Electrode component with current collection tab

Abstract

The present invention provides an electrode member with current-collecting tabs that can reduce the number of current-collecting tabs while ensuring sufficient conductivity between the current-collecting tabs and the first and second conductive layers formed on the main body side of the resin substrate. [Solution] The electrode member with a current-collecting tab comprises a resin substrate 110 having a first main surface 110a, a second main surface 110b, and a first end surface 110c, a current-collecting tab joined to the resin substrate 110, a first conductive layer 120, and a second conductive layer 130. The resin substrate 110 includes a main body portion 111 and a protruding piece portion 112. The current-collecting tab has a first surface 160a including a joining portion 160j, a second surface 160b, and a tab end surface 160c. The first conductive layer 120 extends from the main body portion 111 side toward the first end surface 160c and covers a portion of the first surface 160a located on one side of the joining portion 160j in the first direction. The second conductive layer 130 extends from the main body portion 111 side toward the tab end surface 160c and covers a portion of the second surface 160b.

Description

【Technical Field】 , , , 【0004】 , , 【0006】 , , , , 【0005】 , , , , 【0001】 The present disclosure relates to an electrode member with a current collecting tab. 【Background Art】 【0002】 As a conventional wound electrode body, in Japanese Patent Application Laid-Open No. 2019-096592 (Patent Document 1), an electrode in which a conductive layer and an active material layer are laminated in this order on the surface of an insulating substrate (resin substrate) is used for at least one of a sheet-like positive electrode and a negative electrode. A structure in which a separator is disposed between the positive electrode and the negative electrode and these are wound is disclosed. The conductive layer includes a first portion on which the active material layer is coated and a second portion protruding from the first portion. Through holes penetrating in the thickness direction are provided in the second portion and the portion of the insulating substrate corresponding to the second portion. 【Prior Art Documents】 【Patent Documents】 【0003】 【Patent Document 1】 [[ID=​​​​​​​​​​​​​​​​ However, since the current collector tabs are joined at a composite joint where the resin substrate and the conductive layer are mixed by ultrasound, an insulating layer is present at the joint, reducing the conductivity from the current collector tabs. In addition, the number of parts increases because the resin substrate is used to sandwich the current collector tabs. 【0007】 This disclosure has been made in view of the above-mentioned problems, and the purpose of this disclosure is to provide an electrode member with current-collecting tabs that can reduce the number of current-collecting tabs while ensuring sufficient conductivity between the current-collecting tabs and the first conductive layer and the second conductive layer formed on the main body side of the resin substrate. [Means for solving the problem] 【0008】 The electrode member with a current-collecting tab according to this disclosure comprises a resin substrate having a first main surface and a second main surface aligned in the thickness direction, and a first end surface located at one end in a first direction perpendicular to the thickness direction; a current-collecting tab joined to the resin substrate; a first conductive layer including a portion provided on the first main surface and connected to the current-collecting tab; and a second conductive layer including a portion provided on the second main surface and connected to the current-collecting tab. The resin substrate includes a main body portion located on the other side of the first direction and a protruding piece portion projecting from the main body portion to the one side of the first direction. The current-collecting tab has a first surface including a joint portion joined to the second main surface located on the protruding piece portion, a second surface located on the opposite side of the first surface, and a tab end surface located at one end on the other side of the first direction. The first conductive layer extends on the first main surface from the main body side toward the first end face and covers the first end face and a portion of the first surface located on one side of the joint in the first direction. The second conductive layer extends on the second main surface from the main body side toward the tab end face and covers the tab end face and a portion of the second surface. 【0009】 According to the above configuration, the current-collecting tabs are directly bonded to the resin substrate, and conductive layers extend from both sides of the resin substrate to both sides of the current-collecting tabs. Furthermore, conductive layers are directly bonded to both sides of the current-collecting tabs. Therefore, it is possible to reduce the number of current-collecting tabs while ensuring sufficient conductivity between the first and second conductive layers formed on the main body and the current-collecting tabs. 【0010】 In the electrode member with a current-collecting tab according to the above disclosure, the first conductive layer may have a tip-side portion that covers a part of the first surface located on one side of the joint in the first direction. In this case, the thickness of the tip-side portion may be thicker than the portion of the first conductive layer located on the first main surface. 【0011】 According to the above configuration, by making the thickness of the tip portion formed on the current collector tab of the first conductive layer greater than the thickness of the first conductive layer formed on the first main surface of the resin substrate, the conductivity between the current collector tab and the first conductive layer can be improved. 【0012】 The electrode member with a current-collecting tab according to the above disclosure may further comprise an active material layer including a first portion located on the first main surface side and a second portion located on the second main surface side. The first portion may be provided on the portion of the first conductive layer formed on the first main surface of the main body. The second portion may be provided on the portion of the second conductive layer formed on the second main surface of the main body. The first portion may have a first corner on one side in the first direction. The second portion may have a second corner on one side in the first direction. The electrode member with a current-collecting tab may further comprise a first protective layer covering at least the first corner of the first portion and a second protective layer covering at least the second corner of the second portion. 【0013】 According to the above configuration, the first protective layer is placed at the first corner of the first portion of the active material layer, and the second protective layer is placed at the second corner of the second portion of the active material layer, thereby protecting the first and second corners. More specifically, when an electrode body is formed using the electrode material with current-collecting tabs and a separator, it is possible to prevent the separator from being torn by the first and second corners. [Effects of the Invention] 【0014】 According to this disclosure, it is possible to provide an electrode member with current-collecting tabs that can reduce the number of current-collecting tabs while ensuring sufficient conductivity between the current-collecting tabs and the first conductive layer and the second conductive layer formed on the main body side of the resin substrate. [Brief explanation of the drawing] 【0015】 [Figure 1] This is a cross-sectional view showing a battery according to an 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 an exploded view of the first electrode member according to the embodiment. [Figure 4] This is a partial cross-sectional view of the first electrode member shown in Figure 3, viewed in the direction of the arrow between lines IV and IV. [Modes for carrying out the invention] 【0016】 The embodiments of this disclosure will be described in detail below with reference to the drawings. In the embodiments described below, the same or common parts are denoted by the same reference numerals in the drawings, and their descriptions will not be repeated. 【0017】 Figure 1 is a cross-sectional view showing a battery according to an 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. 【0018】 As shown in FIG. 1, a battery 1 according to an embodiment 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 components of the battery 1 other than the electrode body 10 will be described. 【0019】 The case 20 has conductivity. The conductive portion of the case 20 is made of a metal such as aluminum. The case 20 houses the electrode body 10. The case 20 also houses an electrolytic solution (not shown). 【0020】 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 rising from the bottom wall 21a. 【0021】 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. 【0022】 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 have conductivity. At least a part of the first connecting member 40A and the second connecting member 40B is disposed inside the case 20. 【0023】 The first external terminal 30A or the first connecting member 40A is inserted into the first connection 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. Thereby, the first external terminal 30A is electrically connected to the electrode body 10. 【0024】 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. As a result, the second external terminal 30B is electrically connected to the electrode body 10. 【0025】 In this embodiment, the first external terminal 30A is the positive terminal and the second external terminal 30B is the negative terminal, but the embodiment is not limited to this, and the first external terminal 30A may be the negative terminal and the second external terminal 30B may be the positive 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. The first direction D1 is parallel to the height direction of the battery 1 and is parallel to the vertical direction. 【0026】 Next, the electrode bodies 10 will be described. The battery 1 according to this embodiment comprises a plurality of electrode bodies 10. Typically, the battery 1 comprises two electrode bodies 10. These electrode bodies 10 are aligned in a third direction D3. The third direction D3 is a direction perpendicular to both the first direction D1 and the second direction D2. 【0027】 In the following description, one of the multiple electrode bodies 10 will be explained. Note that each of the multiple electrode bodies 10 may have the configuration shown below. 【0028】 Figure 2 is a cross-sectional view of the electrode body of Figure 1, viewed in the direction of the arrow line II-II. As shown in Figures 1 and 2, 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 a winding axis Z. Thus, in this embodiment, the electrode body 10 is a so-called wound electrode body. However, the electrode body 10 may also be a laminated electrode body in which the first electrode 11A, the second electrode 11B, and the separator 12 are stacked in one direction (for example, a third direction D3). In Figure 2, the separator 12 is schematically shown by a dashed line. 【0029】 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 around one or more separators 12. In this embodiment, the first electrode 11A is the positive electrode and the second electrode 11B is the negative electrode. However, the first electrode 11A may be the negative electrode and the second electrode 11B may be the positive electrode. 【0030】 The separator 12 is provided between the first electrode 11A and the second electrode 11B. The separator 12 separates the first electrode 11A and the second electrode 11B while allowing ions to move between them. The ions are, for example, lithium ions. The separator 12 has electrical insulating properties. 【0031】 Figure 3 is an unfolded view of the first electrode member according to the embodiment. That is, Figure 3 shows the state before the first electrode 11A is wound. Figure 4 is a partial cross-sectional view of the first electrode in Figure 3, viewed in the direction of the arrow IV-IV. 【0032】 As shown in Figures 2 to 4, the first electrode 11A comprises a resin substrate 110, a first conductive layer 120, a second conductive layer 130, a plurality of current-collecting tabs 160, a first active material layer 200A, a first protective part 400, and a second protective part 500. The first electrode 11A corresponds to an electrode member with current-collecting tabs. 【0033】 The resin substrate 110 is made of a resin composition having electrical insulating properties. The resin substrate 110 is made of a resin composition that includes, for example, a polyamide resin, a polyester resin, or a polyolefin resin. 【0034】 The resin substrate 110 has a first main surface 110a and a second main surface 110b aligned in the thickness direction DT. The thickness direction DT is perpendicular to the first direction D1. The resin substrate 110 has a first end surface 110c located at one end (one side end) of the first direction D1. 【0035】 The thickness of the resin substrate 110 in the thickness direction DT 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 overall thickness of the resin substrate 110 is not particularly limited as long as it has the desired rigidity. The thickness of the resin substrate 110 may be, for example, 2 μm or more. 【0036】 The resin substrate 110 includes a main body portion 111 and a plurality of protruding pieces 112. The main body portion 111 occupies most of the resin substrate 110. The main body portion 111 is the portion wound around the winding axis Z. The first active material layer 200A described above is provided in the region overlapping the main body portion 111. 【0037】 Each of the multiple protruding pieces 112 protrudes from the main body 111 to one side in a first direction. The multiple protruding pieces 112 are spaced apart from each other in the winding direction DR. Each of the multiple protruding pieces 112 is provided with a current collecting tab 160. 【0038】 Each current-collecting tab 160 is joined to the corresponding protruding piece 112. One current-collecting tab 160 is joined to each protruding piece 112. The current-collecting tab 160 is joined to the second main surface 110b located on the protruding piece 112. The current-collecting tab 160 is directly joined to the second main surface 110b by ultrasonic welding or the like. 【0039】 The current collector tab 160 has a first surface 160a, a second surface 160b, and a tab end surface 160c. The first surface 160a and the second surface 160b are aligned in the thickness direction DT described above in the portion that extends parallel to the resin substrate 110. 【0040】 The first surface 160a includes a joint 160j joined to the second main surface 110b located on the protruding piece 112. The second surface 160b is located on the opposite side in the thickness direction from the side where the first surface 160a is located. The tab end surface 160c is located at one end on the other side in the first direction D1. 【0041】 The first conductive layer 120 includes a portion provided on the first main surface 110a. The first conductive layer 120 includes a portion provided on the first main surface 110a of the main body portion 111 and a portion provided on the first main surface 110a of the protruding piece portion 112. The first conductive layer 120 is provided over substantially the entire surface of the first main surface 110a. 【0042】 The first conductive layer 120 extends on the first main surface 110a from the main body portion 111 side toward the first end surface 110c, and covers the first end surface 110c and a portion of the first surface 160a located on one side in the first direction D1 from the joint portion 160j. 【0043】 The first conductive layer 120 has a tip portion 120t on one side in the first direction D1. The tip portion 120t covers a part of the first surface 160a that is located on one side in the first direction D1 than the joint portion 160j. 【0044】 The thickness of the tip portion 120t is greater than the portion of the first conductive layer 120 located on the first main surface 110a. This improves the conductivity between the current collector tab 160 and the first conductive layer 120. 【0045】 The second conductive layer 130 includes a portion provided on the second main surface 110b. The second conductive layer 130 includes a portion provided on the second main surface 110b of the main body portion 111 and a portion provided on the second main surface 110b of the protruding piece portion 112. The second conductive layer 130 is provided over substantially the entire surface of the second main surface 110b. 【0046】 The second conductive layer 130 extends from the main body portion 111 side toward the tab end face 160c on the second main surface 110b, and covers the tab end face 160c and a portion of the second surface 160b. 【0047】 The first conductive layer 120 and the second conductive layer 130 are made of a metallic material containing aluminum. When the first electrode 11A is the negative electrode, it is preferable that the first conductive layer 120 and the second conductive layer 130 are made of a metallic material containing copper. The first conductive layer 120 and the second conductive layer 130 can be formed, for example, by vapor deposition. 【0048】 The first active material layer 200A is, for example, a positive electrode active material layer. A known positive electrode active material layer can be used. 【0049】 The first active material layer 200A has a first portion 201 and a second portion 202. The first portion 201 is located on the first main surface 110a side. The second portion 202 is located on the second main surface 110b side. 【0050】 The first portion 201 is provided on the portion of the first conductive layer 120 that is formed on the first main surface 110a of the main body portion 111. The first portion 201 is formed in a substantially rectangular shape when viewed from the thickness direction DT. 【0051】 The first part 201 includes an outer surface 201a, an end face 201c, and a corner 201d (first corner). The outer surface 201a is located on one side in the thickness direction DT. The outer surface 201a is located on the opposite side in the thickness direction DT from the side where the resin substrate 110 is located. The end face 201c is located at one end in the first direction. The corner 201d is the portion where the outer surface 201a and the end face 201c intersect. The corner 201d is located away from the first main surface 110a on one side in the thickness direction DT. 【0052】 The second portion 202 is provided on the portion of the second conductive layer 130 that is formed on the second main surface 110b of the main body portion 111. The second portion 202 is formed in a substantially rectangular shape when viewed from the thickness direction DT. 【0053】 The second portion 202 includes an outer surface 202a, an end face 202c, and a corner 202d (second corner). The outer surface 202a is located on the other side in the thickness direction DT. The outer surface 202a is located on the opposite side in the thickness direction DT from the side where the resin substrate 110 is located. The end face 202c is located at one end in the first direction. The corner 202d is the portion where the outer surface 202a and the end face 202c intersect. The corner 202d is located away from the second main surface 110b on the other side in the thickness direction DT. 【0054】 The first protective portion 400 covers at least the corner portion 201d. The first protective portion 400 covers at least the portion of the first part 201 located on one side in the first direction. The first protective portion 400 has a first covering portion 401, a second covering portion 402, and a third covering portion 403. 【0055】 The first covering portion 401 covers the portion of the outer surface 201a located on one side in the first direction. The second covering portion 402 covers the end face 201c. The third covering portion 403 extends from the second covering portion 402 along the first direction and covers the first conductive layer 120 provided on the protruding piece 112. 【0056】 In this embodiment, the third covering portion 403 does not cover the tip portion 120t, and the case where the tip portion 120t is exposed from the third covering portion 403 is illustrated, but the embodiment is not limited to this. The third covering portion 403 may cover the tip portion 120t. When the third covering portion 403 covers the tip portion 120t, the portion of the first conductive layer 120 that contacts the current collector tab 160 can also be protected. 【0057】 The second protective portion 500 covers at least the corner portion 202d. The second protective portion 500 covers at least the portion of the second portion 202 located on one side in the first direction. The second protective portion 500 has a first covering portion 501, a second covering portion 502, a third covering portion 503, a fourth covering portion 504, and a fifth covering portion 505. 【0058】 The first covering portion 501 covers the portion of the outer surface 202a located on one side in the first direction. The second covering portion 502 covers the end face 202c. The third covering portion 503 extends from the second covering portion 502 along the first direction and covers the portion of the second conductive layer 130 from the second portion 202 to the tab end face 160c. The fourth covering portion 504 covers the portion of the second conductive layer 130 formed on the tab end face 160c. The fifth covering portion 505 covers the portion of the second conductive layer 130 formed on a part of the second surface 160b. 【0059】 The first protective section 400 and the second protective section 500 are made of an insulating ceramic material. 【0060】 In this way, the first protective part 400 covers at least the corner 201d and the second protective part 500 covers at least the corner 202d, thereby protecting the corners 201d and 202d. This prevents the separator 12 from being torn by the corners 201d and 202d in the electrode body 10. 【0061】 As shown again in Figure 2, the second electrode 11B is stacked on the first active material layer 200A via a separator 12 in the radial direction of the electrode body 10. 【0062】 The second electrode 11B includes a current collector 100B and a second active material layer 200B. The current collector 100B is drawn out from between the second active material layers 200B to one side in the first direction D1. The current collector 100B is joined to the second connecting member 40B by ultrasonic welding (see Figure 1). 【0063】 The current collector 100B is made of, for example, a metal film. The current collector 100B is made of, for example, a metal containing copper. This makes the current collector 100B suitable for use as a negative electrode current collector. When the first electrode 11A is the negative electrode and the second electrode 11B is the positive electrode, the current collector 100B may be made of a metal containing aluminum. The second electrode 11B may also have the same configuration as the first electrode 11A. 【0064】 The second active material layer 200B is laminated on both sides of the current collector 100B. The second active material layer 200B is the negative electrode active material layer. Known materials can be used as the negative electrode active material layer. If the second electrode 11B is the positive electrode, the second active material layer 200B may be the positive electrode active material layer. 【0065】 As described above, in the first electrode 11A according to this embodiment, the first conductive layer 120 extends on the first main surface 110a from the main body portion 111 side toward the first end surface 110c, and covers the first end surface 110c and a part of the first surface 160a located on one side in the first direction from the joint portion 160j. The second conductive layer 130 extends on the second main surface 110b from the main body portion 111 side toward the tab end surface 160c, and covers the tab end surface 160c and a part of the second surface 160b. 【0066】 In this manner, the current-collecting tab 160 is directly bonded to the resin substrate 110, and conductive layers (first conductive layer 120 and second conductive layer 130) extend from both sides of the resin substrate 110 toward both sides of the current-collecting tab 160. Furthermore, conductive layers are directly bonded to both sides of the current-collecting tab 160. This makes it possible to reduce the number of current-collecting tabs 160 while ensuring sufficient conductivity between the first conductive layer 120 and the second conductive layer 130 formed on the main body 111 side and the current-collecting tab 160. 【0067】 Furthermore, as will be described later, since the second surface 160b of the portion located on the back side of the joint 160j is covered by the second protective part 500, burrs formed when joining the resin substrate 110 and the current collector tab 160 can be covered by the second protective part 500. This makes it possible to suppress short circuits of the battery 1 caused by burrs during joining. 【0068】 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] 【0069】 1 Battery, 10 Electrode body, 11A First electrode, 11B Second electrode, 12 Separator, 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, 100B Current collector, 110 Resin substrate, 110a First main surface, 110b Second main surface, 110c First end surface, 111 Main body part, 112 Protruding piece part, 120 First conductive layer, 120t Tip side part, 130 Second conductive layer, 160 Current collector tab, 160a First surface, 160b Second surface, 160c Tab end surface, 160j Joint part, 200A First active material layer, 200B Second active material layer, 201 First part, 201a Outer surface, 201c End face, 201d Corner, 202 Second part, 202a Outer surface, 202c End face, 202d Corner, 400 First protective part, 401 First covering part, 402 Second covering part, 403 Third covering part, 500 Second protective part, 501 First covering part, 502 Second covering part, 503 Third covering part, 504 Fourth covering part, 505 Fifth covering part, D1 First direction, D2 Second direction, D3 Third direction, DR Winding direction, DT Thickness direction, Z Winding axis.

Claims

[Claim 1] A resin substrate having a first main surface and a second main surface aligned in the thickness direction, and a first end surface located at one end in a first direction perpendicular to the thickness direction, A current collector tab bonded to the aforementioned resin substrate, A first conductive layer, including a portion provided on the first main surface and connected to the current collector tab, A second conductive layer, including a portion provided on the second main surface and connected to the current collector tab, The resin substrate includes a main body and a protruding piece that protrudes from the main body to one side in the first direction, The current collector tab has a first surface including a joint that is joined to the second main surface located on the protruding piece, a second surface located on the opposite side of the first surface, and a tab end surface located at one end on the other side in the first direction. The first conductive layer extends on the first main surface from the main body side toward the first end surface, and covers the first end surface and a portion of the first surface located on one side in the first direction relative to the joint. The electrode member with a current-collecting tab has a second conductive layer that extends on the second main surface from the main body side toward the tab end face and covers the tab end face and a part of the second surface. [Claim 2] The first conductive layer has a tip-side portion that covers a part of the first surface located on one side of the joint in the first direction, The electrode member with a current-collecting tab according to claim 1, wherein the thickness of the tip portion is greater than the portion of the first conductive layer located on the first main surface. [Claim 3] The active material layer further comprises a first portion located on the first main surface side and a second portion located on the second main surface side, The first portion is provided on the portion of the first conductive layer that is formed on the first main surface of the main body, The second portion is provided on the portion of the second conductive layer that is formed on the second main surface of the main body, The first portion has a first corner on one side in the first direction, The second portion has a second corner on one side in the first direction, The electrode member with a current-collecting tab according to claim 1 or 2, further comprising a first protective layer covering at least the first corner of the first portion, and a second protective layer covering at least the second corner of the second portion.

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