Battery cell

Abstract

Disclosed in the embodiments of the present application is a battery cell. The battery cell comprises a housing and an electrode assembly. The electrode assembly comprises an electrode sheet. The electrode sheet comprises a current collector and an active layer. The active layer comprises an edge portion and a body portion, wherein the edge portion is arranged on at least one side of the body portion in a third direction; the surface of the side of the edge portion away from the current collector is provided with a plurality of first recesses that are spaced apart from each other in the third direction and in a first direction; and the surface of the side of the body portion away from the current collector is provided with a plurality of second grooves that are spaced apart from each other in the third direction and extend in the first direction.

Description

Single cell battery

[0001] This application claims priority to Chinese Patent Application No. 202510374512.2, filed on March 27, 2025, entitled "Single Cell Battery", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of battery technology, and in particular to a single-cell battery. Background Technology

[0003] Lithium-ion battery packs are a primary energy storage solution for consumer electronics and electric vehicles. Rapid advancements in materials science and engineering have significantly improved the performance, reliability, and safety of lithium-ion batteries while reducing costs. At the electrode level, the energy density of individual cells in a lithium-ion battery pack can be increased by increasing the coating thickness of the active layer on the electrode. However, increasing the electrode thickness leads to problems such as lower actual capacity utilization, poorer rate performance, and longer electrolyte wetting time.

[0004] To ensure that thick electrodes can achieve sufficiently high capacity utilization and maintain superior rate performance to improve the performance of lithium-ion battery packs, and to shorten electrolyte wetting time and reduce manufacturing costs, large-size single cells in energy storage products using stacking technology typically employ electrode perforation structures. This significantly improves wetting performance, storage performance, and reduces high and low temperature DC resistance (DCR). Furthermore, from a cost perspective, increasing the thickness of a single layer of material can reduce bill of materials (BOM) costs. However, during electrode perforation, material at the cut edges of the electrode is prone to detachment, easily leading to edge decarburization, severe edge foil leakage, and localized lithium plating. This results in low electrode yield, poor single-cell performance, high risk of environmental dust particles, and high high-voltage insulation risks. Summary of the Invention

[0005] Embodiments of this application provide a single-cell battery that at least partially solves the aforementioned problems and / or other potential problems of current electrode perforation structures.

[0006] The single-cell battery provided in this application embodiment has intersecting first, second, and third directions. The single-cell battery includes: a housing; and an electrode assembly disposed within the housing. The electrode assembly includes an electrode sheet. The electrode sheet includes a current collector and an active layer. The current collector includes a tab and a coating portion, the tab being disposed on at least one side of the coating portion in the first direction. The active layer is disposed on at least one side of the coating portion in the second direction. The active layer includes an edge portion and a main body portion, the edge portion being disposed on at least one side of the main body portion in the third direction. A plurality of first grooves are provided on the surface of the edge portion away from the current collector, the plurality of first grooves being spaced apart along the third direction and the first direction. A plurality of second grooves are provided on the surface of the main body portion away from the current collector, the plurality of second grooves being spaced apart along the third direction, and the second grooves extending along the first direction.

[0007] In some embodiments, a first thinning region is formed on the edge portion, the first thinning region being located on at least one side of the edge portion in a first direction, and a first groove being located outside the first thinning region. A second thinning region is formed on the body portion, the second thinning region being located on at least one side of the body portion in the first direction, and a second groove being located outside the second thinning region.

[0008] In some embodiments, both the first thinning region and the second thinning region are adjacent to the tab portion.

[0009] In some embodiments, the edge portions are disposed on both sides of the main body portion in a third-direction orientation.

[0010] In some embodiments, an active layer is provided on both sides of the current collector in the second direction, and a first groove is provided on each of the active layers on both sides of the current collector in the second direction. The first groove on the active layer on one side of the current collector in the second direction is offset from the first groove on the active layer on the other side of the current collector in the second direction.

[0011] In some embodiments, the orthographic projection shape of the opening of the first groove on the coating portion is circular, and the diameter of the opening of the first groove is W1 mm. In a first direction, the center distance between the openings of two adjacent first grooves is L1 mm. In a third direction, the center distance between the openings of two adjacent first grooves is L2 mm. L1 and W1 satisfy: 1.3 ≤ L1 / W1 ≤ 50, and / or, L2 and W1 satisfy: 1.3 ≤ L2 / W1 ≤ 50.

[0012] In some embodiments, W1 satisfies: 0.04≤W1≤0.15.

[0013] In some embodiments, L1 satisfies: 0.2≤L1≤2, and / or L2 satisfies: 0.2≤L2≤2.

[0014] In some embodiments, on a plane parallel to the first direction and the third direction, the minimum distance between the center of the groove opening of the first groove and the tab in the first direction is P1 mm, where P1 satisfies: 1≤P1≤5.

[0015] In some embodiments, the orthographic projection shape of the opening of the second groove on the coating portion is rectangular. In the third direction, the width of the opening of the second groove is W2 mm, and the distance between the central axes of two adjacent openings of the second groove is L3 mm. W2 and L3 satisfy: 1.3≤L3 / W2≤50.

[0016] In some embodiments, on a plane parallel to the first direction and the third direction, the minimum distance between the opening of the second groove and the tab in the first direction is P2 mm, where P2 satisfies: 1≤P2≤5.

[0017] In some embodiments, W2 satisfies: 0.04≤W2≤0.15, and / or, L3 mm satisfies: 0.2≤L3≤2.

[0018] In some embodiments, the thickness of the active layer in the second direction is H1 mm. The depth of the first trench in the second direction is H2 mm. The depth of the second trench in the second direction is H3 mm. H2 and H1 satisfy: 0.05 ≤ H2 / H1 ≤ 0.5, and / or, H3 and H1 satisfy: 0.05 ≤ H3 / H1 ≤ 0.5.

[0019] In some embodiments, on a plane parallel to the first and third directions, the sum of the areas of the openings of the second grooves on the active layer located on one side of the current collector in the second direction is S1 mm. 2 And the area of ​​the coated part is S2 mm 2 S1 and S2 satisfy: 0.04≤S1 / S2≤0.15.

[0020] In some embodiments, in the third direction, the width of the edge portion located on any side of the main body portion is T1 mm, and T1 and L3 satisfy: T1 / L3≤2.

[0021] In the single-cell battery provided in this application embodiment, the active layer includes a main body and an edge portion. The edge portion is disposed on the side of the main body facing the third direction. The surface of the edge portion away from the current collector has multiple first grooves, and the surface of the main body away from the current collector has multiple second grooves. By providing first grooves on the edge portion, the stress exerted on the main body by the cutter can be released, reducing the stress impact of the cutter on the electrode. This greatly reduces the problem of material easily falling off at the cutting edge of the electrode when the cutter forms the second groove on the main body, thereby avoiding problems such as edge decarburization, severe edge foil leakage, and localized lithium plating caused by material falling off at the cutting edge. Attached Figure Description

[0022] The technical solution and other beneficial effects of this application will become apparent from the following detailed description of specific embodiments in conjunction with the accompanying drawings.

[0023] Figure 1 shows a schematic diagram of the structure of a single battery cell according to some embodiments of this application;

[0024] Figure 2 shows a schematic planar view of the electrode of a single cell according to some embodiments of this application;

[0025] Figure 3 is a cross-sectional view AA of Figure 2;

[0026] Figure 4 shows another schematic planar view of an electrode of a single cell provided according to some embodiments of this application;

[0027] Figure 5 is a cross-sectional view of BB in Figure 2.

[0028] Explanation of reference numerals in the attached drawings: 100, single cell; 101, casing; 102, electrode assembly; 1, electrode sheet; 110, positive electrode sheet; 120, negative electrode sheet; 130, separator; 11, current collector; 111, tab; 112, coating; 12, active layer; 121, edge; 122, main body; 1211, first groove; 1212, first thinning area; 1221, second groove; 1222, second thinning area. Detailed Implementation

[0029] The preferred embodiments of this application are described in detail below with reference to the accompanying drawings to fully introduce the technical content of this application to those skilled in the art, to demonstrate that this application can be implemented, and to make the disclosed technical content of this application clearer, so that those skilled in the art can more easily understand how to implement this application. However, this application can be embodied in many different forms of embodiments, and the protection scope of this application is not limited to the embodiments mentioned herein. The description of the embodiments below is not intended to limit the scope of this application.

[0030] The directional terms used in this application, such as "up", "down", "front", "back", "left", "right", "inner", "outer", and "side", are only for the directions shown in the accompanying drawings. The directional terms used herein are for the purpose of explaining and illustrating this application, and not for limiting the scope of protection of this application.

[0031] In the accompanying drawings, components with the same structure are indicated by the same numerical designation, and components with similar structures or functions are indicated by similar numerical designations. Furthermore, for ease of understanding and description, the dimensions and thicknesses of each component shown in the drawings are arbitrary, and this application does not limit the dimensions and thicknesses of each component.

[0032] Referring to Figures 1 and 2, this embodiment provides a single-cell battery 100. The single-cell battery 100 has intersecting first direction M, second direction N, and third direction P. The single-cell battery 100 includes a housing 101 and an electrode assembly 102. The electrode assembly 102 is disposed within the housing 101. The electrode assembly 102 includes electrode plates 1. Specifically, the electrode assembly 102 includes positive electrode plates 110 and negative electrode plates 120 arranged alternately along the second direction N. A separator 130 is provided between any adjacent positive electrode plates 110 and negative electrode plates 120.

[0033] Please refer to Figures 2-4. The electrode 1 includes a current collector 11 and an active layer 12.

[0034] Referring to Figure 3, the current collector 11 includes an electrode portion 111 and a coating portion 112, with the electrode portion 111 disposed on at least one side of the coating portion 112 in the first direction M. In this embodiment, the electrode portion 111 is disposed on one side (right side) of the coating portion 112 in the first direction M.

[0035] Referring to Figure 3, the active layer 12 is disposed on at least one side of the coating portion 112 in the second direction N. In this embodiment, the active layer 12 is disposed on both sides (upper and lower sides) of the coating portion 112 in the second direction N.

[0036] Referring to Figure 2, the active layer 12 includes an edge portion 121 and a main body portion 122. The edge portion 121 is disposed on at least one side of the main body portion 122 in the third direction P. In this embodiment, the edge portion 121 is disposed on both sides of the main body portion 122 in the third direction P.

[0037] Referring to Figures 2 and 3, the surface of the edge portion 121 away from the current collector 11 is provided with a plurality of first grooves 1211, which are spaced apart along a third direction P and a first direction M. The surface of the main body portion 122 away from the current collector 11 is provided with a plurality of second grooves 1221, which are spaced apart along a third direction P and extend along the first direction M. By providing the first grooves 1211 on the edge portion 121, the stress exerted by the cutter on the main body portion 122 can be released, reducing the stress influence of the cutter on the electrode 1. This greatly reduces the problem of material easily falling off at the cutting edge of the electrode 1 when the cutter forms the second grooves 1221 on the main body portion 122, thereby avoiding problems such as edge decarburization, severe edge foil leakage, and local lithium plating caused by material falling off at the cutting edge.

[0038] Referring to Figure 2, a first thinning region 1212 is formed on the edge portion 121, and a first groove 1211 is located outside the first thinning region 1212. The first thinning region 1212 is located on at least one side of the edge portion 121 in the first direction M. In this embodiment, the first thinning region 1212 is located on one side (right side) of the edge portion 121 in the first direction M. Since the first thinning region 1212 is relatively thin, if a first groove 1211 is formed in the first thinning region 1212, it is easy to cause process problems such as foil leakage. In addition, the first thinning region 1212 has less active material, and if a first groove 1211 is formed in the first thinning region 1212, lithium plating problems are easy to occur. Therefore, it is possible to avoid forming a first groove 1211 in the first thinning region 1212.

[0039] Referring to Figure 2, the main body 122 has a second thinning region 1222, and a second groove 1221 is located outside the second thinning region 1222. The second thinning region 1222 is located on at least one side of the main body 122 in the first direction M. In this embodiment, the second thinning region 1222 is located on one side (right side) of the main body 122 in the first direction M. Since the second thinning region 1222 is relatively thin, if a second groove 1221 is formed in the second thinning region 1222, it is easy to cause process problems such as foil leakage. In addition, the second thinning region 1222 has less active material, and if a second groove 1221 is formed in the second thinning region 1222, lithium plating problems are easy to occur. Therefore, it is possible to avoid forming a second groove 1221 in the second thinning region 1222.

[0040] Referring to Figure 3, the current collector 11 has active layers 12 on both sides in the second direction N, and each active layer 12 on both sides of the current collector 11 in the second direction N has a first groove 1211. In some embodiments, the first groove 1211 on one side of the active layer 12 in the second direction N is offset from the first groove 1211 on the other side of the active layer 12 in the second direction N. That is, the first groove 1211 on the upper side of the active layer 12 in the second direction N is offset from the first groove 1211 on the lower side of the active layer 12 in the second direction N; in other words, the upper first groove 1211 and the lower first groove 1211 are not aligned with each other in the second direction N. This can increase the toughness of the electrode 1 and reduce the risk of tape breakage in processes such as coil manufacturing.

[0041] Please refer to Figure 4. The orthographic projection shape of the opening of the first groove 1211 on the coating part 112 is circular. The diameter of the opening of the first groove 1211 is W1 mm, where W1 satisfies: 0.04 ≤ W1 ≤ 0.15. That is, the diameter W1 mm ​​of the opening of the first groove 1211 is controlled within the range of 0.04 mm to 0.15 mm. For example, W1 can be one of 0.04, 0.06, 0.08, 0.1, 0.12, or 0.15, or within any combination of two of these values. The specific values ​​of W1 given above are merely illustrative examples, and any value within the range of 0.04 to 0.15 is within the protection scope of this application.

[0042] Please refer to Figure 4. In the first direction M, the center distance between the openings of two adjacent first slots 1211 is L1 mm, where L1 satisfies: 0.2 ≤ L1 ≤ 2. That is, the center distance L1 mm between the openings of two adjacent first slots 1211 is controlled within the range of 0.2 mm to 2 mm. For example, L1 can be one of 0.2, 0.5, 0.8, 1, 1.2, 1.5, 1.8, or 2, or fall within any combination of these values. The specific values ​​of L1 given above are merely illustrative; any value within the range of 0.2 to 2 is within the scope of protection of this application.

[0043] Please refer to Figure 4. On the third direction P, the center distance between the openings of two adjacent first slots 1211 is L2 mm, where L2 satisfies: 0.2 ≤ L2 ≤ 2. That is, the center distance L2 mm between the openings of two adjacent first slots 1211 is controlled within the range of 0.2 mm to 2 mm. For example, L2 can be one of 0.2, 0.5, 0.8, 1, 1.2, 1.5, 1.8, or 2, or within any combination of two of these values. The specific values ​​of L2 given above are merely illustrative examples, and any value within the range of 0.2 to 2 is within the protection scope of this application.

[0044] Please refer to Figure 4. The diameter W1 mm ​​of the opening of the first groove 1211, the center distance L1 mm between the openings of two adjacent first grooves 1211, and the center distance L2 mm between the openings of two adjacent first grooves 1211 satisfy: 1.3≤L1 / W1≤50, and / or, 1.3≤L2 / W1≤50.

[0045] Specifically, in some embodiments, the ratio of the center distance L1 mm between the openings of two adjacent first slots 1211 to the diameter W1 mm ​​of the opening of the first slot 1211 is controlled within the range of 1.3 to 50. For example, the ratio of the center distance L1 mm between the openings of two adjacent first slots 1211 to the diameter W1 mm ​​of the opening of the first slot 1211 can be one of 1.3, 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50, or within any combination of two of these values. The specific values ​​of this ratio are given above as examples only, and any value within the range of 1.3 to 50 is within the protection scope of this application.

[0046] Specifically, in some embodiments, the ratio of the center distance L2 mm between the openings of two adjacent first slots 1211 to the diameter W1 mm ​​of the opening of the first slot 1211 is controlled within the range of 1.3 to 50. For example, the ratio of the center distance L2 mm between the openings of two adjacent first slots 1211 to the diameter W1 mm ​​of the opening of the first slot 1211 can be one of 1.3, 5, 10, 15, 20, 25, 30, 35, 40, 45, or 50, or within any combination of two of these values. The specific values ​​of this ratio are given above as examples only, and any value within the range of 1.3 to 50 is within the protection scope of this application.

[0047] Table 1. Parameters and test results for Examples 1-16

[0048] As shown in Table 1, in Examples 1 to 12, L1 / W1 does not exceed the parameter range of this application. Its electrode cutting edge powder shedding rate is 0-0.4%, the wetting performance improvement rate is 12%-18%, and the edge lithium plating probability is 0. Therefore, L1 / W1 does not exceed the parameter range of this application and can balance the three performance parameters: electrode cutting edge powder shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0049] As shown in Table 1, in Example 13, L1 / W1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 13 is 0.4%, which falls within the range of electrode edge shedding rates for Examples 1 to 6. The wetting performance improvement rate of Example 13 is 13%, which falls within the range of electrode wetting performance improvement rates for Examples 1 to 6. The edge lithium plating probability of Example 13 is 2.2%, which is higher than the range of edge lithium plating probabilities for Examples 1 to 6, meaning that the edge lithium plating probability of Example 13 is significantly higher than that of Examples 1 to 6. Therefore, it is evident that the L1 / W1 of Example 13 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0050] As shown in Table 1, in Example 14, L1 / W1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 14 is 1%, which is higher than the range of electrode edge shedding rates in Examples 1 to 6, meaning the electrode edge shedding rate of Example 14 is significantly higher than that in Examples 1 to 6. The wetting performance improvement rate of Example 14 is 6%, which is lower than the range of wetting performance improvement rates in Examples 1 to 6, meaning it is significantly lower than that in Examples 1 to 6. The edge lithium plating probability of Example 14 is 0, which is within the range of edge lithium plating probabilities in Examples 1 to 6. Therefore, it is evident that the L1 / W1 of Example 14 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0051] As shown in Table 1, in Examples 1 to 12, L2 / W1 did not exceed the parameter range of this application. Its electrode cutting edge powder shedding rate was 0-0.4%, the wetting performance improvement rate was 12%-18%, and the edge lithium plating probability was 0. Therefore, L2 / W1 did not exceed the parameter range of this application and could balance the three performance parameters of electrode cutting edge powder shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0052] As shown in Table 1, in Example 15, L2 / W1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 15 is 0.4%, which falls within the range of electrode edge shedding rates for Examples 7 to 12. The wetting performance improvement rate of Example 15 is 13%, which falls within the range of electrode wetting performance improvement rates for Examples 7 to 12. The edge lithium plating probability of Example 15 is 2%, which is higher than the range of edge lithium plating probabilities for Examples 7 to 12; that is, the edge lithium plating probability of Example 15 is significantly higher than that of Examples 7 to 12. Therefore, it is evident that the L2 / W1 of Example 15 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0053] As shown in Table 1, in Example 16, L2 / W1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 16 is 1%, which is higher than the range of electrode edge shedding rates in Examples 7 to 12, meaning the electrode edge shedding rate of Example 16 is significantly higher than that of Examples 7 to 12. The wetting performance improvement rate of Example 16 is 6%, which is lower than the range of wetting performance improvement rates in Examples 7 to 12, meaning the wetting performance improvement rate of Example 16 is significantly lower than that of Examples 7 to 12. The edge lithium plating probability of Example 16 is 0, which is within the range of edge lithium plating probabilities in Examples 7 to 12. Therefore, it is evident that the L2 / W1 of Example 16 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0054] Please refer to Figure 4. On a plane parallel to the first direction M and the third direction P, the minimum distance between the center of the groove opening of the first groove 1211 and the tab 111 in the first direction M is P1 mm, where P1 satisfies: 1 ≤ P1 ≤ 5. That is, the minimum distance P1 mm between the center of the groove opening of the first groove 1211 and the tab 111 in the first direction M is controlled within the range of 1 mm to 5 mm. For example, P1 can be one of 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5, or within any combination of two of them. The specific values ​​of P1 given above are merely illustrative, and any value within the range of 1 to 5 is within the protection scope of this application.

[0055] Table 2 Parameters and Test Results for Examples 17-23

[0056] As shown in Table 2, in Examples 17 to 21, P1 did not exceed the parameter range of this application. Its electrode cutting edge powder shedding rate was 0-0.1%, wetting performance improvement rate was 12.8%-12.9%, and edge lithium plating probability was 0. Therefore, P1 did not exceed the parameter range of this application, and it can balance the three performance parameters of electrode cutting edge powder shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0057] As shown in Table 2, in Example 22, P1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 22 is 0.1%, which falls within the range of electrode edge shedding rates in Examples 17 to 21. The wetting performance improvement rate of Example 22 is 6.4%, lower than the range of wetting performance improvement rates in Examples 17 to 21, meaning the wetting performance improvement rate of Example 22 is significantly lower than that of Examples 17 to 21. The edge lithium plating probability of Example 22 is 5%, higher than the range of edge lithium plating probabilities in Examples 17 to 21, meaning the edge lithium plating probability of Example 22 is significantly higher than that of Examples 17 to 21. Therefore, it is evident that P1 in Example 22 exceeds the parameter range of this application, failing to simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0058] As shown in Table 2, in Example 23, P1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 23 is 0.3%, which is higher than the range of electrode edge shedding rates in Examples 17 to 21, meaning the electrode edge shedding rate of Example 23 is higher than that in Examples 17 to 21. The wetting performance improvement rate of Example 23 is 6.4%, which is lower than the range of wetting performance improvement rates in Examples 17 to 21, meaning the wetting performance improvement rate of Example 23 is significantly lower than that in Examples 17 to 21. The edge lithium plating probability of Example 23 is 0, which is within the range of edge lithium plating probabilities in Examples 17 to 21. Therefore, it is evident that P1 in Example 23 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0059] Please refer to Figure 4. The orthographic projection shape of the opening of the second groove 1221 on the coating part 112 is rectangular. In the third direction P, the width of the opening of the second groove 1221 is W2 mm, where W2 satisfies: 0.04 ≤ W2 ≤ 0.15. That is, the width W2 mm of the opening of the second groove 1221 is controlled within the range of 0.04 mm to 0.15 mm. For example, W2 can be one of 0.04, 0.06, 0.08, 0.1, 0.12, or 0.15, or within any combination of two of these values. The specific values ​​of W2 given above are merely illustrative examples, and any value within the range of 0.04 to 0.15 is within the protection scope of this application.

[0060] Please refer to Figure 4. The distance between the central axes of the openings of two adjacent second slots 1221 is L3 mm, where L3 satisfies: 0.2 ≤ L3 ≤ 2. That is, the distance L3 mm between the central axes of the openings of two adjacent second slots 1221 is controlled within the range of 0.2 mm to 2 mm. For example, L3 can be one of 0.2, 0.5, 0.8, 1, 1.2, 1.5, 1.8, or 2, or within any combination of these values. The specific values ​​of L3 given above are merely illustrative; any value within the range of 0.2 to 2 is within the scope of protection of this application.

[0061] Please refer to Figure 4. The width W2 mm of the opening of the second groove 1221 and the distance L3 mm between the central axes of two adjacent openings of the second groove 1221 satisfy the following condition: 1.3 ≤ L3 / W2 ≤ 50. That is, the ratio of the distance L3 mm between the central axes of two adjacent openings of the second groove 1221 to the width W2 mm of the opening of the second groove 1221 is controlled within the range of 1.3 to 50. For example, the ratio of the distance L3 mm between the central axes of two adjacent openings of the second groove 1221 to the width W2 mm of the opening of the second groove 1221 can be one of 1.3, 5, 10, 15, 20, 25, 30, 35, 40, 45 or 50 or within any combination of two of them. The specific values ​​of the above ratio are only given as examples, and any value within the range of 1.3 to 50 is within the protection scope of this application.

[0062] Table 3 Parameters and test results for Examples 24-31

[0063] As shown in Table 3, in Examples 24 to 29, L3 / W2 did not exceed the parameter range of this application. Its electrode cutting edge powder shedding rate was 0, the wetting performance improvement rate was 5.2%-40%, and the edge lithium plating probability was 0-0.4%. Therefore, L3 / W2 did not exceed the parameter range of this application and could balance the three performance parameters of electrode cutting edge powder shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0064] As shown in Table 3, in Example 30, L3 / W2 exceeds the parameter range of this application. The electrode edge shedding rate of Example 30 is 3%, which is higher than the range of electrode edge shedding rates in Examples 24 to 29, meaning the electrode edge shedding rate of Example 30 is significantly higher than that of Examples 24 to 29. The wetting performance improvement rate of Example 30 is 11.4%, which is within the range of electrode edge shedding rates in Examples 24 to 29. The edge lithium plating probability of Example 30 is 15%, which is higher than the range of edge lithium plating probabilities in Examples 24 to 29, meaning the edge lithium plating probability of Example 30 is significantly higher than that of Examples 24 to 29. Therefore, it is evident that the L3 / W2 of Example 30 exceeds the parameter range of this application, and it is impossible to simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0065] As shown in Table 3, in Example 31, L3 / W2 exceeds the parameter range of this application. The electrode edge shedding rate of Example 31 is 0.5%, which is higher than the range of electrode edge shedding rates in Examples 24 to 29, meaning the electrode edge shedding rate of Example 31 is higher than that of Examples 24 to 29. The wetting performance improvement rate of Example 31 is 1%, which is lower than the range of wetting performance improvement rates in Examples 24 to 29, meaning the wetting performance improvement rate of Example 31 is significantly lower than that of Examples 24 to 29. The edge lithium plating probability of Example 31 is 0, which is within the range of edge lithium plating probabilities in Examples 24 to 29. Therefore, it is evident that the L3 / W2 of Example 31 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0066] Referring to Figure 4, on a plane parallel to the first direction M and the third direction P, the minimum distance between the opening of the second groove 1221 and the tab 111 in the first direction M is P2 mm, where P2 satisfies: 1 ≤ P2 ≤ 5. That is, the minimum distance P2 mm between the opening of the second groove 1221 and the tab 111 in the first direction M is controlled within the range of 1 mm to 5 mm. For example, P2 can be one of 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5, or within any combination of two of these values. The specific values ​​of P2 given above are merely illustrative; any value within the range of 1 to 5 is within the scope of protection of this application.

[0067] Table 4 Parameters and test results for Examples 32-38

[0068] As shown in Table 4, in Examples 32 to 36, P2 did not exceed the parameter range of this application. Its electrode cutting edge powder shedding rate was 0-0.1%, the wetting performance improvement rate was 12.4%-13%, and the edge lithium plating probability was 0-0.2%. Therefore, P2 did not exceed the parameter range of this application and could balance the three performance parameters: electrode cutting edge powder shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0069] As shown in Table 4, in Example 37, P2 exceeds the parameter range of this application. The electrode edge shedding rate of Example 37 is 0, falling within the range of electrode edge shedding rates of Examples 32 to 36. The wetting performance improvement rate of Example 37 is 6.5%, lower than the range of wetting performance improvement rates of Examples 32 to 36, meaning the wetting performance improvement rate of Example 37 is significantly lower than that of Examples 32 to 36. The edge lithium plating probability of Example 37 is 5%, higher than the range of edge lithium plating probabilities of Examples 32 to 36, meaning the edge lithium plating probability of Example 37 is significantly higher than that of Examples 32 to 36. Therefore, it is evident that P2 in Example 37 exceeds the parameter range of this application, failing to simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0070] As shown in Table 4, in Example 38, P2 exceeds the parameter range of this application. The electrode edge shedding rate of Example 38 is 0.7%, which is higher than the range of electrode edge shedding rates for Examples 32 to 36, meaning the electrode edge shedding rate of Example 38 is significantly higher than that of Examples 32 to 36. The wetting performance improvement rate of Example 38 is 6.2%, which is lower than the range of wetting performance improvement rates for Examples 32 to 36, meaning the wetting performance improvement rate of Example 38 is significantly lower than that of Examples 32 to 36. The edge lithium plating probability of Example 38 is 0, which is within the range of edge lithium plating probabilities for Examples 32 to 36. Therefore, it is evident that P2 in Example 38 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0071] Please refer to Figures 3 and 5. The thickness of the active layer 12 in the second direction N is H1 mm. The depth of the first groove 1211 in the second direction N is H2 mm. The depth of the second groove 1221 in the second direction N is H3 mm. H1 and H2 satisfy 0.05 ≤ H2 / H1 ≤ 0.5, and / or, H1 and H3 satisfy 0.05 ≤ H3 / H1 ≤ 0.5.

[0072] Specifically, the ratio of the depth H2 mm of the first groove 1211 in the second direction N to the thickness H1 mm of the active layer 12 in the second direction N is controlled within the range of 0.05 to 0.5. For example, the ratio of the depth H2 mm of the first groove 1211 in the second direction N to the thickness H1 mm of the active layer 12 in the second direction N can be one of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5, or within any combination of these values. The specific values ​​of this ratio are given above as examples only, and any value within the range of 0.05 to 0.5 is within the protection scope of this application.

[0073] Specifically, the ratio of the depth H3 mm of the second groove 1221 in the second direction N to the thickness H1 mm of the active layer 12 in the second direction N is controlled within the range of 0.05 to 0.5. For example, the ratio of the depth H3 mm of the second groove 1221 in the second direction N to the thickness H1 mm of the active layer 12 in the second direction N can be one of 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5, or within any combination of these values. The specific values ​​of this ratio are given above as examples only, and any value within the range of 0.05 to 0.5 is within the protection scope of this application.

[0074] Table 5 shows the parameters and test results for Examples 39-54.

[0075] As shown in Table 5, in Examples 39 to 50, H2 / H1 did not exceed the parameter range of this application. The electrode cutting edge powder shedding rate was 0, the wetting performance improvement rate was 10.3%-21%, and the edge lithium plating probability was 0-0.2%. Therefore, H2 / H1 did not exceed the parameter range of this application, and it can balance the three performance parameters: electrode cutting edge powder shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0076] As shown in Table 5, in Example 51, H2 / H1 exceeds the parameter range of this application. The electrode cutting edge dust loss rate of Example 51 is 1%, which is higher than the range of electrode cutting edge dust loss rates in Examples 45 to 50, meaning the electrode cutting edge dust loss rate of Example 51 is higher than that of Examples 45 to 50. The wetting performance improvement rate of Example 51 is 6.2%, which is lower than the range of wetting performance improvement rates in Examples 45 to 50, meaning the wetting performance improvement rate of Example 51 is significantly lower than that of Examples 45 to 50. The edge lithium plating probability of Example 51 is 4%, which is higher than the range of edge lithium plating probabilities in Examples 45 to 50, meaning the edge lithium plating probability of Example 51 is significantly higher than that of Examples 45 to 50. Therefore, it can be seen that H2 / H1 in Example 51 exceeds the parameter range of this application and cannot take into account the three performance parameters of electrode cutting edge powder loss rate, wetting performance improvement rate and edge lithium plating probability.

[0077] As shown in Table 5, in Example 52, H2 / H1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 52 is 2%, which is higher than the range of electrode edge shedding rates in Examples 45 to 50, meaning the electrode edge shedding rate of Example 52 is higher than that of Examples 45 to 50. The wetting performance improvement rate of Example 52 is 6.7%, which is lower than the range of wetting performance improvement rates in Examples 45 to 50, meaning the wetting performance improvement rate of Example 52 is significantly lower than that of Examples 45 to 50. The edge lithium plating probability of Example 52 is 7%, which is higher than the range of edge lithium plating probabilities in Examples 45 to 50, meaning the edge lithium plating probability of Example 52 is significantly higher than that of Examples 45 to 50. Therefore, it can be seen that H2 / H1 in Example 52 exceeds the parameter range of this application and cannot take into account the three performance parameters of electrode cutting edge powder loss rate, wetting performance improvement rate and edge lithium plating probability.

[0078] As shown in Table 5, in Examples 39 to 50, H3 / H1 did not exceed the parameter range of this application. Its electrode cutting edge powder shedding rate was 0, the wetting performance improvement rate was 10.3%-21%, and the edge lithium plating probability was 0-0.2%. Therefore, H3 / H1 did not exceed the parameter range of this application, and it can balance the three performance parameters of electrode cutting edge powder shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0079] As shown in Table 5, in Example 53, H3 / H1 exceeds the parameter range of this application. The electrode edge shedding rate of Example 53 is 0, falling within the range of electrode edge shedding rates in Examples 45 to 50. The wetting performance improvement rate of Example 53 is 0.7%, lower than the range of wetting performance improvement rates in Examples 45 to 50, meaning the wetting performance improvement rate of Example 53 is significantly lower than that of Examples 45 to 50. The edge lithium plating probability of Example 53 is 0, falling within the range of edge lithium plating probabilities in Examples 45 to 50. Therefore, it is evident that H3 / H1 in Example 53 exceeds the parameter range of this application, failing to simultaneously achieve the three performance parameters of electrode edge shedding rate, wetting performance improvement rate, and edge lithium plating probability.

[0080] As shown in Table 5, in Example 54, H3 / H1 exceeds the parameter range of this application. The electrode cutting edge dust loss rate of Example 54 is 0, which falls within the range of electrode cutting edge dust loss rates in Examples 45 to 50. The wetting performance improvement rate of Example 54 is 12.1%, which falls within the range of wetting performance improvement rates in Examples 45 to 50. The edge lithium plating probability of Example 54 is 10, which is higher than the range of edge lithium plating probabilities in Examples 45 to 50, meaning that the edge lithium plating probability of Example 54 is significantly higher than that of Examples 45 to 50. Therefore, it is evident that H3 / H1 in Example 54 exceeds the parameter range of this application, and cannot simultaneously achieve the three performance parameters of electrode cutting edge dust loss rate, wetting performance improvement rate, and edge lithium plating probability.

[0081] Referring to Figure 4, on a plane parallel to the first direction M and the third direction P, the sum of the areas of the slots of the second groove 1221 on the active layer 12 located on the side of the current collector 11 in the second direction N is S1 mm. 2 The area of ​​the coating part 112 is S2 mm. 2 S1 and S2 satisfy: 0.04 ≤ S1 / S2 ≤ 0.15. That is, the sum of the areas S1 mm of the openings of the second groove 1221 on the active layer 12 on the side of the current collector 11 in the second direction N. 2 The area S2 mm of the coating part 112 2 The ratio is controlled within the range of 0.04 to 0.15. For example, the sum of the areas of the slots S1 mm of the slots 1221 on the active layer 12 on the side of the current collector 11 in the second direction N. 2 The area S2 mm of the coating part 112 2 The ratio can be one of 0.04, 0.06, 0.08, 0.1, 0.12, 0.14, or 0.15, or within any combination of these values. The specific values ​​of the ratio given above are merely illustrative, and any value within the range of 0.04 to 0.15 is within the scope of protection of this application.

[0082] Table 6 shows the parameters and test results for Examples 55-62.

[0083] As shown in Table 6, in Examples 55 to 60, S1 / S2 did not exceed the parameter range of this application, with a powder shedding rate of 0 at the electrode cutting edge and a wetting performance improvement rate of 2.2%-13%. Therefore, S1 / S2 did not exceed the parameter range of this application, and both the powder shedding rate at the electrode cutting edge and the wetting performance improvement rate can be considered.

[0084] As shown in Table 6, in Example 61, S1 / S2 exceeds the parameter range of this application. The electrode cutting edge dust loss rate of Example 61 is 0, which falls within the range of electrode cutting edge dust loss rates in Examples 55 to 60. The wetting performance improvement rate of Example 61 is 0.2%, lower than the range of wetting performance improvement rates in Examples 55 to 60; that is, the wetting performance improvement rate of Example 61 is lower than that of Examples 55 to 60. Therefore, it is evident that S1 / S2 in Example 61 exceeds the parameter range of this application, and it is impossible to simultaneously achieve both the electrode cutting edge dust loss rate and the wetting performance improvement rate.

[0085] As shown in Table 6, in Example 62, S1 / S2 exceeds the parameter range of this application. The electrode cutting edge dust loss rate of Example 62 is 2, which is higher than the range of electrode cutting edge dust loss rates in Examples 55 to 60, meaning the electrode cutting edge dust loss rate of Example 62 is significantly higher than that of Examples 55 to 60. The wetting performance improvement rate of Example 62 is 1.5%, which is lower than the range of wetting performance improvement rates in Examples 55 to 60, meaning the wetting performance improvement rate of Example 62 is significantly lower than that of Examples 55 to 60. Therefore, it is evident that S1 / S2 in Example 62 exceeds the parameter range of this application, making it impossible to simultaneously achieve both the electrode cutting edge dust loss rate and the wetting performance improvement rate.

[0086] Referring to Figure 4, on the third direction P, the width of the edge portion 121 located on any side of the main body 122 is T1 mm, and T1 and L3 satisfy T1 / L3≤2. That is, the ratio of the width T1 mm of the edge portion 121 located on any side of the main body 122 to the distance L3 mm between the central axes of the openings of any two adjacent second grooves 1221 is controlled to be less than or equal to 2. For example, the ratio of the width T1 mm of the edge portion 121 located on any side of the main body 122 to the distance L3 mm between the central axes of the openings of any two adjacent second grooves 1221 can be one of 0.05, 0.1, 0.2, 0.4, 0.5, 0.6, 1, 1.2, 1.4, 1.6, 1.8 or 2, or within any combination of two of these values. The specific values ​​of this ratio are given above as examples only, and any value within the range of less than or equal to 2 is within the protection scope of this application.

[0087] Table 7 Parameters and test results for Examples 63-70

[0088] As shown in Table 7, in Examples 63 to 68, T1 / L3 did not exceed the parameter range of this application, with a powder shedding rate of 0 at the electrode cutting edge and a wetting performance improvement rate of 3.6%-12.9%. Therefore, T1 / L3 does not exceed the parameter range of this application and can balance both the electrode cutting edge powder shedding rate and the wetting performance improvement rate.

[0089] As shown in Table 7, in Example 69, T1 / L3 exceeds the parameter range of this application. The electrode cutting edge dust loss rate of Example 69 is 4%, which is higher than the range of electrode cutting edge dust loss rates in Examples 63 to 68. In other words, the electrode cutting edge dust loss rate of Example 69 is significantly higher than that of Examples 63 to 68. The wetting performance improvement rate of Example 69 is 12.9%, which is within the range of wetting performance improvement rates in Examples 63 to 68. Therefore, it is evident that T1 / L3 of Example 69 exceeds the parameter range of this application, making it impossible to simultaneously achieve both electrode cutting edge dust loss rate and wetting performance improvement rate.

[0090] As shown in Table 7, in Example 70, T1 / L3 exceeds the parameter range of this application. The electrode cutting edge dust loss rate of Example 70 is 2%, which is higher than the range of electrode cutting edge dust loss rates in Examples 63 to 68, meaning the electrode cutting edge dust loss rate of Example 70 is significantly higher than that of Examples 63 to 68. The wetting performance improvement rate of Example 70 is 1.8%, which is lower than the range of wetting performance improvement rates in Examples 63 to 68, meaning the wetting performance improvement rate of Example 70 is significantly lower than that of Examples 63 to 68. Therefore, it is evident that the T1 / L3 of Example 70 exceeds the parameter range of this application, making it impossible to simultaneously achieve both the electrode cutting edge dust loss rate and the wetting performance improvement rate.

[0091] The powder shedding rate at the electrode cutting edges in the tables above can be obtained through the following test method: Charge and discharge the individual cells under the same conditions, allow them to stand for a period of time, disassemble the individual cells, and then calculate the amount of powder shedding at the electrode corners. The amount of powder shedding is calculated as the cumulative area of ​​the detached area, expressed as 0.01 cm². 2 The ratio of the amount of powder shed to the total area of ​​the electrode is the powder shedding rate at the electrode cutting edge. A smaller powder shedding rate at the electrode cutting edge indicates a better degree of powder shedding optimization for the individual cell; a moderate powder shedding rate indicates a medium degree of powder shedding optimization for the individual cell; and a larger powder shedding rate indicates a worse degree of powder shedding optimization for the individual cell.

[0092] The wetting performance improvement rates in the tables above can be obtained through the following testing method. Add 0.03 wt.% phosphor to the electrolyte, and inject the electrolyte into the single cell according to the process specifications, allowing it to stand at high temperature. Disassemble the single cell and remove the separator. Place the separator in a UV light box to observe the fluorescence position and record the results. Analyze the wetting path and wetting degree, and observe the phosphor wetting situation. Under the same wetting time, the smaller the wetting area after standing, the worse the wetting performance; the larger the wetting area after standing, the better the wetting performance. The ratio of the separator's wetting area to its total area is the wetting efficiency. Obtain the wetting efficiency of a control group. Subtract the wetting efficiency of the control group from the wetting efficiency of Examples 1 to 70 to obtain the wetting performance improvement rate of Examples 1 to 70.

[0093] The edge lithium plating probabilities in the tables above can be obtained by testing using the following method: Perform a lithium plating test on a single battery cell, then disassemble the cell under full charge and observe the lithium plating on the negative electrode. The ratio of the lithium plating area to the total area of ​​the negative electrode is the edge lithium plating probability.

[0094] The above provides a detailed description of a single-cell battery provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the technical solutions and core ideas of this application. Those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A single-cell battery having intersecting first direction (M), second direction (N), and third direction (P), comprising: Shell (101); as well as An electrode assembly (102) is disposed within the housing (101), and the electrode assembly (102) includes an electrode plate (1). The electrode (1) includes: A current collector (11), the current collector (11) comprising an electrode tab (111) and a coating portion (112), the electrode tab (111) being disposed on at least one side of the coating portion (112) in the first direction (M); and An active layer (12) is disposed on at least one side of the coated portion (112) in the second direction (N). The active layer (12) includes an edge portion (121) and a main body portion (122), wherein the edge portion (121) is disposed on at least one side of the main body portion (122) in the third direction (P). The edge portion (121) has a plurality of first grooves (1211) on the side away from the current collector (11). The plurality of first grooves (1211) are arranged at intervals along the third direction (P) and the first direction (M). The surface of the main body (122) away from the current collector (11) is provided with a plurality of second grooves (1221), the plurality of second grooves (1221) are arranged at intervals along the third direction (P), and the second grooves (1221) extend along the first direction (M).

2. The single-cell battery according to claim 1, wherein, The edge portion (121) has a first thinning region (1212) formed thereon, the first thinning region (1212) being located on at least one side of the edge portion (121) in the first direction (M), and the first groove (1211) being located outside the first thinning region (1212); and The main body (122) has a second thinning area (1222) located on at least one side of the main body (122) in the first direction (M), and the second groove (1221) is located outside the second thinning area (1222).

3. The single-cell battery according to claim 2, wherein, The first thinning region (1212) and the second thinning region (1222) are both adjacent to the tab portion (111).

4. The single-cell battery according to claim 1, wherein, The edge portion (121) is disposed on both sides of the main body portion (122) on the third direction (P).

5. The single-cell battery according to claim 1, wherein, The current collector (11) has active layers (12) on both sides in the second direction (N), and the active layers (12) on both sides of the current collector (11) in the second direction (N) are provided with the first groove (1211). The first groove (1211) on the active layer (12) located on one side of the current collector (11) in the second direction (N) is offset from the first groove (1211) on the active layer (12) located on the other side of the current collector (11) in the second direction (N) in the second direction (N).

6. The single-cell battery according to claim 1, wherein, The orthographic projection shape of the opening of the first groove (1211) on the coating part (112) is circular, and the diameter of the opening of the first groove (1211) is W1 mm. In the first direction (M), the center distance between the openings of two adjacent first slots (1211) is L1 mm; and On the third direction (P), the center distance between the openings of two adjacent first slots (1211) is L2 mm, and L1 and W1 satisfy: 1.3≤L1 / W1≤50, and / or, L2 and W1 satisfy: 1.3≤L2 / W1≤50.

7. The single-cell battery according to claim 6, wherein, The condition W1 satisfies: 0.04≤W1≤0.

15.

8. The single-cell battery according to claim 6, wherein, The L1 satisfies: 0.2≤L1≤2, and / or the L2 satisfies: 0.2≤L2≤2.

9. The single-cell battery according to claim 6, wherein, On a plane parallel to the first direction (M) and the third direction (P), the minimum distance between the center of the opening of the first groove (1211) and the tab (111) in the first direction (M) is P1 mm, wherein P1 satisfies: 1≤P1≤5.

10. The single-cell battery according to claim 1, wherein, The orthographic projection shape of the opening of the second groove (1221) onto the coating portion (112) is rectangular; and On the third direction (P), the width of the opening of the second groove (1221) is W2 mm, and the distance between the central axes of the openings of two adjacent second grooves (1221) is L3 mm. W2 and L3 satisfy: 1.3≤L3 / W2≤50.

11. The single-cell battery according to claim 10, wherein, On a plane parallel to the first direction (M) and the third direction (P), the minimum distance between the opening of the second groove (1221) and the tab (111) in the first direction (M) is P2 mm, wherein P2 satisfies: 1≤P2≤5.

12. The single-cell battery according to claim 10, wherein, The W2 satisfies: 0.04≤W2≤0.15, and / or the L3 mm satisfies: 0.2≤L3≤2.

13. The single-cell battery according to claim 1, wherein, The thickness of the active layer (12) in the second direction (N) is H1 mm; The depth of the first groove (1211) in the second direction (N) is H2 mm; and The depth of the second groove (1221) in the second direction (N) is H3mm. Wherein H2 and H1 satisfy: 0.05≤H2 / H1≤0.5, and / or, H3 and H1 satisfy: 0.05≤H3 / H1≤0.

5.

14. The single-cell battery according to claim 1 or 11, wherein, On a plane parallel to the first direction (M) and the third direction (P), The sum of the areas of the openings of the second groove (1221) on the active layer (12) located on one side of the current collector (11) in the second direction (N) is S1 mm. 2 ,as well as The area of ​​the coating portion (112) is S2 mm. 2 Wherein S1 and S2 satisfy: 0.04≤S1 / S2≤0.

15.

15. The single-cell battery according to claim 10 or 11, wherein, On the third direction (P), the width of the edge portion (121) located on any side of the main body portion (122) is T1 mm, and T1 and L3 satisfy: T1 / L3≤2.

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