Electrode and battery

Abstract

This utility model discloses an electrode sheet and a battery. The electrode sheet includes a composite current collector, an active material layer, and a tab assembly. Along the width direction of the composite current collector, the composite current collector includes an adjacent first region and a second region. The active material layer is located on opposite sides of the composite current collector and coated on the first region. The tab assembly includes a first tab and a second tab, which are respectively connected to the second region and located on opposite sides of the composite current collector. The ends of the first and second tabs away from the first region extend beyond the edge contour of the composite current collector. The first and second tabs have a width along the length direction of the composite current collector, and along the width direction of the composite current collector, the width of at least one of the first and second tabs on the side away from the second region is smaller than the width on the side closer to the second region. This utility model solves the problem that the tabs on the composite current collector increase the overall weight of the battery cell.

Description

Technical Field

[0001] This application relates to the field of energy storage device technology, and more specifically, to an electrode and a battery. Background Technology

[0002] Tab welding refers to connecting a conductive material to a current collector, allowing the conductive material to output the current collected by the current collector. Typically, before attaching tabs to the electrodes of a composite current collector, a connecting piece needs to be placed on the composite current collector, and then the connecting piece is cut into a rectangular tab. A composite current collector is a type of current collector with current-collecting layers formed on opposite surfaces of a polymer substrate layer.

[0003] However, because composite current collectors have a polymer substrate layer, their temperature is higher than that of traditional metal current collectors (i.e., metal foils without a polymer substrate layer, such as copper foil and aluminum foil) at the same rate. This requires increasing the width of the tabs in the design, which will increase the overall weight of the cell. Utility Model Content

[0004] The main objective of this application is to provide an electrode and a battery to solve the problem that the tabs on the composite current collector in the prior art cause an increase in the overall weight of the battery cell.

[0005] According to one aspect of this application, an electrode is provided, comprising:

[0006] A composite current collector, along the width direction of the composite current collector, includes an adjacent first region and a second region;

[0007] An active material layer is formed along the thickness direction of the composite current collector, located on opposite sides of the composite current collector and coated in the first region.

[0008] The electrode assembly includes a first electrode and a second electrode. Along the thickness direction of the composite current collector, the first electrode and the second electrode are respectively connected to the second region and located on opposite sides of the composite current collector. Along the width direction of the composite current collector, the ends of the first electrode and the second electrode away from the first region extend beyond the edge contour of the composite current collector.

[0009] The first electrode and the second electrode have widths along the length direction of the composite current collector, and along the width direction of the composite current collector, the width of at least one of the first electrode and the second electrode on the side away from the second region is smaller than the width on the side closer to the second region.

[0010] Furthermore, at least one of the first electrode tab and the second electrode tab includes:

[0011] The first segment covers and connects to the second region;

[0012] The second segment, along the width direction of the composite current collector, is located at the end of the first segment away from the first region and outside the edge contour of the composite current collector. Along the length direction of the composite current collector, the width of the second segment is smaller than the width of the first segment.

[0013] Furthermore, the first segment includes a third region and a fourth region. Along the width direction of the composite current collector, the third region is located between the second segment and the fourth region. Along the length direction of the composite current collector, the width of the third region is not less than the width of the second segment and is less than the width of the fourth region.

[0014] Furthermore, the width of the third region gradually increases towards the fourth region; and / or,

[0015] Along the length of the composite current collector, the edge contours of the third region on both sides are arc-shaped.

[0016] Furthermore, along the width direction of the composite current collector, the length of the first segment is not less than 0.5 mm and not more than 5 mm; and / or,

[0017] Along the length of the composite current collector, the width of the first segment is not less than 10 mm and not more than 200 mm; and / or,

[0018] Along the width direction of the composite current collector, the length of the second segment is not less than 10 mm and not more than 100 mm; and / or,

[0019] Along the length of the composite current collector, the width of the second segment is not less than 5 mm and not more than 95 mm; and / or,

[0020] The thickness of the composite current collector is not less than 2 μm and not more than 20 μm.

[0021] Furthermore, along the thickness direction of the composite current collector, the first tab has a first thickness, and the second tab has a second thickness, wherein at least one of the first thickness and the second thickness is not less than 2 μm and not greater than 20 μm; and / or,

[0022] Both the first electrode and the second electrode include one of copper electrode, aluminum electrode, titanium electrode, and nickel electrode.

[0023] Furthermore, along the width direction of the composite current collector, both the first electrode tab and the second electrode tab have a first distance from the first region, the first distance being not less than 0.1 mm and not greater than 2 mm.

[0024] Furthermore, along the thickness direction of the composite current collector, the projected outer contour of the first electrode coincides with the projected outer contour of the second electrode; and / or,

[0025] Along the thickness direction of the composite current collector, there is a second spacing between the second segment of the first electrode tab and the second segment of the second electrode tab; or,

[0026] Along the width direction of the composite current collector, the second segments of both the first and second electrodes, at the ends furthest from the first segment, are connected to each other; or,

[0027] Along the width direction of the composite current collector, the first electrode tab includes a first end remote from the first region, and the second electrode tab includes a second end remote from the first region; wherein:

[0028] The first end is connected to the second electrode tab, and along the width direction of the composite current collector, the first end is located between the edge contour of the second region and the second end, or...

[0029] The second end is connected to the first tab, and along the width direction of the composite current collector, the second end is located between the edge contour of the second region and the first end.

[0030] Furthermore, the composite current collector includes:

[0031] A substrate layer, wherein the thickness of the substrate layer along its own thickness direction is not less than 3 μm and not more than 8 μm;

[0032] A conductive layer is provided on both opposite sides of the substrate layer along the thickness direction of the substrate layer. The active material layer is located on the surface of the conductive layer away from the substrate layer. The first tab and the second tab are respectively connected to the portion of the conductive layer located in the second region.

[0033] On the other hand, this application also provides a battery comprising the aforementioned electrode.

[0034] In this application, the composite current collector of the electrode sheet has a first tab and a second tab respectively disposed on opposite sides, and the first tab and the second tab are respectively connected to a second region of the composite current collector. Since the width of at least one of the first tab and the second tab away from the second region is smaller than the width of the side closer to the second region, at least one of the first tab and the second tab has a larger width in the second region where the electrode sheet generates the most heat, allowing for higher current flow (battery rate). Conversely, the width of the portion of the first tab and the second tab away from the second region is smaller. Because the current-carrying performance of the first tab and the second tab is superior to that of the composite current collector, the smaller width portion of at least one of the first tab and the second tab does not significantly increase the electrode sheet temperature, but can significantly reduce the weight of the electrode sheet, thereby effectively reducing the overall weight of the battery cell and increasing the energy density of the cell. Attached Figure Description

[0035] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0036] Figure 1 This is a top view of an electrode sheet provided in an embodiment of this application;

[0037] Figure 2 This is a schematic diagram of the structure of the first and second electrodes in the electrode assembly;

[0038] Figure 3 This is a diagram illustrating the arrangement of the first and second electrodes in one embodiment;

[0039] Figure 4 This is a schematic diagram showing the connection between the first electrode and the second electrode in one embodiment;

[0040] Figure 5 This is a schematic diagram showing the connection between the first electrode and the second electrode in one embodiment;

[0041] Figure 6 This is a schematic diagram showing the connection between the second electrode tab and the first electrode tab in one embodiment;

[0042] Figure 7 A schematic diagram showing the connection between the adapter plate and the composite current collector before the adapter plate is processed into the tab assembly.

[0043] The above figures include the following reference numerals:

[0044] 10. Composite current collector; 11. First region; 12. Second region; 20. Electrode assembly; 21. First electrode; 211. First end; 22. Second electrode; 221. Second end; 201. First segment; 011. Third region; 012. Fourth region; 202. Second segment; 30. Adapter piece. Detailed Implementation

[0045] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0046] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0047] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings.

[0048] For the current electrode, from its top view, the composite current collector 10 includes a coated area and an uncoated area. The coated area means that the active material needs to be coated at this location. The uncoated area refers to the area where the active material does not need to be coated. This uncoated area is adjacent to the coated area and is located at the edge of the entire composite current collector 10. Then, the adapter piece 30 (i.e., the sheet required for cutting the tabs) is welded to connect the uncoated area. During the cell manufacturing process, most of the adapter piece 30 is cut off, thus forming a traditional rectangular tab structure. However, since the composite current collector 10 generates a higher temperature than the traditional metal current collector at the same battery rate, the tab width of the composite current collector 10 needs to be increased. The tabs of the traditional rectangular structure will be widened accordingly, which easily leads to an increase in the overall weight of the battery cell.

[0049] To address the aforementioned problems, the first embodiment of this utility model provides an electrode sheet, which includes a composite current collector 10, an active material layer, and an electrode tab assembly 20. Please refer to... Figures 1 to 6 Along the width direction of the composite current collector 10 (e.g.) Figure 1 (As indicated by arrow X), the composite current collector 10 includes an adjacent first region 11 and a second region 12. Along the thickness direction of the composite current collector 10, an active material layer is located on opposite sides of the composite current collector 10 and coated on the first region 11.

[0050] The electrode assembly 20 includes a first electrode 21 and a second electrode 22. Along the thickness direction of the composite current collector 10, the first electrode 21 and the second electrode 22 are respectively connected to the second region 12 and located on opposite sides of the composite current collector 10, so that the first electrode 21 and the second electrode 22 can respectively guide the current gathered on opposite sides of the electrode sheet to the battery terminal. Along the width direction of the composite current collector 10, the ends of the first electrode 21 and the second electrode 22 away from the first region 11 extend beyond the edge contour of the composite current collector 10, so that the first electrode 21 and the second electrode 22 can be connected to the terminal or connected to the terminal (such as the positive terminal or the negative terminal) through an adapter plate.

[0051] Among them, the first electrode 21 and the second electrode 22 have a length direction along the composite current collector 10 (e.g., Figure 1The width of the composite current collector 10 (in the direction indicated by the middle arrow Y) is such that, along the width direction of the composite current collector 10, the width of at least one of the first tab 21 and the second tab 22 on the side away from the second region 12 is smaller than the width on the side closer to the second region 12. In other words, the width of the portion where at least one of the first tab 21 and the second tab 22 (i.e., either the first tab 21 or the second tab 22, or both) connects to the second region 12 of the composite current collector 10 is larger, while the width of the portion away from the second region 12 is narrower. This reduces the weight of the electrode sheet and thus reduces the weight of the battery cell.

[0052] Meanwhile, before cutting out the first tab 21 and the second tab 22, the adapter piece 30 required to form the tab can be laid and welded to the second region 12 of the composite current collector 10 along the length direction of the composite current collector 10. Then, the required tab assembly 20 can be cut out in batches from the adapter piece 30, which is suitable for batch processing and is convenient and efficient.

[0053] As can be seen, in this embodiment, the composite current collector 10 of the electrode sheet has a first tab 21 and a second tab 22 respectively disposed on opposite sides, and the first tab 21 and the second tab 22 are respectively connected to the second region 12 of the composite current collector 10. Since the width of at least one of the first tab 21 and the second tab 22 on the side away from the second region 12 is smaller than the width on the side closer to the second region 12, at least one of the first tab 21 and the second tab 22 has a larger width in the second region 12 where the electrode sheet generates the most heat, so as to allow for a higher current to pass through (battery rate). On the other hand, the width of the portion of the first tab 21 and the second tab 22 away from the second region 12 is smaller. Since the current-carrying performance of the first tab 21 and the second tab 22 is better than that of the composite current collector 10, the portion with the smaller width of at least one of the first tab 21 and the second tab 22 will not significantly increase the electrode sheet temperature, but can significantly reduce the weight of the electrode sheet, thereby effectively reducing the overall weight of the battery cell and increasing the energy density of the cell.

[0054] The first electrode 21 and the second electrode 22 each include at least one segment 201 and a second segment 202. The first segment 201 covers and connects to the second region 12 to conduct the current collected by the composite current collector 10. Along the width direction of the composite current collector 10, the second segment 202 is located at the end of the first segment 201 away from the first region 11 and outside the edge contour of the composite current collector 10. Along the length direction of the composite current collector 10, the width of the second segment 202 is smaller than the width of the first segment 201.

[0055] Therefore, in this embodiment, at least one of the first tab 21 and the second tab 22 is connected to the second region 12. The first segment 201 is wider, while the second segment 202 is narrower. This can significantly reduce the weight of the battery cell without affecting the connection between the tab and the adapter board.

[0056] The first segment 201 includes a third region 011 and a fourth region 012. Along the width direction of the composite current collector 10, the third region 011 is located between the second segment 202 and the fourth region 012. Along the length direction of the composite current collector 10, the width of the third region 011 is not less than the width of the second segment 202 and less than the width of the fourth region 012. That is, the width of the third region 011 is between the width of the fourth region 012 and the width of the second segment 202. The third region 011 can further reduce the amount of tab material used, while also ensuring that the first segment 201 can carry a higher current, and ensuring that the first tab 21 and / or the second tab 22 have high structural strength, in conjunction with the fourth region 012.

[0057] The width of the third region 011 gradually increases towards the fourth region 012, which facilitates processing and cutting, and ensures that the overall width of the first segment 201 is not too narrow. The second segment 202 is rectangular, and the fourth region 012 of the first segment 201 can also be rectangular.

[0058] Along the length of the composite current collector 10, the edge contours of the third region 011 on both sides are arc-shaped. Specifically, they can be convex arcs protruding outwards in a direction away from the center of the third region 011 or concave arcs inwards. The concave arc shape (e.g.) Figure 2 When using the shape shown, not only can the width of the third region 011 be less than the width of the second segment 202, but the amount of material used in the first segment 201 can also be further reduced, thereby further reducing the weight of the battery cell. Of course, the edge contours of the third region 011 on both sides can also be diagonal lines, which makes cutting easier.

[0059] Along the width direction of the composite current collector 10, the length of the first segment 201 (e.g.) Figure 2 The length of the first segment 201 (as shown in L1) shall be no less than 0.5 mm and no more than 5 mm, thereby ensuring the connection strength between the tab assembly 20 and the composite current collector 10. The length of the first segment 201 may include one of the following: 0.5 mm, 0.8 mm, 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, 2.3 mm, 2.4 mm, 2.7 mm, 2.8 mm, 3 mm, 3.5 mm, 3.9 mm, 4 mm, 4.1 mm, 4.5 mm, 4.7 mm, 5 mm, or any other value between 0.5 mm and 5 mm.

[0060] Along the length direction of the composite current collector 10, the width of the first segment 201 (e.g.) Figure 2The width of the first segment 201 (as shown in K1) shall be no less than 10 mm and no more than 200 mm, so that the width of the first segment 201 is neither too small to conduct high current, nor too wide to result in insignificant weight reduction. The width of the first segment 201 may include one of the following: 10 mm, 15 mm, 18 mm, 20 mm, 26 mm, 30 mm, 34 mm, 38 mm, 40 mm, 60 mm, 80 mm, 100 mm, 110 mm, 150 mm, 170 mm, 200 mm, or any other value between 10 mm and 200 mm.

[0061] Along the width direction of the composite current collector 10, the length of the second segment 202 (e.g.) Figure 2 The length of the second segment 202 (as shown in L2) shall be no less than 10 mm and no more than 100 mm to securely connect the tab assembly 20 to the adapter plate. The length of the second segment 202 may be one of 10 mm, 20 mm, 25 mm, 30 mm, 36 mm, 40 mm, 42 mm, 48 mm, 50 mm, 70 mm, 75 mm, 80 mm, 86 mm, 90 mm, 93 mm, 98 mm, 100 mm, or any other value between 10 mm and 100 mm.

[0062] Along the length direction of the composite current collector 10, the width of the second segment 202 (e.g.) Figure 2 The width of the second segment 202 (as shown in K2) should be no less than 5mm and no more than 95mm, so that the width of the second segment 202 is not too narrow to facilitate current conduction and connection with the adapter board, nor should the width of the second segment 202 be too wide to result in insignificant weight reduction. The width of the second segment 202 may include one of the following: 5mm, 10mm, 16mm, 20mm, 30mm, 40mm, 60mm, 70mm, 80mm, 85mm, 90mm, 92mm, 95mm, or any other value between 5mm and 95mm.

[0063] In this embodiment, the thickness of the composite current collector 10 along its own thickness direction is not less than 2 μm (unit micrometer) and not greater than 20 μm. The thickness of the composite current collector 10 may include one of 2 μm, 3 μm, 5 μm, 8 μm, 10 μm, 12 μm, 15 μm, 17 μm, 20 μm, etc., or any other value between 2 μm and 20 μm.

[0064] Along the thickness direction of the composite current collector 10, the first tab 21 has a first thickness, and the second tab 22 has a second thickness. At least one of the first and second thicknesses is not less than 2 μm and not greater than 20 μm; that is, the first thickness is within this thickness range, or the thickness of the second tab 22 is within this thickness range, or both the thicknesses of the first tab 21 and the second tab 22 are within this thickness range. Within this thickness range, it can be ensured that the first tab 21 and the second tab 22 can better conduct the current collected by the composite current collector 10, without causing insignificant weight reduction due to excessive thickness. The magnitude of the first and / or second thickness may include one of the following: 2 μm, 3 μm, 4 μm, 5 μm, 5.6 μm, 8 μm, 10 μm, 11.5 μm, 12 μm, 15 μm, 17 μm, 20 μm, or any other value between 2 μm and 20 μm.

[0065] Both the first tab 21 and the second tab 22 include one of the following: copper tab, aluminum tab, titanium tab, and nickel tab. These types of tabs have good conductivity and excellent overcurrent performance.

[0066] Along the width direction of the composite current collector 10, both the first electrode tab 21 and the second electrode tab 22 have a first spacing (e.g., ...) between them and the first region 11. Figure 1 As shown), the first spacing is not less than 0.1 mm and not more than 2 mm. This can avoid the risk of short circuit between the tab and the active material layer, and can provide a certain operating space for the connection (such as welding) between each tab and the composite current collector 10, and can prevent the active material layer from being damaged and falling off.

[0067] The size of the first spacing may be one of 0.1mm, 0.5mm, 0.7mm, 1mm, 1.3mm, 1.4mm, 1.6mm, 1.8mm, 2mm, or any other value between 0.1mm and 2mm.

[0068] Along the thickness direction of the composite current collector 10, the projected outer contour of the first tab 21 coincides with the projected outer contour of the second tab 22, meaning the first tab 21 and the second tab 22 are positioned opposite each other. Both the first tab 21 and the second tab 22 have a wider side closer to the first region 11 and a narrower side farther from the first region 11, thus effectively reducing the weight of the electrode sheet. Furthermore, the oppositely positioned first tab 21 and second tab 22 can effectively conduct the current converging on opposite sides of the composite current collector 10 and reduce the space occupied by the tab assembly 20 on the electrode sheet.

[0069] like Figure 3As shown, in some embodiments, a second gap exists between the second segment 202 of the first tab 21 and the second segment 202 of the second tab 22 along the thickness direction of the composite current collector 10. In this case, the second segments 202 of the first tab 21 and the second tab 22 can be welded together with the adapter plate, respectively.

[0070] like Figure 4 As shown, in some embodiments, along the width direction of the composite current collector 10, the ends of the second segments 202 of the first electrode 21 and the second electrode 22, away from the first segment 201, are connected to each other. This allows the interconnected first electrode 21 and the second electrode 22 to be simultaneously welded to the adapter plate, facilitating processing.

[0071] In some embodiments, along the width direction of the composite current collector 10, the first electrode tab 21 includes a first end 211 away from the first region 11, and the second electrode tab 22 includes a second end 221 away from the first region 11. For example, Figure 5 As shown, the first end 211 is connected to the second tab 22. Along the width direction of the composite current collector 10, the first end 211 is located between the edge contour of the second region 12 and the second end 221. Therefore, the second segment 202 of the first tab 21 can be bent so that its first end 211 is welded to the second segment 202 of the second tab 22. Then, the second segment 202 of the second tab 22 is welded to the adapter plate.

[0072] Or, such as Figure 6 As shown, the second end 221 is connected to the first tab 21. Along the width direction of the composite current collector 10, the second end 221 is located between the edge contour of the second region 12 and the first end 211. Thus, the second segment 202 of the second tab 22 can be bent so that its second end 221 is welded to the first tab 21. Then, the second segment 202 of the first tab 21 is welded to the adapter plate.

[0073] The first tab 21 and the second tab 22 can all be connected to the adapter plate by welding and fixing. The first tab 21 and the second tab 22 can reduce the weight of the electrode sheet while ensuring good connection strength between the tab assembly 20 and the adapter plate.

[0074] The composite current collector 10 in this embodiment includes a substrate layer and a conductive layer. The thickness of the substrate layer along its own thickness direction is not less than 3 μm and not more than 8 μm. This thickness can greatly reduce the mass of the composite current collector 10, while preventing the substrate layer from being torn during the coating process due to excessive thinness. A conductive layer is provided on both opposite sides of the substrate layer along its thickness direction. An active material layer is located on the surface of the conductive layer away from the substrate layer. The first tab 21 and the second tab 22 are respectively connected to the portions of the conductive layer located in the second region 12, so that the first tab 21 and the second tab 22 can conduct electricity with the conductive layer.

[0075] The conductive layer (also called the current-converging layer) in this embodiment includes any material that can be disposed on the substrate layer to help converge current. That is, the conductive layer can consist of only one material, such as a pure copper layer or an aluminum layer. Alternatively, the conductive layer can be a pure alloy, such as a copper alloy layer, an aluminum alloy layer, a nickel alloy layer, or a titanium alloy layer. The conductive layer can also include a multi-layer structure. For example, the first layer may be a material that improves the adhesion between the current-converging layer and the substrate layer, such as an alumina layer, a nickel-copper layer, a titanium-copper layer, or other nickel alloy layers, titanium alloy layers, copper alloy layers, or aluminum alloy layers. Of course, other materials can also be used; there are no limitations here. Furthermore, in some other embodiments, a protective layer may be disposed on the outermost surface of the conductive layer to prevent oxidation and corrosion.

[0076] The substrate layer may include one of the following layers: polyethylene layer, polypropylene layer, ethylene-propylene copolymer layer, polyethylene terephthalate layer, polyethylene terephthalate layer, poly(p-phenylene terephthalate) layer, acrylonitrile-butadiene-styrene copolymer layer, poly(p-phenylene terephthalate) layer, polypropylene layer, polyoxymethylene layer, epoxy resin layer, phenolic resin layer, polytetrafluoroethylene layer, polyvinylidene fluoride layer, silicone rubber layer, and polycarbonate layer. Preferably, the substrate layer is made of polypropylene because it is resistant to most acids and alkalis, which can greatly improve the lifespan of the composite current collector 10.

[0077] The active material layer in this embodiment may include a positive active material layer composed of a positive active material and a negative active material layer composed of a negative active material. The structure of a battery (such as a lithium battery) may include a positive electrode, a negative electrode, a separator, and an electrolyte, which are conventional and will not be described further here.

[0078] The electrode preparation method in this embodiment can be described by the following steps:

[0079] First, a substrate layer is taken, and then the substrate layer is unwound and placed into a vacuum coating device (such as magnetron sputtering or vacuum evaporation). A conductive layer is formed on the substrate layer by one or more deposition processes. Then, an active material layer is coated on the first region 11 of the conductive layer. For the active material layer, if it is a negative electrode current collector, a negative electrode active material is coated; if it is a positive electrode current collector, a positive electrode active material is coated. Then, a connecting piece is soldered onto the second region 12. Figure 7 As shown, the connecting piece completely covers the second region 12 without the active material layer and is separated from the first region 11 by a first spacing. The connecting piece is then cut into the shape shown. Figure 1 The shapes of the first tab 21 and / or the second tab 22 shown can be used to batch process and cut the tab assembly 20, making the processing convenient and efficient.

[0080] The second embodiment of this utility model also provides a battery, which includes electrodes. The structure of the electrodes is described in the first embodiment of this utility model, and will not be repeated here.

[0081] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0082] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0083] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A pole piece, characterized in that, include: The composite current collector (10) includes an adjacent first region (11) and a second region (12) along the width direction of the composite current collector (10); An active material layer is located on opposite sides of the composite current collector (10) and coated on the first region (11) along the thickness direction of the composite current collector (10). A tab assembly (20) includes a first tab (21) and a second tab (22). Along the thickness direction of the composite current collector (10), the first tab (21) and the second tab (22) are respectively connected to the second region (12) and are respectively located on opposite sides of the composite current collector (10). Along the width direction of the composite current collector (10), the ends of the first tab (21) and the second tab (22) away from the first region (11) extend to the edge contour of the composite current collector (10). The first electrode (21) and the second electrode (22) have widths along the length direction of the composite current collector (10). Along the width direction of the composite current collector (10), at least one of the first electrode (21) and the second electrode (22) has a width on the side away from the second region (12) that is smaller than the width on the side closer to the second region (12).

2. The pole piece of claim 1, wherein At least one of the first electrode tab (21) and the second electrode tab (22) includes: The first segment (201) covers the second region (12) and is connected to the second region (12); The second segment (202) is located at the end of the first segment (201) away from the first region (11) and outside the edge contour of the composite current collector (10) along the width direction of the composite current collector (10). The width of the second segment (202) is smaller than the width of the first segment (201) along the length direction of the composite current collector (10).

3. The pole piece of claim 2, wherein The first segment (201) includes a third region (011) and a fourth region (012). Along the width direction of the composite current collector (10), the third region (011) is located between the second segment (202) and the fourth region (012). Along the length direction of the composite current collector (10), the width of the third region (011) is not less than the width of the second segment (202) and less than the width of the fourth region (012).

4. The pole piece of claim 3, wherein The width of the third region (011) gradually increases toward the fourth region (012); and / or, Along the length of the composite current collector (10), the edge contours of the third region (011) on both sides are arc-shaped.

5. The pole piece of claim 2, wherein Along the width direction of the composite current collector (10), the length of the first segment (201) is not less than 0.5 mm and not more than 5 mm; and / or, Along the length of the composite current collector (10), the width of the first segment (201) is not less than 10 mm and not more than 200 mm; and / or, Along the width direction of the composite current collector (10), the length of the second segment (202) is not less than 10 mm and not more than 100 mm; and / or, Along the length of the composite current collector (10), the width of the second segment (202) is not less than 5 mm and not more than 95 mm; and / or, The thickness of the composite current collector (10) is not less than 2 μm and not more than 20 μm.

6. The pole piece according to any one of claims 1 to 5, characterized in that Along the thickness direction of the composite current collector (10), the first tab (21) has a first thickness, and the second tab (22) has a second thickness, wherein at least one of the first thickness and the second thickness is not less than 2 μm and not greater than 20 μm; and / or, The first electrode (21) and the second electrode (22) each include one of the following: copper electrode, aluminum electrode, titanium electrode, and nickel electrode.

7. The pole piece according to any one of claims 1 to 5, characterized in that Along the width direction of the composite current collector (10), both the first tab (21) and the second tab (22) have a first distance from the first region (11), the first distance being not less than 0.1 mm and not greater than 2 mm.

8. The pole piece according to any one of claims 2 to 5, characterized in that Along the thickness direction of the composite current collector (10), the projected outer contour of the first tab (21) coincides with the projected outer contour of the second tab (22); and / or, Along the thickness direction of the composite current collector (10), there is a second spacing between the second segment (202) of the first tab (21) and the second segment (202) of the second tab (22); or, Along the width direction of the composite current collector (10), the ends of the second segments (202) of both the first electrode (21) and the second electrode (22) that are away from the first segment (201) are connected to each other; or, Along the width direction of the composite current collector (10), the first electrode tab (21) includes a first end (211) away from the first region (11), and the second electrode tab (22) includes a second end (221) away from the first region (11); wherein: The first end (211) is connected to the second tab (22), and along the width direction of the composite current collector (10), the first end (211) is located between the edge contour of the second region (12) and the second end (221), or, The second end (221) is connected to the first tab (21) along the width direction of the composite current collector (10), and the second end (221) is located between the edge contour of the second region (12) and the first end (211).

9. The pole piece according to any one of claims 1 to 5, characterized in that The composite current collector (10) includes: A substrate layer, wherein the thickness of the substrate layer along its own thickness direction is not less than 3 μm and not more than 8 μm; The conductive layer is provided on both opposite sides of the substrate layer along the thickness direction of the substrate layer. The active material layer is located on the surface of the conductive layer away from the substrate layer. The first tab (21) and the second tab (22) are respectively connected to the portion of the conductive layer located in the second region (12).

10. A battery, characterized by Includes the electrode sheet as described in any one of claims 1 to 9.

Images