Battery cell, cylindrical battery and power utilization device
By setting inner, middle and outer ring tab areas on the end face of the battery cell body and optimizing the tab layout, the tab bending problem of full-tab large cylindrical batteries is solved, achieving a larger flow area and higher thermal stability and safety performance.
Patent Information
- Application Number
- CN202422568013.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-23
- Publication Date
- 2025-09-16
- Estimated Expiration
- 2034-10-23
AI Technical Summary
The tabs of the large cylindrical battery cell with full tabs are bent toward the center hole, resulting in no tabs near the center hole, which affects the electrolyte infiltration effect of the battery cell and the torque welding process, resulting in large AC internal resistance and insufficient thermal stability and safety performance.
The end face of the battery cell body is designed to have inner, middle and outer ring tab areas from the inside to the outside. The tab height gradually changes, the inner and outer ring tabs are bent toward the center axis, and the middle tab does not need to be bent. The number and area of the tabs are increased, and the tab layout is optimized to increase the flow area.
It increases the flow area of the battery cell, reduces the DC internal resistance, improves thermal stability and safety performance, and ensures effective welding and flatness between the tabs and mechanical parts.
Smart Images
Figure CN223347867U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a battery core, a cylindrical battery and an electrical device. Background Art
[0002] Large cylindrical cells with full tabs are widely used in large cylindrical batteries and electrical devices due to their high energy density, excellent heat dissipation, and low cost. Compared to traditional small cylindrical cells with welded tabs, large cylindrical cells with full tabs have a larger flow area, which helps reduce internal resistance between components and the heat dissipation area. Their AC internal resistance can be reduced by dozens of times compared to small cylindrical cells.
[0003] In the existing technology, the tabs of large cylindrical cells with full tabs are all bent toward the center hole, resulting in the inability to retain the tabs in the area near the center hole. This is because the tabs near the center hole, when bent toward the center hole, block the center hole, which in turn affects the electrolyte infiltration effect of the cell and also affects the torque welding process, resulting in assembly failure. Since large cylindrical cells with full tabs do not have tabs near the center hole, the tab area of large cylindrical cells with full tabs is still relatively small, resulting in a large AC internal resistance, which in turn leaves room for further improvement in the thermal stability and safety performance of large cylindrical cells with full tabs. Utility Model Content
[0004] The first object of the present invention is to provide a battery cell with a large flow area, high thermal stability and safety performance;
[0005] The second object of the present invention is to provide a cylindrical battery with high thermal stability and safety performance;
[0006] The third object of the present invention is to provide an electrical device with higher safety performance.
[0007] To achieve this purpose, the present invention adopts the following technical solutions:
[0008] Provided is a battery cell, comprising:
[0009] A battery cell body, the battery cell body comprising multiple layers of wound pole pieces;
[0010] There are multiple pole tabs, and each layer of the pole piece is provided with at least one pole tab;
[0011] The tab is located on the end face of the battery cell body, and the end face of the battery cell body includes an inner ring tab area, an intermediate tab area and an outer ring tab area arranged in sequence from the inside to the outside along the radial direction of the battery cell body; the height of the tab in the intermediate tab area is less than the height of the tab in the inner ring tab area, and less than the height of the tab in the outer ring tab area, the tab in the inner ring tab area is bent away from the central axis of the battery cell body, and the tab in the outer ring tab area is bent toward the central axis of the battery cell body.
[0012] Optionally, the tabs in the inner ring tab region have the same height, and the height difference between the tabs in the middle tab region and the tabs in the inner ring tab region is 2 mm to 3 mm; and / or,
[0013] The heights of the tabs in the outer ring tab region are consistent, and the height difference between the tabs in the middle tab region and the tabs in the outer ring tab region is 2 mm to 3 mm.
[0014] Optionally, the height of the tabs in the outer ring tab region gradually increases in the direction outward from the center of the battery cell body; and / or the height of the tabs in the inner ring tab region gradually decreases in the direction outward from the center of the battery cell body.
[0015] Optionally, the difference between the height of the tab in the middle tab region and the minimum height of the tab in the outer ring tab region or the inner ring tab region is 1 mm-2 mm.
[0016] Optionally, the number of pole pieces in the inner ring tab region is N, the number of pole pieces in the middle tab region is N-1.5N, and the number of pole pieces in the outer ring tab region is N-1.5N.
[0017] Optionally, the tabs in the inner ring tab region and the tabs in the outer ring tab region cooperate with each other and cover the middle tab region.
[0018] Optionally, in the outer ring tab region, the number of tab layers covering the middle tab region is 15-50; and / or
[0019] In the inner ring tab region, the number of the tab layers covering the middle tab region is 15-50.
[0020] Optionally, the tab in the inner tab region includes a first lead portion, and one end of the first lead portion away from the cell body is bent away from the central axis of the cell body to form a first bent portion;
[0021] The tab in the middle tab region includes a second lead-out portion;
[0022] The tab in the outer ring tab region includes a third lead-out portion. An end of the third lead-out portion away from the cell body is bent toward the central axis of the cell body to form a second bent portion.
[0023] Also provided is a cylindrical battery comprising the battery cell described above.
[0024] Also provided is an electrical device comprising the battery cell described above, or comprising the cylindrical battery described above.
[0025] Beneficial effects of the utility model:
[0026] The battery cell, cylindrical battery and electrical device provided by the present invention have an end face of the battery cell body including an inner ring pole ear area, an intermediate pole ear area and an outer ring pole ear area arranged in sequence in the direction from the central axis of the battery cell body to the edge. The inner ring pole ear area, the intermediate pole ear area and the outer ring pole ear area are all provided with pole ears, thereby increasing the number of pole ears and the pole ear area for connecting mechanical parts, thereby increasing the flow area, and can effectively reduce the DC internal resistance of the battery cell. At the same time, due to the increase in the flow area, the heat per unit area when the current passes through is reduced, which is beneficial to the improvement of the thermal stability of the battery cell, thereby improving the safety performance of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Figure 1 This is a front view of the battery cell provided by an embodiment of the present utility model;
[0028] Figure 2 This is a top view of a battery cell provided by an embodiment of the present utility model;
[0029] Figure 3 This is a first partial schematic diagram of a battery cell provided by an embodiment of the present invention after the tab is flattened;
[0030] Figure 4 This is a second partial schematic diagram of the battery cell provided by an embodiment of the present invention after the tabs are flattened.
[0031] In the picture:
[0032] 100, battery cell body; 110, inner ring tab area; 120, middle tab area; 130, outer ring tab area; 140, center hole;
[0033] 200, electrode tab; 211, first lead-out portion; 212, first bend portion; 221, second lead-out portion; 231, third lead-out portion; 232, second bend portion; 240, positive electrode tab; 250, negative electrode tab. DETAILED DESCRIPTION
[0034] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all of its components.
[0035] In the description of this utility model, unless otherwise specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection or electrical connection; direct connection or indirect connection through an intermediate medium; internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on the specific circumstances.
[0036] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.
[0037] In the description of this embodiment, the terms "upper," "lower," "right," and other orientations or positional relationships are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely for ease of description and simplified operation. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.
[0038] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.
[0039] In a first aspect, this embodiment provides a battery cell that can have high thermal stability and safety.
[0040] Example 1
[0041] like Figures 1 to 4As shown, the battery cell includes a battery cell body 100 and a tab 200. The battery cell body 100 includes multiple layers of wound pole pieces (not shown in the figure). That is, the battery cell in this embodiment is a wound battery cell. Each layer of pole piece is provided with at least one tab 200, that is, the tab 200 in this embodiment is provided with multiple tabs. It should be noted that, as shown in FIG. Figure 2 As shown, each layer of pole pieces is covered with pole tabs 200 along the circumferential direction, so that the number and area of the pole tabs 200 can be larger.
[0042] See Figure 1 , the tab 200 is located at the end surface of the cell body 100, and the end surface of at least one end of the cell body 100 is provided with a tab 200. Figure 2 As shown, the end face of the cell body 100 includes an inner ring tab area 110, a middle tab area 120 and an outer ring tab area 130 arranged in sequence from the inside to the outside along the radial direction of the cell body 100 (i.e., the direction perpendicular to the axial direction of the cell body 100).
[0043] In this embodiment, Figure 1 As shown, both ends of the cell body 100 have tabs 200, and the tabs 200 at both ends of the cell body 100 have opposite polarities. The following description of this embodiment uses the tab 200 on one end of the cell body 100 as an example. For the characteristics of the tab 200 on the other end of the cell body 100, please refer to the characteristics of the tab 200 on that end, and the description will not be repeated. In this embodiment, the tab 200 on one end of the cell body 100 is referred to as the positive electrode tab 240, and the tab on the other end is referred to as the negative electrode tab 250.
[0044] The height of the tab 200 in the middle tab region 120 is less than the height of the tab 200 in the inner tab region 110, and less than the height of the tab 200 in the outer tab region 130. That is, the tab 200 in the middle tab region 120 is the smallest. Furthermore, the tab 200 in the inner tab region 110 is bent away from the central axis of the cell body 100, while the tab 200 in the outer tab region 130 is bent toward the central axis of the cell body 100. The tab 200 in the middle tab region 120 may be bent toward the central axis, may be bent away from the central axis, or may not be bent, and this is not limited in this embodiment. In this embodiment, the tabs 200 of the inner ring tab region 110 and the tabs 200 of the outer ring tab region 130 are both bent toward the middle tab region 120. Since the tabs 200 of the middle tab region 120 are relatively small in height, they do not need to be bent. Therefore, even if the tabs 200 of the inner ring tab region 110 and the tabs 200 of the outer ring tab region 130 overlap in the middle tab region 120, it will not affect the flatness of the surface of the tabs 200 after being flattened.
[0045] In addition, if Figure 2As shown, the battery cell body 100 generally also includes a center hole 140, and the inner ring tab area 110 is arranged around the outer circumference of the center hole 140. By bending the tabs 200 of the inner ring tab area 110 back to the center axis, the tabs 200 will not block the center hole 140 after being flattened.
[0046] It should be noted that for pole pieces of the same length, the overcurrent area of the tab 200 can be larger and the AC internal resistance can be smaller, thereby reducing the ohmic impedance of the battery cell. At the same time, the increase in the area of the tab 200 can disperse the heat generated by high-rate charging and discharging of the battery cell. The same amount of heat is generated, but the area through which the current flows increases, and the heat is not concentrated, so the heat is easier to dissipate, which is more conducive to the thermal stability of the battery cell and improves the safety performance of the single battery cell.
[0047] In the battery cell provided in this embodiment, the end face of the battery cell body 100 includes an inner ring pole lug area 110, an intermediate pole lug area 120 and an outer ring pole lug area 130 arranged in sequence in the direction from the central axis of the battery cell body 100 to the edge. The inner ring pole lug area 110, the intermediate pole lug area 120 and the outer ring pole lug area 130 are all provided with pole lugs 200, thereby increasing the number of pole lugs 200 and the area of the pole lugs 200 for connecting mechanical parts (such as collectors), thereby increasing the flow area, which can effectively reduce the DC internal resistance of the battery cell. At the same time, due to the increase in the flow area, the heat per unit area when the current passes through is reduced, which is beneficial to the improvement of the thermal stability of the battery cell, thereby improving the safety performance of the battery cell.
[0048] In addition, the height of the tab 200 in the middle tab area 120 is set to be smaller, so that the tab 200 in the middle tab area 120 does not need to be bent, or the part that needs to be bent is shorter, so that the thickness of the tab 200 in the inner ring tab area 110 and the tab 200 in the outer ring tab area 130 after bending in the middle tab area 120 will not be too large, which is convenient for flattening the tab 200, and thus can ensure that the tab 200 has a larger contact area when connected to a mechanical part (such as a busbar).
[0049] In some optional embodiments, the tabs 200 in the inner tab region 110 are of uniform height, and the tabs 200 in the middle tab region 120 are also of uniform height, and the height difference between the tabs 200 in the middle tab region 120 and the tabs 200 in the inner tab region 110 is 2 mm to 3 mm. If the height difference between the tabs 200 in the middle tab region 120 and the tabs 200 in the inner tab region 110 is too large, there is a risk that the tabs 200 in the inner tab region 110 will bend away from the central axis of the cell body 100 and extend to the outer tab region 130, thereby interfering with the tabs 200 in the outer tab region 130. Furthermore, the excessively high stacking height in the middle tab region 120 may result in poor flattening, thereby affecting welding of the tabs 200 to mechanical components (e.g., busbars). If the height difference between the tabs 200 in the middle tab region 120 and the tabs 200 in the inner tab region 110 is too small, the area of the tabs 200 will be small, which is not conducive to increasing the area of the tabs 200. For example, the height difference between the tabs 200 in the middle tab region 120 and the tabs 200 in the inner tab region 110 is 2 mm, 2.5 mm, 2.8 mm, and 3 mm.
[0050] Optionally, the tabs 200 in the outer tab region 130 are of uniform height, and the height difference between the tabs 200 in the middle tab region 120 and the outer tab region 130 is 2 mm to 3 mm. If the height difference between the tabs 200 in the middle tab region 120 and the outer tab region 130 is too large, there is a risk that the tabs 200 in the outer tab region 130 will bend toward the central axis of the cell body 100 and extend to the inner tab region 110, thereby interfering with the tabs 200 in the inner tab region 110. Furthermore, the excessively high stacking height in the middle tab region 120 may result in poor flattening, affecting welding of the tabs 200 to mechanical components (e.g., busbars). If the height difference between the tabs 200 in the middle tab region 120 and the tabs 200 in the outer tab region 130 is too small, the area of the tabs 200 will be small, which is not conducive to increasing the area of the tabs 200. For example, the height difference between the tabs 200 in the middle tab region 120 and the tabs 200 in the outer tab region 130 is 2 mm, 2.5 mm, 2.8 mm, and 3 mm.
[0051] In some optional embodiments, the number of pole pieces in the inner tab region 110 is N, the number of pole pieces in the middle tab region 120 is N-2N, and the number of pole pieces in the outer tab region 130 is N-3N. This arrangement helps control the thickness of the tab 200 in the middle tab region 120 after the tab 200 is flattened, preventing it from being too thin and potentially being welded through during laser welding of the tab 200 to a mechanical component (e.g., a busbar). It also prevents the tab 200 in the middle tab region 120 from being too thick after flattening, preventing the multi-layer tab 200 near the bottom of the cell body 100 from being effectively welded, thus affecting welding quality. For example, the number of pole pieces in the middle tab region 120 is N, 1.5N, and 2N. The number of pole pieces in the outer tab region 130 is N, 1.5N, 2N, 2.5N, 2.8N, and 3N.
[0052] For example, the number of pole pieces in the inner ring tab region 110 is 0-30, the number of pole pieces in the middle tab region 120 is 30-60, and the number of pole pieces in the outer ring tab region 130 is 60-80.
[0053] For example, Figure 3 or Figure 4 As shown, the tabs 200 of the inner ring tab region 110 and the tabs 200 of the outer ring tab region 130 cooperate with each other and cover the middle tab region 120, so as to avoid the situation where the tabs 200 of the middle tab region 120 are shorter and thus the tabs 200 in this region cannot be effectively welded to the mechanical parts (such as the busbar), resulting in a welding leak. In this embodiment, the tabs 200 of the middle tab region 120 are welded to the tabs 200 of the inner ring tab region 110 and the outer ring tab region 130 covering them, so that current can flow from the tabs 200 of the middle tab region 120 to the tabs 200 of the outer ring tab region 130 and the inner ring tab region 110, and then be transferred to the mechanical parts (such as the busbar), realizing the input and output of current, thereby dispersing the current in the battery cell body 100 over multiple tabs, avoiding the problem of heat concentration and facilitating heat dissipation.
[0054] Illustratively, in the outer ring tab region 130 , the number of layers of tabs 200 covering the middle tab region 120 is 15-50; that is, the tabs 200 in the outer ring tab region 130 may be entirely covered in the middle tab region 120 , or partially covered in the middle tab region 120 while the other partially covers the portion of tabs 200 and does not cover the middle tab region 120 . The number of layers of the tabs 200 in the outer tab region 130 covering the middle tab region 120 cannot be too large. Too many layers will result in the tabs 200 in the middle tab region 120 being too thick after being flattened, making it impossible to effectively weld the tabs 200 in the middle tab region 120 near the cross-section of the cell body 100. However, the number of layers of the tabs 200 in the outer tab region 130 covering the middle tab region 120 cannot be too small. Too few layers will result in the tabs 200 in the middle tab region 120 being too thin after being flattened, which may risk the tabs 200 being welded through during welding. For example, the number of layers of the tabs 200 in the outer tab region 130 covering the middle tab region 120 is 15, 20, 25, 26, 30, 34, 35, 38, 40, 45, or 50.
[0055] Similarly, the number of layers of the tabs 200 in the inner ring tab area 110 covering the middle tab area 120 is 15-50; that is, the tabs 200 in the inner ring tab area 110 can be completely covered in the middle tab area 120, or a part of the tabs 200 can be covered in the middle tab area 120, while the other part covers the part of the tabs 200 and does not cover the middle tab area 120. The number of layers of the tab 200 in the inner tab region 110 covering the middle tab region 120 cannot be too large. Too many layers will result in the tab 200 in the middle tab region 120 being too thick after being flattened, making it impossible to effectively weld the tab 200 in the middle tab region 120 near the cross section of the battery cell body 100. However, the number of layers of the tab 200 in the inner tab region 110 covering the middle tab region 120 cannot be too small. Too few layers will result in the tab 200 in the middle tab region 120 being too thin after being flattened, which may cause the tab 200 to be welded through during welding. For example, the number of layers of the tab 200 in the inner tab region 110 covering the middle tab region 120 is 15, 20, 25, 26, 30, 34, 35, 38, 40, 45, or 50.
[0056] In some optional embodiments, the tabs 200 of the inner and outer tab regions 110 and 130 are bent and joined in the middle tab region 120, that is, the ends of the tabs 200 abut against each other, making them relatively flat after being flattened. In other optional embodiments, the tabs 200 of the inner and outer tab regions 110 and 130 are bent and overlapped in the middle tab region 120, so that the thickness of the tabs 200 in the middle tab region 120 after being flattened is not too thin.
[0057] In some optional embodiments, such as Figure 1 、 Figure 3 and Figure 4 As shown, the tab 200 in the inner tab region 110 includes a first lead portion 211, and the end of the first lead portion 211 away from the cell body 100 is bent away from the central axis of the cell body 100 to form a first bent portion 212. The tab 200 in the middle tab region 120 includes a second lead portion 221, that is, the tab in the middle tab region 120 is not bent. The tab 200 in the outer tab region 130 includes a third lead portion 231, and the end of the third lead portion 231 away from the cell body 100 is bent toward the central axis of the cell body 100 to form a second bent portion 232. The first bent portion 212 and the second bent portion 232 are both used for welding to mechanical parts (such as a busbar) and the tab 200 in the middle tab region 120, thereby increasing the welding area of the tab 200.
[0058] The assembly process of the battery cell provided in this embodiment is as follows: first, adjust the laser die-cutting software and set the die-cutting height of the tab 200 in the middle tab area 120, specifically to be 2-3 mm lower than the height of the tab 200 in the inner ring tab area 110 and the outer ring tab area 130. Afterwards, the tab pre-folding device is installed on the roller before winding, and the tab 200 can be pre-folded inward and outward according to the length of the wound fixed pole piece by software design to achieve the desired effect. After the pole piece winding is completed according to the specified parameters, the mechanical gripper transfers the battery cell to the conveyor belt, and transfers it to the flattening device for flattening, and flattens the pre-folded tab 200. Subsequently, the flattened battery cell is transferred to the penetration welding equipment, and the positive and negative busbars are respectively welded to the positive and negative tabs. Specifically, the positive tab 240 is connected to the positive busbar, and the negative tab 250 is connected to the negative busbar. After welding the positive and negative busbars, high-temperature insulating tape needs to be attached to the edge of the busbar. The main purpose is to insulate and prevent direct contact with the cylindrical battery shell, thereby posing a short circuit risk.
[0059] Example 2
[0060] The difference between this embodiment and the first embodiment is that the multiple tabs in the outer tab region 130 have different heights, and the multiple tabs in the inner tab region 110 have different heights.
[0061] Specifically, in the direction from the center of the battery cell body 100 to the outside (that is, the direction in which the central axis of the battery cell body 100 points to the edge), the height of the pole lug 200 in the outer ring pole lug area 130 gradually increases, that is, among the multiple pole lugs 200 in the outer ring pole lug area 130, the closer the pole lug 200 is to the edge of the battery cell body 100, the greater the height, and the pole lug 200 close to the middle pole lug area 120 is the smallest. In this way, the pole lug 200 close to the edge of the battery cell body 100 can have a larger area, which can further increase the flow area of the battery cell, while the pole lug 200 close to the middle pole lug area 120 is smaller in height to avoid the situation where it extends to the inner ring pole lug area 110 after bending, and can further ensure the flatness of the surface of the pole lug 200 after being flattened.
[0062] For example, in the direction from the center of the battery cell body 100 to the outside (i.e., the direction from the center axis of the battery cell body 100 to the edge), the height of the tab 200 in the inner ring tab area 110 gradually decreases, that is, among the multiple tabs 200 in the inner ring tab area 110, the tab 200 closer to the center axis of the battery cell body 100 has a greater height, and the tab 200 close to the middle tab area 120 has the smallest height. In this way, the tab 200 close to the center axis can have a larger area to further increase the flow area of the battery cell, while the tab 200 close to the middle tab area 120 has a smaller height to avoid the situation where it bends and extends to the outer ring tab area 130.
[0063] Further optionally, in the direction outward from the center of the battery cell body 100, when the height of the pole lug 200 of the outer ring pole lug area 130 gradually increases and the height of the pole lug 200 of the inner ring pole lug area 110 gradually decreases, the height of the pole lug 200 of the middle pole lug area 120 is consistent, and the difference between the height of the pole lug 200 of the middle pole lug area 120 and the minimum height of the pole lug 200 of the outer ring pole lug area 130 or the inner ring pole lug area 110 is 1mm-2mm; that is, the height of the pole lug 200 of the middle pole lug area 120 is less than that of the pole lug 200 of the outer ring pole lug area 130. The minimum height of the lug 200 is 1mm-2mm, or the height of the lug 200 in the middle lug area 120 is less than the minimum height of the lug 200 in the inner ring lug area 110 by 1mm-2mm; that is, the height of the lug 200 in the middle lug area 120 is 1mm-2mm smaller than the height of the lug 200 closest to the middle lug area 120 in the outer ring lug area 130, or the height of the lug 200 in the middle lug area 120 is 1mm-2mm smaller than the height of the lug 200 closest to the middle lug area 120 in the inner ring lug area 110.
[0064] It should be noted that if the difference between the height of the tab 200 in the middle tab region 120 and the minimum height of the tab 200 in the outer tab region 130 or the inner tab region 110 is too large, the tabs 200 in the inner tab region 110 may interfere with the tabs 200 in the outer tab region 130, thereby increasing the stacking height. If the difference between the height of the tab 200 in the middle tab region 120 and the minimum height of the tab 200 in the outer tab region 130 or the inner tab region 110 is too small, the area of the tab 200 in the outer tab region 130 or the inner tab region 110 may be small, which is not conducive to increasing the flow area. For example, the difference between the height of the tab 200 in the middle tab region 120 and the minimum height of the tab 200 in the outer tab region 130 or the inner tab region 110 is 1 mm, 1.5 mm, 1.8 mm, or 2 mm.
[0065] The other structures and features of this embodiment are similar to the corresponding structures and features in the first embodiment and have similar beneficial effects, and will not be described in detail here.
[0066] In a second aspect, this embodiment further provides a cylindrical battery, comprising the battery cell according to the first aspect. The cylindrical battery provided in this embodiment can have a larger flow area, and has improved thermal stability and safety performance.
[0067] Optionally, the cylindrical battery further comprises a housing (not shown in the figure), a busbar (not shown in the figure), and a bottom cover (not shown in the figure). The bottom cover is sealed to the open end of the housing to form a relatively sealed space with the housing, and the battery cell is located within the housing. The housing is provided with a pole, which is used to electrically connect to the negative busbar of the battery cell.
[0068] When assembling a cylindrical battery, after obtaining the battery cell described in the first aspect, the casing is placed over the battery cell, with the positive electrode tab 240 of the battery cell facing the bottom of the casing and the negative electrode tab 250 facing the top of the casing. The pole is located at the top of the casing. Next, the negative electrode busbar is connected to the pole at the top of the casing using torque welding, securing the battery cell within the casing and providing electrical connection to the casing. The bottom cover is then welded to the bottom of the casing, completing the seal and welding, thus completing the entire assembly process.
[0069] In a third aspect, this embodiment further provides an electrical device, comprising the battery cell according to the first aspect, or the cylindrical battery according to the second aspect. The electrical device provided by this embodiment has high safety performance.
[0070] Exemplarily, electrical devices include but are not limited to: mobile phones, portable devices, laptops, electric vehicles, electric cars, electric vehicles, ships, spacecraft, electric toys and electric tools, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting power tools, grinding power tools, assembly power tools and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers.
[0071] Obviously, the above-described embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the manner in which the present invention is to be implemented. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.
Claims
1. A battery cell, characterized in that: include: A battery cell body (100), the battery cell body (100) comprising a multi-layer wound pole piece; A plurality of pole tabs (200) are provided, and each layer of the pole piece is provided with at least one pole tab (200); The tab (200) is located on the end face of the battery cell body (100), and the end face of the battery cell body (100) includes an inner ring tab region (110), an intermediate tab region (120), and an outer ring tab region (130) arranged in sequence from the inside to the outside along the radial direction of the battery cell body (100); the height of the tab (200) in the intermediate tab region (120) is smaller than the height of the tab (200) in the inner ring tab region (110), and smaller than the height of the tab (200) in the outer ring tab region (130); the tab (200) in the inner ring tab region (110) is bent away from the central axis of the battery cell body (100), and the tab (200) in the outer ring tab region (130) is bent toward the central axis of the battery cell body (100).
2. The battery cell according to claim 1, characterized in that The tabs (200) in the inner ring tab region (110) have the same height, and the height difference between the tabs (200) in the middle tab region (120) and the tabs (200) in the inner ring tab region (110) is 2 mm to 3 mm; and / or, The heights of the tabs (200) in the outer ring tab region (130) are consistent, and the height difference between the tabs (200) in the middle tab region (120) and the tabs (200) in the outer ring tab region (130) is 2 mm to 3 mm.
3. The battery cell according to claim 1, characterized in that In the direction outward from the center of the battery cell body (100), the height of the tab (200) in the outer ring tab area (130) gradually increases; and / or, in the direction outward from the center of the battery cell body (100), the height of the tab (200) in the inner ring tab area (110) gradually decreases.
4. The battery cell according to claim 3, characterized in that The difference between the height of the tab (200) in the middle tab region (120) and the minimum height of the tab (200) in the outer ring tab region (130) or the inner ring tab region (110) is 1 mm to 2 mm.
5. The battery cell according to claim 1, characterized in that The number of layers of the pole pieces in the inner ring tab region (110) is N, the number of layers of the pole pieces in the middle tab region (120) is N-1.5N, and the number of layers of the pole pieces in the outer ring tab region (130) is N-1.5N.
6. The battery cell according to claim 1, characterized in that The tabs (200) of the inner ring tab region (110) and the tabs (200) of the outer ring tab region (130) cooperate with each other and cover the middle tab region (120).
7. The battery cell according to claim 6, characterized in that In the outer ring tab region (130), the number of layers of the tabs (200) covering the middle tab region (120) is 15-50; and / or In the inner ring tab region (110), the number of layers of the tabs (200) covering the middle tab region (120) is 15-50.
8. The battery cell according to any one of claims 1 to 7, characterized in that: The tab (200) of the inner ring tab region (110) comprises a first lead-out portion (211), wherein one end of the first lead-out portion (211) away from the battery cell body (100) is bent away from the central axis of the battery cell body (100) to form a first bent portion (212); The tab (200) in the middle tab region (120) includes a second lead-out portion (221); The tab (200) of the outer ring tab region (130) includes a third lead-out portion (231), and one end of the third lead-out portion (231) away from the battery cell body (100) is bent toward the central axis of the battery cell body (100) to form a second bent portion (232).
9. Cylindrical battery, characterized in that Comprising the battery cell according to any one of claims 1 to 8.
10. An electrical device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 8, or the cylindrical battery according to claim 9.