Current collector and battery

Abstract

This reduces the energy required for bonding between the conductive layer and the tab. [Solution] The current collector 100A comprises a support layer 110, a first conductive layer 120, and a tab 140. The support layer 110 is made of an electrically insulating resin composition. The first conductive layer 120 is laminated on the support layer 110. The tab 140 includes a first fixing portion 141 and a first extension portion 142. The first fixing portion 141 and the first extension portion 142 are made of metal. The first fixing portion 141 and the first extension portion 142 are integrally formed. The first fixing portion 141 extends along the first conductive layer 120. The first extension portion 142 extends from the first fixing portion 141. The first fixing portion 141 includes a plurality of first protrusions 141a. The first fixing portion 141 is fixed to the first conductive layer 120 by having multiple first protrusions 141a that are embedded in the first conductive layer 120.

Description

Technical Field

[0001] The present disclosure relates to a current collector and a battery.

Background Art

[0002] JP-T 2024-510696 discloses an electrode plate. The electrode plate includes a current collector, an active material layer, and an electrical connection member. The current collector includes a support layer and a conductive layer. The conductive layer is provided on one surface of the support layer. In the current collector, the conductive layer serves as a conductor and a current collector, and provides electrons for the active material layer. The electrical connection member and the current collector are welded and connected at the edge of the current collector.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally, the conductive layer and the tab-shaped electrical connection member are joined to each other by welding. Welding requires heating. Therefore, relatively high energy is required for joining the conductive layer and the electrical connection member.

[0005] The present disclosure has been made in view of the above problems, and an object thereof is to provide an electrode body and a battery capable of reducing the energy required for joining a conductive layer and a tab.

Means for Solving the Problems

[0006] A current collector according to a certain aspect of the present disclosure comprises a support layer, a first conductive layer, and a tab. The support layer is made of an electrically insulating resin composition. The first conductive layer is laminated on the support layer. The tab includes a first fixed portion and a first extension. The first fixed portion and the first extension are made of metal. The first fixed portion and the first extension are integrally formed. The first fixed portion extends along the first conductive layer. The first extension extends from the first fixed portion. The first fixed portion includes a plurality of first projections. The first fixed portion is fixed to the first conductive layer by the plurality of first projections penetrating the first conductive layer.

[0007] A battery according to a certain aspect of this disclosure comprises an electrode body and an external terminal. The electrode body includes a first electrode, a second electrode, and a separator. The first electrode includes a current collector and an active material layer. The current collector includes a support layer, a first conductive layer, and a tab. The support layer is made of an electrically insulating resin composition. The first conductive layer is laminated on the support layer. The tab includes a first fixed portion and a first extension. The first fixed portion and the first extension are made of metal. The first fixed portion and the first extension are integrally formed. The first fixed portion extends along the first conductive layer. The first extension extends from the first fixed portion. The first fixed portion includes a plurality of first protrusions. The first fixed portion is fixed to the first conductive layer by the plurality of first protrusions being embedded in the first conductive layer. The active material layer is laminated on the first conductive layer. The separator is laminated in the active material layer. The second electrode is laminated in the active material layer via the separator. The external terminals are electrically connected to the tabs. [Effects of the Invention]

[0008] According to this disclosure, the energy required for bonding the conductive layer and the tab can be reduced. [Brief explanation of the drawing]

[0009] [Figure 1] This is a cross-sectional view showing a battery according to one embodiment. [Figure 2] This is a cross-sectional view of the electrode body in Figure 1, taken in the direction of the arrow line II-II. [Figure 3]This is a cross-sectional view of the electrode body in Figure 1, taken in the direction of the arrow III-III. [Figure 4] This is a schematic cross-sectional view of the electrode body in Figure 1, partially viewed in the direction of the IV-IV arrow. [Figure 5] This is a diagram of the first electrode. [Figure 6] This is a schematic cross-sectional view showing a partially magnified view of the first electrode. [Modes for carrying out the invention]

[0010] Hereinafter, a battery and a current collector according to one embodiment of the present disclosure will be described with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and their descriptions will not be repeated.

[0011] Figure 1 is a cross-sectional view showing a battery according to one embodiment. The battery 1 shown in Figure 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 mounted on an electric vehicle.

[0012] As shown in Figure 1, a battery 1 according to one embodiment of the present disclosure comprises an electrode body 10, a case 20, a first external terminal 30A, a second external terminal 30B, a first connecting member 40A, and a second connecting member 40B. First, the components of the battery 1 other than the electrode body 10 will be described.

[0013] Case 20 is conductive. The conductive portion of Case 20 is made of a metal such as aluminum. Case 20 houses the electrode body 10. Case 20 also houses an electrolyte (not shown).

[0014] 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.

[0015] The lid 22 is joined to the peripheral wall 21b by welding or the like so as to close the opening of the peripheral wall 21b. The lid 22 has a first connection hole 22a and a second connection hole 22b formed therein.

[0016] The first external terminal 30A and the second external terminal 30B are provided so as to be exposed outside the battery 1. The first connection member 40A and the second connection member 40B have conductivity. At least a part of the first connection member 40A and the second connection member 40B is disposed inside the case 20.

[0017] The first external terminal 30A or the first connection member 40A is inserted into the first connection hole 22a. The first external terminal 30A is electrically connected to the first connection member 40A. Specifically, the first external terminal 30A and the first connection member 40A are joined to each other. The first connection member 40A is joined to the electrode body 10. Thereby, the first external terminal 30A is electrically connected to the electrode body 10.

[0018] The second external terminal 30B or the second connection member 40B is inserted into the second connection hole 22b. The second external terminal 30B is electrically connected to the second connection member 40B. Specifically, the second external terminal 30B and the second connection member 40B are joined to each other. The second connection member 40B is joined to the electrode body 10. Thereby, the second external terminal 30B is electrically connected to the electrode body 10.

[0019] In this embodiment, the first external terminal 30A is a positive terminal and the second external terminal 30B is a negative terminal. The first external terminal 30A and the second external terminal 30B are arranged side by side in the second direction D2. The second direction D2 is a direction orthogonal to the first direction D1.

[0020] Next, the electrode body 10 will be described. The battery 1 according to this embodiment includes a plurality of electrode bodies 10. The battery 1 typically includes two electrode bodies 10. These electrode bodies 10 are arranged side by side in the third direction D3. The third direction D3 is a direction orthogonal to both the first direction D1 and the second direction D2.

[0021] In the following, one electrode body 10 out of a plurality of electrode bodies 10 will be described. Note that each of the plurality of electrode bodies 10 may have the configuration shown below.

[0022] FIG. 2 is a cross-sectional view of the electrode body in FIG. 1 as seen in the direction of the arrow of line II-II. FIG. 3 is a cross-sectional view of the electrode body in FIG. 1 as seen in the direction of the arrow of line III-III. FIG. 4 is a schematic cross-sectional view of the electrode body in FIG. 1 partially seen in the direction of the arrow of line IV-IV. As shown in FIGS. 1 to 4, the electrode body 10 includes a first electrode 11A, a second electrode 11B, and a separator 12. The electrode body 10 is wound such that the first electrode 11A, the second electrode 11B, and the separator 12 surround the periphery of the winding axis Z. Thus, in the present embodiment, the electrode body 10 is a so-called wound electrode body. However, the electrode body 10 may be a laminated electrode body in which the first electrode 11A, the second electrode 11B, and the separator 12 are laminated in one direction (for example, the third direction D3). Note that in FIGS. 2 to 4, the separator 12 is schematically shown by a broken line.

[0023] The first electrode 11A and the second electrode 11B have a sheet-like outer shape. The electrode body 10 is composed of a group of electrode plates in which the first electrode 11A and the second electrode 11B are wound via one or more separators 12.

[0024] In the present embodiment, the first electrode 11A is a positive electrode and the second electrode 11B is a negative electrode. However, the first electrode 11A may be a negative electrode and the second electrode 11B may be a positive electrode.

[0025] The separator 12 is provided between the first electrode 11A and the second electrode 11B. The separator 12 allows ions to pass between the first electrode 11A and the second electrode 11B while separating the first electrode 11A and the second electrode 11B. The ions are, for example, lithium ions. The separator 12 has electrical insulation.

[0026] Of the first electrode 11A, the second electrode 11B, and the separator 12, the separator 12 is located on the innermost side with respect to the winding axis Z. Also, of the first electrode 11A, the second electrode 11B, and the separator 12, the separator 12 is located on the outermost side with respect to the winding axis Z. The outer edge of the separator 12 in the winding direction DR is fixed by a tape member 13 placed on the outer surface of the separator 12.

[0027] The separator 12 may contain, for example, a polyolefin resin. The separator 12 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).

[0028] Figure 5 is an unfolded view of the first electrode. That is, Figure 5 shows the state of the first electrode 11A before it is wound. Figure 6 is a schematic cross-sectional view showing a partially enlarged view of the first electrode. Note that the cross-sectional view in Figure 6 is illustrated in the same way as in Figure 3.

[0029] As shown in Figures 3 to 6, the first electrode 11A includes a current collector 100A, a first active material layer 200A, a first protective part 400, and a second protective part 500.

[0030] The current collector 100A includes a support layer 110, a first conductive layer 120, a second conductive layer 130, and a plurality of tabs 140.

[0031] The support layer 110 is made of an electrically insulating resin composition. Therefore, the first current collector 100A is a composite current collector made of a conductive member and an electrically insulating member. As a result, the first current collector 100A is lighter compared to the case where the first current collector 100A is made entirely of metal, and the overall safety of the battery 1 is enhanced.

[0032] The support layer 110 is made of a resin composition containing, for example, a polyamide resin, a polyester resin, or a polyolefin resin. To increase rigidity, it is preferable that the support layer 110 is made of a resin composition containing a polyester resin. It is even more preferable that the support layer 110 is substantially made of a polyester resin. The polyester resin may be, for example, polyethylene terephthalate. This makes it possible to increase the rigidity of the first current collector 100A while maintaining the electrical insulation properties of the support layer 110. Consequently, the support layer 110 can be made relatively thin.

[0033] The orthogonal direction DO, which is perpendicular to the thickness direction DT of the support layer 110, is approximately parallel to the first direction D1. That is, the support layer 110 extends approximately parallel to the first direction D1.

[0034] The thickness of the support layer 110 is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less, in order to reduce the overall thickness of the electrode body 10. The thickness of the support layer 110 is not particularly limited as long as it has the desired rigidity. The thickness of the support layer 110 may be, for example, 2 μm or more.

[0035] The first conductive layer 120 is laminated on the support layer 110. The first conductive layer 120 is provided on one surface of the support layer 110. The first conductive layer 120 is provided over the entire surface of the support layer 110.

[0036] In this embodiment, the first conductive layer 120 is located on the side of the winding axis Z when viewed from the support layer 110. However, the first conductive layer 120 may be located on the side opposite to the winding axis Z when viewed from the support layer 110.

[0037] The second conductive layer 130 is located on the opposite side from the first conductive layer 120 when viewed from the support layer 110. The second conductive layer 130 is laminated on the support layer 110. That is, the second conductive layer 130 is provided on the other side of the support layer 110. The second conductive layer 130 is provided over the entire other side.

[0038] The thickness of the first conductive layer 120 and the thickness of the second conductive layer 130 are thinner than the thickness of the support layer 110. The thickness of the first conductive layer 120 and the second conductive layer 130 are, for example, 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less, in order to reduce the overall thickness of the electrode body 10. The thickness of the first conductive layer 120 and the second conductive layer 130 may be, for example, 0.1 μm or more, in order to prevent the electrical resistance of the first conductive layer 120 and the second conductive layer 130 from becoming too high. Note that if the thickness of the first conductive layer 120 and the second conductive layer 130 are 5 μm or less, it is difficult to directly weld the first conductive layer 120 and the second conductive layer 130 to each other or to directly join them to each other by ultrasonic welding.

[0039] The method for forming the first conductive layer 120 and the second conductive layer 130 is not particularly limited. Typically, the first conductive layer 120 and the second conductive layer 130 may be provided on the support layer 110 by a vapor deposition method or the like. The first conductive layer 120 and the second conductive layer 130 may be composed of metal films. In this case, the first conductive layer 120 and the second conductive layer 130 may be bonded to the support layer 110 via a resin adhesive.

[0040] Furthermore, the first conductive layer 120 and the second conductive layer 130 are typically made of a metal containing aluminum. As a result, the first current collector 100A, which includes the first conductive layer 120 and the second conductive layer 130, can be suitably used as a positive electrode current collector. The first current collector 100A may also be a negative electrode current collector, and the first conductive layer 120 and the second conductive layer 130 may be made of a metal containing copper.

[0041] As shown in Figure 5, the multiple tabs 140 are aligned in the winding direction DR of the electrode body 10. The multiple tabs 140 are spaced apart from each other.

[0042] As shown in Figure 3, the multiple tabs 140 are arranged in the third direction D3. The multiple tabs 140 are joined to each other by ultrasonic bonding or the like. Furthermore, as shown in Figure 1, the multiple tabs 140 are joined to the first connecting member 40A by ultrasonic bonding or the like. As a result, the first external terminal 30A is electrically connected to the tabs 140. The configuration of each of the multiple tabs 140 will be described below.

[0043] As shown in Figure 6, the tab 140 includes a first fixing portion 141, a first extension portion 142, a second fixing portion 143, and a second extension portion 144.

[0044] The first fixing portion 141 and the first extension portion 142 are made of metal. Typically, the first fixing portion 141 and the first extension portion 142 are made of a metal containing aluminum or copper. The first fixing portion 141 and the first extension portion 142 are made of, for example, a metal film. The first fixing portion 141 and the first extension portion 142 are integrally formed.

[0045] The first fixed portion 141 extends along the first conductive layer 120. That is, the first fixed portion 141 extends along the orthogonal direction DO on the first conductive layer 120.

[0046] The first fixing portion 141 includes a plurality of first projections 141a, a first surface 141b, a second surface 141c, and a plurality of first recesses 141d.

[0047] The first fixing portion 141 is fixed to the first conductive layer 120 by the fact that a plurality of first protrusions 141a are embedded in the first conductive layer 120. To more firmly fix the first fixing portion 141 and the first conductive layer 120, a resin adhesive may be provided between the first fixing portion 141 and the first conductive layer 120. However, in order to make the current collector 100A less expensive, the resin adhesive may not be provided. In addition, the first fixing portion 141 and the first conductive layer 120 may be joined to each other by ultrasonic bonding. However, in order to make the current collector 100A less expensive, the first fixing portion 141 and the first conductive layer 120 may not be joined to each other by ultrasonic bonding.

[0048] Multiple first protrusions 141a penetrate the first conductive layer 120. Multiple first protrusions 141a further penetrate the support layer 110. Multiple first protrusions 141a further penetrate the support layer 110. Multiple first protrusions 141a may also penetrate the support layer 110 by fitting into multiple through holes provided in the support layer 110 beforehand.

[0049] The first surface 141b is oriented toward the first conductive layer 120. The first surface 141b is in contact with the first conductive layer 120. Multiple first protrusions 141a are provided on the first surface 141b.

[0050] The second surface 141c is the opposite surface to the first surface 141b. Multiple first recesses 141d are provided on the second surface 141c. The multiple first recesses 141d are arranged in a one-to-one correspondence with the multiple first protrusions 141a.

[0051] The first extension portion 142 extends from the first fixed portion 141. The extension direction DE of the first extension portion 142 is substantially parallel to the orthogonal direction DO (first direction D1). In the thickness direction DT, the first extension portion 142 is not aligned with the support layer 110.

[0052] The second fixing portion 143 and the second extension portion 144 are made of metal. The second fixing portion 143 and the second extension portion 144 are typically made of a metal containing aluminum or copper. The second fixing portion 143 and the second extension portion 144 are made of, for example, a metal film. The second fixing portion 143 and the second extension portion 144 are integrally formed.

[0053] The second fixing portion 143 extends along the second conductive layer 130. That is, the second fixing portion 143 extends along the orthogonal direction DO on the second conductive layer 130.

[0054] The second fixing portion 143 includes a plurality of second protrusions 143a, a third surface 143b, a fourth surface 143c, and a plurality of second recesses 143d.

[0055] The second fixing portion 143 is fixed to the second conductive layer 130 by the fact that multiple second protrusions 143a are embedded in the second conductive layer 130. To more firmly fix the second fixing portion 143 to the second conductive layer 130, a resin adhesive may be provided between the second fixing portion 143 and the second conductive layer 130. However, in order to make the current collector 100A less expensive, the resin adhesive may not be provided. Alternatively, the second fixing portion 143 and the second conductive layer 130 may be joined to each other by ultrasonic bonding. The anchoring effect of ultrasonic bonding can further firmly fix the second fixing portion 143 and the second conductive layer 130 to each other. However, in order to make the current collector 100A less expensive, the second fixing portion 143 and the second conductive layer 130 may not be joined to each other by ultrasonic bonding.

[0056] Multiple second protrusions 143a penetrate the second conductive layer 130. Multiple second protrusions 143a further penetrate the support layer 110. Multiple second protrusions 143a further penetrate the support layer 110. Multiple second protrusions 143a may also penetrate the support layer 110 by fitting into through holes provided in the support layer 110 beforehand.

[0057] The third surface 143b is oriented toward the second conductive layer 130. Multiple second protrusions 143a are provided on the third surface 143b.

[0058] The fourth surface 143c is the opposite surface to the third surface 143b. Multiple second recesses 143d are provided on the fourth surface 143c. The multiple second recesses 143d are arranged in a one-to-one correspondence with the multiple second protrusions 143a.

[0059] The second extension 144 extends from the second fixed portion 143. The direction in which the second extension 144 extends is substantially parallel to the extension direction DE. The second extension 144 as a whole extends along the first extension 142. The second extension 144 is continuous with the first extension 142 at the end 144a opposite to the second fixed portion 143. The second extension 144 is formed integrally with the first extension 142.

[0060] In other words, in this embodiment, the tab 140 as a whole consists of a single metal film that is folded back at its end 144a. The first extension 142 and the second extension 144 are joined to the first connecting member 40A.

[0061] The thickness of the tab 140 (the thickness of the first fixing portion 141, the first extension portion 142, the second fixing portion 143, and the second extension portion 144) is greater than the thickness of the first conductive layer 120 and the second conductive layer 130. The thickness of the tab 140 is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The thickness of the tab 140 is not particularly limited as long as it has the desired rigidity. The thickness of the tab 140 may be, for example, 2 μm or more.

[0062] The first active material layer 200A is laminated on the first conductive layer 120 and the second conductive layer 130. The first active material layer 200A is a positive electrode active material layer, but it may also be a negative electrode active material layer. The first active material layer 200A is separated from the tab 140.

[0063] The separator 12 is stacked on the first active material layer 200A in the radial direction centered on the winding axis Z (see Figure 3, etc.).

[0064] The first protective portion 400 is made of an electrically insulating ceramic. The first protective portion 400 covers a portion of the first active material layer 200A, which is laminated on the first conductive layer 120, on the DE side in the extension direction. The first protective portion 400 covers the entire surface of the first conductive layer 120 between the first active material layer 200A and the first fixing portion 141. The first protective portion 400 is also partially positioned between the first conductive layer 120 and the first fixing portion 141.

[0065] The second protective portion 500 is made of an electrically insulating ceramic. The second protective portion 500 covers a portion of the first active material layer 200A, which is laminated on the second conductive layer 130, on the DE side in the extension direction. The second protective portion 500 covers the entire surface of the second conductive layer 130 between the first active material layer 200A and the second fixing portion 143. The second protective portion 500 is also partially positioned between the second conductive layer 130 and the second fixing portion 143.

[0066] As shown in Figures 2 to 4, the second electrode 11B is laminated on the first active material layer 200A via a separator 12 in the radial direction. In this embodiment, the electrode body 10 includes multiple separators 12, but it may also include a single separator 12.

[0067] The second electrode 11B includes a second current collector 100B and a second active material layer 200B. The second current collector 100B includes a conductive support portion 170 and a plurality of second tab portions 180 (see Figure 4). The conductive support portion 170 extends along the orthogonal direction DO (first direction D1). The plurality of second tab portions 180 extend from the upper end of the conductive support portion 170. The plurality of second tab portions 180 are joined to each other by ultrasonic welding and are also joined to the second connecting member 40B (see Figure 1).

[0068] The multiple second tab portions 180 and conductive support portions 170 are made of an integral material, for example, a metal film. In this embodiment, the multiple second tab portions 180 and conductive support portions 170 are made of a metal including copper, for example. This allows the second current collector 100B to be suitably used as a negative electrode current collector. If the first current collector 100A is a negative electrode current collector and the second current collector 100B is a positive electrode current collector, the multiple second tab portions 180 and conductive support portions 170 may be made of a metal including aluminum.

[0069] The second active material layer 200B is laminated on both sides of the conductive support portion 170 of the second current collector 100B. In this embodiment, the second electrode 11B is the negative electrode. Therefore, the second active material layer 200B is the negative electrode active material layer. The second active material layer 200B may also be the positive electrode active material layer.

[0070] As described above, in the current collector 100A according to one embodiment of the present disclosure, the first fixing portion 141 is fixed to the first conductive layer 120 by the fact that a plurality of first protrusions 141a are inserted into the first conductive layer 120.

[0071] According to the above configuration, since the multiple first protrusions 141a are mechanically bonded to the first conductive layer 120, the first conductive layer 120 and the first fixing part 141 can be fixed to each other without necessarily requiring welding or ultrasonic bonding. Therefore, it is possible to provide a current collector 100A and a battery 1 equipped therewith in which the energy required for bonding the first conductive layer 120 and the tab 140 is reduced.

[0072] In this embodiment, the first fixing portion 141 further includes a first surface 141b, a second surface 141c, and a plurality of first recesses 141d. The first surface 141b faces the first conductive layer 120. The plurality of first protrusions 141a are provided on the first surface 141b. The second surface 141c is the opposite surface to the first surface 141b. The plurality of first recesses 141d are provided on the second surface 141c. The plurality of first recesses 141d are arranged in a one-to-one correspondence with the plurality of first protrusions 141a.

[0073] According to the above configuration, multiple first recesses 141d and multiple first protrusions 141a can be formed by embossing. Consequently, multiple first protrusions 141a can be formed on the first fixing portion 141 relatively easily.

[0074] Furthermore, in this embodiment, the multiple first protrusions 141a penetrate the first conductive layer 120. The multiple first protrusions 141a also penetrate the support layer 110.

[0075] According to the above configuration, the tab 140 can also be fixed to the support layer 110, and can be more firmly fixed to the first conductive layer 120.

[0076] In this embodiment, the current collector 100A further comprises a second conductive layer 130. The second conductive layer 130 is located on the opposite side from the first conductive layer 120 when viewed from the support layer 110. The second conductive layer 130 is laminated on the support layer 110. The tab 140 further comprises a second fixing portion 143 and a second extension portion 144. The second fixing portion 143 and the second extension portion 144 are made of metal. The second fixing portion 143 and the second extension portion 144 are integrally formed. The second fixing portion 143 extends along the second conductive layer 130. The second extension portion 144 extends from the second fixing portion 143. The second fixing portion 143 includes a plurality of second projections 143a, a third surface 143b, a fourth surface 143c, and a plurality of second recesses 143d. The second fixing portion 143 is fixed to the second conductive layer 130 by the fact that multiple second projections 143a are embedded in the second conductive layer 130. The third surface 143b faces the second conductive layer 130. Multiple second projections 143a are provided on the third surface 143b. The fourth surface 143c is the opposite surface of the third surface 143b. Multiple second recesses 143d are provided on the fourth surface 143c. Multiple second recesses 143d are arranged in a one-to-one correspondence with multiple second projections 143a. Multiple first projections 141a penetrate the first conductive layer 120. Multiple first projections 141a are further embedded in the support layer 110. Multiple second projections 143a penetrate the second conductive layer 130. Multiple second projections 143a further penetrate the support layer 110. The second extension 144 is continuous with the first extension 142 at the end 144a opposite to the second fixing portion 143. The second extension 144 is formed integrally with the first extension 142.

[0077] According to the above configuration, even when conductive layers are present on both sides of the support layer 110, multiple second protrusions 143a are mechanically bonded to the second conductive layer 130. Therefore, the second conductive layer 130 and the second fixing part 143 can be fixed to each other without necessarily requiring welding or ultrasonic bonding. Thus, the energy required to bond the second conductive layer 130 and the tab 140 can be reduced. Furthermore, according to the above configuration, multiple second protrusions 143a can be formed together with multiple second recesses 143d by embossing. Consequently, the second protrusions 143a can be formed on the second fixing part 143 relatively easily. Moreover, since the second extension 144 is continuous with the first extension 142 and integrally formed with the first extension 142, the tab 140 as a whole can be formed from a single component. Consequently, an increase in the number of components constituting the current collector 100A can be suppressed, and a more inexpensive current collector 100A and a battery 1 equipped therewith can be provided.

[0078] In the above-described embodiment, the combinatable configurations may be combined with each other.

[0079] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of this disclosure is indicated by the claims rather than the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended. [Explanation of symbols]

[0080] 1 Battery, 10 Electrode body, 11A First electrode, 11B Second electrode, 12 Separator, 13 Tape member, 20 Case, 21 Case body, 21a Bottom wall, 21b Peripheral wall, 22 Lid, 22a First connecting hole, 22b Second connecting hole, 30A First external terminal, 30B Second external terminal, 40A First connecting member, 40B Second connecting member, 100A First current collector, 100B Second current collector, 110 Support layer, 120 First conductive layer, 130 Second conductive layer, 140 Tab, 141 First fixing part, 141a First projection, 141b First surface, 141c Second surface, 141d First recess, 142 First extension, 143 Second fixing part, 143a Second projection, 143b Third surface, 143c Fourth surface, 143d second recess, 144 second extension, 144a end, 170 conductive support, 180 second tab, 200A first active material layer, 200B second active material layer, 400 first protective part, 500 second protective part, D1 first direction, D2 second direction, D3 third direction, DE extension direction, DO orthogonal direction, DR winding direction, DT thickness direction, Z winding axis.

Claims

1. It is a current collector, Supporting layer, First conductive layer and Equipped with tabs, The support layer is made of an electrically insulating resin composition. The first conductive layer is laminated on the support layer, The tab includes a first fixing portion and a first extension portion, The first fixed portion and the first extension portion are made of metal and are integrally formed. The first fixed portion extends along the first conductive layer, The first extension extends from the first fixed portion, The first fixing portion includes a plurality of first protrusions, The first fixed portion is a current collector that is fixed to the first conductive layer by the plurality of first protrusions being inserted into the first conductive layer.

2. The first fixing portion further includes a first surface, a second surface, and a plurality of first recesses, The first surface is oriented toward the first conductive layer, The plurality of first protrusions are provided on the first surface, The second surface is the opposite surface of the first surface, The current collector according to claim 1, wherein the plurality of first recesses are provided on the second surface and are arranged in a one-to-one correspondence with the plurality of first protrusions.

3. The plurality of first protrusions penetrate the first conductive layer, The current collector according to claim 1 or claim 2, wherein the plurality of first protrusions are further inserted into the support layer.

4. Further comprising a second conductive layer, The second conductive layer is located on the opposite side from the first conductive layer when viewed from the support layer, and is laminated on the support layer. The tab further includes a second fixing portion and a second extension portion, The second fixing portion and the second extension portion are made of metal and are integrally formed. The second fixing portion extends along the second conductive layer, The second extension extends from the second fixed portion, The second fixing portion includes a plurality of second protrusions, a third surface, a fourth surface, and a plurality of second recesses. The second fixing portion is fixed to the second conductive layer by the fact that the plurality of second protrusions are embedded in the second conductive layer. The third surface is oriented toward the second conductive layer, The plurality of second protrusions are provided on the third surface, The fourth surface is the opposite surface of the third surface, The plurality of second recesses are provided on the fourth surface and are arranged in a one-to-one correspondence with the plurality of second protrusions. The plurality of first protrusions penetrate the first conductive layer, The aforementioned plurality of first protrusions are further embedded in the support layer, The plurality of second protrusions penetrate the second conductive layer, The aforementioned plurality of second protrusions are further embedded in the support layer, The current collector according to claim 2, wherein the second extension is continuous with the first extension at the end opposite to the second fixed portion and is integrally formed with the first extension.

5. It is a battery, Electrode body and Equipped with external terminals, The electrode body includes a first electrode, a second electrode, and a separator. The first electrode comprises a current collector and an active material layer. The current collector includes a support layer, a first conductive layer, and a tab. The support layer is made of an electrically insulating resin composition. The first conductive layer is laminated on the support layer, The tab includes a first fixing portion and a first extension portion, The first fixed portion and the first extension portion are made of metal and are integrally formed. The first fixed portion extends along the first conductive layer, The first extension extends from the first fixed portion, The first fixing portion includes a plurality of first protrusions, The first fixing portion is fixed to the first conductive layer by the fact that the plurality of first protrusions are embedded in the first conductive layer. The active material layer is laminated on the first conductive layer, The separator is laminated on the active material layer, The second electrode is laminated on the active material layer via the separator, The external terminal is electrically connected to the tab and is a battery.

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