Pole piece, battery module and electronic device

Abstract

The application discloses a pole piece, a battery module and an electronic device, and belongs to the technical field of battery modules. The pole piece comprises a current collector, a slurry layer, a metal sheet and a pole lug. The current collector comprises a body and a connecting part, the body is provided with a notch, and the connecting part is arranged along the edge of the notch; the slurry layer is arranged on the surface of the body, and the connecting part is exposed from the slurry layer; the metal sheet is arranged at the notch and connected with the connecting part; and the pole lug is connected with the metal sheet.

Description

Technical Field

[0001] This application belongs to the field of battery module technology, specifically relating to an electrode, a battery module, and an electronic device. Background Technology

[0002] In related technologies, the electrode plates of a battery module include a current collector and tabs. The current collector includes a substrate and a metal layer, with the metal layer disposed on the surface of the substrate, and the tabs welded to the metal layer. However, because the metal layer of the current collector is relatively thin, the connection strength between the tab and the current collector is low after the tab is welded to the metal layer, reducing the stability of the battery module during use. Utility Model Content

[0003] This application aims to provide an electrode, battery module, and electronic device that at least solves one of the problems of low connection strength between the electrode and the current collector after the electrode tab is welded to the metal layer, which reduces the stability of the battery module during use.

[0004] To solve the above-mentioned technical problems, this application is implemented as follows:

[0005] In a first aspect, embodiments of this application provide an electrode sheet, comprising a current collector, a slurry layer, a metal sheet, and a tab. The current collector includes a body and a connecting portion, the body having a notch, and the connecting portion being arranged along the edge of the notch; the slurry layer is disposed on the surface of the body, and the connecting portion is exposed outside the slurry layer; the metal sheet is disposed at the notch and connected to the connecting portion; the tab is connected to the metal sheet.

[0006] Secondly, embodiments of this application propose a battery module including electrode sheets as described in any of the above technical solutions.

[0007] Thirdly, embodiments of this application propose an electronic device including a battery module as described in any of the above technical solutions.

[0008] In embodiments of this application, the electrode includes a current collector for collecting and conducting current. The current collector includes a body and a connecting portion. The body has a notch, and the connecting portion is arranged along the edge of the notch, i.e., the current collector has a connecting portion at the notch. The electrode also includes a slurry layer and a metal sheet. The slurry layer is disposed on the surface of the body, the connecting portion is exposed outside the slurry layer, and the metal sheet is disposed at the notch and connected to the connecting portion, thereby achieving an electrical connection between the metal sheet and the current collector. Because the connecting portion is exposed outside the slurry layer, the influence of the slurry layer on the connection between the metal sheet and the connecting portion is reduced, resulting in a tighter contact between the metal sheet and the connecting portion, thereby increasing the conductive area between the metal sheet and the connecting portion and reducing the impedance between the metal sheet and the connecting portion. The electrode also includes a tab connected to the metal sheet, i.e., the tab is connected to the current collector through the metal sheet. The metal sheet has a thicker metal layer than the surface of the current collector, thereby resulting in a higher connection strength between the tab and the metal sheet, a more stable connection between the tab and the current collector, and improved stability of the battery module during use.

[0009] The tabs are connected to the current collector via metal plates, increasing the conductive area between the tabs and the current collector and reducing the impedance between them. During battery module operation, the reduced impedance at the connection point between the tabs, metal plates, and tabs results in less heat generation, further improving the stability of the battery module. This lower heat generation also leads to a smaller temperature rise during battery module operation, resulting in better charge and discharge performance, thus improving energy storage efficiency and overall battery quality. Finally, the lower temperature rise extends the battery module's lifespan, further enhancing its overall quality and providing a better user experience when using electronic devices with battery modules.

[0010] Since the battery module includes the electrode sheet of any of the above technical solutions, the battery module has all the beneficial effects of the electrode sheet of any of the above technical solutions, which will not be repeated here.

[0011] Since the electronic device includes a battery module as described in any of the above technical solutions, the electronic device possesses all the beneficial effects of the battery module as described in any of the above technical solutions, which will not be elaborated further here.

[0012] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0013] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0014] Figure 1 This is one of the schematic diagrams of an electrode sheet according to an embodiment of this application;

[0015] Figure 2 This is a second schematic diagram of an electrode sheet according to an embodiment of this application;

[0016] Figure 3 This is one of the schematic diagrams of side A of the electrode sheet according to an embodiment of this application;

[0017] Figure 4 This is one of the schematic diagrams of side B of the electrode sheet according to an embodiment of this application;

[0018] Figure 5 This is a third schematic diagram of the electrode sheet according to an embodiment of this application;

[0019] Figure 6 This is a partial schematic diagram of the electrode sheet according to an embodiment of this application;

[0020] Figure 7 This is a schematic diagram of a current collector according to an embodiment of this application;

[0021] Figure 8 This is one of the schematic diagrams illustrating the processing of an electrode sheet according to an embodiment of this application;

[0022] Figure 9 This is a second schematic diagram of the electrode processing procedure according to an embodiment of this application;

[0023] Figure 10 This is a third schematic diagram of the electrode processing procedure according to an embodiment of this application;

[0024] Figure 11 This is a second schematic diagram of side A of the electrode sheet according to an embodiment of this application;

[0025] Figure 12 This is a second schematic diagram of side B of the electrode sheet according to an embodiment of this application.

[0026] Figure label:

[0027] 100 Current collector, 110 Notch, 120 Connector, 130 Substrate, 140 First metal layer, 150 Second metal layer, 160 Body, 200 Slurry layer, 300 Metal sheet, 400 Tab, 500 Conductive adhesive, 600 Conductive component, 700 Green adhesive. Detailed Implementation

[0028] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0029] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0030] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0031] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0032] The following is combined with Figures 1 to 12 This application describes electrode sheets, battery modules, and electronic devices according to embodiments thereof.

[0033] like Figure 1 and Figure 2As shown, an electrode sheet according to some embodiments of this application includes a current collector 100, a slurry layer 200, a metal sheet 300, and a tab 400. The current collector 100 includes a body 160 and a connecting portion 120. The body 160 is provided with a notch 110, and the connecting portion 120 is arranged along the edge of the notch 110. The slurry layer 200 is disposed on the surface of the body 160, and the connecting portion 120 is exposed outside the slurry layer 200. The metal sheet 300 is disposed at the notch 110 and connected to the connecting portion 120. The tab 400 is connected to the metal sheet 300.

[0034] In this embodiment, the electrode includes a current collector 100 for collecting and conducting current. The current collector 100 includes a body 160 and a connecting portion 120. The body 160 is provided with a notch 110, and the connecting portion 120 is arranged along the edge of the notch 110, that is, the current collector 100 is provided with a connecting portion 120 at the notch 110. The electrode also includes a slurry layer 200 and a metal sheet 300. The slurry layer 200 is disposed on the surface of the body 160, and the connecting portion 120 is exposed outside the slurry layer 200. The metal sheet 300 is disposed at the notch 110 and connected to the connecting portion 120, thereby realizing the electrical connection between the metal sheet 300 and the current collector 100. Since the connecting portion 120 is exposed outside the slurry layer 200, the influence of the slurry layer 200 on the connection between the metal sheet 300 and the connecting portion 120 is reduced, making the contact between the metal sheet 300 and the connecting portion 120 tighter, thereby increasing the conductive area between the metal sheet 300 and the connecting portion 120 and reducing the impedance between the metal sheet 300 and the connecting portion 120. The electrode also includes a tab 400, which is connected to a metal sheet 300. That is, the tab 400 is connected to the current collector 100 through the metal sheet 300. The metal sheet 300 has a thicker metal layer than the surface of the current collector 100, which makes the connection between the tab 400 and the metal sheet 300 stronger and the connection between the tab 400 and the current collector 100 more stable, thus improving the stability of the battery module during use.

[0035] Optionally, the main body 160 and the connecting part 120 are integrally connected.

[0036] The tab 400 is connected to the current collector 100 via the metal plate 300, resulting in a larger conductive area between the tab 400 and the current collector 100, thus reducing the impedance between them. During battery module operation, because the connection between the tab 400 and the current collector 100 via the metal plate 300 reduces the impedance, less heat is generated at the connection point of the current collector 100, metal plate 300, and tab 400, further improving the stability of the battery module during operation. Furthermore, the lower heat generation at the connection point of the current collector 100, metal plate 300, and tab 400 also results in a lower temperature rise during battery module operation, leading to better charge and discharge performance, improved energy storage efficiency, and enhanced battery module quality. The lower temperature rise during battery module operation also extends its lifespan, further improving its quality and providing users with a better experience when using electronic devices with battery modules.

[0037] Specifically, compared to the tab 400 being directly connected to the current collector 100, the tab 400 is connected to the current collector 100 via a metal sheet 300. The conductive area between the metal sheet 300 and the current collector 100 is larger, resulting in a higher connection strength between them. Furthermore, the connection between the tab 400 and the metal sheet 300 is also stronger due to the greater thickness of the metal sheet 300. Given the high connection strength between the metal sheet 300 and the current collector 100, and the high connection strength between the tab 400 and the metal sheet 300, the connection strength between the tab 400 and the current collector 100 is also significantly higher.

[0038] The tab 400 is welded to the metal sheet 300. After welding, the welding pull between the tab 400 and the metal sheet 300 is greater than or equal to 15N, realizing high-strength single-point welding of the current collector 100 in the tab 400-centered (MMT) structure.

[0039] Compared to a direct connection between the tab 400 and the current collector 100, the tab 400 is connected to the current collector 100 via a metal plate 300. This connection provides a larger conductive area between the metal plate 300 and the current collector 100, resulting in lower impedance between them. Furthermore, since the metal plate 300 lacks a slurry layer 200, there is no obstruction between the tab 400 and the metal plate 300, leading to a tighter contact and further lower impedance. Because both the metal plate 300 and the current collector 100 have lower impedance, the heat generated between the tab 400 and the current collector 100 during battery module operation is also reduced, thus minimizing the temperature rise of the battery module during operation.

[0040] Compared to the tab 400 being directly connected to the current collector 100, the tab 400 is connected to the current collector 100 through the metal sheet 300. The slurry layer 200 is no longer provided between the tab 400 and the metal sheet 300, thereby reducing the impact of the slurry layer 200 on the connection strength and conductive area.

[0041] Compared to multi-tab winding (MTW) ​​structures, the electrode sheet provided in this application has a simpler manufacturing process and lower processing costs. Furthermore, the welding area between the tab 400 and the current collector 100 occupies less space in the Y direction, increasing the volumetric energy density of the battery module. Additionally, the stress distribution at the welding position of the tab 400 is more uniform, making the tab 400 less prone to inverted insertion or breakage, thus reducing the probability of tab 400 failure.

[0042] Optionally, the current collector 100 is a composite aluminum current collector (APF, Aluminum Polymer Foil).

[0043] Metal sheet 300 is either aluminum foil or copper foil.

[0044] The electrode is either the positive electrode or the negative electrode of the battery module.

[0045] After the active material and auxiliary material of the battery electrode are mixed, a solid coating, called slurry layer 200, is firmly attached to the metal foil of the current collector 100 by a coating process.

[0046] Optionally, the notch 110 is provided at the edge in the width direction of the body 160, and one side of the notch 110 is not closed.

[0047] The notch 110 can also be located in the middle of the width direction of the body 160, and the notch 110 is closed on all sides.

[0048] Optionally, tab 400 is welded to metal sheet 300.

[0049] Optionally, the electrode is made of copper foil (Cu Foil).

[0050] According to some embodiments of this application, such as Figure 2 , Figure 3 and Figure 4 As shown, there are at least two metal sheets 300, which are respectively disposed on both sides of the connecting part 120, and a portion of the at least two metal sheets 300 are in contact with each other.

[0051] In this embodiment, at least two metal sheets 300 are respectively disposed on both sides of the connecting portion 120, with partial areas of the at least two metal sheets 300 in contact. This clamps the connecting portion 120 with the at least two metal sheets 300, further enhancing the connection strength between the metal sheets 300 and the connecting portion 120. Furthermore, the partial contact of the at least two metal sheets 300 results in a greater thickness for the metal sheets 300, leading to higher strength after the tab 400 is connected to the metal sheets 300. This further enhances the connection strength between the tab 400 and the current collector 100, improving the stability of the connection between them. The fact that at least two metal sheets 300 are respectively disposed on both sides of the connecting portion 120, with partial areas of the at least two metal sheets 300 in contact, allows the tab 400 to simultaneously conduct with the metal layers on both sides of the current collector 100, further reducing the impedance between the tab 400 and the current collector 100. This reduces the heat generated by the tab 400 and the current collector 100 during battery module operation, improving the quality of the battery module.

[0052] Optionally, there are two metal sheets 300, which are respectively disposed on both sides of the connecting portion 120, that is, one metal sheet 300 is disposed on each side of the connecting portion 120. The two metal sheets 300 are in contact with the notch 110 at the opposite positions.

[0053] There are three metal sheets 300, which are respectively disposed on both sides of the connecting portion 120. Specifically, one metal sheet 300 is disposed on the first side of the connecting portion 120, and two metal sheets 300 are disposed on the second side of the connecting portion 120. The two metal sheets on the second side of the connecting portion 120 are stacked or arranged side-by-side. When the two metal sheets 300 on the second side of the connecting portion 120 are stacked, the first metal sheet 300 that contacts the connecting portion 120 partially contacts the metal sheet 300 on the first side of the connecting portion 120, and the second metal sheet 300 is located on the side of the first metal sheet 300 away from the connecting portion 120. When the metal sheets 300 on the second side of the connecting portion 120 are arranged side-by-side, the two metal sheets 300 are combined and connected to the connecting portion 120, and partial areas of the two metal sheets 300 contact the metal sheet 300 on the first side of the connecting portion 120.

[0054] The number of metal sheets 300 is four, with two metal sheets 300 on each side of the connecting part 120; or one metal sheet 300 is provided on the first side of the connecting part 120 and three metal sheets 300 are provided on the second side of the connecting part 120.

[0055] According to some embodiments of this application, such as Figure 2 As shown, the electrode also includes conductive adhesive 500, which is disposed between the metal sheet 300 and the connecting portion 120 for connecting the metal sheet 300 and the connecting portion 120.

[0056] In this embodiment, the electrode also includes conductive adhesive 500, which is disposed between the metal sheet 300 and the connecting portion 120. The metal sheet 300 is fixed to the connecting portion 120 by the conductive adhesive 500, thereby improving the reliability of the connection between the metal sheet 300 and the connecting portion 120.

[0057] Optionally, conductive adhesive 500 is disposed between the metal sheet 300 and the connecting portion 120, and conductive adhesive 500 is disposed between at least two metal sheets 300. At least two metal sheets 300 are bonded and fixed by conductive adhesive 500, further improving the connection strength between the metal sheet 300 and the current collector 100.

[0058] Optionally, the metal sheet 300 is cut into a square shape, with the same size as the notch 110 after cleaning the current collector 100. The exposed portion of the current collector 100 in the notch 110 is coated with conductive adhesive 500 on both sides. The two square metal sheets 300 are then glued to the A and B sides of the notch 110 in the current collector 100, respectively. After being embedded in the notch 110, pressure is applied to cure the two metal sheets 300, ensuring they are fully bonded together.

[0059] According to some embodiments of this application, such as Figure 5 and Figure 6 As shown, there is one metal sheet 300, which is disposed on one side of the connecting part 120.

[0060] In this embodiment, the number of metal sheets 300 is one. The metal sheet 300 is disposed on one side of the connecting part 120. While realizing the connection between the tab 400 and the current collector 100, it reduces the space occupied by the metal sheet 300 in the thickness direction of the electrode, thereby reducing the volume of the battery module and increasing the volumetric energy density of the battery module.

[0061] Optionally, a metal sheet 300 may be disposed on the first side of the connecting portion 120 or on the second side of the connecting portion 120.

[0062] Optionally, the thickness direction is Figure 2 The direction indicated by the middle arrow Y.

[0063] According to some embodiments of this application, such as Figure 5 and Figure 6 As shown, the electrode also includes a conductive component 600, which is connected to the metal sheet 300 and extends through the connecting portion 120 along the thickness direction of the current collector 100.

[0064] In this embodiment, the conductive component 600 is connected to the metal sheet 300 and extends through the connecting portion 120 along the thickness direction of the current collector 100. While fixing the metal sheet 300 and the current collector 100, it enables the metal layers on both sides of the current collector 100 to conduct electricity. This allows the tab 400 to be electrically connected to the metal layers on both sides of the current collector 100 through the metal sheet 300, further reducing the impedance between the tab 400 and the current collector 100. Consequently, it reduces the heat generated by the tab 400 and the current collector 100 during the operation of the battery module, thereby improving the quality of the battery module.

[0065] Optionally, the metal sheet 300 is welded to the connecting part 120.

[0066] According to some embodiments of this application, such as Figure 1 , Figure 2 and Figure 7 As shown, the current collector 100 includes a substrate 130, a first metal layer 140, and a second metal layer 150; the first metal layer 140 is disposed on one side of the substrate 130 and connected to the metal sheet 300; the second metal layer 150 is disposed on the other side of the substrate 130; the conductive component 600 passes through the first metal layer 140, the substrate 130, and the second metal layer 150, and both ends of the conductive component 600 are connected to the first metal layer 140 and the second metal layer 150, respectively.

[0067] In this embodiment, the current collector 100 includes a substrate 130, a first metal layer 140, and a second metal layer 150. The first metal layer 140 is disposed on one side of the substrate 130 and connected to the metal sheet 300. The second metal layer 150 is disposed on the other side of the substrate 130. The substrate 130 is used to support the first metal layer 140 and the second metal layer 150. The first metal layer 140 and the second metal layer 150 can transmit current simultaneously, thereby realizing the transmission of electrical energy. The conductive component 600 penetrates the first metal layer 140, the substrate 130, and the second metal layer 150, with both ends of the conductive component 600 connected to the first metal layer 140 and the second metal layer 150 respectively. This allows the first metal layer 140 and the second metal layer 150 to be connected via the conductive component 600, enabling the metal sheet 300 connected to the conductive component 600 to be electrically connected to both the first metal layer 140 and the second metal layer 150 simultaneously. This further reduces the impedance between the tab 400 and the current collector 100, thereby reducing the heat generated by the tab 400 and the current collector 100 during battery module operation and improving the quality of the battery module. Furthermore, the conductive component 600, which penetrates the first metal layer 140, the substrate 130, and the second metal layer 150 and is simultaneously connected to both, can be formed synchronously during the welding of the metal sheet 300. This simplifies the connection process between the metal sheet 300 and the current collector 100, reduces the manufacturing difficulty of the electrode, and improves the manufacturing efficiency of the electrode.

[0068] Optionally, both the body 160 and the connecting portion 120 include a substrate 130, a first metal layer 140, and a second metal layer 150.

[0069] Optionally, the body 160 includes a substrate 130, a first metal layer 140 and a second metal layer 150, and the connecting portion 120 includes the first metal layer 140 and / or the second metal layer 150.

[0070] Alternatively, the metal layer may be an aluminum layer or a copper layer.

[0071] When the electrode is a positive electrode, the current collector 100 is a composite aluminum current collector, the first metal layer 140 and the second metal layer 150 are aluminum layers, and the metal sheet 300 is an aluminum foil sheet.

[0072] When the electrode is a negative electrode, the current collector 100 is a composite copper current collector (CPF), the first metal layer 140 and the second metal layer 150 are copper layers, and the metal sheet 300 is a copper foil.

[0073] Optionally, the area where the metal sheet 300 overlaps with the connecting part 120 is welded using multi-point micro-penetration welding. High-energy laser pulses penetrate the second metal layer 150 and the substrate 130 to form a micron-level through hole. The laser continues to penetrate, melting the first metal layer 140 and the metal sheet 300, and forming a molten metal pool in the hole. After the molten metal pool solidifies, it forms a conductive component 600, ensuring that the welding needle penetrates the substrate 130, the first metal layer 140 and the second metal layer 150 of the current collector 100 to form a vertical conductive channel and achieve double-sided conductivity.

[0074] According to some embodiments of this application, such as Figure 1 and Figure 2 As shown, the electrode is projected along the thickness direction of the current collector 100, and the projection of the tab 400 at least partially overlaps with the projection of the notch 110.

[0075] In this embodiment, the electrode is projected along the thickness direction of the current collector 100, and the projection of the tab 400 at least partially overlaps with the projection of the notch 110, so that the electrode can occupy the space of the notch 110, thereby reducing the space occupied by the tab 400 in the thickness direction of the electrode, reducing the volume of the battery module, and increasing the density of the battery module.

[0076] According to some embodiments of this application, such as Figure 2 As shown, the metal sheet 300 covers the notch 110 and is attached to one side of the connecting portion 120.

[0077] In this embodiment, the metal sheet 300 covers the notch 110 and is attached to one side of the connecting portion 120, thereby increasing the area of ​​the electrode and further enhancing the connection strength between the electrode and the current collector 100.

[0078] According to some embodiments of this application, such as Figure 1 As shown, the tab 400 is closer to the middle of the current collector 100 than the end and middle of the current collector 100.

[0079] In this embodiment, the tab 400 is closer to the middle of the current collector 100 than the end and middle of the current collector 100, that is, the tab 400 is placed in the middle, which shortens the maximum movement path of electrons on the electrode, thereby reducing the internal resistance of the battery module, increasing the volumetric energy density of the battery module, and reducing the heat generated during the operation of the battery module, thereby reducing the temperature rise of the battery module.

[0080] Specifically, compared to the multi-tab winding structure (MTW), eliminating the head junction welding area of ​​the multi-tab winding structure increases the volumetric energy density of the battery module by about 10%.

[0081] According to some embodiments of this application, the electrode is a positive electrode, the metal sheet 300 is aluminum foil, and the electrode manufacturing process includes the following steps:

[0082] Step 1, processing of gap 110: (e.g.) Figure 8 As shown, the positive electrode slurry is first coated onto the current collector 100. Figure 9 As shown, the tab 400 position is then cleaned using a laser to remove the slurry and expose the current collector 100. Figure 10 As shown, the substrate 130 of the current collector 100 at the welding position of the tab 400 is then removed by laser precision cutting, leaving a rectangular notch 110. The current collector 100 around the notch 110 needs to be empty as a connection part 120.

[0083] Specifically, such as Figure 11 and Figure 12 As shown, the electrode is a positive electrode, and the current collector 100 is a composite aluminum current collector. The total length of the electrode is 1478.8 mm, of which the length G of the coated area on side A is 1437 mm, and the length H of the uncoated area on side A is 41.8 mm; the length I of the coated area on side B is 1309 mm, and the length J of the uncoated area on side B is 169.8 mm. A groove is created using laser cleaning, with the groove position positioned relative to the coated area on side A at a distance of 468 mm. The groove length F is 22.5 mm, and the width C is 20 mm. Then, a square notch 110 with a length E of 15 mm and a width D of 10 mm is cut in the middle of the groove using a laser cutting machine.

[0084] Step 2, aluminum foil lamination:

[0085] Aluminum foil composite solution 1: such as Figure 3 and Figure 4 As shown, the aluminum foil is cut into square pieces, the size of which matches the size of the notch 110 after cleaning the current collector 100. The exposed portion of the current collector 100 at the notch 110 is coated with conductive adhesive 500 (conductivity ≥ 10). 4 (S / M) The two square aluminum foil pieces are glued to the A and B sides of the pre-reserved notch 110 of the current collector 100, respectively. After embedding into the notch 110, pressure is applied to cure, so that the two aluminum foils are fully bonded together.

[0086] Specifically, conductive adhesive 500 is applied to both sides of the exposed current collector 100 in the slot. Two aluminum foils, each 22.5 mm long, 20 mm wide, and 4 μm thick, are then attached to the A and B sides of the reserved slot in the current collector 100, respectively. After being embedded in the slot, they are pressed and cured at a pressure of 0.3 MPa for 5 seconds to ensure that the two aluminum foils are fully bonded together.

[0087] Aluminum foil composite scheme two: Cut the aluminum foil into square sheets and overlap them with notch 110. Use multi-point micro-penetration welding in the overlapping area. High-energy laser pulses penetrate the upper aluminum and polymer to form micron-level through holes. The laser continues to penetrate and melt the lower aluminum and square sheet aluminum foil, forming a molten metal pool in the hole. After the molten pool solidifies, it forms a metallized through hole, ensuring that the welding needle penetrates the surface metal of current collector 100 → polymer layer → bottom metal to form a vertical conductive channel and achieve double-sided conductivity.

[0088] Specifically, the aluminum foil thickness is 8μm.

[0089] Step 3: Soldering the tabs to 400mm and applying 700mm green adhesive:

[0090] like Figure 1 As shown, the tab 400 is welded onto the aluminum foil using ultrasonic welding or laser welding. In the first method described above, the tab 400 and both layers of aluminum foil must be welded together to achieve double-sided conductivity. After welding, the welding pull force must be greater than 12N, the effective welding area greater than 70%, and there must be no incomplete or false welds. After welding the tab 400, green adhesive 700 must be applied to both sides of the welding position to prevent burrs from penetrating the separator and causing a short circuit in the battery.

[0091] Specifically, apply 25mm×25mm green adhesive 700 to both sides of slots A and B.

[0092] Experiments showed that the electrode sheet manufactured using aluminum foil composite scheme one had a welding tensile strength of more than 15N for the 400mm electrode tab.

[0093] The electrode sheet manufactured using aluminum foil composite scheme two has a welding tensile strength of more than 14N for the 400 electrode tabs.

[0094] In related technologies, the welding pull force for tab 400 is 5N.

[0095] The electrode tab 400 provided in this application has significantly improved welding pull force, solving the bottleneck of welding composite aluminum current collectors.

[0096] The battery module according to some embodiments of this application includes the electrode sheet as described in any of the above embodiments. Since the battery module includes the electrode sheet as described in any of the above embodiments, the battery module has all the beneficial effects of the electrode sheet as described in any of the above embodiments, which will not be repeated here.

[0097] Optionally, the positive electrode sheet is any of the electrodes in the above embodiments. The positive electrode sheet and the negative electrode sheet are used to prepare a bare cell through a winding structure. The bare cell is then packaged, injected with electrolyte, and formed into a battery module.

[0098] Optionally, the negative electrode sheet is any of the electrodes in the above embodiments, and the positive and negative electrode sheets are used to prepare a bare cell through a winding structure. The bare cell is then packaged, injected with electrolyte, and formed into a battery module.

[0099] An electronic device according to some embodiments of this application includes a battery module as described in any of the above embodiments. Since the electronic device includes a battery module as described in any of the above embodiments, it possesses all the beneficial effects of the battery module as described in any of the above embodiments, which will not be elaborated further here.

[0100] Alternatively, the electronic device includes a mobile phone, tablet, smart wearable device, e-reader, or laptop.

[0101] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0102] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. An electrode sheet, characterized in that, include: A current collector includes a body and a connecting part, the body having a notch, and the connecting part being arranged along the edge of the notch; A slurry layer is disposed on the surface of the body, and the connecting portion is exposed outside the slurry layer; A metal sheet, wherein the metal sheet is disposed at the notch and connected to the connecting portion; The electrode tab is connected to the metal sheet.

2. The electrode sheet according to claim 1, characterized in that, The number of metal sheets is at least two, and the at least two metal sheets are respectively disposed on both sides of the connecting part, with a portion of the at least two metal sheets in contact.

3. The electrode sheet according to claim 2, characterized in that, Also includes: A conductive adhesive is disposed between the metal sheet and the connecting portion to connect the metal sheet and the connecting portion.

4. The electrode sheet according to claim 1, characterized in that, The number of metal sheets is one, and the metal sheet is disposed on one side of the connecting part.

5. The electrode sheet according to claim 4, characterized in that, Also includes: A conductive component is connected to the metal sheet and extends through the connection portion along the thickness direction of the current collector.

6. The electrode sheet according to claim 5, characterized in that, The current collector includes: Matrix; A first metal layer is disposed on one side of the substrate and connected to the metal sheet; A second metal layer is disposed on the other side of the substrate; The conductive component penetrates the first metal layer, the substrate, and the second metal layer, and its two ends are connected to the first metal layer and the second metal layer, respectively.

7. The electrode sheet according to claim 1, characterized in that, The electrode is projected along the thickness direction of the current collector, and the projection of the electrode tab at least partially overlaps with the projection of the notch.

8. The electrode sheet according to any one of claims 1 to 7, characterized in that, The metal sheet covers the notch and fits against one side of the connecting portion.

9. The electrode sheet according to any one of claims 1 to 7, characterized in that, The electrode tab is closer to the middle of the current collector than to the end and middle of the current collector.

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

11. An electronic device, characterized in that, Includes the battery module as described in claim 10.

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