Winding electrode

Abstract

To provide a wound electrode body that can reduce the number of parts. [Solution] The wound electrode body 10 includes a separator 110 in which a first electrode region R1 and a second electrode region R2, each provided with an electrode layer, are alternately arranged with a gap between them. The wound electrode body 10 is formed by winding the separator 110 such that the direction in which the first electrode region R1 and the second electrode region R2 are aligned is aligned with the winding direction.

Description

Technical Field

[0001] The present disclosure relates to a wound electrode body.

Background Art

[0002] As a conventional wound electrode body, in Japanese Patent Application Laid-Open No. 2019-096592 (Patent Document 1), an electrode member in which a conductive layer and an active material layer are laminated in this order on the surface of an insulating substrate is used for at least one of a sheet-like positive electrode member and a negative electrode member, a separator is disposed between the positive electrode member and the negative electrode member, and a structure in which these are wound is disclosed. The insulating substrate is provided with through holes penetrating in the thickness direction.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When winding a sheet-like first electrode member in which a first conductive layer and a first active material layer are sequentially laminated on an insulating base material and a sheet-like second electrode member in which a second conductive layer and a second active material layer are laminated on a metal foil or an insulating base material via a separator, the number of parts increases.

[0005] The present disclosure has been made in view of the above problems, and an object of the present disclosure is to provide a wound electrode body capable of reducing the number of parts.

Means for Solving the Problems

[0006] The wound electrode body according to this disclosure comprises a separator in which a first electrode region and a second electrode region, each provided with an electrode layer, are alternately arranged with a gap between them. The separator is wound in such a way that the direction in which the first electrode region and the second electrode region are aligned is aligned with the winding direction.

[0007] According to the above configuration, the number of parts can be reduced because a wound electrode body is formed by winding a separator on which an electrode layer is directly formed.

[0008] In the wound electrode body according to the above disclosure, the first electrode region may be provided with a first electrode layer, and the second electrode region may be provided with a second electrode layer having a polarity different from that of the first electrode layer. 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. 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 may be laminated in this order 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 may be laminated in this order from the separator side.

[0009] According to the above configuration, in a configuration in which 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 parts in the wound electrode body can be reduced.

[0010] In the wound electrode body according to the above disclosure, the first conductive layer may have a first exposed portion exposed from the first active material layer on one side in the width direction perpendicular to the winding direction. The second conductive layer may have a second exposed portion exposed from the second active material layer on one side in the width direction. The wound electrode body may further comprise a plurality of first tabs connected to the first exposed portion and a plurality of second tabs connected to the second exposed portion.

[0011] According to the above configuration, current can be passed through the first tab and the second tab to the first electrode layer and the second electrode layer.

[0012] In the wound electrode body according to the above disclosure, the first electrode region and the second electrode region may each be provided with a first electrode layer and a second electrode layer having a different polarity from the first electrode layer, separated by a separator. 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 main surface located in the first electrode region and the first main surface located in the second electrode region may each have the first conductive layer and the first active material layer laminated in this order from the separator side. The second main surface located in the first electrode region and the second main surface located in the second electrode region may each have the second conductive layer and the second active material layer laminated in this order from the separator side.

[0013] According to the above configuration, in a configuration in which 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 parts in the wound electrode body can be reduced.

[0014] In the wound electrode body according to the above disclosure, in the first electrode region, the first conductive layer may have a first exposed portion exposed from the first active material layer on one side in the width direction perpendicular to the winding direction. In the second electrode region, the second conductive layer may have a second exposed portion exposed from the second active material layer on one side in the width direction. The wound electrode body may further include, in the first electrode region, a plurality of first tabs connected to the first exposed portion of the first conductive layer without being connected to the second conductive layer, and in the second electrode region, a plurality of second tabs connected to the second exposed portion of the second conductive layer without being connected to the first conductive layer.

[0015] According to the above configuration, current can be passed through the first tab and the second tab to the first electrode layer and the second electrode layer.

[0016] In the wound electrode body according to the above disclosure, the length of each region of the first electrode region and the second electrode region may increase along the winding direction as one moves from the inside to the outside in the winding direction.

[0017] According to the above configuration, the first electrode layer and the second electrode layer can be efficiently positioned facing each other in the radial direction centered on the winding axis.

[0018] In the wound electrode body according to the above disclosure, the separator may have non-formed regions where the electrode layer is not provided at one end in the winding direction and the other end in the winding direction, and between the first electrode region and the second electrode region. The non-formed regions may be located inside the innermost electrode layer, between adjacent electrode layers in the radial direction centered on the winding axis, and outside the outermost electrode layer.

[0019] With the above configuration, it is possible to suppress direct contact between the innermost electrode layers, direct contact between the first and second electrode layers that are adjacent to each other in the radial direction, and direct contact between the outermost electrode layer and a component such as a case located outside the wound electrode body. [Effects of the Invention]

[0020] According to this disclosure, it is possible to provide a wound electrode body that can reduce the number of parts. [Brief explanation of the drawing]

[0021] [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] It is a cross-sectional view of the wound electrode body shown in FIG. 3 as viewed in the direction of the arrow along line IV-IV. [Figure 5] It is a cross-sectional view of the wound electrode body shown in FIG. 3 as viewed in the direction of the arrow along line V-V. [Figure 6] It is a schematic cross-sectional view of the wound electrode body shown in FIG. 3 partially as viewed in the direction of the arrow along line VI-VI. [Figure 7] It is a developed view of the electrode body of Embodiment 1. [Figure 8] It is a cross-sectional view of the wound electrode body shown in FIG. 7 as viewed in the direction of the arrow along line VIII-VIII. [Figure 9] It is a partial cross-sectional view showing an enlarged region IX of the wound electrode body shown in FIG. 5. [Figure 10] It is a partial cross-sectional view showing an enlarged region X of the wound electrode body shown in FIG. 6. [Figure 11] It is a cross-sectional view of the wound electrode body according to Embodiment 2. [Figure 12] It is a cross-sectional view of the wound electrode body according to Embodiment 2 in a developed state. [Figure 13] It is a partial cross-sectional view showing the installation mode of the first tab in the wound electrode body according to Embodiment 2. [Figure 14] It is a partial cross-sectional view showing the installation mode of the second tab in the wound electrode body according to Embodiment 2.

Mode for Carrying Out the Invention

[0022] [[ID=X]] 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.

[0023] (Embodiment 1) E FIG. 1 is a perspective view showing a battery according to Embodiment 1. With reference to FIG. 1, the battery 1 according to Embodiment 1 will be described.

[0024] As shown in Figure 1, battery 1 is a so-called prismatic battery. Battery 1 may 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 cell included in an energy storage module installed in an electric vehicle.

[0025] Figure 2 is an exploded perspective view of the battery according to Embodiment 1. Figure 3 is a cross-sectional view of the battery of Figure 1, viewed in the direction of the arrow III-III.

[0026] As shown in Figures 1 to 3, the battery 1 comprises a wound 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 sealing ring 50A, a second sealing ring 50B, a first terminal support part 60A, a second terminal support part 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.

[0027] Case 20 is conductive. The conductive portion of Case 20 is made of a metal such as aluminum. Case 20 houses the wound electrode body 10. Case 20 also houses an electrolyte (not shown).

[0028] 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 that rises from the bottom wall 21a.

[0029] 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.

[0030] 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.

[0031] The lid 22 includes a lid body 22a, a sealing plug 22b, a plug cover 22c, and an insulating cover 22d.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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 wound electrode body 10. As a result, the first external terminal 30A is electrically connected to the wound electrode body 10.

[0036] 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 wound electrode body 10. As a result, the second external terminal 30B is electrically connected to the wound electrode body 10.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] The insulating member 70 has electrical insulating properties. The insulating member 70 is positioned between the wound electrode body 10 and the case 20. The insulating member 70 electrically insulates the wound electrode body 10 and the case 20 from each other. The insulating member 70 includes an insulating bracket 71, a circumferential insulating portion 72, and a bottom insulating portion 73.

[0042] The insulating bracket 71 is positioned between the wound electrode body 10 and the lid body 22a. The insulating bracket 71 is relatively rigid and is in contact with both the wound electrode body 10 and the lid body 22a. As a result, the wound electrode body 10 is fixed to the case 20 in the first direction D1.

[0043] The circumferential insulating portion 72 is positioned between the wound electrode body 10 and the circumferential wall 21b. The wound electrode body 10 is made of a film-like material.

[0044] The bottom insulating portion 73 is positioned between the wound 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 wound electrode body 10. Furthermore, the bottom insulating portion 73 covers only a portion of the bottom surface of the wound electrode body 10. However, the bottom insulating portion 73 may cover the entire bottom surface.

[0045] As shown in Figure 2, the battery 1 according to this embodiment comprises a plurality of wound electrode bodies 10. Typically, the battery 1 comprises two wound electrode bodies 10. These wound 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. The circumferential insulating portion 72 may integrally cover the plurality of wound electrode bodies 10 so that they are fixed to each other. In this embodiment, the insulating member 70 also includes a plurality of bottom insulating portions 73 so as to correspond one-to-one with the plurality of wound electrode bodies 10.

[0046] In the following description, one of the multiple wound electrode bodies 10 will be explained. Note that each of the multiple wound electrode bodies 10 may have the configuration shown below.

[0047] Figure 4 is a cross-sectional view of the wound electrode body in Figure 3, viewed in the direction of the IV-IV arrow. Figure 5 is a cross-sectional view of the wound electrode body in Figure 3, viewed in the direction of the VV arrow. Figure 6 is a schematic cross-sectional view of the wound electrode body in Figure 3, partially viewed in the direction of the VI-VI arrow.

[0048] As shown in Figures 4 to 6, the wound electrode body 10 is constructed by winding a separator 110 on which an electrode layer is formed. Specifically, the separator 110 has a first electrode region R1 (see Figure 7) on which a first electrode layer 200A is provided and a second electrode region R2 (see Figure 7) on which a second electrode layer 200B is provided, which are arranged alternately at intervals, and the first electrode region R1 and the second electrode region R2 are aligned in the direction along the winding direction DR.

[0049] In this embodiment, the case in which the first electrode layer 200A is the negative electrode and the second electrode layer 200B is the positive electrode is described as an example, but the embodiment is not limited to this. The first electrode layer 200A may be the positive electrode and the second electrode layer 200B may be the negative electrode.

[0050] The separator 110 is made of an insulating resin material. The separator 110 may contain, for example, a polyolefin resin. The separator 110 may be substantially made of a polyolefin resin. The polyolefin resin may contain, for example, at least one selected from the group consisting of polyethylene (PE) and polypropylene (PP).

[0051] The wound electrode body 10 comprises a plurality of first tabs 150A and a plurality of second tabs 150B.

[0052] One end of each of the multiple 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 multiple first tabs 150A is joined to the first connecting member 40A by ultrasonic welding or the like.

[0053] One end of each of the multiple 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 multiple second tabs 150B is joined to the second connecting member 40B described above by ultrasonic welding or the like.

[0054] Figure 7 is an unfolded view of the electrode body of Embodiment 1. Figure 8 is a cross-sectional view of the wound electrode body shown in Figure 7, viewed in the direction of the arrow VIII-VIII.

[0055] As shown in Figures 7 and 8, the separator 110 has one end 110c and the other end 110d in the winding direction, and a non-formed region R0 between the first electrode region R1 and the second electrode region R2 where no electrode layer is provided. The one end 110c constitutes the outer end in the winding state, and the other end 110d constitutes 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.

[0056] As described above, the first electrode region R1 is provided with a first electrode layer 200A. The first electrode layer 200A includes a first conductive layer 210A and a first active material layer 220A.

[0057] On the first main surface 110a and the second main surface 110b located in the first electrode region R1, the first conductive layer 210A and the first active material layer 220A are stacked in this order from the separator 110 side. That is, in the first electrode region R1, the first conductive layer 210A is provided on the first main surface 110a and the second main surface 110b, respectively, and the 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, respectively.

[0058] The first conductive layer 210A is provided, for example, by depositing a metal containing copper onto the first main surface 110a and the second main surface 110b. The first conductive layer 210A may also be a film-like member adhered to the separator 110. The first active material layer 220A is, for example, a negative electrode active material layer.

[0059] On the first main surface 110a and the second main surface 110b located in the second electrode region R2, the second conductive layer 210B and the second active material layer 220B are laminated in this order from the separator 110 side. That is, in the second electrode region R2, the second conductive layer 210B is provided on the first main surface 110a and the second main surface 110b, respectively, and the second active material layer 220B is laminated on the second conductive layer 210B on the first main surface 110a and the second conductive layer 210B on the second main surface 110b, respectively.

[0060] The second conductive layer 210B is provided, for example, by depositing a metal containing aluminum onto the first main surface 110a and the second main surface 110b. The second conductive layer 210B may be a film-like member adhered to the separator 110. The second active material layer 220B is, for example, a positive electrode active material layer.

[0061] As shown in Figures 4 and 7, when the separator 110 is wound, non-formed regions R0 are located inside the innermost electrode layer (more specifically the first electrode layer), between adjacent electrode layers (the first electrode layer and the second electrode layer) in the radial direction around the winding axis, and outside the outermost electrode layer (more specifically the first electrode layer).

[0062] This prevents the innermost electrode layers from coming into direct contact with each other, the first electrode layer 200A and the second electrode layer 200B from coming into direct contact with each other in the radial direction, and the outermost electrode layer from coming into direct contact with a component such as the case 20 located outside the wound electrode body 10.

[0063] Furthermore, the length of each region in the winding direction increases from the inside to the outside of the winding direction. The outermost first electrode layer 200A is longer in the winding direction than the second electrode layer 200B, which is located on the inner side of the winding direction following the first electrode layer 200A. Also, the second electrode layer 200B is longer in the winding direction than the first electrode layer 200A, which is located on the inside of the winding direction following the second electrode layer 200B. In other words, the second electrode layer 200B is longer in the winding direction than the innermost first electrode layer 200A.

[0064] This allows the first electrode layer 200A and the second electrode layer 200B to efficiently face each other in the radial direction centered on the winding axis. The outermost first electrode layer 200A faces the second electrode layer 200B, which is positioned on the inner circumference in the winding direction following the first electrode layer 200A, in the radial direction. The second electrode layer 200B also faces the first electrode layer 200A, which is positioned on the inner side in the winding direction following the second electrode layer 200B, in the radial direction.

[0065] Figure 9 is a magnified partial cross-sectional view of region IX of the wound electrode body shown in Figure 5. Figure 10 is a magnified partial cross-sectional view of region X of the wound electrode body shown in Figure 6.

[0066] As shown in Figures 7, 9, and 10, the wound electrode body 10 comprises a first protective section 300A, a second protective section 300B, a lower first protective section 400A, and a lower second protective section 400B. The first protective section 300A and the lower first protective section 400A protect the upper and lower ends of the first active material layer 220A in the first electrode region R1. The second protective section 300B and the lower second protective section 400B protect the upper and lower ends of the second active material layer 220B in the second electrode region R2.

[0067] The first protective part 300A has electrical insulating properties and is made of, for example, ceramic. The first protective part 300A covers the upper part of the first active material layer 220A. The first protective part 300A further covers the separator 110 between the first tab 150A and the first active material layer 220A.

[0068] The second protective part 300B has electrical insulating properties and is made of, for example, ceramic. The second protective part 300B covers the upper part of the second active material layer 220B. The second protective part 300B further covers the separator 110 between the second tab 150B and the second active material layer 220B.

[0069] The lower first protective section 400A has electrical insulating properties and is made of, for example, ceramic. The lower first protective section 400A covers the lower part of the first active material layer 220A.

[0070] The lower second protective section 400B has electrical insulating properties and is made of, for example, ceramic. The lower second protective section 400B covers the lower part of the second active material layer 220B.

[0071] As shown in Figure 9, the first conductive layer 210A has a first exposed portion 210C exposed from the first active material layer 220A on one side in the width direction D0 perpendicular to the winding direction. The width direction D0 is parallel to the first direction D1 described above. The first exposed portion 210C is provided on the first main surface 110a and the second main surface 110b.

[0072] The separator 110 has a strip-shaped main body portion 111 and a plurality of protruding pieces 112 that project from the main body portion 111 to one side in the width direction D0. The plurality of protruding pieces 112 are provided at positions corresponding to the plurality of first tabs 150A, 150B. The first exposed portion 210C described above is mainly provided on the protruding pieces 112.

[0073] In each first electrode region R1, multiple first tabs 150A are connected to the first exposed portion 210C. Specifically, multiple first tabs 150A are connected to the portion of the first exposed portion 210C that is exposed from the first protective portion 300A.

[0074] 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 the thickness direction DT, sandwiching the upper end of the separator 110 and the first exposed portion 210C. The first foil portion 151 and the second foil portion 152 are joined to each other by ultrasonic welding or the like.

[0075] As shown in Figure 10, the second conductive layer 210B has a second exposed portion 210D on one side in the width direction D0 perpendicular to the winding direction, which is exposed 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 piece 112.

[0076] In each second electrode region R2, multiple second tabs 150B are connected to the second exposed portion 210D. Specifically, multiple second tabs 150B are connected to the portion of the second exposed portion 210D that is exposed from the second protective portion 300B.

[0077] 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 the thickness direction DT, sandwiching the upper end of the separator 110 and the second exposed portion 210D. The third foil portion 153 and the fourth foil portion 154 are joined to each other by ultrasonic welding or the like.

[0078] As described above, the wound electrode body 10 according to this embodiment 1 is constructed by winding a separator 110 in which a first electrode region R1 and a second electrode region R2, each provided with an electrode layer, are alternately arranged with a gap between them. This reduces the number of parts compared to a configuration in which a positive electrode sheet and a negative electrode sheet are wound with a separator interposed between them.

[0079] In Embodiment 1, the case in which the first active material layer 220A and the second active material layer 220B are the same size is illustrated, but the invention is not limited to this. The size of the first active material layer 220A may be larger than the size of the second active material layer 220B. In this case, when the first active material layer 220A is used as the negative electrode, the deposition of dendrites from the second active material layer 220B can be suppressed.

[0080] (Embodiment 2) Figure 11 is a cross-sectional view of the wound electrode body according to Embodiment 2. Figure 12 is a cross-sectional view of the wound electrode body according to Embodiment 2 in an unfolded state. Note that Figure 11 corresponds to a schematic cross-sectional view of the wound electrode body shown in Figure 3 of Embodiment 1, viewed in the direction of the arrow VI-VI. Figure 12 corresponds to a cross-sectional view of the wound electrode body shown in Figure 7 of Embodiment 1, viewed in the direction of the arrow VIII-VIII. The wound electrode body 10X according to Embodiment 2 will be described with reference to Figures 11 and 12.

[0081] As shown in Figures 11 and 12, the wound electrode body 10X according to Embodiment 2 differs from the wound electrode body 10 according to Embodiment 1 mainly in the arrangement of the first electrode layer 200A and the second electrode layer 200B. Also, as will be described later using Figures 13 and 14, the configuration of the first tab 150A and the second tab 150B is different. The other configurations are almost the same.

[0082] In Embodiment 2, the first electrode layer 200A and the second electrode layer 200B are provided in the first electrode region R1 and the second electrode region R2, respectively, with the separator 110 sandwiched between them.

[0083] Specifically, the first main surface 110a of the separator 110 located in the first electrode region R1 and the first main surface 110a of the separator 110 located in the second electrode region R2 are each laminated with a first conductive layer 210A and a first active material layer 220A in that order from the separator 110 side. The second main surface 110b located in the first electrode region R1 and the second main surface 110b located in the second electrode region R2 are each laminated with a second conductive layer 210B and a second active material layer 220B in that order from the separator 110 side.

[0084] Furthermore, the size of the first active material layer 220A may 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 may be located above the upper end of the second active material layer 220B in the width direction D0. Also, the lower end of the first active material layer 220A in the width direction D0 may be located below the lower end of the second active material layer 220B in the width direction D0.

[0085] Figures 13 and 14 are partial cross-sectional views showing the installation configuration of the first tab and the second tab in the wound electrode body according to Embodiment 2. Figure 13 corresponds to Figure 9 according to Embodiment 1, and specifically corresponds to a partial cross-sectional view showing an enlarged view of region XI of the wound electrode body shown in Figure 5. Figure 14 corresponds to Figure 10 according to Embodiment 1, and specifically corresponds to a partial cross-sectional view showing an enlarged view of region X of the wound electrode body shown in Figure 6.

[0086] As shown in Figures 13 and 14, in Embodiment 2, in the first electrode region R1 and the second electrode region R2, the upper ends of the first active material layer 220A and the second active material layer 220B are covered by the first protective part 300A and the second protective part 300B, respectively. Similarly, although not shown here, in the first electrode region R1 and the second electrode region R2, the lower ends of the first active material layer 220A and the second active material layer 220B are covered by the lower first protective part 400A and the lower second protective part 400B described above, respectively.

[0087] As shown in Figure 13, 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 in the width direction D0 perpendicular 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 in the width direction D0.

[0088] 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 made of, for example, a single plate-shaped metal foil. However, as long as the first tab 150A is made of a plate shape, it may be made of multiple metal foils laminated together.

[0089] As shown in Figure 14, 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 in the width direction D0 perpendicular 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 in the width direction D0.

[0090] 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 bonded to the portion of the second exposed portion 210D that is exposed from the second protective portion 300B. The second tab 150A is made of, for example, a single plate-shaped metal foil. However, as long as the second tab 150A is made of a plate shape, it may be made of multiple metal foils laminated together.

[0091] Even when configured as described above, the wound electrode body 10X is formed by winding a separator 110 in which a first electrode region R1 and a second electrode region R2, each provided with an electrode layer, are alternately arranged with a gap between them. For this reason, the wound electrode body 10X according to Embodiment 2 can obtain substantially the same effects as the wound electrode body 10 according to Embodiment 1.

[0092] 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]

[0093] 1 Battery, 10,10X wound electrode body, 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, 72 Peripheral insulating part, 73 Bottom insulating part, 80 Fuse protection part, 110 separator, 110a first main surface, 110b second main surface, 110c one end, 110d other end, 111 main body part, 112 protruding piece part, 150A first tab, 150B second tab, 151 first foil part, 152 second foil part, 153 third foil part, 154 fourth foil part, 200A first electrode layer, 200B second electrode layer, 210A first conductive layer, 210B second conductive layer, 210C first exposed part, 210D second exposed part, 220A first active material layer, 220B second active material layer, 300A first protection part, 300B second protection part, 400A lower first protection part, 400B lower second protection part, R0 non-formed region, R1 first electrode region, R2 second electrode region.

Claims

1. The device comprises a separator in which a first electrode region and a second electrode region, each provided with an electrode layer, are alternately arranged with a gap between them. A wound electrode body in which the separator is wound such that the direction in which the first electrode region and the second electrode region are aligned is along the winding direction.

2. A first electrode layer is provided in the first electrode region. The aforementioned second electrode region is provided with a second electrode layer having a different polarity from the aforementioned first electrode layer. 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 stacked in this order from the separator side. The wound electrode body according to claim 1, wherein the second conductive layer and the second active material layer are laminated in this order from the separator side on each of the first main surface and the second main surface located in the second electrode region.

3. The first conductive layer has a first exposed portion exposed from the first active material layer on one side in the width direction perpendicular to the winding direction, The second conductive layer has a second exposed portion on one side in the width direction that is exposed from the second active material layer, Multiple first tabs connected to the first exposed portion, The wound electrode body according to claim 2, further comprising a plurality of second tabs connected to the second exposed portion.

4. Each of the first electrode region and the second electrode region is provided with a first electrode layer and a second electrode layer having a different polarity from the first electrode layer, separated by 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 the first main surface located in the first electrode region and the first main surface located in the second electrode region, the first conductive layer and the first active material layer are laminated in this order from the separator side. The wound electrode body according to claim 1, wherein the second conductive layer and the second active material layer are laminated in this order 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.

5. In the first electrode region, the first conductive layer has a first exposed portion exposed from the first active material layer on one side in the width direction perpendicular to the winding direction, In the second electrode region, the second conductive layer has a second exposed portion on one side in the width direction that is exposed from the second active material layer. In the first electrode region, a plurality of first tabs are connected to the first exposed portion of the first conductive layer but are not connected to the second conductive layer, The wound electrode body according to claim 4, further comprising a plurality of second tabs in the second electrode region that are not connected to the first conductive layer 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, wherein each of the first electrode region and the second electrode region has a length along the winding direction that increases from the inside to the outside in the winding direction.

7. The separator has a non-formed region where the electrode layer is not provided, at one end in the winding direction and the other end in the winding direction, and between the first electrode region and the second electrode region. The wound electrode body according to any one of claims 1 to 5, wherein the non-formed regions are arranged inside the innermost electrode layer, between adjacent electrode layers in the radial direction around the winding axis, and outside the outermost electrode layer.

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