Battery cell, battery device, and electric device

Abstract

This application provides a battery cell, a battery device, and an electrical device, belonging to the field of battery technology. The battery cell includes a casing and an electrode assembly. The electrode assembly includes a main body and a plurality of first tabs. The plurality of first tabs are connected to one end of the main body in a first direction and are stacked. The main body includes a plurality of electrode segments stacked along a second direction. The plurality of electrode segments include a plurality of first electrode segments with the same polarity. The first end of each first tab is connected to a first electrode segment. The main body has a first stacked region and two second stacked regions located on both sides of the first stacked region in the second direction. The sum of the cross-sectional areas of the first ends of all the first tabs in the first stacked region is greater than the sum of the cross-sectional areas of the first ends of all the first tabs in the two second stacked regions, so as to improve the overcurrent requirement of the first electrode segment at the center of the main body and reduce the risk of lithium plating caused by the poor electrolyte wetting effect of the inner electrode segments compared with the outer electrode segments.

Description

Technical Field

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

[0002] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, power batteries, as the power source, play an irreplaceable and crucial role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also increasing day by day.

[0003] In battery technology, a battery cell includes a casing and an electrode assembly housed within the casing. To improve the energy density of a battery cell, the electrode assembly is usually designed as a wound or stacked structure to increase its volume. However, battery cells with this structure are prone to risks such as internal lithium plating during use, which is detrimental to improving the reliability of the battery cell. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, including a housing and at least one electrode assembly; the electrode assembly is housed within the housing, the electrode assembly includes a main body and a plurality of first tabs, the plurality of first tabs being connected to one end of the main body in a first direction and stacked thereon, the main body including a plurality of electrode segments stacked along a second direction, the plurality of electrode segments including a plurality of first electrode segments of the same polarity, each first tab being connected to one first electrode segment, and the first tab having a first end connected to the corresponding first electrode segment, the first direction being perpendicular to the second direction; wherein, the main body has a first stacked region and two second stacked regions, the first stacked region being located between the two second stacked regions in the second direction, the difference between the number of first electrode segments in the first stacked region and the sum of the number of first electrode segments in the two second stacked regions being less than or equal to 1, and the number of first electrode segments in the two second stacked regions being the same, and in the same cross-section perpendicular to the first direction, the sum of the cross-sectional areas of the first ends of all the first tabs in the first stacked region being greater than the sum of the cross-sectional areas of the first ends of all the first tabs in the two second stacked regions.

[0006] In the above technical solution, one end of the main body of the electrode assembly is connected to a plurality of stacked first electrode tabs, and each first electrode tab is connected to a first electrode segment, such that the connection position of the stacked first electrode tabs to the main body is arranged along the second direction. The first stacked region is located between two second stacked regions in the second direction. The difference between the number of first electrode segments in the first stacked region and the sum of the number of first electrode segments in the two second stacked regions is less than or equal to 1, and the number of first electrode segments in the two second stacked regions is the same. This ensures that the first electrode segment located in the first stacked region is the first electrode segment closest to the center of the electrode assembly among the plurality of first electrode segments stacked along the second direction of the main body. This is achieved by setting the sum of the cross-sectional areas of the first ends of the first electrode tabs on all the first electrode segments in the first stacked region to be greater than the sum of the cross-sectional areas of the first electrode segments in the two second stacked regions. The sum of the cross-sectional areas of the first ends of the first tabs on the first electrode segment makes the sum of the cross-sectional areas of the roots of all the first tabs in the first stacked region greater than the sum of the cross-sectional areas of the roots of all the first tabs in the two second stacked regions. This makes the area of ​​the first electrode segment near the center of the electrode assembly in the main body that conducts current through the first tab larger than the area of ​​the first electrode segment located on the outer region of the electrode assembly in the main body that conducts current through the first tab. This improves the current path and current demand of the first electrode segment near the center of the electrode assembly in the main body, thereby alleviating the phenomenon of limited electron transport path of the first electrode segment near the center of the electrode assembly through the first tab. In turn, it can effectively reduce the risk of lithium plating caused by poor electrolyte wetting effect of the electrode segments on the inner side of the main body compared with the outer electrode segments, thereby improving the reliability of the battery cell.

[0007] In some embodiments, the electrode assembly is a wound structure, and the winding center axis of the electrode assembly extends along the first direction; wherein, the main body further includes a plurality of bent segments, the plurality of bent segments including a first bent segment, the first bent segment connecting two adjacent first electrode segments along the winding direction of the electrode assembly, and the first bent segment and the first electrode segment are alternately arranged.

[0008] In the above technical solution, by setting the electrode assembly as a wound structure, a first electrode segment is formed between two adjacent first bending segments in the winding direction of the electrode assembly. The electrode assembly with this structure is beneficial to improving the energy density of the battery cell.

[0009] In some embodiments, the first electrode segment in the first stacked region and the first electrode segments in the two second stacked regions are all connected to the first electrode tab; or, along the second direction, the first electrode segments located on one side of the center position of the electrode assembly are all connected to the first electrode tab.

[0010] In the above technical solution, by connecting the first electrode segments located in the first stacked region and the two second stacked regions to the first electrode tabs, the first electrode segments on both sides of the main body located at the center of the electrode assembly in the second direction are connected to the first electrode tabs. This improves the overall current flow requirements and current flow path of the electrode assembly, thereby further reducing the risk of lithium plating during use. By connecting the first electrode segments on one side of the first electrode assembly located at the center of the electrode assembly in the second direction to the first electrode segments, the electrode assembly has a structure with multiple first electrode tabs on one side in the second direction. This reduces the difficulty of setting multiple stacked first electrode tabs at one end of the main body, thereby reducing the manufacturing difficulty of the electrode assembly.

[0011] In some embodiments, in two adjacent first tabs, in the same cross-section perpendicular to the first direction, along the second direction, the cross-sectional area of ​​the first end of the first tab closer to the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first tab farther from the center of the electrode assembly.

[0012] In the above technical solution, by setting the cross-sectional area of ​​the first end of the first electrode tab near the center of the electrode assembly in a plurality of first electrode tabs stacked in the second direction to be greater than the cross-sectional area of ​​the first end of the first electrode tab far from the center of the electrode assembly, the cross-sectional area of ​​the first end of the first electrode tab on the first electrode segment inside the electrode assembly gradually decreases from the first electrode tab on the first electrode segment outside the electrode assembly. This achieves that the sum of the cross-sectional areas of the first ends of the first electrode tabs on all the first electrode segments in the first stacked region is greater than the sum of the cross-sectional areas of the first ends of the first electrode tabs on all the first electrode segments in the two second stacked regions, which helps to reduce the manufacturing difficulty of the electrode assembly.

[0013] In some embodiments, in two adjacent first tabs, in the same cross section perpendicular to the first direction, the width of the first end of the first tab closer to the center of the electrode assembly in the third direction is greater than the width of the first end of the first tab farther from the center of the electrode assembly in the third direction, wherein the first direction, the second direction, and the third direction are perpendicular to each other.

[0014] In the above technical solution, in two adjacent first tabs, by setting the width of the first end of the first tab near the center of the electrode assembly in the third direction to be greater than the width of the first end of the first tab away from the center of the electrode assembly in the third direction, the width of the first end of the first tab on the first electrode segment inside the electrode assembly gradually decreases from the first tab on the first electrode segment outside the electrode assembly. This achieves a structure in which the cross-sectional area of ​​the first end of the first tab near the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first tab away from the center of the electrode assembly. The structure is simple and easy to manufacture.

[0015] In some embodiments, within the same cross-section perpendicular to the first direction, the first ends of the plurality of first tabs have the same thickness in the second direction.

[0016] In the above technical solution, by setting the thickness of the first ends of multiple first electrodes in the second direction to be the same, on the one hand, the forming difficulty of multiple first electrodes can be reduced, which is conducive to reducing the manufacturing difficulty of electrode components. On the other hand, it is convenient to set first electrodes with different cross-sectional areas by adjusting the width of the first ends of the first electrodes in the third direction, which is conducive to improving the processing accuracy of the cross-sectional area of ​​the first ends of multiple first electrodes.

[0017] In some embodiments, in two adjacent first tabs, the first tab closer to the center of the electrode assembly extends along the third direction beyond the two ends of the first tab farther from the center of the electrode assembly in the third direction.

[0018] In the above technical solution, by setting the first tab near the center of the electrode assembly to extend beyond the two ends of the first tab far from the center of the electrode assembly in the third direction, it is convenient to stack multiple first tabs on each other, which helps to reduce the processing difficulty of the electrode assembly and improve the processing quality of the electrode assembly. On the other hand, it can alleviate the misalignment between two adjacent first tabs, thereby reducing the total misalignment of multiple first tabs in the third direction. This reduces the risk of short circuit caused by the large misalignment of multiple first tabs in the third direction, thus improving the reliability of the battery cell.

[0019] In some embodiments, in two adjacent first tabs, in the same cross-section perpendicular to the first direction, the thickness of the first end of the first tab closer to the center of the electrode assembly in the second direction is greater than the thickness of the first end of the first tab farther from the center of the electrode assembly in the second direction.

[0020] In the above technical solution, in two adjacent first tabs, by setting the thickness of the first end of the first tab near the center of the electrode assembly in the second direction to be greater than the thickness of the first end of the first tab away from the center of the electrode assembly in the second direction, the thickness of the first end of the first tab on the first electrode segment inside the electrode assembly gradually decreases in the second direction from the first tab on the first electrode segment outside the electrode assembly. This achieves a structure in which the cross-sectional area of ​​the first end of the first tab near the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first tab away from the center of the electrode assembly. The structure is simple and easy to manufacture.

[0021] In some embodiments, within the same cross-section perpendicular to the first direction, the first ends of a plurality of first tabs have the same width in a third direction, and the first direction, the second direction, and the third direction are perpendicular to each other.

[0022] In the above technical solution, by setting the width of the first ends of multiple first electrodes in the third direction to be the same, it is possible to achieve a structure in which the cross-sectional area of ​​the first end of the first electrode near the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first electrode far from the center of the electrode assembly, while also achieving a structure in which multiple first electrodes have equal width in the third direction. On the one hand, multiple first electrodes can be formed by cutting the edge once, which is beneficial to improving the processing efficiency of multiple first electrodes. On the other hand, it can improve the regularity of the multiple first electrodes stacked together.

[0023] In some embodiments, all the first pole segments in the first stacked region are connected to the first pole tabs, and only one of the two second stacked regions has all the first pole segments connected to the first pole tabs; wherein, in the same cross-section perpendicular to the first direction, the first ends of the plurality of first pole tabs have the same thickness in the second direction, and the first ends of the plurality of first pole tabs have the same width in the third direction, and the first direction, the second direction and the third direction are perpendicular to each other.

[0024] In the above technical solution, by providing first tabs on all first electrode segments in the first stacked region, and only providing first tabs on the first electrode segments in one of the two second stacked regions, the main body, which is a structure where multiple first electrode segments near the center of the electrode assembly are connected to first tabs, and the outer region of the electrode assembly, which is a structure where only one side of the first electrode segments is connected to first tabs, makes the number of first tabs in the main body near the center of the electrode assembly greater than the number of first tabs in the outer region of the electrode assembly. Thus, by setting the first ends of multiple first tabs of the electrode assembly to have the same thickness in the second direction and the same width in the third direction, the sum of the cross-sectional areas of the first ends of the first tabs on the first electrode segments in the first stacked region is greater than the sum of the cross-sectional areas of the first ends of the first tabs on the first electrode segments in the two second stacked regions. This facilitates the forming of multiple first tabs and reduces the stacking difficulty of multiple first tabs, thereby reducing the manufacturing difficulty of the electrode assembly.

[0025] In some embodiments, the electrode assembly is a stacked structure, and the plurality of electrode segments further includes a plurality of second electrode segments with the same polarity. The second electrode segments and the first electrode segments are stacked and alternately arranged along the second direction. One of the first electrode segments and the second electrode segments is a positive electrode and the other is a negative electrode. Each first electrode segment is connected to a first tab. In two adjacent first tabs, in the same cross-section perpendicular to the first direction, along the second direction, the cross-sectional area of ​​the first end of the first tab closer to the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first tab farther from the center of the electrode assembly.

[0026] In the above technical solution, by setting the electrode assembly as a stacked structure, the positive and negative electrode sheets stacked along the second direction constitute multiple electrode segments of the electrode assembly. Electrode assemblies with this structure can increase their thickness in the second direction according to actual needs to meet different application requirements. Furthermore, each first electrode segment in the main body of the stacked electrode assembly is connected to a first tab. By setting the cross-sectional area of ​​the first end of the first tab closest to the center of the electrode assembly to be larger than the cross-sectional area of ​​the first end of the first tab furthest from the center of the electrode assembly, the cross-sectional area of ​​the first tab on the first electrode segment inside the electrode assembly gradually decreases from the first tab on the first electrode segment outside the electrode assembly. This achieves a situation where the sum of the cross-sectional areas of the first ends of the first tabs on the first electrode segments within the first stacked region is greater than the sum of the cross-sectional areas of the first ends of the first tabs on the first electrode segments within the two second stacked regions, which helps to reduce the manufacturing difficulty of the electrode assembly.

[0027] In some embodiments, in two adjacent first tabs, in the same cross section perpendicular to the first direction, the width of the first end of the first tab closer to the center of the electrode assembly in the third direction is greater than the width of the first end of the first tab farther from the center of the electrode assembly in the third direction, wherein the first direction, the second direction, and the third direction are perpendicular to each other.

[0028] In the above technical solution, in two adjacent first tabs, by setting the width of the first end of the first tab near the center of the electrode assembly in the third direction to be greater than the width of the first end of the first tab away from the center of the electrode assembly in the third direction, the width of the first end of the first tab on the first electrode segment inside the electrode assembly gradually decreases from the first tab on the first electrode segment outside the electrode assembly. This achieves a structure in which the cross-sectional area of ​​the first end of the first tab near the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first tab away from the center of the electrode assembly. The structure is simple and easy to manufacture.

[0029] In some embodiments, within the same cross-section perpendicular to the first direction, the first ends of the plurality of first tabs have the same thickness in the second direction.

[0030] In the above technical solution, by setting the thickness of the first ends of multiple first electrodes in the second direction to be the same, on the one hand, the forming difficulty of multiple first electrodes can be reduced, which is conducive to reducing the manufacturing difficulty of electrode components. On the other hand, it is convenient to set first electrodes with different cross-sectional areas by adjusting the width of the first ends of the first electrodes in the third direction, which is conducive to improving the processing accuracy of the cross-sectional area of ​​the first ends of multiple first electrodes.

[0031] In some embodiments, in two adjacent first tabs, the first tab closer to the center of the electrode assembly extends along the third direction beyond the two ends of the first tab farther from the center of the electrode assembly in the third direction.

[0032] In the above technical solution, by setting the first tab near the center of the electrode assembly to extend beyond the two ends of the first tab far from the center of the electrode assembly in the third direction, it is convenient to stack multiple first tabs on each other, which helps to reduce the processing difficulty of the electrode assembly and improve the processing quality of the electrode assembly. On the other hand, it can alleviate the misalignment between two adjacent first tabs, thereby reducing the total misalignment of multiple first tabs in the third direction. This reduces the risk of short circuit caused by the large misalignment of multiple first tabs in the third direction, thus improving the reliability of the battery cell.

[0033] In some embodiments, in two adjacent first tabs, in the same cross-section perpendicular to the first direction, the thickness of the first end of the first tab closer to the center of the electrode assembly in the second direction is greater than the thickness of the first end of the first tab farther from the center of the electrode assembly in the second direction.

[0034] In the above technical solution, in two adjacent first tabs, by setting the thickness of the first end of the first tab near the center of the electrode assembly in the second direction to be greater than the thickness of the first end of the first tab away from the center of the electrode assembly in the second direction, the thickness of the first end of the first tab on the first electrode segment inside the electrode assembly gradually decreases in the second direction from the first tab on the first electrode segment outside the electrode assembly. This achieves a structure in which the cross-sectional area of ​​the first end of the first tab near the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first tab away from the center of the electrode assembly. The structure is simple and easy to manufacture.

[0035] In some embodiments, within the same cross-section perpendicular to the first direction, the first ends of a plurality of first tabs have the same width in a third direction, and the first direction, the second direction, and the third direction are perpendicular to each other.

[0036] In the above technical solution, by setting the width of the first ends of multiple first electrodes in the third direction to be the same, it is possible to achieve a structure in which the cross-sectional area of ​​the first end of the first electrode near the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first electrode far from the center of the electrode assembly, while also achieving a structure in which multiple first electrodes have equal width in the third direction. On the one hand, multiple first electrodes can be formed by cutting the edge once, which is beneficial to improving the processing efficiency of multiple first electrodes. On the other hand, it can improve the regularity of the multiple first electrodes stacked together.

[0037] In some embodiments, the first electrode segment includes a first current collector and a first active material layer disposed on at least one side of the first current collector, and the first electrode tab is connected to one end of the first current collector in the first direction; wherein the first electrode tab is integrally formed with the first current collector; or, the first electrode tab is separately disposed from the first current collector.

[0038] In the above technical solution, by setting the first electrode and the first current collector as an integrally formed structure, which is made of the same foil material through an integral molding process, the connection stability and reliability between the first electrode and the first current collector are improved, thereby reducing the risk of connection failure. By setting the first electrode and the first current collector as separate components, the size of the first electrode is not constrained by the first current collector, allowing for the setting of different sizes of first electrodes according to actual needs, thus improving the production flexibility of the electrode assembly.

[0039] In some embodiments, the positive electrode active material of the electrode assembly includes lithium transition metal oxide, and the length of the main body in the first direction is L, satisfying 100mm≤L≤200mm; or, the positive electrode active material of the electrode assembly includes lithium phosphate, and the length of the main body in the first direction is L, satisfying 200mm≤L≤350mm.

[0040] In the above technical solution, when the positive electrode active material of the electrode assembly includes lithium transition metal oxide and the length of the main body of the electrode assembly in the first direction is 100mm to 200mm, or when the positive electrode active material of the electrode assembly includes lithium phosphate and the length of the main body of the electrode assembly in the first direction is 200mm to 3500mm, the overcurrent demand of the electrode segment of the main body is greater. Therefore, setting the sum of the cross-sectional areas of the first ends of the first tabs on all the first electrode segments in the first stacked region to be greater than the sum of the cross-sectional areas of the first ends of the first tabs on all the first electrode segments in the two second stacked regions can effectively alleviate the risk of lithium plating caused by poor electrolyte wetting effect of the inner electrode segments of the electrode assembly, thereby improving the reliability of the battery cell.

[0041] In some embodiments, the positive active material of the electrode assembly comprises lithium transition metal oxide, and L further satisfies that 110mm≤L≤180mm.

[0042] In the above technical solution, by setting the length of the main body of the electrode assembly, which is composed of lithium transition metal oxide as the positive electrode active material, to 110 mm to 180 mm in the first direction, it is possible to improve the energy density of the electrode assembly while reducing the manufacturing difficulty of the electrode assembly, and to alleviate the problem of the difficulty in electrolyte wetting of the inner electrode segment of the electrode assembly.

[0043] In some embodiments, the positive active material of the electrode assembly comprises lithium transition metal oxide, and L further satisfies that 120mm≤L≤160mm.

[0044] In the above technical solution, by further setting the length of the main body of the electrode assembly, which includes lithium transition metal oxide as the positive electrode active material, in the first direction to 120mm to 160mm, it is possible to improve the energy density of the electrode assembly while further reducing the manufacturing difficulty of the electrode assembly, and further alleviate the phenomenon that the electrolyte wetting of the inner electrode segment of the electrode assembly is difficult.

[0045] In some embodiments, the positive electrode active material of the electrode assembly includes lithium phosphate, and L further satisfies that 210mm≤L≤340mm.

[0046] In the above technical solution, by setting the length of the main body of the positive electrode active material, including the lithium phosphate-containing electrode assembly, in the first direction to 210mm to 340mm, it is possible to increase the energy density of the electrode assembly while reducing the manufacturing difficulty of the electrode assembly, and to alleviate the phenomenon that the electrolyte wetting of the inner electrode segment of the electrode assembly is difficult.

[0047] In some embodiments, the positive electrode active material of the electrode assembly includes lithium phosphate, and L further satisfies that 220mm≤L≤330mm.

[0048] In the above technical solution, by further setting the length of the main body of the positive electrode active material, including the lithium phosphate-containing electrode assembly, in the first direction to 220mm to 330mm, it is possible to improve the energy density of the electrode assembly while further reducing the manufacturing difficulty of the electrode assembly, and further alleviate the phenomenon that the electrolyte wetting of the inner electrode segment of the electrode assembly is difficult.

[0049] In some embodiments, the width of the main body in the third direction is W, satisfying 200mm≤W≤400mm, and the first direction, the second direction and the third direction are perpendicular to each other.

[0050] In the above technical solution, by setting the width of the main body of the electrode assembly in the third direction to 200mm to 400mm, the size of the electrode assembly can be increased to improve the energy density of the battery cell. Since the overcurrent demand of the electrode segments in the main body is greater when the width of the main body of the electrode assembly in the third direction is 200mm to 400mm, the structure of setting the sum of the cross-sectional areas of the first ends of the first tabs on all the first electrode segments in the first stacked region to be greater than the sum of the cross-sectional areas of the first ends of the first tabs on all the first electrode segments in the two second stacked regions can effectively alleviate the risk of lithium plating caused by poor electrolyte wetting effect of the inner electrode segments of the electrode assembly, thereby improving the reliability of the battery cell.

[0051] In some embodiments, 200mm ≤ W ≤ 350mm.

[0052] In the above technical solution, by further setting the width of the main body of the electrode assembly in the third direction to 200mm to 350mm, the energy density of the electrode assembly can be increased while the manufacturing difficulty of the electrode assembly can be further reduced, and the phenomenon that the electrolyte wetting of the inner electrode segment of the electrode assembly is difficult can be further alleviated.

[0053] In some embodiments, 220mm ≤ W ≤ 340mm.

[0054] In the above technical solution, by further setting the width of the main body of the electrode assembly in the third direction to 220mm to 340mm, the energy density of the electrode assembly can be increased while the manufacturing difficulty of the electrode assembly can be further reduced, and the phenomenon that the electrolyte wetting of the inner electrode segment of the electrode assembly is difficult can be further alleviated.

[0055] In some embodiments, the electrode assembly further includes a plurality of second tabs connected to one end of the main body in the first direction and stacked thereon. The plurality of electrode segments further includes a plurality of second electrode segments with the same polarity, the polarities of the second electrode segments being opposite to those of the first electrode segments. Each second tab is connected to one second electrode segment, and the second tab has a second end connected to the corresponding second electrode segment. The difference between the number of second electrode segments in the first stacked region and the sum of the number of second electrode segments in the two second stacked regions is less than or equal to 1, and the number of second electrode segments in the two second stacked regions is the same. In the same cross-section perpendicular to the first direction, the sum of the cross-sectional areas of the second ends of all the second tabs in the first stacked region is greater than the sum of the cross-sectional areas of the second ends of all the second tabs in the two second stacked regions.

[0056] In the above technical solution, one end of the main body of the electrode assembly in the first direction is further connected to a plurality of stacked second electrodes. Each second electrode is connected to a second electrode segment, and the polarity of the second electrode segment is opposite to that of the first electrode segment. This allows the second electrodes and the first electrodes to cooperate in inputting or outputting electrical energy into the electrode assembly. Furthermore, the connection positions of the stacked second electrodes to the main body are also arranged along the second direction. Specifically, by setting the sum of the cross-sectional areas of the second ends of the second electrodes on all the second electrode segments in the first stacked region to be greater than the sum of the cross-sectional areas of the second ends of the second electrodes on all the second electrode segments in two second stacked regions, the sum of the cross-sectional areas of the roots of all the second electrodes in the first stacked region is greater than... The sum of the cross-sectional areas of the roots of all the second tabs in the two second stacked regions is used to make the area of ​​the second electrode segment near the center of the electrode assembly in the main body larger than the area of ​​the second electrode segment in the outer region of the electrode assembly in the main body. This can improve the current path and current demand of the second electrode segment near the center of the electrode assembly in the main body, thereby alleviating the phenomenon of limited electron transport path of the second electrode segment near the center of the electrode assembly through the second tab. In addition, it can further reduce the risk of lithium plating caused by poor electrolyte wetting effect of the electrode segment on the inner side of the main body compared with the outer electrode segment, thereby further improving the reliability of the battery cell.

[0057] Secondly, embodiments of this application also provide a battery device, including the aforementioned battery cell.

[0058] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery cell, wherein the battery cell is used to provide electrical energy. Attached Figure Description

[0059] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0060] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0061] Figure 2 Exploded views of the structure of the battery device provided in some embodiments of this application;

[0062] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0063] Figure 4 Exploded views of the structure of a single battery cell provided in some embodiments of this application;

[0064] Figure 5 A front view of the electrode assembly of a battery cell provided in a second direction for some embodiments of this application;

[0065] Figure 6 A front view of the electrode assembly of a battery cell provided in a first direction for some embodiments of this application;

[0066] Figure 7 A cross-sectional view of the main body of an electrode assembly provided in some embodiments of this application, perpendicular to a first direction;

[0067] Figure 8 A front view of the electrode assembly of a battery cell provided in a first direction for other embodiments of this application;

[0068] Figure 9 A front view of the electrode assembly of a battery cell provided in some embodiments of this application in a first direction;

[0069] Figure 10 Exploded views of the battery cell structure provided in some embodiments of this application;

[0070] Figure 11 A cross-sectional view of the main body of an electrode assembly provided in some embodiments of this application, perpendicular to a first direction;

[0071] Figure 12 A front view of the electrode assembly of a battery cell provided in a second direction for some embodiments of this application;

[0072] Figure 13 A front view of the electrode assembly of a battery cell provided in a first direction for some embodiments of this application.

[0073] Icons: 1000 - Vehicle; 100 - Battery assembly; 10 - Housing; 11 - First housing body; 12 - Second housing body; 20 - Battery cell; 21 - Casing; 211 - Housing; 2111 - Opening; 212 - End cap; 22 - Electrode assembly; 221 - Main body; 221a - Electrode segment; 221b - Bending segment; 221c - First stacked region; 221d - Second stacked region; 2211 - Positive electrode sheet; 2211a - First 2211b-First bending segment; 2212-Negative electrode plate; 2212a-Second electrode segment; 2212b-Second bending segment; 2213-Isolator; 222-First electrode tab; 2221-First end; 223-Second electrode tab; 2231-Second end; 23-Electrode terminal; 24-Current collector; 25-Pressure relief component; 200-Controller; 300-Motor; X-First direction; Y-Second direction; Z-Third direction. Detailed Implementation

[0074] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0075] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0076] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0077] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0078] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0079] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0080] In this application, "multiple" means two or more (including two).

[0081] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0082] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0083] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, helps prevent short circuits to some extent while allowing active ions to pass through.

[0084] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0085] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0086] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, as a metal foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0087] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 )), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05At least one of O2 and its modified compounds.

[0088] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0089] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0090] As an example, the negative electrode current collector can be a metal foil, a foamed metal, or a composite current collector. For example, as a metal foil, it can be silver-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0091] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0092] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0093] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as battery negative electrode active materials may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0094] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0095] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0096] In some embodiments, the separator is a separator membrane. The separator membrane can be of various types, and any known porous separator membrane with good chemical and mechanical stability can be selected.

[0097] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0098] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0099] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0100] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0101] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0102] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0103] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0104] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0105] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0106] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0107] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0108] In some implementations, the electrode assembly has a stacked structure.

[0109] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0110] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0111] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0112] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0113] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0114] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0115] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0116] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0117] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include, but are not limited to, square battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries.

[0118] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0119] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0120] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0121] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0122] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0123] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0124] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0125] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0126] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0127] Battery devices possess outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide applicability, and low self-discharge coefficient, making them an important component of today's new energy development. The development of battery technology must simultaneously consider multiple design factors, such as performance parameters like energy density, cycle life, discharge capacity, and charge / discharge rate. Furthermore, the reliability of the battery device must also be taken into account.

[0128] For a typical battery cell, it includes a casing and an electrode assembly housed within the casing. The casing has electrode terminals that are electrically connected to the electrode assembly, allowing the battery cell to input or output electrical energy. In related technologies, to improve the energy density of the battery cell, the electrode assembly is typically configured as a wound or stacked structure. That is, the electrode assembly includes positive and negative electrode plates with opposite polarities, which are formed by winding or stacking. This allows for increasing the volume of the electrode assembly according to actual needs, thereby improving the energy density of the battery cell. One end of each electrode plate is provided with a terminal for connecting to the electrode assembly. The electrode assembly uses interconnected tabs to achieve electrical connection between the electrode assembly and the electrode terminals. However, this type of electrode assembly is prone to problems during use, such as difficulty in electrolyte entering the interior of the electrode assembly, especially the electrodes near the center. This results in poorer electrolyte wetting of the inner electrodes compared to the outer electrodes. Furthermore, the limited electron transport path through the tabs to the inner electrodes increases the risk of lithium plating during use, leading to lower reliability of the battery cell.

[0129] Based on the above considerations, in order to solve the problem of low reliability in the use of battery cells, this application provides a battery cell including a casing and at least one electrode assembly. The electrode assembly is housed within the casing and includes a main body and a plurality of first electrode tabs. The plurality of first electrode tabs are connected to one end of the main body in a first direction and are stacked. The main body includes a plurality of electrode segments stacked along a second direction. The plurality of electrode segments include a plurality of first electrode segments with the same polarity. Each first electrode tab is connected to a first electrode segment, and the first electrode tab has a first end connected to the corresponding first electrode segment. The first direction is perpendicular to the second direction. The main body has a first stacked region and two second stacked regions. The first stacked region is located between the two second stacked regions in the second direction. The difference between the number of first electrode segments in the first stacked region and the sum of the number of first electrode segments in the two second stacked regions is less than or equal to 1, and the number of first electrode segments in the two second stacked regions is the same. In the same cross-section perpendicular to the first direction, the sum of the cross-sectional areas of the first ends of all the first electrode tabs in the first stacked region is greater than the sum of the cross-sectional areas of the first ends of all the first electrode tabs in the two second stacked regions.

[0130] In this battery cell structure, the main body of the electrode assembly is connected to one end in a first direction to a plurality of stacked first tabs, and each first tab is connected to a first electrode segment. The connection positions of the stacked first tabs to the main body are arranged along a second direction. The first stacked region is located between two second stacked regions in the second direction. The difference between the number of first electrode segments in the first stacked region and the sum of the number of first electrode segments in the two second stacked regions is less than or equal to 1, and the number of first electrode segments in the two second stacked regions is the same. The first electrode segment located in the first stacked region is the first electrode segment closest to the center of the electrode assembly among the plurality of first electrode segments stacked along the second direction in the main body. This is achieved by setting the sum of the cross-sectional areas of the first ends of the first tabs on all the first electrode segments in the first stacked region to be greater than the sum of the cross-sectional areas of the first tabs in the two second stacked regions. The sum of the cross-sectional areas of the first ends of the first tabs on all the first electrode segments is such that the sum of the cross-sectional areas of the roots of all the first tabs in the first stacked region is greater than the sum of the cross-sectional areas of the roots of all the first tabs in the two second stacked regions. This makes the area of ​​the first electrode segment near the center of the electrode assembly in the main body that conducts current through the first tab larger than the area of ​​the first electrode segment located on the outer region of the electrode assembly in the main body that conducts current through the first tab. This improves the current path and current demand of the first electrode segment near the center of the electrode assembly in the main body, thereby alleviating the phenomenon of limited electron transport path of the first electrode segment near the center of the electrode assembly through the first tab. In turn, it can effectively reduce the risk of lithium plating caused by poor electrolyte wetting effect of the electrode segments on the inner side of the main body compared with the outer electrode segments, thereby improving the reliability of the battery cell.

[0131] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power system comprising the battery cells and battery devices disclosed in this application can be used to construct such an electrical device. This helps to alleviate the problem of lithium plating in the electrode components of the battery cells during use, thereby improving the reliability of the battery cells.

[0132] This application provides an electrical device that uses a single battery cell or battery assembly as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0133] For ease of explanation, the following embodiments will be described using a vehicle as an example of an electrical device according to an embodiment of this application.

[0134] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000. The battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to supply power to the vehicle 1000; for example, the battery device 100 can serve as the operating power source or general power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 controls the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0135] In some embodiments of this application, the battery device 100 can not only serve as the operating power or power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0136] Please refer to Figure 2 and Figure 3 , Figure 2 This is an exploded view of the structure of the battery device 100 provided in some embodiments of this application. Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application. The battery device 100 includes a housing 10 and battery cells 20, which are housed within the housing 10.

[0137] The housing 10 provides assembly space for the battery cell 20, and can adopt various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which overlap each other, and together define an assembly space for accommodating the battery cell 20. The second housing body 12 may be a hollow structure open at one end, and the first housing body 11 may be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12 so that the first housing body 11 and the second housing body 12 together define the assembly space; alternatively, the first housing body 11 and the second housing body 12 may both be hollow structures open on one side, with the open side of the first housing body 11 covering the open side of the second housing body 12.

[0138] Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder, a cuboid, or a cube. For example, in... Figure 2 In the middle, the shape of box 10 is a cuboid.

[0139] In the battery device 100, there can be one or more battery cells 20 disposed within the housing 10. When there are multiple battery cells 20 disposed within the housing 10, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, in parallel, or in a mixed configuration to form battery modules, and then multiple battery modules are connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10.

[0140] In some embodiments, the battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar for connecting multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20.

[0141] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 20 can be in the form of a cuboid, cylinder, prism, or other shapes. For example, in... Figure 3 In the middle, the battery cell 20 has a cuboid structure.

[0142] According to some embodiments of this application, refer to Figure 3 Please refer to further details. Figure 4 , Figure 5 , Figure 6 and Figure 7 , Figure 4 This is an exploded view of the structure of a battery cell 20 provided in some embodiments of this application. Figure 5 This is a front view of the electrode assembly 22 of the battery cell 20 provided in some embodiments of this application in the second direction Y. Figure 6 This is a front view of the electrode assembly 22 of a battery cell 20 provided in some embodiments of this application in the first direction X. Figure 7This is a cross-sectional view of the main body 221 of the electrode assembly 22 provided in some embodiments of this application, perpendicular to the first direction X. This application provides a battery cell 20, which includes a housing 21 and at least one electrode assembly 22. The electrode assembly 22 is housed within the housing 21 and includes a main body 221 and a plurality of first tabs 222. The plurality of first tabs 222 are connected to one end of the main body 221 in the first direction X and are stacked. The main body 221 includes a plurality of electrode segments 221a stacked along the second direction Y. The plurality of electrode segments 221a include a plurality of first electrode segments 2211a with the same polarity. Each first tab 222 is connected to one first electrode segment 2211a, and the first tab 222 has a first end 2221 connected to the corresponding first electrode segment 2211a. The first direction X is perpendicular to the second direction Y. The main body 221 has a first stacked region 221c and two second stacked regions 221d. The first stacked region 221c is located between the two second stacked regions 221d in the second direction Y. The difference between the number of first pole segments 2211a in the first stacked region 221c and the sum of the number of first pole segments 2211a in the two second stacked regions 221d is less than or equal to 1, and the number of first pole segments 2211a in the two second stacked regions 221d is the same. In the same cross section perpendicular to the first direction X, the sum of the cross-sectional areas of the first ends 2221 of all the first pole tabs 222 in the first stacked region 221c is greater than the sum of the cross-sectional areas of the first ends 2221 of all the first pole tabs 222 in the two second stacked regions 221d.

[0143] The outer shell 21 can also be used to contain electrolytes, such as electrolyte solution. The outer shell 21 can have various structural forms, such as a cylinder, cuboid, or prism. Similarly, the outer shell 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0144] In some embodiments, the housing 21 may include a housing 211 and an end cap 212. The housing 211 has an internal cavity for accommodating the electrode assembly 22 and has an opening 2111. That is, the housing 211 is a hollow structure with an opening 2111 at one end. The end cap 212 covers the opening 2111 of the housing 211 and forms a sealed connection to form a closed space for accommodating the electrode assembly 22 and the electrolyte.

[0145] The housing 211 includes an integrally formed side wall and a bottom wall. The side wall surrounds the bottom wall, one end of the side wall is connected to the bottom wall, and the other end forms an opening 2111. The bottom wall and the end cap 212 are arranged opposite to each other. The side wall and the bottom wall together define a receiving cavity, in which the electrode assembly 22 is received.

[0146] When assembling the battery cell 20, the electrode assembly 22 can be placed into the housing 211 first, and the housing 211 can be filled with electrolyte. Then, the end cap 212 can be closed onto the opening 2111 of the housing 211 to complete the assembly of the battery cell 20.

[0147] The housing 211 can have various shapes, such as a cylinder, cuboid, or prism. The shape of the housing 211 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, a cylindrical housing 211 can be selected; if the electrode assembly 22 is a cuboid structure, a cuboid housing 211 can be selected. Of course, the end cap 212 can also have various structures, such as a plate-like structure or a hollow structure with one end open.

[0148] Of course, it is understandable that the outer casing 21 is not limited to the structure described above. The outer casing 21 can also be other structures. For example, the outer casing 21 can include a housing 211 and two end caps 212. The housing 211 is a hollow structure with openings 2111 on opposite sides. One end cap 212 is fitted onto one opening 2111 of the housing 211 and forms a sealed connection to form a closed space for accommodating the electrode assembly 22 and the electrolyte. That is, the housing 211 has openings 2111 on opposite sides, and the two end caps 212 are fitted onto the opposite sides of the housing 211 to close the corresponding openings 2111.

[0149] In this embodiment, the electrode assembly 22 includes a main body 221, a plurality of first tabs 222 and a plurality of second tabs 223. The main body 221 is the main component of the electrode assembly 22 for chemical reactions to occur inside the battery cell 20. The plurality of first tabs 222 and the plurality of second tabs 223 are connected to the main body 221, and the plurality of first tabs 222 and the plurality of second tabs 223 are spaced apart. The polarities of the first tabs 222 and the second tabs 223 are opposite.

[0150] Optionally, the structure of the electrode assembly 22 can be various. The electrode assembly 22 can be a wound structure formed by winding the positive electrode 2211, the negative electrode 2212 and the separator 2213, or a stacked structure formed by alternately stacking the positive electrode 2211, the negative electrode 2212 and the separator 2213. The separator 2213 is disposed between the positive electrode 2211 and the negative electrode 2212 to separate the positive electrode 2211 and the negative electrode 2212.

[0151] For example, the separator 2213 is a separator membrane, and the main material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0152] The first electrode tabs 222 are connected to one end of the main body 221 in the first direction X and are stacked so that the first electrode tabs 222 form a whole and serve as one input or output electrode of the electrode assembly 22. Correspondingly, the electrode assembly 22 also includes a plurality of second electrode tabs 223. The second electrode tabs 223 are connected to one end of the main body 221 in the first direction X and are stacked so that the second electrode tabs 223 form a whole and serve as another input or output electrode of the electrode assembly 22. This allows the first electrode tabs 222 and the second electrode tabs 223 to cooperate in inputting or outputting electrical energy into or out of the electrode assembly 22.

[0153] For example, in Figure 5 and Figure 6 In this embodiment, the first electrode 222 and the second electrode 223 are both connected to the same end of the main body 221 in the first direction X. Of course, in other embodiments, the first electrode 222 and the second electrode 223 may also be structures that are respectively connected to the two ends of the main body 221 in the first direction X.

[0154] In this embodiment of the application, the positive electrode 2211, negative electrode 2212 and separator 2213 of the electrode assembly 22 are wound or stacked to form the main body 221 of the electrode assembly 22. If the first electrode tab 222 is a positive electrode tab, the first electrode tab 222 is connected to one end of the positive electrode 2211 in the first direction X. Correspondingly, if the second electrode tab 223 is a negative electrode tab, the second electrode tab 223 is connected to one end of the negative electrode 2212 in the first direction X. Conversely, if the first electrode tab 222 is a negative electrode tab, the first electrode tab 222 is connected to one end of the negative electrode 2212 in the first direction X. Correspondingly, if the second electrode tab 223 is a positive electrode tab, the second electrode tab 223 is connected to one end of the positive electrode 2211 in the first direction X.

[0155] The main body 221 includes a plurality of electrode segments 221a stacked along the second direction Y. It should be noted that if the electrode assembly 22 has a wound structure, see [reference needed]. Figure 7 As shown, the multiple electrode segments 221a are multiple flat regions of the positive electrode 2211 and multiple flat regions of the negative electrode 2212. That is to say, the electrode segment 221a is a part of the positive electrode 2211 or a part of the negative electrode 2212.

[0156] The multiple electrode segments 221a include multiple first electrode segments 2211a with the same polarity, that is, the first electrode segment 2211a is the flat region of the positive electrode 2211 or the flat region of the negative electrode 2212. The multiple electrode segments 221a also include multiple second electrode segments 2212a. The second electrode segments 2212a have opposite polarities to the first electrode segments 2211a. If the first electrode segment 2211a is the flat region of the positive electrode 2211, then the second electrode segment 2212a is the flat region of the negative electrode 2212. Conversely, if the first electrode segment 2211a is the flat region of the negative electrode 2212, then the second electrode segment 2212a is the flat region of the positive electrode 2211. Correspondingly, the main body 221 also includes a plurality of bent segments 221b, which include a first bent segment 2211b and a second bent segment 2212b. In the winding direction of the electrode assembly 22, the first bent segment 2211b connects two adjacent first electrode segments 2211a, and the first bent segment 2211b and the first electrode segments 2211a are alternately arranged. Correspondingly, in the winding direction of the electrode assembly 22, the second bent segment 2212b connects two adjacent second electrode segments 2212a, and the second bent segment 2212b and the second electrode segments 2212a are alternately arranged.

[0157] It should be noted that if the electrode assembly 22 is a stacked structure, then the multiple electrode segments 221a are multiple electrodes of the electrode assembly 22. One of the first electrode segment 2211a and the second electrode segment 2212a is a positive electrode 2211 and the other is a negative electrode 2212. The first electrode segment 2211a and the second electrode segment 2212a are arranged in an alternating stacked structure along the first direction X.

[0158] The battery cell 20 includes at least one electrode assembly 22, meaning that the number of electrode assemblies 22 housed within the casing 21 can be one or more. For example, in... Figure 4 In this structure, the electrode assembly 22 has a wound structure. Correspondingly, there can be one or more electrode assemblies 22 housed in the outer casing 21. After the positive electrode 2211 and negative electrode 2212 of the main body portion 221 of each electrode assembly 22 are wound and formed, the tail end of the separator 2213 of the main body portion 221 of each electrode assembly 22 will continue to be wound and correspondingly cover the outside of the positive electrode 2211 and negative electrode 2212 to form the main body portion 221 of a single electrode assembly 22. See [link to relevant documentation]. Figure 4As shown, two electrode assemblies 22 are disposed within the casing 21 of the battery cell 20. The two electrode assemblies 22 are stacked along their thickness direction. Of course, in other embodiments, the electrode assemblies 22 housed within the casing 21 can be three, four, five, six, seven, or eight, etc. It should be noted that in this embodiment, the length direction of the electrode assembly 22 is the first direction X, the thickness direction of the electrode assembly 22 is the second direction Y, and the width direction of the electrode assembly 22 is the third direction Z. It should also be noted that if the electrode assembly 22 has a stacked structure, the number of electrode assemblies 22 housed within the casing 21 is usually one.

[0159] For example, in Figure 7 In this embodiment, the electrode assembly 22 has a wound structure. The first electrode segment 2211a is the flat region of the positive electrode 2211, and the positive electrode 2211 also includes a first bent segment 2211b. Correspondingly, the second electrode segment 2212a is the flat region of the negative electrode 2212, and the negative electrode 2212 also includes a second bent segment 2212b. Of course, in other embodiments, the first electrode segment 2211a can also be the flat region of the negative electrode 2212, and the negative electrode 2212 can also include a first bent segment 2211b. Correspondingly, the second electrode segment 2212a is the flat region of the positive electrode 2211, and the positive electrode 2211 also includes a second bent segment 2212b.

[0160] The first electrode segment 2211a includes a first current collector and a first active material layer disposed on at least one side of the first current collector. The first electrode tab 222 is connected to one end of the first current collector in the first direction X of the first electrode segment 2211a. Optionally, the first electrode tab 222 and the first current collector can be integrally formed or separately disposed. If the first electrode tab 222 and the first current collector are integrally formed, then the first electrode tab 222 and the first current collector are formed by cutting the same metal foil. If the first electrode tab 222 and the first current collector are separately disposed, then the first electrode tab 222 can be connected to the first current collector by welding or other structures. Similarly, the second electrode segment 2212a includes a second current collector and a second active material layer disposed on at least one side of the second current collector. The second electrode tab 223 is connected to one end of the second current collector in the first direction X of the second electrode segment 2212a. Optionally, the second electrode tab 223 and the second current collector can be integrally formed or separately disposed. If the second electrode tab 223 and the second current collector are integrally formed, then the second electrode tab 223 and the second current collector are formed by cutting the same metal foil. If the second electrode tab 223 and the second current collector are separately disposed, then the second electrode tab 223 can be connected to the second current collector by welding or other structures.

[0161] Each first electrode tab 222 is connected to a first electrode segment 2211a, that is, the multiple first electrode tabs 222 are arranged along the second direction Y. In other words, the connection position of the multiple first electrode tabs 222 to the main body 221 is arranged along the second direction Y.

[0162] The first electrode tab 222 has a first end 2221 connected to the corresponding first electrode segment 2211a. That is, the first end 2221 is the root of the first electrode tab 222 connected to the corresponding first electrode segment 2211a. Correspondingly, the first end 2221 is also the root of the first electrode tab 222.

[0163] Multiple first electrodes 222 are stacked, that is, multiple first electrodes 222 are stacked together along their thickness direction to form an integral structure. It should be noted that multiple first electrodes 222 can form a connection structure, such as welding connection, that is, multiple first electrodes 222 are stacked and welded together. Of course, multiple first electrodes 222 can also be a structure that is only stacked together and the multiple first electrodes 222 are not connected to each other.

[0164] In this embodiment, the main body 221 has a first stacked region 221c and two second stacked regions 221d. The first stacked region 221c is located between the two second stacked regions 221d in the second direction Y. That is, see [link to previous embodiment]. Figure 6 As shown, the main body 221 is divided into three regions along the second direction Y by a plurality of pole segments 221a stacked in the second direction Y: a first stacked region 221c located at the center and two second stacked regions 221d located on both sides of the first stacked region 221c.

[0165] The difference between the number of first pole pieces 2211a in the first stacked region 221c and the sum of the number of first pole pieces 2211a in the two second stacked regions 221d is less than or equal to 1, and the number of first pole pieces 2211a in the two second stacked regions 221d is the same. That is, in the second direction Y, the number of first pole pieces 2211a on one side of the first stacked region 221c is the same as the number of first pole pieces 2211a on the other side of the first stacked region 221c, and the sum of the number of first pole pieces 2211a on both sides of the first stacked region 221c is equal to the number of first pole pieces in the first stacked region 221c. The number of segments 2211a is either equal or the difference is equal to 1. That is, the sum of the number of first pole segments 2211a on both sides of the first stacked region 221c is equal to the number of first pole segments 2211a within the first stacked region 221c. Alternatively, the sum of the number of first pole segments 2211a on both sides of the first stacked region 221c is one more than the number of first pole segments 2211a within the first stacked region 221c. Or, the sum of the number of first pole segments 2211a on both sides of the first stacked region 221c is one less than the number of first pole segments 2211a within the first stacked region 221c.

[0166] Within the same cross-section perpendicular to the first direction X, the sum of the cross-sectional areas of the first ends 2221 of all the first tabs 222 within the first stacked region 221c is greater than the sum of the cross-sectional areas of the first ends 2221 of all the first tabs 222 within the two second stacked regions 221d. That is, within the same cross-section, and this cross-section is a plane perpendicular to the first direction X, the roots of the first tabs 222 on all the first pole segments 2211a within the first stacked region 221c have cross-sections perpendicular to the first direction X. The sum of the areas is greater than the sum of the areas of the cross sections of the roots of the first pole pieces 221a on all the first pole pieces 221a located in the two second stacked regions 221d perpendicular to the first direction X. Correspondingly, the total flow area between the multiple first pole pieces 221a located in the first stacked region 221c and the corresponding multiple first pole pieces 222 is greater than the total flow area between the multiple first pole pieces 221a located in the two second stacked regions 221d and the corresponding multiple first pole pieces 222.

[0167] In some embodiments, see Figure 3 and Figure 4 As shown, the battery cell 20 may also include an electrode terminal 23, which is insulated and mounted on the housing 21. The electrode terminal 23 is used to electrically connect with the electrode assembly 22 to output or input electrical energy of the battery cell 20.

[0168] It should be noted that the electrode terminal 23 is insulated and mounted on the housing 21, meaning that there is no electrical connection between the electrode terminal 23 and the housing 21.

[0169] Among them, Figure 3 and Figure 4 In the battery cell 20, there are two electrode terminals 23. The two electrode terminals 23 are spaced apart on the end cap 212 of the housing 21. The two electrode terminals 23 are electrically connected to the first tab 222 and the second tab 223 of the electrode assembly 22, respectively, so as to realize the input or output of electrical energy of the battery cell 20.

[0170] For example, the electrode terminal 23 can be made of various materials, such as copper, iron, aluminum, steel or aluminum alloy.

[0171] Optionally, the structure in which the electrode terminal 23 is mounted on the housing 21 can be varied; for example, in Figure 3 and Figure 4 In this embodiment, both electrode terminals 23 are mounted on the end cap 212 of the housing 21. Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the battery cell 20 can also have other structures. For example, both electrode terminals 23 can be mounted on the housing 211 of the housing 21. Similarly, one electrode terminal 23 can be mounted on the housing 211 of the housing 21, and the other electrode terminal 23 can be mounted on the end cap 212 of the housing 21.

[0172] In some embodiments, see Figure 4 As shown, the battery cell 20 may also include two current collectors 24. Both current collectors 24 are disposed inside the housing 21 and are spaced apart. One current collector 24 is used to connect one electrode terminal 23 and the first tab 222 of multiple electrode assemblies 22, and the other current collector 24 is used to connect another electrode terminal 23 and the second tab 223 of multiple electrode assemblies 22, so as to realize the electrical connection between the two electrode terminals 23 and the electrode assemblies 22, which helps to reduce the assembly difficulty between the electrode assemblies 22 and the electrode terminals 23.

[0173] For example, the material of the current collector 24 can be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0174] In some embodiments, see Figure 3 and Figure 4 As shown, the battery cell 20 may also include a pressure relief component 25, which is disposed on the housing 21. The pressure relief component 25 is used to release the internal pressure of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0175] Optionally, the pressure relief component 25 may be disposed on the end cap 212 of the housing 21 or on the housing 211 of the housing 21. For example, the pressure relief component 25 is disposed on the end cap 212 of the housing 21.

[0176] Optionally, the pressure relief component 25 and the outer casing 21 can be an integrally formed structure or a separate structure. If the pressure relief component 25 and the outer casing 21 are separate structures, the pressure relief component 25 can be connected to the outer casing 21 by welding or other means. Correspondingly, the pressure relief component 25 can be a component such as an explosion-proof valve, explosion-proof disc, gas valve, pressure relief valve, or safety valve. If the pressure relief component 25 and the outer casing 21 are an integrally formed structure, the pressure relief component 25 is an area on the outer casing 21 with a weak structure, such as an area on the outer casing 21 with a groove.

[0177] In this embodiment, the main body 221 of the electrode assembly 22 is connected to one end in the first direction X with a plurality of stacked first electrode tabs 222, and each first electrode tab 222 is connected to a first electrode segment 2211a, such that the connection positions of the stacked first electrode tabs 222 and the main body 221 are arranged along the second direction Y. The first stacked region 221c is located between two second stacked regions 221d in the second direction Y. The number of first electrode segments 2211a in the first stacked region 221c is equal to the number of first electrode sheets in the two second stacked regions 221d. The difference in the sum of the number of segments 2211a is less than or equal to 1, and the number of first electrode segments 2211a in the two second stacked regions 221d is the same, so that the first electrode segments 2211a located in the first stacked region 221c are the first electrode segments 2211a near the center position of the electrode assembly 22 among the multiple first electrode segments 2211a stacked along the second direction Y of the main body 221. This is achieved by setting the sum of the cross-sectional areas of the first ends 2221 of the first electrode tabs 222 on all the first electrode segments 2211a in the first stacked region 221c to be greater than ... the two second stacked regions 221d. The sum of the cross-sectional areas of the first ends 2221 of the first tabs 222 on all the first electrode segments 2211a in the stack region 221d is such that the sum of the cross-sectional areas of the roots of all the first tabs 222 in the first stack region 221c is greater than the sum of the cross-sectional areas of the roots of all the first tabs 222 in the two second stack regions 221d, so that the area of ​​the first electrode segment 2211a near the center of the electrode assembly 22 in the main body 221 that conducts current through the first tab 222 is greater than the area of ​​the first electrode segment 2211a located on the outer side of the electrode assembly 22 in the main body 221. The larger area of ​​the first electrode segment 221a conducting current through the first tab 222 improves the current path and current demand of the first electrode segment 2211a near the center of the main body 221 of the electrode assembly 22, thereby alleviating the phenomenon of limited electron transmission path of the first electrode segment 2211a near the center of the electrode assembly 22 through the first tab 222. This effectively reduces the risk of lithium plating caused by poor electrolyte wetting effect of the electrode segment 221a on the inner side of the main body 221 compared to the outer electrode segment 221a, thus improving the reliability of the battery cell 20.

[0178] According to some embodiments of this application, in conjunction with Figure 4 , Figure 5 , Figure 6 and Figure 7As shown, the electrode assembly 22 has a wound structure, and the winding center axis of the electrode assembly 22 extends along the first direction X. The main body 221 also includes a plurality of bent segments 221b, including a first bent segment 2211b. Along the winding direction of the electrode assembly 22, the first bent segment 2211b connects two adjacent first electrode segments 2211a, and the first bent segment 2211b and the first electrode segments 2211a are alternately arranged.

[0179] In this embodiment, the multiple pole segments 221a of the main body 221 are connected to multiple bent segments 221b at both ends in the third direction Z. In the wound electrode assembly 22, the pole segments 221a are the straight areas of the positive electrode 2211 and the negative electrode 2212 of the electrode assembly 22, while the bent segments 221b are the bent areas of the positive electrode 2211 and the negative electrode 2212 of the electrode assembly 22. Correspondingly, the multiple bent segments 221b also include second bent segments 2212b. Along the winding direction of the electrode assembly 22, the second bent segments 2212b connect two adjacent second pole segments 2212a, and the second bent segments 2212b and the second pole segments 2212a are alternately arranged.

[0180] Along the winding direction of the electrode assembly 22, the first bent segment 2211b connects two adjacent first pole segments 2211a, and the first bent segment 2211b and the first pole segment 2211a are alternately arranged. That is, in the winding direction of the electrode assembly 22, the first bent segment 2211b and the first pole segment 2211a are arranged alternately and connected, so that both ends of the first pole segment 2211a in the third direction Z are connected to the first bent segment 2211b. Similarly, in the winding direction of the electrode assembly 22, the second bent segment 2212b and the second pole segment 2212a are also arranged alternately and connected, so that both ends of the second pole segment 2212a in the third direction Z are connected to the second bent segment 2212b.

[0181] It should be noted that the structure formed by the alternating arrangement and connection of multiple first electrode segments 2211a and multiple first bending segments 2211b is one of the positive electrode 2211 and negative electrode 2212 of the electrode assembly 22, and the structure formed by the alternating arrangement and connection of multiple second electrode segments 2212a and multiple second bending segments 2212b is the other of the positive electrode 2211 and negative electrode 2212 of the electrode assembly 22.

[0182] In this embodiment, by setting the electrode assembly 22 as a wound structure, a first electrode segment 2211a is formed between two adjacent first bending segments 2211b in the winding direction of the electrode assembly 22. The electrode assembly 22 with this structure is beneficial to improving the energy density of the battery cell 20.

[0183] According to some embodiments of this application, see Figure 6 As shown, the first pole segment 2211a in the first stacked region 221c and the first pole segment 2211a in the two second stacked regions 221d are all connected to the first pole tab 222. That is, each of the multiple first pole segments 2211a arranged along the second direction Y in the main body 221 is connected to the first pole tab 222.

[0184] In this embodiment, by connecting the first electrode segments 2211a located in the first stacked region 221c and the two second stacked regions 221d to the first tabs 222, the first electrode segments 2211a on both sides of the main body 221 located at the center of the electrode assembly 22 in the second direction Y are connected to the first tabs 222. This improves the overall current requirements and current path of the electrode assembly 22, thereby further reducing the risk of lithium plating during the use of the electrode assembly 22.

[0185] According to some embodiments of this application, refer to Figure 8 As shown, Figure 8 This is a front view of the electrode assembly 22 of the battery cell 20 provided in some other embodiments of this application in the first direction X. Along the second direction Y, each of the first electrode segments 2211a located on one side of the center position of the electrode assembly 22 is connected to a first tab 222. That is, the main body 221 has a structure in which a first tab 222 is provided on each of the multiple first electrode segments 2211a on one side of the electrode assembly 22 at the center position of the electrode assembly 22.

[0186] In this embodiment, by connecting the first electrode segment 2211a located on one side of the center position of the electrode assembly 22 in the second direction Y to the first electrode tab 222, the electrode assembly 22 is a structure with multiple first electrode tabs 222 on one side in the second direction Y. This reduces the difficulty of setting multiple stacked first electrode tabs 222 at one end of the main body 221, thereby reducing the manufacturing difficulty of the electrode assembly 22.

[0187] According to some embodiments of this application, see Figure 6 as well as Figure 8As shown, in two adjacent first tabs 222, within the same cross-section perpendicular to the first direction X, along the second direction Y, the cross-sectional area of ​​the first end 2221 of the first tab 222 closer to the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 farther from the center of the electrode assembly 22. That is, among the multiple first tabs 222 arranged along the second direction Y, and within the same cross-section perpendicular to the first direction X, the cross-sectional area of ​​the root of the first tab 222 closer to the center of the electrode assembly 22 is larger, such that the cross-sectional area of ​​the root of the multiple first tabs 222 gradually decreases from the center of the electrode assembly 22 towards at least one side. Correspondingly, the flow area between the multiple first tabs 222 and the corresponding first electrode segment 2211a also gradually decreases from the center of the electrode assembly 22 towards at least one side.

[0188] In this embodiment, by setting the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 among the multiple first tabs 222 stacked in the second direction Y to be greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 far from the center of the electrode assembly 22, the cross-sectional area of ​​the first end 2221 of the first tab 222 on the first electrode segment 2211a inside the electrode assembly 22 gradually decreases from the first tab 222 on the first electrode segment 2211a outside the electrode assembly 22. This achieves a structure in which the sum of the cross-sectional areas of the first end 2221 of the first tabs 222 on all the first electrode segments 2211a in the first stacked region 221c is greater than the sum of the cross-sectional areas of the first end 2221 of the first tabs 222 on all the first electrode segments 2211a in the two second stacked regions 221d, which helps to reduce the manufacturing difficulty of the electrode assembly 22.

[0189] According to some embodiments of this application, see Figure 5 and Figure 6 as well as Figure 8 As shown, in two adjacent first tabs 222, in the same cross section perpendicular to the first direction X, the width of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the third direction Z is greater than the width of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the third direction Z. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0190] Wherein, the cross-section is a plane perpendicular to the first direction X, and the width of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the third direction Z is greater than the width of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the third direction Z. That is to say, the width of the root of the first tab 222 in the third direction Z is a structure that gradually decreases from the center of the electrode assembly 22 in the second direction Y to at least one side.

[0191] In this embodiment, among two adjacent first tabs 222, by setting the width of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the third direction Z to be greater than the width of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the third direction Z, the width of the first end 2221 of the first tab 222 on the third direction gradually decreases from the first tab 222 on the inner side of the first electrode segment 2211a to the first tab 222 on the outer side of the first electrode segment 2211a. This achieves a structure in which the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 away from the center of the electrode assembly 22. The structure is simple and easy to manufacture.

[0192] In some embodiments, please continue to see Figure 5 and Figure 6 as well as Figure 8 As shown, in the same cross section perpendicular to the first direction X, the first ends 2221 of the plurality of first tabs 222 have the same thickness in the second direction Y.

[0193] Of course, in other embodiments, the thickness of the first ends 2221 of the plurality of first tabs 222 in the second direction Y can also be different in the same cross section perpendicular to the first direction X.

[0194] In this embodiment, by setting the thickness of the first ends 2221 of the multiple first tabs 222 in the second direction Y to be the same, on the one hand, the molding difficulty of the multiple first tabs 222 can be reduced, which is beneficial to reducing the manufacturing difficulty of the electrode assembly 22. On the other hand, it is convenient to set the first tabs 222 with different cross-sectional areas by adjusting the width of the first ends 2221 of the first tabs 222 in the third direction Z, which is beneficial to improving the processing accuracy of the cross-sectional area of ​​the first ends 2221 of the multiple first tabs 222.

[0195] In some embodiments, see Figure 6 as well as Figure 8As shown, in two adjacent first tabs 222, the first tab 222 closer to the center of the electrode assembly 22 extends along the third direction Z beyond the two ends of the first tab 222 farther from the center of the electrode assembly 22 in the third direction Z.

[0196] In this embodiment, by setting the first tab 222 near the center of the electrode assembly 22 to extend beyond the two ends of the first tab 222 far from the center of the electrode assembly 22 in the third direction Z, it is convenient to stack multiple first tabs 222 on each other, which helps to reduce the processing difficulty of the electrode assembly 22 and improve the processing quality of the electrode assembly 22. On the other hand, it can alleviate the misalignment between two adjacent first tabs 222, thereby reducing the total misalignment of multiple first tabs 222 in the third direction Z. This can reduce the risk of short circuit caused by the large misalignment of multiple first tabs 222 in the third direction Z, thereby improving the reliability of the battery cell 20.

[0197] Of course, in embodiments where the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 along the second direction Y is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 away from the center of the electrode assembly 22, the electrode assembly 22 may also have other structures. For example, in two adjacent first tabs 222, in the same cross-section perpendicular to the first direction X, the thickness of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the second direction Y is greater than the thickness of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the second direction Y.

[0198] It should be noted that in embodiments where the thickness of the first end 2221 of the first tab 222 is different, the width of the first end 2221 of the multiple first tabs 222 in the third direction Z can be the same structure or different structures.

[0199] In this embodiment, in two adjacent first tabs 222, the thickness of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the second direction Y is set to be greater than the thickness of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the second direction Y. This results in a structure where the thickness of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 is gradually decreasing from the first tab 222 on the inner side of the first electrode segment 2211a to the first tab 222 on the outer side of the first electrode segment 2211a. This achieves a structure where the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 away from the center of the electrode assembly 22. This structure is simple and easy to manufacture.

[0200] In an embodiment where the thickness of the first end 2221 of the first tab 222 located near the center of the electrode assembly 22 in the second direction Y is greater than the thickness of the first end 2221 of the first tab 222 located away from the center of the electrode assembly 22 in the second direction Y, in the same cross section perpendicular to the first direction X, the first ends 2221 of the plurality of first tabs 222 have the same width in the third direction Z, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0201] In this embodiment, by setting the width of the first ends 2221 of the multiple first tabs 222 in the third direction Z to be the same, it is possible to achieve a structure in which the cross-sectional area of ​​the first ends 2221 of the first tabs 222 near the center of the electrode assembly 22 is greater than that of the first ends 2221 of the first tabs 222 far from the center of the electrode assembly 22, while also achieving a structure in which the multiple first tabs 222 have equal widths in the third direction Z. On the one hand, multiple first tabs 222 can be formed by cutting the edge once, which is beneficial to improving the processing efficiency of multiple first tabs 222. On the other hand, it can improve the regularity of the multiple first tabs 222 stacked together.

[0202] Of course, the structure of the electrode assembly 22 is not limited to this. In some embodiments, the electrode assembly 22 can also have other structures, for example, referring to Figure 9 , Figure 9 This is a front view of the electrode assembly 22 of a battery cell 20 provided in some embodiments of this application in the first direction X. Each first electrode segment 2211a in the first stacked region 221c is connected to a first electrode tab 222, and only one of the two second stacked regions 221d has first electrode segments 2211a connected to first electrode tabs 222. In the same cross-section perpendicular to the first direction X, the first ends 2221 of the plurality of first electrode tabs 222 have the same thickness in the second direction Y, and the first ends 2221 of the plurality of first electrode tabs 222 have the same width in the third direction Z. In other words, the roots of the multiple first tabs 222 connected to the main body 221 of the electrode assembly 22 are all structures with the same width and thickness. Correspondingly, the multiple first electrode segments 2211a located in the first stacked region 221c are all connected to the first tabs 222, but the first electrode segments 2211a located on both sides of the first stacked region 221c are only connected to the first tabs 222 on one side.

[0203] In this embodiment, by providing first tabs 222 on all first electrode segments 2211a within the first stacked region 221c, and only providing first tabs 222 on the first electrode segments 2211a within one of the two second stacked regions 221d, the main body 221 has a structure where multiple first electrode segments 2211a near the center of the electrode assembly 22 are connected to first tabs 222, while the outer region of the electrode assembly 22 has a structure where only one side of the first electrode segments 2211a is connected to the first tabs 222. This results in the number of first tabs 222 on the main body 221 near the center of the electrode assembly 22 being greater than the number of first tabs 222 on the outer region of the electrode assembly 22. The number of first tabs 222 in the outer region of the component 22 is reduced so that the sum of the cross-sectional areas of the first ends 2221 of the first tabs 222 on the first electrode segment 221a in the first stacking region 221c is greater than the sum of the cross-sectional areas of the first ends 2221 of the first tabs 222 on the first electrode segment 2211a in the two second stacking regions 221d. This facilitates the forming of multiple first tabs 222 and reduces the stacking difficulty of multiple first tabs 222, thereby reducing the manufacturing difficulty of the electrode component 22.

[0204] According to some embodiments of this application, refer to Figure 10 , Figure 11 , Figure 12 and Figure 13 , Figure 10 This is an exploded view of the structure of a battery cell 20 provided in some embodiments of this application. Figure 11 A cross-sectional view of the main body 221 of the electrode assembly 22 provided in some embodiments of this application, perpendicular to the first direction X. Figure 12 This is a front view of the electrode assembly 22 of the battery cell 20 provided in some embodiments of this application in the second direction Y. Figure 13This is a front view of the electrode assembly 22 of a battery cell 20 provided in some embodiments of this application in the first direction X. The electrode assembly 22 has a stacked structure, and the multiple electrode segments 221a further include multiple second electrode segments 2212a of the same polarity. The second electrode segments 2212a and the first electrode segments 2211a are stacked and alternately arranged along the second direction Y. One of the first electrode segments 2211a and the second electrode segments 2212a is a positive electrode 2211 and the other is a negative electrode 2212. Each first electrode segment 2211a is connected to a first tab 222. In two adjacent first tabs 222, in the same cross-section perpendicular to the first direction X, along the second direction Y, the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 away from the center of the electrode assembly 22.

[0205] In the embodiment where the electrode assembly 22 has a stacked structure, the main body 221 does not have a bent section 221b. The main body 221 of the electrode assembly 22 includes positive electrode 2211 and negative electrode 2212 alternately stacked along the second direction Y, and a spacer 2213 is provided between each adjacent positive electrode 2211 and negative electrode 2212. Correspondingly, the multiple electrode segments 221a of the main body 221 are the positive electrode 2211 and negative electrode 2212 of the main body 221.

[0206] For example, in Figure 11 In the first electrode segment 2211a, the positive electrode 2211 is formed, and the second electrode segment 2212a, the negative electrode 2212 is formed.

[0207] Each first pole segment 2211a is connected to a first pole tab 222, that is, each first pole segment 2211a in the multiple pole segments 221a of the main body 221 is connected to a first pole tab 222.

[0208] In two adjacent first tabs 222, within the same cross-section perpendicular to the first direction X, along the second direction Y, the cross-sectional area of ​​the first end 2221 of the first tab 222 closer to the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 farther from the center of the electrode assembly 22. That is, among the multiple first tabs 222 arranged along the second direction Y, and within the same cross-section perpendicular to the first direction X, the cross-sectional area of ​​the root of the first tab 222 closer to the center of the electrode assembly 22 is larger, so that the cross-section of the root of the multiple first tabs 222 connected to the corresponding first electrode segment 2211a has a structure that gradually decreases from the center of the electrode assembly 22 towards at least one side. Correspondingly, the flow area between the multiple first tabs 222 and the corresponding first electrode segment 2211a has a structure that gradually decreases from the center of the electrode assembly 22 towards at least one side.

[0209] In this embodiment, by setting the electrode assembly 22 as a stacked structure, the positive electrode 2211 and negative electrode 2212 stacked along the second direction Y of the electrode assembly 22 are multiple electrode segments 221a of the electrode assembly 22. The electrode assembly 22 with this structure can increase the thickness of the electrode assembly 22 in the second direction Y according to actual needs to meet different usage requirements. Furthermore, each first electrode segment 2211a in the main body 221 of the stacked electrode assembly 22 is connected to a first electrode tab 222. By setting the cross-sectional area of ​​the first end 2221 of the first electrode tab 222 near the center of the electrode assembly 22 to be greater than the cross-sectional area of ​​the first end 2221 of the first electrode tab 222 far from the center of the electrode assembly 22, the cross-sectional area of ​​the first end 2221 of the first electrode tab 222 on the first electrode segment 2211a on the inner side of the electrode assembly 22 gradually decreases from the first electrode tab 222 on the first electrode segment 2211a on the outer side. This achieves a structure in which the sum of the cross-sectional areas of the first end 2221 of the first electrode tab 222 on the first electrode segment 2211a in the first stacked region 221c is greater than the sum of the cross-sectional areas of the first end 2221 of the first electrode tab 222 on the first electrode segment 2211a in the two second stacked regions 221d, which helps to reduce the manufacturing difficulty of the electrode assembly 22.

[0210] According to some embodiments of this application, see Figure 12 and Figure 13 As shown, in two adjacent first tabs 222, in the same cross section perpendicular to the first direction X, the width of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the third direction Z is greater than the width of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the third direction Z. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0211] Wherein, the cross-section is a plane perpendicular to the first direction X. The width of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the third direction Z is greater than the width of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the third direction Z. That is to say, the width of the root of the first tab 222 connected to the first electrode segment 2211a in the third direction Z is a structure that gradually decreases from the center of the electrode assembly 22 in the second direction Y to both sides.

[0212] In this embodiment, among two adjacent first tabs 222, by setting the width of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the third direction Z to be greater than the width of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the third direction Z, the width of the first end 2221 of the first tab 222 on the third direction gradually decreases from the first tab 222 on the inner side of the first electrode segment 2211a to the first tab 222 on the outer side of the first electrode segment 2211a. This achieves a structure in which the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 away from the center of the electrode assembly 22. The structure is simple and easy to manufacture.

[0213] In some embodiments, please continue to see Figure 12 and Figure 13 As shown, in the same cross section perpendicular to the first direction X, the first ends 2221 of the plurality of first tabs 222 have the same thickness in the second direction Y.

[0214] Of course, in other embodiments, the thickness of the first ends 2221 of the plurality of first tabs 222 in the second direction Y can also be different in the same cross section perpendicular to the first direction X.

[0215] In this embodiment, by setting the thickness of the first ends 2221 of the multiple first tabs 222 in the second direction Y to be the same, on the one hand, the molding difficulty of the multiple first tabs 222 can be reduced, which is beneficial to reducing the manufacturing difficulty of the electrode assembly 22. On the other hand, it is convenient to set the first tabs 222 with different cross-sectional areas by adjusting the width of the first ends 2221 of the first tabs 222 in the third direction Z, which is beneficial to improving the processing accuracy of the cross-sectional area of ​​the first ends 2221 of the multiple first tabs 222.

[0216] In some embodiments, see Figure 12 and Figure 13As shown, in two adjacent first tabs 222, the first tab 222 closer to the center of the electrode assembly 22 extends along the third direction Z beyond the two ends of the first tab 222 farther from the center of the electrode assembly 22 in the third direction Z.

[0217] In this embodiment, by setting the first tab 222 near the center of the electrode assembly 22 to extend beyond the two ends of the first tab 222 far from the center of the electrode assembly 22 in the third direction Z, it is convenient to stack multiple first tabs 222 on each other, which helps to reduce the processing difficulty of the electrode assembly 22 and improve the processing quality of the electrode assembly 22. On the other hand, it can alleviate the misalignment between two adjacent first tabs 222, thereby reducing the total misalignment of multiple first tabs 222 in the third direction Z. This can reduce the risk of short circuit caused by the large misalignment of multiple first tabs 222 in the third direction Z, thereby improving the reliability of the battery cell 20.

[0218] Of course, in embodiments where the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 along the second direction Y is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 away from the center of the electrode assembly 22, the electrode assembly 22 may also have other structures. For example, in two adjacent first tabs 222, in the same cross-section perpendicular to the first direction X, the thickness of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the second direction Y is greater than the thickness of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the second direction Y.

[0219] It should be noted that in embodiments where the thickness of the first end 2221 of the first tab 222 in the second direction Y is different, the width of the first end 2221 of the multiple first tabs 222 in the third direction Z can be the same structure or different structures.

[0220] In this embodiment, in two adjacent first tabs 222, the thickness of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 in the second direction Y is set to be greater than the thickness of the first end 2221 of the first tab 222 away from the center of the electrode assembly 22 in the second direction Y. This results in a structure where the thickness of the first end 2221 of the first tab 222 near the center of the electrode assembly 22 is gradually decreasing from the first tab 222 on the inner side of the first electrode segment 2211a to the first tab 222 on the outer side of the first electrode segment 2211a. This achieves a structure where the cross-sectional area of ​​the first end 2221 of the first tab 222 near the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the first end 2221 of the first tab 222 away from the center of the electrode assembly 22. This structure is simple and easy to manufacture.

[0221] In an embodiment where the thickness of the first end 2221 of the first tab 222 located near the center of the electrode assembly 22 in the second direction Y is greater than the thickness of the first end 2221 of the first tab 222 located away from the center of the electrode assembly 22 in the second direction Y, in the same cross section perpendicular to the first direction X, the first ends 2221 of the plurality of first tabs 222 have the same width in the third direction Z, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0222] In this embodiment, by setting the width of the first ends 2221 of the multiple first tabs 222 in the third direction Z to be the same, it is possible to achieve a structure in which the cross-sectional area of ​​the first ends 2221 of the first tabs 222 near the center of the electrode assembly 22 is greater than that of the first ends 2221 of the first tabs 222 far from the center of the electrode assembly 22, while also achieving a structure in which the multiple first tabs 222 have equal widths in the third direction Z. On the one hand, multiple first tabs 222 can be formed by cutting the edge once, which is beneficial to improving the processing efficiency of multiple first tabs 222. On the other hand, it can improve the regularity of the multiple first tabs 222 stacked together.

[0223] According to some embodiments of this application, the first electrode segment 2211a includes a first current collector and a first active material layer disposed on at least one side of the first current collector, and the first electrode tab 222 is connected to one end of the first current collector in the first direction X, and the first electrode tab 222 is integrally formed with the first current collector.

[0224] The second electrode segment 2212a includes a second current collector and a second active material layer disposed on at least one side of the second current collector, and the second electrode tab 223 is connected to one end of the second current collector in the first direction X.

[0225] If the first electrode segment 2211a is the positive electrode 2211 or a part of the positive electrode 2211 of the electrode assembly 22, then the first active material layer of the first electrode segment 2211a includes positive active material, and the first electrode tab 222 is the positive electrode tab of the electrode assembly 22. Correspondingly, the second electrode segment 2212a is the negative electrode 2212 or a part of the negative electrode 2212 of the electrode assembly 22, the second active material layer of the second electrode segment 2212a includes negative active material, and the second electrode tab 223 is the negative electrode tab of the electrode assembly 22; otherwise... If the first electrode segment 2211a is a negative electrode 2212 or a part of the negative electrode 2212 of the electrode assembly 22, then the first active material layer of the first electrode segment 2211a includes a negative active material, and the first electrode tab 222 is a negative electrode tab of the electrode assembly 22. Correspondingly, if the second electrode segment 2212a is a positive electrode 2211 or a part of the positive electrode 2211 of the electrode assembly 22, then the second active material layer of the second electrode segment 2212a includes a positive active material, and the second electrode tab 223 is a positive electrode tab of the electrode assembly 22.

[0226] The first electrode 222 and the first current collector are integrally formed, that is, the first electrode 222 and the first current collector are formed by cutting the same metal foil. Correspondingly, the first end 2221 is the end that connects the first electrode 222 and the first current collector. Similarly, the second electrode 223 and the second current collector are also integrally formed, that is, the second electrode 223 and the second current collector are formed by cutting the same metal foil.

[0227] In this embodiment, by setting the first tab 222 and the first current collector as an integrally formed structure, the first tab 222 and the first current collector are made of the same foil material through an integral forming process, which helps to improve the connection stability and reliability between the first tab 222 and the first current collector, thereby reducing the risk of connection failure between the first tab 222 and the first current collector.

[0228] Of course, in other embodiments, the electrode assembly 22 may also have other structures, such as the first electrode tab 222 and the first current collector being separately configured.

[0229] The first electrode 222 and the first current collector can be connected by a structure such as welding.

[0230] In this embodiment, by setting the first tab 222 and the first current collector as separate components, the size of the first tab 222 is not constrained by the first current collector, thereby enabling the first tab 222 of different sizes to be set according to actual needs, which is beneficial to improving the production flexibility of the electrode assembly 22.

[0231] According to some embodiments of this application, see Figure 4 and Figure 5 as well as Figure 10 and Figure 12 As shown, the positive electrode active material of electrode assembly 22 includes lithium transition metal oxide, and the length of the main body 221 in the first direction X is L, satisfying 100mm≤L≤200mm. Alternatively, the positive electrode active material of electrode assembly 22 includes lithium phosphate, and the length of the main body 221 in the first direction X is L, satisfying 200mm≤L≤350mm.

[0232] The positive active material of the electrode assembly 22 is the material in the positive active material layer on the positive electrode sheet 2211. If the first electrode segment 2211a is the positive electrode sheet 2211 or a part of the positive electrode sheet 2211 of the electrode assembly 22, then the first active material layer of the first electrode segment 2211a includes the positive active material. Of course, if the second electrode segment 2212a is the positive electrode sheet 2211 or a part of the positive electrode sheet 2211 of the electrode assembly 22, then the second active material layer of the second electrode segment 2212a includes the positive active material.

[0233] The positive electrode active material of the electrode assembly 22 includes lithium transition metal oxide, and the length of the main body 221 in the first direction X is 100mm-200mm. That is, the positive electrode active material layer of the positive electrode sheet 2211 of the electrode assembly 22 includes at least one of lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide and their modified compounds. Then the length of the main body 221 of the electrode assembly 22 in the first direction X is L, which satisfies 100mm≤L≤200mm.

[0234] For example, in an embodiment where the positive electrode active material of the electrode assembly 22 includes lithium transition metal oxide, the length L of the main body portion 221 of the electrode assembly 22 in the first direction X can be 100mm, 105mm, 110mm, 115mm, 120mm, 125mm, 130mm, 135mm, 140mm, 145mm, 150mm, 155mm, 160mm, 165mm, 170mm, 175mm, 180mm, 185mm, 190mm, 195mm, or 200mm, etc.

[0235] Similarly, the positive electrode active material of the electrode assembly 22 includes lithium phosphate, and the length of the main body 221 in the first direction X is 200mm-350mm. That is, the positive electrode active material layer of the positive electrode sheet 2211 of the electrode assembly 22 includes at least one of lithium iron phosphate, a composite material of lithium iron phosphate and carbon, lithium manganese phosphate, a composite material of lithium manganese phosphate and carbon, lithium manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon. Then the length of the main body 221 of the electrode assembly 22 in the first direction X is L, which satisfies 200mm≤L≤350mm.

[0236] For example, in an embodiment where the positive electrode active material of the electrode assembly 22 includes lithium phosphate, the length L of the main body portion 221 of the electrode assembly 22 in the first direction X can be 200mm, 205mm, 210mm, 215mm, 220mm, 225mm, 230mm, 235mm, 240mm, 245mm, 250mm, 255mm, 260mm, 265mm, 270mm, 275mm, 280mm, 285mm, 290mm, 295mm, 300mm, 305mm, 310mm, 315mm, 320mm, 325mm, 330mm, 335mm, 340mm, 345mm, or 350mm, etc.

[0237] In this embodiment, when the positive electrode active material of the electrode assembly 22 includes lithium transition metal oxide and the length of the main body 221 of the electrode assembly 22 in the first direction X is 100mm to 200mm, or when the positive electrode active material of the electrode assembly 22 includes lithium phosphate and the length of the main body 221 of the electrode assembly 22 in the first direction X is 200mm to 3500mm, the current demand of the electrode segment 221a of the main body 221 is greater. Therefore, setting the sum of the cross-sectional areas of the first ends 2221 of the first tabs 222 on all the first electrode segments 2211a in the first stacked region 221c to be greater than the sum of the cross-sectional areas of the first ends 2221 of the first tabs 222 on all the first electrode segments 2211a in the two second stacked regions 221d can effectively alleviate the risk of lithium plating caused by poor electrolyte wetting effect of the inner electrode segment 221a of the electrode assembly 22, thereby improving the reliability of the battery cell 20.

[0238] In some embodiments, see Figure 5 as well as Figure 12 As shown, the positive electrode active material of electrode assembly 22 includes lithium transition metal oxide, and L further satisfies 110mm≤L≤180mm.

[0239] In this embodiment, by setting the length of the main body 221 of the electrode assembly 22, whose positive electrode active material includes lithium transition metal oxide, in the first direction X to be 110 mm to 180 mm, it is possible to increase the energy density of the electrode assembly 22 while reducing the manufacturing difficulty of the electrode assembly 22, and to alleviate the phenomenon that the electrolyte wetting of the inner electrode segment 221a of the electrode assembly 22 is difficult.

[0240] In some embodiments, please continue to see Figure 5 as well as Figure 12 As shown, the positive electrode active material of electrode assembly 22 includes lithium transition metal oxide, and L further satisfies 120mm≤L≤160mm.

[0241] In this embodiment, by further setting the length of the main body 221 of the electrode assembly 22, whose positive electrode active material includes lithium transition metal oxide, in the first direction X to 120 mm to 160 mm, it is possible to increase the energy density of the electrode assembly 22 while further reducing the manufacturing difficulty of the electrode assembly 22, and further alleviate the phenomenon that the electrolyte wetting of the inner electrode segment 221a of the electrode assembly 22 is difficult.

[0242] In some embodiments, please continue to see Figure 5 as well as Figure 12 As shown, the positive electrode active material of electrode assembly 22 includes lithium phosphate, and L further satisfies 210mm≤L≤340mm.

[0243] In this embodiment, by setting the length of the main body 221 of the positive electrode active material, including the lithium phosphate-containing electrode assembly 22, in the first direction X to be 210 mm to 340 mm, the energy density of the electrode assembly 22 can be increased while the manufacturing difficulty of the electrode assembly 22 can be reduced, and the phenomenon that the electrolyte wetting of the inner electrode segment 221a of the electrode assembly 22 is difficult can be alleviated.

[0244] In some embodiments, please continue to see Figure 5 as well as Figure 12 As shown, the positive electrode active material of electrode assembly 22 includes lithium phosphate, and L further satisfies 220mm≤L≤330mm.

[0245] In this embodiment, by further setting the length of the main body 221 of the positive electrode active material, including the lithium phosphate-containing electrode assembly 22, in the first direction X to 220mm to 330mm, the energy density of the electrode assembly 22 can be increased while the manufacturing difficulty of the electrode assembly 22 can be further reduced, and the phenomenon that the electrolyte wetting of the inner electrode segment 221a of the electrode assembly 22 is difficult can be further alleviated.

[0246] According to some embodiments of this application, see Figure 5 as well as Figure 12 As shown, the width of the main body 221 in the third direction Z is W, which satisfies 200mm≤W≤400mm, and the first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0247] For example, the width W of the main body 221 in the third direction Z can be 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 300mm, 310mm, 320mm, 330mm, 340mm, 350mm, 360mm, 370mm, 380mm, 390mm or 400mm, etc.

[0248] In this embodiment, by setting the width of the main body 221 of the electrode assembly 22 in the third direction Z to 200mm to 400mm, the size of the electrode assembly 22 can be increased to improve the energy density of the battery cell 20. Since the overcurrent demand of the electrode segment 221a of the main body 221 is greater when the width of the main body 221 in the third direction Z is 200mm to 400mm, the structure of setting the sum of the cross-sectional areas of the first ends 2221 of the first tabs 222 on all the first electrode segments 2211a in the first stacked region 221c to be greater than the sum of the cross-sectional areas of the first ends 2221 of the first tabs 222 on all the first electrode segments 2211a in the two second stacked regions 221d can effectively alleviate the risk of lithium plating caused by poor electrolyte wetting effect of the inner electrode segments 221a of the electrode assembly 22, thereby improving the reliability of the battery cell 20.

[0249] In some embodiments, please continue to see Figure 5 as well as Figure 12 As shown, 200mm≤W≤350mm.

[0250] In this embodiment, by further setting the width of the main body 221 of the electrode assembly 22 in the third direction Z to 200mm to 350mm, the energy density of the electrode assembly 22 can be increased while the manufacturing difficulty of the electrode assembly 22 can be further reduced, and the phenomenon that the electrolyte wetting of the inner electrode segment 221a of the electrode assembly 22 is difficult can be further alleviated.

[0251] In some embodiments, please continue to see Figure 5 as well as Figure 12 As shown, 220mm≤W≤340mm.

[0252] In this embodiment, by further setting the width of the main body 221 of the electrode assembly 22 in the third direction Z to 220mm to 340mm, the manufacturing difficulty of the electrode assembly 22 can be further reduced while increasing the energy density of the electrode assembly 22, and the phenomenon that the electrolyte wetting of the inner electrode segment 221a of the electrode assembly 22 is difficult can be further alleviated.

[0253] According to some embodiments of this application, see Figure 5 and Figure 6 , Figure 8 , Figure 9 as well as Figure 12 and Figure 13 As shown, the electrode assembly 22 also includes a plurality of second electrode tabs 223, which are connected to one end of the main body 221 in the first direction X and are stacked. The plurality of electrode segments 221a also include a plurality of second electrode segments 2212a with the same polarity. The polarity of the second electrode segments 2212a is opposite to that of the first electrode segments 2211a. Each second electrode tab 223 is connected to a second electrode segment 2212a, and the second electrode tab 223 has a second end 2231 connected to the corresponding second electrode segment 2212a. The difference between the number of second pole segments 2212a in the first stacked region 221c and the sum of the number of second pole segments 2212a in the two second stacked regions 221d is less than or equal to 1, and the number of second pole segments 2212a in the two second stacked regions 221d is the same. In the same cross-section perpendicular to the first direction X, the sum of the cross-sectional areas of the second ends 2231 of all the second pole tabs 223 in the first stacked region 221c is greater than the sum of the cross-sectional areas of the second ends 2231 of all the second pole tabs 223 in the two second stacked regions 221d.

[0254] In this configuration, multiple second electrodes 223 are connected to one end of the main body 221 in the first direction X and are stacked together. That is, the multiple second electrodes 223 are an integral structure formed by stacking each other along their thickness direction. It should be noted that the multiple second electrodes 223 can form a connection structure, such as a welded connection, that is, the multiple second electrodes 223 are stacked and welded together. Of course, the multiple second electrodes 223 can also be a structure that is only stacked together and is not connected to each other.

[0255] For example, the first electrode 222 and the second electrode 223 are both connected to the same end of the main body 221 in the first direction X, and the plurality of first electrodes 222 and the plurality of second electrodes 223 are arranged at intervals along the third direction Z.

[0256] Each second pole piece 223 is connected to a second pole piece 2212a, that is, the multiple second pole pieces 223 are arranged along the second direction Y. In other words, the connection position of the multiple second pole pieces 223 to the main body 221 is arranged along the second direction Y.

[0257] The second tab 223 has a second end 2231 connected to the corresponding second electrode segment 2212a. That is, the second end 2231 is the root of the second tab 223 connected to the corresponding second electrode segment 2212a, and correspondingly, the second end 2231 is also the root of the second tab 223. It should be noted that in the embodiment where the second electrode segment 2212a includes a second current collector and a second active material layer disposed on at least one side of the second current collector, and the second tab 223 is connected to one end of the second current collector of the second electrode segment 2212a in the first direction X, then the second end 2231 is the end of the second tab 223 connected to the second current collector.

[0258] The second electrode segment 2212a and the first electrode segment 2211a have opposite polarities, that is, the first electrode segment 2211a and the second electrode segment 2212a are respectively a part of the positive electrode 2211 and a part of the negative electrode 2212, or respectively the positive electrode 2211 and the negative electrode 2212. Correspondingly, the first electrode tab 222 and the second electrode tab 223 have structures with opposite polarities.

[0259] The difference between the number of second pole pieces 2212a in the first stacked region 221c and the sum of the number of second pole pieces 2212a in the two second stacked regions 221d is less than or equal to 1, and the number of second pole pieces 2212a in the two second stacked regions 221d is the same. That is, in the second direction Y, the number of second pole pieces 2212a on one side of the first stacked region 221c is the same as the number of second pole pieces 2212a on the other side of the first stacked region 221c, and the sum of the number of second pole pieces 2212a on both sides of the first stacked region 221c is equal to the number of second pole pieces in the first stacked region 221c. The number of segments 2212a is either equal or the difference is equal to 1. That is, the sum of the number of second pole segments 2212a on both sides of the first stacked region 221c is equal to the number of second pole segments 2212a in the first stacked region 221c. Alternatively, the sum of the number of second pole segments 2212a on both sides of the first stacked region 221c is one more than the number of second pole segments 2212a in the first stacked region 221c. Or, the sum of the number of second pole segments 2212a on both sides of the first stacked region 221c is one less than the number of second pole segments 2212a in the first stacked region 221c.

[0260] Within the same cross-section perpendicular to the first direction X, the sum of the cross-sectional areas of the second ends 2231 of all the second pole tabs 223 within the first stacked region 221c is greater than the sum of the cross-sectional areas of the second ends 2231 of all the second pole tabs 223 within the two second stacked regions 221d. That is, within the same cross-section, and this cross-section is a plane perpendicular to the first direction X, the roots of the second pole tabs 223 on all the second pole segments 2212a within the first stacked region 221c are perpendicular to the cross-section in the first direction X. The sum of the areas is greater than the sum of the areas of the cross sections of the roots of the second pole pieces 2212a on all the second pole pieces 2212a located in the two second stacked regions 221d perpendicular to the first direction X. Correspondingly, the total flow area between the multiple second pole pieces 2212a located in the first stacked region 221c and the corresponding multiple second pole pieces 223 is greater than the total flow area between the multiple second pole pieces 2212a located in the two second stacked regions 221d and the corresponding multiple second pole pieces 223.

[0261] Optionally, in Figure 6 , Figure 8 , Figure 9 as well as Figure 13 In the process, among two adjacent second tabs 223, in the same cross-section perpendicular to the first direction X, along the second direction Y, the cross-sectional area of ​​the second end 2231 of the second tab 223 closer to the center of the electrode assembly 22 is greater than the cross-sectional area of ​​the second end 2231 of the second tab 223 farther from the center of the electrode assembly 22. That is, among the multiple second tabs 223 arranged along the second direction Y, and in the same cross-section perpendicular to the first direction X, the area of ​​the cross-section of the root of the second tab 223 closer to the center of the electrode assembly 22 is larger, so that the cross-section of the root of the multiple second tabs 223 has a structure that gradually decreases from the center of the electrode assembly 22 to at least one side. Correspondingly, the flow area between the multiple second tabs 223 and the corresponding second electrode segment 2212a has a structure that gradually decreases from the center of the electrode assembly 22 to at least one side.

[0262] For example, along the second direction Y, in two adjacent second tabs 223, in the same cross section perpendicular to the first direction X, the width of the second end 2231 of the second tab 223 near the center of the electrode assembly 22 in the third direction Z is greater than the width of the second end 2231 of the second tab 223 away from the center of the electrode assembly 22 in the third direction Z, and the second ends 2231 of the plurality of second tabs 223 have the same thickness in the second direction Y.

[0263] In this embodiment, one end of the main body 221 of the electrode assembly 22 in the first direction X is further connected to a plurality of stacked second tabs 223. Each second tab 223 is connected to a second electrode segment 2212a, and the polarity of the second electrode segment 2212a is opposite to that of the first electrode segment 2211a, so that the second tabs 223 and the first tabs 222 can cooperate to input or output electrical energy of the electrode assembly 22. The connection positions of the stacked second tabs 223 to the main body 221 are also arranged along the second direction Y. In this embodiment, by setting the sum of the cross-sectional areas of the second ends 2231 of the second tabs 223 on all the second electrode segments 2212a in the first stacked region 221c to be greater than the sum of the cross-sectional areas of the second ends 2231 of the second tabs 223 on all the second electrode segments 2212a in the two second stacked regions 221d, the roots of all the second tabs 223 in the first stacked region 221c are... The sum of the cross-sectional areas is greater than the sum of the cross-sectional areas of the roots of all the second tabs 223 within the two second stacked regions 221d. This makes the area of ​​the second electrode segment 2212a located near the center of the electrode assembly 22 in the main body 221 that conducts current through the second tab 223 larger than the area of ​​the second electrode segment 2212a located on the outer side of the electrode assembly 22 in the main body 221 that conducts current through the second tab 223. This improves the current path and current demand of the second electrode segment 2212a located near the center in the main body 221 of the electrode assembly 22, thereby alleviating the phenomenon of limited electron transport path of the second electrode segment 2212a located near the center of the electrode assembly 22 through the second tab 223. Furthermore, it can further reduce the risk of lithium plating caused by poor electrolyte wetting effect of the electrode segment 221a on the inner side of the main body 221 compared to the outer electrode segment 221a, thereby further improving the reliability of the battery cell 20.

[0264] According to some embodiments of this application, this application also provides a battery device 100, which includes a battery cell 20 of any of the above schemes.

[0265] Among them, see Figure 2 As shown, the battery device 100 may also include a housing 10, in which the battery cells 20 are housed.

[0266] In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, the first housing body 11 and the second housing body 12 covering each other, the first housing body 11 and the second housing body 12 together defining an assembly space for accommodating the battery cell 20.

[0267] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure. The first box body 11 covers the open side of the second box body 12 so that the first box body 11 and the second box body 12 together define the assembly space; the first box body 11 and the second box body 12 can also be hollow structures with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0268] Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder or a cuboid. For example, in... Figure 2 In the middle, box 10 has a rectangular structure.

[0269] Optionally, the battery cell 20 disposed within the housing 10 can be one or more. For example, in... Figure 2 In the battery device 100, multiple battery cells 20 are arranged inside the housing 10. The multiple battery cells 20 can be connected in series, parallel, or in a mixed manner. A mixed connection means that the multiple battery cells 20 are connected in both series and parallel. The multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of the multiple battery cells 20 is housed in the housing 10. Of course, the battery device 100 can also be formed by first connecting multiple battery cells 20 in series, parallel, or in a mixed manner to form a battery module, and then connecting multiple battery modules in series, parallel, or in a mixed manner to form a whole assembly, which is also housed in the housing 10.

[0270] The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component that connects multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20.

[0271] It should be noted that in some embodiments, the battery device 100 may not have a housing 10. The battery device 100 includes multiple battery cells 20, and the battery device 100 composed of multiple battery cells 20 can be directly mounted onto the electrical device to provide power to the electrical device through the multiple battery cells 20. That is, the housing 10 can be part of the electrical device. Taking a vehicle 1000 as an example, the housing 10 can be part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 can be at least a part of the floor of the vehicle 1000, or a portion of the housing 10 can be at least a part of the crossbeams and longitudinal beams of the vehicle 1000.

[0272] According to some embodiments of this application, this application also provides an electrical device, which includes a battery cell 20 of any of the above schemes, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0273] The electrical device can be any of the aforementioned devices or systems that utilize battery cells 20.

[0274] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0275] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: shell; as well as At least one electrode assembly is housed within the housing. The electrode assembly includes a main body and a plurality of first electrode tabs. The plurality of first electrode tabs are connected to one end of the main body in a first direction and are stacked. The main body includes a plurality of electrode segments stacked along a second direction. The plurality of electrode segments include a plurality of first electrode segments with the same polarity. Each first electrode tab is connected to a first electrode segment, and the first electrode tab has a first end connected to the corresponding first electrode segment. The first direction is perpendicular to the second direction. The main body has a first stacked region and two second stacked regions. The first stacked region is located between the two second stacked regions in the second direction. The difference between the number of first pole segments in the first stacked region and the sum of the number of first pole segments in the two second stacked regions is less than or equal to 1, and the number of first pole segments in the two second stacked regions is the same. In the same cross-section perpendicular to the first direction, the sum of the cross-sectional areas of the first ends of all the first pole tabs in the first stacked region is greater than the sum of the cross-sectional areas of the first ends of all the first pole tabs in the two second stacked regions.

2. The battery cell according to claim 1, characterized in that, The electrode assembly has a wound structure, and the winding center axis of the electrode assembly extends along the first direction. The main body further includes multiple bending segments, including a first bending segment along the winding direction of the electrode assembly. The first bending segment connects two adjacent first electrode segments, and the first bending segment and the first electrode segments are alternately arranged.

3. The battery cell according to claim 2, characterized in that, The first pole segment in the first stacked region and the first pole segments in the two second stacked regions are all connected to the first pole tab; or Along the second direction, the first electrode segment located on one side of the center position of the electrode assembly is connected to the first electrode tab.

4. The battery cell according to claim 3, characterized in that, In two adjacent first tabs, in the same cross-section perpendicular to the first direction, along the second direction, the cross-sectional area of ​​the first end of the first tab closer to the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first tab farther from the center of the electrode assembly.

5. The battery cell according to claim 4, characterized in that, In two adjacent first tabs, in the same cross section perpendicular to the first direction, the width of the first end of the first tab closer to the center of the electrode assembly in the third direction is greater than the width of the first end of the first tab farther from the center of the electrode assembly in the third direction, wherein the first direction, the second direction, and the third direction are perpendicular to each other.

6. The battery cell according to claim 5, characterized in that, Within the same cross-section perpendicular to the first direction, the first ends of the plurality of first tabs have the same thickness in the second direction.

7. The battery cell according to claim 5, characterized in that, In two adjacent first tabs, the first tab closer to the center of the electrode assembly extends along the third direction beyond the two ends of the first tab farther from the center of the electrode assembly in the third direction.

8. The battery cell according to claim 4, characterized in that, In two adjacent first tabs, in the same cross-section perpendicular to the first direction, the thickness of the first end of the first tab closer to the center of the electrode assembly in the second direction is greater than the thickness of the first end of the first tab farther from the center of the electrode assembly in the second direction.

9. The battery cell according to claim 8, characterized in that, Within the same cross-section perpendicular to the first direction, the first ends of the plurality of first tabs have the same width in the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other.

10. The battery cell according to claim 2, characterized in that, The first pole segments in the first stacked region are all connected to the first pole tabs, and only one of the two second stacked regions has the first pole segments all connected to the first pole tabs; In the same cross-section perpendicular to the first direction, the first ends of the plurality of first electrodes have the same thickness in the second direction, and the first ends of the plurality of first electrodes have the same width in the third direction. The first direction, the second direction, and the third direction are perpendicular to each other.

11. The battery cell according to claim 1, characterized in that, The electrode assembly has a stacked structure, and the multiple electrode segments further include multiple second electrode segments with the same polarity. The second electrode segments and the first electrode segments are stacked and alternately arranged along the second direction. One of the first electrode segments and the second electrode segments is a positive electrode and the other is a negative electrode. Each of the first electrode segments is connected to a first electrode tab. In two adjacent first electrode tabs, in the same cross-section perpendicular to the first direction, along the second direction, the cross-sectional area of ​​the first end of the first electrode tab closer to the center of the electrode assembly is greater than the cross-sectional area of ​​the first end of the first electrode tab farther from the center of the electrode assembly.

12. The battery cell according to claim 11, characterized in that, In two adjacent first tabs, in the same cross section perpendicular to the first direction, the width of the first end of the first tab closer to the center of the electrode assembly in the third direction is greater than the width of the first end of the first tab farther from the center of the electrode assembly in the third direction, wherein the first direction, the second direction, and the third direction are perpendicular to each other.

13. The battery cell according to claim 12, characterized in that, Within the same cross-section perpendicular to the first direction, the first ends of the plurality of first tabs have the same thickness in the second direction.

14. The battery cell according to claim 12, characterized in that, In two adjacent first tabs, the first tab closer to the center of the electrode assembly extends along the third direction beyond the two ends of the first tab farther from the center of the electrode assembly in the third direction.

15. The battery cell according to claim 11, characterized in that, In two adjacent first tabs, in the same cross-section perpendicular to the first direction, the thickness of the first end of the first tab closer to the center of the electrode assembly in the second direction is greater than the thickness of the first end of the first tab farther from the center of the electrode assembly in the second direction.

16. The battery cell according to claim 15, characterized in that, Within the same cross-section perpendicular to the first direction, the first ends of the plurality of first tabs have the same width in the third direction, and the first direction, the second direction, and the third direction are perpendicular to each other.

17. The battery cell according to claim 1, characterized in that, The first electrode segment includes a first current collector and a first active material layer disposed on at least one side of the first current collector, and the first electrode tab is connected to one end of the first current collector in the first direction; Wherein, the first electrode tab is integrally formed with the first current collector; or The first electrode tab and the first current collector are separately configured.

18. The battery cell according to any one of claims 1-17, characterized in that, The width of the main body in the third direction is W, which satisfies 200mm≤W≤400mm, and the first direction, the second direction and the third direction are perpendicular to each other.

19. The battery cell according to claim 18, characterized in that, 200mm≤W≤350mm.

20. The battery cell according to claim 19, characterized in that, 220mm≤W≤340mm.

21. The battery cell according to claim 1, characterized in that, The electrode assembly further includes a plurality of second electrodes connected to one end of the main body in the first direction and stacked thereon. The plurality of electrode segments further include a plurality of second electrode segments with the same polarity. The polarity of the second electrode segments is opposite to that of the first electrode segments. Each second electrode is connected to a second electrode segment, and the second electrode has a second end connected to the corresponding second electrode segment. Wherein, the difference between the number of second pole segments in the first stacked region and the sum of the number of second pole segments in the two second stacked regions is less than or equal to 1, and the number of second pole segments in the two second stacked regions is the same. In the same cross-section perpendicular to the first direction, the sum of the cross-sectional areas of the second ends of all the second pole tabs in the first stacked region is greater than the sum of the cross-sectional areas of the second ends of all the second pole tabs in the two second stacked regions.

22. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-21.

23. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-21, the battery cell being used to provide electrical energy.

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