 includes a plurality of bottom insulating portions 73 corresponding one-to-one with each of the plurality of wound electrode bodies 10.

[0059] Hereinafter, one of the plurality of wound electrode bodies 10 will be described. Furthermore, each of the plurality of wound electrode bodies 10 may have the configuration shown below.

[0060] Figure 4 It is Figure 3 A cross-sectional view of the wound electrode body viewed in the direction of the arrow along line IV-IV. Figure 5 It is Figure 3 A cross-sectional view of the wound electrode body viewed in the direction of the arrow on line VV. Figure 6 It is Figure 3 A schematic cross-sectional view of the wound electrode body when viewed partially in the direction of the arrow along line VI-VI.

[0061] like Figures 4-6 As shown, the wound electrode body 10 is constructed by winding a separator 110 on which an electrode layer is formed. Specifically, in the separator 110, first electrode regions R1 on which the first electrode layer 200A is provided are alternately arranged at intervals (see reference). Figure 7 ) and the second electrode region R2, on which the second electrode layer 200B is provided (refer to Figure 7 The first electrode region R1 and the second electrode region R2 are arranged in the winding direction DR and wound together.

[0062] Furthermore, in this embodiment, the case where the first electrode layer 200A is the negative electrode and the second electrode layer 200B is the positive electrode is illustrated, but it is not limited to this. Alternatively, the first electrode layer 200A may be the positive electrode and the second electrode layer 200B may be the negative electrode.

[0063] The separator 110 is made of an insulating resin component. The separator 110 may, for example, contain a polyolefin resin. The separator 110 may, for example, be substantially made of a polyolefin resin. The polyolefin resin may, for example, contain at least one selected from polyethylene (PE) and polypropylene (PP).

[0064] The wound electrode body 10 has a plurality of first tabs 150A and a plurality of second tabs 150B.

[0065] One end of each of the plurality of first tabs 150A is connected to the first conductive layer 210A of the first electrode layer 200A, which will be described later. The other end of each of the plurality of first tabs 150A is joined to the first connecting member 40A described above by means of ultrasonic welding or the like.

[0066] One end of each of the plurality of second tabs 150B is connected to the second conductive layer 210B of the second electrode layer 200B, which will be described later. The other end of each of the plurality of second tabs 150B is joined to the second connecting member 40B described above by means of ultrasonic welding or the like.

[0067] Figure 7 This is an unfolded view of the wound electrode body according to Embodiment 1. Figure 8 It is Figure 7 The cross-sectional view of the wound electrode body as seen when viewed in the direction of the arrow along line VIII-VIII.

[0068] like Figure 7 as well as Figure 8 As shown, the separator 110 has a non-electrode region R0 where no electrode layer is formed, located at one end 110c and the other end 110d in the winding direction, and between the first electrode region R1 and the second electrode region R2. One end 110c forms the outer end in the winding state, and the other end 110d forms the inner end in the winding state. The separator 110 has a first main surface 110a and a second main surface 110b. The first main surface 110a faces outward, and the second main surface 110b faces inward.

[0069] As described above, a first electrode layer 200A is provided in the first electrode region R1. The first electrode layer 200A includes a first conductive layer 210A and a first active material layer 220A.

[0070] On each of the first main surface 110a and the second main surface 110b located in the first electrode region R1, a first conductive layer 210A and a first active material layer 220A are sequentially stacked from the separator 110 side. That is, in the first electrode region R1, a first conductive layer 210A is provided on the first main surface 110a and the second main surface 110b, and a first active material layer 220A is stacked on the first conductive layer 210A on the first main surface 110a and the first conductive layer 210A on the second main surface 110b.

[0071] The first conductive layer 210A is provided, for example, by vapor deposition of a copper-containing metal onto the first main surface 110a and the second main surface 110b. The first conductive layer 210A may also be a film-like component bonded to the separator 110. The first active material layer 220A is, for example, a negative electrode active material layer.

[0072] On each of the first main surface 110a and the second main surface 110b located in the second electrode region R2, a second conductive layer 210B and a second active material layer 220B are sequentially stacked from the separator 110 side. That is, in the second electrode region R2, a second conductive layer 210B is provided on the first main surface 110a and the second main surface 110b, and a second active material layer 220B is stacked on the second conductive layer 210B on the first main surface 110a and the second conductive layer 210B on the second main surface 110b.

[0073] The second conductive layer 210B is provided, for example, by vapor deposition of an aluminum-containing metal onto the first main surface 110a and the second main surface 110b. The second conductive layer 210B may also be a film-like component bonded to the separator 110. The second active material layer 220B is, for example, a positive electrode active material layer.

[0074] like Figure 4 as well as Figure 7 As shown, when the separator 110 is wound up, a non-forming region R0 is arranged inside the innermost electrode layer (more specifically, the first electrode layer), between the radially adjacent electrode layers (the first electrode layer and the second electrode layer) centered on the winding axis, and outside the outermost electrode layer (more specifically, the first electrode layer).

[0075] Therefore, it is possible to prevent direct contact between the innermost electrode layers and each other, direct contact between the first electrode layer 200A and the second electrode layer 200B which are radially adjacent to each other, and direct contact between the outermost electrode layer and the housing 20 located on the outside of the wound electrode body 10.

[0076] Furthermore, the lengths of each region of the first electrode region R1 and the second electrode region R2 along the winding direction increase from the inside to the outside of the winding direction. The length of the outermost first electrode layer 200A along the winding direction is longer than the length of the second electrode layer 200B disposed on the inner periphery of the winding direction following the first electrode layer 200A. Additionally, the length of the second electrode layer 200B along the winding direction is longer than the length of the first electrode layer 200A disposed on the inner periphery of the winding direction following the second electrode layer 200B. In other words, the length of the second electrode layer 200B along the winding direction is longer than the length of the innermost first electrode layer 200A along the winding direction.

[0077] Therefore, the first electrode layer 200A and the second electrode layer 200B can be efficiently positioned facing each other radially about the winding axis. The outermost first electrode layer 200A and the second electrode layer 200B, which is disposed on the inner circumferential side of the winding direction following the first electrode layer 200A, are facing each other radially. Furthermore, the second electrode layer 200B and the first electrode layer 200A, which is disposed on the inner circumferential side of the winding direction following the second electrode layer 200B, are facing each other radially.

[0078] Figure 9 It is Figure 5 The enlarged partial cross-sectional view of region IX of the wound electrode body is shown. Figure 10 It is Figure 6 The enlarged partial cross-sectional view of region X of the wound electrode body is shown.

[0079] like Figure 7 ,as well as Figure 9 , Figure 10As shown, the wound electrode body 10 includes a first protective portion 300A, a second protective portion 300B, a lower-side first protective portion 400A, and a lower-side second protective portion 400B. The first protective portion 300A and the lower-side first protective portion 400A protect the upper and lower ends of the first active material layer 220A in the first electrode region R1. The second protective portion 300B and the lower-side second protective portion 400B protect the upper and lower ends of the second active material layer 220B in the second electrode region R2.

[0080] The first protective part 300A is electrically insulating, for example, made of ceramic. The first protective part 300A covers the upper part of the first active material layer 220A. The first protective part 300A is further covered by a separator 110 between the first tab 150A and the first active material layer 220A.

[0081] The second protective portion 300B is electrically insulating, for example, made of ceramic. The second protective portion 300B covers the upper part of the second active material layer 220B. The second protective portion 300B is further covered by a separator 110 between the second tab 150B and the second active material layer 220B.

[0082] The lower side first protective part 400A has electrical insulation properties, for example, it is made of ceramic. The lower side first protective part 400A covers the lower part of the first active material layer 220A.

[0083] The lower side second protective part 400B is electrically insulating, for example, made of ceramic. The lower side second protective part 400B covers the lower part of the second active material layer 220B.

[0084] like Figure 9 As shown, the first conductive layer 210A has a first exposed portion 210C on one side of the width direction D0, which is orthogonal to the winding direction, and which protrudes from the first active material layer 220A. Furthermore, the width direction D0 is parallel to the aforementioned first direction D1. The first exposed portion 210C is provided on the first main surface 110a and the second main surface 110b.

[0085] The separator 110 has a strip-shaped main body 111 and a plurality of protruding tabs 112 protruding from the main body 111 toward one side in the width direction D0. The plurality of protruding tabs 112 are provided at positions corresponding to the plurality of first tabs 150A, 150B. The aforementioned first exposed portion 210C is mainly provided in the protruding tabs 112.

[0086] In each first electrode region R1, a plurality of first electrode tabs 150A are connected to the first exposed portion 210C. Specifically, a plurality of first electrode tabs 150A are connected to the portion of the first exposed portion 210C that is exposed from the first protective portion 300A.

[0087] The first tab 150A includes a first foil portion 151 and a second foil portion 152. The first foil portion 151 and the second foil portion 152 are connected to the first exposed portion 210C in a state where the upper end of the separator 110 and the aforementioned first exposed portion 210C are sandwiched in the thickness direction DT. The first foil portion 151 and the second foil portion 152 are joined together by ultrasonic welding or the like.

[0088] like Figure 10 As shown, the second conductive layer 210B has a second exposed portion 210D on one side of the width direction D0, which is orthogonal to the winding direction, that exposes from the second active material layer 220B. The second exposed portion 210D is provided on the first main surface 110a and the second main surface 110b. The second exposed portion 210D is mainly provided on the protruding sheet portion 112.

[0089] In each second electrode region R2, a plurality of second tabs 150B are connected to the second exposed portion 210D. Specifically, a plurality of second tabs 150B are connected to the portion of the second exposed portion 210D that is exposed from the second protective portion 300B.

[0090] The second tab 150B includes a third foil portion 153 and a fourth foil portion 154. The third foil portion 153 and the fourth foil portion 154 are connected to the second exposed portion 210D in a state in which the upper end of the separator 110 and the aforementioned second exposed portion 210D are sandwiched in the thickness direction DT. The third foil portion 153 and the fourth foil portion 154 are joined together by ultrasonic welding or the like.

[0091] As described above, the wound electrode body 10 of this embodiment 1 is constructed by winding a separator 110, in which the first electrode region R1 and the second electrode region R2, on which the electrode layer is provided, are arranged alternately at intervals. As a result, compared with the configuration obtained by winding the positive electrode and the negative electrode with the separator in a state between the positive electrode and the negative electrode, the number of components can be reduced.

[0092] Furthermore, in Embodiment 1, the first active material layer 220A and the second active material layer 220B are shown to be the same size, but this is not a limitation. The size of the first active material layer 220A may also be larger than the size of the second active material layer 220B. In this case, when the first active material layer 220A is set as the negative electrode, the precipitation of dendrites from the second active material layer 220B can be suppressed.

[0093] (Implementation Method 2)

[0094] Figure 11 This is a cross-sectional view of the wound electrode body according to Embodiment 2. Figure 12 This is a cross-sectional view showing the wound electrode body of Embodiment 2 in its unfolded state. Furthermore, Figure 11Compared with the implementation method 1 Figure 3 The schematic cross-sectional view of the wound electrode body shown corresponds to a partial view taken along the arrow direction of line VI-VI. Figure 12 Compared with the implementation method 1 Figure 7 The cross-sectional view of the wound electrode body shown corresponds to that viewed in the direction of the arrow along line VIII-VIII. (Refer to...) Figure 11 as well as Figure 12 The wound electrode body 10X of Embodiment 2 will be described.

[0095] like Figure 11 as well as Figure 12 As shown, the main difference between the wound electrode body 10X of Embodiment 2 and the wound electrode body 10 of Embodiment 1 is the arrangement of the first electrode layer 200A and the second electrode layer 200B. Additionally, if using... Figure 13 , Figure 14 As will be described later, the configurations of the first electrode 150A and the second electrode 150B are also different. The other configurations are generally the same.

[0096] In Embodiment 2, in each of the first electrode region R1 and the second electrode region R2, the first electrode layer 200A and the second electrode layer 200B are arranged with the separator 110 sandwiched between them.

[0097] Specifically, on the first main surface 110a of the separator 110 located in the first electrode region R1 and on the first main surface 110a of the separator 110 located in the second electrode region R2, a first conductive layer 210A and a first active material layer 220A are sequentially stacked from the separator 110 side. On the second main surface 110b of the separator 110 located in the first electrode region R1 and on the second main surface 110b of the separator 110 located in the second electrode region R2, a second conductive layer 210B and a second active material layer 220B are sequentially stacked from the separator 110 side.

[0098] Furthermore, the size of the first active material layer 220A can be larger than the size of the second active material layer 220B. Specifically, the upper end of the first active material layer 220A in the width direction D0 can be located above the upper end of the second active material layer 220B in the width direction D0. Additionally, the lower end of the first active material layer 220A in the width direction D0 can be located below the lower end of the second active material layer 220B in the width direction D0.

[0099] Figure 13 as well as Figure 14 This is a partial cross-sectional view showing the arrangement of the first electrode tab and the second electrode tab in the wound electrode body of Embodiment 2. Furthermore, Figure 13 Compared with Implementation Method 1 Figure 9Correspondingly, specifically, with the Figure 5 The enlarged partial cross-sectional view of region XI of the wound electrode body is shown. Figure 14 Compared with Implementation Method 1 Figure 10 Correspondingly, specifically, with the Figure 6 The enlarged partial cross-sectional view of region X of the wound electrode body is shown.

[0100] like Figure 13 as well as Figure 14 As shown, in Embodiment 2, in each of the first electrode region R1 and the second electrode region R2, the upper ends of the first active material layer 220A and the upper ends of the second active material layer 220B are respectively covered by the first protective portion 300A and the second protective portion 300B. Similarly, although not shown here, in each of the first electrode region R1 and the second electrode region R2, the lower ends of the first active material layer 220A and the lower ends of the second active material layer 220B are respectively covered by the aforementioned lower-side first protective portion 400A and lower-side second protective portion 400B.

[0101] like Figure 13 As shown, in the first electrode region R1, the first conductive layer 210A has a first exposed portion 210C exposed from the first active material layer 220A on one side of the width direction D0 orthogonal to the winding direction, and the second conductive layer 210B has a second exposed portion 210D exposed from the second active material layer 220B on one side of the width direction D0.

[0102] In the first electrode region R1, the first tab 150A is not connected to the second conductive layer 210B, but is connected to the first exposed portion 210C of the first conductive layer 210A. More specifically, the first tab 150A is bonded to the portion of the first exposed portion 210C that is exposed from the first protective portion 300A. The first tab 150A is, for example, made of a plate-shaped metal foil. Furthermore, as long as the first tab 150A is plate-shaped, it can also be formed by stacking multiple metal foils.

[0103] like Figure 14 As shown, in the second electrode region R2, the first conductive layer 210A has a first exposed portion 210C exposed from the first active material layer 220A on one side of the width direction D0 orthogonal to the winding direction, and the second conductive layer 210B has a second exposed portion 210D exposed from the second active material layer 220B on one side of the width direction D0.

[0104] In the second electrode region R2, the second tab 150B is not connected to the first conductive layer 210A, but is connected to the second exposed portion 210D of the second conductive layer 210B. More specifically, the second tab 150B is engaged with the portion of the second exposed portion 210D that is exposed from the second protective portion 300B. The second tab 150A is, for example, made of a plate-shaped metal foil. Furthermore, as long as the second tab 150A is plate-shaped, it can also be made of multiple metal foils stacked together.

[0105] Even in the configuration described above, the wound electrode body 10X is constructed by winding the spacer 110, in which the first electrode region R1 and the second electrode region R2, on which the electrode layer is provided, are arranged alternately at intervals. Therefore, the wound electrode body 10X of Embodiment 2 can achieve approximately the same effect as the wound electrode body 10 of Embodiment 1.

[0106] Embodiments of the present invention have been described, but it should be considered that the embodiments disclosed herein are illustrative rather than restrictive in all inventions. 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. A wound electrode body, It has a separator in which a first electrode region and a second electrode region, on which electrode layers are provided, are alternately arranged at intervals. The separator is wound in a manner where the first electrode region and the second electrode region are arranged along the winding direction.

2. The wound electrode body according to claim 1, A first electrode layer is provided in the first electrode region. A second electrode layer with a polarity different from that of the first electrode layer is provided in the second electrode region. The separator has a first main surface and a second main surface. The first electrode layer includes a first conductive layer and a first active material layer. The second electrode layer includes a second conductive layer and a second active material layer. On each of the first main surface and the second main surface located in the first electrode region, the first conductive layer and the first active material layer are sequentially stacked from the separator side. On each of the first main surface and the second main surface located in the second electrode region, the second conductive layer and the second active material layer are sequentially stacked from the separator side.

3. The wound electrode body according to claim 2, The first conductive layer has a first exposed portion on one side in the width direction orthogonal to the winding direction, which is exposed from the first active material layer. The second conductive layer has a second exposed portion on one side in the width direction, which is exposed from the second active material layer. The wound electrode body also includes: A plurality of first tabs connected to the first exposed portion; and Multiple second tabs connected to the second exposed portion.

4. The wound electrode body according to claim 1, In each of the first electrode region and the second electrode region, a first electrode layer and a second electrode layer with a polarity different from that of the first electrode layer are disposed apart from the separator. The separator has a first main surface and a second main surface. The first electrode layer includes a first conductive layer and a first active material layer. The second electrode layer includes a second conductive layer and a second active material layer. On each of the first main surfaces located in the first electrode region and the second electrode region, a first conductive layer and a first active material layer are sequentially stacked from the separator side. On the second main surface located in the first electrode region and on the second main surface located in the second electrode region, the second conductive layer and the second active material layer are sequentially stacked from the separator side.

5. The wound electrode body according to claim 4, In the first electrode region, the first conductive layer has a first exposed portion on one side in the width direction orthogonal to the winding direction, which exposes the first active material layer. In the second electrode region, the second conductive layer has a second exposed portion on one side in the width direction, which exposes from the second active material layer. The wound electrode body also includes: Multiple first tabs, which are not connected to the second conductive layer in the first electrode region but are connected to the first exposed portion of the first conductive layer; and Multiple second tabs are provided, which are not connected to the first conductive layer in the second electrode region but are connected to the second exposed portion of the second conductive layer.

6. The wound electrode body according to any one of claims 1 to 5, As the length of each region of the first electrode region and the second electrode region increases along the winding direction from the inside to the outside.

7. The wound electrode body according to any one of claims 1 to 5, The separator has a non-forming region where the electrode layer is not disposed at one end in the winding direction, at the other end in the winding direction, and between the first electrode region and the second electrode region. The non-formed region is disposed inside the innermost electrode layer, between the radially adjacent electrode layers centered on the winding axis, and outside the outermost electrode layer.

Images