Battery cell, battery device, and electric device

Abstract

The application provides a battery monomer, a battery device and a power utilization device, and belongs to the technical field of batteries. The battery monomer comprises a shell, a first electrode terminal, an electrode assembly and a first current collecting member. The first electrode terminal is arranged on a wall portion of the shell. The electrode assembly is arranged in the shell and comprises a main body portion and a first tab protruding from the main body portion. The first current collecting member is arranged between the main body portion and the wall portion, and comprises a first connecting region and a second connecting region which are integrally formed. The thickness of the first connecting region is greater than that of the second connecting region. The first connecting region is connected with the first tab, and the second connecting region is welded with the first electrode terminal. A through hole is arranged on the second connecting region and penetrates through the second connecting region. This structure can reduce the risk of the components for insulation or sealing inside the battery monomer being scalded, and can facilitate the first current collecting member to run material during the process of stamping to form the second connecting region.

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, to reduce the assembly difficulty of battery cells, current collectors are usually set inside the battery cells to connect the electrode terminals of the battery cells and the tabs of the electrode assembly. However, the current collectors and electrode terminals of existing battery cells are usually assembled by welding. The welding assembly of electrode terminals and current collectors can easily cause damage to other parts of the battery cell, resulting in poor production quality of the battery cells and hindering the improvement of the stability of the battery cells in use. Utility Model Content

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

[0005] In a first aspect, embodiments of this application provide a battery cell, including a housing, a first electrode terminal, an electrode assembly, and a first current collector; the housing has a wall portion; the first electrode terminal is disposed on the wall portion; the electrode assembly is disposed within the housing, the electrode assembly includes a main body portion and a first tab, the first tab protruding from the main body portion; at least a portion of the first current collector is disposed between the main body portion and the wall portion, the first current collector includes an integrally formed first connection region and a second connection region, the thickness of the first connection region is greater than the thickness of the second connection region, the first connection region is connected to the first tab, the second connection region is welded to the first electrode terminal, and a through hole is provided on the second connection region, the through hole penetrating the second connection region.

[0006] In the above technical solution, by setting the thickness of the first connection area of ​​the first current collector for interconnection with the first electrode tab to be greater than the thickness of the second connection area of ​​the first current collector for welding with the first electrode terminal, the structure of the first current collector for welding with the first electrode terminal is thinned. This reduces the difficulty of welding the first current collector to the first electrode terminal and also reduces the power required for welding the first current collector to the first electrode terminal. This reduces the risk of the welded area of ​​the first electrode terminal being burned by excessive power, which could damage the internal insulation or sealing components of the battery cell. Consequently, it reduces the risk of insulation or sealing failure during battery cell use. To improve the stability of battery cells, through-holes are provided in the thinner second connection area. This reduces weight and increases energy density. Furthermore, when the thinner second connection area of ​​the integrally formed first current collector is formed by stamping, the through-holes provide space for material flow and compression during the stamping process. This facilitates material flow during the stamping of the second connection area, improving the stamping quality of the second connection area. Ultimately, this reduces the risk of insulation or sealing failure in battery cells while improving the processing quality of the first current collector, thus enhancing both the stability and production quality of the battery cells.

[0007] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the wall portion is rectangular, and the size of the orthographic projection of the wall portion in the first direction is larger than the size of the orthographic projection of the wall portion in the second direction. The thickness direction of the wall portion, the first direction, and the second direction are perpendicular to each other. The first current collection member includes two first connection areas, and along the first direction, the two first connection areas are respectively connected to the two ends of the second connection area.

[0008] In the above technical solution, by connecting the first connection area to both ends of the second connection area along the length of the wall, the areas of the first current collector on both sides of the first electrode terminal in the first direction can be connected to the first tab. On the one hand, this can increase the area and area of ​​the first current collector for connecting to the first tab. On the other hand, it can adjust the connection position between the first tab and the first current collector according to the actual situation, which is beneficial to improving the production flexibility of the battery cell.

[0009] In some embodiments, the thickness of the first connection region is D1 and the thickness of the second connection region is D2, satisfying that 0.1mm≤D1-D2≤1mm.

[0010] In the above technical solution, on the one hand, the thickness difference between the first connection area and the second connection area is set to be greater than or equal to 0.1 mm to improve the thinning effect of the second connection area. This further reduces the difficulty of welding and assembling the first current collector and the first electrode terminal, and also further reduces the power required for welding the first current collector and the first electrode terminal. This further reduces the risk of the welded area of ​​the first electrode terminal being burned by excessive power, which could damage the internal insulation or sealing components of the battery cell. On the other hand, setting the thickness difference between the first connection area and the second connection area to be less than or equal to 1 mm can alleviate the phenomenon of excessive thickness difference between the first connection area and the second connection area. This can effectively reduce the manufacturing and forming difficulty of the first current collector. Moreover, when the second connection area is stamped, it can effectively reduce the material flow of the first current collector during the stamping process, which is conducive to further improving the stamping quality of the second connection area of ​​the first current collector.

[0011] In some embodiments, the first electrode terminal has a connection surface facing the second connection area in the thickness direction of the wall portion, and the connection surface is welded to the second connection area; in a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the hole wall surface of the through hole is located within the orthographic projection of the connection surface.

[0012] In the above technical solution, by setting at least a portion of the orthographic projection of the hole wall surface in the projection plane perpendicular to the thickness direction of the wall to be located within the orthographic projection of the connection surface of the first electrode terminal in the projection plane perpendicular to the thickness direction of the wall, the connection surface of the first electrode terminal for welding with the second connection area is a structure that corresponds to at least a portion of the through hole in the thickness direction of the wall. This facilitates heat dissipation during the welding and assembly of the first electrode terminal and the second connection area, and the through hole also enables welding positioning between the first electrode terminal and the second connection area, which is beneficial to improving the welding quality between the first electrode terminal and the second connection area. On the other hand, it enables the first electrode terminal to cover at least a portion of the through hole, thereby reducing the impact of the through hole on the flow area in the flow path between the first electrode terminal and the first connection area.

[0013] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall portion, the entire orthographic projection of the hole wall surface of the through hole lies within the orthographic projection of the connecting surface.

[0014] In the above technical solution, by setting the entire orthographic projection of the hole wall surface in the projection plane perpendicular to the thickness direction of the wall to be located within the orthographic projection of the connection surface of the first electrode terminal in the projection plane perpendicular to the thickness direction of the wall, the connection surface of the first electrode terminal for welding with the second connection area is a structure that covers the through hole in the thickness direction of the wall. This facilitates the welding assembly of the first electrode terminal and the second connection area, and further facilitates heat dissipation during the welding assembly of the first electrode terminal and the second connection area, which is beneficial to further improve the welding quality between the first electrode terminal and the second connection area. On the other hand, it enables the first electrode terminal to have a structure that covers the through hole, so that the welding area of ​​the first electrode terminal and the second connection area is located on the outer periphery of the through hole, thereby further reducing the impact of the through hole on the flow area in the flow path between the first electrode terminal and the first connection area.

[0015] In some embodiments, the second connection area and the first electrode terminal are welded together to form a first solder mark on the second connection area, the first solder mark being located on the outer peripheral side of the through hole and extending circumferentially along the through hole.

[0016] In the above technical solution, by setting the first solder mark on the second connection area as a structure located on the outer periphery of the through hole and extending circumferentially along the through hole, the regularity of the welding area between the second connection area and the first electrode terminal is improved. On the one hand, the welding difficulty of the first electrode terminal and the second connection area can be reduced, and heat dissipation through the through hole is facilitated when the first electrode terminal and the second connection area are welded and assembled together. On the other hand, the welding reliability between the first electrode terminal and the second connection area can be improved, and the influence of the through hole on the flow area on the flow path between the first electrode terminal and the first connection area can be reduced.

[0017] In some embodiments, the first solder mark is an annular structure surrounding the through hole.

[0018] In the above technical solution, by setting the first solder mark as an annular structure surrounding the through hole, the first solder mark is a continuous structure with the first and last parts connected. This can improve the welding efficiency of the first electrode terminal and the second connection area, thereby increasing the production efficiency of the battery cell. On the other hand, it can increase the welding area between the first electrode terminal and the second connection area, thereby increasing the current flow area between the first electrode terminal and the second connection area, and improving the connection reliability between the first electrode terminal and the second connection area.

[0019] In some embodiments, the first solder mark is spaced apart at both ends of the through hole in the circumferential direction.

[0020] In the above technical solution, by setting the first solder mark to be arranged at intervals at both ends of the through hole in the circumferential direction, the first solder mark is not connected at the beginning and end of the through hole in the circumferential direction. This can reduce the welding difficulty between the first electrode terminal and the second connection area, reduce the influence of the welding pool at the beginning and end of the first solder mark in the circumferential direction of the through hole, and alleviate the phenomenon of excessive temperature caused by the first solder mark being continuously welded at the beginning and end of the through hole in the circumferential direction, thereby improving the welding quality of the first electrode terminal and the second connection area.

[0021] In some embodiments, the first solder mark includes a plurality of sub-solder marks, which are arranged at circumferential intervals along the through hole.

[0022] In the above technical solution, by setting the first solder mark portion to include a plurality of sub-solder marks arranged circumferentially along the through hole, the first solder mark is a structure that is intermittently welded and discontinuous in the circumferential direction of the through hole. This structure can reduce the welding time of the first electrode terminal and the second connection area in a single welding process, thereby alleviating the phenomenon of excessively high temperature caused by the continuous welding of the first solder mark portion. This is beneficial to improving the welding quality of the first electrode terminal and the second connection area, and also beneficial to reducing the range of the heat-affected zone caused by welding on the first electrode terminal and the second connection area.

[0023] In some embodiments, there are multiple first solder marks, and the multiple first solder marks are arranged at intervals in the radial direction of the through hole.

[0024] In the above technical solution, by forming a plurality of first solder marks arranged radially and spaced apart along the through hole on the second connection area, it is beneficial to further increase the welding area between the first electrode terminal and the second connection area, thereby increasing the current flow area between the first electrode terminal and the second connection area, and further improving the connection reliability between the first electrode terminal and the second connection area.

[0025] In some embodiments, the second connection area and the first electrode terminal are welded together to form a first solder mark on the second connection area; the first solder mark includes a plurality of solder marks and at least one solder mark transition portion, the solder marks extend circumferentially along the through hole, and the solder marks have opposing first ends and second ends in the circumferential direction of the through hole, the plurality of solder marks are arranged radially spaced along the through hole, and in two adjacent solder marks, the solder mark transition portion connects the first end of one solder mark and the second end of the other solder mark.

[0026] In the above technical solution, multiple solder bodies of the first soldering part are arranged at intervals in the radial direction of the through hole. In two adjacent solder bodies, each solder transition part connects the first end of one solder body and the second end of the other solder body, so that the first soldering part presents a spiral structure surrounding the through hole. This enables the first soldering part to have a continuous structure that surrounds the through hole multiple times, thereby increasing the welding area between the first electrode terminal and the second connection area while improving the welding efficiency of the first electrode terminal and the second connection area.

[0027] In some embodiments, the second connection area and the first electrode terminal are welded together to form a first solder mark on the second connection area, and the minimum distance between the first solder mark and the first connection area is L, which satisfies 2mm≤L≤8mm.

[0028] In the above technical solution, on the one hand, the minimum distance between the first solder mark formed on the second connection area and the first connection area is set to be greater than or equal to 2mm, so as to reduce the phenomenon that the welding position of the first electrode terminal and the second connection area is too close to the first connection area, which is beneficial to reduce the welding difficulty of the first electrode terminal and the second connection area and can optimize the welding process of the first electrode terminal and the second connection area. On the other hand, the minimum distance between the first solder mark formed on the second connection area and the first connection area is set to be less than or equal to 8mm, so as to shorten the current conduction path between the first solder mark and the first connection area, thereby reducing the impact of the thinned second connection area on the current flow area between the first electrode terminal and the first connection area, and reducing the current transmission resistance between the first electrode terminal and the first connection area, so as to reduce the local temperature rise phenomenon of the first current collector during use.

[0029] In some embodiments, the Vickers hardness of the second connection region is greater than that of the first connection region.

[0030] In the above technical solution, by setting the Vickers hardness of the thinner second connection area in the first current collector to be greater than that of the thicker first connection area in the first current collector, the structure of the first current collector forming the first connection area and the second connection area with different thicknesses is formed by stamping. The first current collector with this structure can reduce the forming difficulty of the first current collector, thereby reducing the manufacturing difficulty of the first current collector. On the other hand, it can effectively improve the structural strength of the thinned second connection area of ​​the first current collector, thereby reducing the risk of deformation or cracking of the second connection area during use.

[0031] In some embodiments, in a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the wall portion is rectangular, and the size of the orthographic projection of the wall portion in the first direction is greater than the size of the orthographic projection of the wall portion in the second direction. The thickness direction of the wall portion, the first direction, and the second direction are perpendicular to each other. The first connecting area and the second connecting area are arranged along the second direction, and both the first connecting area and the second connecting area extend along the first direction.

[0032] In the above technical solution, by setting the first connection area and the second connection area to be arranged along the width direction of the wall and extending along the length direction of the wall, it is beneficial to increase the area of ​​the first connection area and the second connection area, and to reduce the difficulty of forming the first connection area and the second connection area with different thicknesses in the first current collector, so as to reduce the manufacturing difficulty of the first current collector.

[0033] In some embodiments, the battery cell includes two first current collectors arranged along the thickness direction of the wall, the two first current collectors being stacked and connected; along the thickness direction of the wall, a portion of the first tab is located between the two first current collectors.

[0034] In the above technical solution, the battery cell is provided with two first current collectors that are welded to the first electrode terminal. The two first current collectors are stacked and connected along the thickness direction of the wall. By setting the first tab part to be located between the two first current collectors, the two first current collectors can also play a certain clamping role on the first tab, which is conducive to further improving the connection stability between the first tab and the first current collector.

[0035] In some embodiments, along the thickness direction of the wall, the second connection regions of the two first current collectors are stacked and connected, and the first connection regions of the two first current collectors are arranged at intervals; a portion of the first tab is located between the first connection regions of the two first current collectors and is connected to the first connection regions of the two first current collectors.

[0036] In the above technical solution, by setting the first connection areas of the two first current collectors to be arranged at intervals along the thickness direction of the wall, and setting the first tab to be located between and connected to the first connection areas of the two first current collectors, the first connection areas of the two first current collectors are configured to clamp and connect to the first tab. The battery cell with this structure can reduce the risk of cracking of the first tab during use and assembly, and is conducive to improving the connection quality and reliability between the first tab and the first current collector.

[0037] In some embodiments, at least one of the first current collectors is bent to form a bending region, and the bending region connects the first connection region and the second connection region.

[0038] In the above technical solution, at least one first current collector is bent to form a bending area, and the bending area is a structure that connects the first connection area and the second connection area of ​​the corresponding first current collector, so as to realize that the two first current collectors are arranged at intervals along the thickness direction of the wall and clamp the first electrode ear. The structure is simple and easy to implement.

[0039] In some embodiments, the through holes on the second connection areas of the two first current collectors are interconnected.

[0040] In the above technical solution, by setting the through holes on the second connection area of ​​the two first current collectors to be interconnected, the through holes on the second connection area of ​​the two first current collectors are arranged in a corresponding manner in the thickness direction of the wall, thereby reducing the difficulty of avoiding the through holes when the two stacked and connected first current collectors are welded to the first electrode terminal, thus reducing the assembly difficulty of the battery cell.

[0041] In some embodiments, the orthographic projections of the hole walls of the through holes on the second connection areas of the two first current collectors overlap in a projection plane perpendicular to the thickness direction of the wall.

[0042] In the above technical solution, by setting the through holes on the second connection area of ​​the two first current collectors to be completely overlapping, on the one hand, it is possible to first stack the two first current collectors and connect them, and then process the through holes in the same way, which is beneficial to optimize the production cycle and improve the production efficiency of the battery cell. On the other hand, it can further reduce the difficulty of avoiding the through holes when the two stacked and connected first current collectors are welded to the first electrode terminal, so as to further reduce the assembly difficulty of the battery cell.

[0043] In some embodiments, the first electrode terminal has a connecting surface facing the second connecting region in the thickness direction of the wall portion, the connecting surface being welded to the second connecting region, and at least a portion of the orthographic projection of the connecting surface and at least a portion of the orthographic projection of the first connecting region overlapping in a projection plane perpendicular to the thickness direction of the wall portion; along the thickness direction of the wall portion, the first connecting region has a first surface facing the first electrode terminal and a second surface facing away from the first electrode terminal, the first surface being connected to the connecting surface, and the second connecting region has a third surface facing the first electrode terminal and a fourth surface facing away from the first electrode terminal, the first surface and the third surface being flush, and the second surface being closer to the main body portion than the fourth surface.

[0044] In the above technical solution, at least a portion of the orthographic projection of the connecting surface and at least a portion of the orthographic projection of the first connecting area overlap in the projection plane perpendicular to the thickness direction of the wall, so that the first electrode terminal and the first connecting area have an overlapping area in the thickness direction of the wall, so that the first electrode terminal and the first connecting area can share a portion of space in the direction perpendicular to the thickness direction of the wall. In this case, by setting the first surface of the first connecting area facing the first electrode terminal and the third surface of the second connecting area facing the first electrode terminal as flush and coplanar, and setting the second surface of the first connecting area away from the first electrode terminal as closer to the main body than the fourth surface of the second connecting area away from the first electrode terminal, the first connecting area is a structure that protrudes from the side of the second connecting area away from the first electrode terminal and is flush with the side of the second connecting area facing the first electrode terminal. This reduces the interference caused by the welding assembly of the first connecting area to the connecting surface of the first electrode terminal and the second connecting area when the thicknesses of the first connecting area and the second connecting area are different, which helps to reduce the welding gap between the connecting surface of the first electrode terminal and the second connecting area, thereby improving the welding quality of the first electrode terminal and the second connecting area.

[0045] In some embodiments, the first electrode terminal has a connecting surface facing the second connecting area in the thickness direction of the wall portion, the connecting surface being welded to the second connecting area, and the orthographic projection of the connecting surface and the orthographic projection of the first connecting area not overlapping in a projection plane perpendicular to the thickness direction of the wall portion; along the thickness direction of the wall portion, the first connecting area has a first surface facing the first electrode terminal and a second surface facing away from the first electrode terminal, the first surface being connected to the connecting surface, the second connecting area has a third surface facing the first electrode terminal and a fourth surface facing away from the first electrode terminal, the second surface and the fourth surface being flush, and the first surface being further away from the main body portion than the third surface.

[0046] In the above technical solution, the orthographic projection of the connecting surface and the orthographic projection of the first connecting area do not overlap in the projection plane perpendicular to the thickness direction of the wall, so that the first electrode terminal and the first connecting area do not have an overlapping area in the thickness direction of the wall. Specifically, by setting the second surface of the first connecting area away from the first electrode terminal and the fourth surface of the second connecting area away from the first electrode terminal as flush and coplanar, and setting the first surface of the first connecting area facing the first electrode terminal as being further away from the main body than the third surface of the second connecting area facing the first electrode terminal, the first connecting area is made to protrude from the side of the second connecting area facing the first electrode terminal and be flush with the side of the second connecting area away from the first electrode terminal. After the connecting surface of the first electrode terminal and the second connecting area are welded together, the first surface of the first connecting area facing the first electrode terminal is further away from the main body than the connecting surface. Thus, even when the thicknesses of the first connecting area and the second connecting area are different, the first connecting area of ​​the first current collector and the first electrode terminal can share a portion of the space in the thickness direction of the wall, which is beneficial to optimizing the internal space utilization of the battery cell and improving the energy density of the battery cell.

[0047] In some embodiments, the first connection area and the first electrode tab are welded together.

[0048] In the above technical solution, by setting the first connection area and the first electrode of the first current collector to a welded connection structure, the connection stability and reliability between the first connection area and the first electrode can be improved, and the current flow performance between the first connection area and the first electrode can be improved.

[0049] In some embodiments, the first electrode terminal has a connection portion located on the side of the wall facing the electrode assembly in the thickness direction of the wall portion, and the connection portion is welded to the second connection area and a second solder mark is formed on the connection portion; the battery cell further includes an insulating component, at least a portion of which is located between the connection portion and the wall portion in the thickness direction of the wall portion to insulate the connection portion and the wall portion, and in a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the insulating component overlaps with the orthographic projection of the second solder mark.

[0050] In the above technical solution, by providing an insulating component between the connection portion and the wall portion of the first electrode terminal, the insulating component can insulate and isolate the connection portion and the wall portion, thereby reducing the risk of short circuit between the first electrode terminal and the wall portion. Specifically, by setting the orthographic projection of the insulating component in the projection plane perpendicular to the thickness direction of the wall portion to at least partially overlap with the orthographic projection of the second solder in the projection plane perpendicular to the thickness direction of the wall portion, and since the first current collector is a structure in which the area to be welded to the first electrode terminal is thinned, the phenomenon of burning or damaging the insulating component in the area to be welded to the first electrode terminal can be alleviated by reducing the power required for the first current collector to be welded to the first electrode terminal. This reduces the risk of insulation failure in the battery cell during use and is beneficial to improving the stability and reliability of the battery cell.

[0051] Secondly, embodiments of this application also provide a battery device, including the aforementioned battery cell.

[0052] 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

[0053] 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.

[0054] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0055] Figure 2 Exploded views of the structure of the battery device provided in some embodiments of this application;

[0056] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0057] Figure 4 Exploded views of the structure of a single battery cell provided in some embodiments of this application;

[0058] Figure 5 Partial cross-sectional view of a battery cell provided in some embodiments of this application;

[0059] Figure 6 A cross-sectional view of the first current collector of a battery cell provided in some embodiments of this application;

[0060] Figure 7A partial cross-sectional view of a battery cell provided for further embodiments of this application;

[0061] Figure 8 A cross-sectional view of the first current collector of a battery cell provided in some further embodiments of this application;

[0062] Figure 9 A front view of the first current collector of a battery cell provided in some embodiments of this application in the thickness direction of the wall portion;

[0063] Figure 10 A front view of the first current collector of a battery cell in the thickness direction of the wall portion, provided in some embodiments of this application;

[0064] Figure 11 A front view of the first current collector of a battery cell in the thickness direction of the wall portion, provided in some embodiments of this application;

[0065] Figure 12 A front view of the first current collector of a battery cell provided in another embodiment of this application in the thickness direction of the wall portion;

[0066] Figure 13 A partial cross-sectional view of a battery cell provided for some other embodiments of this application;

[0067] Figure 14 A schematic diagram of the assembly of two first current collectors of a battery cell provided in some other embodiments of this application;

[0068] Figure 15 Cross-sectional views of two first current collectors of a battery cell provided in some other embodiments of this application.

[0069] Icons: 1000 - Vehicle; 100 - Battery assembly; 10 - Housing; 11 - First housing body; 12 - Second housing body; 20 - Battery cell; 21 - Housing; 211 - Wall; 212 - Housing; 2121 - Opening; 213 - End cap; 22 - First electrode terminal; 221 - Connecting surface; 222 - Connecting part; 23 - Electrode assembly; 231 - Main body; 232 - First tab; 233 - Second tab; 24 - First current collector; 241 - First connection area; 2411 - First surface; 2412 - Second surface; 242 - Second connection area; 2421 - Through hole; 2422 - Third surface; 2423 - Fourth surface; 243 - Bending area; 244 - Accommodation space; 25 - Second electrode terminal; 26 - Second current collector; 27 - Pressure relief component; 28 - Solder stamp; 281 - First solder stamp; 2811 - Sub-solder stamp; 2812 - Solder stamp body; 2812a - First end; 2812b - Second end; 2813 - Solder stamp transition; 282 - Second solder stamp; 29 - Insulating component; 291 - Insulating element; 292 - Sealing element; 200 - Controller; 300 - Motor; X - Thickness direction of the wall; Y - First direction; Z - Second direction. Detailed Implementation

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] In this application, "multiple" means two or more (including two).

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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, 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.).

[0083] 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.

[0084] 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.

[0085] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0086] 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 electrodes, or titanium, etc. Foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, 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 alloys, nickel, nickel alloys, titanium, titanium alloys, silver and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0087] 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.

[0088] 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.

[0089] 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.

[0090] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0091] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0099] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0100] 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.

[0101] 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.

[0102] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0103] In some implementations, the electrode assembly has a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0104] In some implementations, the electrode assembly has a stacked structure.

[0105] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0106] 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.

[0107] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0108] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0109] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0110] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0111] In some embodiments, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0118] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] For a typical battery cell, it includes a casing, electrode assembly, and electrode terminals mounted on the casing. To reduce the assembly difficulty of the battery cell, a current collector is usually placed inside the casing. The current collector connects the electrode terminals and the tabs of the electrode assembly, thus reducing the assembly difficulty between the electrode tabs and the electrode terminals. To further reduce the connection difficulty between the current collector and the electrode terminals, welding is usually used to achieve the connection between the current collector and the electrode terminals, such as laser welding. However, existing battery cells have insulating and sealing components between the electrode terminals and the casing. The insulating components provide insulation and the sealing components seal the gap between the electrode terminals and the casing. When welding the current collector and the electrode terminals, the welded area of ​​the electrode terminals can easily burn the insulating and sealing components, leading to risks such as insulation failure or sealing failure between the electrode terminals and the casing. This results in poor production quality of the battery cell and is not conducive to improving the stability of the battery cell in use.

[0125] Based on the above considerations, in order to solve the problems of poor production quality and low stability in use of battery cells, this application provides a battery cell including a casing, a first electrode terminal, an electrode assembly, and a first current collector. The casing has a wall portion. The first electrode terminal is disposed in the wall portion. The electrode assembly is disposed inside the casing, and the electrode assembly includes a main body portion and a first tab, the first tab protruding from the main body portion. At least a portion of the first current collector is disposed between the main body portion and the wall portion. The first current collector includes an integrally formed first connection region and a second connection region. The thickness of the first connection region is greater than the thickness of the second connection region. The first connection region is connected to the first tab, and the second connection region is welded to the first electrode terminal. A through hole is provided on the second connection region, the through hole penetrating the second connection region.

[0126] In this type of battery cell, by setting the thickness of the first connection area of ​​the first current collector for interconnection with the first electrode tab to be greater than the thickness of the second connection area of ​​the first current collector for welding with the first electrode terminal, the area of ​​the first current collector for welding with the first electrode terminal is thinned. This reduces the difficulty of welding the first current collector to the first electrode terminal and also reduces the power required for welding. This reduces the risk of the welded area of ​​the first electrode terminal being burned by excessive power, which could damage the internal insulation or sealing components of the battery cell. Consequently, it reduces the likelihood of insulation or sealing failures during battery cell use. To mitigate risks and improve the stability of battery cells, through-holes are provided in the thinner second connection area. This reduces weight and increases energy density. Furthermore, when the thinner second connection area of ​​the integrally formed first current collector is formed by stamping, the through-holes provide space for material flow and compression during the stamping process. This facilitates material flow during the stamping of the second connection area, improving the stamping quality of the second connection area. Ultimately, this reduces the risk of insulation or sealing failure in battery cells while improving the processing quality of the first current collector, thus enhancing both the stability and production quality of the battery cells.

[0127] 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 for such an electrical device can be constructed using battery cells and battery devices disclosed in this application. This helps to mitigate the problem of damage to other components during welding and assembly of current collectors and electrode terminals, thereby improving the production quality and operational stability of the battery cells.

[0128] 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.

[0129] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device according to an embodiment of this application.

[0130] Please refer to Figure 1 , Figure 1This 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] According to some embodiments of this application, refer to Figure 3 Please refer to further details. Figure 4 , Figure 5 and Figure 6 , 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 partial cross-sectional view of a battery cell 20 provided in some embodiments of this application. Figure 6This is a cross-sectional view of the first current collector 24 of a battery cell 20 provided in some embodiments of this application. This application provides a battery cell 20, which includes a housing 21, a first electrode terminal 22, an electrode assembly 23, and a first current collector 24. The housing 21 has a wall portion 211. The first electrode terminal 22 is disposed on the wall portion 211. The electrode assembly 23 is disposed within the housing 21, and the electrode assembly 23 includes a main body portion 231 and a first tab 232, the first tab 232 protruding from the main body portion 231. At least a portion of the first current collector 24 is disposed between the main body 231 and the wall 211. The first current collector 24 includes an integrally formed first connection area 241 and a second connection area 242. The thickness of the first connection area 241 is greater than the thickness of the second connection area 242. The first connection area 241 is connected to the first electrode tab 232, and the second connection area 242 is welded to the first electrode terminal 22. A through hole 2421 is provided on the second connection area 242, and the through hole 2421 penetrates the second connection area 242.

[0139] 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 or a cuboid. Similarly, the outer shell 21 can be made of various materials, such as copper, iron, aluminum, steel, or aluminum alloy.

[0140] In some embodiments, the housing 21 may include a housing 212 and an end cap 213. The housing 212 has an internal cavity for accommodating the electrode assembly 23 and has an opening 2121. That is, the housing 212 is a hollow structure with at least one end opening 2121. The end cap 213 covers the opening 2121 of the housing 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 23 and the electrolyte.

[0141] For example, in Figure 3 and Figure 4 In the process, the outer casing 21 may include a housing 212 and two end caps 213. The housing 212 is a hollow structure with openings 2121 on opposite sides. One end cap 213 is fitted onto one opening 2121 of the housing 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 23 and the electrolyte. That is, the housing 212 has openings 2121 on opposite sides, and the two end caps 213 are fitted onto the opposite sides of the housing 212 to close the corresponding openings 2121.

[0142] It should be noted that the wall portion 211 for mounting the first electrode terminal 22 can be the end cap 213 of the housing 21, or it can be a wall of the housing 212 of the housing 21. For example, in... Figure 3 and Figure 4 In the middle, the wall portion 211 is one of the two end caps 213 of the outer shell 21.

[0143] The housing 212 can have various shapes, such as a cylinder, cuboid, or prism. The shape of the housing 212 can be determined based on the specific shape of the electrode assembly 23. For example, if the electrode assembly 23 is a cylinder, a cylindrical housing 212 can be used; if the electrode assembly 23 is a cuboid, a cuboid housing 212 can be used. Of course, the end cap 213 can also have various structures, such as a plate-like structure or a hollow structure open at one end. For example, in… Figure 3 In the middle, the shell 212 has a cuboid structure, and correspondingly, the end cap 213 has a rectangular plate structure.

[0144] Of course, it is understandable that the housing 21 is not limited to the structure described above. In some embodiments, the housing 212 may also be a hollow structure with only one side opening 2121. Correspondingly, the housing 21 includes only one end cap 213. That is, the housing 212 includes a bottom wall and a side wall. The bottom wall and the end cap 213 are disposed opposite to each other. The side wall surrounds the bottom wall, and one end of the side wall is connected to the bottom wall, while the other end is closed to form the opening 2121. The end cap 213 is connected to the side wall of the housing 212 and closes the opening 2121.

[0145] In the embodiments of this application, the structure of the electrode assembly 23 can be various. For example, the electrode assembly 23 can be a wound structure formed by winding a positive electrode sheet, an insulating member and a negative electrode sheet, or a stacked structure formed by arranging a positive electrode sheet, an insulating member and a negative electrode sheet in layers.

[0146] For example, the separator 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.

[0147] The electrode assembly 23 includes a main body 231 and a first tab 232. The main body 231 is the primary component of the electrode assembly 23 for electrochemical reactions to occur in the battery cell 20. For example, in... Figure 4 In the middle, the first electrode tab 232 is connected to one end of the main body 231 facing the wall 211 in the thickness direction X of the wall. That is, in the thickness direction X of the wall, the first electrode tab 232 is located between the main body 231 and the wall 211, so that the first electrode tab 232 can be connected to the first electrode terminal 22 through the first current collector 24.

[0148] It should be noted that the first tab 232 of the electrode assembly 23 is a component formed by stacking and connecting regions of the positive electrode sheet that are not coated with a positive active material layer, or a component formed by stacking and connecting regions of the negative electrode sheet that are not coated with a negative active material layer. If the first tab 232 is the positive tab of the electrode assembly 23, then the first tab 232 is a component formed by stacking and connecting regions of the positive electrode sheet that are not coated with a positive active material layer; if the first tab 232 is the negative tab of the electrode assembly 23, then the first tab 232 is a component formed by stacking and connecting regions of the negative electrode sheet that are not coated with a negative active material layer.

[0149] exist Figure 4 In the electrode assembly 23, there is also a second electrode tab 233. The polarity of the second electrode tab 233 is opposite to that of the first electrode tab 232. That is, if the first electrode tab 232 is the positive electrode tab of the electrode assembly 23, then the second electrode tab 233 is the negative electrode tab of the electrode assembly 23. If the first electrode tab 232 is the negative electrode tab of the electrode assembly 23, then the second electrode tab 233 is the positive electrode tab of the electrode assembly 23. For example, the first electrode tab 232 and the second electrode tab 233 are respectively protruding from both ends of the main body portion 231 in the thickness direction X of the wall portion. That is, the second electrode tab 233 is protruding from the end of the main body portion 231 away from the wall portion 211 in the thickness direction X of the wall portion.

[0150] Optionally, the electrode assembly 23 housed within the housing 21 can be one or more. For example, in... Figure 4 In this embodiment, the outer casing 21 of the battery cell 20 has only one electrode assembly 23. Of course, in other embodiments, there may be multiple electrode assemblies 23 housed in the outer casing 21, and the multiple electrode assemblies 23 may be stacked along their thickness direction. For example, the number of electrode assemblies 23 may be two, three, four, five, six, seven or eight, etc.

[0151] In this embodiment, the first electrode terminal 22 serves as the first tab 232 of the electrode assembly 23, acting as the output or input electrode of the battery cell 20, thereby enabling the output or input of electrical energy from the battery cell 20.

[0152] It should be noted that the first electrode terminal 22 is insulated and mounted on the wall portion 211, that is, no electrical connection is formed between the first electrode terminal 22 and the wall portion 211 of the outer casing 21.

[0153] Among them, Figure 4 In the battery cell 20, the second electrode terminal 25 may also include a second electrode terminal 25 for electrical connection to the second tab 233 of the electrode assembly 23, so that the first electrode terminal 22 and the second electrode terminal 25 cooperate to input or output electrical energy of the battery cell 20.

[0154] For example, see Figure 3 and Figure 4 As shown, the second electrode terminal 25 is disposed at one end of the housing 21 away from the wall portion 211 in the thickness direction X of the wall portion, so that the second electrode terminal 25 and the second electrode tab 233 are both located on the same side of the main body portion 231 in the thickness direction X of the wall portion, so that the housing 21 has a structure in which the first electrode terminal 22 and the second electrode terminal 25 are respectively disposed at both ends in the thickness direction X of the wall portion.

[0155] For example, the materials of the first electrode terminal 22 and the second electrode terminal 25 can be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0156] In this embodiment, the first current collector 24 serves to connect the first electrode terminal 22 and the first tab 232 to achieve electrical connection between the first electrode terminal 22 and the electrode assembly 23, thereby reducing the difficulty of connecting the first electrode terminal 22 and the first tab 232.

[0157] In this configuration, at least a portion of the first current-collecting member 24 is disposed between the main body portion 231 and the wall portion 211. That is, the first current-collecting member 24 can be a structure that is only partially located between the main body portion 231 and the wall portion 211, or it can be a structure that is entirely located between the main body portion 231 and the wall portion 211. For example, in... Figure 5 In this structure, the first current collecting member 24 is located entirely between the main body 231 and the wall 211, so that the wall 211, the first current collecting member 24 and the main body 231 are arranged sequentially along the thickness direction X of the wall.

[0158] The first current collector 24 includes an integrally formed first connecting region 241 and a second connecting region 242. The thickness of the first connecting region 241 is greater than the thickness of the second connecting region 242. That is, the first connecting region 241 and the second connecting region 242 of the first current collector 24 are formed by an integral molding process, resulting in two regions of different thicknesses in the first current collector 24. Along the thickness direction X of the wall, the region with a larger thickness in the first current collector 24 is the first connecting region 241, while the region with a smaller thickness is the second connecting region 242. Exemplarily, in this embodiment, the second connecting region 242 with a smaller thickness in the first current collector 24 is a structure formed by stamping. That is, the first current collector 24 is a flat plate structure of uniform thickness, which is stamped to form the first connecting region 241 and the second connecting region 242 with different thicknesses.

[0159] The first connection area 241 is connected to the first tab 232, and the second connection area 242 is welded to the first electrode terminal 22. That is to say, the first connection area 241 with a larger thickness of the first current collector 24 is connected to the first tab 232, while the second connection area 242 with a smaller thickness of the first current collector 24 is welded to the first electrode terminal 22.

[0160] For example, in the embodiments of this application, the first connection area 241 and the first electrode 232 are welded together, for example, by laser welding.

[0161] A through hole 2421 is provided on the second connection area 242. The through hole 2421 penetrates the second connection area 242. That is, the area of ​​the first current collector 24 used for welding and connecting with the first electrode terminal 22 and with a small thickness is provided with a through hole 2421 extending along the thickness direction X of the wall, and the through hole 2421 penetrates the surfaces on both sides of the second connection area 242.

[0162] For example, the material of the first current collector 24 can be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0163] In some embodiments, see Figure 4 As shown, the battery cell 20 may also include a second current collector 26, which serves to connect the second electrode terminal 25 and the second tab 233 to achieve electrical connection between the second electrode terminal 25 and the electrode assembly 23, thereby reducing the difficulty of connecting the second electrode terminal 25 and the second tab 233.

[0164] It should be noted that the structure of the second current collector 26 may be the same as or different from the structure of the first current collector 24. Similarly, the assembly structure of the second current collector 26 with the second electrode terminal 25 and the second tab 233 may be the same as or different from the assembly structure of the first current collector 24 with the first electrode terminal 22 and the first tab 232.

[0165] For example, the material of the second current collector 26 can be various, such as copper, iron, aluminum, steel or aluminum alloy.

[0166] In some embodiments, see Figure 3 and Figure 4 As shown, the battery cell 20 may also include a pressure relief component 27, which is disposed on the housing 21. The pressure relief component 27 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.

[0167] Optionally, the pressure relief component 27 may be disposed on the end cap 213 of the housing 21, or it may be disposed on the housing 212 of the housing 21. For example, in Figure 3 and Figure 4 In the middle, the pressure relief component 27 is disposed on the housing 212 of the outer casing 21.

[0168] Optionally, the pressure relief component 27 and the outer casing 21 can be an integrally formed structure or a separate structure. If the pressure relief component 27 and the outer casing 21 are separate structures, the pressure relief component 27 can be connected to the outer casing 21 by welding or other means. Correspondingly, the pressure relief component 27 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 27 and the outer casing 21 are an integrally formed structure, the pressure relief component 27 is an area on the outer casing 21 with a weak structure, such as an area on the outer casing 21 with a groove.

[0169] In this embodiment, by setting the thickness of the first connection area 241 of the first current collector 24 used for interconnection with the first electrode tab 232 to be greater than the thickness of the second connection area 242 of the first current collector 24 used for welding with the first electrode terminal 22, the first current collector 24 is thinned in the area to be welded with the first electrode terminal 22. This reduces the difficulty of welding the first current collector 24 with the first electrode terminal 22 and also reduces the power required for welding the first current collector 24 with the first electrode terminal 22. This reduces the risk of the welded area of ​​the first electrode terminal 22 being burned by excessive power due to excessive welding power, thereby reducing the risk of insulation or sealing failure of the battery cell 20 during use. To improve the stability of the battery cell 20 in use, by providing through holes 2421 in the thinner second connection area 242, weight reduction and improved mass energy density can be achieved. On the other hand, when the thinner second connection area 242 of the integrally formed first current collector 24 is formed by stamping, the through holes 2421 can provide a certain space for the flow and extrusion of material in the first current collector 24 during the stamping process. This facilitates material flow in the first current collector 24 during the stamping process to form the second connection area 242, which is beneficial to improving the stamping quality of the second connection area 242 of the first current collector 24. In this way, while reducing the risk of insulation failure or sealing failure of the battery cell 20, the processing quality of the first current collector 24 can be improved, thereby improving both the stability of the battery cell 20 in use and the production quality of the battery cell 20.

[0170] According to some embodiments of this application, refer to Figure 7 and Figure 8 , Figure 7A partial cross-sectional view of the battery cell 20 provided in some further embodiments of this application. Figure 8 This is a cross-sectional view of the first current collector 24 of the battery cell 20 provided in some embodiments of this application. In a projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the wall portion 211 is rectangular, and the size of the orthographic projection of the wall portion 211 in the first direction Y is larger than the size of the orthographic projection of the wall portion 211 in the second direction Z. The thickness direction X, the first direction Y, and the second direction Z of the wall portion are mutually perpendicular. The first current collector 24 includes two first connecting regions 241, which are respectively connected to the two ends of a second connecting region 242 along the first direction Y.

[0171] The first connecting region 241 and the second connecting region 242 are arranged along the length direction of the wall portion 211. The first collecting member 24 is formed with two first connecting regions 241 arranged at intervals in the first direction Y, and the second connecting region 242 is connected between the two first connecting regions 241 in the first direction Y.

[0172] Of course, the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 can also have other structures. For example, the first current collector 24 also includes two third connection areas. The two third connection areas are respectively connected to the two ends of the second connection area 242 in the second direction Z, and the two ends of each third connection area in the first direction Y are respectively connected to the two first connection areas 241. The thickness of the third connection area in the thickness direction X of the wall is equal to the thickness of the first connection area 241 in the thickness direction X of the wall. That is to say, one first connection area 241, one third connection area, another first connection area 241 and another third connection area are connected end to end to form a ring structure surrounding the second connection area 242. This allows the first connection area 241 and the third connection area of ​​the first current collector 24 to be used to connect with the first tab 232. This increases the area of ​​the first current collector 24 used to connect with the first tab 232 and reduces the difficulty of assembling the first current collector 24 and the first tab 232.

[0173] In this embodiment, by connecting the first connection area 241 to both ends of the second connection area 242 along the length direction of the wall portion 211, the areas of the first current collector 24 located on both sides of the first electrode terminal 22 in the first direction Y can be connected to the first tab 232. On the one hand, this increases the area and size of the first current collector 24 for connecting to the first tab 232. On the other hand, it allows for adjustment of the connection position between the first tab 232 and the first current collector 24 according to actual conditions, which is beneficial to improving the production flexibility of the battery cell 20.

[0174] According to some embodiments of this application, see Figure 6As shown, the thickness of the first connection area 241 is D1, and the thickness of the second connection area 242 is D2, satisfying 0.1mm≤D1-D2≤1mm.

[0175] For example, the difference between the thickness of the first connection area 241 and the thickness of the second connection area 242 can be 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.8mm, 0.9mm, or 1mm, etc.

[0176] In this embodiment, on the one hand, the thickness difference between the first connection area 241 and the second connection area 242 is set to be greater than or equal to 0.1 mm to improve the thinning effect of the second connection area 242. This further reduces the difficulty of welding the first current collector 24 and the first electrode terminal 22 together, and also further reduces the power required for welding the first current collector 24 and the first electrode terminal 22 together. This further reduces the risk of the welded area of ​​the first electrode terminal 22 being burned by excessive power, which could damage the internal insulation or sealing components of the battery cell 20. On the other hand, setting the thickness difference between the first connection area 241 and the second connection area 242 to be less than or equal to 1 mm can alleviate the phenomenon of excessive thickness difference between the first connection area 241 and the second connection area 242. This can effectively reduce the manufacturing and forming difficulty of the first current collector 24, and when the second connection area 242 is stamped, it can effectively reduce the material flow of the first current collector 24 during the stamping process, which is conducive to further improving the stamping quality of the second connection area 242 of the first current collector 24.

[0177] According to some embodiments of this application, in conjunction with Figure 5 and Figure 6 Please refer to further details. Figure 9 As shown, Figure 9 This is a front view of the first current collector 24 of the battery cell 20 provided in some embodiments of this application, in the thickness direction X of the wall portion. The first electrode terminal 22 has a connection surface 221 facing the second connection region 242 in the thickness direction X of the wall portion, and the connection surface 221 is welded to the second connection region 242. In a projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the hole wall surface of the through hole 2421 lies within the orthographic projection of the connection surface 221.

[0178] The connecting surface 221 is the surface of the first electrode terminal 22 facing the second connecting area 242 in the thickness direction X of the wall and abutting and welding the second connecting area 242.

[0179] In the projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the hole wall of the through hole 2421 lies within the orthographic projection of the connecting surface 221. That is, the connecting surface 221 of the first electrode terminal 22 covers at least a portion of the through hole 2421 in the thickness direction X of the wall portion.

[0180] In this embodiment, by setting at least a portion of the orthographic projection of the hole wall of the through hole 2421 in the projection plane perpendicular to the thickness direction X of the wall portion as located within the orthographic projection of the connection surface 221 of the first electrode terminal 22 in the projection plane perpendicular to the thickness direction X of the wall portion, the connection surface 221 of the first electrode terminal 22 for welding with the second connection area 242 is configured to correspond to at least a portion of the through hole 2421 in the thickness direction X of the wall portion. This facilitates heat dissipation during the welding assembly of the first electrode terminal 22 and the second connection area 242, and the welding positioning between the first electrode terminal 22 and the second connection area 242 can also be achieved through the through hole 2421, which is beneficial to improving the welding quality between the first electrode terminal 22 and the second connection area 242. On the other hand, it enables the first electrode terminal 22 to cover at least a portion of the through hole 2421, thereby reducing the impact of the through hole 2421 on the flow area in the flow path between the first electrode terminal 22 and the first connection area 241.

[0181] In some embodiments, please combine Figure 5 , Figure 6 and Figure 9 As shown, in the projection plane perpendicular to the thickness direction X of the wall portion, the entire orthographic projection of the hole wall surface of the through hole 2421 lies within the orthographic projection of the connecting surface 221. That is, the connecting surface 221 of the first electrode terminal 22 completely covers the through hole 2421 in the thickness direction X of the wall portion.

[0182] In this embodiment, by setting the entire orthographic projection of the hole wall of the through hole 2421 in the projection plane perpendicular to the thickness direction X of the wall to be located within the orthographic projection of the connection surface 221 of the first electrode terminal 22 in the projection plane perpendicular to the thickness direction X of the wall, the connection surface 221 of the first electrode terminal 22 for welding with the second connection area 242 is structured to cover the through hole 2421 in the thickness direction X of the wall. This facilitates the welding assembly of the first electrode terminal 22 and the second connection area 242, and further facilitates heat dissipation during the welding assembly of the first electrode terminal 22 and the second connection area 242, which is beneficial to further improve the welding quality between the first electrode terminal 22 and the second connection area 242. On the other hand, it enables the first electrode terminal 22 to cover the through hole 2421, so that the welding area of ​​the first electrode terminal 22 and the second connection area 242 is located on the outer periphery of the through hole 2421, thereby further reducing the impact of the through hole 2421 on the flow area in the flow path between the first electrode terminal 22 and the first connection area 241.

[0183] According to some embodiments of this application, see Figure 5 , Figure 6 and Figure 9 As shown, the second connection area 242 and the first electrode terminal 22 are welded together and a first solder mark 281 is formed on the second connection area 242. The first solder mark 281 is located on the outer periphery of the through hole 2421 and extends circumferentially along the through hole 2421.

[0184] The second connection area 242 and the first electrode terminal 22 are welded together to form a first solder mark 281 on the second connection area 242. That is, the first solder mark 281 is a solder mark formed on the second connection area 242 after the second connection area 242 and the first electrode terminal 22 are welded together. In other words, the second connection area 242 and the first electrode terminal 22 are welded together to form a solder mark 28. The solder mark 28 includes a first solder mark 281 and a second solder mark 282 that are connected to each other. The first solder mark 281 is embedded in the second connection area 242 and the second solder mark 282 is embedded in the first electrode terminal 22. Correspondingly, the solder mark 28 is a region where the second connection area 242 and the first electrode terminal 22 are welded together to form a fused region or a region where a solder mark is formed. The first solder mark 281 is the portion of the solder mark 28 embedded in the second connection area 242, and the second solder mark 282 is the portion of the solder mark 28 embedded in the first electrode terminal 22, and the second solder mark 282 and the first solder mark 281 are connected to each other.

[0185] In this embodiment, by setting the first solder mark 281 formed on the second connection area 242 as located on the outer periphery of the through hole 2421 and extending circumferentially along the through hole 2421, the regularity of the welding area between the second connection area 242 and the first electrode terminal 22 is improved. On the one hand, the welding difficulty of the first electrode terminal 22 and the second connection area 242 can be reduced, and heat dissipation through the through hole 2421 is facilitated when the first electrode terminal 22 and the second connection area 242 are welded and assembled together. On the other hand, the welding reliability between the first electrode terminal 22 and the second connection area 242 can be improved, and the influence of the through hole 2421 on the flow area on the flow path between the first electrode terminal 22 and the first connection area 241 can be reduced.

[0186] In some embodiments, see Figure 9 As shown, the first solder mark 281 is an annular structure surrounding the through hole 2421. That is, the first solder mark 281 is an annular structure surrounding the outside of the through hole 2421.

[0187] In this embodiment, by setting the first solder mark 281 as an annular structure surrounding the through hole 2421, the first solder mark 281 is a continuous structure with its ends connected. This can improve the welding efficiency of the first electrode terminal 22 and the second connection area 242, thereby increasing the production efficiency of the battery cell 20. On the other hand, it can increase the welding area between the first electrode terminal 22 and the second connection area 242, thereby increasing the current flow area between the first electrode terminal 22 and the second connection area 242, and improving the connection reliability between the first electrode terminal 22 and the second connection area 242.

[0188] In some embodiments, refer to Figure 10 As shown, Figure 10 This is a front view of the first current collector 24 of the battery cell 20 provided in some embodiments of this application in the thickness direction X of the wall portion. The first solder mark 281 is provided at both ends of the through hole 2421 in the circumferential direction, that is, the first solder mark 281 is not connected at the beginning and end of the through hole 2421 in the circumferential direction.

[0189] In this embodiment, by setting the first solder mark 281 to be spaced apart at both ends of the through hole 2421 in the circumferential direction, the first solder mark 281 is not connected at the beginning and end of the circumferential direction of the through hole 2421. This reduces the welding difficulty between the first electrode terminal 22 and the second connection area 242, reduces the influence of the weld pool at the beginning and end of the circumferential direction of the first solder mark 281 in the through hole 2421, and alleviates the phenomenon of excessive temperature caused by the first solder mark 281 being continuously welded at the beginning and end of the circumferential direction of the through hole 2421, thereby improving the welding quality of the first electrode terminal 22 and the second connection area 242.

[0190] In some embodiments, refer to Figure 11 As shown, Figure 11 This is a front view of the first current collector 24 of the battery cell 20 provided in some embodiments of this application in the thickness direction X of the wall portion. The first solder mark portion 281 includes a plurality of sub-solder marks 2811, which are arranged at intervals along the circumference of the through hole 2421. That is, the first solder mark portion 281 is a solder mark structure that is discontinuous in the circumference of the through hole 2421.

[0191] In this embodiment, by configuring the first solder mark 281 as having a structure including a plurality of sub-solder marks 2811 arranged circumferentially along the through hole 2421, the first solder mark is intermittently welded and discontinuous in the circumferential direction of the through hole 2421. This structure can reduce the welding time of the first electrode terminal 22 and the second connection area 242 in a single welding process, thereby alleviating the phenomenon of excessive temperature caused by the continuous welding of the first solder mark 281. This is beneficial to improving the welding quality of the first electrode terminal 22 and the second connection area 242, and also beneficial to reducing the range of the heat-affected zone caused by welding on the first electrode terminal 22 and the second connection area 242.

[0192] According to some embodiments of this application, see Figure 9 , Figure 10 as well as Figure 11 As shown, there are multiple first solder marks 281, which are arranged at intervals in the radial direction of the through hole 2421. That is, the second connection area 242 can form a structure with multiple rings of first solder marks 281 arranged around the through hole 2421 from the inside to the outside. Each ring of first solder marks 281 can be a ring structure, or a structure with intervals at both ends in the circumferential direction of the through hole 2421, or a structure including multiple sub-solder marks 2811, which are arranged at intervals along the circumferential direction of the through hole 2421.

[0193] For example, in Figure 9 , Figure 10 and Figure 11 In the second connection area 242, there are two first solder marks 281 formed on the second connection area 242, and the two second solder marks 282 are arranged at intervals in the radial direction of the through hole 2421. Of course, in other embodiments, the number of first solder marks 281 formed on the second connection area 242 can also be three, four or five, etc.

[0194] In this embodiment, by forming a plurality of first solder marks 281 arranged radially at intervals along the through hole 2421 on the second connection area 242, it is beneficial to further increase the welding area between the first electrode terminal 22 and the second connection area 242, thereby improving the flow area between the first electrode terminal 22 and the second connection area 242, and further improving the connection reliability between the first electrode terminal 22 and the second connection area 242.

[0195] Of course, the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 can also have other structures, for example, see reference. Figure 12 As shown, Figure 12 This is a front view of the first current collector 24 of the battery cell 20 provided in other embodiments of this application in the thickness direction X of the wall portion. A second connection region 242 and a first electrode terminal 22 are welded together, forming a first solder mark 281 on the second connection region 242. The first solder mark 281 includes a plurality of solder marks 2812 and at least one solder mark transition 2813. The solder marks 2812 extend circumferentially along the through hole 2421, and each solder mark 2812 has a first end 2812a and a second end 2812b opposite each other in the circumferential direction of the through hole 2421. The plurality of solder marks 2812 are arranged radially spaced along the through hole 2421. In two adjacent solder marks 2812, the solder mark transition 2813 connects the first end 2812a of one solder mark 2812 and the second end 2812b of the other solder mark 2812.

[0196] The solder body 2812 is a structure in which the first end 2812a and the second end 2812b are not connected to each other and extend circumferentially along the through hole 2421. The multiple solder bodies 2812 of the first solder part 281 are arranged in a structure that surrounds the through hole 2421 from the inside to the outside. The solder transition part 2813 of the first solder part 281 is a structure that connects two adjacent solder bodies 2812. It should be noted that in two adjacent solder bodies 2812, the solder transition part 2813 connects the first end 2812a of one solder body 2812 and the second end 2812b of another solder body 2812, so that the multiple solder bodies 2812 are connected to each other through the solder transition part 2813 to form a continuous solder structure.

[0197] For example, in Figure 12 In the first soldering part 281, there are two soldering bodies 2812 and one soldering transition part 2813. Of course, in other embodiments, the number of soldering bodies 2812 of the first soldering part 281 can also be three, four, five or six, etc.

[0198] In this embodiment, a plurality of solder bodies 2812 of the first solder section 281 are arranged at intervals in the radial direction of the through hole 2421. In two adjacent solder bodies 2812, each solder transition section 2813 connects the first end 2812a of one solder body 2812 and the second end 2812b of the other solder body 2812, so that the first solder section 281 presents a spiral structure surrounding the through hole 2421. This enables the first solder section 281 to have a structure that surrounds the through hole 2421 multiple times and continuously, thereby increasing the welding area between the first electrode terminal 22 and the second connection area 242 while improving the welding efficiency of the first electrode terminal 22 and the second connection area 242.

[0199] According to some embodiments of this application, see Figure 6 As shown, the second connection area 242 and the first electrode terminal 22 are welded together and a first solder mark 281 is formed on the second connection area 242. The minimum distance between the first solder mark 281 and the first connection area 241 is L, which satisfies 2mm≤L≤8mm.

[0200] Wherein, L is the minimum distance between the first solder mark 281 closest to the first connection area 241 among the plurality of first solder marks 281 on the second connection area 242 and the first connection area 241 in a plane perpendicular to the thickness direction X of the wall portion.

[0201] For example, the minimum distance L between the first solder mark 281 and the first connection area 241 can be 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, or 4.7mm. m, 4.8mm, 4.9mm, 5mm, 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, 6mm, 6.1mm, 6.2mm, 6.3mm, 6. 4mm, 6.5mm, 6.6mm, 6.7mm, 6.8mm, 6.9mm, 7mm, 7.1mm, 7.2mm, 7.3mm, 7.4mm, 7.5mm, 7.6mm, 7.7mm, 7.8mm, 7.9mm or 8mm, etc.

[0202] In this embodiment, on the one hand, the minimum distance between the first solder mark 281 formed on the second connection area 242 and the first connection area 241 is set to be greater than or equal to 2mm, so as to reduce the phenomenon that the welding position of the first electrode terminal 22 and the second connection area 242 is too close to the first connection area 241. This helps to reduce the welding difficulty of the first electrode terminal 22 and the second connection area 242 and optimize the welding process of the first electrode terminal 22 and the second connection area 242. On the other hand, the minimum distance between the first solder mark 281 formed on the second connection area 242 and the first connection area 241 is set to be less than or equal to 8mm, so as to shorten the current guiding path between the first solder mark 281 and the first connection area 241. This reduces the impact of the thinned second connection area 242 on the overcurrent area between the first electrode terminal 22 and the first connection area 241, and reduces the current transmission resistance between the first electrode terminal 22 and the first connection area 241, thereby reducing the local temperature rise phenomenon of the first current collector 24 during use.

[0203] According to some embodiments of this application, see Figure 8 As shown, the Vickers hardness of the second connection region 242 is greater than that of the first connection region 241.

[0204] In this embodiment, by setting the Vickers hardness of the thinner second connecting region 242 in the first current collector 24 to be greater than that of the thicker first connecting region 241 in the first current collector 24, the structure of the first current collector 24 with the different thicknesses of the first connecting region 241 and the second connecting region 242 is formed by stamping. The first current collector 24 with this structure can reduce the forming difficulty of the first current collector 24, thereby reducing the manufacturing difficulty of the first current collector 24. On the other hand, it can effectively improve the structural strength of the thinned second connecting region 242 of the first current collector 24, thereby reducing the risk of deformation or cracking of the second connecting region 242 during use.

[0205] According to some embodiments of this application, see Figure 4 , Figure 5 , Figure 6 and Figure 9 As shown, in the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the wall portion 211 is rectangular, and the size of the orthographic projection of the wall portion 211 in the first direction Y is larger than the size of the orthographic projection of the wall portion 211 in the second direction Z. The thickness direction X, the first direction Y, and the second direction Z of the wall portion are mutually perpendicular. The first connecting region 241 and the second connecting region 242 are arranged along the second direction Z, and both the first connecting region 241 and the second connecting region 242 extend along the first direction Y.

[0206] The wall portion 211 is a rectangular plate-like structure, with the first direction Y being the length direction of the wall portion 211 and the second direction Z being the width direction of the wall portion 211. Correspondingly, the first connecting area 241 and the second connecting area 242 are arranged in the width direction of the wall portion 211, and both the first connecting area 241 and the second connecting area 242 extend along the length direction of the wall portion 211.

[0207] In this embodiment, by setting the first connection area 241 and the second connection area 242 to be arranged along the width direction of the wall portion 211 and extending along the length direction of the wall portion 211, it is beneficial to increase the area of ​​the first connection area 241 and the second connection area 242, and can reduce the difficulty of forming the first connection area 241 and the second connection area 242 with different thicknesses in the first current collector 24, thereby reducing the manufacturing difficulty of the first current collector 24.

[0208] According to some embodiments of this application, the battery cell 20 may also have other structures, see reference... Figure 13 , Figure 14 and Figure 15 As shown, Figure 13 This is a partial cross-sectional view of a battery cell 20 provided in some other embodiments of this application. Figure 14 This is an assembly diagram of the two first current collectors 24 of the battery cell 20 provided in some other embodiments of this application. Figure 15 This is a cross-sectional view of two first current collectors 24 of a battery cell 20 provided in some other embodiments of this application. The battery cell 20 may include two first current collectors 24 arranged along the thickness direction X of the wall portion. The two first current collectors 24 are stacked and connected. Along the thickness direction X of the wall portion, a portion of the first tab 232 is located between the two first current collectors 24.

[0209] In this configuration, the two first current collectors 24 of the battery cell 20 are stacked and connected to each other along the thickness direction X of the wall, such that the first electrode terminal 22 is connected to the first tab 232 of the electrode assembly 23 through the two stacked and connected first current collectors 24.

[0210] Along the thickness direction X of the wall, a portion of the first tab 232 is located between the two first current collectors 24. That is, the portion of the first tab 232 used to connect with the first current collectors 24 is a structure that is held between the two first current collectors 24.

[0211] In this embodiment, the battery cell 20 is provided with two first current collectors 24 that are welded to the first electrode terminal 22. The two first current collectors 24 are stacked and connected along the thickness direction X of the wall. By setting part of the first tab 232 between the two first current collectors 24, the two first current collectors 24 can also play a certain clamping role on the first tab 232, which is beneficial to further improve the connection stability between the first tab 232 and the first current collectors 24.

[0212] In some embodiments, see Figure 4 and Figure 15 As shown, along the thickness direction X of the wall, the second connection areas 242 of the two first current collectors 24 are stacked and connected, and the first connection areas 241 of the two first current collectors 24 are arranged at intervals. A portion of the first tab 232 is located between the first connection areas 241 of the two first current collectors 24 and is connected to the first connection areas 241 of the two first current collectors 24.

[0213] The two first current collectors 24 are stacked and connected to each other in the second connection area 242. For example, the second connection areas 242 of the two first current collectors 24 can be connected by mutual contact, bonding or welding.

[0214] Along the thickness direction X of the wall, the first connection areas 241 of the two first current collectors 24 are arranged at intervals to form a receiving space 244 between the first connection areas 241 of the two first current collectors 24. Correspondingly, a portion of the first tab 232 extends into the receiving space 244 and is interconnected with the first connection areas 241 of the two first current collectors 24.

[0215] In this embodiment, by setting the first connection areas 241 of the two first current collectors 24 to be arranged at intervals along the thickness direction X of the wall, and setting a portion of the first tab 232 to be located between and connected to the first connection areas 241 of the two first current collectors 24, the first connection areas 241 of the two first current collectors 24 are configured to cooperate in clamping and connecting the first tab 232. The battery cell 20 with this structure can reduce the risk of cracking of the first tab 232 during use and assembly, which is beneficial to improving the connection quality and reliability between the first tab 232 and the first current collectors 24.

[0216] According to some embodiments of this application, see Figure 15As shown, at least one first current collector 24 is bent to form a bending region 243, and the bending region 243 connects the first connecting region 241 and the second connecting region 242. That is, at least one first current collector 24 is bent to form a bending structure connecting the first connecting region 241 and the second connecting region 242, and this bending structure is the bending region 243, so that the surfaces of the first connecting region 241 and the second connecting region 242 on the same side are arranged at intervals in the thickness direction X of the wall.

[0217] For example, combined Figure 13 and Figure 15 As shown, only one of the two first current collectors 24 near the main body 231 is bent to form a bending region 243. The bending region 243 is bent in the thickness direction X of the wall towards the main body 231 and protrudes from the side of the second connection region 242 facing the main body 231. Of course, in other embodiments, only one of the two first current collectors 24 near the first electrode terminal 22 may be bent to form a bending region 243. The bending region 243 may be bent in the thickness direction X of the wall towards the first electrode terminal 22 and protrudes from the side of the second connection region 242 facing the first electrode terminal 22. Similarly, both first current collectors 24 may have bending regions 243, and the two bending regions 243 may be bent in opposite directions in the thickness direction X of the wall.

[0218] In this embodiment, at least one first current collector 24 is bent to form a bending region 243, and the bending region 243 is a structure that connects the first connection region 241 and the second connection region 242 of the corresponding first current collector 24, so as to realize that the two first current collectors 24 are arranged at intervals along the thickness direction X of the wall and clamp the first electrode tab 232. The structure is simple and easy to implement.

[0219] According to some embodiments of this application, see Figure 14 and Figure 15 As shown, the through holes 2421 on the second connection areas 242 of the two first current collectors 24 are interconnected. That is, in the projection plane perpendicular to the thickness direction X of the wall, at least a portion of the area defined by the orthographic projection of the hole wall of the through hole 2421 on the second connection area 242 of one first current collector 24 overlaps with the area defined by the orthographic projection of the hole wall of the through hole 2421 on the second connection area 242 of the other first current collector 24.

[0220] In this embodiment, by setting the through holes 2421 on the second connection area 242 of the two first current collectors 24 to be interconnected, the through holes 2421 on the second connection area 242 of the two first current collectors 24 are arranged in a structure corresponding to each other in the thickness direction X of the wall. This reduces the difficulty of avoiding the through holes 2421 when the two stacked and connected first current collectors 24 are welded to the first electrode terminal 22, thereby reducing the assembly difficulty of the battery cell 20.

[0221] In some embodiments, please continue to see Figure 14 and Figure 15 As shown, in a projection plane perpendicular to the thickness direction X of the wall, the orthographic projections of the hole walls of the through holes 2421 on the second connection areas 242 of the two first current collectors 24 overlap. That is, in a projection plane perpendicular to the thickness direction X of the wall, the area defined by the orthographic projection of the hole wall of the through hole 2421 on the second connection area 242 of one first current collector 24 completely overlaps with the area defined by the orthographic projection of the hole wall of the through hole 2421 on the second connection area 242 of the other first current collector 24, so that the through holes 2421 on the two first current collectors 24 are of the same size and are correspondingly arranged in the thickness direction X of the wall.

[0222] In this embodiment, by setting the through holes 2421 on the second connection area 242 of the two first current collectors 24 to be completely overlapping, on the one hand, it is possible to first stack and connect the two first current collectors 24 and then process the through holes 2421 in the same way, which is beneficial to optimize the production cycle and improve the production efficiency of the battery cell 20. On the other hand, it can further reduce the difficulty of avoiding the through holes 2421 when the two stacked and connected first current collectors 24 are welded to the first electrode terminal 22, so as to further reduce the assembly difficulty of the battery cell 20.

[0223] According to some embodiments of this application, see Figure 5 and Figure 6As shown, the first electrode terminal 22 has a connecting surface 221 facing the second connecting region 242 in the thickness direction X of the wall portion. The connecting surface 221 is welded to the second connecting region 242. In a projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the connecting surface 221 overlaps with at least a portion of the orthographic projection of the first connecting region 241. Along the thickness direction X of the wall portion, the first connecting region 241 has a first surface 2411 facing the first electrode terminal 22 and a second surface 2412 facing away from the first electrode terminal 22. The first surface 2411 is connected to the connecting surface 221. The second connecting region 242 has a third surface 2422 facing the first electrode terminal 22 and a fourth surface 2423 facing away from the first electrode terminal 22. The first surface 2411 and the third surface 2422 are flush, and the second surface 2412 is closer to the main body 231 than the fourth surface 2423.

[0224] Wherein, in the projection plane perpendicular to the thickness direction X of the wall, at least a portion of the orthographic projection of the connecting surface 221 overlaps with at least a portion of the orthographic projection of the first connecting area 241. That is, the connecting surface 221 of the first electrode terminal 22 has a structure that at least a portion of the first connecting area 241 of the first current collector 24 coincides with the thickness direction X of the wall.

[0225] The first surface 2411 and the third surface 2422 are flush, that is, the surface of the first connection area 241 facing the first electrode terminal 22 and the surface of the second connection area 242 facing the first electrode terminal 22 are coplanar.

[0226] The second surface 2412 is closer to the main body 231 than the fourth surface 2423. In other words, the first connecting region 241 is a structure that protrudes from the surface of the second connecting region 242 facing the main body 231 in the thickness direction X of the wall.

[0227] In this embodiment, in the projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the connecting surface 221 overlaps with at least a portion of the orthographic projection of the first connecting area 241, such that the first electrode terminal 22 and the first connecting area 241 have an overlapping area in the thickness direction X of the wall portion, so that the first electrode terminal 22 and the first connecting area 241 can share a portion of space in the direction perpendicular to the thickness direction X of the wall portion. This is achieved by setting the first surface 2411 of the first connecting area 241 facing the first electrode terminal 22 and the third surface 2422 of the second connecting area 242 facing the first electrode terminal 22 to be flush and coplanar, and setting the second surface 2412 of the first connecting area 241 away from the first electrode terminal 22 to be relatively... The second connection area 242 is positioned closer to the main body 231 than the fourth surface 2423 of the first electrode terminal 22. This structure makes the first connection area 241 protrude from the side of the second connection area 242 away from the first electrode terminal 22 and is flush with the side of the second connection area 242 facing the first electrode terminal 22. This reduces the interference caused by the welding of the first connection area 241 to the connection surface 221 of the first electrode terminal 22 and the second connection area 242 when the thicknesses of the first connection area 241 and the second connection area 242 are different. This helps to reduce the welding gap between the connection surface 221 of the first electrode terminal 22 and the second connection area 242, thereby improving the welding quality of the first electrode terminal 22 and the second connection area 242.

[0228] According to some embodiments of this application, see Figure 7 and Figure 8 As shown, the first electrode terminal 22 has a connecting surface 221 facing the second connecting area 242 in the thickness direction X of the wall portion. The connecting surface 221 is welded to the second connecting area 242. In the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the connecting surface 221 and the orthographic projection of the first connecting area 241 do not overlap. Along the thickness direction X of the wall portion, the first connecting area 241 has a first surface 2411 facing the first electrode terminal 22 and a second surface 2412 facing away from the first electrode terminal 22. The first surface 2411 is connected to the connecting surface 221. The second connecting area 242 has a third surface 2422 facing the first electrode terminal 22 and a fourth surface 2423 facing away from the first electrode terminal 22. The second surface 2412 and the fourth surface 2423 are flush. The first surface 2411 is further away from the main body 231 than the third surface 2422.

[0229] In the projection plane perpendicular to the thickness direction X of the wall, the orthographic projection of the connecting surface 221 and the orthographic projection of the first connecting area 241 do not overlap. That is to say, the connecting surface 221 of the first electrode terminal 22 is a structure that does not coincide with the first connecting area 241 of the first current collector 24 in the thickness direction X of the wall, and the two do not obstruct each other.

[0230] The second surface 2412 and the fourth surface 2423 are flush, that is, the surface of the first connection area 241 that is away from the first electrode terminal 22 and the surface of the second connection area 242 that is away from the first electrode terminal 22 are coplanar.

[0231] The first surface 2411 is farther away from the main body 231 than the third surface 2422. That is, the first connecting area 241 is a structure that protrudes from the surface of the second connecting area 242 away from the main body 231 in the thickness direction X of the wall. After the connecting surface 221 of the first electrode terminal 22 and the second connecting area 242 are welded together, the first surface 2411 is farther away from the main body 231 than the connecting surface 221.

[0232] In this embodiment, in the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the connecting surface 221 and the orthographic projection of the first connecting area 241 do not overlap, so that the first electrode terminal 22 and the first connecting area 241 do not have an overlapping area in the thickness direction X of the wall portion. Specifically, by setting the second surface 2412 of the first connecting area 241 facing away from the first electrode terminal 22 and the fourth surface 2423 of the second connecting area 242 facing away from the first electrode terminal 22 to be flush and coplanar, and by setting the first surface 2411 of the first connecting area 241 facing the first electrode terminal 22 to be further away from the main body 231 than the third surface 2422 of the second connecting area 242 facing the first electrode terminal 22, the first connecting area 241... The structure is such that the second connection area 242 protrudes from the side facing the first electrode terminal 22 and is flush with the side of the second connection area 242 away from the first electrode terminal 22. After the connection surface 221 of the first electrode terminal 22 and the second connection area 242 are welded together, the first surface 2411 of the first connection area 241 facing the first electrode terminal 22 is further away from the main body 231 than the connection surface 221. Thus, even when the thicknesses of the first connection area 241 and the second connection area 242 are different, the first connection area 241 and the first electrode terminal 22 of the first current collector 24 can share a portion of the space in the thickness direction X of the wall. This is beneficial for optimizing the internal space utilization of the battery cell 20 and improving the energy density of the battery cell 20.

[0233] According to some embodiments of this application, the first connection area 241 and the first tab 232 are welded together.

[0234] For example, the first connection area 241 and the first electrode 232 are laser welded. Of course, in other embodiments, the first connection area 241 and the first electrode 232 can also be ultrasonically welded.

[0235] In this embodiment, by setting the first connection area 241 and the first tab 232 of the first current collector 24 as a welded connection, the connection stability and reliability between the first connection area 241 and the first tab 232 can be improved, and the current flow performance between the first connection area 241 and the first tab 232 can be improved.

[0236] According to some embodiments of this application, see Figure 5 As shown, the first electrode terminal 22 has a connecting portion 222, which is located on the side of the wall portion 211 facing the electrode assembly 23 in the thickness direction X of the wall portion. The connecting portion 222 is welded to the second connecting area 242, and a second solder mark 282 is formed on the connecting portion 222. The battery cell 20 also includes an insulating component 29, at least a portion of which is located between the connecting portion 222 and the wall portion 211 in the thickness direction X of the wall portion to insulate the connecting portion 222 and the wall portion 211. In a projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the insulating component 29 overlaps with the orthographic projection of the second solder mark.

[0237] The connecting portion 222 is the portion where the first electrode terminal 22 is located inside the housing 21 and at least partially overlaps with the wall portion 211 in the thickness direction X of the wall portion.

[0238] The connecting portion 222 is welded to the second connecting area 242 and a second solder mark 282 is formed on the connecting portion 222. That is, the second solder mark 282 in the solder mark 28 formed by welding the first electrode terminal 22 and the second connecting area 242 together is a structure embedded in the connecting portion 222 of the first electrode terminal 22.

[0239] It should be noted that in the embodiment where the connecting portion 222 of the first electrode terminal 22 is welded to the second connecting area 242, the surface of the connecting portion 222 facing the second connecting area 242 in the thickness direction X of the wall portion is part of the connecting surface 221.

[0240] It should be noted that, in the embodiments of this application, the insulating component 29 includes an insulating member 291 and a sealing member 292. At least a portion of the insulating member 291 is located between the connecting portion 222 and the wall portion 211 to insulate and isolate the connecting portion 222 and the wall portion 211. The sealing member 292 is disposed between the first electrode terminal 22 and the wall portion 211 to seal the gap between the first electrode terminal 22 and the wall portion 211.

[0241] For example, the insulating element 291 and the sealing element 292 can be made of various materials, such as rubber, plastic or silicone.

[0242] In the projection plane perpendicular to the thickness direction X of the wall portion, the orthographic projection of the insulating component 29 at least partially overlaps with the orthographic projection of the second solder mark. That is, the second solder mark 282 and the insulating component 29 have a structure that at least partially coincides in the thickness direction X of the wall portion. Optionally, see [link to relevant documentation]. Figure 5 As shown, in a projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the seal 292 of the insulating assembly 29 overlaps with the orthographic projection of the second solder mark. See [reference needed]. Figure 7 As shown, in the projection plane perpendicular to the thickness direction X of the wall portion, at least a portion of the orthographic projection of the insulating member 291 of the insulating assembly 29 overlaps with the orthographic projection of the second solder mark.

[0243] In this embodiment, by providing an insulating component 29 between the connection portion 222 and the wall portion 211 of the first electrode terminal 22, the insulating component 29 can insulate and isolate the connection portion 222 and the wall portion 211, thereby reducing the risk of short circuit between the first electrode terminal 22 and the wall portion 211. Specifically, by setting the orthographic projection of the insulating component 29 in the projection plane perpendicular to the thickness direction X of the wall portion to at least partially overlap with the orthographic projection of the second solder in the projection plane perpendicular to the thickness direction X of the wall portion, and since the first current collector 24 is a structure in which the area to be welded to the first electrode terminal 22 is thinned, the phenomenon of burning or damaging the insulating component 29 in the area to be welded to the first electrode terminal 22 can be alleviated by reducing the power required for the first current collector 24 to be welded to the first electrode terminal 22. This reduces the risk of insulation failure in the battery cell 20 during use and is beneficial to improving the stability and reliability of the battery cell 20.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] 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.

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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.

[0252] 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.

[0253] The electrical device can be any of the aforementioned devices or systems that utilize battery cells 20.

[0254] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0255] 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: The outer shell has walls; A first electrode terminal is disposed on the wall portion; An electrode assembly is disposed within the housing. The electrode assembly includes a main body and a first electrode tab, the first electrode tab protruding from the main body. as well as A first current collector is at least partially disposed between the main body and the wall. The first current collector includes an integrally formed first connection area and a second connection area. The thickness of the first connection area is greater than the thickness of the second connection area. The first connection area is connected to the first electrode tab, and the second connection area is welded to the first electrode terminal. A through hole is provided on the second connection area, and the through hole penetrates the second connection area.

2. The battery cell according to claim 1, characterized in that, In a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the wall portion is rectangular, and the size of the orthographic projection of the wall portion in the first direction is larger than the size of the orthographic projection of the wall portion in the second direction. The thickness direction, the first direction, and the second direction of the wall portion are all perpendicular to each other. The first current collection component includes two first connection areas, and along the first direction, the two first connection areas are respectively connected to the two ends of the second connection area.

3. The battery cell according to claim 1, characterized in that, The thickness of the first connection area is D1, and the thickness of the second connection area is D2, satisfying that 0.1mm≤D1-D2≤1mm.

4. The battery cell according to any one of claims 1-3, characterized in that, The first electrode terminal has a connection surface facing the second connection area in the thickness direction of the wall portion, and the connection surface is welded to the second connection area. In a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the hole wall of the through hole lies within the orthographic projection of the connecting surface.

5. The battery cell according to claim 4, characterized in that, In a projection plane perpendicular to the thickness direction of the wall, the entire orthographic projection of the hole wall of the through hole lies within the orthographic projection of the connecting surface.

6. The battery cell according to claim 4, characterized in that, The second connection area and the first electrode terminal are welded together, and a first solder mark is formed on the second connection area. The first solder mark is located on the outer periphery of the through hole and extends circumferentially along the through hole.

7. The battery cell according to claim 6, characterized in that, The first solder mark is an annular structure surrounding the through hole.

8. The battery cell according to claim 6, characterized in that, The first solder mark is spaced apart at both ends of the through hole in the circumferential direction.

9. The battery cell according to claim 6, characterized in that, The first solder mark includes a plurality of sub-solder marks, which are arranged at intervals along the circumference of the through hole.

10. The battery cell according to claim 6, characterized in that, There are multiple first solder marks, and the multiple first solder marks are arranged at intervals in the radial direction of the through hole.

11. The battery cell according to claim 4, characterized in that, The second connection area and the first electrode terminal are welded together, and a first solder mark is formed on the second connection area; The first solder mark includes a plurality of solder mark bodies and at least one solder mark transition portion. The solder mark bodies extend circumferentially along the through hole and have opposing first and second ends in the circumferential direction of the through hole. The plurality of solder mark bodies are arranged radially spaced along the through hole. In two adjacent solder mark bodies, the solder mark transition portion connects the first end of one solder mark body and the second end of the other solder mark body.

12. The battery cell according to any one of claims 1-3, characterized in that, The second connection area and the first electrode terminal are welded together to form a first solder mark on the second connection area. The minimum distance between the first solder mark and the first connection area is L, which satisfies 2mm≤L≤8mm.

13. The battery cell according to any one of claims 1-3, characterized in that, The Vickers hardness of the second connection region is greater than that of the first connection region.

14. The battery cell according to claim 1, characterized in that, In a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the wall portion is rectangular, and the size of the orthographic projection of the wall portion in the first direction is larger than the size of the orthographic projection of the wall portion in the second direction. The thickness direction, the first direction, and the second direction of the wall portion are all perpendicular to each other. The first connection area and the second connection area are arranged along the second direction, and both the first connection area and the second connection area extend along the first direction.

15. The battery cell according to any one of claims 1-3, characterized in that, The battery cell includes two first current collectors arranged along the thickness direction of the wall, and the two first current collectors are stacked and connected. Along the thickness direction of the wall portion, a portion of the first electrode ear is located between the two first current collectors.

16. The battery cell according to claim 15, characterized in that, Along the thickness direction of the wall, the second connection areas of the two first current collecting components are stacked and connected, and the first connection areas of the two first current collecting components are arranged at intervals. The first electrode portion is located between the first connection areas of the two first current collectors and is connected to the first connection areas of the two first current collectors.

17. The battery cell according to claim 16, characterized in that, At least one of the first current collector components is bent to form a bending area, and the bending area connects the first connection area and the second connection area.

18. The battery cell according to claim 16, characterized in that, The through holes on the second connection area of ​​the two first current collectors are interconnected.

19. The battery cell according to claim 18, characterized in that, In a projection plane perpendicular to the thickness direction of the wall, the orthographic projections of the hole walls of the through holes on the second connection areas of the two first current collectors overlap.

20. The battery cell according to any one of claims 1-3, characterized in that, The first electrode terminal has a connecting surface facing the second connecting area in the thickness direction of the wall portion. The connecting surface is welded to the second connecting area. In a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the connecting surface overlaps with at least a portion of the orthographic projection of the first connecting area. Along the thickness direction of the wall portion, the first connection area has a first surface facing the first electrode terminal and a second surface away from the first electrode terminal, the first surface being connected to the connection surface. The second connection area has a third surface facing the first electrode terminal and a fourth surface away from the first electrode terminal, the first surface and the third surface being flush, and the second surface being closer to the main body portion than the fourth surface.

21. The battery cell according to any one of claims 1-3, characterized in that, The first electrode terminal has a connection surface facing the second connection area in the thickness direction of the wall portion. The connection surface is welded to the second connection area. In a projection plane perpendicular to the thickness direction of the wall portion, the orthographic projection of the connection surface and the orthographic projection of the first connection area do not overlap. Along the thickness direction of the wall portion, the first connection area has a first surface facing the first electrode terminal and a second surface away from the first electrode terminal, the first surface being connected to the connection surface; the second connection area has a third surface facing the first electrode terminal and a fourth surface away from the first electrode terminal, the second surface and the fourth surface being flush; and the first surface being further away from the main body portion than the third surface.

22. The battery cell according to any one of claims 1-3, characterized in that, The first connection area and the first electrode tab are welded together.

23. The battery cell according to any one of claims 1-3, characterized in that, The first electrode terminal has a connecting portion located on the side of the wall facing the electrode assembly in the thickness direction of the wall portion, and the connecting portion is welded to the second connecting area and a second solder mark is formed on the connecting portion; The battery cell further includes an insulating component, at least a portion of which is located between the connecting portion and the wall portion in the thickness direction of the wall portion to insulate the connecting portion and the wall portion. In a projection plane perpendicular to the thickness direction of the wall portion, at least a portion of the orthographic projection of the insulating component overlaps with the orthographic projection of the second solder mark.

24. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-23.

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

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