Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device, and belongs to the technical field of batteries. The battery monomer comprises a shell, an electrode assembly and an end cover, an opening is formed in at least one end of the housing in the first direction. The electrode assembly is housed within the case. The end cover seals the opening, the end cover comprises a cover body and a turnup part, the turnup part is connected to the outer edge of the cover body and is bent towards one side, in the first direction, of the cover body, the turnup part is arranged around the cover body, at least part of the turnup part is inserted into the shell in the first direction, and the turnup part abuts against the inner circumferential surface of the shell. The end cover is provided with a first groove, and the first groove is configured to reduce the extrusion force applied to the inner circumferential surface of the shell by the flanging part. The end cover is more easily deformed when the flanging part and the inner circumferential surface of the shell are mutually abutted and assembled, so that the extrusion force applied by the flanging part to the inner circumferential surface of the shell can be reduced, the phenomenon of deformation and external expansion of the shell is relieved, and the production quality of the battery monomer is favorably improved.

Description

Technical Field

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

[0002] New energy vehicles have made great progress. 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. Among them, batteries, as the core components of new energy vehicles, have high requirements in terms of performance and production quality.

[0003] In battery technology, a battery cell includes an outer shell and an electrode assembly accommodated in the outer shell, the outer shell includes an end cap and a shell, the interior of the shell forms a receiving cavity for accommodating the electrode assembly, and the receiving cavity has an opening, and the end cap is covered at the opening of the shell to realize the assembly of the battery cell. However, in the process of assembling the end cap and the shell of the existing battery cell, the shell is very likely to deform and expand outward, resulting in poor production quality of the battery cell and easily causing assembly impact when the battery cell is subsequently assembled into groups. Utility Model Content

[0004] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the production quality of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell, an electrode assembly and an end cover; the shell is formed with an opening at at least one end in a first direction; the electrode assembly is accommodated in the shell; the end cover closes the opening, the end cover comprises a cover body and a flange portion, the flange portion is connected to the outer edge of the cover body and is bent toward one side of the cover body in the first direction, the flange portion is arranged around the cover body, at least part of the flange portion is inserted into the shell along the first direction, and the flange portion abuts against the inner circumferential surface of the shell; wherein a first groove is provided on the end cover, and the first groove is configured to reduce the extrusion force applied by the flange portion to the inner circumferential surface of the shell.

[0006] In the above technical solution, the end cover is provided with a cover body and a flange portion, the flange portion is connected to the outer edge of the cover body and is arranged around the cover body, and the flange portion is arranged as a structure bent toward one side of the cover body in a first direction, so that the flange portion is inserted into the shell from the opening along the first direction and abuts against the inner circumferential surface of the shell, thereby realizing the assembly between the end cover and the shell, wherein a first groove is provided on the end cover, and the first groove is configured to reduce the extrusion force applied by the flange portion to the inner circumferential surface of the shell, that is, after the first groove is provided on the end cover, the force required for the end cover to deform in the radial direction of the end cover can be reduced, so that the end cover is easier to deform when the flange portion is inserted into the shell and abuts against the inner circumferential surface of the shell for assembly, thereby reducing the extrusion force applied by the flange portion to the inner circumferential surface of the shell when inserted into the shell, so as to alleviate the phenomenon of deformation and outward expansion of the shell, thereby improving the consistency of the outer circumferential surface of the shell, which is beneficial to improving the production quality of the battery cell, and can reduce the assembly influence of the battery cell shell expansion on the subsequent assembly of the battery cell into groups.

[0007] In some embodiments, the first groove is an annular groove extending along the circumference of the flange portion.

[0008] In the above technical solution, by setting the first groove as an annular structure extending along the circumference of the flange portion, the first groove can reduce the force required for deformation of any position on the outer periphery of the end cover in the radial direction of the end cover, which is beneficial to further reduce the difficulty of deformation of the end cover when the flange portion is inserted into the shell and assembled with the inner circumference of the shell. The extrusion force applied to the inner circumference of the shell by any position on the outer periphery of the flange portion can be reduced, so as to further alleviate the phenomenon of deformation and outward expansion of the shell, and then the consistency of the outer circumference of the shell can be further improved, so as to improve the production quality of the battery cell.

[0009] In some embodiments, the first groove is disposed on the cover body.

[0010] In the above technical solution, by setting the first groove on the cover body, on the one hand, the difficulty of setting the first groove on the end cover can be reduced, which is beneficial to reducing the processing difficulty of the end cover to improve the production efficiency of the battery cell; on the other hand, while reducing the impact on the structural strength of the flange part, it can also achieve the reduction of the extrusion force applied by the flange part to the inner circumferential surface of the shell, so that it can not only improve the assembly effect between the flange part and the shell, but also alleviate the phenomenon of deformation and outward expansion of the shell.

[0011] In some embodiments, along the first direction, a protrusion is formed on one side of the cover body, and a second groove is formed on the other side corresponding to the position of the protrusion; wherein, along the first direction, the flange portion and the protrusion are located on the same side of the cover body, the flange portion surrounds the outer side of the protrusion, and a third groove is formed between the flange portion and the protrusion, and the first groove is arranged on the bottom wall of the third groove.

[0012] In the above technical solution, a protrusion is protruding from one side of the cover body in the first direction, and a second groove is provided at a position corresponding to the protrusion on the other side, and the flange portion surrounds the outer side of the protrusion, so that a third groove is formed between the flange portion and the protrusion. By arranging the first groove on the groove bottom wall of the third groove formed by the flange portion and the protrusion, the end cover adopting this structure can further reduce the difficulty of deformation of the end cover in the radial direction of the end cover, and can realize the first groove closer to the flange portion connected to the outer edge of the cover body, so that the end cover is easier to deform when the flange portion is inserted into the shell and abuts against the inner circumferential surface of the shell for assembly, which is beneficial to further reduce the extrusion force applied by the flange portion to the inner circumferential surface of the shell, so as to alleviate the phenomenon of deformation and outward expansion of the shell.

[0013] In some embodiments, the first groove is arranged on the side of the groove bottom wall of the third groove away from the electrode assembly, the third groove includes a first groove bottom surface, a first groove side surface and a second groove side surface, the first groove bottom surface connects the first groove side surface and the second groove side surface, the first groove side surface is formed at the flange portion, and the second groove side surface is formed at the protruding portion; wherein the groove wall surface of the first groove connects the first groove side surface and the first groove bottom surface.

[0014] In the above technical solution, the first groove side of the third groove is formed on the flange portion, and the first groove bottom surface and the first groove side surface of the third groove are interconnected through the groove wall surface of the first groove, so that the first groove is a structure arranged close to the corner area of ​​the first groove bottom surface and the first groove side surface of the third groove, so that the first groove can be close to the flange portion, so that the end cover is easier to deform when the flange portion is inserted into the shell and abuts against the inner circumferential surface of the shell for assembly, which is beneficial to further reduce the extrusion force applied by the flange portion to the inner circumferential surface of the shell, so as to further alleviate the phenomenon of deformation and outward expansion of the shell.

[0015] In some embodiments, along the first direction, the minimum residual thickness of the first groove is D, satisfying 0.1 mm≤D≤0.4 mm.

[0016] In the above technical scheme, the minimum residual thickness of the first groove is 0.1mm to 0.4mm, so that the minimum thickness of the area of ​​the cover body where the first groove is provided in the first direction is 0.1mm to 0.4mm. On the one hand, by setting the minimum residual thickness of the first groove to be greater than or equal to 0.1mm, the structural strength of the area of ​​the cover body where the first groove is provided is improved, which is beneficial to reduce the risk of breakage or damage in the area of ​​the cover body where the first groove is provided during use or assembly. On the other hand, by setting the minimum residual thickness of the first groove to be less than or equal to 0.4mm, the strength of the area of ​​the cover body where the first groove is provided is too high, which causes the end cover to be inserted into the shell and abut against the inner circumferential surface of the shell for assembly, thereby reducing the extrusion force applied by the flange to the inner circumferential surface of the shell.

[0017] In some embodiments, along the first direction, the first groove is disposed on a side of the cover body facing away from the electrode assembly.

[0018] In the above technical solution, by arranging the first groove on the side of the cover body away from the electrode assembly in the first direction, the first groove is directed to the outside of the battery cell, thereby reducing the difficulty of processing the first groove on the cover body of the end cover, which is beneficial to improving the manufacturing efficiency of the battery cell.

[0019] In some embodiments, along the first direction, the first groove is disposed on a side of the cover body facing the electrode assembly.

[0020] In the above technical solution, by arranging the first groove on the side of the cover body facing the electrode assembly in the first direction, the first groove is directed toward the interior of the battery cell, thereby preventing impurities or particles in the external environment from accumulating in the first groove and reducing the risk of the groove wall of the first groove being exposed to the outside and being corroded and oxidized by the external environment.

[0021] In some embodiments, a protrusion is formed on one side of the cover body along the first direction, and the protrusion and the flange portion are both located on the side of the cover body facing away from the electrode assembly; wherein, along the first direction, the flange portion has a first end face facing away from the electrode assembly, and the protrusion has a first surface facing away from the electrode assembly, and the first surface is farther away from the electrode assembly than the first end face.

[0022] In the above technical scheme, by setting the protruding portion of the cover body facing away from the first surface of the electrode assembly in the first direction to be farther away from the electrode assembly than the first end surface of the flange portion facing away from the electrode assembly in the first direction, on the one hand, the flange portion can be protected to a certain extent through the support and blocking of the first surface to alleviate the wear of the flange portion, thereby improving the assembly effect between the flange portion and the shell; on the other hand, the influence of the flange portion on the height dimension of the battery cell in the first direction after protruding from the cover body can be reduced, which is beneficial to reducing the difficulty of subsequent assembly of the battery cell and reducing the interference effect of the flange portion during the subsequent assembly of the battery cell.

[0023] In some embodiments, along the first direction, a distance L between the first surface and the first end surface satisfies 0.1 mm≤L≤0.6 mm.

[0024] In the above technical solution, the distance between the first surface of the protrusion and the first end face of the flange portion is 0.1mm to 0.6mm. On the one hand, by setting the spacing between the first surface and the first end face to be greater than or equal to 0.1mm to increase the distance between the first surface and the first end face, it is beneficial to improve the protection effect of the first surface on the flange portion, so as to alleviate the wear of the flange portion, and can further reduce the influence of the flange portion on the height dimension of the battery cell in the first direction, so as to reduce the difficulty of subsequent assembly of the battery cell and the interference risk caused by the flange portion during the subsequent assembly of the battery cell. On the other hand, by setting the spacing between the first surface and the first end face to be less than or equal to 0.6mm, the phenomenon that the first surface of the protrusion is too far away from the electrode assembly compared with the first end face can be alleviated, which is beneficial to reduce the difficulty of forming the protrusion on the cover body of the end cover, and can save the space occupied by the battery cell in the first direction, so as to improve the space utilization rate of the battery cell.

[0025] In some embodiments, along the first direction, a second groove is formed on a side of the cover body away from the protrusion and corresponding to a position of the protrusion.

[0026] In the above technical solution, a second groove is formed in an area corresponding to the protrusion on one side of the cover body facing the electrode assembly, so that the protrusion of the cover body is a structure that can be formed by stamping, so that the protrusion and the second groove are respectively formed on both sides of the cover body of the end cover along the first direction, which is beneficial to reduce the manufacturing difficulty of the end cover and improve the processing efficiency of the end cover.

[0027] In some embodiments, along the first direction, the second groove has a second groove bottom surface facing the electrode assembly, the second groove bottom surface and the first surface are respectively located on both sides of the cover body, and the second groove bottom surface is protrudingly provided with reinforcing ribs.

[0028] In the above technical solution, by convexly providing a reinforcing rib on the second groove bottom surface of the second groove, the structural strength of the area of ​​the protrusion corresponding to the second groove can be improved, so as to improve the anti-deformation ability of the area of ​​the protrusion corresponding to the second groove, and then the supporting effect of the first surface of the protrusion can be effectively improved. In addition, by providing the reinforcing rib on the second groove bottom surface of the second groove, the reinforcing rib is a structure provided facing the inside of the battery cell, so that the wear of the reinforcing rib caused by collision with external components during use can be alleviated, which is conducive to improving the service life of the reinforcing rib, and can reduce the influence of the reinforcing rib on the height dimension of the battery cell in the first direction, which is conducive to reducing the difficulty of subsequent assembly of the battery cell and the interference risk caused by the reinforcing rib during the subsequent assembly of the battery cell.

[0029] In some embodiments, a fourth groove is formed on the first surface at a position corresponding to the reinforcing rib along the first direction.

[0030] In the above technical solution, by forming a fourth groove in the area corresponding to the reinforcing rib on the first surface, the reinforcing rib on the bottom surface of the second groove of the second groove is a structure that can be formed by stamping, so as to form a reinforcing rib on the bottom surface of the second groove and form a fourth groove on the first surface, which is beneficial to reduce the manufacturing difficulty of the end cover and improve the processing efficiency of the end cover.

[0031] In some embodiments, along the first direction, the flange portion is bent toward a side of the cover body away from the electrode assembly.

[0032] In the above technical solution, by setting the flange portion as a structure that bends toward the side of the cover body away from the electrode assembly, it is possible to facilitate the flange portion to be inserted into the shell from the opening of the shell and abut against the inner circumferential surface of the shell, which is beneficial to reducing the difficulty of assembly between the end cover and the shell, and can alleviate the phenomenon of the flange portion being stuck with one end of the shell during the process of being inserted into the shell.

[0033] In some embodiments, the flange portion has a first outer circumferential surface abutting against the inner circumferential surface of the shell, and along the first direction, the flange portion has a first end surface facing away from the electrode assembly, and the first end surface is connected to the first outer circumferential surface; wherein, the first outer circumferential surface is welded to the inner circumferential surface of the shell.

[0034] In the above technical solution, by welding the first outer peripheral surface of the flange part and the inner peripheral surface of the shell to each other, it is beneficial to further improve the connection reliability and firmness between the flange part and the shell, so as to further improve the assembly effect between the end cover and the shell, and can reduce the risk of the end cover and the shell falling off from each other during use.

[0035] In some embodiments, one end of the shell forming the opening in the first direction has a second end surface, and the second end surface is connected to the inner circumferential surface of the shell; wherein along the first direction, the second end surface is coplanar with the first end surface.

[0036] In the above technical solution, by setting the second end face connected to the shell and its inner circumference and the first end face connected to the flange part and its first outer circumference as a coplanar structure, the second end face of the shell and the first end face of the flange part are made flush with each other, which helps to reduce the difficulty of welding between the first outer circumference of the flange part and the inner circumference of the shell, and helps to improve the welding quality between the first outer circumference of the flange part and the inner circumference of the shell.

[0037] In some embodiments, the flange portion includes a first part and a second part; the first part is connected to the outer edge of the cover body, the first part is arranged around the cover body, and the first part has a first outer peripheral surface abutting the inner peripheral surface of the shell; the second part is connected to an end of the first part away from the electrode assembly, and the second part protrudes from the first outer peripheral surface; wherein, along the first direction, the end of the shell forming the opening has a second end surface, the second end surface is connected to the inner peripheral surface of the shell, and the second part abuts against the second end surface.

[0038] In the above technical solution, the flange portion is provided with a first part and a second part, the first part has a first outer circumferential surface abutting against the inner circumferential surface of the shell, the second part is connected to the first part and protrudes from the first outer circumferential surface of the first part, and the second part is arranged to abut against the second end face of the shell along the first direction, so that part of the flange portion is a structure overlapped on the end of the shell with an opening formed along the first direction, so that the second part of the flange portion can also play a certain role of limiting and positioning, which is conducive to alleviating the phenomenon that the flange portion of the end cover is transitionally inserted into the shell, and is conducive to improving the assembly accuracy and assembly quality between the end cover and the shell.

[0039] In some embodiments, the second portion has a second surface abutting against the second end surface in the first direction, and the second surface is connected to the second end surface by welding.

[0040] In the above technical solution, by welding the second surface of the second part and the second end face of the shell to each other, on the one hand, the connection reliability and firmness between the flange part and the shell can be further improved, so as to further improve the assembly effect between the end cover and the shell, and can reduce the risk of the end cover and the shell falling off from each other during use; on the other hand, the welding area between the flange part and the shell can be away from the gap between the first outer peripheral surface of the first part and the inner peripheral surface of the shell, thereby alleviating the phenomenon that the light beam or heat generated when the flange part and the shell are welded to each other directly enters the shell through the gap between the first outer peripheral surface of the first part and the inner peripheral surface of the shell and burns the electrode assembly, which is beneficial to improving the production quality of the battery cell.

[0041] In some embodiments, the second portion is disposed around the first portion.

[0042] In the above technical solution, the second part is set as an annular structure to further enhance the effect of the second part abutting against the second end face of the shell in the first direction, thereby achieving the function of limiting and positioning the entire periphery of the end cover, which is beneficial to further enhance the limiting and positioning effect of the second part, and further enhance the assembly accuracy and assembly quality between the end cover and the shell.

[0043] In some embodiments, the flange portion has a first outer circumferential surface abutting against the inner circumferential surface of the shell, and the cover body has a third surface facing the electrode assembly, the third surface is perpendicular to the first direction, and the third surface is set at an obtuse angle to the first outer circumferential surface.

[0044] In the above technical scheme, by setting the first outer peripheral surface of the flange part and the third surface of the cover body facing the electrode assembly as an obtuse angle structure, the first outer peripheral surface of the flange part is an inclined structure, and the first outer peripheral surface of the flange part is closer to the electrode assembly in the first direction than the end of the first outer peripheral surface of the flange part far away from the electrode assembly in the first direction. The inner peripheral surface of the shell is farther away from the end cover in the radial direction. Therefore, on the one hand, the first outer peripheral surface of the flange part can play a certain guiding role when the flange part is inserted into the shell, so as to facilitate the insertion of the flange part in the shell, which is beneficial to reducing the difficulty of assembly between the end cover and the shell. On the other hand, it can also achieve a closer fit between the flange part and the inner peripheral surface of the shell, which is beneficial to reducing the size of the gap between the first outer peripheral surface of the flange part and the inner peripheral surface of the shell, so as to improve the assembly quality between the end cover and the shell.

[0045] In some embodiments, the included angle between the third surface and the first outer peripheral surface is α, satisfying 90°<α≤93°.

[0046] In the above technical scheme, the angle between the third surface and the first outer peripheral surface is greater than 90 degrees and less than or equal to 93 degrees, that is, the inclination angle of the first outer peripheral surface of the flange portion is less than or equal to 3 degrees, thereby alleviating the phenomenon that the inclination angle of the first outer peripheral surface of the flange portion is too large, causing the flange portion to be unable to be assembled into the shell or causing excessive difficulty in assembling the flange portion and the shell, and can alleviate the phenomenon that the end cover is excessively deformed when the flange portion is inserted into the shell and abuts against the inner peripheral surface of the shell for assembly.

[0047] In some embodiments, the shell includes an integrally formed bottom wall and side wall, the side wall is arranged around the bottom wall, along the first direction, one end of the side wall is connected to the bottom wall, and the other end is enclosed to form the opening, and the side wall and the bottom wall jointly define a accommodating cavity for accommodating the electrode assembly; wherein the flange portion abuts against the inner circumferential surface of the side wall.

[0048] In the above technical solution, the shell includes a bottom wall and a side wall, the side wall is arranged on the outside of the bottom wall, and one end of the side wall in the first direction is connected to the bottom wall, and the other end is enclosed to form an opening, so that the flange portion of the end cover is inserted into the side wall from the opening and abuts against the inner circumferential surface of the side wall to complete the assembly of the battery cell. The structure is simple and easy to implement, which is conducive to reducing the processing difficulty of the shell of the battery cell.

[0049] In some embodiments, the flange portion is interference fit with the inner circumference of the shell.

[0050] In the above technical solution, by setting the flange portion as a structure that is interference fit with the inner circumferential surface of the shell, the gap size between the flange portion and the inner circumferential surface of the shell can be further reduced after the end cover is deformed along the radial direction of the end cover, and the connection reliability between the flange portion and the shell can be further improved, thereby further improving the assembly effect between the end cover and the shell, thereby reducing the risk of the end cover and the shell falling off from each other during use.

[0051] In some embodiments, the shell is cylindrical, and the central axis of the shell extends along the first direction.

[0052] In the above technical solution, the shell of the battery cell is set to be cylindrical so as to facilitate processing to form a battery cell with a cylindrical structure, so that the battery cell has the advantages of high capacity, long cycle life, and a wide range of ambient temperature.

[0053] In a second aspect, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.

[0054] In a third aspect, an embodiment of the present application further provides an electrical device, comprising the above-mentioned battery cell, wherein the battery cell is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] 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.

[0056] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0057] Figure 2 An exploded view of the structure of a battery provided in some embodiments of the present application;

[0058] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0059] Figure 4 An exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0060] Figure 5 A cross-sectional view of a battery cell provided for some embodiments of the present application;

[0061] Figure 6 for Figure 5 A partial enlarged view of the battery cell at A shown;

[0062] Figure 7 A schematic diagram of the structure of an end cover of a battery cell provided in some embodiments of the present application;

[0063] Figure 8 A cross-sectional view of an end cover of a battery cell provided in some embodiments of the present application;

[0064] Fig. 9 for Figure 8 A partial enlarged view of position B of the end cap shown;

[0065] Fig.10 A cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0066] Fig.11 for Fig.10 A partial enlarged view of the battery cell at position C shown;

[0067] Fig.12 A schematic diagram of the structure of an end cover of a battery cell provided in some other embodiments of the present application;

[0068] Fig.13 A cross-sectional view of an end cover of a battery cell provided in some other embodiments of the present application;

[0069] Fig.14 for Fig.13 A partial enlarged view of the end cap at D shown;

[0070] Fig.15 A cross-sectional view of a battery cell provided in some other embodiments of the present application;

[0071] Fig.16 for Fig.15 A partial enlarged view of the battery cell at position E shown;

[0072] Fig.17 A schematic diagram of the structure of an end cover of a battery cell provided in some further embodiments of the present application;

[0073] Fig.18 A cross-sectional view of an end cover of a battery cell provided in some further embodiments of the present application;

[0074] Fig.19 for Fig.18 A partial enlarged view of point F of the end cap is shown.

[0075] Icon: 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery cell; 21-shell; 211-opening; 212-accommodation cavity; 213-bottom wall; 214-side wall; 215-second end surface; 22-electrode assembly; 221-ear; 23-end cover; 231-cover body; 2311-notched groove; 2312-protrusion; 2312a-first surface; 2312b-fourth groove; 2313-second groove; 2313a-bottom surface of second groove ; 2314-reinforcing rib; 2315-third surface; 232-flanged portion; 2321-first end face; 2322-first outer peripheral surface; 2323-first part; 2324-second part; 2324a-second surface; 233-first groove; 234-third groove; 2341-bottom surface of first groove; 2342-side surface of first groove; 2343-side surface of second groove; 24-electrode terminal; 25-current collecting member; 26-pressure relief mechanism; 200-controller; 300-motor; X-first direction; Y-radial direction of end cover. DETAILED DESCRIPTION

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] The term "plurality" used in the present application refers to two or more (including two).

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base 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.).

[0089] 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 can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of lithium-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, lithium nickel cobalt manganese oxide (such as LiNi 1 / 3 Co 1 / 3 Mn 1 / 3O2 (also referred to as NCM 333 )、LiNi 0.5 Co 0.2 Mn 0.3 O2 (also referred to as NCM 523 )、LiNi 0.5 Co 0.25 Mn 0.25 O2 (also referred to as NCM 211 )、LiNi 0.6 Co 0.2 Mn 0.2 O2 (also referred to as NCM 622 )、LiNi 0.8 Co 0.1 Mn 0.1 O2 (also referred to as NCM 811 ), lithium nickel cobalt aluminum oxide (such as LiNi 0.85 Co 0.15 Al 0.05 O2) and its modified compounds, etc.

[0090] In some embodiments, the positive electrode may be a foamed metal. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. When the foamed metal is used as the positive electrode, the positive electrode active material may not be provided on the surface of the foamed metal, but of course, the positive electrode active material may also be provided. As an example, a lithium source material, potassium metal or sodium metal may also be filled or / and deposited in the foamed metal, and the lithium source material is lithium metal and / or a lithium-rich material.

[0091] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0092] As an example, the negative electrode current collector may be a metal foil, a foamed metal or a composite current collector. For example, as the metal foil, aluminum or stainless steel treated with silver, stainless steel, copper, aluminum, nickel, carbon electrode, nickel or titanium, etc. may be used. The foamed metal may be a nickel foam, a copper foam, an aluminum foam, an alloy foam, etc. 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 (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.).

[0093] 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.

[0094] 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.

[0095] 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. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0096] 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.

[0097] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0098] 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.

[0099] As an example, the material of the separator may include at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or may be attached to the surface of the positive and negative electrodes.

[0100] 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.

[0101] 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 can be liquid, gel or solid. Among them, the liquid electrolyte includes an electrolyte salt and a solvent.

[0102] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bisfluorosulfonyl imide, lithium bistrifluoromethanesulfonyl imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalatoborate, lithium dioxalatoborate, lithium difluorodioxalatophosphate, and lithium tetrafluorooxalatophosphate.

[0103] In some embodiments, the solvent may include at least one of ethylene carbonate, propylene carbonate, ethyl methyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butylene carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, cyclopentane, dimethyl sulfone, methyl ethyl sulfone and diethyl sulfone. The solvent may also be an ether solvent. The ether solvent may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyltetrahydrofuran, diphenyl ether and crown ether.

[0104] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0105] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0106] As an example, the polymer solid electrolyte may be polyether (polyethylene oxide), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, a single ion polymer, polyionic liquid-lithium salt, cellulose, and the like.

[0107] As an example, the inorganic solid electrolyte may include an oxide solid electrolyte (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON film), a sulfide solid electrolyte (crystalline lithium superion conductor (lithium germanium phosphosulfide, silver germanium sulfide), amorphous sulfide) and one or more of a halide solid electrolyte, a nitride solid electrolyte and a hydride solid electrolyte.

[0108] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0109] 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.

[0110] In some embodiments, the electrode assembly is a laminate structure.

[0111] As an example, a plurality of positive electrode sheets and a plurality of negative electrode sheets may be provided respectively, and the plurality of positive electrode sheets and the plurality of negative electrode sheets may be alternately stacked.

[0112] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0113] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of folded sections that are stacked.

[0114] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0115] As an example, the separator may be disposed continuously, and may be disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0116] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0117] 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.

[0118] 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.

[0119] As an example, the battery cell may be a cylindrical battery cell, a prismatic battery cell, a soft-pack 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 battery, such as a hexagonal battery, etc.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0125] 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. The development of battery technology must consider many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters.

[0126] For a general battery cell, the battery cell includes an outer shell and an electrode assembly accommodated in the outer shell, the outer shell includes an end cap and a shell, the interior of the shell forms a accommodating cavity with an opening, and the end cap covers the opening to form an outer shell for accommodating the electrode assembly. In the related art, in order to improve the connection reliability and stability between the end cap and the shell, the end cap is usually first inserted into the accommodating cavity of the shell from the opening of the shell, so that the outer peripheral surface of the end cap can abut or interference fit with the inner peripheral surface of the shell, and then the end cap and the shell are welded to each other, so as to further improve the connection strength between the end cap and the shell. However, a battery cell with this structure is very likely to cause the shell to expand outward and deform during the assembly of the end cap and the shell, resulting in poor consistency of the outer peripheral surface of the shell, which is not conducive to improving the production quality of the battery cell, and is very likely to cause large assembly errors when the battery cells are subsequently assembled into groups, thereby easily causing assembly impacts when the battery cells are subsequently assembled into groups.

[0127] Based on the above considerations, in order to solve the problem of poor production quality of battery cells, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and an end cover. An opening is formed at least at one end of the shell in the first direction. The electrode assembly is accommodated in the shell. The end cover closes the opening, and the end cover includes a cover body and a flange portion, the flange portion is connected to the outer edge of the cover body and is bent toward one side of the cover body in the first direction, the flange portion is arranged around the cover body, at least part of the flange portion is inserted into the shell along the first direction, and the flange portion abuts against the inner circumferential surface of the shell. A first groove is provided on the end cover, and the first groove is configured to reduce the extrusion force applied by the flange portion to the inner circumferential surface of the shell.

[0128] In a battery cell of this structure, the end cover is provided with a cover body and a flange portion, the flange portion is connected to the outer edge of the cover body and is arranged around the cover body, and the flange portion is arranged as a structure bent toward one side of the cover body in a first direction, so that the flange portion can be inserted into the shell from the opening along the first direction and abut against the inner circumferential surface of the shell, thereby realizing the assembly between the end cover and the shell, wherein a first groove is provided on the end cover, and the first groove is configured to reduce the extrusion force applied by the flange portion to the inner circumferential surface of the shell, that is, after the first groove is provided on the end cover, the force required for the end cover to deform in the radial direction of the end cover can be reduced, so that the end cover is easier to deform when the flange portion is inserted into the shell and abuts against the inner circumferential surface of the shell for assembly, thereby reducing the extrusion force applied by the flange portion to the inner circumferential surface of the shell when inserted into the shell, so as to alleviate the phenomenon of deformation and outward expansion of the shell, thereby improving the consistency of the outer circumferential surface of the shell, which is beneficial to improving the production quality of the battery cell, and can reduce the assembly influence of the battery cell shell expansion on the subsequent assembly of the battery cell into groups.

[0129] 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 the battery cell shell being deformed outward, thereby improving the production quality of the battery cell and reducing the impact on the assembly of the battery cell when it is subsequently assembled into groups.

[0130] 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.

[0131] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device in an embodiment of the present application.

[0132] Please refer to Figure 1 , Figure 1A 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.

[0133] 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.

[0134] 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 is as follows. 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 .

[0135] 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.

[0136] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid or a cube. Figure 2 In the embodiment, the box body 10 is in the shape of a rectangular parallelepiped.

[0137] 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 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 the whole may be accommodated in the box 10.

[0138] 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 .

[0139] 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 in a rectangular parallelepiped, a cylinder, a prism or other shapes. For example, Figure 3 In the figure, the battery cell 20 is a cylindrical structure.

[0140] According to some embodiments of the present application, referring to Figure 3 , and please refer to Figure 4 , Figure 5 , Figure 6 and Figure 7 , 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 cross-sectional view of a battery cell 20 provided in some embodiments of the present application, Figure 6 for Figure 5 The partial enlarged view of the battery cell 20 at A shown in FIG. Figure 7A schematic diagram of the structure of the end cover 23 of the battery cell 20 provided in some embodiments of the present application. The present application provides a battery cell 20, which includes a shell 21, an electrode assembly 22 and an end cover 23. The shell 21 is formed with an opening 211 at at least one end in the first direction X. The electrode assembly 22 is accommodated in the shell 21. The end cover 23 closes the opening 211, and the end cover 23 includes a cover body 231 and a flange 232, the flange 232 is connected to the outer edge of the cover body 231 and is bent toward one side of the cover body 231 in the first direction X, the flange 232 is arranged around the cover body 231, at least part of the flange 232 is inserted into the shell 21 along the first direction X, and the flange 232 abuts against the inner circumferential surface of the shell 21. A first groove 233 is provided on the end cover 23, and the first groove 233 is configured to reduce the extrusion force applied by the flange 232 to the inner circumferential surface of the shell 21.

[0141] The shell formed by the shell 21 and the end cap 23 can also be used to contain electrolytes, such as electrolytes. The shell formed by the shell 21 and the end cap 23 can be in various structural forms, such as a cylinder or a cuboid. Similarly, the shell 21 and the end cap 23 can also be made of various materials, such as aluminum or aluminum alloy.

[0142] A accommodating cavity 212 is formed inside the shell 21, and an opening 211 is formed at at least one end of the shell 21 in the first direction X, and the opening 211 is connected to the accommodating cavity 212, that is, a accommodating cavity 212 with an opening 211 is formed inside the shell 21, and the opening 211 is located at at least one end of the shell 21 in the first direction X, that is, the shell 21 is a hollow structure with an opening 211 formed at at least one end in the first direction X.

[0143] For example, in Figure 4 and Figure 5 In the embodiment, only one end of the shell 21 in the first direction X is formed with an opening 211, and the shell 21 may include a bottom wall 213 and a side wall 214, the side wall 214 is arranged around the bottom wall 213, along the first direction X, one end of the side wall 214 is connected to the bottom wall 213, and the other end is surrounded to form the opening 211, and the side wall 214 and the bottom wall 213 jointly define the accommodating cavity 212. Correspondingly, the flange portion 232 abuts against the inner circumference of the side wall 214 of the shell 21.

[0144] Optionally, the side wall 214 and the bottom wall 213 of the shell 21 can be an integrally formed structure, that is, the side wall 214 and the bottom wall 213 form the shell 21 through an integral molding process, such as stamping or casting. Of course, the side wall 214 and the bottom wall 213 of the shell 21 can also be a separately arranged structure, and the bottom wall 213 and the side wall 214 are connected to each other at one end away from the opening 211 in the first direction X.

[0145] For example, in Figure 4 In the embodiment, the side wall 214 and the bottom wall 213 of the shell 21 are integrally formed, that is, the side wall 214 and the bottom wall 213 are an integrated structure.

[0146] When assembling the battery cell 20 , the electrode assembly 22 may be placed in the housing 21 first, and the housing 21 may be filled with electrolyte. The end cap 23 may then be closed on the opening 211 of the housing 21 to complete the assembly of the battery cell 20 .

[0147] The shell 21 can be in various shapes, such as a cylinder, a cuboid, or a prism structure. The shape of the shell 21 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 21 with a cylindrical structure can be selected; if the electrode assembly 22 is a cuboid structure, a shell 21 with a cuboid structure can be selected. Of course, the structure of the end cap 23 can also be various, such as the end cap 23 being a plate-like structure or a hollow structure with one end open. For example, in Figure 3 and Figure 4 In the embodiment, the shell 21 is a cylindrical structure, and the end cover 23 is a circular plate structure.

[0148] Of course, it is understandable that the battery cell 20 is not limited to the above structure. For example, the battery cell 20 may include a shell 21 and two end covers 23. The shell 21 has a accommodating cavity 212 formed inside. The shell 21 has openings 211 formed at both ends in the first direction X. The two openings 211 are connected to the accommodating cavity 212, that is, the shell 21 is a hollow structure with openings 211 formed at both opposite ends in the first direction X. The two end covers 23 are respectively covered at the two openings 211 of the shell 21 to form a sealed connection to form an enclosed space for accommodating the electrode assembly 22 and the electrolyte. In other words, the shell 21 only includes a side wall 214, so that the shell 21 has openings 211 at both opposite ends in the first direction X, and the two end covers 23 are respectively covered on both sides of the shell 21 in the first direction X to close the corresponding openings 211.

[0149] In the embodiment of the present application, the end cover 23 closes the opening 211 , that is, the end cover 23 covers the opening 211 of the shell 21 in the first direction X and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.

[0150] Among them, the end cover 23 includes a cover body 231 and a flange portion 232, the flange portion 232 is connected to the outer edge of the cover body 231 and is bent toward one side of the cover body 231 in the first direction X, that is, the end cover 23 is formed with two parts, the cover body 231 and the flange portion 232, the flange portion 232 is a structure connected to the outer edge of the cover body 231 and bent toward one side of the cover body 231 in the first direction X, that is, the flange portion 232 is a structure formed by bending the edge of the end cover 23 along the first direction X toward or away from the electrode assembly 22, so that the bent part of the end cover 23 is the bent part, and the unbent part is the cover body 231, so that the flange portion 232 is a structure connected to the outer edge of the cover body 231.

[0151] The flange portion 232 is disposed around the cover body 231 , that is, the flange portion 232 is an annular structure extending along the circumferential direction of the outer edge of the cover body 231 .

[0152] At least part of the flange portion 232 is inserted into the housing 21 along the first direction X, that is, the flange portion 232 may be inserted into the housing 21 from the opening 211 only along the first direction X, or the flange portion 232 may be entirely inserted into the housing 21. Figure 6 In the embodiment, the flange portion 232 is entirely located in the shell 21. Of course, in other embodiments, the flange portion 232 may be partially inserted into the shell 21 along the first direction X, and the other part may extend beyond the shell 21 along the first direction X to form an end of the opening 211.

[0153] The flange portion 232 abuts against the inner circumference of the shell 21, that is, the flange portion 232 is a structure that abuts against the inner circumference of the shell 21 in the radial direction Y of the end cover. For example, the flange portion 232 is interference fit with the inner circumference of the shell 21. Of course, in other embodiments, the flange portion 232 can also be welded to the shell 21.

[0154] A first groove 233 is provided on the end cover 23, and the first groove 233 is configured to reduce the extrusion force applied by the flange portion 232 to the inner circumferential surface of the shell 21. That is to say, the first groove 233 can be provided on the cover body 231, or on the flange portion 232. The first groove 233 serves to reduce the force required for the end cover 23 to deform along the radial direction Y of the end cover, so that the end cover 23 can be more easily deformed when the flange portion 232 is inserted into the shell 21 and abuts against the inner circumferential surface of the shell 21, thereby making the reaction force applied by the flange portion 232 of the end cover 23 to the inner circumferential surface of the shell 21 smaller.

[0155] It should be noted that in the embodiment of the present application, the electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. The structure of the electrode assembly 22 can be of various types. For example, the electrode assembly 22 can be a wound structure formed by winding a positive electrode sheet, an isolation member, and a negative electrode sheet, or a stacked structure formed by stacking a positive electrode sheet, an isolation member, and a negative electrode sheet.

[0156] Exemplarily, the isolation member is an isolation membrane, and a main material of the isolation membrane may be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride.

[0157] Optionally, the electrode assembly 22 accommodated in the accommodation cavity 212 may be one or more. Figure 4 and Figure 5 In the embodiment, only one electrode assembly 22 is disposed inside the battery cell 20. Of course, in other embodiments, the number of electrode assemblies 22 accommodated in the accommodation cavity 212 may be two, three, four, five, six, seven or eight.

[0158] In some embodiments, see Figure 3 , Figure 4 and Figure 5 As shown, the battery cell 20 may further include an electrode terminal 24 , which is insulated and mounted on the bottom wall 213 of the housing 21 , and is electrically connected to the electrode assembly 22 to output or input electrical energy of the battery cell 20 .

[0159] It should be noted that the electrode terminal 24 is insulated and installed on the bottom wall 213 of the shell 21 , that is, there is no electrical connection between the electrode terminal 24 and the shell 21 .

[0160] Among them, see Figure 4 , Figure 5 and Figure 6As shown, the electrode assembly 22 has two pole ears 221, and the polarities of the two pole ears 221 are opposite, that is, the two pole ears 221 are respectively the positive pole ear and the negative pole ear of the electrode assembly 22, and are respectively used to output or input the positive electrode and the negative electrode of the electrode assembly 22. Along the first direction X, the two pole ears 221 are respectively formed at the two ends of the electrode assembly 22, and the pole ear 221 at one end of the electrode assembly 22 facing the bottom wall 213 in the first direction X is electrically connected to the electrode terminal 24, and the pole ear 221 at the other end is electrically connected to the end cover 23, so as to realize the input or output of the electric energy of the battery cell 20. Of course, in other embodiments, the battery cell 20 may also include two electrode terminals 24, the two electrode terminals 24 are respectively installed on the bottom wall 213 and the end cover 23, and the two electrode terminals 24 are respectively electrically connected to the two pole ears 221 at the two ends of the electrode assembly 22 in the first direction X, so as to realize the input or output of the electric energy of the battery cell 20. Similarly, in an embodiment where the battery cell 20 includes only one electrode terminal 24, the electrode terminal 24 can also be insulated and installed on the end cover 23, and the pole ear 221 at one end of the electrode assembly 22 facing the end cover 23 in the first direction X is electrically connected to the electrode terminal 24, and the pole ear 221 at the other end is electrically connected to the bottom wall 213 of the shell 21, so as to realize the input or output of electrical energy of the battery cell 20.

[0161] It should be noted that the tab 221 of the electrode assembly 22 is a component formed by mutually stacking and connecting the regions on the positive electrode sheet that are not coated with the positive electrode active material layer, or a component formed by mutually stacking and connecting the regions on the negative electrode sheet that are not coated with the negative electrode active material layer. If the tab 221 is used to output the positive electrode of the electrode assembly 22, the tab 221 is a component 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 tab 221 is used to output the negative electrode of the electrode assembly 22, the tab 221 is a component formed by mutually stacking and connecting the regions on the negative electrode sheet that are not coated with the negative electrode active material layer.

[0162] Exemplarily, the electrode terminal 24 may be made of a variety of materials. For example, the electrode terminal 24 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0163] In some embodiments, see Figure 4 , Figure 5 and Figure 6 As shown, the battery cell 20 may also include two current collecting components 25, both of which are arranged in the shell 21, one of the two current collecting components 25 is used to electrically connect one pole ear 221 and the electrode terminal 24, and the other current collecting component 25 is used to electrically connect the other pole ear 221 and the cover body 231 of the end cover 23, which is beneficial to reduce the assembly difficulty between the pole ear 221 and the electrode terminal 24 and between the pole ear 221 and the end cover 23.

[0164] Exemplarily, the material of the current collecting component 25 may be various, for example, the material of the current collecting component 25 may be copper, iron, aluminum, steel or aluminum alloy.

[0165] In some embodiments, see Figure 4 As shown, the battery cell 20 may further include a pressure relief mechanism 26 , which is disposed on the end cover 23 and 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.

[0166] Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the pressure relief mechanism 26 may also be disposed on the shell 21. Similarly, the pressure relief mechanism 26 and the end cover 23 or the shell 21 may be an integrally formed structure or a separately formed structure. If the pressure relief mechanism 26 and the end cover 23 or the shell 21 are a separate structure, the pressure relief mechanism 26 may be connected to the end cover 23 or the shell 21 by welding or the like. Correspondingly, the pressure relief mechanism 26 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; if the pressure relief mechanism 26 and the end cover 23 or the shell 21 are an integrally formed structure, the pressure relief mechanism 26 is an area where a weak structure is formed on the end cover 23 or the shell 21.

[0167] For example, refer to Figure 4 , and please refer to Figure 8 , Figure 8 The cross-sectional view of the end cover 23 of the battery cell 20 provided in some embodiments of the present application. The pressure relief mechanism 26 is provided on the end cover 23, and the pressure relief mechanism 26 and the end cover 23 are an integrally formed structure, and the cover body 231 of the end cover 23 is provided with a notched groove 2311 on one side facing the accommodating cavity 212 in the first direction X, so that the cover body 231 of the end cover 23 forms a weak structure in the area where the notched groove 2311 is provided, that is, the area where the notched groove 2311 is provided on the cover body 231 of the end cover 23 is the pressure relief mechanism 26.

[0168] In this embodiment, the end cover 23 is provided with a cover body 231 and a flange portion 232, and the flange portion 232 is connected to the outer edge of the cover body 231 and is arranged around the cover body 231. By setting the flange portion 232 as a structure bent toward one side of the cover body 231 in the first direction X, the flange portion 232 is inserted into the shell 21 from the opening 211 along the first direction X and abuts against the inner circumferential surface of the shell 21, thereby realizing the assembly between the end cover 23 and the shell 21, wherein a first groove 233 is provided on the end cover 23, and the first groove 233 is configured to reduce the extrusion force applied by the flange portion 232 to the inner circumferential surface of the shell 21, That is, by providing the first groove 233 on the end cover 23, the force required for the end cover 23 to deform in the radial direction Y of the end cover can be reduced, so that the end cover 23 is easier to deform when the flange portion 232 is inserted into the shell 21 and abuts against the inner circumferential surface of the shell 21 for assembly, thereby reducing the extrusion force applied by the flange portion 232 to the inner circumferential surface of the shell 21 when inserted into the shell 21, so as to alleviate the phenomenon of deformation and outward expansion of the shell 21, and further improve the consistency of the outer circumferential surface of the shell 21, which is beneficial to improving the production quality of the battery cell 20, and can reduce the assembly impact of the battery cell 20 after the shell 21 of the battery cell 20 expands outward when the battery cell 20 is subsequently assembled into groups.

[0169] According to some embodiments of the present application, see Figure 7 and Figure 8 As shown, the first groove 233 is an annular groove extending along the circumference of the flange portion 232. In other words, the first groove 233 is an annular structure extending along the circumference of the flange portion 232.

[0170] In this embodiment, by setting the first groove 233 as an annular structure extending along the circumference of the flange portion 232, the first groove 233 can reduce the force required for deformation of any position on the outer periphery of the end cover 23 in the radial direction Y of the end cover, which is beneficial to further reduce the difficulty of deformation of the end cover 23 when the flange portion 232 is inserted into the shell 21 and assembled with the inner circumferential surface of the shell 21, thereby reducing the extrusion force applied to the inner circumferential surface of the shell 21 by any position on the outer periphery of the flange portion 232, so as to further alleviate the phenomenon of deformation and outward expansion of the shell 21, and further improve the consistency of the outer circumferential surface of the shell 21, so as to improve the production quality of the battery cell 20.

[0171] According to some embodiments of the present application, referring to Figure 7 and Figure 8 , and further refer to Fig. 9 , Fig. 9 for Figure 8 The enlarged view of the part of the end cover 23 at B is shown. The first groove 233 is provided in the cover body 231 .

[0172] The first groove 233 may be disposed on a side of the cover body 231 facing the electrode assembly 22 in the first direction X, or may be disposed on a side of the cover body 231 away from the electrode assembly 22 in the first direction X. The first direction X is also the thickness direction of the cover body 231 .

[0173] It should be noted that in the embodiment where the first groove 233 is an annular groove extending along the circumference of the flange portion 232 , the flange portion 232 is a structure surrounding the outer side of the first groove 233 .

[0174] In this embodiment, by setting the first groove 233 on the cover body 231, on the one hand, the difficulty of setting the first groove 233 on the end cover 23 can be reduced, which is beneficial to reducing the processing difficulty of the end cover 23, so as to improve the production efficiency of the battery cell 20; on the other hand, while reducing the impact on the structural strength of the flange portion 232, it can also achieve the reduction of the extrusion force applied by the flange portion 232 to the inner circumferential surface of the shell 21, so that it can not only improve the assembly effect between the flange portion 232 and the shell 21, but also alleviate the phenomenon of deformation and outward expansion of the shell 21.

[0175] According to some embodiments of the present application, see Figure 7 , Figure 8 and Fig. 9 As shown, along the first direction X, a protrusion 2312 is formed on one side of the cover body 231, and a second groove 2313 is formed on the other side corresponding to the position of the protrusion 2312. Along the first direction X, the flange portion 232 and the protrusion 2312 are located on the same side of the cover body 231, the flange portion 232 surrounds the outer side of the protrusion 2312, and a third groove 234 is formed between the flange portion 232 and the protrusion 2312, and the first groove 233 is disposed on the groove bottom wall 213 of the third groove 234.

[0176] Among them, a protrusion 2312 is formed on one side of the cover body 231, and a second groove 2313 is formed on the other side corresponding to the position of the protrusion 2312. That is, the cover body 231 is a stamping structure with a protrusion 2312 formed on one side and a second groove 2313 formed on the other side.

[0177] The flange portion 232 and the protrusion 2312 are located on the same side of the cover body 231 , that is, the flange portion 232 and the protrusion 2312 are both protruding from the side of the cover body 231 facing the electrode assembly 22 or are both protruding from the side of the cover body 231 away from the electrode assembly 22 .

[0178] The flange portion 232 surrounds the outer side of the protrusion 2312, and a third groove 234 is formed between the flange portion 232 and the protrusion 2312. That is to say, the protrusion 2312 is located on the inner circumference of the flange portion 232 and is spaced apart from the flange portion 232 in the radial direction Y of the end cover, so that a third groove 234 is formed between the flange portion 232 and the protrusion 2312, and the third groove 234 is an annular groove structure surrounding the outer side of the flange portion 232.

[0179] The first groove 233 is arranged on the groove bottom wall 213 of the third groove 234, that is, the first groove 233 is arranged on the area of ​​the cover body 231 of the end cover 23 corresponding to the third groove 234. It can be arranged on the groove bottom surface of the third groove 234, or it can be arranged on the area of ​​the cover body 231 that is away from the third groove 234 and corresponds to the third groove 234 in the first direction X. That is to say, in the radial direction Y of the end cover, the first groove 233 is located between the protrusion 2312 and the flange portion 232.

[0180] It should be noted that in the embodiment where the first groove 233 is an annular groove extending along the circumference of the flange portion 232 , the first groove 233 is an annular groove structure surrounding the outer side of the protruding portion 2312 .

[0181] In this embodiment, a protrusion 2312 is protruded on one side of the cover body 231 in the first direction X, and a second groove 2313 is provided on the other side at a position corresponding to the protrusion 2312, and the flange portion 232 surrounds the outer side of the protrusion 2312, so that a third groove 234 is formed between the flange portion 232 and the protrusion 2312. By arranging the first groove 233 on the groove bottom wall 213 of the third groove 234 formed by the flange portion 232 and the protrusion 2312, the end cover 23 adopting such a structure can further reduce the deformation difficulty of the end cover 23 in the radial direction Y of the end cover, and can realize that the first groove 233 is closer to the flange portion 232 connected to the outer edge of the cover body 231, so that the end cover 23 is easier to deform when the flange portion 232 is inserted into the shell 21 and abuts against the inner circumferential surface of the shell 21 for assembly, which is beneficial to further reduce the extrusion force applied by the flange portion 232 to the inner circumferential surface of the shell 21, so as to alleviate the phenomenon of deformation and outward expansion of the shell 21.

[0182] In some embodiments, see Fig. 9As shown, the first groove 233 is arranged on the side of the groove bottom wall 213 of the third groove 234 away from the electrode assembly 22, and the third groove 234 includes a first groove bottom surface 2341, a first groove side surface 2342 and a second groove side surface 2343. The first groove bottom surface 2341 connects the first groove side surface 2342 and the second groove side surface 2343. The first groove side surface 2342 is formed at the flange portion 232, and the second groove side surface 2343 is formed at the protruding portion 2312. The groove wall surface of the first groove 233 connects the first groove side surface 2342 and the first groove bottom surface 2341.

[0183] The first groove 233 is disposed on a side of the groove bottom wall 213 of the third groove 234 away from the electrode assembly 22 , that is, the first groove 233 is disposed on the first groove bottom surface 2341 of the third groove 234 .

[0184] The third groove 234 includes a first groove bottom surface 2341, a first groove side surface 2342 and a second groove side surface 2343. The first groove bottom surface 2341 connects the first groove side surface 2342 and the second groove side surface 2343. The first groove side surface 2342 is formed on the flange portion 232, that is, the surface of the flange portion 232 facing the protrusion 2312 on the radial direction Y of the end cover forms the first groove side surface 2342 of the third groove 234, the surface of the protrusion 2312 facing the flanging portion 232 on the radial direction Y of the end cover forms the second groove side surface 2343 of the third groove 234, and the first groove side surface 2342 and the second groove side surface 2343 are connected through the first groove bottom surface 2341. Correspondingly, the first groove 233 is arranged on the first groove bottom surface 2341 of the third groove 234.

[0185] The groove wall surface of the first groove 233 connects the first groove side surface 2342 and the first groove bottom surface 2341, that is, the first groove 233 is arranged at one end of the first groove bottom surface 2341 close to the flange portion 232 in the radial direction Y of the end cover, so that the first groove 233 is a structure arranged in the corner area of ​​the first groove bottom surface 2341 and the first groove side surface 2342 close to the third groove 234, so that the groove wall surface of the first groove 233 is a structure connecting the first groove side surface 2342 and the first groove bottom surface 2341.

[0186] In this embodiment, the first groove side 2342 of the third groove 234 is formed on the flange portion 232, and the first groove bottom surface 2341 and the first groove side surface 2342 of the third groove 234 are interconnected through the groove wall surface of the first groove 233, so that the first groove 233 is a structure arranged close to the corner area of ​​the first groove bottom surface 2341 and the first groove side surface 2342 of the third groove 234, thereby enabling the first groove 233 to be close to the flange portion 232, so that the end cover 23 is more easily deformed when the flange portion 232 is inserted into the shell 21 and abuts against the inner circumferential surface of the shell 21 for assembly, which is beneficial to further reduce the extrusion force applied by the flange portion 232 to the inner circumferential surface of the shell 21, so as to further alleviate the phenomenon of deformation and outward expansion of the shell 21.

[0187] According to some embodiments of the present application, see Fig. 9 As shown, along the first direction X, the minimum residual thickness of the first groove 233 is D, satisfying 0.1 mm≤D≤0.4 mm.

[0188] Among them, the minimum residual thickness of the first groove 233 is D, that is, along the first direction X, the cover body 231 is provided with the first groove 233 and the minimum thickness of the area corresponding to the first groove 233 is D, that is, the minimum thickness of the groove bottom wall 213 of the first groove 233 in the first direction X is D.

[0189] Exemplarily, the minimum residual thickness D of the first groove 233 may be 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.15 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.25 mm, 0.28 mm, 0.3 mm, 0.32 mm, 0.35 mm, 0.38 mm or 0.4 mm, etc.

[0190] In this embodiment, the minimum residual thickness of the first groove 233 is 0.1mm to 0.4mm, so that the minimum thickness of the area of ​​the cover body 231 where the first groove 233 is provided in the first direction X is 0.1mm to 0.4mm. On the one hand, by setting the minimum residual thickness of the first groove 233 to be greater than or equal to 0.1mm, the structural strength of the area of ​​the cover body 231 where the first groove 233 is provided is improved, which is beneficial to reduce the risk of breakage or damage in the area of ​​the cover body 231 where the first groove 233 is provided during use or assembly. On the other hand, by setting the minimum residual thickness of the first groove 233 to be less than or equal to 0.4mm, the strength of the area of ​​the cover body 231 where the first groove 233 is provided is too large, which causes the deformation effect of the end cover 23 to be poor when the flange portion 232 is inserted into the shell 21 and abuts against the inner circumferential surface of the shell 21 for assembly, thereby reducing the extrusion force applied by the flange portion 232 to the inner circumferential surface of the shell 21.

[0191] In some embodiments, see Fig. 9 As shown, along the first direction X, the first groove 233 is disposed on a side of the cover body 231 away from the electrode assembly 22 .

[0192] In the embodiment where the first groove 233 is disposed on the groove bottom wall 213 of the third groove 234 , the first groove 233 is disposed on the first groove bottom surface 2341 of the third groove 234 .

[0193] In this embodiment, the first groove 233 is arranged on the side of the cover body 231 away from the electrode assembly 22 in the first direction X, so that the first groove 233 faces the outside of the battery cell 20, thereby reducing the difficulty of processing the first groove 233 on the cover body 231 of the end cover 23, which is beneficial to improving the manufacturing efficiency of the battery cell 20.

[0194] In some embodiments, reference Fig.10 , Fig.11 , Fig.12 , Fig.13 and Fig.14 , Fig.10 A cross-sectional view of a battery cell 20 provided in some other embodiments of the present application, Fig.11 for Fig.10 The partial enlarged view of the battery cell 20 at C is shown. Fig.12 This is a schematic diagram of the structure of the end cover 23 of the battery cell 20 provided in some other embodiments of the present application. Fig.13 The cross-sectional view of the end cover 23 of the battery cell 20 provided in some other embodiments of the present application is as follows: Fig.14 for Fig.13 The end cap 23 is shown in a partially enlarged view at D. Along the first direction X, the first groove 233 is disposed on a side of the cap body 231 facing the electrode assembly 22 .

[0195] In the embodiment where the first groove 233 is disposed on the groove bottom wall 213 of the third groove 234 , the first groove 233 is disposed on a side of the cover body 231 facing the electrode assembly 22 in the first direction X and corresponding to the area of ​​the third groove 234 .

[0196] In this embodiment, the first groove 233 is arranged on the side of the cover body 231 facing the electrode assembly 22 in the first direction X, so that the first groove 233 faces the interior of the battery cell 20, thereby preventing impurities or particles in the external environment from accumulating in the first groove 233, and reducing the risk of the groove wall of the first groove 233 being exposed to the outside and corroded and oxidized by the external environment.

[0197] According to some embodiments of the present application, see Figure 6 and Fig. 9 as well as Fig.11 and Fig.14 As shown, along the first direction X, a protrusion 2312 is formed on one side of the cover body 231, and the protrusion 2312 and the flange portion 232 are both located on the side of the cover body 231 away from the electrode assembly 22. Along the first direction X, the flange portion 232 has a first end surface 2321 away from the electrode assembly 22, and the protrusion 2312 has a first surface 2312a away from the electrode assembly 22, and the first surface 2312a is farther away from the electrode assembly 22 than the first end surface 2321.

[0198] The flange portion 232 has a first end surface 2321 facing away from the electrode assembly 22 , that is, a surface of the flange portion 232 away from one end of the electrode assembly 22 in the first direction X and facing the outside of the battery cell 20 is the first end surface 2321 .

[0199] The protrusion 2312 has a first surface 2312 a facing away from the electrode assembly 22 , that is, a surface of the protrusion 2312 facing away from the electrode assembly 22 in the first direction X and facing the outside of the battery cell 20 is the first surface 2312 a .

[0200] The first surface 2312a is farther away from the electrode assembly 22 than the first end surface 2321, that is, in the first direction X, the first end surface 2321 is located between the first surface 2312a and the electrode assembly 22, that is, the protrusion 2312 extends beyond the flange portion 232 in the first direction X and is away from one end of the electrode assembly 22.

[0201] In this embodiment, by setting the first surface 2312a of the protruding portion 2312 of the cover body 231 away from the electrode assembly 22 in the first direction X to be farther away from the electrode assembly 22 than the first end surface 2321 of the flange portion 232 away from the electrode assembly 22 in the first direction X, on the one hand, the flange portion 232 can be protected to a certain extent through the support and blocking of the first surface 2312a, so as to alleviate the wear of the flange portion 232, thereby improving the assembly effect between the flange portion 232 and the shell 21; on the other hand, the influence of the flange portion 232 protruding from the cover body 231 on the height dimension of the battery cell 20 in the first direction X can be reduced, which is beneficial to reducing the difficulty of subsequent assembly of the battery cell 20 and reducing the interference of the flange portion 232 during the subsequent assembly of the battery cell 20.

[0202] According to some embodiments of the present application, see Figure 6 and Fig. 9 As shown, along the first direction X, the distance between the first surface 2312a and the first end surface 2321 is L, satisfying 0.1 mm≤L≤0.6 mm.

[0203] Among them, the distance L between the first surface 2312a and the first end face 2321 is the distance that the first surface 2312a is farther away from the electrode assembly 22 than the first end face 2321 in the first direction X, and is also the dimension of the protrusion 2312 in the first direction X that exceeds the flange portion 232 and is away from the electrode assembly 22.

[0204] Exemplarily, along the first direction X, the distance L between the first surface 2312a and the first end surface 2321 can be 0.1mm, 0.11mm, 0.12mm, 0.15mm, 0.18mm, 0.2mm, 0.22mm, 0.25mm, 0.28mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.55mm or 0.6mm, etc.

[0205] In this embodiment, the distance between the first surface 2312a of the protruding portion 2312 and the first end surface 2321 of the flange portion 232 is 0.1 mm to 0.6 mm. On the one hand, by setting the spacing between the first surface 2312a and the first end surface 2321 to be greater than or equal to 0.1 mm, the distance between the first surface 2312a and the first end surface 2321 is increased, which is conducive to improving the protective effect of the first surface 2312a on the flange portion 232, so as to alleviate the wear of the flange portion 232, and can further reduce the influence of the flange portion 232 on the height dimension of the battery cell 20 in the first direction X. , so as to reduce the difficulty of subsequent assembly of the battery cells 20 and the risk of interference caused by the flange portion 232 during the subsequent assembly of the battery cells 20. On the other hand, by setting the distance between the first surface 2312a and the first end face 2321 to be less than or equal to 0.6 mm, the phenomenon that the first surface 2312a of the protrusion 2312 is too far away from the first end face 2321 from the electrode assembly 22 is alleviated, which is beneficial to reduce the difficulty of forming the protrusion 2312 on the cover body 231 of the end cover 23, and can save the space occupied by the battery cells 20 in the first direction X, so as to improve the space utilization rate of the battery cells 20.

[0206] According to some embodiments of this application, see Figure 6 and Figure 8 as well as Fig.11 and Fig.13 As shown, along the first direction X, a second groove 2313 is formed on a side of the cover body 231 away from the protruding portion 2312 and at a position corresponding to the protruding portion 2312 .

[0207] Exemplarily, the protrusion 2312 disposed on the side of the cover body 231 away from the electrode assembly 22 is formed by a stamping process, so as to form the protrusion 2312 on the side of the cover body 231 away from the electrode assembly 22, and form a second groove 2313 on the side of the cover body 231 facing the electrode assembly 22 and corresponding to the protrusion 2312. Of course, the processing method of the protrusion 2312 disposed on the side of the cover body 231 away from the electrode assembly 22 is not limited to this. In other embodiments, the protrusion 2312 disposed on the side of the cover body 231 away from the electrode assembly 22 can also be formed by a processing process such as casting or milling.

[0208] In this embodiment, a second groove 2313 is formed on the side of the cover body 231 facing the electrode assembly 22 and in the area corresponding to the protrusion 2312, so that the protrusion 2312 of the cover body 231 is a structure that can be formed by stamping, so that the protrusion 2312 and the second groove 2313 are respectively formed on both sides of the cover body 231 of the end cover 23 along the first direction X, which is beneficial to reduce the manufacturing difficulty of the end cover 23 and improve the processing efficiency of the end cover 23.

[0209] According to some embodiments of the present application, see Figure 8 and Fig.13 As shown, along the first direction X, the second groove 2313 has a second groove bottom surface 2313a facing the electrode assembly 22, the second groove bottom surface 2313a and the first surface 2312a are respectively located on both sides of the cover body 231, and the second groove bottom surface 2313a is protruding with a reinforcing rib 2314.

[0210] Among them, the second groove bottom surface 2313a and the first surface 2312a are respectively located on both sides of the cover body 231, that is, the surface of the groove bottom wall 213 of the second groove 2313 facing the electrode assembly 22 on the first direction X is the second groove bottom surface 2313a, and the surface of the groove bottom wall 213 of the second groove 2313 facing away from the electrode assembly 22 on the first direction X is the first surface 2312a.

[0211] Optionally, the number of reinforcing ribs 2314 protruding from the second groove bottom surface 2313a may be one or more. For example, in the embodiment of the present application, six reinforcing ribs 2314 are protruding from the second groove bottom surface 2313a. The six reinforcing ribs 2314 are arranged at intervals along the circumference of the protruding portion 2312, and each reinforcing rib 2314 is a strip structure extending along the radial direction of the protruding portion 2312. Of course, in other embodiments, the number of reinforcing ribs 2314 protruding from the second groove bottom surface 2313a may also be two, three, four, five or seven, etc.

[0212] It should be noted that, in other embodiments, the reinforcing rib 2314 may also be a structure protruding from the first surface 2312a.

[0213] In this embodiment, by protruding a reinforcing rib 2314 on the second groove bottom surface 2313a of the second groove 2313, the structural strength of the area of ​​the protruding portion 2312 corresponding to the second groove 2313 can be improved, so as to improve the anti-deformation ability of the area of ​​the protruding portion 2312 corresponding to the second groove 2313, and further effectively improve the supporting effect of the first surface 2312a of the protruding portion 2312. In addition, by arranging the reinforcing rib 2314 on the second groove bottom surface 2313a of the second groove 2313, the reinforcing rib 2314 is a structure arranged facing the inside of the battery cell 20, so that the reinforcing rib 2314 can be alleviated from being worn by colliding with external components during use, which is conducive to improving the service life of the reinforcing rib 2314, and can reduce the influence of the reinforcing rib 2314 on the height dimension of the battery cell 20 in the first direction X, which is conducive to reducing the difficulty of subsequent assembly of the battery cell 20 and the interference risk caused by the reinforcing rib 2314 during the subsequent assembly of the battery cell 20.

[0214] In some embodiments, see Figure 7 and Figure 8 as well as Fig.12 and Fig.13 As shown, along the first direction X, a fourth groove 2312 b is formed on the first surface 2312 a at a position corresponding to the reinforcing rib 2314 .

[0215] In the embodiment where the number of reinforcing ribs 2314 protruding from the second groove bottom surface 2313a is multiple, a plurality of fourth grooves 2312b are formed on the first surface 2312a, and each fourth groove 2312b is correspondingly arranged with a reinforcing rib 2314. Figure 7 and Fig.12 In the figure, six reinforcing ribs 2314 are arranged on the bottom surface 2313a of the second groove, and the six reinforcing ribs 2314 are arranged at intervals along the circumference of the protrusion 2312, and each reinforcing rib 2314 is a strip structure extending radially along the protrusion 2312. Correspondingly, six fourth grooves 2312b are formed on the first surface 2312a, and the six fourth grooves 2312b are arranged at intervals along the circumference of the protrusion 2312, and each fourth groove 2312b is a strip structure extending radially along the protrusion 2312.

[0216] Exemplarily, the reinforcing rib 2314 protruding from the second groove bottom surface 2313a is formed by a stamping process to form the reinforcing rib 2314 on the second groove bottom surface 2313a, and a fourth groove 2312b is formed on the first surface 2312a at a position corresponding to the reinforcing rib 2314. Of course, the processing method of the reinforcing rib 2314 protruding from the second groove bottom surface 2313a is not limited to this. In other embodiments, the reinforcing rib 2314 protruding from the second groove bottom surface 2313a can also be formed by a processing process such as casting or milling.

[0217] In this embodiment, a fourth groove 2312b is formed in an area of ​​the first surface 2312a corresponding to the reinforcing rib 2314, so that the reinforcing rib 2314 on the second groove bottom surface 2313a of the second groove 2313 is a structure that can be formed by stamping, so as to form the reinforcing rib 2314 on the second groove bottom surface 2313a, and form the fourth groove 2312b on the first surface 2312a, which is beneficial to reduce the manufacturing difficulty of the end cover 23 and improve the processing efficiency of the end cover 23.

[0218] According to some embodiments of the present application, see Figure 6 and Fig.11 As shown, along the first direction X, the flange portion 232 is bent toward a side of the cover body 231 away from the electrode assembly 22 .

[0219] It should be noted that, in other embodiments, the flange portion 232 may also be bent toward the side of the cover body 231 facing the electrode assembly 22 .

[0220] In this embodiment, by setting the flange portion 232 to a structure that is bent toward the side of the cover body 231 away from the electrode assembly 22, it is possible to facilitate the flange portion 232 to be inserted into the shell 21 from the opening 211 of the shell 21 and abut against the inner circumferential surface of the shell 21, which is beneficial to reducing the difficulty of assembly between the end cover 23 and the shell 21 and can alleviate the phenomenon of the flange portion 232 being stuck with one end of the shell 21 during the process of being inserted into the shell 21.

[0221] According to some embodiments of the present application, see Figure 6 and Fig. 9 as well as Fig.11 and Fig.14 As shown, the flange portion 232 has a first outer peripheral surface 2322 abutting against the inner peripheral surface of the shell 21. Along the first direction X, the flange portion 232 has a first end surface 2321 facing away from the electrode assembly 22. The first end surface 2321 is connected to the first outer peripheral surface 2322, and the first outer peripheral surface 2322 is welded to the inner peripheral surface of the shell 21.

[0222] The flange portion 232 has a first outer peripheral surface 2322 abutting against the inner peripheral surface of the shell 21 , that is, the surface on the outer peripheral side of the flange portion 232 abutting against the inner peripheral surface of the shell 21 is the first outer peripheral surface 2322 .

[0223] Exemplarily, the first outer circumferential surface 2322 is connected to the inner circumferential surface of the shell 21 by laser welding.

[0224] In this embodiment, by welding the first outer peripheral surface 2322 of the flange portion 232 and the inner peripheral surface of the shell 21 to each other, it is beneficial to further improve the connection reliability and firmness between the flange portion 232 and the shell 21, so as to further improve the assembly effect between the end cover 23 and the shell 21, and can reduce the risk of the end cover 23 and the shell 21 falling off from each other during use.

[0225] In some embodiments, see Figure 6 and Fig. 9 as well as Fig.11 and Fig.14 As shown, the end of the housing 21 forming the opening 211 in the first direction X has a second end surface 215 , and the second end surface 215 is connected to the inner circumference of the housing 21 . Along the first direction X, the second end surface 215 is coplanar with the first end surface 2321 .

[0226] Among them, the end of the shell 21 forming the opening 211 in the first direction X has a second end surface 215, that is, the end surface of the shell 21 forming the opening 211 is the second end surface 215, that is, the opening 211 is arranged on the second end surface 215 so that the second end surface 215 is connected to the inner circumferential surface of the shell 21.

[0227] In the embodiment where the housing 21 includes a bottom wall 213 and a side wall 214 , the second end surface 215 is an end surface of the side wall 214 away from the bottom wall 213 in the first direction X, and the opening 211 is formed on the second end surface 215 .

[0228] Exemplarily, the second end surface 215 of the shell 21 and the inner circumferential surface of the shell 21 are perpendicular to each other and connected.

[0229] The second end surface 215 is coplanar with the first end surface 2321, that is, the second end surface 215 of the housing 21 is flush with the first end surface 2321 of the flange portion 232. Exemplarily, the second end surface 215 of the housing 21 is flush with the first end surface 2321 of the flange portion 232 and is perpendicular to the first direction X.

[0230] In this embodiment, the second end face 215 connected to the shell 21 and its inner circumference and the first end face 2321 connected to the flange portion 232 and its first outer circumference 2322 are arranged to be coplanar structures, so that the second end face 215 of the shell 21 and the first end face 2321 of the flange portion 232 are flush with each other, thereby facilitating reducing the difficulty of welding between the first outer circumference 2322 of the flange portion 232 and the inner circumference of the shell 21, and facilitating improving the welding quality between the first outer circumference 2322 of the flange portion 232 and the inner circumference of the shell 21.

[0231] According to some embodiments of the present application, referring to Fig.15 , Fig.16 , Fig.17 , Fig.18 and Fig.19 , Fig.15 A cross-sectional view of a battery cell 20 provided in some further embodiments of the present application, Fig.16 for Fig.15 The partial enlarged view of the battery cell 20 at E shown in FIG. Fig.17 This is a schematic diagram of the structure of the end cover 23 of the battery cell 20 provided in some other embodiments of the present application. Fig.18 A cross-sectional view of an end cover 23 of a battery cell 20 provided in some further embodiments of the present application, Fig.19 for Fig.18 A partial enlarged view of the F portion of the end cap 23 shown. The flange portion 232 includes a first portion 2323 and a second portion 2324 that are connected to each other. The first portion 2323 is connected to the outer edge of the cover body 231, and the first portion 2323 is arranged around the cover body 231. The first portion 2323 has a first outer peripheral surface 2322 that abuts against the inner peripheral surface of the shell 21. The second portion 2324 is connected to an end of the first portion 2323 away from the electrode assembly 22, and the second portion 2324 protrudes from the first outer peripheral surface 2322. Along the first direction X, the end of the shell 21 forming the opening 211 has a second end surface 215, the second end surface 215 is connected to the inner peripheral surface of the shell 21, and the second portion 2324 abuts against the second end surface 215.

[0232] The first portion 2323 has a first outer peripheral surface 2322 abutting against the inner peripheral surface of the shell 21 , that is, the surface where the outer peripheral side of the first portion 2323 of the flange portion 232 abuts against the inner peripheral surface of the shell 21 is the first outer peripheral surface 2322 .

[0233] The second portion 2324 is connected to one end of the first portion 2323 away from the electrode assembly 22, and the second portion 2324 protrudes from the first outer peripheral surface 2322, that is, the second portion 2324 is connected to one end of the first portion 2323 away from the cover body 231 in the first direction X, and the second portion 2324 and the first portion 2323 form an "L"-shaped structure or a "T"-shaped structure. For example, in Fig.19 In the embodiment, the second portion 2324 and the first portion 2323 form an "L" shaped structure.

[0234] Optionally, the first part 2323 and the second part 2324 may be an integrally formed structure, or may be a structure that is separately disposed and connected. For example, in Fig.19 In the embodiment, the first part 2323 and the second part 2324 are an integrally formed structure, and the flange portion 232 is bent to form the first part 2323 and the second part 2324. Of course, in other embodiments, the first part 2323 and the second part 2324 may also be a separate structure, and the second part 2324 may be connected to the first part 2323 by welding or bonding.

[0235] The second portion 2324 abuts against the second end surface 215 . That is, the second portion 2324 abuts against one end of the housing 21 in the first direction X where the opening 211 is formed.

[0236] It should be noted that in the embodiment where the flange portion 232 includes a first portion 2323 and a second portion 2324 , the first end surface 2321 of the flange portion 232 is a surface of the second portion 2324 on a side away from the electrode assembly 22 in the first direction X.

[0237] In this embodiment, the flange portion 232 is provided with a first part 2323 and a second part 2324, the first part 2323 has a first outer peripheral surface 2322 that abuts against the inner peripheral surface of the shell 21, and the second part 2324 is connected to the first part 2323 and protrudes from the first outer peripheral surface 2322 of the first part 2323. By setting the second part 2324 to abut on the second end surface 215 of the shell 21 along the first direction X, the part of the flange portion 232 is a structure overlapped on the end of the shell 21 where the opening 211 is formed along the first direction X, so that the second part 2324 of the flange portion 232 can also play a certain role in limiting and positioning, which is conducive to alleviating the phenomenon that the flange portion 232 of the end cover 23 is transitionally inserted into the shell 21, and is conducive to improving the assembly accuracy and assembly quality between the end cover 23 and the shell 21.

[0238] In some embodiments, see Fig.16 and Fig.19As shown, the second portion 2324 has a second surface 2324 a abutting against the second end surface 215 in the first direction X, and the second surface 2324 a is welded to the second end surface 215 .

[0239] Among them, the second surface 2324a is the surface of the second part 2324 facing the second end face 215 in the first direction X and abutting against each other, that is, the surfaces on both sides of the second part 2324 in the first direction X are the first end face 2321 and the second surface 2324a respectively, and the second surface 2324a abuts against the second end face 215 of the shell 21.

[0240] Exemplarily, the second surface 2324a and the second end surface 215 are parallel to each other, and the second surface 2324a and the second end surface 215 are both perpendicular to the first direction X.

[0241] Exemplarily, the second surface 2324a is connected to the second end surface 215 by laser welding.

[0242] In this embodiment, by welding the second surface 2324a of the second part 2324 and the second end face 215 of the shell 21 to each other, on the one hand, the connection reliability and firmness between the flange portion 232 and the shell 21 can be further improved, so as to further improve the assembly effect between the end cover 23 and the shell 21, and can reduce the risk of the end cover 23 and the shell 21 falling off from each other during use; on the other hand, the welding area between the flange portion 232 and the shell 21 can be away from the gap between the first outer peripheral surface 2322 of the first part 2323 and the inner peripheral surface of the shell 21, thereby alleviating the phenomenon that the light beam or heat generated when the flange portion 232 and the shell 21 are welded to each other directly enters the shell 21 through the gap between the first outer peripheral surface 2322 of the first part 2323 and the inner peripheral surface of the shell 21 and burns the electrode assembly 22, which is beneficial to improving the production quality of the battery cell 20.

[0243] In some embodiments, see Fig.17 As shown, the second portion 2324 is arranged around the first portion 2323. In other words, the second portion 2324 is an annular structure extending along the circumference of the first portion 2323.

[0244] Of course, in other embodiments, the flange portion 232 may also be other structures. For example, a plurality of second portions 2324 are connected to the first portion 2323 of the flange portion 232 , and the plurality of second portions 2324 are arranged at intervals along the circumference of the first portion 2323 .

[0245] In this embodiment, the second part 2324 is set as an annular structure to further enhance the effect of the second part 2324 abutting against the second end face 215 of the shell 21 in the first direction X, thereby achieving the function of limiting and positioning the entire periphery of the end cover 23, which is beneficial to further enhance the limiting and positioning effect of the second part 2324, and further enhance the assembly accuracy and assembly quality between the end cover 23 and the shell 21.

[0246] According to some embodiments of the present application, see Figure 6 and Fig. 9 , Fig.11 and Fig.14 as well as Fig.16 and Fig.19 As shown, the flange portion 232 has a first outer peripheral surface 2322 abutting against the inner peripheral surface of the shell 21, and the cover body 231 has a third surface 2315 facing the electrode assembly 22, the third surface 2315 is perpendicular to the first direction X, and the third surface 2315 is set at an obtuse angle to the first outer peripheral surface 2322.

[0247] Among them, the third surface 2315 is the surface of the cover body 231 on one side facing the electrode assembly 22 in the first direction X. In an embodiment in which a third groove 234 is formed on the end cover 23, the third surface 2315 is the surface of the bottom wall 213 of the third groove 234 facing the electrode assembly 22.

[0248] The third surface 2315 and the first outer peripheral surface 2322 are arranged at an obtuse angle, that is, the angle between the cross section of the third surface 2315 in a plane parallel to the first direction X and the cross section of the first outer peripheral surface 2322 in a plane parallel to the first direction X is greater than 90 degrees and less than 180 degrees, so that the first outer peripheral surface 2322 has an inclined structure.

[0249] It should be noted that in the embodiment where the first groove 233 is disposed on the side of the cover body 231 facing the electrode assembly 22, the first groove 233 is disposed on the third surface 2315 of the cover body 231. In the embodiment where the end cap 23 is connected to the electrode tab 221 through the current collecting member 25, the current collecting member 25 is connected to the third surface 2315 of the cover body 231.

[0250] In this embodiment, the first outer peripheral surface 2322 of the flange portion 232 and the third surface 2315 of the cover body 231 facing the electrode assembly 22 are set to an obtuse angle structure, so that the first outer peripheral surface 2322 of the flange portion 232 is an inclined structure, and the end of the first outer peripheral surface 2322 of the flange portion 232 close to the electrode assembly 22 in the first direction X is farther away from the inner peripheral surface of the shell 21 in the radial direction Y of the end cover than the end of the first outer peripheral surface 2322 of the flange portion 232 far away from the electrode assembly 22 in the first direction X, so that on the one hand, The first outer peripheral surface 2322 of the flange portion 232 can play a certain guiding role when the flange portion 232 is inserted into the shell 21, so that the flange portion 232 is inserted into the shell 21, which is beneficial to reducing the difficulty of assembly between the end cover 23 and the shell 21. On the other hand, it can also achieve a closer fit between the flange portion 232 and the inner peripheral surface of the shell 21, which is beneficial to reducing the size of the gap between the first outer peripheral surface 2322 of the flange portion 232 and the inner peripheral surface of the shell 21, so as to improve the assembly quality between the end cover 23 and the shell 21.

[0251] In some embodiments, the angle between the third surface 2315 and the first outer peripheral surface 2322 is α, which satisfies 90°<α≤93°. That is, the angle between the cross section of the third surface 2315 in a plane parallel to the first direction X and the cross section of the first outer peripheral surface 2322 in a plane parallel to the first direction X is greater than 90 degrees and less than or equal to 93 degrees.

[0252] Exemplarily, the angle between the third surface 2315 and the first outer peripheral surface 2322 may be 90.5°, 91°, 91.5°, 92°, 92.5° or 93°, etc.

[0253] In this embodiment, the angle between the third surface 2315 and the first outer peripheral surface 2322 is greater than 90 degrees and less than or equal to 93 degrees, that is, the inclination angle of the first outer peripheral surface 2322 of the flange portion 232 is less than or equal to 3 degrees, thereby alleviating the phenomenon that the inclination angle of the first outer peripheral surface 2322 of the flange portion 232 is too large, resulting in the flange portion 232 being unable to be assembled into the shell 21 or causing excessive difficulty in assembling the flange portion 232 and the shell 21, and can alleviate the phenomenon that the end cover 23 is excessively deformed when the flange portion 232 is inserted into the shell 21 and abuts against the inner peripheral surface of the shell 21 for assembly.

[0254] According to some embodiments of the present application, see Figure 3 , Figure 4 and Figure 5As shown, the shell 21 includes an integrally formed bottom wall 213 and a side wall 214. The side wall 214 is arranged around the bottom wall 213. Along the first direction X, one end of the side wall 214 is connected to the bottom wall 213, and the other end is enclosed to form an opening 211. The side wall 214 and the bottom wall 213 jointly define a accommodating cavity 212 for accommodating the electrode assembly 22, and the flange portion 232 abuts against the inner circumferential surface of the side wall 214.

[0255] The bottom wall 213 and the side wall 214 of the shell 21 are an integrated structure, and the bottom wall 213 and the side wall 214 of the shell 21 can be made by an integrated molding process such as stamping or casting.

[0256] In this embodiment, the shell 21 includes a bottom wall 213 and a side wall 214. The side wall 214 is arranged on the outside of the bottom wall 213, and one end of the side wall 214 in the first direction X is connected to the bottom wall 213, and the other end is enclosed to form an opening 211, so that the flange portion 232 of the end cover 23 is inserted into the side wall 214 from the opening 211 and abuts against the inner circumferential surface of the side wall 214 to complete the assembly of the battery cell 20. The structure is simple and easy to implement, which is beneficial to reducing the processing difficulty of the shell 21 of the battery cell 20.

[0257] According to some embodiments of the present application, see Figure 6 As shown, the flange portion 232 is interference fit with the inner circumference of the housing 21 .

[0258] In this embodiment, by setting the flange portion 232 as a structure that is interference fit with the inner circumferential surface of the shell 21, the gap size between the flange portion 232 and the inner circumferential surface of the shell 21 can be further reduced after the end cover 23 is deformed along the radial direction Y of the end cover, and the connection reliability between the flange portion 232 and the shell 21 can be further improved, thereby further improving the assembly effect between the end cover 23 and the shell 21, thereby reducing the risk of the end cover 23 and the shell 21 falling off from each other during use.

[0259] According to some embodiments of the present application, see Figure 3 and Figure 4 As shown, the housing 21 is cylindrical, and the central axis of the housing 21 extends along the first direction X.

[0260] The housing 21 is cylindrical, and correspondingly, the end cover 23 of the battery cell 20 is a circular plate-shaped structure.

[0261] The central axis of the housing 21 extends along the first direction X, that is, the housing 21 is a cylindrical structure with a central axis extending along the first direction X.

[0262] It should be noted that, in other embodiments, the shape of the shell 21 may also be cylindrical, rectangular, cube-shaped, or prism-shaped.

[0263] In this embodiment, the housing 21 of the battery cell 20 is set to be cylindrical so as to facilitate processing to form the battery cell 20 with a cylindrical structure, so that the battery cell 20 has the advantages of high capacity, long cycle life, and wide operating environment temperature.

[0264] 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.

[0265] Among them, see Figure 2 As shown, the battery 100 may further include a housing 10 , in which the battery cells 20 are accommodated.

[0266] In some embodiments, the box body 10 may include a first box body 11 and a second box body 12 . The first box body 11 and the second box body 12 cover each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cells 20 .

[0267] 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.

[0268] Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder or a cuboid. Figure 2 In the embodiment, the box body 10 is a rectangular parallelepiped structure.

[0269] Optionally, the number of battery cells 20 disposed in the box body 10 may be one or more. Figure 2 In the embodiment, a plurality of battery cells 20 are arranged in the box 10 of the battery 100, and the plurality of battery cells 20 can be connected in series, in parallel or in a mixed connection. The mixed connection means that the plurality of battery cells 20 are both connected in series and in parallel. The plurality of battery cells 20 can be directly connected in series, in parallel or in a mixed connection, and then the whole formed by the plurality of battery cells 20 is accommodated in the box 10; of course, the battery 100 can also be a battery module formed by first connecting the plurality of battery cells 20 in series, in parallel or in a mixed connection, and then the plurality of battery modules are connected in series, in parallel or in a mixed connection to form a whole, and then accommodated in the box 10.

[0270] The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component, which connects the plurality of battery cells 20 to achieve electrical connection between the plurality of battery cells 20 .

[0271] 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.

[0272] According to some embodiments of the present application, the present application further provides an electrical device, which includes a battery cell 20 according to any of the above schemes, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0273] The electrical device may be any of the aforementioned devices or systems using the battery cell 20 .

[0274] According to some embodiments of the present application, see Figures 3 to 9As shown, the present application provides a battery cell 20, which includes a shell 21, an electrode assembly 22 and an end cap 23. The shell 21 is cylindrical, the central axis of the shell 21 extends along the first direction X, and an opening 211 is formed at one end of the shell 21 in the first direction X. The shell 21 includes a bottom wall 213 and a side wall 214 formed in one piece, the side wall 214 is arranged around the bottom wall 213, along the first direction X, one end of the side wall 214 is connected to the bottom wall 213, and the other end is enclosed to form an opening 211, the side wall 214 and the bottom wall 213 jointly define a housing cavity 212, and the electrode assembly 22 is accommodated in the housing cavity 212. The end cap 23 closes the opening 211. The end cap 23 includes a cap body 231 and a flange portion 232. The flange portion 232 is connected to the outer edge of the cap body 231 and is bent toward the side of the cap body 231 away from the electrode assembly 22 in the first direction X. The flange portion 232 is arranged around the cap body 231. At least part of the flange portion 232 is inserted into the shell 21 along the first direction X, and the flange portion 232 is interference-fitted with the inner circumference of the side wall 214 of the shell 21. A first groove 233 is provided on the side of the cap body 231 away from the electrode assembly 22 in the first direction X. The first groove 233 is an annular groove extending along the circumference of the flange portion 232. The first groove 233 is configured to reduce the extrusion force applied by the flange portion 232 to the inner circumference of the shell 21. Along the first direction X, the minimum residual thickness of the first groove 233 is D, which satisfies 0.1 mm≤D≤0.4 mm. A protrusion 2312 is formed on one side of the cover body 231 away from the electrode assembly 22 in the first direction X, and a second groove 2313 is formed on the other side corresponding to the position of the protrusion 2312. The second groove 2313 has a second groove bottom surface 2313a facing the electrode assembly 22, and a reinforcing rib 2314 is protruded from the second groove bottom surface 2313a. The flange portion 232 surrounds the outer side of the protruding portion 2312, and a third groove 234 is formed between the flange portion 232 and the protruding portion 2312, the third groove 234 includes a first groove bottom surface 2341, a first groove side surface 2342 and a second groove side surface 2343, the first groove bottom surface 2341 connects the first groove side surface 2342 and the second groove side surface 2343, the first groove side surface 2342 is formed on the flange portion 232, the second groove side surface 2343 is formed on the protruding portion 2312, the first groove 233 is arranged on the first groove bottom surface 2341, and the groove wall surface of the first groove 233 connects the first groove side surface 2342 and the first groove bottom surface 2341.Along the first direction X, the flange portion 232 has a first end face 2321 facing away from the electrode assembly 22, the protruding portion 2312 has a first surface 2312a facing away from the electrode assembly 22, the first surface 2312a and the second groove bottom surface 2313a are respectively located on both sides of the cover body 231, and a fourth groove 2312b is formed on the first surface 2312a corresponding to the position of the reinforcing rib 2314, and the first surface 2312a is farther away from the electrode assembly 22 than the first end face 2321, and the distance between the first surface 2312a and the first end face 2321 is L, satisfying 0.1mm≤L≤0.6mm. The flange portion 232 has a first outer peripheral surface 2322 abutting against the inner peripheral surface of the shell 21. Along the first direction X, the flange portion 232 has a first end surface 2321 away from the electrode assembly 22, and the first end surface 2321 is connected to the first outer peripheral surface 2322. The end of the shell 21 forming the opening 211 in the first direction X has a second end surface 215, and the second end surface 215 is connected to the inner peripheral surface of the shell 21. The second end surface 215 is coplanar with the first end surface 2321, and the first outer peripheral surface 2322 is welded to the inner peripheral surface of the shell 21. The cover body 231 has a third surface 2315 facing the electrode assembly 22, the third surface 2315 is perpendicular to the first direction X, and the third surface 2315 and the first outer peripheral surface 2322 are arranged at an obtuse angle. The angle between the third surface 2315 and the first outer peripheral surface 2322 is α, which satisfies 90°<α≤93°.

[0275] Of course, see Figures 10 to 14 As shown, the first groove 233 may also be disposed on the side of the cover body 231 facing the electrode assembly 22 . Correspondingly, the first groove 233 is disposed on the third surface 2315 .

[0276] According to some embodiments of the present application, see Figures 15 to 19As shown, the present application provides a battery cell 20, which includes a shell 21, an electrode assembly 22 and an end cap 23. The shell 21 is cylindrical, the central axis of the shell 21 extends along the first direction X, and an opening 211 is formed at one end of the shell 21 in the first direction X. The shell 21 includes a bottom wall 213 and a side wall 214 formed in one piece, the side wall 214 is arranged around the bottom wall 213, along the first direction X, one end of the side wall 214 is connected to the bottom wall 213, and the other end is enclosed to form an opening 211, the side wall 214 and the bottom wall 213 jointly define a housing cavity 212, and the electrode assembly 22 is accommodated in the housing cavity 212. The end cap 23 closes the opening 211. The end cap 23 includes a cap body 231 and a flange portion 232. The flange portion 232 is connected to the outer edge of the cap body 231 and is bent toward the side of the cap body 231 away from the electrode assembly 22 in the first direction X. The flange portion 232 is arranged around the cap body 231. At least part of the flange portion 232 is inserted into the shell 21 along the first direction X, and the flange portion 232 is interference-fitted with the inner circumference of the side wall 214 of the shell 21. A first groove 233 is provided on the side of the cap body 231 away from the electrode assembly 22 in the first direction X. The first groove 233 is an annular groove extending along the circumference of the flange portion 232. The first groove 233 is configured to reduce the extrusion force applied by the flange portion 232 to the inner circumference of the shell 21. Along the first direction X, the minimum residual thickness of the first groove 233 is D, which satisfies 0.1 mm≤D≤0.4 mm. A protrusion 2312 is formed on one side of the cover body 231 away from the electrode assembly 22 in the first direction X, and a second groove 2313 is formed on the other side corresponding to the position of the protrusion 2312. The second groove 2313 has a second groove bottom surface 2313a facing the electrode assembly 22, and a reinforcing rib 2314 is protruded from the second groove bottom surface 2313a. The flange portion 232 surrounds the outer side of the protruding portion 2312, and a third groove 234 is formed between the flange portion 232 and the protruding portion 2312, the third groove 234 includes a first groove bottom surface 2341, a first groove side surface 2342 and a second groove side surface 2343, the first groove bottom surface 2341 connects the first groove side surface 2342 and the second groove side surface 2343, the first groove side surface 2342 is formed on the flange portion 232, the second groove side surface 2343 is formed on the protruding portion 2312, the first groove 233 is arranged on the first groove bottom surface 2341, and the groove wall surface of the first groove 233 connects the first groove side surface 2342 and the first groove bottom surface 2341.Along the first direction X, the flange portion 232 has a first end face 2321 facing away from the electrode assembly 22, the protruding portion 2312 has a first surface 2312a facing away from the electrode assembly 22, the first surface 2312a and the second groove bottom surface 2313a are respectively located on both sides of the cover body 231, and a fourth groove 2312b is formed on the first surface 2312a corresponding to the position of the reinforcing rib 2314, and the first surface 2312a is farther away from the electrode assembly 22 than the first end face 2321, and the distance between the first surface 2312a and the first end face 2321 is L, satisfying 0.1mm≤L≤0.6mm. The flange portion 232 includes an integrally formed first portion 2323 and a second portion 2324, wherein the first portion 2323 is connected to the outer edge of the cover body 231, the first portion 2323 is disposed around the cover body 231, the first portion 2323 has a first outer peripheral surface 2322 abutting against the inner peripheral surface of the shell 21, the second portion 2324 is connected to an end of the first portion 2323 away from the electrode assembly 22, and the second portion 2324 protrudes from the first outer peripheral surface 2322, and the second portion 2324 is an annular structure extending along the circumference of the first portion 2323. Along the first direction X, the end of the shell 21 forming the opening 211 has a second end surface 215, the second end surface 215 is connected to the inner peripheral surface of the shell 21, and the second portion 2324 has a second surface 2324a abutting against the second end surface 215 in the first direction X, and the second surface 2324a is welded to the second end surface 215. The cover body 231 has a third surface 2315 facing the electrode assembly 22 , the third surface 2315 is perpendicular to the first direction X, the third surface 2315 and the first peripheral surface 2322 are arranged at an obtuse angle, and the angle between the third surface 2315 and the first peripheral surface 2322 is α, satisfying 90°<α≤93°.

[0277] 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.

[0278] 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: The housing has an opening formed at at least one end in the first direction; an electrode assembly, contained in the housing; an end cover, closing the opening, the end cover comprising a cover body and a flange portion, the flange portion being connected to an outer edge of the cover body and bent toward one side of the cover body in the first direction, the flange portion being arranged around the cover body, at least a portion of the flange portion being inserted into the shell along the first direction, and the flange portion being in contact with an inner peripheral surface of the shell; Wherein, a first groove is provided on the end cover, and the first groove is configured to reduce the extrusion force applied by the flange portion to the inner circumferential surface of the shell.

2. The battery cell according to claim 1, characterized in that: The first groove is an annular groove extending along the circumference of the flange portion.

3. The battery cell according to claim 1, characterized in that: The first groove is disposed on the cover body.

4. The battery cell according to claim 3, characterized in that: Along the first direction, a protrusion is formed on one side of the cover body, and a second groove is formed on the other side corresponding to the position of the protrusion; Among them, along the first direction, the flange portion and the protruding portion are located on the same side of the cover body, the flange portion surrounds the outer side of the protruding portion, and a third groove is formed between the flange portion and the protruding portion, and the first groove is arranged on the bottom wall of the third groove.

5. The battery cell according to claim 4, characterized in that: The first groove is arranged on a side of the groove bottom wall of the third groove away from the electrode assembly, the third groove comprises a first groove bottom surface, a first groove side surface and a second groove side surface, the first groove bottom surface connects the first groove side surface and the second groove side surface, the first groove side surface is formed at the flange portion, and the second groove side surface is formed at the protruding portion; Wherein, a groove wall surface of the first groove connects the first groove side surface and the first groove bottom surface.

6. The battery cell according to claim 3, characterized in that: Along the first direction, the minimum residual thickness of the first groove is D, satisfying 0.1 mm≤D≤0.4 mm.

7. The battery cell according to claim 3, characterized in that: Along the first direction, the first groove is disposed on a side of the cover body away from the electrode assembly.

8. The battery cell according to claim 3, characterized in that: Along the first direction, the first groove is disposed on a side of the cover body facing the electrode assembly.

9. The battery cell according to claim 1, characterized in that: A protrusion is formed on one side of the cover body along the first direction, and the protrusion and the flange are both located on a side of the cover body away from the electrode assembly; Wherein, along the first direction, the flange portion has a first end surface facing away from the electrode assembly, and the protruding portion has a first surface facing away from the electrode assembly, and the first surface is farther away from the electrode assembly than the first end surface.

10. The battery cell according to claim 9, characterized in that: Along the first direction, a distance L between the first surface and the first end surface satisfies 0.1 mm≤L≤0.6 mm.

11. The battery cell according to claim 9, characterized in that: Along the first direction, a second groove is formed on a side of the cover body away from the protruding portion and corresponding to a position of the protruding portion.

12. The battery cell according to claim 11, characterized in that: Along the first direction, the second groove has a second groove bottom surface facing the electrode assembly, the second groove bottom surface and the first surface are respectively located on two sides of the cover body, and the second groove bottom surface is protrudingly provided with reinforcing ribs.

13. The battery cell according to claim 12, characterized in that: A fourth groove is formed on the first surface at a position corresponding to the reinforcing rib along the first direction.

14. The battery cell according to any one of claims 1 to 13, characterized in that: Along the first direction, the flange portion is bent toward a side of the cover body away from the electrode assembly.

15. The battery cell according to claim 14, characterized in that: The flange portion has a first outer peripheral surface abutting against the inner peripheral surface of the shell, and along the first direction, the flange portion has a first end surface away from the electrode assembly, and the first end surface is connected to the first outer peripheral surface; Wherein, the first outer peripheral surface is welded to the inner peripheral surface of the shell.

16. The battery cell according to claim 15, characterized in that: One end of the shell forming the opening in the first direction has a second end surface, and the second end surface is connected to the inner peripheral surface of the shell; Wherein, along the first direction, the second end surface is coplanar with the first end surface.

17. The battery cell according to claim 14, characterized in that: The flange portion comprises: A first portion connected to an outer edge of the cover body, the first portion is disposed around the cover body, and the first portion has a first outer peripheral surface abutting against an inner peripheral surface of the shell; A second portion connected to an end of the first portion away from the electrode assembly, and the second portion protrudes from the first outer peripheral surface; Wherein, along the first direction, one end of the shell forming the opening has a second end surface, the second end surface is connected to the inner circumferential surface of the shell, and the second part abuts against the second end surface.

18. The battery cell according to claim 17, characterized in that: The second portion has a second surface abutting against the second end surface in the first direction, and the second surface is connected to the second end surface by welding.

19. The battery cell according to claim 17, characterized in that: The second portion is disposed around the first portion.

20. The battery cell according to claim 14, characterized in that: The flange portion has a first outer peripheral surface abutting against the inner peripheral surface of the shell, and the cover body has a third surface facing the electrode assembly, the third surface is perpendicular to the first direction, and the third surface is arranged at an obtuse angle with the first outer peripheral surface.

21. The battery cell according to claim 20, characterized in that: The included angle between the third surface and the first outer peripheral surface is α, which satisfies 90°<α≤93°.

22. The battery cell according to claim 1, characterized in that: The shell comprises an integrally formed bottom wall and side wall, the side wall is arranged around the bottom wall, one end of the side wall is connected to the bottom wall along the first direction, and the other end of the side wall is surrounded to form the opening, and the side wall and the bottom wall together define a receiving cavity for receiving the electrode assembly; Wherein, the flange portion abuts against the inner peripheral surface of the side wall.

23. The battery cell according to claim 1, characterized in that: The flange portion is interference fit with the inner circumferential surface of the shell.

24. The battery cell according to claim 1, characterized in that The shell is cylindrical, and the central axis of the shell extends along the first direction.

25. A battery, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 24.

26. An electrical device, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 24, wherein the battery cell is used to provide electrical energy.

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