Current collector and battery

Abstract

The invention provides a current collector and a battery. The current collector includes a support layer, a first conductive layer, and a lug portion. The support layer is composed of a resin composition having electrical insulating properties. The first conductive layer is laminated on the support layer. The lug portion is configured from a film-like member. The lug portion includes a lug body portion and a first heat dissipation portion. The lug body portion is bonded to the first conductive layer by ultrasonic welding. The lug body portion extends away from the first conductive layer. The first heat dissipation part is shorter than the lug body part in the extending direction of the lug body part. The first heat dissipation part is not bonded to the first conductive layer by ultrasonic welding.

Description

TECHNICAL FIELD

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

[0002] Japanese Laid-Open Patent Publication No. 2024-510696 discloses a conventional 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 to one surface of the support layer. In the current collector, the conductive layer functions as a conductor and a current collector, and supplies electrons to the active material layer. The electrical connection member and the current collector are welded at an edge of the current collector. This welded region is called a relay welding region. SUMMARY

[0003] In the relay welding region, the electrical resistance value is relatively high. Therefore, when the current collector is energized, relatively large heat is generated in this region. On the other hand, when a shape or a member for suppressing this heat is added, the manufacturing cost of the current collector can increase, and the weight can increase.

[0004] The present disclosure was achieved in view of the above-described problems, and aims to provide a current collector that suppresses heat generation when energized while suppressing an increase in manufacturing cost and weight, and a battery that includes the same.

[0005] The current collector according to an aspect of the present disclosure includes a support layer, a first conductive layer, and a tab portion. The support layer is composed of a resin composition having electrical insulation. The first conductive layer is laminated to the support layer. The tab portion is composed of a film-shaped member. The tab portion includes a tab body portion and a first heat dissipation portion. The tab body portion is joined to the first conductive layer by ultrasonic welding. The tab body portion extends away from the first conductive layer. The first heat dissipation portion is shorter than the tab body portion in the extending direction of the tab body portion. The first heat dissipation portion is not joined to the first conductive layer by ultrasonic welding.

[0006] The battery according to an aspect of the present disclosure includes 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 portion. The support layer is composed of a resin composition having electrical insulation. The first conductive layer is laminated to the support layer. The tab portion is composed of a film-shaped member. The tab portion includes a tab body portion and a first heat dissipation portion. The tab body portion is joined to the first conductive layer by ultrasonic welding. The tab body portion extends away from the first conductive layer. The first heat dissipation portion is shorter than the tab body portion in the extending direction of the tab body portion. The first heat dissipation portion is not joined to the first conductive layer by ultrasonic welding. The active material layer is laminated to the first conductive layer. The separator is laminated to the active material layer. The second electrode is laminated to the active material layer with the separator interposed therebetween. The external terminal is electrically connected to the tab body portion.

[0007] According to the above structure, it is possible to suppress the heat generation at the time of energization while suppressing an increase in manufacturing cost and an increase in weight. BRIEF DESCRIPTION OF DRAWINGS

[0008] Features, advantages, and technical and industrial significance of exemplary embodiments of the present application will be described below with reference to the accompanying drawings, wherein the same reference numerals in different drawings denote the same element, and wherein:

[0009] Figure 1 is a cross-sectional view showing a battery according to Embodiment 1.

[0010] Figure 2 is a cross-sectional view of an electrode body as viewed in the direction of arrows of line II-II. Figure 1

[0011] Figure 3 is a schematic cross-sectional view of an electrode body as viewed in the direction of arrows of line III-III. Figure 1

[0012] Figure 4 is an expanded view of the first electrode.

[0013] Figure 5A is a partial cross-sectional view of the first electrode as viewed in the direction of arrows of line VA-VA. Figure 4

[0014] Figure 5B is a partial cross-sectional view of the first electrode as viewed in the direction of arrows of line VB-VB. Figure 4

[0015] Figure 6 is a partial cross-sectional view of the first electrode according to Embodiment 2. DETAILED DESCRIPTION

[0016] Hereinafter, the current collector and the battery according to each embodiment of the present disclosure will be described with reference to the drawings. The same or equivalent portions in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[0017] (Embodiment 1)

[0018] Figure 1 is a cross-sectional view showing a battery according to Embodiment 1. Figure 1 The battery 1 shown in the drawing is a so-called rectangular battery. The battery 1 can be a secondary battery configured to be chargeable and dischargeable, such as a lithium-ion battery, a nickel-hydrogen battery, or the like. The battery 1 can be used, for example, as a unit included in a power storage module mounted to an electric vehicle.

[0019] As shown in the drawing, the battery 1 includes a battery case 2, a positive electrode 3, a negative electrode 4, a separator 5, and a positive electrode terminal 6. Figure 1 ​​​​As shown, the battery 1 according to Embodiment 1 of the present disclosure includes 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 structure other than the electrode body 10 in the battery 1 will be described.

[0020] The case 20 has conductivity. The portion having conductivity in the case 20 is composed of, for example, a metal such as aluminum. The case 20 houses the electrode body 10. The case 20 also houses an electrolyte solution, which is not shown.

[0021] The case 20 includes a case body 21 and a lid 22. The case body 21 includes a bottom wall 21a and a peripheral wall 21b that stands from the bottom wall 21a.

[0022] The lid 22 is joined to the peripheral wall 21b by welding or the like in a manner of plugging the opening of the peripheral wall 21b. The lid 22 is formed with a first connecting hole 22a and a second connecting hole 22b.

[0023] The first external terminal 30A and the second external terminal 30B are disposed in the battery 1 in a manner of being exposed to the outside. The first connecting member 40A and the second connecting member 40B have conductivity. At least a portion of the first connecting member 40A and the second connecting member 40B is disposed inside the case 20.

[0024] The first external terminal 30A or the first connecting member 40A is inserted through the first connecting hole 22a. The first external terminal 30A is electrically connected to the first connecting member 40A. Specifically, the first external terminal 30A and the first connecting member 40A are joined to each other. The first connecting member 40A is joined to the electrode body 10. Thus, the first external terminal 30A is electrically connected to the electrode body 10.

[0025] The second external terminal 30B or the second connecting member 40B is inserted through the second connecting hole 22b. The second external terminal 30B is electrically connected to the second connecting member 40B. Specifically, the second external terminal 30B and the second connecting member 40B are joined to each other. The second connecting member 40B is joined to the electrode body 10. Thus, the second external terminal 30B is electrically connected to the electrode body 10.

[0026] In addition, in the present embodiment, the first external terminal 30A is a positive electrode terminal, and the second external terminal 30B is a negative electrode terminal. The first external terminal 30A and the second external terminal 30B are arranged in a second direction D2. The second direction D2 is a direction orthogonal to the first direction D1.

[0027] Next, the electrode body 10 will be described. The battery 1 according to the present embodiment is provided with a plurality of electrode bodies 10. Typically, the battery 1 is provided with two electrode bodies 10. These electrode bodies 10 are arranged in the third direction D3. The third direction D3 is a direction orthogonal to both the first direction Dl and the second direction D2.

[0028] Hereinafter, one of the plurality of electrode bodies 10 will be described. Also, each of the plurality of electrode bodies 10 can be provided with the structure described below.

[0029] Figure 2 is a cross-sectional view of the electrode body as viewed in the arrow direction of line II-II. Figure 1 Figure 3 is a schematic cross-sectional view of the electrode body as viewed in the arrow direction of line III-III. Figure 1 Figures 1 to 3 As shown in FIG. 10, the electrode body 10 includes a first electrode 11A, a second electrode 11B, and a separator 12. The first electrode 11A, the second electrode 11B, and the separator 12 are wound in the electrode body 10 in a manner surrounding the periphery of the winding axis Z. In this way, in the present embodiment, the electrode body 10 is a so-called wound electrode body. However, the electrode body 10 can also be a laminated electrode body in which the first electrode 11A and the second electrode 11B and the separator 12 are laminated in one direction (for example, the third direction D3). Also, in FIGS. 10 and 11, the separator 12 is schematically indicated by a broken line. Figure 2 Figure 3

[0030] 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 plates in which the first electrode 11A and the second electrode 11B are wound with one or more separators 12 interposed therebetween.

[0031] 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 can be a negative electrode, and the second electrode 11B can be a positive electrode.

[0032] The separator 12 is provided between the first electrode 11A and the second electrode 11B. The separator 12 is capable of allowing 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 above-mentioned ions are, for example, lithium ions. The separator 12 has electrical insulating properties.

[0033] Figure 4 is an expanded view of the first electrode. That is, in FIG. 9, a state before the first electrode 11A is wound is shown. Figure 4 Figure 5A is a partial cross-sectional view of the first electrode as viewed in the arrow direction of line VA-VA. Figure 4 Figure 5B ​​​​​​is observed from the direction of the VB-VB arrow Figure 4 a partial cross-sectional view of the 1st electrode.

[0034] As shown in Figures 2 to 5B the 1st electrode 11A includes a 1st current collector 100A, a 1st active material layer 200A, a 1st protective portion 400, and a 2nd protective portion 500.

[0035] The 1st current collector 100A includes a support layer 110, a 1st conductive layer 120, a 2nd conductive layer 130, a plurality of tab portions 140, and a plurality of adhesive members 150.

[0036] The support layer 110 is composed of a resin composition having electrical insulating properties. Therefore, the 1st current collector 100A is a composite current collector composed of a conductive member and an electrically insulating member. Thereby, compared to a case where the 1st current collector 100A is composed of metal as a whole, the 1st current collector 100A becomes lighter, and the safety of the battery 1 as a whole becomes higher.

[0037] The support layer 110 is composed of, for example, a resin composition including a polyamide-based resin, a polyester-based resin, or a polyolefin-based resin. In order to improve rigidity, the support layer 110 is preferably composed of a resin composition including a polyester-based resin. The support layer 110 is more preferably composed substantially of a polyester-based resin. The polyester-based resin can be, for example, polyethylene terephthalate. Thereby, it is possible to improve the rigidity of the 1st current collector 100A while maintaining the electrical insulating properties of the support layer 110. Even, it is possible to form the support layer 110 relatively thinly.

[0038] An orthogonal direction DO orthogonal to the thickness direction DT of the support layer 110 is substantially parallel to the 1st direction D1. That is, the support layer 110 extends substantially in parallel to the 1st direction D1.

[0039] Regarding the thickness of the support layer 110, in order to make the overall thickness of the electrode body 10 thin, it is preferable to be, for example, 20 μm or less, more preferably 15 μm or less, and further preferably 10 μm or less. The thickness of the support layer 110 is not particularly limited as long as it has desired rigidity. The thickness of the support layer 110 can be, for example, 2 μm or more.

[0040] The 1st conductive layer 120 is laminated to the support layer 110. The 1st conductive layer 120 is provided on one face of the support layer 110. The 1st conductive layer 120 is provided on the entire of the one face.

[0041] In the present embodiment, the 1st conductive layer 120 is located on the side of the winding axis Z when viewed from the support layer 110. However, the 1st conductive layer 120 can be located on the side opposite to the side of the winding axis Z when viewed from the support layer 110.

[0042] The second conductive layer 130 is laminated to the support layer 110 on the opposite side of the first conductive layer 120. That is, the second conductive layer 130 is provided on the other face of the support layer 110. The second conductive layer 130 is provided on the entire of the other face.

[0043] 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. As for the thickness of the first conductive layer 120 and the thickness of the second conductive layer 130, in order to make the entire thickness of the electrode body 10 thin, for example, 5 μm or less, more preferably 2 μm or less, further preferably 1 μm or less. As for the thickness of the first conductive layer 120 and the thickness of the second conductive layer 130, in order to suppress the electrical resistance of the first conductive layer 120 and the second conductive layer 130 from becoming too large, for example, 0.1 μm or more is sufficient. Further, in the case where the thickness of the first conductive layer 120 and the thickness of the second conductive layer 130 are 5 μm or less, it is difficult to directly weld or directly join the first conductive layer 120 and the second conductive layer 130 to each other by ultrasonic welding.

[0044] The method of 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 can 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 can also be composed of a metal film. In this case, the first conductive layer 120 and the second conductive layer 130 can also be adhered to the support layer 110 via a resin adhesive.

[0045] In addition, typically, the first conductive layer 120 and the second conductive layer 130 are composed of a metal containing aluminum. Thereby, the first current collector 100A provided with the first conductive layer 120 and the second conductive layer 130 can be appropriately used as a positive electrode current collector. Further, the first current collector 100A can also be a negative electrode current collector, and the first conductive layer 120 and the second conductive layer 130 can also be composed of a metal containing copper.

[0046] As shown in FIG. 1, a plurality of tab portions 140 are arranged in the winding direction DR of the electrode body 10. The plurality of tab portions 140 are separated from each other. Figure 4 Further, as shown in FIG. 1, the plurality of tab portions 140 are arranged in the third direction D3. The plurality of tab portions 140 are joined to each other by ultrasonic joining or the like. Furthermore, as shown in FIG. 1, the plurality of tab portions 140 are joined to the first connecting member 40A by ultrasonic joining or the like. Thereby, the first external terminal 30A is electrically connected to the tab portions 140. Hereinafter, the structure provided for each of the plurality of tab portions 140 will be described.

[0047] Figure 2 Figure 1

[0048] ​​​The lug 140 is composed of a membrane-like component. Typically, the lug 140 is composed of a metal membrane containing aluminum or copper.

[0049] like Figure 5A As shown, the lug portion 140 includes a lug body portion 141, a first heat dissipation portion 142, a second heat dissipation portion 143, and a connecting auxiliary portion 144.

[0050] The lug body 141 is joined to the first conductive layer 120 by ultrasonic welding. The lug body 141 extends on the first conductive layer 120 along the orthogonal direction DO (first direction D1). The lug body 141 extends away from the first conductive layer 120. The extension direction DE of the lug body 141 is substantially parallel to the orthogonal direction DO (first direction D1).

[0051] like Figure 4 As shown, the first heat dissipation part 142 is connected to the lug body part 141 in the winding direction DR. The first heat dissipation part 142 is formed by a component integral with the lug body part 141. The first heat dissipation part 142 is shorter than the lug body part 141 in the extending direction DE of the lug body part 141.

[0052] like Figure 5B As shown, the first heat dissipation portion 142 is located on the side opposite to the support layer 110 when viewed from the first conductive layer 120. The first heat dissipation portion 142 is not joined to the first conductive layer 120 by ultrasonic welding. However, the first heat dissipation portion 142 is in contact with the first conductive layer 120.

[0053] The second heat dissipation portion 143, when viewed from the support layer 110, is located on the side opposite to the first conductive layer 120. More specifically, the second heat dissipation portion 143, when viewed from the second conductive layer 130, is located on the side opposite to the support layer 110. The second heat dissipation portion 143 is not joined to the second conductive layer 130 by ultrasonic welding. However, the second heat dissipation portion 143 is in contact with the second conductive layer 130. The second heat dissipation portion 143 is aligned with the first heat dissipation portion 142 in the thickness direction DT.

[0054] like Figure 5A As shown, the joining auxiliary portion 144 is joined to the second conductive layer 130 by ultrasonic welding. The joining auxiliary portion 144 extends on the second conductive layer 130 along the orthogonal direction DO (first direction D1). The joining auxiliary portion 144 extends from the second conductive layer 130 in the extension direction DE. The joining auxiliary portion 144 is also joined to the lug body portion 141 by ultrasonic welding. The joining auxiliary portion 144 is shorter than the lug body portion 141 in the extension direction DE. In addition, the joining auxiliary portion 144 is aligned with the lug body portion 141 in the thickness direction DT. Moreover, the joining auxiliary portion 144 is connected to the second heat dissipation portion 143 in the winding direction DR (see reference). Figure 4The engagement auxiliary part 144 is formed by a component integral with the second heat dissipation part 143.

[0055] The thickness of each of the lug body 141, the first heat dissipation portion 142, the second heat dissipation portion 143, and the joining auxiliary portion 144 is greater than the thickness of each of the first conductive layer 120 and the second conductive layer 130. The thickness of each of the lug body 141, the first heat dissipation portion 142, the second heat dissipation portion 143, and the joining auxiliary portion 144 is preferably 20 μm or less, more preferably 15 μm or less, and even more preferably 10 μm or less. The thickness of these components is not particularly limited as long as they possess the desired rigidity. For example, the thickness of these components can be 2 μm or more.

[0056] The adhesive member 150 joins a first end 142e, which is the end of the first heat dissipation portion 142 in the extending direction DE, and a second end 143e, which is the end of the second heat dissipation portion 143 in the extending direction DE, together. The material constituting the adhesive member 150 is not particularly limited, and for example, it may be an adhesive resin. The adhesive member 150 may also be made conductive by including a metal filler or the like in the resin. In this case, the first end 142e and the second end 143e are electrically connected.

[0057] like Figure 2 as well as Figure 3 As shown, the first active material layer 200A is stacked 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 can also be a negative electrode active material layer. The first active material layer 200A is separated from the tab 140.

[0058] Spacer 12 is stacked onto the first active material layer 200A in a radial direction centered on the winding axis Z.

[0059] The first protective section 400 is made of ceramic, which has electrical insulation properties. For example... Figure 5A As shown, the first protective portion 400 covers a portion of the first active material layer 200A, which is laminated to the first conductive layer 120, on the side extending in the DE 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 tab body portion 141. The first protective portion 400 is also partially disposed between the first conductive layer 120 and the tab body portion 141.

[0060] The second protective portion 500 is made of ceramic having electrical insulation. The second protective portion 500 covers a portion of the first active material layer 200A stacked to the second conductive layer 130 on the extension direction DE side. The second protective portion 500 covers the entire surface of the second conductive layer 130 between the first active material layer 200A and the joining auxiliary portion 144. Further, the second protective portion 500 is also partially disposed between the second conductive layer 130 and the joining auxiliary portion 144.

[0061] As shown in FIG. 1, the second electrode 11B is stacked to the first active material layer 200A through the spacer 12 in the above-mentioned radial direction. In the present embodiment, the electrode body 10 includes a plurality of spacers 12, but can include one spacer 12. Figure 2 Figure 3 As shown in FIG. 1, the second electrode 11B is stacked to the first active material layer 200A through the spacer 12 in the above-mentioned radial direction. In the present embodiment, the electrode body 10 includes a plurality of spacers 12, but can include one spacer 12.

[0062] The second electrode 11B includes the second current collector 100B and the second active material layer 200B. The second current collector 100B includes the conductive support portion 170 and a plurality of second tab portions 180 (refer to FIG. 2). Figure 3 ) The conductive support portion 170 extends along the orthogonal direction DO (the first direction Dl). 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 joined to the second link member 40B (refer to FIG. 2). Figure 1

[0063] The plurality of second tab portions 180 and the conductive support portion 170 are made of an integral member, for example, a metal film. In the present embodiment, the plurality of second tab portions 180 and the conductive support portion 170 are made of, for example, a metal containing copper. Thereby, the second current collector 100B can be appropriately used as a negative electrode current collector. Further, in the case where the first current collector 100A is a negative electrode current collector and the second current collector 100B is a positive electrode current collector, the plurality of second tab portions 180 and the conductive support portion 170 can also be made of a metal containing aluminum.

[0064] The second active material layer 200B is stacked to both surfaces of the conductive support portion 170 of the second current collector 100B. Further, in the present embodiment, the second electrode 11B is a negative electrode. Therefore, the second active material layer 200B is a negative electrode active material layer. Further, the second active material layer 200B can also be a positive electrode active material layer.

[0065] ​​As described above, the first current collector 100A according to Embodiment 1 of the present disclosure includes the support layer 110, the first conductive layer 120, and the tab portion 140. The support layer 110 is composed of a resin composition having electrical insulation. The first conductive layer 120 is laminated to the support layer 110. The tab portion 140 is composed of a film-like member. The tab portion 140 includes the tab body portion 141 and the first heat dissipation portion 142. The tab body portion 141 is joined to the first conductive layer 120 by ultrasonic welding. The tab body portion 141 extends away from the first conductive layer 120. The first heat dissipation portion 142 is shorter than the tab body portion 141 in the extension direction DE of the tab body portion 141. The first heat dissipation portion 142 is not joined to the first conductive layer 120 by ultrasonic welding.

[0066] By ultrasonic welding, the energy used in the connection of the first conductive layer 120 and the tab portion 140 can be reduced. Also, by the tab portion 140 including the first heat dissipation portion 142, the heat generated from the tab body portion 141 at the time of energization can be easily released. In addition, by making the first heat dissipation portion 142 shorter than the tab body portion 141 in the extension direction DE, the increase in the weight of the first current collector 100A can be suppressed. Furthermore, the first heat dissipation portion 142 is not joined to the first conductive layer 120 by ultrasonic welding. Thus, regardless of the shape of the first heat dissipation portion 142, which is relatively short in the extension direction DE, the tab portion 140 can be easily connected to the first conductive layer 120 by a simple process.

[0067] Therefore, according to the above structure, the first current collector 100A, in which the heat at the time of energization is suppressed while the increase in manufacturing cost and the weight is suppressed, and the battery 1 including the same can be provided.

[0068] In addition, the above structure can also have the following effects. The first heat dissipation portion 142 has the above shape, so in the case where the first heat dissipation portion 142 is also joined to the first conductive layer 120 by ultrasonic welding, it is also considered necessary to ultrasonic weld an original fabric film to the first conductive layer 120 and then cut the tab portion 140 including the first heat dissipation portion 142 from the original fabric film. Therefore, the loss of the original fabric film due to disposal can be large. That is, according to the above structure, the tab portion 140 can be easily joined to the first conductive layer 120 after the tab portion 140 is cut from the original fabric film. Thus, the degree of freedom in cutting the tab portion 140 from the original fabric film is increased, and the loss of the original fabric film, which is a raw material of the tab portion 140, due to disposal is expected to be reduced.

[0069] In addition, in the present embodiment, the first current collector 100A further includes an adhesive member 150. The tab portion 140 further includes a second heat dissipation portion 143. The first heat dissipation portion 142 is located on the side opposite to the support layer 110 when viewed from the first conductive layer 120. The second heat dissipation portion 143 is located on the side opposite to the first conductive layer 120 when viewed from the support layer 110. The adhesive member 150 joins the first end portion 142e, which is an end portion of the first heat dissipation portion 142 in the extension direction DE, and the second end portion 143e, which is an end portion of the second heat dissipation portion 143 in the extension direction DE, to each other.

[0070] According to the above structure, the heat of the tab portion 140 at the time of energization can be more effectively dissipated using the first heat dissipation portion 142 and the second heat dissipation portion 143.

[0071] In addition, in the present embodiment, the first heat dissipation portion 142 is in contact with the first conductive layer 120.

[0072] According to the above structure, at the time of energization of the first conductive layer 120 and the tab portion 140, a current also flows in the first heat dissipation portion 142, so it is possible to suppress the heat generation in the connecting portion of the tab body portion 141 and the first conductive layer 120.

[0073] In addition, in the present embodiment, the second heat dissipation portion 143 is in contact with the second conductive layer 130. The first end portion 142e and the second end portion 143e are electrically connected.

[0074] According to the above structure, it is possible to secure the conductive path from the second conductive layer 130 to the tab portion 140 using the second heat dissipation portion 143.

[0075] (Embodiment 2)

[0076] Next, the first current collector and the battery according to Embodiment 2 of the present disclosure will be described. Furthermore, regarding the same structure and effects as Embodiment 1, sometimes the description will not be repeated.

[0077] Figure 6 is a partial cross-sectional view of the first electrode of Embodiment 2. In Figure 6 , a cross section from a direction corresponding to the cross-sectional view of Figure 5B of Embodiment 1 is shown. As shown in Figure 6 , in Embodiment 2 of the present disclosure, the second end portion 143ea is directly connected to the first end portion 142e. According to this structure, by causing one flat film constituting the tab portion 140 to be folded back at a portion corresponding to the connecting portion of the first end portion 142e and the second end portion 143ea, the second heat dissipation portion 143a can be formed relatively easily. Furthermore, even in the present embodiment, the first end portion 142e is electrically connected to the second end portion 143ea.

[0078] In the description of the above embodiments, the structures that can be combined can also be combined with each other.

[0079] It should be considered that the embodiments disclosed herein are merely illustrative and not restrictive in all points. The scope of the present disclosure is not the above description but is shown by the claims, and it is intended to include all modifications within the meaning and scope of the claims.

Claims

1. A current collector, comprising: support layer The first conductive layer, and lugs, The support layer is composed of a resin composition that has electrical insulation properties. The first conductive layer is stacked onto the support layer. The auricle is composed of a membranous component. The protruding part includes a protruding body part and a first heat dissipation part. The lug body is bonded to the first conductive layer by ultrasonic welding. The lug body extends away from the first conductive layer. The first heat dissipation part is shorter than the ear body part in the extending direction of the ear body part. The first heat dissipation part is not bonded to the first conductive layer by ultrasonic welding.

2. The current collector according to claim 1, wherein, It also has adhesive components. The protruding part also includes a second heat dissipation part. The first heat dissipation portion is located on the side opposite to the support layer when viewed from the first conductive layer. The second heat dissipation section is located on the opposite side of the first conductive layer when viewed from the support layer. The adhesive component joins the first end, which is the end of the first heat dissipation part in the extension direction, and the second end, which is the end of the second heat dissipation part in the extension direction, together.

3. The current collector according to claim 1, wherein, The protruding part also includes a second heat dissipation part. The first heat dissipation portion is located on the side opposite to the support layer when viewed from the first conductive layer. The second heat dissipation section is located on the opposite side of the first conductive layer when viewed from the support layer. The second end, which is the end of the second heat dissipation part in the extending direction, is directly connected to the first end, which is the end of the first heat dissipation part in the extending direction.

4. The current collector according to claim 2 or 3, wherein, It also has a second conductive layer. The second conductive layer is stacked onto the support layer on the opposite side of the first conductive layer. The first heat dissipation part is in contact with the first conductive layer. The second heat dissipation part is in contact with the second conductive layer. The first end is electrically connected to the second end.

5. A battery comprising: Electrode body, and external terminals, The electrode body includes a first electrode, a second electrode, and a spacer. 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 lug. The support layer is composed of a resin composition that has electrical insulation properties. The first conductive layer is stacked onto the support layer. The auricle is composed of a membranous component. The protruding part includes a protruding body part and a first heat dissipation part. The lug body is bonded to the first conductive layer by ultrasonic welding. The lug body extends away from the first conductive layer. The first heat dissipation part is shorter than the ear body part in the extending direction of the ear body part. The first heat dissipation part is not bonded to the first conductive layer by ultrasonic welding. The active material layer is stacked onto the first conductive layer. The spacer is stacked onto the active material layer. The second electrode is stacked onto the active material layer through the spacer. The external terminal is electrically connected to the lug body.

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