Battery monomer, battery and electric device

Abstract

The utility model discloses a battery monomer, a battery and an electric device, and belongs to the technical field of batteries. The battery cell comprises a shell assembly, an electrode assembly and a current collecting component. The shell assembly comprises an electrode leading-out part used for inputting or outputting electric energy. The electrode assembly is contained in the shell assembly and comprises a main body and a tab, the tab is arranged on the main body, and the tab and the electrode leading-out part are made of different materials. The current collecting component comprises an additional part made of the same material as the electrode leading-out part and a body part made of the same material as the tab, the additional part is connected with the body part, the additional part is welded with the electrode leading-out part, and the body part is welded with the tab. The additional part and the electrode lead-out part are arranged to be mutually welded by the same material, so that the phenomena of different melting points, different thermal expansion coefficients and the like caused by welding of the current collecting component and the electrode lead-out part due to different materials are relieved, the phenomenon of welding cracks of the current collecting component and the electrode lead-out part is reduced, and the liquid leakage risk of the battery monomer is favorably reduced.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 2023104839607, filed on April 28, 2023, entitled “Battery Cell, Battery and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] 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

[0004] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, 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. Batteries, as core components of new energy vehicles, have high requirements for reliability in use. Among them, battery cells usually include a shell and an electrode assembly and electrolyte contained in the shell. However, existing battery cells often leak electrolyte during use, resulting in poor reliability of battery cells. Utility Model Content

[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 assembly, an electrode assembly and a current collecting component; the shell assembly comprises an electrode lead-out portion for inputting or outputting electrical energy; the electrode assembly is accommodated in the shell assembly, the electrode assembly comprises a main body and a pole ear, the pole ear is arranged on the main body, and the pole ear and the electrode lead-out portion are made of different materials; the current collecting component is arranged in the shell assembly, the current collecting component comprises a main body portion made of the same material as the pole ear and an additional portion made of the same material as the electrode lead-out portion, the main body portion is connected to the additional portion, the main body portion is welded to the pole ear, and the additional portion is welded to the electrode lead-out portion.

[0007] In the above technical solution, the current collecting component is provided with a main body part and an additional part which are connected to each other, the main body part is welded to the pole lug, and the additional part is welded to the electrode lead-out part of the shell assembly to realize the electrical connection between the electrode assembly and the electrode lead-out part, so as to realize the input or output of electric energy of the battery cell, wherein, by setting the material of the main body part to be the same as the material of the pole lug, and setting the material of the additional part to be the same as the material of the electrode lead-out part, the battery cell of this structure is convenient for welding the current collecting component to the electrode lead-out part and the current collecting component to the pole lug, which is beneficial to reduce the assembly difficulty between the current collecting component and the electrode lead-out part and between the current collecting component and the pole lug of the electrode assembly, so as to improve the assembly efficiency of the battery cell, and on the other hand, it can realize the mutual welding between the current collecting component and the electrode lead-out part with the same material, so as to alleviate the phenomenon of different melting points and different thermal expansion coefficients caused by welding the current collecting component and the electrode lead-out part due to different materials, so as to reduce the phenomenon of welding cracks between the current collecting component and the electrode lead-out part, which is beneficial to reduce the leakage risk of the battery cell, so as to improve the reliability of the battery cell.

[0008] In some embodiments, along a first direction, at least a portion of the current collecting member is disposed between the electrode assembly and the electrode lead-out portion; wherein, along the first direction, the additional portion is connected to a side of the main body portion facing away from the electrode assembly.

[0009] In the above technical solution, by disposing at least a portion of the current collecting component between the electrode assembly and the electrode lead-out portion, and the additional portion is disposed on the side of the main body portion away from the electrode assembly in the first direction, the additional portion and the main body portion of the current collecting component are structures arranged along the first direction, and the additional portion is disposed facing the electrode lead-out portion, thereby facilitating mutual welding of the additional portion of the current collecting component and the electrode lead-out portion of the shell assembly, and facilitating mutual welding of the main body portion of the current collecting component and the electrode tab of the electrode assembly, which is beneficial to reducing the difficulty of assembling the electrode lead-out portion and the electrode tab to be connected to the current collecting component, so as to improve the assembly efficiency of the battery cell.

[0010] In some embodiments, along the first direction, the main body portion has a first surface facing the electrode lead-out portion, the first surface is provided with a receiving groove, and at least a portion of the additional portion is received in the receiving groove.

[0011] In the above technical solution, by providing a receiving groove on the first surface of the main body facing the electrode lead-out portion, and at least a portion of the additional portion is received in the receiving groove of the main body, the space occupied by the current collecting component in the first direction can be reduced, and the weight of the current collecting component can be reduced, which is beneficial to optimize the weight of the battery cell and the size in the first direction to improve the energy density of the battery cell.

[0012] In some embodiments, along the first direction, the additional portion protrudes from the first surface, and a portion of the additional portion protruding from the first surface is welded to the electrode lead portion.

[0013] In the above technical solution, by setting the additional part as the first surface of the main body part protruding in the first direction, that is, the additional part extends the accommodating groove in the first direction, so that the part of the additional part extending out of the accommodating groove can abut against the electrode lead-out part, thereby reducing the phenomenon of a gap between the additional part and the electrode lead-out part due to the interference of the main body part, which is beneficial to improving the contact effect between the additional part and the electrode lead-out part, thereby alleviating the risk of cold welding or poor welding between the additional part and the electrode lead-out part, and further effectively improving the welding effect between the additional part and the electrode lead-out part.

[0014] In some embodiments, along the first direction, the additional portion has a second surface facing the electrode lead-out portion, and the second surface is flush with the first surface.

[0015] In the above technical solution, by arranging the second surface of the additional part facing the electrode lead-out part in the first direction and the first surface of the main body part facing the electrode lead-out part in the first direction to be flush, the thickness of the additional part in the first direction is made to be the same as the depth of the accommodating groove in the first direction, thereby reducing the phenomenon of a gap between the additional part and the electrode lead-out part due to the interference of the main body part and further optimizing the occupied space of the current collecting member in the electrode lead-out part and the electrode assembly, which is beneficial to improving the internal space utilization of the battery cell, and further improving the energy density of the battery cell.

[0016] In some embodiments, the additional portion is an annular structure.

[0017] In the above technical solution, by setting the additional part as a ring structure, it is beneficial to increase the welding area between the additional part and the electrode lead-out part, so as to improve the connection stability between the additional part and the electrode lead-out part, and the additional part with a ring structure can improve the overcurrent balance between the current collecting component and the electrode lead-out part, which is beneficial to reduce the phenomenon of large local overcurrent between the current collecting component and the electrode lead-out part.

[0018] In some embodiments, the accommodating groove is an annular groove extending along the extension direction of the additional portion.

[0019] In the above technical solution, by setting the receiving groove in an annular groove with the same extension direction as the additional part, on the one hand, it is convenient to accommodate the additional part in the receiving groove, and can play a certain limiting and positioning role on the additional part, which is beneficial to reduce the difficulty of assembly between the additional part and the main body. On the other hand, it is only necessary to set an annular receiving groove on the first surface to match the shape of the additional part, which is beneficial to reduce the processing difficulty of the receiving groove and reduce the processing range of the receiving groove.

[0020] In some embodiments, the current collecting component includes a plurality of the additional parts, each of which is connected to the main body, and along the first direction, projections of the plurality of the additional parts in a plane perpendicular to the first direction do not overlap with each other.

[0021] In the above technical solution, the current collecting component is provided with a plurality of additional parts, all of which are connected to the side of the main body away from the electrode assembly, and the projections of the plurality of additional parts in the first direction do not overlap, so that after the plurality of additional parts are welded to the electrode lead-out part, the current flow efficiency between the current collecting component and the electrode lead-out part can be improved.

[0022] In some embodiments, the main body portion is connected to the additional portion by welding.

[0023] In the above technical solution, the main body and the additional part are connected by welding, which can effectively improve the connection strength and connection stability between the additional part and the main body, so as to reduce the phenomenon of separation between the additional part and the main body during use, which is beneficial to improve the overcurrent stability between the additional part and the main body, thereby effectively improving the use stability of the battery cell.

[0024] In some embodiments, along a first direction, the current collecting member is arranged between the electrode assembly and the electrode lead-out portion; wherein, along the first direction, the main body portion has a first surface facing the electrode lead-out portion, and along a second direction, the additional portion has a first side surface, the first side surface is welded to the first surface, and the second direction is perpendicular to the first direction.

[0025] In the above technical scheme, the first surface of the main body in the first direction and the first side surface of the additional part in the second direction are welded to each other, so that the main body and the additional part are in a fillet welding connection relationship to achieve a welding connection between the main body and the additional part. The current collecting component with such a structure can, on the one hand, achieve a greater penetration depth at a lower welding power, which is beneficial to improving the welding effect between the additional part and the main body, thereby effectively improving the connection stability between the additional part and the main body; on the other hand, it can achieve that the weld mark formed by the welding between the additional part and the main body is located on one side of the additional part in the second direction, thereby reducing the interference effect of the weld mark formed by the mutual welding of the additional part and the main body on the mutual abutment and welding connection between the additional part and the electrode lead-out part in the first direction, which is beneficial to improving the contact effect between the additional part and the electrode lead-out part, so as to alleviate the risk of false welding or poor welding between the additional part and the electrode lead-out part, thereby effectively improving the welding quality between the additional part and the electrode lead-out part.

[0026] In some embodiments, along the second direction, the additional portion has two first side surfaces that are oppositely disposed, and both of the two first side surfaces are welded to the first surface.

[0027] In the above technical solution, by welding the two first side surfaces of the additional part opposite to each other in the second direction to the first surface, it is beneficial to improve the connection strength and connection stability between the additional part and the main body, and can improve the flow efficiency between the additional part and the main body.

[0028] In some embodiments, the additional portion is an annular structure, and the two first side surfaces are respectively an inner circumferential surface and an outer circumferential surface of the additional portion.

[0029] In the above technical solution, by setting the additional part as a ring structure, and welding the inner circumference and the outer circumference of the additional part to the first surface of the main body, it is beneficial to increase the welding area between the additional part and the main body, so as to further improve the connection stability between the additional part and the main body, and can improve the flow balance between the additional part and the main body, which is beneficial to reduce the phenomenon of large local flow between the additional part and the main body.

[0030] In some embodiments, the two first side surfaces are both connected to the first surface by welding to form two first welding portions; wherein the projections of the two first welding portions in a plane perpendicular to the first direction do not overlap.

[0031] In the above technical solution, the projections of two first welding parts formed by welding the two first side faces of the additional part to the first surface of the main body part in the first direction are set to be non-overlapping, so that the two first welding parts are staggered in the first direction, thereby reducing the phenomenon of molten pool penetration between the two first welding parts, which is beneficial to improving the welding quality between the additional part and the main body.

[0032] In some embodiments, the first surface is provided with a receiving groove for receiving the additional part, and along the first direction, the additional part protrudes from the first surface so that the first side extends out of the receiving groove.

[0033] In the above technical solution, a receiving groove for receiving the additional part is provided on the first surface of the main body facing the electrode lead-out part, and the additional part protrudes from the first surface in the first direction, so that the first side surface can extend from the inside of the receiving groove to the outside of the receiving groove. The current collecting component adopting such a structure can, on the one hand, reduce the space occupied by the current collecting component in the first direction and reduce the weight of the current collecting component, which is beneficial to optimize the weight of the battery cell and the size in the first direction to improve the energy density of the battery cell. On the other hand, part of the first side surface is in the receiving groove and the other part is outside the receiving groove, that is, the first surface has the first side surface on both sides in the first direction, which is beneficial to improve the welding effect between the first surface and the first side surface, so as to improve the welding quality between the additional part and the main body.

[0034] In some embodiments, along the first direction, the depth of the accommodating groove is H1, and the thickness of the additional portion is H2, satisfying H2-H1≥0.2H2.

[0035] In the above technical solution, by setting the difference between the thickness of the additional part in the first direction and the depth of the accommodating groove in the first direction to be greater than or equal to 0.2 times the thickness of the additional part in the first direction, that is, the size of the portion of the additional part protruding from the first surface in the first direction is greater than or equal to 0.2 times the thickness of the additional part in the first direction, it is helpful to alleviate the phenomenon that the weld mark formed by welding the first surface and the first side surface exceeds the side of the additional part facing the electrode lead-out part in the first direction, thereby effectively reducing the risk of poor contact or loss of contact between the additional part and the electrode lead-out part due to the interference of the weld mark formed by welding the additional part and the main body, so as to alleviate the phenomenon of cold welding or poor welding between the additional part and the electrode lead-out part, and thus effectively improve the welding quality between the additional part and the electrode lead-out part.

[0036] In some embodiments, the first side surface abuts against a groove side surface of the accommodating groove.

[0037] In the above technical solution, the accommodating groove is arranged on the first surface, and the first side surface and the groove side surface of the accommodating groove abut each other, thereby reducing the gap between the first side surface and the first surface, which is beneficial to improving the welding quality between the first side surface and the first surface.

[0038] In some embodiments, the additional portion is welded to the main body portion to form at least one first welding portion, and the main body portion is welded to the pole tab to form at least one second welding portion; wherein the projections of the at least one first welding portion and the at least one second welding portion in a plane perpendicular to the first direction do not overlap.

[0039] In the above technical solution, the first welding portion formed by welding the additional portion and the main body portion and the second welding portion formed by welding the main body portion and the pole lug are arranged so that their projections in the first direction do not overlap with each other, so that the first welding portion and the second welding portion are staggered structures in the first direction, thereby reducing the occurrence of a molten pool between the first welding portion and the second welding portion, which is beneficial to improving the welding quality between the additional portion and the main body portion and between the main body portion and the pole lug.

[0040] In some embodiments, the additional portion surrounds an outer side of the second welding portion.

[0041] In the above technical solution, the additional part is arranged to surround the outer side of the second welding part formed by welding the main body and the pole tab, that is, the second welding part formed by welding the main body and the pole tab is located on the inner circumference of the additional part, which helps to shorten the current path between the pole tab and the current collecting component.

[0042] In some embodiments, the at least one second welding portion includes two second welding portions, the additional portion surrounds an outer side of one of the second welding portions, and the other second welding portion surrounds an outer side of the additional portion.

[0043] In the above technical solution, two second welding parts are formed by welding the main body and the pole ear, and one of the two second welding parts is located on the inner peripheral side of the additional part, and the other second welding part is located on the outer peripheral side of the additional part, which is beneficial to further improve the flow efficiency between the pole ear and the current collecting component.

[0044] In some embodiments, the additional portion is welded to the main body portion to form at least one first welding portion, and the additional portion is welded to the electrode lead-out portion to form at least one third welding portion; wherein the projections of the at least one first welding portion and the at least one third welding portion in a plane perpendicular to the first direction do not overlap.

[0045] In the above technical solution, the first welding portion formed by welding the additional portion to the main portion and the third welding portion formed by welding the additional portion to the electrode lead-out portion are arranged so that their projections in the first direction do not overlap with each other, so that the first welding portion and the third welding portion are staggered structures in the first direction, thereby reducing the occurrence of a molten pool between the first welding portion and the third welding portion, which is beneficial to improving the welding quality between the additional portion and the main portion and between the additional portion and the electrode lead-out portion.

[0046] In some embodiments, the third welding portion penetrates the electrode lead-out portion along the first direction.

[0047] In the above technical solution, by setting the third welding part to a structure that penetrates the electrode lead-out part in the first direction, on the one hand, the connection reliability between the additional part and the electrode lead-out part can be improved, and on the other hand, it is convenient to weld the additional part and the electrode lead-out part from the outside of the electrode lead-out part, which is beneficial to reducing the difficulty of welding.

[0048] In some embodiments, the third welding portion is configured to be formed by irradiating a laser from a side of the electrode lead portion facing away from the electrode assembly to melt at least a portion of the electrode lead portion and the additional portion.

[0049] In the above technical solution, the third welding portion is formed by laser welding on the outer side of the electrode lead-out portion, which is beneficial to reduce the welding difficulty between the additional portion and the electrode lead-out portion, so as to improve the assembly efficiency of the battery cell.

[0050] In some embodiments, the third welding portion does not penetrate the additional portion along the first direction.

[0051] In the above technical solution, by setting the third welding part as a structure that does not penetrate the additional part along the first direction, on the one hand, the welding power required for welding the additional part and the electrode lead-out part can be reduced, which is beneficial to reducing the welding difficulty; on the other hand, the adverse effects on the main body and the electrode ear caused by the third welding part penetrating the additional part can be alleviated.

[0052] In some embodiments, the additional portion is welded to the main portion to form at least one first welding portion, the main portion is welded to the pole tab to form at least one second welding portion, and the additional portion is welded to the electrode lead portion to form at least one third welding portion; wherein, the projection area of ​​the at least one first welding portion in a plane perpendicular to the first direction is S1, the projection area of ​​the at least one second welding portion in a plane perpendicular to the first direction is S2, and the projection area of ​​the at least one third welding portion in a plane perpendicular to the first direction is S3, satisfying 0.8≤S1 / S2≤1.2; and / or, 0.8≤S1 / S3≤1.2; and / or, 0.8≤S2 / S3≤1.2.

[0053] In the above technical solution, by setting the projection area of ​​at least one first welding part in a plane perpendicular to the first direction, the projection area of ​​at least one second welding part in a plane perpendicular to the first direction and the projection area of ​​at least one third welding part in a plane perpendicular to the first direction to a ratio of 0.8 to 1.2, it is achieved that the projection area of ​​at least one first welding part in a plane perpendicular to the first direction, the projection area of ​​at least one second welding part in a plane perpendicular to the first direction and the projection area of ​​at least one third welding part in a plane perpendicular to the first direction are close to each other, so that on the one hand, the phenomenon that the overall flow capacity is bottlenecked or restricted due to the small projection area of ​​one of the first welding part, the second welding part and the third welding part in the first direction can be alleviated, and on the other hand, the phenomenon that the local flow capacity is excessive due to the large projection area of ​​one of the first welding part, the second welding part and the third welding part in the first direction can be alleviated, so as to reduce unnecessary waste and reduce the production cost of battery cells.

[0054] In some embodiments, the additional portion is welded to the main body portion to form at least one first welding portion, which is an annular structure; and / or, the main body portion is welded to the pole ear to form at least one third welding portion, which is an annular structure.

[0055] In the above technical solution, by setting the first welding portion formed by mutually welding the additional portion and the main body portion to an annular structure, it is beneficial to improve the connection stability between the additional portion and the main body portion, and it is beneficial to improve the flow area and flow balance between the additional portion and the main body portion, so as to improve the flow effect between the additional portion and the main body portion. Similarly, by setting the third welding portion formed by mutually welding the main body portion and the pole ear to an annular structure, it is beneficial to improve the connection stability between the main body portion and the pole ear, and it is beneficial to improve the flow area and flow balance between the main body portion and the pole ear, so as to improve the flow effect between the main body portion and the pole ear.

[0056] In some embodiments, the tab is disposed at one end of the main body facing the body portion.

[0057] In the above technical solution, by arranging the pole ear to be located on the side of the main body facing the main body of the current collecting component in the first direction, the pole ear and the main body are arranged facing each other in the first direction, thereby facilitating the welding of the main body of the current collecting component and the pole ear of the electrode assembly, which is beneficial to reducing the difficulty of assembling between the current collecting component and the pole ear.

[0058] In some embodiments, the body is cylindrical.

[0059] In the above technical solution, the main body of the electrode assembly is set as a cylindrical structure to facilitate subsequent processing to form a cylindrical battery cell, so that the battery cell has the advantages of high capacity, long cycle life, and a wide range of ambient temperature.

[0060] In some embodiments, the housing assembly comprises a housing, and the electrode assembly is accommodated in the housing; wherein the housing has a wall portion, and the wall portion is the electrode lead-out portion.

[0061] In the above technical solution, the shell assembly is provided with a shell, and the wall of the shell is used as the electrode lead-out portion, so that the electrode ear is connected to the wall of the shell through the current collecting component to realize the input or output of electrical energy of the battery cell. The structure is simple and easy to assemble.

[0062] In some embodiments, a convex portion is formed on a side of the wall portion facing the electrode assembly, and the convex portion is welded to the additional portion.

[0063] In the above technical solution, a convex portion is formed on the side of the wall portion facing the electrode assembly, and the convex portion is welded to the additional portion of the current collecting component to achieve a welding connection between the additional portion and the wall portion. A battery cell with such a structure facilitates welding connection after the wall portion and the additional portion of the current collecting component abut against each other through the convex portion, which helps to reduce the difficulty of welding between the additional portion and the wall portion.

[0064] In some embodiments, a groove is formed on a side of the wall portion facing away from the electrode assembly and corresponding to a position of the protrusion.

[0065] In the above technical solution, a groove is formed on the side of the wall portion away from the electrode assembly and at the position corresponding to the convex portion, so that the wall portion has a concave-convex structure formed by stamping, thereby forming a convex portion and a groove on both sides of the wall portion respectively, which is beneficial to reduce the processing difficulty and improve the processing efficiency. The wall portion with such a structure can effectively improve the structural strength of the wall portion to alleviate the deformation phenomenon when the wall portion and the additional portion are welded to each other, which is beneficial to improve the production quality of the battery cell.

[0066] In some embodiments, the housing assembly further comprises a housing, and the electrode assembly is accommodated in the housing; wherein the housing has a wall portion, and the electrode lead portion is insulated and mounted on the wall portion.

[0067] In the above technical solution, the shell assembly is also provided with a shell, and the electrode lead-out part is insulated and installed on the wall of the shell, so that the input or output of electric energy of the battery cell can be realized through the electrode lead-out part. The battery cell adopting this structure can reduce the risk of short circuit between the electrode lead-out part and the shell.

[0068] In some embodiments, the outer shell includes a shell and an end cover; the interior of the shell forms a receiving cavity with an opening, and the electrode assembly is received in the receiving cavity; the end cover closes the opening; wherein the end cover is the wall portion.

[0069] In the above technical solution, the wall portion of the shell is an end cover used to close the opening of the shell. The battery cell adopting this structure is convenient for assembling the current collecting component, which is beneficial to reduce the difficulty of connecting the current collecting component with the electrode lead-out portion and between the current collecting component and the pole ear, thereby improving the production efficiency of the battery cell.

[0070] 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, one end of the side wall is connected to the wall portion, and the other end of the side wall forms an opening opposite to the wall portion, and the side wall and the wall portion jointly define a accommodating cavity for accommodating the electrode assembly; the end cover closes the opening.

[0071] In the above technical solution, by setting the wall portion as a wall arranged opposite to the shell and the end cover, the battery cell adopting this structure can make the components such as the current collecting member away from the end cover, and make there be no direct connection relationship between the wall portion and the end cover, thereby alleviating the phenomenon that the force generated by the pulling or twisting of the wall portion by the current collecting member and other components acts on the end cover, so as to reduce the risk of connection failure between the end cover and the shell, which is beneficial to further reduce the risk of leakage of the battery cell during use.

[0072] In a second aspect, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.

[0073] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. 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 related drawings can be obtained based on these drawings without paying creative work.

[0075] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0076] Figure 2 An exploded view of the structure of a battery provided in some embodiments of the present application;

[0077] Figure 3A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0078] Figure 4 An exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0079] Figure 5 A partial cross-sectional view of a battery cell provided for some embodiments of the present application;

[0080] Figure 6 for Figure 5 A partial enlarged view of the battery cell at A shown;

[0081] Figure 7 A schematic diagram of the structure of a current collecting component provided in some embodiments of the present application;

[0082] Figure 8 A cross-sectional view of a current collecting component provided in some embodiments of the present application;

[0083] Fig. 9 for Figure 8 A partial enlarged view of the B portion of the current collecting member shown;

[0084] Fig.10 A schematic diagram of the structure of a current collecting component provided in some other embodiments of the present application;

[0085] Fig.11 A cross-sectional view of a current collecting component provided in some other embodiments of the present application;

[0086] Fig.12 A schematic diagram of welding the current collecting member, the electrode tab and the electrode lead-out portion provided in some embodiments of the present application;

[0087] Fig.13 A schematic diagram of the structure of a battery cell provided in some other embodiments of the present application;

[0088] Fig.14 An exploded view of the structure of a battery cell provided in some other embodiments of the present application;

[0089] Fig.15 Partial cross-sectional views of battery cells provided for some other embodiments of the present application.

[0090] Icons: 1000-vehicle; 100-battery; 10-casing; 11-first casing body; 12-second casing body; 20-battery cell; 21-casing assembly; 211-electrode lead-out portion; 212-casing; 2121-wall portion; 2121a-convex portion; 2121b-recess; 2122-casing; 2122a-opening; 2123-end cap; 22-electrode assembly; 221-main body; 222-ear; 23-current collecting member; 231-main body; 2311-first surface; 2312-accommodating groove; 2313-center through hole; 232-additional portion; 2321-first side surface; 2322-second surface; 233-first welding portion; 24-second welding portion; 25-third welding portion; 200-controller; 300-motor; X-first direction; Y-second direction. DETAILED DESCRIPTION

[0091] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0092] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. 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 and secondary relationship.

[0093] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0094] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0095] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0096] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0097] The term "plurality" used in the present application refers to two or more (including two).

[0098] 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.

[0099] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0100] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0101] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet 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.

[0102] 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 disposed on either or both of the two facing surfaces of the positive electrode current collector.

[0103] 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 or stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc., treated with silver surface, may be used. The composite current collector may include a polymer material base 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.).

[0104] 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 positive electrode active materials for batteries 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.

[0105] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0106] As an example, the negative electrode current collector can be a metal foil, a foamed metal or a composite current collector. For example, as a metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The foamed metal can be a foamed nickel, a foamed copper, a foamed aluminum, a foamed alloy, or a foamed carbon, etc. The composite current collector can include a polymer material base and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0107] 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.

[0108] 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 disposed on either or both of the two facing surfaces of the negative electrode current collector.

[0109] As an example, the negative electrode active material may adopt the negative electrode active material for battery cells 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.

[0110] 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.

[0111] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0112] In some embodiments, the separator is a separator membrane. There may be many types of separator membranes, and any known porous separator membrane with good chemical stability and mechanical stability may be selected.

[0113] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0114] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0115] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The electrolyte may be in a liquid or gel state.

[0116] 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.

[0117] In some embodiments, the electrode assembly is a laminate structure.

[0118] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0119] In some embodiments, the electrode assembly is provided with tabs, which can lead current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0120] In some embodiments, the 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 (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0121] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell or a battery cell of other shapes. The prismatic battery cell includes but is not limited to a square shell battery cell, a blade-shaped battery cell, a polygonal prismatic battery, such as a hexagonal prismatic battery.

[0122] 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.

[0123] 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.

[0124] 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 accommodated in the case.

[0125] 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.

[0126] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0127] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient. They are an important part of the development of new energy today. With the rapid development and increasing demand for batteries, the demand for battery reliability has also increased.

[0128] For general battery cells, the outer shell of the battery cell usually includes a shell and an end cover, and the end cover covers the opening of the shell. In order to facilitate the assembly of the battery cell, especially in a battery cell with a cylindrical structure, the end cover is usually used as the power output electrode of the battery cell. The electrical connection between the electrode assembly and the end cover can be achieved by welding the electrode lugs of the electrode assembly and the end cover of the shell through the current collecting member arranged in the shell, so as to realize the input or output of electric energy of the battery cell. However, in a battery cell of this structure, the pole ear of the electrode assembly is usually made of copper or aluminum, etc., and the current collecting component and the pole ear are set to the same material to reduce the difficulty of welding between the pole ear and the current collecting component. In order to improve the structural strength of the outer shell, the outer shell is usually set to steel, etc., so that the pole ear of the electrode assembly and the end cover of the outer shell are made of different materials. This will cause the material between the current collecting component and the end cover to be different, resulting in different melting points and thermal expansion coefficients when the current collecting component and the end cover are welded to each other, thereby causing welding cracks between the current collecting component and the end cover, resulting in the risk of electrolyte leakage in the battery cell during use, which in turn causes a large safety hazard in the battery cell during use, which is not conducive to the reliability of the battery cell.

[0129] Based on the above considerations, in order to solve the problem of low reliability of battery cells during use, an embodiment of the present application provides a battery cell, which includes a housing assembly, an electrode assembly and a current collecting component. The housing assembly includes an electrode lead-out portion for inputting or outputting electrical energy. The electrode assembly is accommodated in the housing assembly, and the electrode assembly includes a main body and a pole ear, and the pole ear is arranged in the main body, and the pole ear and the electrode lead-out portion are made of different materials. The current collecting component is arranged in the housing assembly, and the current collecting component includes a main body portion made of the same material as the pole ear and an additional portion made of the same material as the electrode lead-out portion, the main body portion is connected to the additional portion, the main body portion is welded to the pole ear, and the additional portion is welded to the electrode lead-out portion.

[0130] In a battery cell of this structure, the current collecting member is provided as a main body portion and an additional portion which are connected to each other, the main body portion is welded to the pole lug, and the additional portion is welded to the electrode lead-out portion of the housing assembly to achieve electrical connection between the electrode assembly and the electrode lead-out portion, thereby enabling input or output of electrical energy of the battery cell, wherein the material of the main body portion is provided to be the same as the material of the pole lug, and the material of the additional portion is provided to be the same as the material of the electrode lead-out portion, so that the battery cell of this structure is convenient for welding connection between the current collecting member and the electrode lead-out portion and between the current collecting member and the pole lug, which is beneficial to reducing the difficulty of assembling between the current collecting member and the electrode lead-out portion and between the current collecting member and the pole lug of the electrode assembly, thereby improving the assembly efficiency of the battery cell, and on the other hand, it is possible to achieve mutual welding between the current collecting member and the electrode lead-out portion with the same material, thereby alleviating the phenomenon of different melting points and different thermal expansion coefficients caused by welding between the current collecting member and the electrode lead-out portion due to different materials, thereby reducing the phenomenon of welding cracks between the current collecting member and the electrode lead-out portion, thereby reducing the risk of leakage of the battery cell, thereby improving the reliability of the battery cell.

[0131] The battery cells disclosed in the embodiments of the present application can be used, but not limited to, in electrical devices such as vehicles, ships or aircraft. A power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical device, which is helpful to alleviate the problem of electrolyte leakage in the battery cells during use, thereby improving the reliability of the battery cells.

[0132] The embodiment of the present application provides an electric device using a battery as a power source, and the electric device may be, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, etc. Among them, 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., and the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0133] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0134] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 may be provided 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 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source or a power source for the vehicle 1000, etc. The vehicle 1000 may also include a controller 200 and a motor 300, and the controller 200 is used to control the battery 100 to power the motor 300, for example, for the starting, navigation and working power requirements of the vehicle 1000 during driving.

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

[0136] Please refer to Figure 2 and Figure 3 , Figure 2 The structure explosion diagram of the battery 100 provided in some embodiments of the present application is shown in FIG. Figure 3 The schematic diagram of the structure of the battery cell 20 provided in some embodiments of the present application. The battery 100 comprises a box body 10 and a battery cell 20 , and the battery cell 20 is used to be accommodated in the box body 10 .

[0137] The box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures. 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 cell 20. The second box body 12 may be a hollow structure with one end open, and the first box body 11 may 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 may 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.

[0138] 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, etc. Figure 2In the embodiment, the box body 10 is in the shape of a rectangular parallelepiped.

[0139] In the battery 100, the battery cell 20 disposed in the box 10 may be one or more. When there are more than one battery cell 20 disposed in the box 10, the multiple battery cells 20 may be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 20 are both connected in series and in parallel. The multiple battery cells 20 may be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 20 may be accommodated in the box 10; of course, the battery 100 may also be a battery module formed by first connecting multiple battery cells 20 in series, in parallel, or in mixed connection, and then the multiple battery modules may be connected in series, in parallel, or in mixed connection to form a whole, and then accommodated in the box 10.

[0140] 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 plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0141] Each battery cell 20 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 may be cylindrical, flat, rectangular or in other shapes. Figure 3 In the figure, the battery cell 20 is a cylindrical structure.

[0142] According to some embodiments of the present application, referring to Figure 3 , and please refer to Figure 4 , Figure 5 and Figure 6 , Figure 4 This is an exploded view of the structure of the battery cell 20 provided in some embodiments of the present application. Figure 5 A partial cross-sectional view of a battery cell 20 provided in some embodiments of the present application, Figure 6 for Figure 5 A partial enlarged view of the battery cell 20 at A shown. The present application provides a battery cell 20, which includes a housing assembly 21, an electrode assembly 22 and a current collecting member 23. The housing assembly 21 includes an electrode lead-out portion 211 for inputting or outputting electrical energy. The electrode assembly 22 is accommodated in the housing assembly 21, and the electrode assembly 22 includes a main body 221 and a pole ear 222, and the pole ear 222 is arranged on the main body 221, and the pole ear 222 and the electrode lead-out portion 211 are made of different materials. The current collecting member 23 is arranged in the housing assembly 21, and the current collecting member 23 includes a main body 231 of the same material as the pole ear 222 and an additional portion 232 of the same material as the electrode lead-out portion 211, the main body 231 is connected to the additional portion 232, the main body 231 is welded to the pole ear 222, and the additional portion 232 is welded to the electrode lead-out portion 211.

[0143] The housing assembly 21 includes a housing 212, and the electrode assembly 22 and the current collecting member 23 are both contained in the housing 212. The housing 212 can also be used to contain an electrolyte, such as an electrolyte. The housing 212 can be in a variety of structural forms, such as a cylinder or a cuboid. Similarly, the housing 212 can also be made of a variety of materials, such as copper, iron, aluminum, steel or aluminum alloy.

[0144] The housing assembly 21 includes an electrode lead-out portion 211 for inputting or outputting electric energy. The electrode lead-out portion 211 is electrically connected to the pole ear 222 of the electrode assembly 22, thereby outputting or inputting electric energy of the battery cell 20. The electrode lead-out portion 211 can be the positive electrode of the output battery cell 20, that is, the electrode lead-out portion 211 is the positive output electrode of the battery cell 20, or it can be the negative electrode of the output battery cell 20, that is, the electrode lead-out portion 211 is the negative output electrode of the battery cell 20. Similarly, the structure of the electrode lead-out portion 211 can be various. The electrode lead-out portion 211 can be a wall portion 2121 of the housing 212, or it can be an electrode terminal installed on the wall portion 2121 of the housing 212. For example, in Figure 4 and Figure 5 In the embodiment, the electrode lead-out portion 211 is a wall portion 2121 of the housing 212 .

[0145] In some embodiments, the housing 212 may include a shell 2122 and an end cap 2123, wherein a accommodating cavity is formed inside the shell 2122, and the accommodating cavity is used to accommodate the electrode assembly 22, and the accommodating cavity has an opening 2122a, that is, the shell 2122 is a hollow structure with an opening 2122a at one end, and the end cap 2123 covers the opening 2122a of the shell 2122 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.

[0146] When assembling the battery cell 20 , the electrode assembly 22 may be placed into the shell 2122 first, and the shell 2122 may be filled with electrolyte. The end cap 2123 may then be closed over the opening 2122 a of the shell 2122 to complete the assembly of the battery cell 20 .

[0147] It should be noted that the wall portion 2121 for mounting the electrode lead-out portion 211 or the wall portion 2121 of the electrode lead-out portion 211 may be the end cover 2123 or a wall of the housing 2122. Figure 4 and Figure 5 In the embodiment, the wall portion 2121 is the end cap 2123. Of course, the structure of the battery cell 20 is not limited thereto, and in other embodiments, the wall portion 2121 may also be a bottom wall of the housing 2122 and the end cap 2123 disposed opposite to each other, or a side wall of the housing 2122 and the end cap 2123 adjacent to and abutting against each other.

[0148] It should be noted that, when the electrode lead-out portion 211 is an electrode terminal installed on the wall portion 2121 of the outer shell 212, the electrode lead-out portion 211 is insulated and installed on the outer shell 212, then the output pole of the battery cell 20 with opposite polarity to the electrode lead-out portion 211 may be the shell 2122 of the outer shell 212, or it may be the end cover 2123 of the outer shell 212; when the electrode lead-out portion 211 is the shell 2122 of the outer shell 212, then the output pole of the battery cell 20 with opposite polarity to the electrode lead-out portion 211 may be the electrode terminal insulated and installed on the wall portion 2121 of the outer shell 212, or it may be the end cover 2123 insulated and connected to the shell 2122; when the electrode lead-out portion 211 is the end cover 2123 of the outer shell 212, then the output pole of the battery cell 20 with opposite polarity to the electrode lead-out portion 211 may be the electrode terminal insulated and installed on the wall portion 2121 of the outer shell 212, or it may be the shell 2122 insulated and connected to the end cover 2123.

[0149] The shell 2122 can be in various shapes, such as a cylinder, a cuboid, or a prism structure. The shape of the shell 2122 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, a shell 2122 with a cylindrical structure can be selected; if the electrode assembly 22 is a cuboid structure, a shell 2122 with a cuboid structure can be selected. Of course, the structure of the end cap 2123 can also be various, for example, the end cap 2123 is a plate-like structure or a hollow structure with one end open. For example, in Figure 3 In the embodiment, the shell 2122 is a cylindrical structure.

[0150] Of course, it is understandable that the outer shell 212 is not limited to the above structure, and the outer shell 212 may also be other structures. For example, the outer shell 212 may include a shell body 2122 and two end caps 2123. The shell body 2122 is a hollow structure with openings 2122a on opposite sides. One end cap 2123 corresponds to an opening 2122a of the shell body 2122 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte. That is, the shell body 2122 is formed with openings 2122a on opposite sides, and the two end caps 2123 are respectively covered on both sides of the shell body 2122 to close the corresponding openings 2122a.

[0151] The electrode assembly 22 is a component in the battery cell 20 where an electrochemical reaction occurs. The main body 221 of the electrode assembly 22 may include a positive electrode sheet, a negative electrode sheet, and a separator. The structure of the electrode assembly 22 may be various. For example, the main body 221 of the electrode assembly 22 may be a winding structure formed by winding a positive electrode sheet, a separator, and a negative electrode sheet, or a stacked structure formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet. The tabs 222 of the electrode assembly 22 are components formed by stacking and connecting regions on the positive electrode sheet that are not coated with a positive electrode active material layer, or components formed by stacking and connecting regions on the negative electrode sheet that are not coated with a negative electrode active material layer.

[0152] Wherein, the isolating element is an isolating membrane, and the main material of the isolating membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0153] For example, in Figure 4 In the embodiment, the main body 221 of the electrode assembly 22 is a wound structure formed by winding a positive electrode sheet, a separator and a negative electrode sheet, and the main body 221 of the electrode assembly 22 is cylindrical.

[0154] Each electrode assembly 22 has two tabs 222, and the polarities of the two tabs 222 are opposite, that is, the two tabs 222 are respectively used to output or input the positive electrode and the negative electrode of the electrode assembly 22. If the tabs 222 are used to output the positive electrode of the electrode assembly 22, the tabs 222 are components formed by mutually stacking and connecting the regions on the positive electrode sheet that are not coated with the positive electrode active material layer; if the tabs 222 are used to output the negative electrode of the electrode assembly 22, the tabs 222 are components formed by mutually stacking and connecting the regions on the negative electrode sheet that are not coated with the negative electrode active material layer.

[0155] The material of the tab 222 is different from that of the electrode lead 211, that is, the main component of the tab 222 is different from the main component of the electrode lead 211, wherein the main component of the tab 222 is the component that accounts for more than 50% of the components of the tab 222, and similarly, the main component of the electrode lead 211 is the component that accounts for more than 50% of the components of the electrode lead 211. The tab 222 can also be made of a variety of materials, such as copper or aluminum. If the tab 222 is a positive tab 222, the material of the tab 222 is usually aluminum, that is, the main component of the tab 222 is aluminum, and the content is more than 50%; if the tab 222 is a negative tab 222, the material of the tab 222 is usually copper, that is, the main component of the tab 222 is copper, and the content is more than 50%. That is to say, the difference in material between the pole lug 222 and the electrode lead-out portion 211 means that the main component of the pole lug 222 is different from the main component of the electrode lead-out portion 211. For example, if the pole lug 222 and the electrode lead-out portion 211 are both made of a single material, such as copper or aluminum, then the material of the pole lug 222 and the electrode lead-out portion 211 are composed of different metal elements; if the pole lug 222 and the electrode lead-out portion 211 are made of an alloy material or a mixed material, such as aluminum alloy or steel, then the difference in material between the pole lug 222 and the electrode lead-out portion 211 means that the main components of the pole lug 222 and the electrode lead-out portion 211 are different, that is, the components with a content of more than 50% in the alloy material or the mixed material are different.

[0156] The current collecting component 23 includes an additional portion 232 made of the same material as the electrode lead-out portion 211 and a main body portion 231 made of the same material as the electrode tab 222. The additional portion 232 is connected to the main body portion 231, that is, the current collecting component 23 includes an additional portion 232 and a main body portion 231 made of different materials, which are connected to each other so that an electrical connection is formed between the additional portion 232 and the main body portion 231.

[0157] Optionally, the electrode lead-out portion 211 may be made of a variety of materials, such as copper, iron, aluminum, steel or aluminum alloy. Figure 5 and Figure 6 In the embodiment, the electrode lead-out portion 211 is a wall portion 2121 of the outer shell 212, and the outer shell 212 may be made of steel. Correspondingly, the material of the additional portion 232 of the current collecting member 23 is the same as that of the outer shell 212, that is, the material of the additional portion 232 of the current collecting member 23 is also steel. Similarly, if the tab 222 is a positive tab 222, the tab 222 is usually made of aluminum, and the corresponding body portion 231 of the current collecting member 23 is made of aluminum; if the tab 222 is a negative tab 222, the tab 222 is usually made of copper, and the corresponding body portion 231 of the current collecting member 23 is made of copper.

[0158] It should be noted that the same material as the electrode lead-out portion 211 and the additional portion 232 means that the main component of the electrode lead-out portion 211 is the same as the main component of the additional portion 232, wherein the main component of the additional portion 232 is the component that accounts for more than 50% of the components of the additional portion 232, and similarly, the main component of the electrode lead-out portion 211 is the component that accounts for more than 50% of the components of the electrode lead-out portion 211. For example, if the electrode lead-out portion 211 and the additional portion 232 are both made of a single material, such as copper or aluminum, then the electrode lead-out portion 211 and the additional portion 232 are composed of the same metal element; if the electrode lead-out portion 211 and the additional portion 232 are made of an alloy material or a mixed material, such as aluminum alloy or steel, then the different materials of the electrode lead-out portion 211 and the additional portion 232 mean that the main component of the electrode lead-out portion 211 and the additional portion 232 is the same, that is, the component that accounts for more than 50% of the alloy material or the mixed material is the same, for example, low carbon steel, medium carbon steel and high carbon steel are all of the same material. Similarly, the same material as the tab 222 and the main body 231 means that the main component of the tab 222 is the same as the main component of the main body 231. For example, the tab 222 and the main body 231 are both made of a single material, such as copper or aluminum, then the tab 222 and the main body 231 are composed of the same metal element; if the tab 222 and the main body 231 are made of an alloy material or a mixed material, such as an aluminum alloy or steel, then the different materials of the tab 222 and the main body 231 mean that the main component of the tab 222 and the main body 231 is the same, that is, the component with a content of more than 50% in the alloy material or the mixed material is the same, for example, low carbon steel, medium carbon steel and high carbon steel are all of the same material.

[0159] Optionally, the connection between the additional part 232 and the main body 231 of the current collecting member 23 can be in various ways, such as clamping, bolting, laser welding, plating, friction welding, or ultrasonic connection. Even if the additional part 232 and the main body 231 of the current collecting member 23 with such a structure are made of different materials and welded to each other to form welding cracks, the welding cracks between the additional part 232 and the main body 231 are located in the housing 212 of the housing assembly 21, and will not affect the housing 212, thereby reducing the risk of leakage.

[0160] In some embodiments, the battery cell 20 may also include a pressure relief mechanism, which is installed on the outer shell 212. Optionally, the pressure relief mechanism may be arranged on the end cover 2123 or on the shell 2122. The pressure relief mechanism is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0161] Exemplarily, the pressure relief mechanism may be a pressure relief component such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve or a safety valve.

[0162] The current collecting member 23 is provided with a main body portion 231 and an additional portion 232 connected to each other, the main body portion 231 is welded to the pole ear 222, and the additional portion 232 is welded to the electrode lead-out portion 211 of the housing assembly 21, so as to realize the electrical connection between the electrode assembly 22 and the electrode lead-out portion 211, thereby realizing the input or output of the electric energy of the battery cell 20, wherein the material of the main body portion 231 is set to be the same as the material of the pole ear 222, and the material of the additional portion 232 is set to be the same as the material of the electrode lead-out portion 211, so that the battery cell 20 of this structure is convenient for the current collecting member 23 and the electrode lead-out portion 211, and the current collecting member 23 and the electrode lead-out portion 211. The welding connection of the pole ear 222 is beneficial to reduce the difficulty of assembling between the current collecting component 23 and the electrode lead-out portion 211 and between the current collecting component 23 and the pole ear 222 of the electrode assembly 22, so as to improve the assembly efficiency of the battery cell 20. On the other hand, it can realize the mutual welding of the current collecting component 23 and the electrode lead-out portion 211 with the same material, so as to alleviate the phenomenon of different melting points and thermal expansion coefficients caused by welding the current collecting component 23 and the electrode lead-out portion 211 due to different materials, thereby reducing the phenomenon of welding cracks between the current collecting component 23 and the electrode lead-out portion 211, which is beneficial to reduce the risk of leakage of the battery cell 20, so as to improve the reliability of the battery cell 20.

[0163] According to some embodiments of the present application, referring to Figure 6 , and please refer to Figure 7 and Figure 8 , Figure 7 This is a schematic diagram of the structure of the current collecting component 23 provided in some embodiments of the present application. Figure 8 A cross-sectional view of a current collecting member 23 provided in some embodiments of the present application. Along the first direction X, at least a portion of the current collecting member 23 is disposed between the electrode assembly 22 and the electrode lead-out portion 211. Along the first direction X, the additional portion 232 is connected to a side of the body portion 231 away from the electrode assembly 22.

[0164] The first direction X is the thickness direction of the current collecting member 23 . Similarly, the first direction X is also the thickness direction of the additional portion 232 and the thickness direction of the main body portion 231 .

[0165] Along the first direction X, at least a portion of the current collecting component 23 is disposed between the electrode assembly 22 and the electrode lead-out portion 211, that is, the electrode assembly 22 and the electrode lead-out portion 211 are arranged along the first direction X, and at least a portion of the current collecting component 23 is located between the electrode assembly 22 and the electrode lead-out portion 211. Optionally, the current collecting component 23 may be entirely located between the electrode assembly 22 and the electrode lead-out portion 211, or only partially located between the electrode assembly 22 and the electrode lead-out portion 211.

[0166] The additional portion 232 is connected to the side of the main body 231 away from the electrode assembly 22, that is, in the first direction X, the additional portion 232 is arranged on the side of the main body 231 away from the electrode assembly 22, and the side of the main body 231 facing the electrode assembly 22 is closer to the electrode assembly 22 than the side of the additional portion 232 facing the electrode assembly 22. Optionally, the structure in which the additional portion 232 is connected to the side of the main body 231 away from the electrode assembly 22 may be various, for example, the additional portion 232 and the main body 231 may be stacked along the first direction X, and the additional portion 232 may be located on the side of the main body 231 facing the electrode lead-out portion 211, or at least a portion of the additional portion 232 may be embedded in the main body 231 from the side of the main body 231 facing the electrode lead-out portion 211.

[0167] For example, in Figure 8 In the embodiment, a portion of the additional portion 232 is embedded in the main body 231 from a side of the main body 231 facing the electrode lead-out portion 211 .

[0168] By disposing at least a portion of the current collecting component 23 between the electrode assembly 22 and the electrode lead-out portion 211, and the additional portion 232 is disposed on the side of the main body 231 away from the electrode assembly 22 in the first direction X, the additional portion 232 of the current collecting component 23 and the main body 231 are structures arranged along the first direction X, and the additional portion 232 is disposed facing the electrode lead-out portion 211, thereby facilitating the welding of the additional portion 232 of the current collecting component 23 and the electrode lead-out portion 211 of the shell assembly 21, and facilitating the welding of the main body 231 of the current collecting component 23 and the pole ear 222 of the electrode assembly 22, which is beneficial to reducing the difficulty of assembling the electrode lead-out portion 211 and the pole ear 222 connected to the current collecting component 23, so as to improve the assembly efficiency of the battery cell 20.

[0169] According to some embodiments of the present application, referring to Figure 7 and Figure 8 , and please refer to Fig. 9 , Fig. 9 for Figure 8 The enlarged partial view of the current collecting member 23 at B is shown. Along the first direction X, the body portion 231 has a first surface 2311 facing the electrode lead-out portion 211 , and the first surface 2311 is provided with a receiving groove 2312 , and at least a part of the additional portion 232 is received in the receiving groove 2312 .

[0170] The first surface 2311 is provided with a receiving groove 2312 , that is, the side of the main body 231 facing the electrode assembly 22 in the first direction X is provided with the receiving groove 2312 .

[0171] Optionally, the receiving groove 2312 may penetrate the main body 231 along the first direction X, or may not penetrate the main body 231 along the first direction X. For example, Fig. 9 In the embodiment, the receiving groove 2312 does not penetrate the main body 231 in the first direction X.

[0172] At least part of the additional part 232 is accommodated in the accommodating groove 2312 , that is, in the first direction X, the additional part 232 may be completely accommodated in the accommodating groove 2312 , or part of the additional part 232 may be accommodated in the accommodating groove 2312 and the other part may extend out of the accommodating groove 2312 .

[0173] For example, in Figure 8 In the embodiment, along the first direction X, part of the additional portion 232 is received in the receiving groove 2312 , and the other part protrudes from the first surface 2311 .

[0174] It should be noted that, in some embodiments, the first surface 2311 of the main body 231 facing the electrode assembly 22 may not be provided with the receiving groove 2312, and the additional part 232 only needs to be connected to the first surface 2311. For example, referring to Fig.10 and Fig.11 , Fig.10 This is a schematic diagram of the structure of the current collecting component 23 provided in some other embodiments of the present application, Fig.11 The following are cross-sectional views of current collecting members 23 provided in some other embodiments of the present application. Along the first direction X, the body portion 231 has a first surface 2311 facing the electrode lead portion 211, and the additional portion 232 is connected to the first surface 2311, so that the body portion 231 and the additional portion 232 are stacked along the first direction X.

[0175] By providing a receiving groove 2312 on the first surface 2311 of the main body 231 facing the electrode lead-out portion 211, and at least a portion of the additional portion 232 is received in the receiving groove 2312 of the main body 231, the space occupied by the current collecting component 23 in the first direction X can be reduced, and the weight of the current collecting component 23 can be reduced, which is beneficial to optimizing the weight of the battery cell 20 and the size in the first direction X, so as to improve the energy density of the battery cell 20.

[0176] In some embodiments, see Figure 6 , Figure 7 and Figure 8 As shown, along the first direction X, the additional portion 232 protrudes from the first surface 2311 , and the portion of the additional portion 232 protruding from the first surface 2311 is welded to the electrode lead portion 211 .

[0177] The portion of the additional portion 232 protruding from the first surface 2311 is welded to the electrode lead portion 211 , that is, in the first direction X, the portion of the additional portion 232 extending out of the receiving groove 2312 is welded to the electrode lead portion 211 after abutting against each other.

[0178] By setting the additional part 232 to protrude from the first surface 2311 of the main body part 231 in the first direction X, that is, the additional part 232 extends the accommodating groove 2312 in the first direction X, so that the portion of the additional part 232 extending from the accommodating groove 2312 can abut against the electrode lead-out part 211, thereby reducing the phenomenon of a gap between the additional part 232 and the electrode lead-out part 211 due to the interference of the main body part 231, which is beneficial to improving the contact effect between the additional part 232 and the electrode lead-out part 211, thereby alleviating the risk of cold welding or poor welding between the additional part 232 and the electrode lead-out part 211, and thus effectively improving the welding effect between the additional part 232 and the electrode lead-out part 211.

[0179] exist Figure 8 In the embodiment, the additional portion 232 is a structure protruding from the first surface 2311 along the first direction X, that is, the second surface 2322 of the additional portion 232 facing the electrode lead-out portion 211 in the first direction X and the first surface 2311 of the main body 231 are spaced apart in the first direction X. Of course, the structure of the current collecting member 23 is not limited thereto. In some embodiments, the current collecting member 23 may also be other structures. For example, along the first direction X, the additional portion 232 has a second surface 2322 facing the electrode lead-out portion 211, and the second surface 2322 is flush with the first surface 2311. That is, along the first direction X, the side of the additional portion 232 facing the electrode lead-out portion 211 and the side of the main body 231 facing the electrode lead-out portion 211 are mutually flush.

[0180] By arranging the second surface 2322 of the additional part 232 facing the electrode lead-out part 211 in the first direction X and the first surface 2311 of the main body part 231 facing the electrode lead-out part 211 in the first direction X to be flush, the thickness of the additional part 232 in the first direction X is made to be the same as the depth of the accommodating groove 2312 in the first direction X, thereby reducing the phenomenon of a gap between the additional part 232 and the electrode lead-out part 211 due to the interference of the main body part 231 and further optimizing the occupied space of the current collecting member 23 in the electrode lead-out part 211 and the electrode assembly 22, which is beneficial to improving the internal space utilization of the battery cell 20, and further improving the energy density of the battery cell 20.

[0181] According to some embodiments of the present application, see Figure 7 and Figure 8 As shown, the additional portion 232 is an annular structure. In other words, the additional portion 232 is an annular structure connected end to end in its extending direction.

[0182] Among them, the main body 231 is a disc structure, and the main body 231 and the additional part 232 are coaxially arranged to make the structure of the current collecting component 23 more regular, thereby facilitating the installation of the current collecting component 23 and helping to save the space occupied by the current collecting component 23 in the outer shell assembly 21, thereby improving the internal space utilization of the battery cell 20.

[0183] It should be noted that, in other embodiments, the additional portion 232 may also be a disc structure, a strip structure or an arc structure, etc., and the main body 231 may also be a rectangular disc structure, a triangular disc structure or an elliptical disc structure, etc. Similarly, the number of additional portions 232 disposed on the main body 231 may be one or more. Figure 7 In the embodiment, there is only one additional portion 232 disposed on the main body 231.

[0184] In some embodiments, the main body 231 is further provided with a central through hole 2313 that passes through both sides of the main body 231 along the first direction X. The central through hole 2313 is used to allow electrolyte to pass through, so that the electrolyte can pass through the central through hole 2313 along the first direction X and enter the electrode assembly 22, thereby facilitating the improvement of the electrolyte infiltration effect of the electrode assembly 22.

[0185] By setting the additional part 232 as a ring structure, it is beneficial to increase the welding area between the additional part 232 and the electrode lead-out part 211, so as to improve the connection stability between the additional part 232 and the electrode lead-out part 211, and the additional part 232 with a ring structure can improve the overcurrent balance between the current collecting component 23 and the electrode lead-out part 211, which is beneficial to reduce the phenomenon of large local overcurrent between the current collecting component 23 and the electrode lead-out part 211.

[0186] In some embodiments, see Figure 7 and Figure 8 As shown, the receiving groove 2312 is an annular groove extending along the extension direction of the additional portion 232 .

[0187] The receiving groove 2312 is an annular groove extending along the extension direction of the additional portion 232 , that is, the receiving groove 2312 is an annular structure connected end to end in its extension direction, so that the shape of the receiving groove 2312 matches the shape of the additional portion 232 .

[0188] By setting the receiving groove 2312 in an annular groove with the same extension direction as the additional part 232, on the one hand, it is convenient to accommodate the additional part 232 in the receiving groove 2312, and can play a certain limiting and positioning role for the additional part 232, which is beneficial to reduce the difficulty of assembly between the additional part 232 and the main body part 231. On the other hand, it is only necessary to set the annular receiving groove 2312 on the first surface 2311 to match the shape of the additional part 232, which is beneficial to reduce the processing difficulty of the receiving groove 2312 and reduce the processing range of the receiving groove 2312.

[0189] The structure of the current collecting component 23 is not limited to this. In other embodiments, the current collecting component 23 may also be other structures. For example, the current collecting component 23 may include a plurality of additional parts 232, and the plurality of additional parts 232 are all connected to the main body part 231. Along the first direction X, the projections of the plurality of additional parts 232 in a plane perpendicular to the first direction X do not overlap with each other.

[0190] Among them, along the first direction X, the projections of the multiple additional parts 232 in the plane perpendicular to the first direction X do not overlap with each other, that is, the multiple additional parts 232 are arranged at intervals in the plane perpendicular to the first direction X. For example, if the additional part 232 is a ring structure, the multiple additional parts 232 are structures that surround each other and are arranged at intervals in the radial direction of the current collecting component 23; if the additional part 232 is a strip structure, the multiple additional parts 232 are structures that are arranged at intervals in the direction perpendicular to the first direction X.

[0191] The current collecting component 23 is provided with a plurality of additional parts 232, and the plurality of additional parts 232 are all connected to the side of the main body 231 away from the electrode assembly 22, and the projections of the plurality of additional parts 232 in the first direction X do not overlap, so that after the plurality of additional parts 232 are welded to the electrode lead-out part 211, the flow efficiency between the current collecting component 23 and the electrode lead-out part 211 can be improved.

[0192] According to some embodiments of the present application, the main body portion 231 is connected to the additional portion 232 by welding.

[0193] The welding method between the main body 231 and the additional part 232 may be laser welding connection, coating connection, friction welding connection or ultrasonic connection, etc. Similarly, the welding position of the additional part 232 and the main body 231 may be various, for example, the area where the additional part 232 and the main body 231 overlap each other may be penetrated by welding along the first direction X, or the side of the additional part 232 may be connected to the main body 231 by fillet welding.

[0194] The main body 231 and the additional part 232 are connected by welding, which can effectively improve the connection strength and connection stability between the additional part 232 and the main body 231, so as to reduce the phenomenon of separation between the additional part 232 and the main body 231 during use, which is beneficial to improve the overcurrent stability between the additional part 232 and the main body 231, thereby effectively improving the use stability of the battery cell 20.

[0195] According to some embodiments of this application, see Figure 6 , Figure 8 and Fig. 9 As shown, along the first direction X, the current collecting member 23 is disposed between the electrode assembly 22 and the electrode lead-out portion 211. Along the first direction X, the body portion 231 has a first surface 2311 facing the electrode lead-out portion 211, and along the second direction Y, the additional portion 232 has a first side surface 2321, and the first side surface 2321 is welded to the first surface 2311, and the second direction Y is perpendicular to the first direction X.

[0196] In which, along the second direction Y, the additional part 232 has a first side surface 2321, and the first side surface 2321 is welded to the first surface 2311, that is, the side surface of the additional part 232 in the second direction Y perpendicular to the first direction X is welded to the first surface 2311 of the main body part 231, so as to form a corner welding connection relationship between the additional part 232 and the main body part 231.

[0197] exist Fig. 9 In the embodiment, the additional part 232 has two second surfaces 2322 arranged opposite to each other in the first direction X, that is, the additional part 232 forms two second surfaces 2322 on both sides of the thickness direction thereof, and one first surface 2311 of the two first surfaces 2311 close to the electrode lead-out part 211 in the first direction X is used for welding connection with the electrode lead-out part 211, so as to realize welding connection between the additional part 232 and the electrode lead-out part 211, and the two second surfaces 2322 are connected through the first side surface 2321. It should be noted that in the embodiment where the main body 231 is provided with the receiving groove 2312, one second surface 2322 of the two second surfaces 2322 abuts against the groove bottom surface of the receiving groove 2312, and the other second surface 2322 is welded to the electrode lead-out part 211.

[0198] Optionally, the angle formed between the first side surface 2321 and the first surface 2311 may be various. For example, Fig. 9In the embodiment, the first side surface 2321 is perpendicular to the first surface 2311, that is, the first side surface 2321 is parallel to the first direction X. This structure is beneficial to improving the welding quality between the first surface 2311 and the first side surface 2321. Of course, in other embodiments, the first side surface 2321 may also be arranged at an angle to the first direction X, that is, the first side surface 2321 is an inclined structure.

[0199] It should be noted that in Figure 7 and Figure 8 In the embodiment, since the additional portion 232 is an annular structure, the first side surface 2321 can be the inner circumferential surface of the additional portion 232, or the outer circumferential surface of the additional portion 232. Of course, in other embodiments, if the additional portion 232 is a strip structure or an arc structure, the first side surface 2321 is any side surface of the additional portion 232 in a direction perpendicular to the first direction X.

[0200] The first surface 2311 of the main body 231 in the first direction X and the first side surface 2321 of the additional part 232 in the second direction Y are welded to each other, so that the main body 231 and the additional part 232 are in a fillet welding connection relationship, so as to realize the welding connection between the main body 231 and the additional part 232. The current collecting component 23 with such a structure can achieve a greater penetration at a lower welding power, which is conducive to improving the welding effect between the additional part 232 and the main body 231, thereby effectively improving the connection stability between the additional part 232 and the main body 231, and can also effectively improve the connection stability between the additional part 232 and the main body 231. The weld mark formed by welding the additional part 232 and the main body part 231 is located on one side of the additional part 232 in the second direction Y, thereby reducing the interference effect of the weld mark formed by welding the additional part 232 and the main body part 231 on the mutual abutment and welding connection of the additional part 232 and the electrode lead-out part 211 in the first direction X, which is beneficial to improving the contact effect between the additional part 232 and the electrode lead-out part 211, thereby alleviating the risks of false welding or poor welding between the additional part 232 and the electrode lead-out part 211, and further effectively improving the welding quality between the additional part 232 and the electrode lead-out part 211.

[0201] In some embodiments, see Figure 8 and Fig. 9 As shown, along the second direction Y, the additional portion 232 has two first side surfaces 2321 that are oppositely disposed, and the two first side surfaces 2321 are both welded to the first surface 2311 .

[0202] The two first side surfaces 2321 are both welded to the first surface 2311 , that is, both sides of the additional portion 232 in the second direction Y are welded to the main body portion 231 .

[0203] By welding the two first side surfaces 2321 of the additional part 232 opposite to each other in the second direction Y to the first surface 2311 , it is helpful to improve the connection strength and connection stability between the additional part 232 and the main body 231 , and can improve the flow efficiency between the additional part 232 and the main body 231 .

[0204] In some embodiments, please see Figure 8 and Fig. 9 As shown, the additional portion 232 is an annular structure, and the two first side surfaces 2321 are respectively the inner circumference and the outer circumference of the additional portion 232 .

[0205] By setting the additional part 232 as an annular structure and welding the inner and outer surfaces of the additional part 232 to the first surface 2311 of the main body 231, it is beneficial to increase the welding area between the additional part 232 and the main body 231, so as to further improve the connection stability between the additional part 232 and the main body 231, and can improve the flow balance between the additional part 232 and the main body 231, which is beneficial to reduce the phenomenon of large local flow between the additional part 232 and the main body 231.

[0206] According to some embodiments of the present application, see Fig. 9 As shown, the two first side surfaces 2321 are welded to the first surface 2311 to form two first welding portions 233 , and the projections of the two first welding portions 233 in a plane perpendicular to the first direction X do not overlap.

[0207] The projections of the two first welding portions 233 in the plane perpendicular to the first direction X do not overlap, that is, the two first welding portions 233 are staggered in the first direction X, that is, the two first welding portions 233 are arranged at intervals in the plane perpendicular to the first direction X.

[0208] The projections of the two first welding parts 233 formed by welding the two first side faces 2321 of the additional part 232 and the first surface 2311 of the main body part 231 in the first direction X are set to be non-overlapping, so that the two first welding parts 233 are staggered structures in the first direction X, thereby reducing the phenomenon of molten pool penetration between the two first welding parts 233, which is beneficial to improving the welding quality between the additional part 232 and the main body part 231.

[0209] According to some embodiments of the present application, see Figure 8 and Fig. 9 As shown, the first surface 2311 is provided with a receiving groove 2312 for receiving the additional portion 232 . Along the first direction X, the additional portion 232 protrudes from the first surface 2311 , so that the first side surface 2321 extends out of the receiving groove 2312 .

[0210] Among them, along the first direction X, the additional part 232 protrudes from the first surface 2311 so that the first side surface 2321 extends to the outside of the receiving groove 2312, that is, the additional part 232 extends outside the receiving groove 2312 in the first direction X, so that part of the first side surface 2321 of the additional part 232 is located in the receiving groove 2312 in the first direction X, and the other part is located outside the receiving groove 2312 in the first direction X, that is, one of the two second surfaces 2322 connected to the first side surface 2321 is located in the receiving groove 2312, and the other second surface 2322 is located outside the receiving groove 2312 and is welded to the electrode lead-out portion 211.

[0211] By providing a receiving groove 2312 for receiving the additional part 232 on the first surface 2311 of the main body 231 facing the electrode lead-out portion 211, the additional part 232 protrudes from the first surface 2311 in the first direction X, so that the first side surface 2321 can extend from the inside of the receiving groove 2312 to the outside of the receiving groove 2312. The current collecting component 23 adopting such a structure can, on the one hand, reduce the occupied space of the current collecting component 23 in the first direction X, and can reduce the weight of the current collecting component 23, which is beneficial to optimize the weight of the battery cell 20 and the size in the first direction X, so as to improve the energy density of the battery cell 20. On the other hand, part of the first side surface 2321 is in the receiving groove 2312, and the other part is outside the receiving groove 2312, that is, the first surface 2311 has the first side surface 2321 on both sides in the first direction X, which is beneficial to improve the welding effect between the first surface 2311 and the first side surface 2321, so as to improve the welding quality between the additional part 232 and the main body 231.

[0212] In some embodiments, see Fig. 9 As shown, along the first direction X, the depth of the receiving groove 2312 is H1, and the thickness of the additional portion 232 is H2, satisfying that H2-H1≥0.2H2.

[0213] Among them, H2-H1≥0.2H2, that is, the difference between the thickness of the additional part 232 in the first direction X and the groove depth of the receiving groove 2312 in the first direction X is greater than or equal to 0.2 times the thickness of the additional part 232 in the first direction X, that is, the size of the portion of the additional part 232 protruding from the first surface 2311 in the first direction X is greater than or equal to 0.2 times the thickness of the additional part 232 in the first direction X. Similarly, that is to say, the distance between the second surface 2322 located outside the receiving groove 2312 and the first surface 2311 in the first direction X is greater than or equal to 0.2 times the thickness of the additional part 232 in the first direction X.

[0214] Illustratively, H2-H1 may be 0.2 times, 0.22 times, 0.25 times, 0.3 times, 0.35 times, 0.4 times, 0.5 times, 0.6 times, 0.7 times, 0.8 times or 1 times of H2.

[0215] By setting the difference between the thickness of the additional part 232 in the first direction X and the groove depth of the accommodating groove 2312 in the first direction X to be greater than or equal to 0.2 times the thickness of the additional part 232 in the first direction X, that is, the size of the portion of the additional part 232 protruding from the first surface 2311 in the first direction X is greater than or equal to 0.2 times the thickness of the additional part 232 in the first direction X, it is helpful to alleviate the phenomenon that the weld mark formed by the welding of the first surface 2311 and the first side surface 2321 exceeds the side of the additional part 232 facing the electrode lead-out portion 211 in the first direction X, thereby effectively reducing the risk of poor contact or loss of contact between the additional part 232 and the electrode lead-out portion 211 due to the interference of the weld mark formed by the welding of the additional part 232 and the main body 231, thereby alleviating the phenomenon of cold welding or poor welding between the additional part 232 and the electrode lead-out portion 211, and further effectively improving the welding quality between the additional part 232 and the electrode lead-out portion 211.

[0216] In some embodiments, please see Fig. 9 As shown, the first side surface 2321 abuts against the groove side surface of the accommodating groove 2312 .

[0217] Before the additional part 232 and the main body part 231 are welded to each other, the first surface 2311 and the side surface of the accommodating groove 2312 are connected to each other, and the first side surface 2321 is abutted against the bottom surface of the accommodating groove 2312 to enable the edge of the first side surface 2321 and the first surface 2311 to abut against each other.

[0218] The receiving groove 2312 is disposed on the first surface 2311 , and the first side surface 2321 and the groove side surface of the receiving groove 2312 abut against each other, thereby reducing the gap between the first side surface 2321 and the first surface 2311 , which is beneficial to improving the welding quality between the first side surface 2321 and the first surface 2311 .

[0219] According to some embodiments of the present application, see Figure 5 and Figure 6 As shown, the additional portion 232 is welded to the main body portion 231 to form at least one first welding portion 233, and the main body portion 231 is welded to the tab 222 to form at least one second welding portion 24. The projections of at least one first welding portion 233 and at least one second welding portion 24 in a plane perpendicular to the first direction X do not overlap.

[0220] Among them, the projections of at least one first welding portion 233 and at least one second welding portion 24 in a plane perpendicular to the first direction X do not overlap, that is, the projection of any first welding portion 233 in the first direction X and the projection of any second welding portion 24 in the first direction X do not intersect with each other, that is, the projection of any first welding portion 233 in a plane perpendicular to the first direction X and the projection of any second welding portion 24 in a plane perpendicular to the first direction X are arranged at intervals.

[0221] Optionally, the main body 231 plays the role of welding with the pole lug 222 to form an electrical connection. The second welding portion 24 formed by the welding connection between the main body 231 and the pole lug 222 can be located on the outside of the additional portion 232 or on the inside of the additional portion 232. Similarly, the second welding portion 24 formed by the welding connection between the main body 231 and the pole lug 222 can be one or more. When there are multiple second welding portions 24, the multiple second welding portions 24 can be all located on the inside or outside of the additional portion 232, or the second welding portions 24 can be provided on both the inside and the outside of the additional portion 232.

[0222] The first welding portion 233 formed by welding the additional portion 232 to the main body portion 231 and the second welding portion 24 formed by welding the main body portion 231 to the pole tab 222 are arranged so that their projections in the first direction X do not overlap with each other, so that the first welding portion 233 and the second welding portion 24 are staggered structures in the first direction X, thereby reducing the occurrence of a molten pool between the first welding portion 233 and the second welding portion 24, which is beneficial to improving the welding quality between the additional portion 232 and the main body portion 231 and between the main body portion 231 and the pole tab 222.

[0223] In some embodiments, see Figure 5 and Figure 6 As shown, the additional portion 232 surrounds the outer side of the second welding portion 24. That is, the additional portion 232 is an annular structure, and the additional portion 232 surrounds the outer side of the second welding portion 24. Of course, in other embodiments, the second welding portion 24 can also be located outside the additional portion 232.

[0224] By setting the additional part 232 as a structure surrounding the outer side of the second welding part 24 formed by welding the main body part 231 and the pole tab 222, that is, the second welding part 24 formed by welding the main body part 231 and the pole tab 222 is located on the inner circumference of the additional part 232, it is helpful to shorten the current path between the pole tab 222 and the current collecting component 23.

[0225] The structure of the battery cell 20 is not limited to this. In other embodiments, the battery cell 20 can also be other structures. For example, at least one second welding portion 24 includes two second welding portions 24, the additional portion 232 surrounds the outside of one second welding portion 24, and the other second welding portion 24 surrounds the outside of the additional portion 232.

[0226] Two second welding portions 24 are formed by welding the main body 231 and the pole tab 222 , and one of the two second welding portions 24 is located on the inner peripheral side of the additional portion 232 , and the other second welding portion 24 is located on the outer peripheral side of the additional portion 232 , which is beneficial to further improve the flow efficiency between the pole tab 222 and the current collecting component 23 .

[0227] According to some embodiments of the present application, see Figure 5 and Figure 6 As shown, the additional portion 232 is welded to the main body portion 231 to form at least one first welding portion 233, and the additional portion 232 is welded to the electrode lead portion 211 to form at least one third welding portion 25. The projections of at least one first welding portion 233 and at least one third welding portion 25 in a plane perpendicular to the first direction X do not overlap.

[0228] Among them, the projections of at least one first welding portion 233 and at least one third welding portion 25 in a plane perpendicular to the first direction X do not overlap, that is, the projection of any first welding portion 233 in the first direction X and the projection of any third welding portion 25 in the first direction X do not intersect with each other, that is, the projection of any first welding portion 233 in a plane perpendicular to the first direction X and the projection of any third welding portion 25 in a plane perpendicular to the first direction X are arranged at intervals.

[0229] Illustratively, there is one third welding portion 25 .

[0230] It should be noted that see Figure 6 and Fig. 9 As shown, in the embodiment in which the first side surface 2321 of the additional portion 232 is connected to the first surface 2311 of the main body portion 231 by a corner weld, the first welding portion 233 can be located on the inner side of the second welding portion 24, or on the outer side of the second welding portion 24. In the embodiment in which the first side surface 2321 of the additional portion 232 is connected to the first surface 2311 of the main body portion 231 by a corner weld and two first welding portions 233 are formed, the two first welding portions 233 are respectively located on both sides of the second welding portion 24 in the second direction Y, that is, in the second direction Y, the second welding portion 24 is located between the two first welding portions 233, and are both spaced apart from the two first welding portions 233.

[0231] The first welding portion 233 formed by welding the additional portion 232 to the main body portion 231 and the third welding portion 25 formed by welding the additional portion 232 to the electrode lead-out portion 211 are arranged so that their projections in the first direction X do not overlap with each other, so that the first welding portion 233 and the third welding portion 25 are staggered structures in the first direction X, thereby reducing the occurrence of a molten pool between the first welding portion 233 and the third welding portion 25, which is beneficial to improving the welding quality between the additional portion 232 and the main body portion 231 and between the additional portion 232 and the electrode lead-out portion 211.

[0232] According to some embodiments of the present application, see Figure 5 and Figure 6 As shown, the third welding portion 25 penetrates the electrode lead-out portion 211 along the first direction X. That is, the third welding portion 25 passes through both sides of the electrode lead-out portion 211 in the first direction X.

[0233] By setting the third welding portion 25 to a structure that penetrates the electrode lead-out portion 211 in the first direction X, on the one hand, the connection reliability between the additional portion 232 and the electrode lead-out portion 211 can be improved, and on the other hand, it is convenient to weld the additional portion 232 and the electrode lead-out portion 211 from the outside of the electrode lead-out portion 211, which helps to reduce the difficulty of welding.

[0234] In some embodiments, the third weld 25 is configured to be formed by irradiating a laser from a side of the electrode lead-out portion 211 away from the electrode assembly 22 to melt at least a portion of the electrode lead-out portion 211 and the additional portion 232. That is, the third weld 25 is formed by laser welding the electrode lead-out portion 211 and the additional portion 232, and the laser is irradiated from a side of the electrode lead-out portion 211 away from the additional portion 232.

[0235] The third welding portion 25 is formed by laser welding on the outer side of the electrode lead-out portion 211 , which helps to reduce the difficulty of welding between the additional portion 232 and the electrode lead-out portion 211 , thereby improving the assembly efficiency of the battery cell 20 .

[0236] In some embodiments, see Figure 6 As shown, the third welding portion 25 does not penetrate the additional portion 232 along the first direction X. That is, the third welding portion 25 does not penetrate the side of the additional portion 232 away from the electrode lead-out portion 211 in the first direction X.

[0237] By setting the third welding portion 25 to a structure that does not penetrate the additional portion 232 along the first direction X, on the one hand, the welding power required for welding the additional portion 232 and the electrode lead-out portion 211 can be reduced, which is beneficial to reducing the welding difficulty. On the other hand, it can alleviate the adverse effects of the third welding portion 25 penetrating the additional portion on the main body 231 and the pole ear 222.

[0238] According to some embodiments of the present application, referring to Figure 5 and Figure 6 , and please refer to Fig.12 , Fig.12 Schematic diagram of welding of the current collecting member 23, the pole tab 222 and the electrode lead-out portion 211 provided in some embodiments of the present application. The additional portion 232 is welded to the main body portion 231 to form at least one first welding portion 233, the main body portion 231 is welded to the pole tab 222 to form at least one second welding portion 24, and the additional portion 232 is welded to the electrode lead-out portion 211 to form at least one third welding portion 25.

[0239] Among them, the projection area of ​​at least one first welding portion 233 in the plane perpendicular to the first direction X is S1, the projection area of ​​at least one second welding portion 24 in the plane perpendicular to the first direction X is S2, and the projection area of ​​at least one third welding portion 25 in the plane perpendicular to the first direction X is S3, satisfying 0.8≤S1 / S2≤1.2; and / or, 0.8≤S1 / S3≤1.2; and / or, 0.8≤S2 / S3≤1.2. That is, the sum of the projection areas of all first welding portions 233 in the plane perpendicular to the first direction X is S1, the sum of the projection areas of all second welding portions 24 in the plane perpendicular to the first direction X is S2, and the sum of the projection areas of all third welding portions 25 in the plane perpendicular to the first direction X is S3.

[0240] Preferably, the projection area of ​​at least one first welding portion 233 in a plane perpendicular to the first direction X, the projection area of ​​at least one second welding portion 24 in a plane perpendicular to the first direction X, and the projection area of ​​at least one third welding portion 25 in a plane perpendicular to the first direction X are all equal.

[0241] By setting the projection area of ​​at least one first welding portion 233 in a plane perpendicular to the first direction X, the projection area of ​​at least one second welding portion 24 in a plane perpendicular to the first direction X, and the projection area of ​​at least one third welding portion 25 in a plane perpendicular to the first direction X to be in a ratio of 0.8 to 1.2, so as to achieve that the projection area of ​​at least one first welding portion 233 in a plane perpendicular to the first direction X, the projection area of ​​at least one second welding portion 24 in a plane perpendicular to the first direction X, and the projection area of ​​at least one third welding portion 25 in a plane perpendicular to the first direction X are close to each other, so that on the one hand, the phenomenon that the overall flow capacity is bottlenecked or restricted due to the small projection area of ​​one of the first welding portion 233, the second welding portion 24, and the third welding portion 25 in the first direction X is too small can be alleviated, and on the other hand, the phenomenon that the local flow capacity is excessive due to the large projection area of ​​one of the first welding portion 233, the second welding portion 24, and the third welding portion 25 in the first direction X is alleviated, so as to reduce unnecessary waste and reduce the production cost of the battery cell 20.

[0242] According to some embodiments of the present application, see Fig.12 As shown, the additional portion 232 is welded to the main body 231 to form at least one first welding portion 233, and the first welding portion 233 is an annular structure. And / or, the additional portion 232 is an annular structure, and the additional portion 232 is welded to the electrode lead-out portion 211 to form at least one second welding portion 24, and the second welding portion 24 is an annular structure. And / or, the main body 231 is welded to the pole ear 222 to form at least one third welding portion 25, and the third welding portion 25 is an annular structure.

[0243] Among them, the first welding portion 233 is an annular structure, that is, the first welding portion 233 is a ring connected end to end in its extension direction. Similarly, the second welding portion 24 is an annular structure, that is, the second welding portion 24 is a ring connected end to end in its extension direction. The third welding portion 25 is an annular structure, that is, the third welding portion 25 is a ring connected end to end in its extension direction.

[0244] For example, in Fig.12 In the embodiment, the first welding portion 233, the second welding portion 24 and the third welding portion 25 are all annular structures. Of course, in other embodiments, the first welding portion 233, the second welding portion 24 and the third welding portion 25 may also be a strip structure, an arc structure or an annular discontinuous structure. Similarly, the first welding portion 233, the second welding portion 24 and the third welding portion 25 may also be a radial structure composed of a plurality of weld marks, for example, a plurality of weld marks are arranged at intervals along the circumference of the current collecting member 23, and each weld mark extends along the radial direction of the current collecting member 23.

[0245] By setting the first welding portion 233 formed by mutually welding the additional portion 232 and the main body portion 231 to a ring structure, it is beneficial to improve the connection stability between the additional portion 232 and the main body portion 231, and it is beneficial to improve the flow area and flow balance between the additional portion 232 and the main body portion 231, so as to improve the flow effect between the additional portion 232 and the main body portion 231. Similarly, by setting the second welding portion 24 formed by mutually welding the additional portion 232 and the electrode lead-out portion 211 to a ring structure, it is beneficial to improve the connection stability between the additional portion 232 and the electrode lead-out portion 211, and it is beneficial to improve the flow area and flow balance between the additional portion 232 and the electrode lead-out portion 211, so as to improve the flow effect between the additional portion 232 and the electrode lead-out portion 211. Similarly, by setting the third welding portion 25 formed by welding the main body 231 and the pole lug 222 to each other as an annular structure, it is beneficial to improve the connection stability between the main body 231 and the pole lug 222, and to improve the flow area and flow balance between the main body 231 and the pole lug 222, so as to improve the flow effect between the main body 231 and the pole lug 222.

[0246] According to some embodiments of the present application, see Figure 4 , Figure 5 and Figure 6 As shown, the tab 222 is disposed at one end of the main body 221 facing the body portion 231 .

[0247] Among them, the pole ear 222 is arranged at one end of the main body 221 facing the main body part 231, that is, the pole ear 222 is connected to one end of the main body 221 close to the electrode lead-out part 211 in the first direction X, that is, the pole ear 222 is formed at one end of the electrode assembly 22 close to the electrode lead-out part 211 in the first direction X, so that the pole ear 222 is located between the main body 221 and the main body part 231 in the first direction X.

[0248] By arranging the pole ear 222 to be located on the side of the main body 221 facing the main body 231 of the current collecting component 23 in the first direction X, the pole ear 222 and the main body 231 are arranged facing each other in the first direction X, thereby facilitating the welding of the main body 231 of the current collecting component 23 and the pole ear 222 of the electrode assembly 22, which helps to reduce the difficulty of assembling the current collecting component 23 and the pole ear 222.

[0249] In some embodiments, see Figure 4 and Figure 5 As shown, the main body 221 is cylindrical.

[0250] The central axis of the main body 221 extends along the first direction X.

[0251] By setting the main body 221 of the electrode assembly 22 to a cylindrical structure, it is convenient to form a cylindrical battery cell 20 in subsequent processing, so that the battery cell 20 has the advantages of high capacity, long cycle life, and a wide range of ambient temperature.

[0252] According to some embodiments of the present application, see Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the housing assembly 21 may include a housing 212 , the electrode assembly 22 is accommodated in the housing 212 , and the housing 212 has a wall portion 2121 , and the wall portion 2121 is the electrode lead-out portion 211 .

[0253] The wall portion 2121 is the electrode lead-out portion 211 , that is, the additional portion 232 of the current collecting member 23 is welded to a wall of the housing 212 to achieve input or output of electrical energy of the battery cell 20 .

[0254] The shell assembly 21 is provided with a shell 212. By using the wall 2121 of the shell 212 as the electrode lead-out portion 211, the pole ear 222 is connected to the wall 2121 of the shell 212 through the current collecting component 23, so that the input or output of electrical energy of the battery cell 20 can be realized. The structure is simple and easy to assemble.

[0255] According to some embodiments of the present application, see Figure 5 and Figure 6 As shown, a convex portion 2121 a is formed on one side of the wall portion 2121 facing the electrode assembly 22 , and the convex portion 2121 a is welded to the additional portion 232 .

[0256] A convex portion 2121 a is formed on the side of the wall portion 2121 facing the electrode assembly 22 , that is, in the first direction X, a convex portion 2121 is formed on the side of the wall portion 2121 facing the electrode assembly 22 and protrudes toward the electrode assembly 22 .

[0257] It should be noted that, in an embodiment in which the additional portion 232 is welded to the main body portion 231 to form a first welding portion 233, and the additional portion 232 is welded to the electrode lead-out portion 211 to form a second welding portion 24, the protrusion 2121a is welded to the additional portion 232, that is, the protrusion 2121a of the wall portion 2121 is the electrode lead-out portion 211, and the protrusion 2121a is welded to the additional portion 232 to form a second welding portion 24.

[0258] By forming a protrusion 2121a on the side of the wall portion 2121 facing the electrode assembly 22, and welding the protrusion 2121a to the additional portion 232 of the current collecting component 23, a welding connection between the additional portion 232 and the wall portion 2121 is achieved. The battery cell 20 with such a structure facilitates the welding connection between the wall portion 2121 and the additional portion 232 of the current collecting component 23 after the protrusion 2121a abuts against each other, which helps to reduce the difficulty of welding between the additional portion 232 and the wall portion 2121.

[0259] In some embodiments, see Figure 4 , Figure 5 and Figure 6 As shown, a groove 2121 b is formed on the side of the wall portion 2121 away from the electrode assembly 22 and at a position corresponding to the protrusion 2121 a.

[0260] Exemplarily, the wall portion 2121 is formed by stamping, so that a convex portion 2121a and a concave portion 2121b are respectively formed on both sides of the wall portion 2121 along the first direction X. Of course, in other embodiments, the wall portion 2121 may also be formed by casting or other processes.

[0261] A groove 2121b is formed on the side of the wall portion 2121 away from the electrode assembly 22 and corresponding to the position of the convex portion 2121a, so that the wall portion 2121 has a concave-convex structure formed by stamping, thereby forming the convex portion 2121a and the groove 2121b on both sides of the wall portion 2121 respectively, which is beneficial to reducing the processing difficulty and improving the processing efficiency. The wall portion 2121 with such a structure can effectively improve the structural strength of the wall portion 2121 to alleviate the deformation phenomenon when the wall portion 2121 and the additional portion 232 are welded to each other, which is beneficial to improving the production quality of the battery cell 20.

[0262] According to some embodiments of this application, please refer to Fig.13 , Fig.14 and Fig.15 , Fig.13 The schematic diagram of the structure of the battery cell 20 provided in some other embodiments of the present application is as follows: Fig.14 The structure explosion diagram of the battery cell 20 provided in some other embodiments of the present application is as follows: Fig.15 Partial cross-sectional views of battery cells 20 provided in some other embodiments of the present application. The housing assembly 21 may further include a housing 212, and the electrode assembly 22 is accommodated in the housing 212. The housing 212 has a wall portion 2121, and the electrode lead portion 211 is insulated and mounted on the wall portion 2121.

[0263] Among them, the outer shell 212 has a wall portion 2121, and the electrode lead portion 211 is insulated and installed on the wall portion 2121. That is, the electrode lead portion 211 is a component (electrode terminal) insulated and installed on a wall of the outer shell 212, and no electrical connection is formed between the electrode lead portion 211 and the wall portion 2121 of the outer shell 212, so that the welding connection between the electrode lead portion 211 and the additional portion 232 of the current collecting component 23 can realize the input or output of electrical energy of the battery cell 20.

[0264] The shell assembly 21 is also provided with a shell 212. By insulating the electrode lead-out portion 211 and installing it on the wall portion 2121 of the shell 212, the input or output of electrical energy of the battery cell 20 can be achieved through the electrode lead-out portion 211. The battery cell 20 adopting this structure can reduce the risk of short circuit between the electrode lead-out portion 211 and the shell 212.

[0265] According to some embodiments of the present application, see Figure 4 and Figure 5 as well as Fig.14 and Fig.15 As shown, the housing 212 may include a shell 2122 and an end cap 2123 . The shell 2122 has an accommodation cavity with an opening 2122 a formed inside, and the electrode assembly 22 is accommodated in the accommodation cavity. The end cap 2123 closes the opening 2122 a , and the end cap 2123 is a wall portion 2121 .

[0266] The end cover 2123 is a wall portion 2121 , that is, the end cover 2123 is welded to the additional portion 232 of the current collecting member 23 or the electrode lead portion 211 is insulated and installed on the end cover 2123 , so that the current collecting member 23 is located between the main body 221 and the end cover 2123 in the first direction X.

[0267] The wall portion 2121 of the outer shell 212 is an end cover 2123 of the outer shell 212 for closing the opening 2122a of the shell 2122. The battery cell 20 adopting this structure is convenient for assembling the current collecting component 23, which is beneficial to reducing the difficulty of connecting the current collecting component 23 with the electrode lead-out portion 211 and the current collecting component 23 with the pole ear 222, thereby improving the production efficiency of the battery cell 20.

[0268] It should be noted that the structure of the battery cell 20 is not limited thereto. In some embodiments, the battery cell 20 may also be other structures. For example, the housing 212 may include a shell 2122 and an end cap 2123. The shell 2122 includes an integrally formed side wall and a wall portion 2121. The side wall is arranged around the wall portion 2121. One end of the side wall is connected to the wall portion 2121. The other end of the side wall forms an opening 2122a opposite to the wall portion 2121. The side wall and the wall portion 2121 jointly define a receiving cavity for accommodating the electrode assembly 22. The end cap 2123 closes the opening 2122a. In other words, the wall portion 2121 is the bottom wall of the shell 2122 arranged opposite to the end cap 2123 in the first direction X, that is, the bottom wall of the shell 2122 is welded to the additional portion 232 of the current collecting member 23 or the electrode lead portion 211 is insulated and installed on the bottom wall of the shell 2122.

[0269] The shell 2122 includes an integrally formed side wall and wall portion 2121 , that is, the shell 2122 is made by an integral forming process, such as stamping, casting or extrusion, that is, the side wall and wall portion 2121 of the shell 2122 are an integral structure.

[0270] By setting the wall portion 2121 as a wall arranged opposite to the shell 2122 and the end cover 2123, the battery cell 20 adopting this structure can keep the components such as the current collecting member 23 away from the end cover 2123, and make there no direct connection relationship between the wall portion 2121 and the end cover 2123, thereby alleviating the phenomenon that the force generated by the pulling or twisting of the wall portion 2121 by the current collecting member 23 and other components acts on the end cover 2123, thereby reducing the risk of connection failure between the end cover 2123 and the shell 2122, which is beneficial to further reduce the risk of leakage of the battery cell 20 during use.

[0271] According to some embodiments of the present application, the present application further provides a battery 100, and the battery 100 includes a battery cell 20 of any of the above schemes.

[0272] In some embodiments, see Figure 2 As shown, the battery 100 may further include a box body 10 , and the box body 10 is used to accommodate the battery cells 20 .

[0273] The box body 10 is used to provide an assembly space for the battery cell 20, and the box body 10 can adopt a variety of structures. Exemplarily, the box body 10 can 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 cell 20.

[0274] Optionally, the second box body 12 can be a hollow structure with one end open, and the first box body 11 can be a plate-like structure. The first box body 11 covers the open side of the second box body 12, so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 can also be hollow structures both with one side open, and the open side of the first box body 11 covers the open side of the second box body 12.

[0275] 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, etc. Figure 2 In the embodiment, the box body 10 is in the shape of a rectangular parallelepiped.

[0276] Optionally, the battery cell 20 contained in the box body 10 may be one or more. Figure 2 In the embodiment, the battery 100 may include a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection means that the plurality of battery cells 20 are both connected in series and in parallel. The plurality of battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the whole formed by the plurality of battery cells 20 is accommodated in the box 10; of course, the battery 100 may also be a battery module formed by first connecting a plurality of battery cells 20 in series, in parallel, or in a hybrid connection, and then the plurality of battery modules are connected in series, in parallel, or in a hybrid connection to form a whole, and then accommodated in the box 10.

[0277] 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 plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0278] It should be noted that, in some embodiments, the battery 100 may not be provided with a box 10, and the battery 100 includes a plurality of battery cells 20, and the battery 100 composed of a plurality of battery cells 20 may be directly assembled on an electrical device to provide electrical energy to the electrical device through the plurality of battery cells 20. In other words, the box 10 may be used as a part of the electrical device. Taking the vehicle 1000 as an example of the electrical device, the box 10 may be used as a part of the chassis structure of the vehicle 1000, for example, a part of the box 10 may become at least a part of the floor of the vehicle 1000, or a part of the box 10 may become at least a part of the crossbeam and longitudinal beam of the vehicle 1000.

[0279] According to some embodiments of the present application, the present application further provides an electrical device, which includes the battery 100 of any of the above solutions, and the battery 100 is used to provide electrical energy to the electrical device.

[0280] The power-consuming device may be any of the aforementioned devices or systems using the battery 100 .

[0281] According to some embodiments of the present application, see Figures 3 to 9 as well as Fig.12 As shown, the present application provides a battery cell 20, which includes a housing assembly 21, an electrode assembly 22 and a current collecting member 23. The housing assembly 21 has an electrode lead-out portion 211 for inputting or outputting electric energy, and the housing assembly 21 may include a housing 212, and the housing 212 has a wall portion 2121, which is the electrode lead-out portion 211. The housing 212 includes a shell 2122 and an end cover 2123, and a receiving cavity with an opening 2122a is formed inside the shell 2122, and the end cover 2123 closes the opening 2122a, and the end cover 2123 is a wall portion 2121. Along the first direction X, a convex portion 2121a is formed on one side of the wall portion 2121 facing the inside of the housing 212, and a groove 2121b is formed on one side of the wall portion 2121 facing away from the inside of the housing 212 and corresponding to the position of the convex portion 2121a. The electrode assembly 22 is accommodated in the accommodating cavity of the shell 2122. The electrode assembly 22 includes a main body 221 and a tab 222. The main body 221 is cylindrical, and the central axis of the main body 221 extends along the first direction X. The tab 222 is connected to one end of the main body 221 facing the electrode lead-out portion 211 in the first direction X. The tab 222 and the electrode lead-out portion 211 are made of different materials. The current collecting member 23 is disposed in the shell 212 of the shell assembly 21. The current collecting member 23 includes a main body 231 and an additional portion 232 connected to each other. The material of the main body 231 is the same as that of the tab 222, and the material of the additional portion 232 is the same as that of the electrode lead-out portion 211. The main body 231 is welded to the tab 222, and the additional portion 232 is welded to the convex portion 2121a. Along the first direction X, the current collecting member 23 is disposed between the electrode assembly 22 and the electrode lead-out portion 211, the body portion 231 has a first surface 2311 facing the electrode lead-out portion 211, the first surface 2311 is provided with a receiving groove 2312, a portion of the additional portion 232 is received in the receiving groove 2312, the additional portion 232 protrudes from the first surface 2311 along the first direction X, and the portion of the additional portion 232 protruding from the first surface 2311 is welded to the electrode lead-out portion 211. The additional portion 232 is an annular structure, and correspondingly, the receiving groove 2312 is an annular groove extending along the extension direction of the additional portion 232. Along the first direction X, the groove depth of the receiving groove 2312 is H1, and the thickness of the additional portion 232 is H2, satisfying that H2-H1≥0.2H2.

[0282] Along the second direction Y, the additional portion 232 has two opposite first side surfaces 2321, the two first side surfaces 2321 are respectively the inner circumference and the outer circumference of the additional portion 232, the two first side surfaces 2321 are respectively in contact with the two opposite groove sides of the accommodating groove 2312, and the two first side surfaces 2321 are both welded to the first surface 2311, and the second direction Y is perpendicular to the first direction X. The two first side surfaces 2321 are both welded to the first surface 2311 to form two first welding portions 233, and the projections of the two first welding portions 233 in a plane perpendicular to the first direction X do not overlap. The main body 231 is welded to the tab 222 to form a second welding portion 24, the additional portion 232 surrounds the outer side of the second welding portion 24, and the projections of the first welding portion 233 and the second welding portion 24 in a plane perpendicular to the first direction X do not overlap. The additional portion 232 is welded to the convex portion 2121a to form a third welding portion 25, and the third welding portion 25 penetrates the electrode lead-out portion 211 along the first direction X. The projections of the first welding portion 233 and the third welding portion 25 in a plane perpendicular to the first direction X do not overlap. The first welding portion 233, the second welding portion 24, and the third welding portion 25 are all annular structures, and the two first welding portions 233 are surrounded by the outside of the second welding portion 24, the third welding portion 25 is surrounded by the outside of one first welding portion 233, and the other first welding portion 233 is surrounded by the outside of the third welding portion 25.

[0283] Among them, the projection area of ​​the first welding portion 233 in the plane perpendicular to the first direction X is S1, the projection area of ​​the second welding portion 24 in the plane perpendicular to the first direction X is S2, and the projection area of ​​the third welding portion 25 in the plane perpendicular to the first direction X is S3, satisfying 0.8≤S1 / S2≤1.2, 0.8≤S1 / S3≤1.2, 0.8≤S2 / S3≤1.2.

[0284] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0285] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing assembly including an electrode lead-out portion for inputting or outputting electrical energy; An electrode assembly is contained in the housing assembly, the electrode assembly comprises a main body and a tab, the tab is arranged on the main body, and the tab is made of a different material from the electrode lead-out portion; as well as A current collecting component is arranged in the shell assembly, and the current collecting component includes a main body portion made of the same material as the pole tab and an additional portion made of the same material as the electrode lead portion, the main body portion is connected to the additional portion, the main body portion is welded to the pole tab, and the additional portion is welded to the electrode lead portion.

2. The battery cell according to claim 1, characterized in that: Along the first direction, at least a portion of the current collecting member is disposed between the electrode assembly and the electrode lead-out portion; Wherein, along the first direction, the additional portion is connected to a side of the main body portion facing away from the electrode assembly.

3. The battery cell according to claim 2, characterized in that: Along the first direction, the main body has a first surface facing the electrode lead-out portion, the first surface is provided with a receiving groove, and at least a part of the additional portion is received in the receiving groove.

4. The battery cell according to claim 3, characterized in that: Along the first direction, the additional portion protrudes from the first surface, and a portion of the additional portion protruding from the first surface is welded to the electrode lead-out portion.

5. The battery cell according to claim 3, characterized in that: Along the first direction, the additional portion has a second surface facing the electrode lead-out portion, and the second surface is flush with the first surface.

6. The battery cell according to claim 3, characterized in that: The additional portion is an annular structure.

7. The battery cell according to claim 6, characterized in that: The accommodating groove is an annular groove extending along the extending direction of the additional portion.

8. The battery cell according to claim 2, characterized in that: The current collecting component includes a plurality of the additional parts, each of which is connected to the main body. Along the first direction, projections of the plurality of additional parts in a plane perpendicular to the first direction do not overlap with each other.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The main body portion is connected to the additional portion by welding.

10. The battery cell according to claim 9, characterized in that: Along the first direction, the current collecting member is disposed between the electrode assembly and the electrode lead-out portion; Wherein, along the first direction, the main body has a first surface facing the electrode lead-out portion, along the second direction, the additional portion has a first side surface, the first side surface is welded to the first surface, and the second direction is perpendicular to the first direction.

11. The battery cell according to claim 10, characterized in that: Along the second direction, the additional portion has two first side surfaces that are oppositely arranged, and the two first side surfaces are both welded to the first surface.

12. The battery cell according to claim 11, characterized in that: The additional part is an annular structure, and the two first side surfaces are respectively the inner circumferential surface and the outer circumferential surface of the additional part.

13. The battery cell according to claim 11, characterized in that: The two first side surfaces are both welded to the first surface to form two first welding portions; The projections of the two first welding portions in a plane perpendicular to the first direction do not overlap.

14. The battery cell according to claim 10, characterized in that: The first surface is provided with a receiving groove for receiving the additional part. Along the first direction, the additional part protrudes from the first surface so that the first side surface extends out of the receiving groove.

15. The battery cell according to claim 14, characterized in that: Along the first direction, the depth of the accommodating groove is H1, and the thickness of the additional portion is H2, satisfying H2-H1≥0.2H2.

16. The battery cell according to claim 14, characterized in that: The first side surface abuts against a groove side surface of the accommodating groove.

17. The battery cell according to claim 2, characterized in that: The additional portion is welded to the main body portion to form at least one first welding portion, and the main body portion is welded to the tab to form at least one second welding portion; The projections of the at least one first welding portion and the at least one second welding portion in a plane perpendicular to the first direction do not overlap.

18. The battery cell according to claim 17, characterized in that: The additional portion surrounds the outer side of the second welding portion.

19. The battery cell according to claim 17, characterized in that: The at least one second welding portion includes two second welding portions, the additional portion surrounds an outer side of one of the second welding portions, and the other second welding portion surrounds an outer side of the additional portion.

20. The battery cell according to claim 2, characterized in that: The additional portion is welded to the main body portion to form at least one first welding portion, and the additional portion is welded to the electrode lead-out portion to form at least one third welding portion; The projections of the at least one first welding portion and the at least one third welding portion in a plane perpendicular to the first direction do not overlap.

21. The battery cell according to claim 20, characterized in that: The third welding portion penetrates the electrode lead-out portion along the first direction.

22. The battery cell according to claim 21, characterized in that: The third welding portion is configured to be formed by melting at least a portion of the electrode lead-out portion and the additional portion by irradiating a laser from a side of the electrode lead-out portion facing away from the electrode assembly.

23. The battery cell according to claim 20, characterized in that: The third welding portion does not penetrate the additional portion along the first direction.

24. The battery cell according to claim 2, characterized in that: The additional part is welded to the main body to form at least one first welding part, the main body is welded to the tab to form at least one second welding part, and the additional part is welded to the electrode lead-out part to form at least one third welding part; Among them, the projection area of ​​the at least one first welding portion in the plane perpendicular to the first direction is S1, the projection area of ​​the at least one second welding portion in the plane perpendicular to the first direction is S2, and the projection area of ​​the at least one third welding portion in the plane perpendicular to the first direction is S3, satisfying, 0.8≤S1 / S2≤1.2; and / or, 0.8≤S1 / S3≤1.2; and / or, 0.8≤S2 / S3≤1.

2.

25. The battery cell according to claim 2, characterized in that: The additional portion is welded to the main body portion to form at least one first welding portion, wherein the first welding portion is an annular structure; and / or The main body is welded to the tab to form at least one third welding portion, and the third welding portion is an annular structure.

26. The battery cell according to claim 1, characterized in that: The pole ear is arranged at one end of the main body facing the main body.

27. The battery cell according to claim 1, characterized in that: The main body is cylindrical.

28. The battery cell according to claim 1, characterized in that: The housing assembly comprises a housing, and the electrode assembly is accommodated in the housing; Wherein, the shell has a wall portion, and the wall portion is the electrode lead-out portion.

29. The battery cell according to claim 28, characterized in that: A convex portion is formed on a side of the wall portion facing the electrode assembly, and the convex portion is welded to the additional portion.

30. The battery cell according to claim 29, characterized in that A groove is formed on a side of the wall portion away from the electrode assembly and corresponding to a position of the protrusion.

31. The battery cell according to claim 1, characterized in that The housing assembly further comprises a housing, and the electrode assembly is accommodated in the housing; The housing has a wall portion, and the electrode lead-out portion is insulated and mounted on the wall portion.

32. The battery cell according to any one of claims 28 to 31, characterized in that: The housing comprises: A housing having an opening formed therein, wherein the electrode assembly is accommodated in the housing; an end cap for closing the opening; Wherein, the end cover is the wall portion.

33. The battery cell according to any one of claims 28 to 31, characterized in that: The housing comprises: A shell, comprising an integrally formed side wall and the wall portion, wherein the side wall is disposed around the wall portion, one end of the side wall is connected to the wall portion, and the other end of the side wall forms an opening opposite to the wall portion, and the side wall and the wall portion jointly define a housing cavity for housing the electrode assembly; An end cap closes the opening.

34. A battery, characterized in that: Comprising a battery cell as described in any one of claims 1-33.

35. An electrical device, characterized in that: Comprising a battery as claimed in claim 34.

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