Pole piece assembly, battery and vehicle

Abstract

The utility model discloses a kind of pole piece assembly, battery and vehicle, the pole piece assembly includes positive pole piece and negative pole piece, the positive pole piece includes positive pole current collector, at least one side surface of the positive pole current collector is equipped with positive pole active material layer, the positive pole active material layer is equipped with first convex part and first recess portion in one side of the positive pole current collector away from the positive pole current collector;The negative pole piece includes negative pole current collector, at least one side surface of the negative pole current collector is equipped with negative pole active material layer, the negative pole active material layer is equipped with second convex part and second recess portion in one side of the negative pole current collector away from the negative pole current collector, the first convex part is opposite with the second recess portion and is matched in the second recess portion, the second convex part is opposite with the second recess portion and is matched in the first recess portion. Compared with related art, the pole piece assembly of the utility model embodiment can also take into account the charge-discharge capacity of battery while improving the energy density of battery, so as to realize the double promotion of battery energy density and charge-discharge capacity.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to an electrode assembly, a battery, and a vehicle. Background Technology

[0002] With the rapid development of the new energy vehicle industry, lithium-ion batteries, as their primary power source, directly impact the overall performance of new energy vehicles. To meet market demands for higher energy density, the industry typically increases cell energy density by increasing electrode thickness. However, thicker electrodes lead to a longer lithium-ion transport path within the electrode, increasing resistance to lithium-ion transport and reducing the battery's charge / discharge capacity. Utility Model Content

[0003] This utility model aims to at least partially solve one of the technical problems in the related art.

[0004] Therefore, embodiments of this utility model propose an electrode assembly, a battery, and a vehicle.

[0005] The electrode assembly of this utility model embodiment includes a positive electrode and a negative electrode. The positive electrode includes a positive current collector, and a positive active material layer is provided on at least one side surface of the positive current collector. The positive active material layer has a first protrusion and a first concave portion on the side facing away from the positive current collector. The negative electrode includes a negative current collector, and a negative active material layer is provided on at least one side surface of the negative current collector. The negative active material layer has a second protrusion and a second concave portion on the side facing away from the negative current collector. The first protrusion is opposite to and fits into the second concave portion, and the second protrusion is opposite to and fits into the first concave portion.

[0006] In some embodiments, the outer peripheral contour of the first protrusion is adapted to the inner peripheral contour of the second recess; and / or the outer peripheral contour of the second protrusion is adapted to the inner peripheral contour of the first recess.

[0007] In some embodiments, the cross-section of the first protrusion and / or the second protrusion is rectangular.

[0008] In some embodiments, the first protrusion has a trapezoidal cross-section, and the top width of the first protrusion is smaller than the bottom width of the first protrusion; and / or the second protrusion has a trapezoidal cross-section, and the top width of the second protrusion is smaller than the bottom width of the first protrusion.

[0009] In some embodiments, the height of the first protrusion is greater than or equal to the bottom width of the first protrusion; and / or the height of the second protrusion is greater than or equal to the bottom width of the second protrusion.

[0010] In some embodiments, the height of the first protrusion and / or the second protrusion is 30 μm to 100 μm.

[0011] In some embodiments, the top width of the first protrusion and / or the second protrusion is 10μm to 30μm, and / or the bottom width of the first protrusion and / or the second protrusion is 10μm to 60μm.

[0012] In some embodiments, the top width of the first recess and / or the first recess is 10 μm to 40 μm, and / or the bottom width of the first recess and / or the second recess is 10 μm to 60 μm.

[0013] In some embodiments, the first protrusion and the first recess are arranged at a distance along a first direction, and the first protrusion and the first recess extend along a second direction; The second protrusion and the second recess are arranged at intervals along the first direction, and the second protrusion and the second recess extend along the second direction, the first direction intersecting the second direction.

[0014] In some embodiments, there are multiple first protrusions and multiple second recesses that correspond one-to-one; and / or there are multiple second protrusions and multiple first recesses that correspond one-to-one.

[0015] In some embodiments, a plurality of first protrusions and a plurality of first recesses are arranged alternately along a first direction, and a plurality of second protrusions and a plurality of second recesses are arranged alternately along the first direction.

[0016] The battery of this utility model embodiment includes a separator and the electrode assembly described in any of the above embodiments, wherein the separator is disposed between the positive electrode active material layer and the negative electrode active material layer.

[0017] The vehicle of this utility model embodiment includes the battery described in any of the above embodiments.

[0018] The electrode assembly of this invention features protrusions and recesses between the active material layers of the positive and negative electrodes, respectively, and these protrusions and recesses are coupled along the thickness of the electrode assembly. This reduces the path length of lithium ions in the thickness direction of the positive and negative electrodes, thereby lowering the resistance to lithium ion transport and improving the lithium ion transport efficiency between the electrodes. Simultaneously, the protrusions and recesses increase the effective contact area of ​​the active material layers between the positive and negative electrodes, improving the diffusion efficiency of lithium ions and further enhancing the lithium ion transport efficiency between the electrodes. Therefore, compared with related technologies, the electrode assembly of this invention improves both battery energy density and charge / discharge capability, achieving a dual improvement in both. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the electrode assembly according to an embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the structure of the positive electrode and the negative electrode in an embodiment of this utility model.

[0021] Figure label: 100. Electrode assembly; 1. Positive electrode; 101. Positive current collector; 102. Positive active material layer; 1021. First convex portion; 1022. First concave portion; 2. Negative electrode; 201. Negative current collector; 202. Negative active material layer; 2021. Second convex portion; 2022. Second concave portion; 3. Separator. Detailed Implementation

[0022] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0023] The electrode assembly 100 of this utility model embodiment includes a positive electrode 1 and a negative electrode 2. The positive electrode 1 includes a positive current collector 101, and a positive active material layer 102 is provided on at least one side surface of the positive current collector 101. The positive active material layer 102 is provided with a first protrusion 1021 and a first recess 1022 on the side of the positive current collector 101 facing away from the positive current collector 101.

[0024] The negative electrode 2 includes a negative electrode current collector 201. At least one side surface of the negative electrode current collector 201 is provided with a negative electrode active material layer 202. The side of the negative electrode active material layer 202 facing away from the negative electrode current collector 201 is provided with a second protrusion 2021 and a second recess 2022. The first protrusion 1021 is opposite to and fits into the second recess 2022, and the second protrusion 2021 is opposite to and fits into the second recess 2022.

[0025] During charging, the positive active material layer 102 on the positive electrode 1 ionizes lithium ions and moves towards the negative active material layer 202 on the negative electrode 2. During this movement, a portion of the lithium ions in the positive active material layer 102 flows through the top and side walls of the first protrusion 1021 into the second recess 2022, and then diffuses into the negative active material layer 202 through the top and side walls of the second recess 2022. Another portion of the lithium ions in the positive active material layer 102 flows through the bottom and side walls of the first recess 1022 into the second protrusion 2021, and then diffuses into other parts of the negative active material layer 202 through the top and side walls of the second protrusion 2021.

[0026] Similarly, in this embodiment of the present invention, during discharge, the negative electrode active material layer 202 on the negative electrode 2 ionizes lithium ions and moves towards the positive electrode active material layer 102 on the positive electrode 1. During this movement, a portion of the lithium ions in the negative electrode active material layer 202 flows through the top and side walls of the second protrusion 2021 into the second recess 2022, and then diffuses into the positive electrode active material layer 102 through the bottom and side walls of the second recess 2022. Another portion of the lithium ions in the negative electrode active material layer 202 flows through the bottom and side walls of the second recess 2022 into the first protrusion 1021, and then diffuses into other parts of the positive electrode active material layer 102 through the top and side walls of the first protrusion 1021.

[0027] The electrode assembly 100 of this embodiment of the invention has protrusions and recesses respectively provided between the active material layers of the positive electrode 1 and the negative electrode 2, and the protrusions and recesses are coupled along the thickness of the electrode assembly 100. This reduces the transport path length of lithium ions in the thickness direction of the positive electrode 1 and the negative electrode 2, thereby reducing the resistance to lithium ion transport and improving the lithium ion transport efficiency between the electrodes. At the same time, the provision of protrusions and recesses also increases the effective contact area of ​​the active material layers between the positive electrode 1 and the negative electrode 2, improving the diffusion efficiency of lithium ions and further enhancing the lithium ion transport efficiency between the electrodes. Therefore, compared with related technologies, the electrode assembly 100 of this embodiment of the invention can improve the battery energy density while also taking into account the battery's charge and discharge capacity, thus achieving a dual improvement in battery energy density and charge and discharge capacity.

[0028] In some embodiments, there are multiple protrusions, including the first protrusion 1021 and the second concave portion 2022.

[0029] The interaction of multiple first protrusions 1021 and second concave portions 2022 enhances the mechanical stability between the positive electrode 1 and the negative electrode 2, preventing electrode damage due to volume expansion or contraction during charging and discharging. Multiple protrusions and concave structures provide more channels, making the transport of lithium ions and electrons more efficient, thereby improving the battery's charging and discharging performance. During battery charging and discharging, the electrodes may expand or contract due to chemical reactions. The interaction of multiple protrusions and concave structures helps alleviate this mechanical stress and reduce electrode deformation.

[0030] In some embodiments, the number of second protrusions 2021 and first recesses 1022 are both multiple and correspond one-to-one.

[0031] The interaction of multiple second protrusions 2021 and first concave portions 1022 enhances the mechanical stability between the positive and negative electrodes 2, preventing electrode damage due to volume expansion or contraction during charging and discharging. Multiple protrusions and concave structures provide more channels, making the transport of lithium ions and electrons more efficient, thereby improving the battery's charging and discharging performance. During battery charging and discharging, the electrodes may expand or contract due to chemical reactions. The interaction of multiple protrusions and concave structures helps alleviate this mechanical stress and reduce electrode deformation.

[0032] In some embodiments, a plurality of first protrusions 1021 and a plurality of first recesses 1022 are arranged at intervals along a first direction, and the first protrusions 1021 and first recesses 1022 extend along a second direction. A plurality of second protrusions 2021 and a plurality of second recesses 2022 are arranged at intervals along the first direction, and the second protrusions 2021 and second recesses 2022 extend along the second direction, the first direction being orthogonal to the second direction. For example, as... Figure 1 and Figure 2 As shown, the first direction is the width direction of the electrode plate, and the second direction is the length direction of the electrode plate.

[0033] The spaced arrangement and extension of the first protrusion 1021 and the first recess 1022, as well as the second protrusion 2021 and the second recess 2022, allow for a tighter and more uniform contact between the positive electrode 1 and the negative electrode 2, reducing contact resistance. Furthermore, it helps to enhance the overall structural strength of the electrode assembly 100, preventing damage caused by mechanical stress during battery operation. The heat generated during charging and discharging can be more effectively dissipated, thereby improving the battery's thermal management characteristics.

[0034] In some embodiments, a plurality of first protrusions 1021 and a plurality of first recesses 1022 are arranged alternately along a first direction, and a plurality of second protrusions 2021 and a plurality of second recesses 2022 are arranged alternately along the first direction.

[0035] like Figure 1 and Figure 2As shown, multiple first protrusions 1021 and multiple first recesses 1022 are arranged alternately along a first direction, and multiple second protrusions 2021 and multiple second recesses 2022 are arranged alternately along the first direction, making the lithium-ion transport more uniform across the entire electrode and avoiding local overheating or overload. Due to the uniform distribution of the convex and concave structure, the current distribution across the entire electrode is also more uniform, reducing the risk of local overheating and improving battery safety.

[0036] In some embodiments, the outer peripheral contour of the first protrusion 1021 is adapted to the inner peripheral contour of the second recess 2022.

[0037] like Figure 1 As shown, the outer periphery of the first protrusion 1021 matches the inner periphery of the second concave portion 2022, meaning they are matched in shape and size, ensuring a tight fit during assembly. The matching contours provide a larger contact area, reducing gaps and improving lithium-ion transport efficiency. The increased contact area and tighter contact reduce battery contact resistance, improving overall battery performance. Precise contour matching enhances structural stability between the positive electrode 1 and the negative electrode 2, preventing electrode displacement due to volume changes during charging and discharging. Improved contact efficiency and reduced resistance increase the battery's charge / discharge rate, energy density, and cycle performance. The tight fit between the protrusion and concave portions reduces changes in internal resistance during operation, improving battery reliability.

[0038] In some embodiments, the outer peripheral contour of the second protrusion 2021 is adapted to the inner peripheral contour of the first recess 1022.

[0039] like Figure 1 As shown, the outer periphery of the second protrusion 2021 matches the inner periphery of the first recess 1022, meaning they are matched in shape and size, ensuring a tight fit during assembly. The matching contours provide a larger contact area, reducing gaps and improving lithium-ion transport efficiency. The increased contact area and tighter contact reduce battery contact resistance, improving overall battery performance. Precise contour matching enhances structural stability between the positive electrode 1 and the negative electrode 2, preventing electrode displacement due to volume changes during charging and discharging. Improved contact efficiency and reduced resistance increase the battery's charge / discharge rate, energy density, and cycle performance. The tight fit between the protrusion and recess reduces changes in internal resistance during operation, improving battery reliability.

[0040] Optionally, the cross-section of the first protrusion 1021 and / or the second protrusion 2021 in the first direction is rectangular. That is, only the cross-section of the first protrusion 1021 in the first direction may be rectangular; or the cross-section of the second protrusion 2021 in the first direction may be rectangular; or both the first protrusion 1021 and the second protrusion 2021 may have rectangular cross-sections in the first direction.

[0041] Rectangular cross-sections generally possess greater mechanical strength than circular or other irregular shapes, helping to withstand the mechanical stresses generated during battery charging and discharging. Rectangular cross-sections may offer a larger contact area, which, when combined with corresponding recesses, allows for better lithium-ion transfer, improving battery charging and discharging efficiency. Furthermore, rectangular structures are typically simpler and more cost-effective to manufacture than other complex shapes, contributing to lower battery manufacturing costs.

[0042] In some embodiments, such as Figure 1 and Figure 2 As shown, the first protrusion 1021 has a trapezoidal cross-section in the first direction, and the top width of the first protrusion 1021 is smaller than the bottom width. Because the top of the first protrusion 1021 is narrower, it can be more easily inserted into the corresponding second recess 2021, which improves assembly efficiency. Furthermore, the trapezoidal shape of the protrusion helps guide lithium ions along a specific path, reducing the diffusion distance of lithium ions within the electrode and improving ion transport efficiency.

[0043] In some embodiments, such as Figure 1 and Figure 2 As shown, the second protrusion 2021 has a trapezoidal cross-section in the first direction, and the top width of the second protrusion 2021 is smaller than the bottom width of the first protrusion 1021. Because the top of the second protrusion 2021 is narrower, it can be more easily inserted into the corresponding first recess 1021, which improves assembly efficiency. The trapezoidal shape of the protrusion helps guide lithium ions along a specific path, reducing the diffusion distance of lithium ions within the electrode and improving ion transport efficiency.

[0044] In some embodiments, the height of the first protrusion 1021 is greater than or equal to the bottom width of the first protrusion 1021. This greater-than-equal height provides more paths for lithium-ion transport in the thickness direction of the electrode, helping to reduce the diffusion distance of lithium-ions within the electrode and improve ion transport efficiency.

[0045] In some embodiments, the height of the second protrusion 2021 is greater than or equal to the bottom width of the second protrusion 2021. This greater-than-equal height provides more paths for lithium-ion transport in the thickness direction of the electrode, helping to reduce the diffusion distance of lithium ions within the electrode and improve ion transport efficiency.

[0046] Optionally, the height of the first protrusion 1021 and / or the second protrusion 2021 is 30μm to 100μm. That is, the height of the first protrusion 1021 can be 30μm to 100μm, or the height of the second protrusion 2021 can be 30μm to 100μm, or the height of both the first protrusion 1021 and the second protrusion 2021 can be 30μm to 100μm.

[0047] Optionally, the top width of the first protrusion 1021 and / or the second protrusion 2021 is 10μm to 30μm. That is, the top width of the first protrusion 1021 is 10μm to 30μm, or the top width of the second protrusion 2021 is 10μm to 30μm, or the top width of both the first protrusion 1021 and the second protrusion 2021 is 10μm to 30μm.

[0048] Optionally, the bottom width of the first protrusion 1021 and / or the second protrusion 2021 is 10μm-60μm. That is, the bottom width of the first protrusion 1021 is 10μm-60μm, or the bottom width of the second protrusion 2021 is 10μm-60μm, or the bottom width of both the first protrusion 1021 and the second protrusion 2021 is 10μm-60μm.

[0049] Optionally, the top width of the first recess 1022 and / or the first recess 1022 is 10μm to 40μm. That is, the top width of the first recess 1022 is 10μm to 40μm, or the top width of the first recess 1022 is 10μm to 40μm, or both the first recess 1022 and the top width of the first recess 1022 are 10μm to 40μm.

[0050] Optionally, the bottom width of the first recess 1022 and / or the second recess 2022 is 10μm to 60μm. That is, the bottom width of the first recess 1022 is 10μm to 60μm, or the bottom width of the second recess 2022 is 10μm to 60μm, or the bottom width of both the first recess 1022 and the second recess 2022 is 10μm to 60μm.

[0051] An embodiment of this utility model also discloses a battery, including the electrode assembly 100 and the separator 3 in any of the above embodiments, wherein the separator 3 is disposed between the positive electrode active material layer 102 and the negative electrode active material layer 202.

[0052] The battery of this embodiment features convex and concave portions between the active material layers of the positive electrode 1 and the negative electrode 2, respectively, and these portions are coupled along the thickness of the electrode assembly 100. This reduces the path length of lithium ions in the thickness direction of the positive and negative electrode 1 and 2, thereby lowering the resistance to lithium ion transport and improving the lithium ion transport efficiency between the electrodes. Simultaneously, the convex and concave portions increase the effective contact area of ​​the active material layers between the positive and negative electrode 1 and 2, improving the diffusion efficiency of lithium ions and further enhancing the lithium ion transport efficiency between the electrodes. Therefore, compared with related technologies, the electrode assembly 100 of this embodiment improves both battery energy density and charge / discharge capacity, achieving a dual improvement in both energy density and charge / discharge capacity.

[0053] For example, the battery of this utility model embodiment is manufactured as follows: Example 1: (1) Preparation of positive electrode 1 NCM523, conductive carbon (SP), and PVDF were mixed in a weight ratio of approximately 96:2:2 in the solvent N-methylpyrrolidone and stirred until homogeneous to obtain a positive electrode slurry (positive electrode active material). Aluminum foil was then used as the positive electrode current collector 101. The slurry-coated positive electrode current collector 101 was baked at 120°C for 1 hour, followed by cold pressing, cutting, laser wire bonding, and slitting to prepare the positive electrode sheet 1. Among these, as shown... Figure 2 As shown, the top width A of the first protrusion 1021 is 30 μm, the bottom width B of the first protrusion 1021 is 40 μm, the height C of the first protrusion 1021 is 70 μm, and the bottom width D of the first concave portion 1022 is 35 μm.

[0054] (2) Preparation of negative electrode 2 Graphite, sodium carboxymethyl cellulose, styrene-butadiene rubber, and conductive carbon black were mixed in deionized water at a weight ratio of 96:1.3:1.7:1, stirred evenly, coated, cold-pressed, and then laser-etched with a power of 50%. The cross-sectional morphology of the second concave part was trapezoidal. The mixture was then cut and slit to obtain the negative electrode sheet. Among these steps, such as... Figure 2 As shown, the top width A of the second convex portion 2021 is 30 μm, the bottom width B of the second convex portion 2021 is 40 μm, the height C of the second convex portion 2021 is 70 μm, and the bottom width D of the second concave portion 2022 is 35 μm.

[0055] (3) Assemble bare cells Stack the four layers of positive electrode 1, separator 3, negative electrode 2, and separator 3 in sequence, with separator 3 positioned between positive electrode 1 and negative electrode 2 to provide isolation. Then wind them up and attach finishing tape at the winding point to obtain a bare battery cell. (4) Preparation of electrolyte In an argon atmosphere, ethylene carbonate / ethyl methyl carbonate (3:7) was mixed and then lithium hexafluorophosphate was added, with a lithium hexafluorophosphate concentration of 1.0 mol / L, to obtain the electrolyte. (5) Assemble lithium-ion batteries The bare battery cell is placed into an aluminum shell, dried at 100°C, and then injected with the prepared electrolyte. After vacuum sealing, settling, formation, and shaping, the lithium-ion battery is completed.

[0056] Test method: (1) DCR test (DC internal resistance) a. After letting the battery stand at 25°C for 60 minutes, charge it at a constant current of 1C to 4.3V, and then charge it at a constant voltage of 0.05C. b. After standing at 25℃ for 5 minutes, discharge at a constant current of 1C to 50% SOC; c. After standing at 25℃ for 60 minutes, record the final voltage U1; d. Discharge at a constant current of 4C for 10s at 25℃ and record the ending voltage U2; e. Calculate DCR = (U2 - U1) / 4C.

[0057] (2) Energy density test a. After letting the battery stand at 25°C for 60 minutes, charge it at a constant current of 1 / 3C to 4.3V, and then charge it at a constant voltage to 0.05C. b. After standing at 25℃ for 30 minutes, discharge at a constant current of 1 / 3C to 2.5V; c. Repeat steps ab three times, and take the energy of the last discharge as W0. d. Weigh the battery cell and record its mass as m0; e. Calculate the energy density = W0 / m0.

[0058] Example 2: This is basically the same as Example 1, except that the height C is changed to 90 μm. Example 3: This is basically the same as Example 1, except that the height C is changed to 40 μm. Example 4: It is basically the same as Example 1, except that the width C is changed to 50 μm. Comparative example: The method is basically the same as in Example 1, except that the positive and negative active material layers do not have protrusions or recesses, and the thickness of both the positive and negative active material layers is C=50μm. The experimental data are shown in the table below:

[0059] The comparative examples in the table above are batteries from related technologies, while Examples 1 to 4 are batteries from embodiments of this utility model. Analysis of experimental data shows that the batteries of this utility model improve battery energy density while reducing DC internal resistance, thus enhancing the battery's charge and discharge capabilities.

[0060] Comparative Example 1: The process is basically the same as the previous example, except that in the preparation of the negative electrode 2, silicon oxide, CMC, SBR, conductive carbon black, and carbon nanotubes are mixed in deionized water at a weight ratio of 96:1.2:1.8:0.8:0.2 and stirred evenly to prepare the first active slurry; artificial graphite, CMC, SBR, conductive carbon black, and carbon nanotubes are mixed in deionized water at a weight ratio of 96:1.2:1.8:0.8:0.2 and stirred evenly to prepare the second active slurry. Copper foil is used as the negative electrode current collector 201 for coating (the areal density ratio of the first active layer to the second active layer is 1 / 9), cold-pressed, cut, and slit to prepare the negative electrode 2.

[0061] Comparative Example 2: The process is basically the same as the previous example, except that in the preparation of the negative electrode 2, silicon oxide, CMC, SBR, conductive carbon black, and carbon nanotubes are mixed in deionized water at a weight ratio of 96:1.2:1.8:0.8:2 and stirred evenly to prepare the first active slurry; artificial graphite, CMC, SBR, and conductive carbon black are mixed in deionized water at a weight ratio of 96:1.2:1.8:0.8 and stirred evenly to prepare the second active slurry. Copper foil is used as the negative electrode current collector 201 for coating (the areal density ratio of the first active layer to the second active layer is 1 / 9), cold-pressed, cut, and slit to prepare the negative electrode 2.

[0062] Comparative Example 3: The process is basically the same as the previous example, except that in the preparation of the negative electrode 2, silicon oxide, CMC, SBR, conductive carbon black, and carbon nanotubes are mixed in deionized water at a weight ratio of 96:1.2:1.8:0.98:0.2 and stirred evenly to prepare the first active slurry; artificial graphite, CMC, SBR, and conductive carbon black are mixed in deionized water at a weight ratio of 96:1.2:1.8:0.98 and stirred evenly to prepare the second active slurry. Copper foil is used as the negative electrode current collector 201 for coating (the areal density ratio of the first active layer to the second active layer is 1 / 9), cold-pressed, cut, and slit to prepare the negative electrode 2.

[0063] The experimental data are shown in the table below:

[0064] The examples in the table above are batteries from related technologies, while Comparative Examples 1 to 3 are batteries from embodiments of this utility model. Analysis of experimental data shows that the batteries of this utility model reduce DC internal resistance while increasing the number of charge-discharge cycles, thereby improving both battery energy density and DC internal resistance, and ultimately enhancing the battery's charge-discharge capability.

[0065] An embodiment of this utility model also discloses a vehicle that includes the battery in any of the above embodiments, thereby improving the vehicle's performance.

[0066] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "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 are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to 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 utility model.

[0067] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0068] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0069] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0070] In this utility model, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0071] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An electrode assembly, characterized in that, include: A positive electrode sheet, the positive electrode sheet including a positive current collector, at least one side surface of the positive current collector is provided with a positive active material layer, and the side of the positive active material layer opposite to the positive current collector is provided with a first protrusion and a first concave portion; A negative electrode sheet, the negative electrode sheet including a negative electrode current collector, at least one side surface of the negative electrode current collector is provided with a negative electrode active material layer, the side of the negative electrode active material layer opposite to the negative electrode current collector is provided with a second protrusion and a second concave portion, the first protrusion and the second concave portion are opposite to and cooperate within the second concave portion, and the second protrusion and the second concave portion are opposite to and cooperate within the first concave portion.

2. The electrode assembly according to claim 1, characterized in that, The outer peripheral contour of the first protrusion is adapted to the inner peripheral contour of the second concave portion; and / or the outer peripheral contour of the second protrusion is adapted to the inner peripheral contour of the first concave portion.

3. The electrode assembly according to claim 1 or 2, characterized in that, The cross-section of the first protrusion and / or the second protrusion is rectangular.

4. The electrode assembly according to claim 1 or 2, characterized in that, The first protrusion has a trapezoidal cross-section, and the top width of the first protrusion is smaller than the bottom width of the first protrusion; and / or the second protrusion has a trapezoidal cross-section, and the top width of the second protrusion is smaller than the bottom width of the first protrusion.

5. The electrode assembly according to claim 4, characterized in that, The height of the first protrusion is greater than or equal to the bottom width of the first protrusion; and / or the height of the second protrusion is greater than or equal to the bottom width of the second protrusion.

6. The electrode assembly according to claim 4, characterized in that, The height of the first protrusion and / or the second protrusion is 30μm to 100μm.

7. The electrode assembly according to claim 4, characterized in that, The top width of the first protrusion and / or the second protrusion is 10μm to 30μm, and / or the bottom width of the first protrusion and / or the second protrusion is 10μm to 60μm.

8. The electrode assembly according to claim 4, characterized in that, The width of the first recess and / or the top of the first recess is 10μm to 40μm, and / or the width of the bottom of the first recess and / or the second recess is 10μm to 60μm.

9. The electrode assembly according to any one of claims 1-8, characterized in that, The first protrusion and the first recess are arranged at intervals along a first direction, and the first protrusion and the first recess extend along a second direction; The second protrusion and the second recess are arranged at intervals along the first direction, and the second protrusion and the second recess extend along the second direction, the first direction intersecting the second direction.

10. The electrode assembly according to any one of claims 1-8, characterized in that, The first convex portion and the second concave portion are both multiple and correspond one-to-one; and / or the second convex portion and the first concave portion are both multiple and correspond one-to-one.

11. The electrode assembly according to claim 10, characterized in that, A plurality of first protrusions and a plurality of first recesses are arranged alternately along a first direction, and a plurality of second protrusions and a plurality of second recesses are arranged alternately along the first direction.

12. A battery, characterized in that, The invention includes a separator and an electrode assembly as described in any one of claims 1-11, wherein the separator is disposed between the positive electrode active material layer and the negative electrode active material layer.

13. A vehicle, characterized in that, Includes the battery described in claim 12.

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