Battery cell, battery module and battery pack

Abstract

The utility model relates to the technical field of energy storage devices, in particular to a battery cell, a battery module and a battery pack, and the battery cell comprises a current collector and a plurality of layers of tabs. A plurality of layers of tabs are gathered together to form a tab group, a hollow part is formed in a welding area of the current collector, the tab group is connected with the welding area in a cold pressure welding manner so as to conduct the tab group and the current collector, and the tab group is partially embedded into the hollow part. The hollow welding areas of the tab group and the current collector are connected through the cold pressing welding process, so that the metallurgical effect is achieved, the contact resistance can be effectively reduced, the mechanical strength and toughness of the connection position between the tab group and the current collector are enhanced, and the structural stability is improved. The battery module comprises a plurality of battery cells which are connected in series or in parallel. The battery pack comprises a battery box and the battery module, wherein the battery module is arranged in the battery box. According to the battery module and the battery pack, the contact resistance between the current collector of the battery cell and the tab group can be reduced, and the structural stability at the position is enhanced.

Description

Technical Field

[0001] This utility model relates to the field of energy storage device technology, and in particular to a battery cell, battery module and battery pack. Background Technology

[0002] The tabs on the battery cell's electrodes are typically electrically connected to the outside world via a current collector. In current technology, multiple layers of tabs are usually ultrasonically or laser-welded to the current collector to form the cell's conductive structure. However, due to the complexity of the welding process and the instability of the welding quality, high contact resistance may exist at the welded locations. Furthermore, the welded locations are prone to deformation or breakage under high temperature or high load conditions, affecting battery performance. Utility Model Content

[0003] The purpose of this invention is to provide a battery cell, battery module, and battery pack that can reduce contact resistance and enhance structural stability.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A battery cell is provided, comprising:

[0006] Multi-layered tabs, wherein the multiple layers of tabs are aggregated into a tab group;

[0007] The current collector has a hollowed-out welding area. The electrode assembly is cold-press-welded to the welding area to conduct electricity between the electrode assembly and the current collector, and the electrode assembly is partially embedded in the hollowed-out area.

[0008] Optionally, the cutout includes a first cutout and a plurality of second cutouts, with the plurality of second cutouts arranged around the first cutout.

[0009] Optionally, any two second cutouts are spaced apart.

[0010] Optionally, the first perforation is a strip-shaped perforation extending along a first direction, and the welding area is located at one end of the current collector along a second direction, wherein the first direction is perpendicular to the second direction.

[0011] Optionally, the edge of the hollowed-out sidewall near one end of the tab assembly is a transitional curved surface.

[0012] Optionally, the welding area has the cutout along a third direction, and the welding area includes a first end face and a second end face that are arranged opposite to each other along the third direction. The first end face faces the electrode assembly, and the angle between the sidewall of the cutout and the first end face is an obtuse angle.

[0013] Optionally, the material of the tab assembly is the same as the material of the current collector.

[0014] Optionally, the device includes an electrode assembly, with tabs at both ends of the electrode assembly, and two current collectors are cold-pressed onto the two tab assemblies respectively.

[0015] A battery module is provided, comprising a plurality of the above-described battery cells, wherein the plurality of battery cells are connected in series or in parallel.

[0016] A battery pack is provided, including a battery box and the aforementioned battery module, wherein the battery module is disposed within the battery box.

[0017] The beneficial effects of this utility model are:

[0018] This invention provides a battery cell, including a current collector and multiple layers of tabs. The multiple layers of tabs are clustered together to form a tab assembly. The welding area of ​​the current collector has a perforation. The tab assembly is cold-pressed to the welding area to conduct electricity between the tab assembly and the current collector, with a portion of the tab assembly embedded within the perforation. The cold-pressing welding process, which connects the tab assembly and the current collector through the perforated welding area, has a metallurgical effect, effectively reducing contact resistance and improving current transmission efficiency. Furthermore, compared to conventional welding processes, the cold-pressing welding process enhances the mechanical strength and toughness of the connection between the tab assembly and the current collector, improving structural stability and ensuring battery performance.

[0019] This invention also provides a battery module comprising multiple cells as described above, wherein the cells are connected in series or in parallel. This battery module can reduce the contact resistance between the current collector and the tab assembly of the cells, thereby enhancing the structural stability of the assembly.

[0020] This utility model also provides a battery pack, including a battery case and the aforementioned battery module, with the battery module disposed inside the battery case. This battery pack can reduce the contact resistance between the current collector of the battery cell and the electrode assembly, thereby enhancing the structural stability at this location. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the battery cell structure provided in an embodiment of the present invention;

[0022] Figure 2 This is a schematic diagram of the current collector structure provided in an embodiment of the present invention.

[0023] In the picture:

[0024] 1. Electrode assembly; 11. Electrode tab assembly; 2. Current collector; 21. Welding area; 211. Second end face; 201. First cutout; 202. Second cutout. Detailed Implementation

[0025] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the drawings, not all of them.

[0026] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0027] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] like Figures 1-2 As shown, the battery cell in this embodiment includes a current collector 2 and multiple layers of tabs. The multiple layers of tabs are clustered together to form a tab assembly 11. The welding area 21 of the current collector 2 has a perforation. The tab assembly 11 is cold-pressed to the welding area 21 to conduct electricity between the tab assembly 11 and the current collector 2, and part of the tab assembly 11 is embedded within the perforation. The cold-pressing welding process between the tab assembly 11 and the current collector 2 with the perforated welding area 21 has a metallurgical effect, effectively reducing contact resistance and improving current transmission efficiency. Compared to conventional welding processes, the cold-pressing welding process enhances the mechanical strength and toughness of the connection between the tab assembly 11 and the current collector 2, improving structural stability and ensuring battery performance.

[0029] like Figure 2As shown, optionally, the perforation includes a first perforation 201 and multiple second perforations 202, with the multiple second perforations 202 arranged around the first perforation 201. Optionally, any two second perforations 202 are spaced apart. Optionally, the first perforation 201 is a strip-shaped perforation extending along a first direction, with the welding area 21 located at one end of the current collector 2 along a second direction, the first direction being perpendicular to the second direction. The multiple second perforations 202 are arranged sequentially at intervals to form a rectangular pattern. Both the first perforation 201 and the multiple second perforations 202 are elongated and narrow. Compared to setting a single wider perforation, setting multiple narrower perforations increases the sidewall area of ​​the perforation, increasing the contact area between the current collector 2 and the tab assembly 11, thereby enhancing the structural strength at this point.

[0030] Optionally, the edge of the hollowed-out sidewall near the end of the tab assembly 11 is a transitional curved surface, which can further enhance the structural strength at the edge.

[0031] Optionally, the welding area 21 has a hollowed-out section along a third direction. The welding area 21 includes a first end face and a second end face 211 arranged opposite each other along the third direction. The first end face faces the tab assembly 11, and the angle between the hollowed-out sidewall and the first end face is an obtuse angle, which facilitates the embedding of the tab assembly 11 material into the hollowed-out section. The third direction is perpendicular to both the first and second directions.

[0032] Optionally, the material of the tab assembly 11 is the same as that of the current collector 2. Optionally, in this embodiment, both the tab assembly 11 and the current collector 2 are made of aluminum. In other embodiments, the tab assembly 11 is made of copper, and the current collector 2 is made of nickel-plated copper. The use of nickel-plated copper not only improves conductivity but also enhances corrosion resistance and extends service life.

[0033] Optionally, the battery cell also includes an electrode assembly 1, with tabs 11 at both ends of the electrode assembly 1, and two current collectors 2 are cold-pressed onto the two tabs 11 respectively.

[0034] Table 1

[0035]

[0036]

[0037] Table 1 above provides ten sets of comparative battery cells and ten sets of embodiment battery cells. In the comparative battery cells, the current collector 2 and the electrode are connected by conventional laser welding process, and the current collector 2 is not hollowed out. The battery cells in the embodiments are the above-mentioned battery cells, in which the current collector 2 and the electrode group 11 are connected by cold pressing welding process, and the current collector 2 is hollowed out.

[0038] As shown in Table 1, the contact resistance of the comparative sample cells is greater than that of the sample cells, the tensile force that the comparative sample cells can withstand is less than that of the sample cells, and the residual weld area ratio of the comparative sample cells is also less than that of the sample cells. Clearly, the design of using cold-press welding and creating a perforation in the current collector 2 can significantly reduce the contact resistance of the cells, increase the structural strength of the cell connections, and improve the performance of the cells.

[0039] In existing technologies, the welding of the tabs and current collectors uses conventional ultrasonic welding or laser welding methods, which are complex and produce inconsistent quality, resulting in high contact resistance. In this embodiment, the current collector 2 has a hollow design and is cold-pressed to the tab assembly 11, achieving a metallurgical effect that effectively reduces contact resistance and improves current transmission efficiency. In existing technologies, the connection between the current collector and the tabs is prone to deformation or breakage under high temperature or high load conditions, affecting battery performance. The cold-pressing welding process in this embodiment enhances the mechanical strength and toughness of the connection, improving structural stability. The battery generates heat during charging and discharging; the hollow design of the current collector 2 in this embodiment also improves heat dissipation, helping to ensure the battery operates within a safe temperature range. Furthermore, the hollow design saves materials, reduces overall weight, and lowers costs.

[0040] This embodiment also provides a battery module, including multiple cells as described above, which are connected in series or in parallel. Optionally, the battery module further includes a busbar, with each cell electrically connected to the busbar to achieve a series-parallel design of the multiple cells.

[0041] This battery module can reduce the contact resistance between the current collector 2 of the battery cell and the tab assembly 11, thereby enhancing the structural stability at this location.

[0042] This embodiment also provides a battery pack, including a battery box and the aforementioned battery module, with the battery module disposed inside the battery box. Optionally, the battery pack may also include expansion beams, crossbeams, bottom supports, and other structures to ensure overall structural strength.

[0043] This battery pack can reduce the contact resistance between the current collector 2 of the battery cell and the tab assembly 11, thereby enhancing the structural stability at this location.

[0044] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. An electric cell, characterized by, The application relates to a multi-layer tab and a battery cell. The multi-layer tab is gathered into a tab group (11); a current collector (2) has a welding area (21) with an opening, and the tab group (11) is cold-welded with the welding area (21) to connect the tab group (11) with the current collector (2), and the tab group (11) is partially embedded in the opening. The opening comprises a first opening (201) and a plurality of second openings (202), and the plurality of second openings (202) are arranged around the first opening (201).

2. The electric cell of claim 1, wherein, Any two second openings (202) are arranged at intervals.

3. The electric cell of claim 2, wherein, The first opening (201) is a strip-shaped opening extending along a first direction, and the welding area (21) is located at one end of the current collector (2) along a second direction, and the first direction is perpendicular to the second direction.

4. The cell of claim 2, wherein, The edge of the side wall of the opening close to one end of the tab group (11) is a transition curved surface.

5. The cell of any of claims 1-4, wherein, The welding area (21) has the opening along a third direction, and the welding area (21) comprises a first end surface and a second end surface (211) oppositely arranged along the third direction, the first end surface faces the tab group (11), and the included angle between the side wall of the opening and the first end surface is an obtuse angle.

6. The cell of any of claims 1-4, wherein, The material of the tab group (11) is consistent with the material of the current collector (2).

7. The cell of any of claims 1-4, wherein, The application relates to a tab group (1), and both ends of the tab group (1) have the tab group (11), and two current collectors (2) are cold-welded with the two tab groups (11) respectively.

8. The cell of any of claims 1-4, wherein, The application relates to a plurality of battery cells as claimed in any one of claims 1-8, and the plurality of battery cells are connected in series or in parallel.

9. A battery module, characterized by The application relates to a battery box and a battery module as claimed in claim 9, and the battery module is arranged in the battery box.

10. A battery pack, characterized by, ​

Images