Battery cell, battery, and electric device

Abstract

A battery cell (20), a battery (100), and an electric device, relating to the technical field of batteries. The battery cell (20) comprises a casing (21), a first electrode terminal (22), and electrode assemblies (23). The casing (21) has a wall portion (211). The first electrode terminal (22) is insulated from and mounted on the casing (21). The electrode assemblies (23) are accommodated in the casing (21), each electrode assembly (23) comprises a main body (231) and a first tab (232), the first tab (232) is arranged on the main body (231), and the first tab (232) is electrically connected to the first electrode terminal (22). An electrode assembly (23) further comprises a collection tab (233), the collection tab (233) is arranged on the main body (231), the collection tab (233) has the same polarity as the first tab (232), the collection tab (233) is electrically connected to the wall portion (211), and the minimum current passing area of the collection tab (233) is less than the minimum current passing area of the first tab (232). More heat is generated by the collection tab (233) when a short circuit occurs to the battery cell (20) and the heat accumulates more quickly, so that the collection tab (233) can blow before the first tab (232), thereby cutting off the short-circuit path to alleviate damage to an information collection device, and improving the reliability of the battery cell (20) in use.

Description

Battery cells, batteries and electrical devices Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] In recent years, new energy vehicles have experienced rapid development. In the electric vehicle sector, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also growing. As a core component of new energy vehicles, batteries have high requirements in terms of reliability and service life.

[0003] In battery technology, to ensure the safety of battery cells, information collection equipment is generally used to monitor the usage information of battery cells to obtain the usage status of the battery cells. However, the existing battery cells are very prone to damage to the information collection equipment during the performance monitoring process, and the battery cells are very prone to short circuit risks, resulting in low reliability of the battery cells.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the reliability of the battery cell.

[0006] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell, a first electrode terminal and an electrode assembly; the shell has a wall portion; the first electrode terminal is insulated and mounted on the shell; the electrode assembly is accommodated in the shell, the electrode assembly comprises a main body portion and a first pole tab, the first pole tab is arranged on the main body portion, and the first pole tab is electrically connected to the first electrode terminal; wherein, the electrode assembly further comprises a collecting pole tab, the collecting pole tab is arranged on the main body portion, the collecting pole tab has the same polarity as the first pole tab, the collecting pole tab is electrically connected to the wall portion, and the minimum flow area of ​​the collecting pole tab is smaller than the minimum flow area of ​​the first pole tab.

[0007] In the above technical solution, a collecting tab with the same polarity as the first tab is provided on the electrode assembly, and the collecting tab is electrically connected to the wall of the shell so that the positive or negative pole of the electrode assembly can be electrically connected to the shell, so that the information collection device can collect the usage information of the battery cell after being electrically connected to the shell, thereby facilitating the information collection device to connect the battery cell and collect data, which is conducive to reducing the difficulty of data collection for the battery cell, wherein the minimum flow area of ​​the collecting tab is set to be smaller than the minimum flow area of ​​the first tab, so that the minimum cross-sectional area of ​​the collecting tab on the path through which current passes is smaller than the minimum cross-sectional area of ​​the first tab on the path through which current passes. The collection ear has a larger area than the first ear, so that the resistance of the collection ear at the minimum flow area is greater than the resistance of the first ear. Therefore, within the same time, the heat generated by the collection ear when the electrode assembly inside the battery cell and the shell overlap and short-circuit occurs is higher and the heat accumulates faster, so that the collection ear can be melted first compared to the first ear when the electrode assembly inside the battery cell and the shell overlap and short-circuit occurs, so that the battery cell can disconnect the electrical connection between the collection ear and the shell after a short circuit occurs, and then cut off the short-circuit path, so as to alleviate the damage of the information collection equipment, and can effectively reduce the risk of further use of the battery cell, which is conducive to improving the reliability of the battery cell.

[0008] In some embodiments, the minimum flow area of ​​the collecting tab is S1, which satisfies 2mm 2 ≤S1≤20mm 2 .

[0009] In the above technical solution, by setting the minimum flow area of ​​the collecting tab to 2mm 2 Up to 20mm 2 On the one hand, the minimum flow area of ​​the collector tab is set to be greater than or equal to 2mm 2 , in order to improve the structural strength of the collection tab, thereby reducing the risk of accidental breakage of the collection tab during use, which is beneficial to improving the service life and stability of the battery cell. On the other hand, the minimum flow area of ​​the collection tab is set to be less than or equal to 20mm 2 , in order to alleviate the phenomenon that the collection tab takes too long to melt when a short circuit occurs in the battery cell, and make the collection tab easier to melt, so that the collection tab can be quickly melted when a short circuit occurs in the battery cell to cut off the short circuit path, thereby further alleviating the phenomenon of damage to the information collection equipment and further improving the reliability of the battery cell. Therefore, the minimum flow area of ​​the collection tab is set to 2mm 2 Up to 20mm 2 While ensuring that the collecting tabs have sufficient strength during use, they can also ensure that the collecting tabs quickly fuse when a short circuit occurs in the battery cell.

[0010] In some embodiments, a portion of the collecting tab forms a weak section, and the minimum flow area of ​​the weak section is the minimum flow area S1 of the collecting tab.

[0011] In the above technical solution, a weak section is formed on the collecting tab so that the minimum flow area of ​​the weak section of the collecting tab is the minimum flow area of ​​the collecting tab, so that when a short circuit occurs in the battery cell, the weak section of the collecting tab can be melted. On the one hand, by setting a weak section on the collecting tab, the minimum flow area of ​​the collecting tab can be made smaller than the minimum flow area of ​​the first tab, the structure is simple, and easy to manufacture. On the other hand, the melting position of the collecting tab can be controlled, and the melting position can be controlled in the area where the weak section is located, so as to facilitate the assembly of the collecting tab and avoid the weak section during the assembly process, which is conducive to reducing the difficulty of assembling the collecting tab.

[0012] In some embodiments, along the extension direction of the collecting tab, the length of the weak section is L, which satisfies 0.3 mm ≤ L ≤ 5 mm.

[0013] In the above technical solution, by setting the length of the weak section in the extension direction of the collecting tab to 0.3mm to 5mm, on the one hand, the length of the weak section is set to be greater than or equal to 0.3mm, so that the collecting tab has sufficient space to fuse when a short circuit occurs in the battery cell, thereby effectively reducing the phenomenon of incorrect overlap of the weak section of the collecting tab after melting, so as to reduce the overlap risk of the collecting tab after melting. On the other hand, the length of the weak section is set to be less than or equal to 5mm to alleviate the phenomenon of excessive space occupied by the weak section, and can alleviate the phenomenon of redundancy in the collecting tab, thereby improving the internal space utilization of the battery cell. Therefore, setting the length of the weak section in the extension direction of the collecting tab to 0.3mm to 5mm can reduce the risk of incorrect overlap after the weak section of the collecting tab is melted, while also effectively saving the space occupied by the weak section of the collecting tab.

[0014] In some embodiments, the collecting tab further includes a first connecting segment, the minimum flow area of ​​the first connecting segment is larger than the minimum flow area of ​​the weak segment, and the first connecting segment connects the wall portion and the weak segment.

[0015] In the above technical solution, the collecting electrode ear is further provided with a first connecting section, so that the weak section of the collecting electrode ear is a structure connected to the wall portion through the first connecting section, and the minimum flow area of ​​the first connecting section is greater than the minimum flow area of ​​the weak section, thereby achieving that the collecting electrode ear can be melted at the weak section while also being able to improve the connection area and connection reliability between the collecting electrode ear and the wall portion through the structure connected to the wall portion through the first connecting section, which is beneficial to improving the flow area between the collecting electrode ear and the wall portion.

[0016] In some embodiments, the first connecting section includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the wall portion, the second connecting portion connects the first connecting portion and the weak section, and the second connecting portion does not contact the wall portion.

[0017] In the above technical solution, the first connecting section of the collecting tab includes a first connecting portion and a second connecting portion that are connected to each other, and the first connecting portion and the second connecting portion are respectively connected to the wall portion and the weak section, so that the weak section is a structure connected to the wall portion after passing through the second connecting portion and the first connecting portion in sequence, and the second connecting portion does not contact the wall portion, so that the area where the first connecting section and the weak section are connected to each other is a part that does not contact the wall portion, thereby enabling the weak section of the collecting tab to be a suspended structure, and thus effectively reducing the phenomenon of the weak section of the collecting tab being mistakenly overlapped with the wall portion after melting, which is beneficial to reducing the risk of overlap between the weak section of the collecting tab and the wall portion after melting.

[0018] In some embodiments, the first connecting portion is welded to the wall portion, and along the thickness direction of the wall portion, the first connecting portion has a first surface facing the wall portion and a second surface away from the wall portion, and the first surface is connected to the wall portion; wherein the first surface is a rough surface; and / or the second surface is a rough surface.

[0019] In the above technical solution, the first connection part of the first connection section is connected to the wall portion through a welding connection structure, which is beneficial to improving the connection reliability and connection stability between the first connection section and the wall portion. Among them, by setting the first surface of the first connection part facing the wall portion as a rough surface to improve the roughness of the first connection part, the welding reliability between the first connection part and the wall portion can be improved, which is beneficial to improving the welding quality between the first connection part and the wall portion. Similarly, by setting the second surface of the first connection part facing away from the wall portion as a rough surface to improve the roughness of the first connection part, the welding reliability between the first connection part and the wall portion can be improved, which is beneficial to improving the welding quality between the first connection part and the wall portion.

[0020] In some embodiments, the collecting tab further includes a second connecting segment, the minimum flow area of ​​the second connecting segment is larger than the minimum flow area of ​​the weak segment, and the second connecting segment connects the weak segment and the main body.

[0021] In the above technical solution, the collecting electrode ear is also provided with a second connecting section, so that the weak section of the collecting electrode ear is a structure connected to the main body of the electrode assembly through the second connecting section, and the minimum flow area of ​​the second connecting section is greater than the minimum flow area of ​​the weak section, so that the collecting electrode ear can be melted at the weak section while the structure connected to the main body through the second connecting section can improve the connection area and connection reliability between the collecting electrode ear and the main body, which is beneficial to improve the flow area between the collecting electrode ear and the main body.

[0022] In some embodiments, the collecting tab further includes a first connecting segment, the first connecting segment includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the wall portion, the second connecting portion connects the first connecting portion and the weak segment, and the second connecting portion does not contact the wall portion; wherein, along the extension direction of the collecting tab, the length of the second connecting portion is greater than the length of the second connecting segment.

[0023] In the above technical solution, the collecting tab is further provided with a first connecting section, which includes a first connecting portion and a second connecting portion that are interconnected, the first connecting portion and the second connecting portion respectively connecting the wall portion and the weak section, and the second connecting portion does not contact the wall portion, so that the area where the first connecting section and the weak section are interconnected is a portion that does not contact the wall portion, and by setting the length of the second connecting portion in the extension direction of the collecting tab to be greater than the length of the second connecting portion in the extension direction of the collecting tab, the weak section of the collecting tab is suspended and away from the wall portion, thereby further reducing the phenomenon of the weak section of the collecting tab being mistakenly overlapped with the wall portion after melting, so as to further reduce the risk of overlapping between the weak section of the collecting tab and the wall portion after melting.

[0024] In some embodiments, along the thickness direction of the wall portion, the collecting tab is provided at one end of the main body portion facing the wall portion.

[0025] In the above technical solution, by arranging the collecting tab at one end of the main body facing the wall in the thickness direction of the wall, so that the collecting tab is a structure arranged relative to the wall in the thickness direction of the wall, on the one hand, the difficulty of assembling the collecting tab and the wall can be reduced, which is beneficial to improving the production efficiency of the battery cell; on the other hand, there is no need to excessively extend the collecting tab, which is beneficial to reducing the redundancy of the collecting tab, thereby reducing the risk of overlap between the collecting tab and other components, and reducing the risk of the collecting tab being inserted upside down into the main body of the electrode assembly.

[0026] In some embodiments, the first electrode terminal is insulated and mounted on the wall portion, and along a thickness direction of the wall portion, the first electrode tab is disposed at one end of the main body portion facing the wall portion.

[0027] In the above technical solution, the first electrode terminal is insulated and installed on the wall portion, and the first pole ear is arranged at one end of the main body portion facing the wall portion in the thickness direction of the wall portion, so that the first electrode terminal and the first pole ear are located on the same side of the main body portion in the thickness direction of the wall portion. On the one hand, the difficulty of assembling the first pole ear and the first electrode terminal can be reduced, which is beneficial to improving the production efficiency of the battery cell. On the other hand, there is no need to excessively extend the first pole ear, which is beneficial to reducing the redundancy of the first pole ear, thereby reducing the risk of overlap between the first pole ear and other components, and reducing the risk of the first pole ear being inserted upside down into the main body of the electrode assembly.

[0028] In some embodiments, the first electrode tab and the collecting electrode tab are spaced apart and disposed at the same end of the main body.

[0029] In the above technical solution, by arranging the first pole tab and the collecting pole tab to be located at the same end of the main body, and the first pole tab and the collecting pole tab are arranged at intervals, it is convenient to lead out the first pole tab and the collecting pole tab with the same polarity at the same end of the main body, which is beneficial to reduce the manufacturing difficulty of the electrode assembly, thereby improving the production efficiency of the battery cell, and can reduce the risk of overlap between the first pole tab and the collecting pole tab.

[0030] In some embodiments, the minimum distance between the first electrode tab and the collection electrode tab is D1, satisfying D1 ≥ 5 mm.

[0031] In the above technical solution, by setting the distance between the first pole tab and the collecting pole tab to be greater than or equal to 5 mm, the spacing between the first pole tab and the collecting pole tab is further expanded, thereby further reducing the overlap risk between the first pole tab and the collecting pole tab, and further reducing the overlap phenomenon between the collecting pole tab and the first pole tab after melting, thereby reducing the overlap risk between the wall portion and the first pole tab.

[0032] In some embodiments, the battery cell further includes a second electrode terminal, which is insulated and mounted on the housing; the electrode assembly further includes a second pole tab, which is electrically connected to the second electrode terminal, the polarity of the second pole tab is opposite to that of the first pole tab, the second pole tab and the first pole tab are arranged at the same end of the main body, and the second pole tab and the first pole tab are spaced apart along the first direction; wherein, along the first direction, the collection pole tab is located between the first pole tab and the second pole tab.

[0033] In the above technical solution, the second pole tab and the first pole tab of the electrode assembly are both arranged at the same end of the main body, so that the first pole tab and the second pole tab are easily led out at the same end of the main body, which is beneficial to reducing the manufacturing difficulty of the electrode assembly and improving the production efficiency of the battery cell. Specifically, by arranging the first pole tab and the second pole tab at intervals along the first direction and arranging the collecting pole tab between the first pole tab and the second pole tab in the first direction, the risk of short circuit between the first pole tab and the second pole tab can be reduced, and the risk of short circuit between the collecting pole tab and the second pole tab can be reduced.

[0034] In some embodiments, along the first direction, the distance between the collecting tab and the first tab is smaller than the distance between the collecting tab and the second tab.

[0035] In the above technical solution, by setting the distance between the collecting pole ear and the second pole ear in the first direction to be greater than the distance between the collecting pole ear and the first pole ear in the first direction, the collecting pole ear is closer to the first pole ear in the first direction, so as to further reduce the overlap between the collecting pole ear and the second pole ear with different polarities, thereby effectively reducing the risk of short circuit between the collecting pole ear and the second pole ear during use of the battery cell.

[0036] In some embodiments, along the first direction, the minimum distance between the second electrode tab and the collection electrode tab is D2, satisfying D2 ≥ 5 mm.

[0037] In the above technical solution, by setting the distance between the second pole tab and the collecting pole tab to be greater than or equal to 5 mm, the spacing between the second pole tab and the collecting pole tab is further expanded, thereby further reducing the short circuit phenomenon between the second pole tab and the collecting pole tab, thereby reducing the risk of short circuit between the second pole tab and the collecting pole tab with different polarities.

[0038] In some embodiments, the second electrode terminal is insulated and mounted on the wall portion, and the second electrode tab is provided at one end of the main body portion facing the wall portion along the thickness direction of the wall portion, and the thickness direction of the wall portion is perpendicular to the first direction.

[0039] In the above technical solution, the second electrode terminal is insulated and installed on the wall portion, and the second pole ear is arranged at one end of the main body facing the wall portion in the thickness direction of the wall portion, so that the second electrode terminal and the second pole ear are both located on the side of the main body facing the wall portion in the thickness direction of the wall portion. On the one hand, the difficulty of assembling the second pole ear and the second electrode terminal can be reduced, which is beneficial to improving the production efficiency of the battery cell. On the other hand, there is no need to excessively extend the second pole ear, which is beneficial to reducing the redundancy of the second pole ear, thereby reducing the risk of overlap between the second pole ear and other components, and reducing the risk of the second pole ear being upside down inserted into the main body of the electrode assembly.

[0040] In some embodiments, the collecting tab is connected to the wall portion by welding.

[0041] In the above technical solution, the welding connection structure is used to connect the collecting tab and the wall portion, which is conducive to improving the connection reliability and stability between the collecting tab and the wall portion, thereby reducing the phenomenon of failure of the connection between the collecting tab and the wall portion due to accidental separation of the collecting tab and the wall portion during the use of the battery cell.

[0042] In some embodiments, the welding area between the collecting tab and the wall is S2, which satisfies 30mm 2 ≤S2≤100mm 2 .

[0043] In the above technical solution, the welding area between the collecting tab and the wall is set to 30mm 2 Up to 100mm 2 On the one hand, the welding area between the collecting tab and the wall is set to be greater than or equal to 30mm 2 , in order to improve the welding effect between the collecting tab and the wall, thereby improving the connection reliability and stability between the collecting tab and the wall. On the other hand, the welding area between the collecting tab and the wall is set to be less than or equal to 100mm 2 , in order to reduce the welding difficulty between the collecting tab and the wall, and reduce the welding power required for welding the collecting tab and the wall, thereby effectively reducing the assembly difficulty between the collecting tab and the wall, which is beneficial to improving the production efficiency of the battery cell and reducing the production cost of the battery cell. Therefore, the welding area between the collecting tab and the wall is set to 30mm 2 Up to 100mm 2 While taking into account the welding quality between the collecting pole ear and the wall portion, it can also effectively reduce the welding and assembly difficulty between the collecting pole ear and the wall portion.

[0044] In some embodiments, the first tab includes M tab sheets stacked together, and the collection tab includes N tab sheets stacked together, satisfying M>N.

[0045] In the above technical solution, by making the number of stacked tabs of the collecting tab smaller than the number of stacked tabs of the first tab, since the overcurrent requirement of the collecting tab is smaller than that of the first tab, the collecting tab can be electrically connected to the wall of the shell and can be used for data collection by the information collection equipment while reducing the manufacturing difficulty of the collecting tab, thereby improving the production efficiency of the battery cell.

[0046] In some embodiments, the first tab is a positive tab of the electrode assembly.

[0047] In the above technical solution, by setting the first pole ear as the positive pole ear of the electrode assembly, the first pole ear is used to output or input the positive electrode of the electrode assembly. Correspondingly, the collection pole ear is used to output the positive electrode of the electrode assembly, so that the wall is a positively charged structure when the information collection device collects data. The battery cell with this structure can effectively alleviate the phenomenon of electrical corrosion on the outer shell of the battery cell, which is beneficial to improve the service life of the battery cell and reduce the risk of leakage of the battery cell during use.

[0048] In some embodiments, the battery cell further includes a second electrode terminal, which is insulated and mounted on the outer shell; wherein the electrode assembly further includes a second pole tab, which is arranged on the main body, the second pole tab is electrically connected to the second electrode terminal, and the polarity of the second pole tab is opposite to that of the first pole tab.

[0049] In the above technical solution, the battery cell is also provided with a second electrode terminal, and correspondingly, the electrode assembly also includes a second pole ear, the polarity of the second pole ear is opposite to the polarity of the first pole ear, and the second pole ear is electrically connected to the second electrode terminal, so that the first electrode terminal and the second electrode terminal cooperate to input or output the positive and negative poles of the battery cell, wherein, by insulating the second electrode terminal and installing it on the outer shell, it is helpful to reduce the risk of short circuit between the second electrode terminal and the collection pole ear.

[0050] In some embodiments, the housing includes a shell and an end cover; a receiving cavity with an opening is formed inside the shell, and the receiving cavity is used to receive the electrode assembly; the end cover closes the opening; wherein the end cover is the wall portion.

[0051] In the above technical solution, by setting the wall portion of the shell as the end cover for closing the opening of the shell, the battery cell adopting this structure facilitates the connection of the collection tab with the wall portion of the shell, which is beneficial to reduce the difficulty of assembling the battery cell and improve the production efficiency of the battery cell.

[0052] In some embodiments, the outer shell includes a shell and an end cover; the shell includes an integrally formed side wall and the wall portion, the side wall is arranged around the wall portion, and along the thickness direction of the wall portion, one end of the side wall is connected to the wall portion, and the other end is enclosed to form an opening, and the side wall and the wall portion jointly define a accommodating cavity for accommodating the electrode assembly; the end cover closes the opening.

[0053] In the above technical solution, by setting the wall portion of the outer shell as a wall of the shell that is arranged opposite to the end cover in the thickness direction of the wall portion, the battery cell using this structure can make the wall portion used to be connected to the collection pole ear away from the end cover, so that there is no direct connection relationship between the wall portion and the end cover, thereby alleviating the influence of the stress generated by the mutual assembly between the end cover and the shell on the collection pole ear, which is beneficial to improving the service life of the collection pole ear, and can alleviate the phenomenon that the force generated by other components pulling or twisting the wall portion acts on the end cover, so as to reduce the risk of connection failure between the end cover and the shell, and further help to further reduce the risk of leakage of the battery cell during use.

[0054] In a second aspect, an embodiment of the present application further provides a battery comprising the above-mentioned battery cell.

[0055] In some embodiments, the battery further includes a battery management system; the battery management system is electrically connected to the wall portion, and the battery management system is configured to issue an early warning when the collection tab is blown.

[0056] In the above technical solution, the battery is also provided with a battery management system, which is electrically connected to the wall, and the battery management system can issue an early warning after a short circuit occurs in the battery cell and causes the collection tab to melt, so as to provide an early warning to the operator or user, thereby reducing the further damage or impact caused by the short circuit of the battery cell to the operator or user, which is conducive to improving the reliability of the battery.

[0057] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery cell, wherein the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0059] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0060] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0061] FIG3 is a schematic structural diagram of a battery cell provided in some embodiments of the present application;

[0062] FIG4 is an exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0063] FIG5 is a cross-sectional view of a battery cell provided in some embodiments of the present application;

[0064] FIG6 is a partial enlarged view of the battery cell at point A shown in FIG5 ;

[0065] FIG7 is a schematic structural diagram of an electrode assembly of a battery cell provided in some embodiments of the present application;

[0066] FIG8 is a partial enlarged view of point B of the electrode assembly shown in FIG7 ;

[0067] FIG9 is a front view of an electrode assembly of a battery cell provided in some embodiments of the present application;

[0068] FIG10 is a partial enlarged view of a portion C of the electrode assembly shown in FIG9 .

[0069] Icon: 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery cell; 21-housing; 211-wall; 212-housing; 2121-opening; 213-end cover; 22-first electrode terminal; 23-electrode assembly; 231-main body; 232-first tab; 233-collecting tab; 2331-weak section; 2332-groove; 2333-first connecting section; 23331-first connecting section; 2 3331a-first surface; 23331b-second surface; 23332-second connecting portion; 2334-second connecting section; 234-second electrode tab; 24-first current collecting member; 241-first protrusion; 25-second electrode terminal; 26-second current collecting member; 261-second protrusion; 27-insulating member; 271-avoidance hole; 28-pressure relief mechanism; 29-weld stamp; 200-controller; 300-motor; X-thickness direction of the wall; Y-first direction; Z-second direction. DETAILED DESCRIPTION

[0070] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts 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 meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0072] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0073] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0074] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0075] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0076] The term "plurality" used in this application refers to two or more (including two).

[0077] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0078] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0079] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the 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 electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0082] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may 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-containing phosphates, lithium transition metal oxides and their respective modified compounds. However, the present application is not limited to these materials, and other traditional 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. Among them, examples of lithium-containing phosphates may include but are not limited to at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides 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, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3O2 (also referred to as NCM 333 ), LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 ), LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 ), LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 ), LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and at least one of its modified compounds, etc.

[0084] In some embodiments, a positive electrode may utilize a metal foam. The metal foam may include nickel foam, copper foam, aluminum foam, alloy foam, or the like. When a metal foam is used as the positive electrode, the surface of the metal foam may or may not include a positive electrode active material. For example, a lithium source material, potassium metal, or sodium metal may be filled or / and deposited within the metal foam, 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 may be a metal foil, a metal foam, or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, nickel, or titanium, etc. may be used. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, etc. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[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 facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0089] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells that is well known in the art. 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, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries 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 material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0091] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0092] In some embodiments, the separator is a separator membrane. There are many types of separator membranes, and any known separator membrane with a porous structure having good chemical stability and mechanical stability can be selected.

[0093] As an example, the separator can be made of at least one of fiberglass, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator can be a single-layer film or a multi-layer composite film. In the case of a multi-layer composite film, the materials of each layer can be the same or different. The separator can be a separate component positioned between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0094] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0095] In some embodiments, the battery cell further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel, or solid. Liquid electrolytes include an electrolyte salt and a solvent.

[0096] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium bisoxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0097] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methylpropyl carbonate, ethylpropyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

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

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

[0100] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, or the like.

[0101] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0102] As an example, a composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0103] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0104] In some embodiments, the electrode assembly is a laminate structure.

[0105] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0106] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0107] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0108] As an example, a plurality of separators may be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets.

[0109] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

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

[0111] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0112] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0113] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include but are not limited to square-shell, blade-shaped, and polygonal batteries, such as hexagonal batteries.

[0114] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0115] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0116] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0117] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0118] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0119] Batteries, with their outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient, are a vital component of today's new energy development. The development of battery technology requires simultaneous consideration of multiple design factors, including performance parameters such as energy density, cycle life, discharge capacity, and charge / discharge rate. Furthermore, battery safety must also be considered.

[0120] For a general battery cell, the battery cell usually includes a shell, an electrode assembly and two electrode terminals. The electrode assembly is accommodated in the shell, and the two electrode terminals are both arranged on the shell. The two electrode terminals are respectively connected to the positive and negative tabs of the electrode assembly to realize the input or output of the positive and negative electrodes of the battery cell. By connecting the information collection device to the electrode terminals, the usage of the battery cell can be monitored. In order to reduce the difficulty of connecting the information collection device and the battery cell and reduce the difficulty of data collection, in the related art, the shell of the battery cell is usually connected to one tab of the electrode assembly so that the shell of the battery cell is positively or negatively charged. In this way, the usage information of the battery cell can be collected by connecting the information collection device to the shell of the battery cell, which is conducive to reducing the difficulty of assembling and arranging the information collection device. However, the battery cell of this structure is very likely to have the tabs of different polarities overlap with the shell, resulting in the risk of overlapping short circuit of the battery cell, which is very likely to cause damage to the information collection device and make the battery cell have a greater risk of use, which is not conducive to improving the reliability of the battery cell.

[0121] Based on the above considerations, in order to solve the problem of low reliability of battery cells, an embodiment of the present application provides a battery cell, which includes a housing, a first electrode terminal, and an electrode assembly. The housing has a wall portion. The first electrode terminal is insulated and mounted on the housing. The electrode assembly is accommodated in the housing, and the electrode assembly includes a main body and a first electrode tab, the first electrode tab being arranged on the main body and electrically connected to the first electrode terminal. The electrode assembly also includes a collection tab, which is arranged on the main body, has the same polarity as the first electrode tab, is electrically connected to the wall portion, and has a minimum flow area smaller than the minimum flow area of ​​the first electrode tab.

[0122] In a battery cell of this structure, a collecting tab with the same polarity as the first tab is provided on the electrode assembly. By electrically connecting the collecting tab to the wall of the shell, the positive or negative pole of the electrode assembly can be electrically connected to the shell, so that the information collection device can collect the usage information of the battery cell after being electrically connected to the shell, thereby facilitating the information collection device to connect the battery cell and collect data, which is conducive to reducing the difficulty of data collection for the battery cell. Among them, by setting the minimum flow area of ​​the collecting tab to be smaller than the minimum flow area of ​​the first tab, so that the minimum cross-sectional area of ​​the collecting tab on the path through which current passes is smaller than the minimum cross-sectional area of ​​the first tab on the path through which current passes. area, so that the resistance of the collection ear at the minimum flow area is greater than the resistance of the first ear, so that within the same time, the heat generated by the collection ear when the electrode assembly inside the battery cell and the shell are overlapped and short-circuited is higher and the heat accumulates faster, so that the collection ear can be melted first compared to the first ear when the electrode assembly inside the battery cell and the shell are overlapped and short-circuited, so that the battery cell can disconnect the electrical connection between the collection ear and the shell after a short circuit occurs, and then cut off the short-circuit path, so as to alleviate the damage of the information collection equipment, and can effectively reduce the further use risk caused by the battery cell, which is conducive to improving the reliability of the battery cell.

[0123] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to construct such electrical devices. This helps mitigate the risks of internal short circuits in the battery cells, thereby improving the reliability of the battery cells.

[0124] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0125] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device according to an embodiment of the present application.

[0126] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 can be arranged at the bottom of the vehicle 1000, or at the head of the vehicle 1000, or at the tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can be used as an operating power source or a power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, for starting, navigating and driving the vehicle 1000.

[0127] In some embodiments of the present application, the battery 100 can not only serve as the operating power source or usage power source of the vehicle 1000, but also serve as the driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0128] 2 and 3 , FIG2 is an exploded view of a battery 100 according to some embodiments of the present invention, and FIG3 is a schematic diagram of a battery cell 20 according to some embodiments of the present invention. The battery 100 includes a housing 10 and a battery cell 20 , wherein the battery cell 20 is accommodated in the housing 10 .

[0129] The housing 10 is used to provide assembly space for the battery cells 20 and can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12. The first housing body 11 and the second housing body 12 cover each other, and the first housing body 11 and the second housing body 12 jointly define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-like structure. The first housing body 11 covers the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define the assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, and the open side of the first housing body 11 covers the open side of the second housing body 12.

[0130] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid or a cube, etc. For example, in FIG2 , the box body 10 is in the shape of a cuboid.

[0131] In the battery 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, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel configurations within the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure formed by the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 can be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single structure, which is then housed within the housing 10.

[0132] In some embodiments, the battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which is used to connect the multiple battery cells 20 to achieve electrical connection between the multiple battery cells 20 .

[0133] 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 thereto. The battery cell 20 can be a rectangular parallelepiped, a cylinder, a prism, or other shapes. For example, in FIG3 , the battery cell 20 is a rectangular parallelepiped.

[0134] According to some embodiments of the present application, referring to FIG3 and further referring to FIG4, FIG5, FIG6 and FIG7, FIG4 is an exploded view of the structure of a battery cell 20 provided in some embodiments of the present application, FIG5 is a cross-sectional view of a battery cell 20 provided in some embodiments of the present application, FIG6 is a partial enlarged view of the battery cell 20 at A shown in FIG5, and FIG7 is a schematic structural diagram of an electrode assembly 23 of a battery cell 20 provided in some embodiments of the present application. The present application provides a battery cell 20, which includes a housing 21, a first electrode terminal 22 and an electrode assembly 23. The housing 21 has a wall portion 211. The first electrode terminal 22 is insulated and mounted to the housing 21. The electrode assembly 23 is accommodated in the housing 21 and includes a main body 231 and a first electrode tab 232. The first electrode tab 232 is provided on the main body 231 and is electrically connected to the first electrode terminal 22. The electrode assembly 23 also includes a collecting tab 233 , which is disposed on the main body 231 . The collecting tab 233 has the same polarity as the first tab 232 , is electrically connected to the wall 211 , and has a minimum flow area smaller than that of the first tab 232 .

[0135] The housing 21 can also be used to accommodate an electrolyte, such as an electrolyte solution. The housing 21 can have various structural forms. The housing 21 can also be made of various materials, such as copper, iron, aluminum, steel, and aluminum alloys.

[0136] In some embodiments, the housing 21 may include a shell 212 and an end cover 213, wherein a accommodating cavity is formed inside the shell 212, and the accommodating cavity has an opening 2121, that is, the shell 212 is a hollow structure with one end open, and the end cover 213 covers the opening 2121 of the shell 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 23 and the electrolyte.

[0137] Optionally, the wall portion 211 for connecting the collecting tab 233 may be the end cap 213, or may be one of the multiple walls of the housing 212. For example, in Figures 3 and 4, the wall portion 211 is the end cap 213 of the housing 21. Of course, in other embodiments, the wall portion 211 may also be the bottom wall of the housing 212 disposed opposite the end cap 213 in the thickness direction X of the wall portion, or a side wall adjacent to and abutting the end cap 213.

[0138] When assembling the battery cell 20 , the electrode assembly 23 may be placed in the housing 212 , and the housing 212 may be filled with electrolyte. The end cap 213 may then be placed on the opening 2121 of the housing 212 to seal the opening 2121 of the housing 212 .

[0139] Optionally, the housing 212 can have a variety of shapes, such as a cylinder, a rectangular parallelepiped, etc. 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 has a cylindrical structure, the housing 212 can have a cylindrical structure; if the electrode assembly 23 has a rectangular parallelepiped structure, the housing 212 can have a rectangular parallelepiped structure. Of course, the end cap 213 can also have a variety of structures, such as a plate-like structure or a hollow structure with one end open. For example, in Figure 4, the housing 212 has a rectangular parallelepiped structure and the end cap 213 has a plate-like structure.

[0140] It is understandable that the outer shell 21 is not limited to the above structure. The outer shell 21 may also be other structures. For example, the outer shell 21 includes a shell body 212 and two end covers 213. The shell body 212 is a hollow structure with openings 2121 on opposite sides. One end cover 213 corresponds to an opening 2121 of the shell body 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 23 and the electrolyte.

[0141] The electrode assembly 23 is a component in the battery cell 20 where electrochemical reactions occur. The structure of the electrode assembly 23 can be various. For example, the electrode assembly 23 can be a wound structure formed by winding the positive electrode sheet, the separator and the negative electrode sheet, or it can be a stacked structure formed by stacking the positive electrode sheet, the separator and the negative electrode sheet.

[0142] Illustratively, the separator is an isolation membrane, and a main material of the isolation membrane may be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, and polyvinylidene fluoride.

[0143] The electrode assembly 23 includes a main body 231 and a first tab 232. The first tab 232 is disposed on the main body 231. The main body 231 is the primary portion of the electrode assembly 23 where the electrochemical reaction occurs within the battery cell 20. The first tab 232 serves as the input or output for the positive or negative electrode of the electrode assembly 23. The first tab 232 is electrically connected to the first electrode terminal 22 to establish an electrical connection between the electrode assembly 23 and the first electrode terminal 22. It should be noted that the first tab 232 of the electrode assembly 23 is formed by laminating and connecting the regions of the positive electrode sheet not coated with the positive electrode active material layer, or by laminating and connecting the regions of the negative electrode sheet not coated with the negative electrode active material layer. If the first pole tab 232 is used to output the positive electrode of the electrode assembly 23, that is, the first pole tab 232 is the positive pole tab of the electrode assembly 23, then the first pole tab 232 is a component formed by mutually stacking and connecting the areas on the positive electrode sheet that are not coated with the positive electrode active material layer; if the first pole tab 232 is used to output the negative electrode of the electrode assembly 23, that is, the first pole tab 232 is the negative pole tab of the electrode assembly 23, then the first pole tab 232 is a component formed by mutually stacking and connecting the areas on the negative electrode sheet that are not coated with the negative electrode active material layer.

[0144] Optionally, the number of electrode assemblies 23 housed within the housing 21 may be one or more. For example, in FIG4 , the housing 21 of the battery cell 20 is provided with two electrode assemblies 23 , which are stacked along the second direction Z. The first direction Y, the second direction Z, and the thickness direction X of the wall portion are perpendicular to each other. The first direction Y is the length direction of the battery cell 20, the second direction Z is the thickness direction of the battery cell 20, and the thickness direction X of the wall portion is the height direction of the battery cell 20. Of course, in other embodiments, the number of electrode assemblies 23 housed within the housing 21 may be one, three, four, five, six, seven, or eight, etc.

[0145] In the embodiment of the present application, the first electrode terminal 22 plays the role of outputting or inputting electrical energy of the battery cell 20. One end of the first electrode terminal 22 is used to be electrically connected to the first electrode ear 232 of the electrode assembly 23, and the other end is used to be connected to the busbar component to realize the input or output of electrical energy of the battery cell 20.

[0146] Optionally, the connection structure between the first electrode terminal 22 and the first electrode tab 232 can be various. The first electrode terminal 22 can be directly connected to the first electrode tab 232, for example, the first electrode terminal 22 and the first electrode tab 232 are welded or abutted, etc. Of course, the first electrode terminal 22 can also be indirectly connected to the first electrode tab 232, for example, the first electrode terminal 22 is welded or abutted with other components and then connected to the first electrode tab 232.

[0147] It should be noted that the first electrode terminal 22 is insulated and mounted on the outer shell 21. In other words, there is no electrical connection between the first electrode terminal 22 and the outer shell 21. The first electrode terminal 22 can be provided on the outer shell 21 in various structures. The first electrode terminal 22 can be mounted on the end cap 213 or on the housing 212. For example, in Figures 3 and 4, the first electrode terminal 22 is insulated and mounted on the end cap 213, that is, the first electrode terminal 22 is insulated and mounted on the wall 211 of the outer shell 21.

[0148] For example, the first electrode terminal 22 may be made of various materials. For example, the first electrode terminal 22 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0149] In some embodiments, as shown in Figure 4, the battery cell 20 may further include a first current collecting member 24, which is disposed in the outer shell 21. The first current collecting member 24 connects the first electrode terminal 22 and the first electrode tab 232 of the electrode assembly 23 to achieve electrical connection between the electrode assembly 23 and the first electrode terminal 22.

[0150] 4 , the first current collecting member 24 is provided with a first protrusion 241 on one side facing the wall portion 211 in the thickness direction X of the wall portion. The first protrusion 241 is used to be connected to the first electrode terminal 22 to electrically connect the first current collecting member 24 and the first electrode terminal 22. The first current collecting member 24 with such a structure is conducive to reducing the difficulty of connecting the first current collecting member 24 and the first electrode terminal 22.

[0151] Illustratively, the first protrusion 241 of the first current collecting member 24 is welded to the first electrode terminal 22, and the first current collecting member 24 is welded to the first electrode tab 232. Of course, in other embodiments, the first protrusion 241 of the first current collecting member 24 may also be in abutment with the first electrode terminal 22, and similarly, the first current collecting member 24 may also be in abutment with the first electrode tab 232.

[0152] The first current collecting member 24 connects the first electrode terminal 22 and the first tab 232 of the electrode assembly 23 . The first current collecting member 24 can be made of various materials, for example, copper, iron, aluminum, steel, aluminum alloy, etc.

[0153] In Figure 4, the battery cell 20 may further include a second electrode terminal 25 and a second current collecting member 26. The second electrode terminal 25 is insulated and mounted on the outer shell 21. The second current collecting member 26 is arranged between the main body 231 and the wall 211 along the thickness direction X of the wall. Correspondingly, the electrode assembly 23 also includes a second pole tab 234. The second pole tab 234 is arranged on the main body 231, and the polarity of the second pole tab 234 is opposite to the polarity of the first pole tab 232, that is, the polarity of the second pole tab 234 is also opposite to the polarity of the collecting pole tab 233. That is, if the first pole tab 232 is the positive pole tab of the electrode assembly 23, then the second pole tab 234 is the negative pole tab of the electrode assembly 23. If the first pole tab 232 is the negative pole tab of the electrode assembly 23, then the second pole tab 234 is the positive pole tab of the electrode assembly 23. The second electrode tab 234 is connected to the second electrode terminal 25 through the second current collecting member 26 , so that the first electrode terminal 22 and the second electrode terminal 25 input or output the positive electrode and the negative electrode of the battery cell 20 , respectively.

[0154] Among them, the structure of the second electrode terminal 25 set on the outer shell 21 can be various. The second electrode terminal 25 can be installed on the end cover 213 or on the shell 212. For example, in Figures 3 and 4, the second electrode terminal 25 is insulated and installed on the end cover 213, that is, the second electrode terminal 25 is insulated and installed on the wall 211 of the outer shell 21.

[0155] Exemplarily, the first pole tab 232, the second pole tab 234 and the collecting pole tab 233 are all arranged at one end of the main body 231 facing the end cover 213 in the thickness direction X of the wall portion, and the first pole tab 232 and the second pole tab 234 are arranged at intervals along the first direction Y, and the collecting pole tab 233 is located between the first pole tab 232 and the second pole tab 234 in the first direction Y, so that the first pole tab 232 and the second pole tab 234 are electrically connected to the first electrode terminal 22 and the second electrode terminal 25 respectively, and the collecting pole tab 233 is electrically connected to the end cover 213 serving as the wall portion 211.

[0156] Optionally, as shown in Figure 4, the second current collecting member 26 is provided with a second protrusion 261 on the side facing the wall portion 211 in the thickness direction X of the wall portion. The second protrusion 261 is used to be connected to the second electrode terminal 25 to electrically connect the second current collecting member 26 and the second electrode terminal 25. The second current collecting member 26 with this structure is conducive to reducing the difficulty of connecting the second current collecting member 26 and the second electrode terminal 25.

[0157] Illustratively, the second protrusion 261 of the second current collecting member 26 is welded to the second electrode terminal 25, and the second current collecting member 26 is welded to the second electrode tab 234. Of course, in other embodiments, the second protrusion 261 of the second current collecting member 26 may also be in abutment with the second electrode terminal 25, and similarly, the second current collecting member 26 may also be in abutment with the second electrode tab 234.

[0158] The electrode assembly 23 also includes a collection tab 233, which connects the main body 231 and the wall 211. This allows the wall 211 of the battery cell 20 to carry the same charge as the first tab 232, thereby facilitating the acquisition of battery cell 20 usage information by the information collection device after it is connected to the housing 21. It should be noted that when the information collection device needs to collect data on the usage of the battery cell 20, the two input terminals of the information collection device are connected to the wall 211 of the housing 21 and the second electrode terminal 25, respectively, to collect battery cell 20 usage data.

[0159] There may be various connection structures between the collecting tab 233 and the wall portion 211 . For example, the collecting tab 233 may be connected to the wall portion 211 by welding, abutting, or other structures.

[0160] The collecting tab 233 has the same polarity as the first tab 232, that is, the charge carried by the collecting tab 233 is the same as the charge carried by the first tab 232. Optionally, the collecting tab 233 can be the positive electrode of the output electrode assembly 23 or the negative electrode of the output electrode assembly 23. The collecting tab 233 is a component formed by stacking and connecting the regions of the electrode sheets with the same polarity as the first tab 232 that are not coated with the active material layer. If the first tab 232 is the positive tab of the electrode assembly 23, the collecting tab 233 is a component formed by stacking and connecting the regions of the positive electrode sheets that are not coated with the positive active material layer. If the first tab 232 is the negative tab of the electrode assembly 23, the collecting tab 233 is a component formed by stacking and connecting the regions of the negative electrode sheets that are not coated with the negative active material layer. Exemplarily, the first tab 232 is the positive tab of the electrode assembly 23, and correspondingly, the collecting tab 233 is used for the positive electrode of the output electrode assembly 23.

[0161] The minimum flow area of ​​the collecting electrode tab 233 refers to the minimum cross-sectional area of ​​the collecting electrode tab 233 for current to pass through on the flow path of the current flowing from the main body 231 through the collecting electrode tab 233 to the wall portion 211 or from the wall portion 211 through the collecting electrode tab 233 to the main body 231. That is to say, in the direction in which the current flows through the collecting electrode tab 233, the area of ​​the minimum cross section of the collecting electrode tab 233 perpendicular to the direction of current flow is the minimum flow area of ​​the collecting electrode tab 233.

[0162] Among them, the position of the minimum flow area of ​​the collecting pole ear 233 can be determined by tomography, that is, the position of the minimum cross-section of the collecting pole ear 233 perpendicular to the flow direction of the current can be determined by tomography, and the area of ​​the minimum cross-section of the collecting pole ear 233 perpendicular to the flow direction of the current can be determined, that is, the minimum flow area of ​​the collecting pole ear 233. In other words, the minimum flow area of ​​the collecting pole ear 233 is also obtained by tomography.

[0163] The minimum flow area of ​​the first pole tab 232 refers to the minimum cross-sectional area of ​​the first pole tab 232 for current to pass through on the flow path of the current flowing from the main body 231 through the first pole tab 232 to the first electrode terminal 22 or from the first electrode terminal 22 through the first pole tab 232 to the main body 231. That is, in the direction in which the first pole tab 232 supplies current to flow, the area of ​​the minimum cross-section of the first pole tab 232 perpendicular to the direction of current flow is the minimum flow area of ​​the first pole tab 232.

[0164] Among them, the position of the minimum flow area of ​​the first pole lug 232 can be determined by tomography, that is, the position of the minimum cross-section of the first pole lug 232 perpendicular to the flow direction of the current can be determined by tomography, and the area of ​​the minimum cross-section of the first pole lug 232 perpendicular to the flow direction of the current can be determined, that is, the minimum flow area of ​​the first pole lug 232. In other words, the minimum flow area of ​​the first pole lug 232 is also obtained by tomography.

[0165] The minimum flow area of ​​the collecting tab 233 is smaller than the minimum flow area of ​​the first tab 232 , that is, in the current flow path, the minimum cross-sectional area of ​​the collecting tab 233 for current to pass through is smaller than the minimum cross-sectional area of ​​the first tab 232 for current to pass through.

[0166] It should be noted that, in the current flow path, the area of ​​the minimum cross section of the collecting tab 233 for current to pass through is smaller than the area of ​​the minimum cross section of the first tab 232 for current to pass through. According to the resistance formula (R=ρL / S), the resistance of the collecting tab 233 at the minimum flow area is greater than the resistance of the first tab 232. When the second tab 234 of the electrode assembly 23 overlaps with the shell 21 to cause a short circuit in the battery cell 20, according to the heat formula (Q=I 2Rt) shows that, within the same time, the heat generated by the collecting pole ear 233 at the minimum flow area is higher than that of the first pole ear 232, and the heat accumulation speed is faster than that of the first pole ear 232. As a result, when the second pole ear 234 and the shell 21 overlap with each other and cause a short circuit in the battery cell 20, the collecting pole ear 233 will take precedence over and be more likely to fuse than the first pole ear 232, so that when a short circuit occurs in the battery cell 20, the electrical connection between the collecting pole ear 233 and the wall 211 of the shell 21 can be disconnected, thereby cutting off the short circuit path and alleviating the use risk further caused by the short circuit of the battery cell 20.

[0167] For example, in FIG4 , only one of the two electrode assemblies 23 is provided with a collecting tab 233 . Of course, in other embodiments, each electrode assembly 23 may be provided with a collecting tab 233 , and the polarity of the collecting tab 233 of each electrode assembly 23 may be the same.

[0168] In some embodiments, referring to Figures 4, 5 and 6, the battery cell 20 may further include an insulating member 27. Along the thickness direction X of the wall portion, the insulating member 27 is arranged on the side of the wall portion 211 facing the electrode assembly 23. The insulating member 27 is configured to insulate and isolate the wall portion 211 and the main body 231 of the electrode assembly 23 to reduce the risk of short circuit between the main body 231 of the electrode assembly 23 and the wall portion 211.

[0169] The insulating member 27 is provided with an avoidance hole 271 for the collecting tab 233 to pass through. The avoidance hole 271 passes through both sides of the insulating member 27 along the thickness direction X of the wall. The collecting tab 233 is inserted into the avoidance hole 271 and connected to the wall 211.

[0170] Exemplarily, the insulating member 27 can be made of various materials, such as rubber, silicone, or plastic.

[0171] In some embodiments, as shown in Figures 3 and 4, the battery cell 20 may further include a pressure relief mechanism 28, which is provided on the housing 21 and 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.

[0172] Optionally, the pressure relief mechanism 28 may be provided on the end cover 213 of the housing 21 or on the shell 212 of the housing 21. For example, in FIG3 and FIG4 , the pressure relief mechanism 28 is provided on the end cover 213.

[0173] Similarly, the pressure relief mechanism 28 and the housing 21 can be integrally formed or separately formed. For example, in FIG4 , the pressure relief mechanism 28 and the housing 21 are separate structures, and the pressure relief mechanism 28 can be connected to the housing 21 by welding or other methods. Accordingly, the pressure relief mechanism 28 can be a pressure relief component such as an explosion-proof valve, explosion-proof disk, air valve, pressure relief valve, or safety valve. Of course, in other embodiments, the pressure relief mechanism 28 and the housing 21 can also be integrally formed, in which case the pressure relief mechanism 28 is an area of ​​the housing 21 where a weak structure is formed, such as an area of ​​the housing 21 where a notched groove is provided.

[0174] In this embodiment, a collecting tab 233 having the same polarity as the first tab 232 is provided on the electrode assembly 23. By electrically connecting the collecting tab 233 to the wall 211 of the shell 21, the positive or negative pole of the electrode assembly 23 can be electrically connected to the shell 21, so that the information collection device can collect usage information of the battery cell 20 after being electrically connected to the shell 21, thereby facilitating the information collection device to connect to the battery cell 20 and perform data collection, which is conducive to reducing the difficulty of data collection for the battery cell 20. Specifically, by setting the minimum flow area of ​​the collecting tab 233 to be smaller than the minimum flow area of ​​the first tab 232, the minimum cross-sectional area of ​​the collecting tab 233 on the path for current passage is smaller than the minimum cross-sectional area of ​​the first tab 232 on the path for current passage. The collection tab 233 has a larger resistance than the first tab 232 at the minimum flow area, so that within the same time, the heat generated by the collection tab 233 when the electrode assembly 23 inside the battery cell 20 and the shell 21 overlap and short-circuit occurs is higher and the heat accumulates faster, so that the collection tab 233 can be melted preferentially compared with the first tab 232 when the electrode assembly 23 inside the battery cell 20 and the shell 21 overlap and short-circuit occurs, so that the battery cell 20 can disconnect the electrical connection between the collection tab 233 and the shell 21 after a short circuit occurs, and then cut off the short-circuit path, so as to alleviate the damage of the information collection equipment, and can effectively reduce the risk of further use of the battery cell 20, which is conducive to improving the reliability of the battery cell 20.

[0175] According to some embodiments of the present application, the minimum flow area of ​​the collecting tab 233 is S1, which satisfies 2mm 2 ≤S1≤20mm 2 That is to say, on the path of the current flowing through the collecting tab 233, the minimum cross-sectional area of ​​the collecting tab 233 perpendicular to the current flow direction is 2 mm 2 Up to 20mm 2 .

[0176] For example, the minimum flow area S1 of the collecting tab 233 may be 2 mm 2, 2.1mm 2 , 2.2mm 2 , 2.5mm 2 , 3mm 2 , 3.5mm 2 , 4mm 2 、 5mm 2 , 6mm 2 , 7mm 2 , 8mm 2 , 9mm 2 , 10mm 2 , 11mm 2 , 12mm 2 , 15mm 2 , 16mm 2 , 18mm 2 or 20mm 2 wait.

[0177] In this embodiment, the minimum flow area of ​​the collecting tab 233 is set to 2mm 2 Up to 20mm 2 On the one hand, the minimum flow area of ​​the collecting tab 233 is set to be greater than or equal to 2mm 2 , in order to improve the structural strength of the collecting tab 233, thereby reducing the risk of the collecting tab 233 being accidentally broken during use, which is beneficial to improving the service life and stability of the battery cell 20. On the other hand, the minimum flow area of ​​the collecting tab 233 is set to be less than or equal to 20mm 2 , in order to alleviate the phenomenon that the collection tab 233 takes too long to melt when a short circuit occurs in the battery cell 20, and make the collection tab 233 easier to melt, so that the collection tab 233 can be quickly melted when a short circuit occurs in the battery cell 20 to cut off the short circuit path, thereby further alleviating the phenomenon of damage to the information collection equipment and further improving the reliability of the battery cell 20. Therefore, the minimum flow area of ​​the collection tab 233 is set to 2mm 2 Up to 20mm 2 , while ensuring that the collecting tab 233 has sufficient strength during use, it can also achieve rapid melting of the collecting tab 233 when a short circuit occurs in the battery cell 20.

[0178] According to some embodiments of the present application, referring to Figures 5, 6 and 7, and further referring to Figure 8, Figure 8 is a local enlarged view of point B of the electrode assembly 23 shown in Figure 7, and a portion of the collecting tab 233 forms a weak section 2331, and the minimum flow area of ​​the weak section 2331 is the minimum flow area S1 of the collecting tab 233.

[0179] Part of the collecting tab 233 forms a weak section 2331. Specifically, a weak section 2331 is formed in the direction of extension of the collecting tab 233 or along the path through which current flows through the collecting tab 233. This allows the wall portion 211 and the main body 231 to be electrically connected via the weak section 2331 of the collecting tab 233. Current flowing between the wall portion 211 and the main body 231 passes through the weak section 2331 of the collecting tab 233, resulting in the cross-sectional area of ​​the weak section 2331 perpendicular to the direction of extension of the collecting tab 233 being the minimum flow area S1 of the collecting tab 233. In other words, the weak section 2331 of the collecting tab 233 represents the minimum flow area of ​​the collecting tab 233, and the cross-sectional area of ​​the weak section 2331 perpendicular to the direction of extension of the collecting tab 233 is the minimum flow area of ​​the collecting tab 233.

[0180] It should be noted that the extension direction of the collecting pole ear 233 is the extension direction from one end of the collecting pole ear 233 connected to the main body 231 to the end of the collecting pole ear 233 away from the main body 231, or the extension direction from one end of the collecting pole ear 233 away from the main body 231 to the end of the collecting pole ear 233 connected to the main body 231. At the same time, the extension direction of the collecting pole ear 233 is also the direction in which the current flows through the collecting pole ear 233.

[0181] Optionally, in FIG8 , a groove 2332 is provided on one side of the collecting tab 233 in the first direction Y. The groove 2332 extends through both sides of the collecting tab 233 in the thickness direction, thereby forming a weak section 2331 on the bottom wall of the groove 2332. Exemplarily, the collecting tab 233 is provided with grooves 2332 on both sides in the first direction Y, such that the weak section 2331 is formed between the bottom surfaces of the two grooves 2332. In other words, the portion of the collecting tab 233 located between the bottom surfaces of the two grooves 2332 constitutes the weak section 2331. Of course, in other embodiments, the collecting tab 233 may also be provided with the groove 2332 on only one side in the first direction Y, thereby forming the weak section 2331 on the bottom wall of the groove 2332.

[0182] In this embodiment, a weak section 2331 is formed on the collecting tab 233 so that the minimum flow area of ​​the weak section 2331 of the collecting tab 233 is the minimum flow area of ​​the collecting tab 233, so that when a short circuit occurs in the battery cell 20, the weak section 2331 of the collecting tab 233 can be fused. On the one hand, by providing the weak section 2331 on the collecting tab 233, the minimum flow area of ​​the collecting tab 233 can be made smaller than the minimum flow area of ​​the first tab 232, which has a simple structure and is easy to manufacture. On the other hand, the fusing position of the collecting tab 233 can be controlled, and the fusing position can be controlled in the area where the weak section 2331 is located, so as to facilitate the assembly of the collecting tab 233 and avoid the weak section 2331 during the assembly process, which is beneficial to reducing the difficulty of assembling the collecting tab 233.

[0183] According to some embodiments of the present application, referring to Figures 7 and 8, and further referring to Figures 9 and 10, Figure 9 is a front view of an electrode assembly 23 of a battery cell 20 provided in some embodiments of the present application, and Figure 10 is a partial enlarged view of a portion C of the electrode assembly 23 shown in Figure 9. Along the extension direction of the collecting tab 233, the length of the weak section 2331 is L, satisfying the condition 0.3 mm ≤ L ≤ 5 mm.

[0184] The length L of the weak section 2331 refers to the length L of the weak section 2331 along the path for current flow in the collecting tab 233. For example, in Figures 8 and 10, the collecting tab 233 includes a first connecting section 2333, a weak section 2331, and a second connecting section 2334 connected in sequence. The groove 2332 is formed between the first connecting section 2333 and the second connecting section 2334. The first connecting section 2333 is used to connect to the wall portion 211, and the second connecting section 2334 is connected to the main body 231. The length L of the weak section 2331 refers to the length of the portion of the collecting tab 233 connected between the first connecting section 2333 and the second connecting section 2334.

[0185] Exemplarily, the length L of the weak section 2331 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.8mm, 2mm, 2.2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm or 5mm, etc.

[0186] In this embodiment, by setting the length of the weak section 2331 in the extension direction of the collecting tab 233 to 0.3 mm to 5 mm, on the one hand, the length of the weak section 2331 is set to be greater than or equal to 0.3 mm, so that the collecting tab 233 has sufficient space to fuse when a short circuit occurs in the battery cell 20, thereby effectively reducing the phenomenon of incorrect overlap of the weak section 2331 of the collecting tab 233 after melting, thereby reducing the overlap risk of the collecting tab 233 after melting, and on the other hand, the length of the weak section 2331 is set to be greater than or equal to 0.3 mm. The length is set to be less than or equal to 5 mm to alleviate the phenomenon of excessive space occupied by the weak section 2331 and the redundancy of the collecting tab 233, thereby improving the internal space utilization of the battery cell 20. Therefore, the length of the weak section 2331 in the extension direction of the collecting tab 233 is set to 0.3 mm to 5 mm, which can reduce the risk of incorrect overlap after the weak section 2331 of the collecting tab 233 is melted, and can also effectively save the space occupied by the weak section 2331 of the collecting tab 233.

[0187] According to some embodiments of the present application, as shown in Figures 6, 7 and 8, the collecting tab 233 may further include a first connecting segment 2333, the minimum flow area of ​​the first connecting segment 2333 is greater than the minimum flow area of ​​the weak segment 2331, and the first connecting segment 2333 connects the wall portion 211 and the weak segment 2331.

[0188] The minimum flow area of ​​the first connecting section 2333 is greater than the minimum flow area of ​​the weak section 2331 , that is, in the extension direction of the collecting tab 233 , the cross-sectional area of ​​the first connecting section 2333 is greater than the cross-sectional area of ​​the weak section 2331 .

[0189] In this embodiment, the collecting pole ear 233 is further provided with a first connecting section 2333, so that the weak section 2331 of the collecting pole ear 233 is a structure connected to the wall portion 211 through the first connecting section 2333, and the minimum flow area of ​​the first connecting section 2333 is greater than the minimum flow area of ​​the weak section 2331, so that the collecting pole ear 233 can be fused at the weak section 2331 while also being able to improve the connection area and connection reliability between the collecting pole ear 233 and the wall portion 211 through the structure connected to the wall portion 211 by the first connecting section 2333, which is conducive to improving the flow area between the collecting pole ear 233 and the wall portion 211.

[0190] According to some embodiments of the present application, as shown in Figures 6 and 8, the first connecting section 2333 may include a first connecting portion 23331 and a second connecting portion 23332, the first connecting portion 23331 is connected to the wall portion 211, the second connecting portion 23332 connects the first connecting portion 23331 and the weak section 2331, and the second connecting portion 23332 does not contact the wall portion 211.

[0191] Among them, the second connection part 23332 connects the first connection part 23331 and the weak section 2331, and the second connection part 23332 does not contact the wall part 211, that is, the first connection part 23331, the second connection part 23332 and the weak section 2331 are connected in sequence, the first connection part 23331 is connected to the wall part 211, and the second connection part 23332 in the first connection section 2333 that is interconnected with the weak section 2331 is a structure that does not contact the wall part 211, that is, the second connection part 23332 is a suspended structure.

[0192] In this embodiment, the first connecting section 2333 of the collecting tab 233 includes a first connecting portion 23331 and a second connecting portion 23332 that are connected to each other. The first connecting portion 23331 and the second connecting portion 23332 are respectively connected to the wall portion 211 and the weak section 2331, so that the weak section 2331 is a structure connected to the wall portion 211 after passing through the second connecting portion 23332 and the first connecting portion 23331 in sequence, and the second connecting portion 23332 does not contact the wall portion 211, so that the area where the first connecting section 2333 and the weak section 2331 are connected to each other is a part that does not contact the wall portion 211, thereby enabling the weak section 2331 of the collecting tab 233 to be a suspended structure, thereby effectively reducing the phenomenon that the weak section 2331 of the collecting tab 233 is accidentally overlapped with the wall portion 211 after melting, which is beneficial to reducing the risk of overlapping between the weak section 2331 of the collecting tab 233 and the wall portion 211 after melting.

[0193] In some embodiments, please continue to refer to Figures 6 and 8, the first connecting portion 23331 is welded to the wall portion 211, and along the thickness direction X of the wall portion, the first connecting portion 23331 has a first surface 23331a facing the wall portion 211 and a second surface 23331b away from the wall portion 211, the first surface 23331a is connected to the wall portion 211, and the first surface 23331a is a rough surface.

[0194] The first surface 23331a is a rough surface, that is, the first surface 23331a is a surface with a rough structure. For example, the first surface 23331a may be formed with structures such as embossing, bumps or ribs.

[0195] Optionally, the second surface 23331b may also be a rough surface, that is, the second surface 23331b may be a surface with a rough structure, for example, the second surface 23331b may be formed with structures such as embossing, bumps, or ribs.

[0196] It should be noted that in the embodiment in which the first connection portion 23331 is welded to the wall portion 211, the first connection portion 23331 may have only the first surface 23331a as a rough surface, or only the second surface 23331b as a rough surface, or both the first surface 23331a and the second surface 23331b as rough surfaces.

[0197] In this embodiment, the first connection portion 23331 of the first connection section 2333 is connected to the wall portion 211 through a welding connection structure, which is beneficial to improving the connection reliability and connection stability between the first connection section 2333 and the wall portion 211, wherein, by setting the first surface 23331a of the first connection portion 23331 facing the wall portion 211 as a rough surface to improve the roughness of the first connection portion 23331, the welding reliability between the first connection portion 23331 and the wall portion 211 can be improved, which is beneficial to improving the welding quality of the first connection portion 23331 and the wall portion 211. Similarly, by setting the second surface 23331b of the first connection portion 23331 facing away from the wall portion 211 as a rough surface to improve the roughness of the first connection portion 23331, the welding reliability between the first connection portion 23331 and the wall portion 211 can be improved, which is beneficial to improving the welding quality of the first connection portion 23331 and the wall portion 211.

[0198] According to some embodiments of the present application, as shown in Figures 6 and 8, the collecting tab 233 may further include a second connecting segment 2334, the minimum flow area of ​​the second connecting segment 2334 is greater than the minimum flow area of ​​the weak segment 2331, and the second connecting segment 2334 connects the weak segment 2331 and the main body 231.

[0199] The minimum flow area of ​​the second connecting section 2334 is greater than the minimum flow area of ​​the weak section 2331 , that is, in the extension direction of the collecting tab 233 , the cross-sectional area of ​​the second connecting section 2334 is greater than the cross-sectional area of ​​the weak section 2331 .

[0200] In this embodiment, the collecting tab 233 is further provided with a second connecting section 2334, so that the weak section 2331 of the collecting tab 233 is a structure connected to the main body 231 of the electrode assembly 23 through the second connecting section 2334, and the minimum flow area of ​​the second connecting section 2334 is greater than the minimum flow area of ​​the weak section 2331, so that the collecting tab 233 can be fused in the weak section 2331 while also being able to improve the connection area and connection reliability between the collecting tab 233 and the main body 231 through the structure connected to the main body 231 through the second connecting section 2334, which is beneficial to improving the flow area between the collecting tab 233 and the main body 231.

[0201] In some embodiments, as shown in FIG8 , the collecting tab 233 may further include a first connecting segment 2333. The first connecting segment 2333 includes a first connecting portion 23331 and a second connecting portion 23332. The first connecting portion 23331 is connected to the wall portion 211, and the second connecting portion 23332 connects the first connecting portion 23331 and the weak segment 2331, and the second connecting portion 23332 does not contact the wall portion 211. Along the extension direction of the collecting tab 233, the length of the second connecting portion 23332 is greater than the length of the second connecting segment 2334.

[0202] In the extension direction of the collecting tab 233, the length of the second connecting portion 23332 is greater than the length of the second connecting section 2334. In other words, in the arrangement direction in which the second connecting section 2334, the weak section 2331, the second connecting portion 23332, and the first connecting portion 23331 are sequentially connected, the size of the second connecting portion 23332 is greater than the size of the second connecting section 2334.

[0203] In this embodiment, the collecting tab 233 is further provided with a first connecting section 2333, and the first connecting section 2333 includes a first connecting portion 23331 and a second connecting portion 23332 connected to each other, the first connecting portion 23331 and the second connecting portion 23332 are respectively connected to the wall portion 211 and the weak section 2331, and the second connecting portion 23332 does not contact the wall portion 211, so that the area where the first connecting section 2333 and the weak section 2331 are connected to each other is a part that does not contact the wall portion 211, and by The length of the second connecting portion 23332 in the extension direction of the collecting pole ear 233 is set to be greater than the length of the second connecting section 2334 in the extension direction of the collecting pole ear 233, so as to realize a structure in which the weak section 2331 of the collecting pole ear 233 is suspended and away from the wall portion 211, thereby further reducing the phenomenon that the weak section 2331 of the collecting pole ear 233 is mistakenly overlapped with the wall portion 211 after melting, thereby further reducing the risk of overlap between the weak section 2331 of the collecting pole ear 233 and the wall portion 211 after melting.

[0204] According to some embodiments of the present application, as shown in Figures 4, 5, and 6, along the thickness direction X of the wall portion, the collecting tab 233 is disposed at one end of the main body 231 facing the wall portion 211. In other words, along the thickness direction X of the wall portion, the collecting tab 233 is located between the main body 231 and the wall portion 211.

[0205] It should be noted that in the embodiment where the collecting tab 233 is provided at one end of the main body 231 facing the wall 211 , the first tab 232 may be located at the same end of the main body 231 as the collecting tab 233 , or may be located at both ends of the main body 231 respectively.

[0206] In this embodiment, the collecting tab 233 is arranged at one end of the main body 231 facing the wall 211 in the thickness direction X of the wall, so that the collecting tab 233 is a structure arranged opposite to the wall 211 in the thickness direction X of the wall. On the one hand, the difficulty of assembling the collecting tab 233 and the wall 211 can be reduced, which is beneficial to improving the production efficiency of the battery cell 20. On the other hand, there is no need to excessively extend the collecting tab 233, which is beneficial to reducing the redundancy of the collecting tab 233, thereby reducing the risk of overlap between the collecting tab 233 and other components, and reducing the risk of the collecting tab 233 being inserted upside down into the main body 231 of the electrode assembly 23.

[0207] According to some embodiments of the present application, as shown in Figures 4 and 5 , the first electrode terminal 22 is insulated and mounted on the wall portion 211. Along the thickness direction X of the wall portion, the first electrode tab 232 is provided at one end of the main body portion 231 facing the wall portion 211. In other words, along the thickness direction X of the wall portion, the first electrode tab 232 is located between the main body portion 231 and the wall portion 211.

[0208] Exemplarily, the first electrode tab 232 and the collecting electrode tab 233 are both provided at one end of the main body 231 facing the wall 211 in the thickness direction X of the wall.

[0209] In this embodiment, the first electrode terminal 22 is insulated and installed on the wall portion 211, and the first pole tab 232 is arranged at one end of the main body 231 facing the wall portion 211 in the thickness direction X of the wall portion, so that the first electrode terminal 22 and the first pole tab 232 are both located on the same side of the main body 231 in the thickness direction X of the wall portion. On the one hand, the difficulty of assembling the first pole tab 232 and the first electrode terminal 22 can be reduced, which is beneficial to improving the production efficiency of the battery cell 20. On the other hand, there is no need to excessively extend the first pole tab 232, which is beneficial to reducing the redundancy of the first pole tab 232, thereby reducing the risk of overlap between the first pole tab 232 and other components, and reducing the risk of the first pole tab 232 being inserted upside down into the main body 231 of the electrode assembly 23.

[0210] According to some embodiments of the present application, as shown in Figures 7 and 9 , the first electrode tab 232 and the collection electrode tab 233 are spaced apart and disposed at the same end of the main body 231. In other words, the first electrode tab 232 and the collection electrode tab 233 are located at the same end of the main body 231, and the first electrode tab 232 and the collection electrode tab 233 are spaced apart from each other.

[0211] Illustratively, the first electrode tab 232 and the collecting electrode tab 233 are both connected to an end of the main body 231 facing the wall 211 in the wall thickness direction X, and the first electrode tab 232 and the collecting electrode tab 233 are spaced apart along the first direction Y. Of course, in other embodiments, the first electrode tab 232 and the collecting electrode tab 233 may also be disposed on an end of the main body 231 away from the wall 211 in the wall thickness direction X.

[0212] In this embodiment, by arranging the first pole tab 232 and the collecting pole tab 233 to be located at the same end of the main body 231, and the first pole tab 232 and the collecting pole tab 233 are arranged at intervals, it is convenient to lead out the first pole tab 232 and the collecting pole tab 233 with the same polarity at the same end of the main body 231, which is beneficial to reducing the manufacturing difficulty of the electrode assembly 23, thereby improving the production efficiency of the battery cell 20, and reducing the risk of overlap between the first pole tab 232 and the collecting pole tab 233.

[0213] In some embodiments, as shown in FIG. 9 and FIG. 10 , the minimum distance between the first electrode tab 232 and the collection electrode tab 233 is D1 , satisfying D1 ≥ 5 mm.

[0214] The first tabs 232 and the collecting tabs 233 are spaced apart along the first direction Y. Correspondingly, the minimum distance D1 between the first tabs 232 and the collecting tabs 233 is the minimum distance between the first tabs 232 and the collecting tabs 233 in the first direction Y.

[0215] Illustratively, the minimum distance D1 between the first tab 232 and the collection tab 233 may be 5 mm, 5.2 mm, 5.5 mm, 5.6 mm, 5.8 mm, 6 mm, 6.2 mm, 6.5 mm, 6.8 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm, or 11 mm.

[0216] In this embodiment, by setting the distance between the first pole tab 232 and the collecting pole tab 233 to be greater than or equal to 5 mm, the spacing between the first pole tab 232 and the collecting pole tab 233 is further expanded, thereby further reducing the overlap risk between the first pole tab 232 and the collecting pole tab 233, and further reducing the overlap phenomenon between the collecting pole tab 233 and the first pole tab 232 after melting, thereby reducing the overlap risk between the wall portion 211 and the first pole tab 232.

[0217] According to some embodiments of the present application, as shown in Figures 4, 7, and 9, the battery cell 20 further includes a second electrode terminal 25, which is insulated and mounted on the housing 21. The electrode assembly 23 further includes a second electrode tab 234, which is electrically connected to the second electrode terminal 25. The polarity of the second electrode tab 234 is opposite to that of the first electrode tab 232. The second electrode tab 234 and the first electrode tab 232 are disposed at the same end of the main body 231, and the second electrode tab 234 and the first electrode tab 232 are spaced apart along the first direction Y. Along the first direction Y, the collection tab 233 is located between the first electrode tab 232 and the second electrode tab 234.

[0218] Exemplarily, the second electrode terminal 25 is insulated and mounted on the wall portion 211, and correspondingly, the first pole tab 232 and the second pole tab 234 are both arranged at one end of the main body 231 facing the wall portion 211 in the thickness direction X of the wall portion, and the collecting pole tab 233 is located between the first pole tab 232 and the second pole tab 234 in the first direction Y.

[0219] In this embodiment, the second pole tab 234 and the first pole tab 232 of the electrode assembly 23 are both arranged at the same end of the main body 231, so that the first pole tab 232 and the second pole tab 234 are easily led out at the same end of the main body 231, which is beneficial to reducing the manufacturing difficulty of the electrode assembly 23 and improving the production efficiency of the battery cell 20. Specifically, by arranging the first pole tab 232 and the second pole tab 234 at intervals along the first direction Y and arranging the collecting pole tab 233 between the first pole tab 232 and the second pole tab 234 in the first direction Y, the risk of short circuit between the first pole tab 232 and the second pole tab 234 can be reduced, and the risk of short circuit between the collecting pole tab 233 and the second pole tab 234 can be reduced.

[0220] In some embodiments, as shown in FIG10 , along the first direction Y, the distance between the collecting tab 233 and the first tab 232 is smaller than the distance between the collecting tab 233 and the second tab 234. In other words, the collecting tab 233 is located in the first direction Y at a position between the first tab 232 and the second tab 234 and biased toward the first tab 232.

[0221] In this embodiment, by setting the distance between the collecting pole tab 233 and the second pole tab 234 in the first direction Y to be greater than the distance between the collecting pole tab 233 and the first pole tab 232 in the first direction Y, the collecting pole tab 233 is closer to the first pole tab 232 in the first direction Y, so as to further reduce the overlap between the collecting pole tab 233 and the second pole tab 234 with different polarities, thereby effectively reducing the risk of short circuit between the collecting pole tab 233 and the second pole tab 234 during use of the battery cell 20.

[0222] In some embodiments, please continue to refer to FIG. 10 , along the first direction Y, the minimum distance between the second electrode tab 234 and the collection electrode tab 233 is D2 , satisfying D2 ≥ 5 mm.

[0223] Exemplarily, the minimum distance D2 between the second tab 234 and the collection tab 233 may be 5 mm, 5.2 mm, 5.5 mm, 5.6 mm, 5.8 mm, 6 mm, 6.2 mm, 6.5 mm, 6.8 mm, 7 mm, 7.5 mm, 8 mm, 8.5 mm, 9 mm, 9.5 mm, 10 mm or 11 mm, etc.

[0224] In this embodiment, by setting the distance between the second pole tab 234 and the collecting pole tab 233 to be greater than or equal to 5 mm, the spacing between the second pole tab 234 and the collecting pole tab 233 is further expanded, thereby further reducing the short circuit phenomenon between the second pole tab 234 and the collecting pole tab 233, thereby reducing the risk of short circuit between the second pole tab 234 and the collecting pole tab 233 with different polarities.

[0225] According to some embodiments of the present application, as shown in Figures 3 and 4, the second electrode terminal 25 is insulated and installed on the wall portion 211, along the thickness direction X of the wall portion, and the second electrode tab 234 is arranged at one end of the main body 231 facing the wall portion 211, and the thickness direction X of the wall portion is perpendicular to the first direction Y.

[0226] Among them, along the thickness direction X of the wall portion, the second electrode tab 234 is arranged at the end of the main body 231 facing the wall portion 211. Correspondingly, the first electrode tab 232 and the collection electrode tab 233 are both arranged at the end of the main body 231 facing the wall portion 211 in the thickness direction X of the wall portion, and the first electrode terminal 22 is insulated and installed on the wall portion 211.

[0227] In this embodiment, the second electrode terminal 25 is insulated and installed on the wall portion 211, and the second pole tab 234 is arranged at one end of the main body 231 facing the wall portion 211 in the thickness direction X of the wall portion, so that the second electrode terminal 25 and the second pole tab 234 are both located on the side of the main body 231 facing the wall portion 211 in the thickness direction X of the wall portion. On the one hand, the difficulty of assembling the second pole tab 234 and the second electrode terminal 25 can be reduced, which is beneficial to improving the production efficiency of the battery cell 20. On the other hand, there is no need to excessively extend the second pole tab 234, which is beneficial to reducing the redundancy of the second pole tab 234, thereby reducing the risk of overlap between the second pole tab 234 and other components, and reducing the risk of the second pole tab 234 being inserted upside down into the main body 231 of the electrode assembly 23.

[0228] According to some embodiments of the present application, as shown in FIG. 5 and FIG. 6 , the collecting tab 233 is welded to the wall portion 211 .

[0229] In the embodiment where the collecting tab 233 includes a first connecting segment 2333, the collecting tab 233 is welded to the wall portion 211 by the first connecting segment 2333, forming a weld mark 29. It should be noted that in the embodiment where the first connecting segment 2333 of the collecting tab 233 includes a first connecting portion 23331 and a second connecting portion 23332, the weld mark 29 is formed on the first connecting portion 23331. In other words, the first connecting portion 23331 of the first connecting segment 2333 is welded to the wall portion 211, forming the weld mark 29.

[0230] For example, the collecting tab 233 and the wall portion 211 may be welded by laser welding or ultrasonic welding.

[0231] In this embodiment, a welding connection structure is used to connect the collecting tab 233 and the wall portion 211, which is beneficial to improving the connection reliability and connection stability between the collecting tab 233 and the wall portion 211, thereby reducing the phenomenon of connection failure between the collecting tab 233 and the wall portion 211 caused by accidental separation of the collecting tab 233 and the wall portion 211 during the use of the battery cell 20.

[0232] In some embodiments, the welding area between the collecting tab 233 and the wall portion 211 is S2, which satisfies the following conditions: 30 mm 2 ≤S2≤100mm 2 .

[0233] The welding area S2 between the collecting tab 233 and the wall portion 211 refers to the cross-sectional area S2 of the weld mark 29 formed by the weld connection between the collecting tab 233 and the wall portion 211 at the interface between the collecting tab 233 and the wall portion 211. That is, in the embodiment where the collecting tab 233 includes a first connecting segment 2333, and the first connecting segment 2333 includes a first connecting portion 23331 and a second connecting portion 23332, the welding area S2 between the collecting tab 233 and the wall portion 211 refers to the cross-sectional area S2 of the weld mark 29 formed by the weld connection between the first connecting portion 23331 and the wall portion 211 at the interface between the first connecting portion 23331 and the wall portion 211.

[0234] In this embodiment, the welding area between the collecting tab 233 and the wall portion 211 is set to 30 mm. 2 Up to 100mm 2 On the one hand, the welding area between the collecting tab 233 and the wall 211 is set to be greater than or equal to 30mm 2 , in order to improve the welding effect between the collecting tab 233 and the wall portion 211, thereby improving the connection reliability and connection stability between the collecting tab 233 and the wall portion 211. On the other hand, the welding area between the collecting tab 233 and the wall portion 211 is set to be less than or equal to 100mm2 , in order to reduce the welding difficulty between the collecting tab 233 and the wall portion 211, and to reduce the welding power required for welding the collecting tab 233 and the wall portion 211 to each other, thereby effectively reducing the assembly difficulty between the collecting tab 233 and the wall portion 211, which is beneficial to improving the production efficiency of the battery cell 20 and reducing the production cost of the battery cell 20. Therefore, the welding area between the collecting tab 233 and the wall portion 211 is set to 30mm 2 Up to 100mm 2 , while taking into account the welding quality between the collecting tab 233 and the wall portion 211 , it can also effectively reduce the difficulty of welding and assembling between the collecting tab 233 and the wall portion 211 .

[0235] According to some embodiments of the present application, the first tab 232 includes M tab sheets stacked together, and the collection tab 233 includes N tab sheets stacked together, satisfying M>N.

[0236] Among them, the first pole tab 232 includes M pole tab sheets stacked together, that is, the first pole tab 232 is formed by stacking multiple current collector sheets in the positive electrode sheet or the negative electrode sheet that are not coated with the active material layer. Similarly, the collection pole tab 233 includes N pole tab sheets stacked together, that is, the collection pole tab 233 is formed by stacking multiple current collector sheets in the positive electrode sheet or the negative electrode sheet that are not coated with the active material layer. M>N, that is, the number of current collector sheets stacked by the collection pole tab 233 is less than the number of current collector sheets stacked by the first pole tab 232.

[0237] In this embodiment, by making the number of stacked tabs of the collecting tab 233 smaller than the number of stacked tabs of the first tab 232, since the overcurrent requirement of the collecting tab 233 is smaller than that of the first tab 232, the collecting tab 233 can be electrically connected to the wall 211 of the shell 21 and can be used for data collection by the information collection equipment while reducing the manufacturing difficulty of the collecting tab 233, thereby improving the production efficiency of the battery cell 20.

[0238] According to some embodiments of the present application, as shown in Figures 4 and 7 , the first tab 232 is the positive tab of the electrode assembly 23. In other words, the first tab 232 is a component formed by stacking and connecting the areas of the positive electrode sheet that are not coated with the positive electrode active material layer. The first tab 232 and the collection tab 233 are both used to output or input the positive electrode of the electrode assembly 23.

[0239] In this embodiment, by setting the first pole ear 232 as the positive pole ear of the electrode assembly 23, the first pole ear 232 is used to output or input the positive electrode of the electrode assembly 23, and correspondingly, the collection pole ear 233 is used to output the positive electrode of the electrode assembly 23, so that the wall 211 is a positively charged structure when the information collection device performs data collection. The battery cell 20 with this structure can effectively alleviate the phenomenon of electrical corrosion of the outer shell 21 of the battery cell 20, thereby helping to improve the service life of the battery cell 20 and helping to reduce the risk of leakage of the battery cell 20 during use.

[0240] According to some embodiments of the present application, as shown in Figures 3 and 4, the battery cell 20 may further include a second electrode terminal 25, which is insulated and mounted on the housing 21. The electrode assembly 23 also includes a second electrode tab 234, which is disposed on the main body 231 and electrically connected to the second electrode terminal 25. The polarity of the second electrode tab 234 is opposite to that of the first electrode tab 232.

[0241] In this embodiment, the battery cell 20 is also provided with a second electrode terminal 25. Correspondingly, the electrode assembly 23 also includes a second pole ear 234. The polarity of the second pole ear 234 is opposite to that of the first pole ear 232, and the second pole ear 234 is electrically connected to the second electrode terminal 25, so that the first electrode terminal 22 and the second electrode terminal 25 cooperate to input or output the positive and negative poles of the battery cell 20. In this regard, by insulating the second electrode terminal 25 and installing it on the outer shell 21, it is helpful to reduce the risk of short circuit between the second electrode terminal 25 and the collecting pole ear 233.

[0242] According to some embodiments of the present application, as shown in Figures 3 and 4, the housing 21 may include a shell 212 and an end cap 213. The shell 212 has an interior formed with an accommodating cavity having an opening 2121 for accommodating the electrode assembly 23. The end cap 213 closes the opening 2121 and is a wall portion 211.

[0243] The end cap 213 is the wall portion 211, that is, the collecting tab 233 is electrically connected to the end cap 213 of the housing 21. In the embodiment where the first electrode terminal 22 and the second electrode terminal 25 are insulated and mounted on the wall portion 211, both the first electrode terminal 22 and the second electrode terminal 25 are insulated and mounted on the end cap 213 of the housing 21.

[0244] In this embodiment, by setting the wall portion 211 of the shell 21 as the end cover 213 of the shell 21 for closing the opening 2121 of the shell 212, the battery cell 20 adopting this structure facilitates the connection of the collecting tab 233 with the wall portion 211 of the shell 21, which is beneficial to reducing the difficulty of assembling the battery cell 20 and improving the production efficiency of the battery cell 20.

[0245] It should be noted that the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 may also have other structures. For example, the outer shell 21 may include a shell 212 and an end cap 213. The shell 212 includes an integrally formed sidewall and wall portion 211. The sidewall is arranged around the wall portion 211. Along the thickness direction X of the wall portion, one end of the sidewall is connected to the wall portion 211, and the other end encloses an opening 2121. The sidewall and wall portion 211 jointly define a cavity for accommodating the electrode assembly 23. The end cap 213 closes the opening 2121. In other words, the collecting tab 233 and the shell 212 are connected to the bottom wall opposite the end cap 213 in the thickness direction X of the wall portion.

[0246] In this embodiment, by setting the wall portion 211 of the outer shell 21 as a wall arranged opposite to the end cover 213 in the thickness direction X of the wall portion of the shell 212, the battery cell 20 adopting this structure can make the wall portion 211 used for connecting with the collection tab 233 away from the end cover 213, so that there is no direct connection relationship between the wall portion 211 and the end cover 213, thereby alleviating the influence of the stress generated by the mutual assembly between the end cover 213 and the shell 212 on the collection tab 233, which is beneficial to improving the service life of the collection tab 233, and can alleviate the phenomenon that the force generated by other components pulling or twisting the wall portion 211 acts on the end cover 213, thereby reducing the risk of connection failure between the end cover 213 and the shell 212, and further helping to further reduce the risk of leakage of the battery cell 20 during use.

[0247] According to some embodiments of the present application, the present application further provides a battery 100 , which includes the battery cell 20 of any of the above solutions.

[0248] As shown in FIG. 2 , the battery 100 may further include a box body 10 , in which the battery cells 20 are accommodated.

[0249] In some embodiments, the box body 10 may include a first box body 11 and a second box body 12 . The first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cells 20 .

[0250] 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, and 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 jointly define an 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.

[0251] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder or a rectangular parallelepiped, etc. For example, in FIG2 , the box body 10 is a rectangular parallelepiped structure.

[0252] Optionally, the number of battery cells 20 disposed within the housing 10 may be one or more. For example, in FIG2 , the housing 10 of the battery 100 includes multiple battery cells 20, which may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a configuration in which multiple battery cells 20 are connected in both series and parallel. Multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure formed by the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 may comprise multiple battery cells 20 that are first connected in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single structure, which is then housed within the housing 10.

[0253] The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component that connects the plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0254] It should be noted that in some embodiments, the battery 100 may not be provided with a housing 10. The battery 100 includes multiple battery cells 20, and the battery 100 composed of multiple battery cells 20 can be directly assembled on an electrical device to provide electrical energy to the electrical device through the multiple battery cells 20. In other words, the housing 10 can serve as part of the electrical device. Taking the vehicle 1000 as an example, the housing 10 can serve as part of the chassis structure of the vehicle 1000. For example, a portion of the housing 10 can form at least a portion of the floor of the vehicle 1000, or a portion of the housing 10 can form at least a portion of the crossbeam and longitudinal beam of the vehicle 1000.

[0255] In some embodiments, as shown in FIG2 , the battery 100 may further include a battery management system (not shown). The battery management system is electrically connected to the wall 211 of the housing 21 and is configured to issue an early warning when the collecting tab 233 is fused.

[0256] The battery management system is used to manage and monitor the usage status of the battery 100. The specific structure of the battery management system can be found in related technologies and will not be described in detail here.

[0257] The battery management system is configured to issue an early warning when the collecting tab 233 is blown. That is, when the collecting tab 233 is blown due to a short circuit in the battery cell 20, causing the electrode assembly 23 to be electrically disconnected from the wall 211 of the outer shell 21, the battery management system can receive a circuit breaker signal and issue an early warning message, such as an alarm or a warning.

[0258] In this embodiment, the battery 100 is also provided with a battery management system, which is electrically connected to the wall portion 211, and the battery management system can issue an early warning after a short circuit occurs in the battery cell 20 and causes the collection tab 233 to fuse, so as to provide an early warning reminder to the operator or user, thereby reducing the further damage or impact caused by the short circuit of the battery cell 20 to the operator or user, which is beneficial to improving the reliability of the battery 100.

[0259] According to some embodiments of the present application, the present application further provides an electrical device, which includes the battery cell 20 of any of the above solutions, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0260] The electrical device may be any of the aforementioned devices or systems using the battery cell 20 .

[0261] According to some embodiments of the present application, as shown in Figures 3 to 10 , a battery cell 20 is provided. The battery cell 20 includes a housing 21, an electrode assembly 23, a first electrode terminal 22, and a second electrode terminal 25. The housing 21 has a wall portion 211. The housing 21 includes a shell 212 and an end cap 213. The interior of the shell 212 forms a receiving cavity with an opening 2121. The end cap 213 closes the opening 2121. The end cap 213 serves as the wall portion 211. The electrode assembly 23 is received within the receiving cavity of the shell 212. The electrode assembly 23 includes a main body 231, a first electrode tab 232, a collecting electrode tab 233, and a second electrode tab 234. The first electrode tab 232 and the collecting electrode tab 233 have the same polarity. The first electrode tab 232 is the positive electrode tab of the electrode assembly 23, and the second electrode tab 234 is the negative electrode tab of the electrode assembly 23. The first pole tab 232, the collecting pole tab 233, and the second pole tab 234 are all disposed at one end of the main body 231 facing the wall 211 in the wall thickness direction X. The first pole tab 232 and the second pole tab 234 are spaced apart along the first direction Y. The collecting pole tab 233 is located between the first pole tab 232 and the second pole tab 234 in the first direction Y. The first direction Y is perpendicular to the wall thickness direction X. Along the first direction Y, the distance between the collecting pole tab 233 and the first pole tab 232 is smaller than the distance between the collecting pole tab 233 and the second pole tab 234. The minimum distance between the first pole tab 232 and the collecting pole tab 233 is D1, satisfying D1 ≥ 5 mm. The minimum distance between the second pole tab 234 and the collecting pole tab 233 is D2, satisfying D2 ≥ 5 mm. The first electrode terminal 22 and the second electrode terminal 25 are both insulated and installed on the wall portion 211. The first electrode terminal 22 is electrically connected to the first electrode tab 232, and the second electrode terminal 25 is electrically connected to the second electrode tab 234. The collecting tab 233 is connected to the wall portion 211, and the minimum flow area of ​​the collecting tab 233 is smaller than the minimum flow area of ​​the first electrode tab 232.

[0262] Among them, the collecting tab 233 includes a first connecting section 2333, a weak section 2331 and a second connecting section 2334 connected in sequence. The first connecting section 2333 is connected to the wall portion 211, and the second connecting section 2334 is connected to the main body 231. The minimum flow area of ​​the first connecting section 2333 and the second connecting section 2334 is greater than the minimum flow area of ​​the weak section 2331. The minimum flow area of ​​the weak section 2331 is the minimum flow area S1 of the collecting tab 233, which meets 2mm. 2 ≤S1≤20mm 2 . Along the extension direction of the collecting tab 233, the length of the weak section 2331 is L, satisfying 0.3mm≤L≤5mm. The first connecting section 2333 includes a first connecting portion 23331 and a second connecting portion 23332. The first connecting portion 23331 is welded to the wall portion 211. The first connecting portion 23331 has a first surface 23331a facing the wall portion 211 and a second surface 23331b facing away from the wall portion 211. The first surface 23331a and the second surface 23331b are both rough surfaces. The second connecting portion 23332 connects the first connecting portion 23331 and the weak section 2331, and the second connecting portion 23332 does not contact the wall portion 211. Along the extension direction of the collecting tab 233, the length of the second connecting portion 23332 is greater than the length of the second connecting section 2334.

[0263] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0264] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, comprising: a housing having a wall portion; a first electrode terminal, insulated and mounted on the housing; as well as an electrode assembly housed in the housing, the electrode assembly comprising a main body and a first tab, the first tab being disposed on the main body and electrically connected to the first electrode terminal; In which, the electrode assembly also includes a collecting tab, which is arranged on the main body, has the same polarity as the first tab, is electrically connected to the wall, and has a minimum flow area smaller than the minimum flow area of the first tab.

2. The battery cell according to claim 1, wherein: The minimum flow area of the collecting tab is S1, which satisfies 2mm 2 ≤S1≤20mm 2 .

3. The battery cell according to claim 1 or 2, wherein: The portion of the collecting tab forms a weak section, and the minimum flow area of the weak section is the minimum flow area S1 of the collecting tab.

4. The battery cell according to claim 3, wherein: Along the extension direction of the collecting tab, the length of the weak section is L, which satisfies 0.3 mm ≤ L ≤ 5 mm.

5. The battery cell according to claim 3 or 4, wherein: The collecting tab further includes a first connecting section, the minimum flow area of the first connecting section is larger than the minimum flow area of the weak section, and the first connecting section connects the wall portion and the weak section. The battery cell according to claim 5 , wherein: The first connecting section includes a first connecting portion and a second connecting portion, the first connecting portion is connected to the wall portion, the second connecting portion connects the first connecting portion and the weak section, and the second connecting portion does not contact the wall portion.

7. The battery cell according to claim 6, wherein: The first connecting portion is welded to the wall portion, and along the thickness direction of the wall portion, the first connecting portion has a first surface facing the wall portion and a second surface facing away from the wall portion, and the first surface is connected to the wall portion; Wherein, the first surface is a rough surface; and / or The second surface is a rough surface.

8. The battery cell according to any one of claims 3 to 7, wherein: The collecting tab further includes a second connecting section, the minimum flow area of the second connecting section is larger than the minimum flow area of the weak section, and the second connecting section connects the weak section and the main body.

9. The battery cell according to claim 8, wherein: The collecting tab further includes a first connecting section, the first connecting section including a first connecting portion and a second connecting portion, the first connecting portion being connected to the wall portion, the second connecting portion connecting the first connecting portion and the weak section, and the second connecting portion not being in contact with the wall portion; Wherein, along the extension direction of the collecting tab, the length of the second connecting portion is greater than the length of the second connecting section.

10. The battery cell according to any one of claims 1 to 9, wherein: Along the thickness direction of the wall portion, the collecting tab is provided at one end of the main body portion facing the wall portion.

11. The battery cell according to any one of claims 1 to 10, wherein: The first electrode terminal is insulated and mounted on the wall portion. Along the thickness direction of the wall portion, the first electrode tab is provided at one end of the main body portion facing the wall portion.

12. The battery cell according to any one of claims 1 to 11, wherein: The first electrode tab and the collecting electrode tab are spaced apart and arranged at the same end of the main body.

13. The battery cell according to claim 12, wherein: The minimum distance between the first electrode tab and the collection electrode tab is D1, which satisfies D1≥5mm.

14. The battery cell according to claim 12 or 13, wherein: The battery cell further includes a second electrode terminal, the second electrode terminal being insulated and mounted on the housing; The electrode assembly further includes a second electrode tab, the second electrode tab being electrically connected to the second electrode terminal, the polarity of the second electrode tab being opposite to that of the first electrode tab, the second electrode tab being disposed at the same end of the main body as the first electrode tab, and the second electrode tab being spaced apart from the first electrode tab along a first direction; Wherein, along the first direction, the collecting tab is located between the first tab and the second tab.

15. The battery cell according to claim 14, wherein: Along the first direction, the distance between the collecting tab and the first tab is smaller than the distance between the collecting tab and the second tab.

16. The battery cell according to claim 14 or 15, wherein: Along the first direction, the minimum distance between the second electrode tab and the collection electrode tab is D2, satisfying D2 ≥ 5 mm.

17. The battery cell according to any one of claims 14 to 16, wherein: The second electrode terminal is insulated and mounted on the wall portion. The second electrode tab is provided at one end of the main body portion facing the wall portion along the thickness direction of the wall portion. The thickness direction of the wall portion is perpendicular to the first direction.

18. The battery cell according to any one of claims 1 to 17, wherein: The collecting tab is connected to the wall portion by welding.

19. The battery cell according to claim 18, wherein: The welding area between the collecting tab and the wall is S2, which satisfies 30mm 2 ≤S2≤100mm 2 .

20. The battery cell according to any one of claims 1 to 19, wherein: The first electrode tab includes M electrode tab sheets arranged in a stacked manner, and the collection electrode tab includes N electrode tab sheets arranged in a stacked manner, satisfying M>N.

21. The battery cell according to any one of claims 1 to 20, wherein: The first electrode tab is the positive electrode tab of the electrode assembly.

22. The battery cell according to any one of claims 1 to 21, wherein: The battery cell further includes a second electrode terminal, the second electrode terminal being insulated and mounted on the housing; The electrode assembly further includes a second tab, which is provided on the main body and electrically connected to the second electrode terminal. The second electrode tab is connected to the first electrode tab, and the polarity of the second electrode tab is opposite to that of the first electrode tab.

23. The battery cell according to any one of claims 1 to 22, wherein: The housing comprises: A housing having an opening formed therein, wherein the housing is used to accommodate the electrode assembly; an end cap for closing the opening; Wherein, the end cover is the wall portion.

24. The battery cell according to any one of claims 1 to 22, wherein: The housing comprises: The housing includes an integrally formed sidewall and the wall portion, the sidewall being disposed around the wall portion, one end of the sidewall being connected to the wall portion along the thickness direction of the wall portion, and the other end of the sidewall being enclosed to form an opening, the sidewall and the wall portion jointly defining a housing cavity for accommodating the electrode assembly; An end cap closes the opening.

25. A battery comprising the battery cell according to any one of claims 1 to 24.

26. The battery according to claim 25, wherein The battery further comprises: A battery management system is electrically connected to the wall portion, and the battery management system is configured to issue an early warning when the collection tab is blown.

27. An electrical device comprising the battery cell according to any one of claims 1 to 24, wherein the battery cell is used to provide electrical energy.

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