Battery monomer, battery and electric device

Abstract

The invention 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 a plugging piece, a containing cavity is formed in the shell, and the shell is provided with a first wall. The electrode assembly is contained in the containing cavity and comprises a main body part and a first electrode leading-out part, the first electrode leading-out part is connected to the end, close to the first wall, of the main body part in the thickness direction of the first wall, and the first electrode leading-out part is connected with the first wall in a welded mode to form a first connecting part. The blocking piece is arranged on the side, away from the electrode assembly, of the first wall, the blocking piece is in sealed connection with the first wall, and the blocking piece covers the first connecting part in the thickness direction of the first wall. According to the invention, the plugging member is arranged on the first wall, so that the plugging member can play a role in sealing the welding connection area of the first wall and the first electrode leading-out part, the first connecting part is arranged in the battery monomer, and the phenomenon of air tightness failure of the battery monomer caused by welding defects and the like can be effectively relieved.

Description

[0001] This application is a divisional application based on the invention with application number 2024110061946, application date July 25, 2024, and invention name “Battery cell, battery and electrical device”. Technical Field

[0002] 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

[0003] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also growing. Among them, the battery usually includes a box and multiple battery cells contained in the box.

[0004] In battery technology, a battery cell includes a shell and an electrode assembly contained in the shell. The electrode assembly is formed with a pole ear, and the pole ear and the shell are interconnected, so that the input or output of electrical energy of the battery cell can be achieved through the shell. However, the shell of the battery cell in the prior art is very prone to airtightness failure, resulting in the risk of gas leakage or liquid leakage during use of the battery cell, which is not conducive to improving the reliability of the battery cell. Summary of the invention

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

[0006] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell, an electrode assembly and a sealing member; a accommodating cavity is formed inside the shell, and the shell has a first wall; the electrode assembly is accommodated in the accommodating cavity, and the electrode assembly comprises a main body and a first electrode lead-out portion, the first electrode lead-out portion is connected to an end of the main body close to the first wall in the thickness direction of the first wall, the first electrode lead-out portion is welded to the first wall and forms a first connection portion; the sealing member is arranged on a side of the first wall away from the electrode assembly, the sealing member is sealed and connected to the first wall, and the sealing member covers the first connection portion along the thickness direction of the first wall.

[0007] In the above technical solution, a sealing member is provided on the side of the first wall of the shell away from the electrode assembly, the sealing member and the first wall are in a sealed connection structure, and the sealing member covers the first connection portion formed by the mutual welding connection of the first electrode lead-out portion and the first wall in the thickness direction of the first wall, so that the sealing member can seal and plug the area where the first wall of the shell and the first electrode lead-out portion of the electrode assembly are welded to each other, so as to realize that the first connection portion formed by the mutual welding connection of the first wall of the shell and the first electrode lead-out portion of the electrode assembly is a structure built into the interior of the battery cell, thereby effectively alleviating the phenomenon of airtightness failure of the battery cell caused by welding defects, welding cracks or welding penetration in the area where the first wall and the first electrode lead-out portion are welded to each other, and further effectively reducing the risk of gas leakage or liquid leakage in the battery cell during use, so as to improve the reliability of the battery cell.

[0008] In some embodiments, the first wall is provided with an exhaust hole communicating with the accommodating cavity, and the exhaust hole penetrates the first wall along the thickness direction of the first wall; wherein the blocking member is configured to discharge the internal pressure of the battery cell.

[0009] In the above technical solution, the sealing member is provided as a pressure relief member for releasing the internal pressure of the battery cell, and an exhaust hole is provided on the first wall which penetrates the first wall and is connected to the accommodating cavity, so that when the battery cell thermally runs away, the exhaust hole can also guide the discharge inside the battery cell to the sealing member for release, so that while the sealing member seals the first connection part to reduce the risk of airtight failure of the battery cell, the internal pressure of the battery cell can be released through the sealing member, so that the sealing member can not only realize the first connection part being built into the interior of the battery cell, but also play a pressure relief role when the battery cell thermally runs away, thereby optimizing the structure of the battery cell and reducing the manufacturing cost of the battery cell.

[0010] In some embodiments, the blocking member and the first wall together define an exhaust cavity, and the exhaust hole communicates with the exhaust cavity and the accommodating cavity.

[0011] In the above technical solution, an exhaust cavity is formed between the sealing member and the first wall, and the exhaust cavity is connected with the accommodating cavity inside the shell through the exhaust hole, so that the emissions generated when the battery cell thermal runaway can enter the exhaust cavity through the exhaust hole and then be discharged through the sealing member. The battery cell adopting this structure can, on the one hand, play a certain buffering role for the emissions generated when the battery cell thermal runaway through the exhaust cavity, which is beneficial to alleviate the phenomenon of emissions accumulation in the accommodating cavity. On the other hand, it can alleviate the phenomenon that the sealing member only partially contacts the emissions discharged from the exhaust hole, which is beneficial to increase the contact area between the emissions and the sealing member, thereby improving the timeliness and rate of pressure relief of the battery cell.

[0012] In some embodiments, along the thickness direction of the first wall, the sealing member has a first surface facing the electrode assembly, and the first surface abuts against the first wall; wherein the first surface is provided with a first groove, and the groove wall surface of the first groove and the first wall jointly define the exhaust cavity.

[0013] In the above technical solution, the sealing member has a first surface facing the electrode assembly and abutting against the first wall in the thickness direction of the first wall, and a first groove is arranged on the first surface, so that the groove wall surface of the first groove and the first wall together define an exhaust cavity connected to the exhaust hole. The battery cell adopting this structure can reduce the difficulty of assembling the sealing member and the first wall, and can reduce the difficulty of forming the exhaust cavity between the sealing member and the first wall. The structure is simple and easy to implement and assemble.

[0014] In some embodiments, along the thickness direction of the first wall, the sealing member has a second surface facing away from the electrode assembly, and a first protrusion is formed on a side of the sealing member facing away from the electrode assembly and corresponding to the position of the first groove, and the first protrusion protrudes from the second surface.

[0015] In the above technical solution, a first protrusion protruding from the second surface is formed on the side of the sealing member away from the electrode assembly and at a position corresponding to the first groove, so that the first groove on the first surface of the sealing member is a structure that can be formed by a stamping process to form the first groove and the first protrusion on both sides of the sealing member respectively, thereby effectively reducing the difficulty of forming the sealing member and improving the production efficiency of the battery cell.

[0016] In some embodiments, the sealing member is provided with a pressure relief groove, and the sealing member is configured to be able to split along at least a portion of the pressure relief groove when the battery cell is depressurized to release the internal pressure of the battery cell; wherein, along the thickness direction of the first wall, the projection of the pressure relief groove is located within the first groove.

[0017] In the above technical solution, a pressure relief groove for pressure relief is provided on the sealing member, so that when the battery cell thermal runaways, the sealing member can release the internal pressure of the battery cell after being broken along at least part of the pressure relief groove, so as to realize the function of the sealing member to release the internal pressure of the battery cell. The structure is simple and easy to realize. Specifically, by setting the pressure relief groove of the sealing member to a structure in which the projection in the thickness direction of the first wall is located within the first groove, the sealing member can be broken in the area where the exhaust cavity is formed and release the emissions inside the battery cell, thereby improving the convenience and smoothness of the sealing member in releasing the internal pressure of the battery cell, so as to improve the timeliness and rate of pressure relief of the battery cell.

[0018] In some embodiments, along the thickness direction of the first wall, the pressure relief groove is arranged on a side of the sealing member away from the electrode assembly.

[0019] In the above technical solution, the pressure relief groove is arranged on the side of the sealing member away from the electrode assembly in the thickness direction of the first wall so as to facilitate the formation of the pressure relief groove on the sealing member, which helps to reduce the difficulty of processing the sealing member.

[0020] In some embodiments, the first electrode lead-out portion includes a first electrode tab and a first current collecting member, wherein the first electrode tab is connected to one end of the main body portion close to the first wall along the thickness direction of the first wall, and the first current collecting member is disposed between the first electrode tab and the first wall, the first current collecting member is connected to the first electrode tab, and the first current collecting member is welded to the first wall to form the first connecting portion; wherein a through hole is disposed on the first current collecting member, the through hole passes through both sides of the first current collecting member along the thickness direction of the first wall, and the through hole is connected to the exhaust hole.

[0021] In the above technical solution, the first electrode lead-out portion is provided with a first electrode ear and a first current collecting member, and the first current collecting member connects the first electrode ear and the first wall, so that the first electrode ear of the electrode assembly is a structure welded to the first wall through the first current collecting member, thereby reducing the difficulty of mutual electrical connection between the electrode assembly and the first wall, and reducing the difficulty of welding between the first electrode lead-out portion and the first wall, which is beneficial to improving the assembly efficiency of the battery cell, wherein, by providing a through hole penetrating the first current collecting member along the thickness direction of the first wall on the first current collecting member, and the through hole is interconnected with the exhaust hole on the first wall, when thermal runaway occurs in the battery cell, the exhaust inside the electrode assembly can enter the exhaust hole of the first wall through the through hole of the first current collecting member and then be discharged through the sealing member, thereby effectively improving the exhaust smoothness inside the battery cell to improve the pressure relief rate of the battery cell.

[0022] In some embodiments, along the thickness direction of the first wall, at least a portion of a projection of at least one of the through holes is located within one of the exhaust holes.

[0023] In the above technical solution, by setting at least a portion of the projection of at least one through hole on the first current collecting member in the thickness direction of the first wall to be located in an exhaust hole, so that the through hole can guide the emissions in the accommodating cavity to the exhaust hole, the smoothness of the emissions inside the battery cell entering the exhaust hole through the through hole can be effectively improved, so as to further improve the exhaust smoothness inside the battery cell, and then the timeliness and rate of pressure relief of the battery cell can be further improved.

[0024] In some embodiments, the first electrode lead-out portion includes a first electrode tab and a first current collecting member, and along the thickness direction of the first wall, the first electrode tab is connected to one end of the main body portion close to the first wall, and the first current collecting member is arranged between the first electrode tab and the first wall, and the first current collecting member is connected to the first electrode tab, and the first current collecting member is welded to the first wall to form the first connection portion; wherein, along the thickness direction of the first wall, the first wall has a third surface facing the electrode assembly, and the first wall has a protrusion protruding from the third surface, the protrusion is welded to the first current collecting member to form the first connection portion, and an exhaust gap is formed between the first current collecting member and the third surface, and the exhaust gap is connected to the exhaust hole.

[0025] In the above technical solution, the first electrode lead-out portion is provided with a first pole ear and a first current collecting member, and the first current collecting member connects the first pole ear and the first wall, so that the first pole ear of the electrode assembly is a structure welded to the first wall through the first current collecting member, thereby reducing the difficulty of electrical connection between the electrode assembly and the first wall, and reducing the difficulty of welding between the first electrode lead-out portion and the first wall, which is beneficial to improving the assembly efficiency of the battery cell, wherein, by providing a protrusion welded to the first current collecting member on the third surface of the first wall facing the electrode assembly, and the protrusion protrudes from the third surface, so as to form an exhaust gap connected to the exhaust hole between the first current collecting member and the third surface of the first wall, so that the emissions generated by the battery cell during thermal runaway can enter the exhaust hole of the first wall through the exhaust gap and then be discharged through the sealing member, thereby effectively improving the exhaust smoothness inside the battery cell, so as to improve the timeliness and rate of pressure relief of the battery cell.

[0026] In some embodiments, the shell is cylindrical, and the central axis of the shell extends along the thickness direction of the first wall; wherein, a plurality of the exhaust holes are arranged on the first wall, the plurality of the exhaust holes include a plurality of first exhaust holes, and the plurality of the first exhaust holes are arranged at intervals around the central axis of the shell.

[0027] In the above technical solution, the outer shell of the battery cell is cylindrical, and the central axis of the outer shell extends along the thickness direction of the first wall. By arranging a plurality of first exhaust holes on the first wall, and the plurality of first exhaust holes are arranged at intervals around the central axis of the outer shell, the exhaust area and exhaust region of the exhaust holes through which the emissions generated by the battery cell during thermal runaway are guided to the sealing member can be increased, thereby effectively improving the rate at which the exhaust holes guide the emissions in the accommodating cavity to the sealing member, thereby improving the timeliness and rate of pressure relief of the battery cell.

[0028] In some embodiments, a projection of the first exhaust hole in the thickness direction of the first wall is in a sector ring shape extending along the circumference of the housing.

[0029] In the above technical solution, by setting the shape of the first exhaust hole to a fan-shaped ring extending along the circumference of the shell, on the one hand, it is convenient to form a plurality of first exhaust holes on the first wall that are spaced apart around the central axis of the shell, which is conducive to reducing the difficulty of setting a plurality of first exhaust holes on the first wall; on the other hand, it is possible to optimize the layout of the plurality of first exhaust holes on the first wall, and to maximize the exhaust area of ​​the first exhaust hole under the condition of the same area, so as to further improve the rate at which the first exhaust hole guides the discharge in the accommodating cavity to the sealing member.

[0030] In some embodiments, the electrode assembly has a central through hole extending along the thickness direction of the first wall, and the central through hole passes through both ends of the main body in the thickness direction of the first wall; wherein, the plurality of exhaust holes also include a second exhaust hole, and the plurality of first exhaust holes are arranged around the second exhaust hole, and along the thickness direction of the first wall, at least part of the projection of the second exhaust hole is located in the central through hole.

[0031] In the above technical solution, by arranging the second exhaust holes on the first wall, the multiple first exhaust holes are a structure arranged around the second exhaust holes, and at least a part of the projection of the second exhaust holes in the thickness direction of the first wall is located in the central through hole of the electrode assembly. The battery cell adopting such a structure can, on the one hand, further increase the exhaust area of ​​the exhaust holes on the first wall, and can effectively optimize the layout of the first exhaust holes and the second exhaust holes among the multiple exhaust holes, and on the other hand, it can also realize that the emissions generated by the battery cell during thermal runaway enter from the central through hole of the electrode assembly to the second exhaust holes and then pass through the blocking member for discharge, which is conducive to further improving the rate at which the exhaust holes guide the emissions in the accommodating cavity to the blocking member, so as to improve the timeliness and rate of pressure relief of the battery cell.

[0032] In some embodiments, the first electrode lead-out portion includes a first electrode tab and a first current collecting member; the first electrode tab is connected to one end of the main body portion close to the first wall in the thickness direction of the first wall; the first current collecting member is arranged between the first electrode tab and the first wall along the thickness direction of the first wall, the first current collecting member is connected to the first electrode tab, and the first current collecting member is welded to the first wall to form the first connecting portion.

[0033] In the above technical solution, the first electrode lead-out portion is provided with a first pole ear and a first current collecting member, the first pole ear is connected to the main body, and the first current collecting member is connected to the first pole ear and welded to the first wall to form a first connecting portion, so that the first pole ear of the electrode assembly is a structure welded to the first wall through the first current collecting member, thereby reducing the difficulty of electrical connection between the electrode assembly and the first wall, and reducing the difficulty of welding between the first electrode lead-out portion and the first wall, which is beneficial to improving the assembly efficiency of the battery cell.

[0034] In some embodiments, the first current collecting member is connected to the first electrode tab by welding to form a second connection portion.

[0035] In the above technical solution, the first current collecting member and the first pole lug are connected by a welding connection structure, which is conducive to improving the connection stability between the first current collecting member and the first pole lug, so as to reduce the risk of the first current collecting member and the first pole lug being separated from each other during use, thereby improving the reliability and stability of the battery cell.

[0036] In some embodiments, along the thickness direction of the first wall, a projection of the second connecting portion does not overlap with a projection of the first connecting portion.

[0037] In the above technical solution, the first connection portion formed by welding the first current collecting member to the first wall and the second connection portion formed by welding the first current collecting member to the first pole lug are arranged to have non-overlapping projections in the thickness direction of the first wall, thereby reducing the interference between the first connection portion and the second connection portion, and alleviating the overlap of the welding molten pool between the first current collecting member and the first wall and the welding molten pool between the first current collecting member and the first pole lug, thereby facilitating improving the welding quality between the first current collecting member and the first wall and between the first current collecting member and the first pole lug.

[0038] In some embodiments, the first wall is provided with an exhaust hole connected to the accommodating cavity, and the exhaust hole penetrates the first wall along the thickness direction of the first wall; wherein, along the thickness direction of the first wall, a projection of at least one of the second connecting parts is located within one of the exhaust holes.

[0039] In the above technical solution, the first wall is provided with exhaust holes which penetrate through both sides of the first wall along the thickness direction of the first wall, and at least one second connection portion formed by welding the first current collecting member and the first pole ear is arranged so that the projection in the thickness direction of the first wall is located within the exhaust hole. The battery cell adopting such a structure, on the one hand, enables the exhaust hole to play a certain avoidance role for the second connection portion, which is beneficial to reduce the interference between the second connection portion and the first wall, and on the other hand, it can also realize that the electrode assembly is first assembled into the outer shell and then the first current collecting member and the first pole ear are welded and connected from the exhaust hole, so that the welding assembly between the first current collecting member and the first pole ear will not be limited by the assembly order of the electrode assembly and the outer shell, thereby optimizing the assembly process of the battery cell, and after the first current collecting member and the first pole ear are welded and connected from the exhaust hole, the first current collecting member and the first wall can also be welded and connected, which is beneficial to improving the assembly efficiency of the battery cell.

[0040] In some embodiments, the first current collecting member is welded to the first wall to form a plurality of first connection portions, and the first current collecting member is welded to the first electrode tab to form a plurality of second connection portions; wherein the plurality of first connection portions and the plurality of second connection portions are alternately and spaced apart along the circumference of the first current collecting member.

[0041] In the above technical solution, by welding the first current collecting member and the first wall to form a plurality of first connection parts, it is beneficial to further improve the connection reliability between the first current collecting member and the first wall. Similarly, by welding the first current collecting member and the first pole tab to form a plurality of second connection parts, it is beneficial to further improve the connection reliability between the first current collecting member and the first pole tab. Among them, by arranging the plurality of first connection parts and the plurality of second connection parts as a structure alternately and spacedly arranged along the circumference of the first current collecting member, on the one hand, the interference between the first connection part and the second connection part can be reduced to alleviate the phenomenon that the welding molten pool between the first current collecting member and the first wall and the welding molten pool between the first current collecting member and the first pole tab overlap with each other, which is beneficial to improve the welding quality between the first current collecting member and the first wall and between the first current collecting member and the first pole tab. On the other hand, it is beneficial to improve the balance of current flow between the first pole tab and the first current collecting member and between the first current collecting member and the first pole tab, which is beneficial to improve the current passing capacity and current passing effect between the first pole tab and the first current collecting member and between the first current collecting member and the first wall.

[0042] In some embodiments, the first pole lug is a cylindrical structure with a central axis extending along the thickness direction of the first wall, and the second connecting portion extends along the radial direction of the first pole lug; wherein, along the radial direction of the first pole lug, the size of the first pole lug is L1, the size of the second connecting portion is L2, and 0.5≤L2 / L1≤1.

[0043] In the above technical solution, by setting the radial dimension of the second connecting portion of the first pole ear to be larger than half or more than half of the radial dimension of the first pole ear, each circle of the first pole ear from the inside to the outside can form a welding relationship with the first current collecting member, thereby shortening the internal current flow path of the electrode assembly and improving the internal current flow effect of the electrode assembly, so as to reduce the internal resistance of the electrode assembly during use, which is beneficial to improving the performance and stability of the battery cell.

[0044] In some embodiments, along the thickness direction of the first wall, the first wall has a fourth surface facing away from the electrode assembly, and the fourth surface is the surface of the first wall farthest from the electrode assembly; wherein the fourth surface is provided with an assembly groove, the first electrode lead-out portion is welded and connected to the bottom wall of the assembly groove to form the first connection portion, and at least a portion of the sealing member is disposed in the assembly groove.

[0045] In the above technical solution, an assembly groove is provided on the fourth surface of the first wall on the side away from the electrode assembly, and the bottom wall of the assembly groove is welded and connected to the first electrode lead-out portion to form a first connection portion, and at least a portion of the sealing member in the thickness direction of the first wall is provided in the assembly groove. Thus, on the one hand, it is convenient for the sealing member to cover and seal the first connection portion, which is beneficial to reduce the difficulty of covering and sealing the first connection portion by the sealing member, and can improve the effect of covering and sealing the first connection portion by the sealing member. On the other hand, the assembly groove can also play a certain role in assembly positioning and protection of the sealing member, which can effectively reduce the difficulty of assembly between the sealing member and the first wall, which is beneficial to improve the assembly efficiency of the sealing member and the first wall, and can effectively reduce the wear and bump of the sealing member during use, which is beneficial to improve the service life of the sealing member.

[0046] In some embodiments, along the thickness direction of the first wall, the blocking member does not extend beyond the fourth surface.

[0047] In the above technical solution, by setting the blocking piece so as not to extend beyond the fourth surface in the thickness direction of the first wall, the blocking piece is a structure that is entirely accommodated in the assembly groove in the thickness direction of the first wall, thereby further enhancing the protective effect of the assembly groove on the blocking piece, thereby further reducing the wear and bumping of the blocking piece during use.

[0048] In some embodiments, along the thickness direction of the first wall, the first wall also has a fifth surface facing the electrode assembly, and a second protrusion is formed on the side of the first wall facing the electrode assembly and corresponding to the position of the assembly groove, and the second protrusion is protruding on the fifth surface.

[0049] In the above technical solution, a second protrusion protruding from the fifth surface is formed on the side of the first wall facing the electrode assembly and corresponding to the position of the assembly groove, so that the assembly groove on the fourth surface of the first wall is a structure that can be formed by a stamping process, so as to form an assembly groove and a second protrusion on both sides of the first wall respectively, thereby effectively reducing the difficulty of forming the first wall of the outer shell and improving the production efficiency of the battery cell.

[0050] In some embodiments, the outer peripheral surface of the blocking member is welded to the groove side surface of the assembly groove to form a third connecting portion, and the third connecting portion is an annular structure.

[0051] In the above technical solution, the outer peripheral surface of the sealing piece and the groove side surface of the assembly groove are welded to each other to form a third connecting portion arranged around the sealing piece, so as to realize a sealed connection between the sealing piece and the first wall through the third connecting portion. The battery cell adopting this structure can, on the one hand, improve the connection stability between the sealing piece and the first wall, which is beneficial to reduce the risk of the sealing piece detaching during use, and can reduce the difficulty of the sealing connection between the sealing piece and the first wall, so as to improve the assembly efficiency of the sealing piece and the first wall. On the other hand, the structure of the sealed connection formed by welding the outer peripheral surface of the sealing piece and the groove side surface of the assembly groove can improve the effect of the sealing connection between the sealing piece and the first wall, and can reduce the influence of the third connecting portion on the airtightness of the battery cell.

[0052] In some embodiments, the assembly groove includes a first groove and a second groove, the first groove is arranged on the fourth surface, the second groove is arranged on the bottom surface of the first groove, the first electrode lead-out portion is welded to the bottom wall of the second groove to form the first connection portion; wherein the outer peripheral surface of the sealing member is welded to the side surface of the second groove to form the third connection portion.

[0053] In the above technical scheme, the assembly groove includes a first groove arranged on the fourth surface and a second groove arranged on the groove bottom surface of the first groove, so that the assembly groove is a stepped groove structure arranged along the thickness direction of the first wall, and the groove bottom wall of the second groove is welded to the first electrode lead-out part to form a first connection part, and the outer peripheral surface of the sealing member is welded to the groove side surface of the second groove to form a third connection part of an annular structure, so that on the one hand, it is convenient for the sealing member to cover and seal the first connection part, which is beneficial to reduce the difficulty of covering and sealing the first connection part by the sealing member, and can improve the effect of covering and sealing the first connection part by the sealing member, and on the other hand, the first groove can also accommodate and protect the part of the third connection part protruding from the groove bottom surface of the first groove, which is beneficial to reduce the interference between the third connection part and other components, and is beneficial to reduce the phenomenon of bumps and wear of the third connection part during use.

[0054] In some embodiments, along the thickness direction of the first wall, the third connecting portion does not extend beyond the fourth surface.

[0055] In the above technical solution, by setting the third connecting part to a structure that does not exceed the fourth surface in the thickness direction of the first wall, the part of the third connecting part protruding from the bottom surface of the first groove is a structure that is located as a whole in the first groove, thereby further enhancing the protective effect of the first groove on the third connecting part, which is beneficial to further reduce the interference between the third connecting part and other components, and is beneficial to further reduce the phenomenon of bumps and wear on the third connecting part during use.

[0056] In some embodiments, along the thickness direction of the first wall, the blocking member has a second surface facing away from the electrode assembly, the second surface is connected to the outer peripheral surface of the blocking member, and the second surface is coplanar with the bottom surface of the first groove.

[0057] In the above technical solution, by setting the second surface of the sealing member which is away from the side of the electrode assembly and interconnected with the outer peripheral surface of the sealing member to a structure which is coplanar with the bottom surface of the first groove, the second surface of the sealing member and the bottom surface of the first groove are made to be flush with each other, thereby further improving the welding quality between the outer peripheral surface of the sealing member and the groove side surface of the second groove, thereby improving the assembly quality between the sealing member and the first wall.

[0058] In some embodiments, along the thickness direction of the first wall, the blocking member abuts against the bottom surface of the second groove.

[0059] In the above technical solution, by setting the blocking piece as a structure that abuts against the bottom surface of the second groove in the thickness direction of the first wall, the bottom surface of the second groove can also play a certain supporting and positioning role for the blocking piece. On the one hand, it can further improve the welding quality between the blocking piece and the first wall, which is conducive to further improving the assembly quality and assembly stability of the blocking piece and the first wall. On the other hand, it can further reduce the assembly difficulty between the blocking piece and the first wall, so as to improve the assembly efficiency of the blocking piece and the first wall.

[0060] In some embodiments, a second groove is provided on the bottom surface of the assembly groove, and along the thickness direction of the first wall, the projection of the first connecting portion is located in the second groove.

[0061] In the above technical solution, a second groove is provided on the groove bottom surface of the assembly groove, and the projection of the first connection portion formed by welding the first electrode lead portion to the groove bottom wall of the assembly groove in the thickness direction of the first wall is located within the second groove, so that the first connection portion is a structure formed by welding the groove bottom wall of the second groove to the first electrode lead portion. The battery cell adopting such a structure, on the one hand, facilitates the covering and sealing of the first connection portion by the sealing member, which is conducive to reducing the difficulty of covering and sealing the first connection portion by the sealing member, and can improve the covering and sealing effect of the sealing member on the first connection portion; on the other hand, the part of the first connection portion protruding from the groove bottom surface of the second groove can be accommodated by the second groove, which is conducive to reducing the interference between the first connection portion and the sealing member arranged in the assembly groove.

[0062] In some embodiments, along the thickness direction of the first wall, the blocking member covers the second groove.

[0063] In the above technical solution, the blocking member is arranged to cover the second groove in the thickness direction of the first wall so that the blocking member can cover the first connection portion and the covering and sealing effect of the blocking member on the first connection portion can be improved.

[0064] In some embodiments, along the thickness direction of the first wall, the bottom wall of the assembly groove has a third surface facing the electrode assembly, and a protrusion protruding from the third surface is formed on the side of the bottom wall of the assembly groove facing the electrode assembly and corresponding to the position of the second groove, and the protrusion is welded to the first electrode lead-out portion to form the first connecting portion.

[0065] In the above technical solution, a protrusion protruding from the third surface is formed on the side of the bottom wall of the second groove facing the electrode assembly and corresponding to the position of the second groove, and the protrusion is used to be welded and connected to the first electrode lead-out portion to form a first connection portion. A battery cell adopting such a structure enables the portion of the first wall used for welding and connecting the first electrode lead-out portion to be in full contact with the first electrode lead-out portion, which is beneficial to improving the contact effect between the portion of the first wall used for welding and connecting the first electrode lead-out portion and the first electrode lead-out portion, thereby reducing the difficulty of welding between the first wall and the first electrode lead-out portion on the one hand, and effectively reducing the phenomenon of cold welding when welding and assembling the first wall and the first electrode lead-out portion on the other hand, so as to improve the welding quality between the first wall and the first electrode lead-out portion.

[0066] In some embodiments, the shell includes a shell and an end cover; the shell includes an integrally formed side wall and a bottom wall, the side wall is arranged around the bottom wall, along the thickness direction of the first wall, one end of the side wall is connected to the bottom wall, and the other end is enclosed to form an opening, the side wall and the bottom wall jointly define the accommodating cavity; the end cover closes the opening; wherein the bottom wall is the first wall.

[0067] In the above technical solution, by setting the first wall of the outer shell as the bottom wall of the shell arranged opposite to the end cover in the thickness direction of the first wall, the battery cell adopting this structure can make the first wall which is welded to the first electrode lead-out portion and forms the first connection portion away from the end cover, so that there is no direct connection relationship between the first wall and the end cover, thereby alleviating the influence of the stress generated when the end cover and the shell are assembled and connected to each other on the first connection portion, which is beneficial to improving the welding quality between the first wall and the first electrode lead-out portion, thereby improving the production quality of the battery cell.

[0068] In some embodiments, the shell includes a shell and an end cover; the housing cavity is formed inside the shell, and the housing cavity has an opening formed at one end of the shell; the end cover closes the opening; wherein the end cover is the first wall.

[0069] In the above technical solution, by setting the first wall of the shell as an end cover for closing the opening of the shell, the battery cell adopting this structure is convenient for assembling the sealing part on the end cover, and can reduce the difficulty of welding between the first electrode lead-out portion and the first wall, thereby helping to reduce the difficulty of assembling the battery cell and improving the production efficiency of the battery cell.

[0070] In a second aspect, an embodiment of the present application further provides a battery, comprising the above-mentioned battery cell.

[0071] 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

[0072] 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.

[0073] Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application;

[0074] Figure 2 An exploded view of the structure of a battery provided in some embodiments of the present application;

[0075] Figure 3 A schematic diagram of the structure of a battery cell provided in some embodiments of the present application;

[0076] Figure 4 An exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0077] Figure 5 A cross-sectional view of a battery cell provided for some embodiments of the present application;

[0078] Figure 6 for Figure 5 A partial enlarged view of the battery cell at A shown;

[0079] Figure 7 A partial cross-sectional view of a housing shell provided for some embodiments of the present application;

[0080] Figure 8 A schematic diagram of the structure of a shell of a housing provided in some embodiments of the present application;

[0081] Fig. 9 A front view of a shell of a housing provided for some embodiments of the present application facing the first wall in the thickness direction of the first wall;

[0082] Fig.10 A cross-sectional view of a sealing member of a battery cell provided in some embodiments of the present application;

[0083] Fig.11 A schematic structural diagram of a first current collecting member of a battery cell provided in some embodiments of the present application;

[0084] Fig.12 A schematic diagram of assembling the first wall and the first electrode lead-out portion of a battery cell provided in some embodiments of the present application.

[0085] Icon: 1000-vehicle; 100-battery; 10-box; 11-first box body; 12-second box body; 20-battery monomer; 21-housing; 211-first wall; 2111-exhaust hole; 2111a-first exhaust hole; 2111b-second exhaust hole; 2112-third surface; 2113-protrusion; 2114-fourth surface; 2115-assembly groove; 2115a-first groove; 2115b-second groove; 2116-fifth surface; 2117-second protrusion; 2118-second groove; 212-housing; 2121-accommodation chamber; 2122-opening; 213-end cover; 2131-installation Mounting hole; 22-electrode assembly; 221-main body; 222-first electrode lead-out portion; 2221-first pole ear; 2222-first current collecting member; 2222a-through hole; 2223-second connecting portion; 223-second electrode lead-out portion; 2231-second pole ear; 224-central through hole; 23-sealing member; 231-first surface; 232-first groove; 233-second surface; 234-first protrusion; 235-pressure relief groove; 24-first connecting portion; 25-electrode terminal; 26-exhaust cavity; 27-exhaust gap; 28-third connecting portion; 200-controller; 300-motor; X-thickness direction of the first wall. DETAILED DESCRIPTION

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] The term "plurality" used in the present application refers to two or more (including two).

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.).

[0099] 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 / 3 O2 (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 NCM622 )、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.

[0100] 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.

[0101] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0102] 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.).

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] Among them, the gel electrolyte includes a skeleton network with a polymer as the electrolyte, combined with an ionic liquid-lithium salt.

[0115] Among them, solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0116] 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.

[0117] 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.

[0118] As an example, the composite solid electrolyte is formed by adding an inorganic solid electrolyte filler to a polymer solid electrolyte.

[0119] 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.

[0120] In some embodiments, the electrode assembly is a laminated structure.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0135] 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. In addition, the safety of the battery also needs to be considered.

[0136] For a general battery cell, the battery cell usually includes an outer shell and an electrode assembly contained in the outer shell, and a pole ear is formed on the electrode assembly. The pole ear is welded to a wall of the outer shell, so that the input or output of electrical energy of the battery cell can be realized through the outer shell. In the related art, in order to reduce the difficulty of assembly between the pole ear and the outer shell and the connection stability between the pole ear and the outer shell, a current collecting component is usually provided in the outer shell, and the pole ear and the outer shell are welded and connected by the current collecting component to realize the electrical connection between the pole ear and the outer shell. However, when welding the current collecting component and the outer shell, the battery cell of this structure needs to be penetrated and welded from the outside of the outer shell of the battery cell. The difficulty of penetration welding and the power required are relatively large, so that penetration welding can easily cause welding defects, welding cracks or welding penetration in the welding area between the outer shell and the current collecting component, which can easily lead to problems such as airtight failure of the outer shell, so as to cause the risk of gas leakage or liquid leakage of the battery cell during use, which is not conducive to improving the reliability of the battery cell.

[0137] Based on the above considerations, in order to solve the problem of low reliability of battery cells, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and a plugging member. A housing is formed inside the shell, and the shell has a first wall. The electrode assembly is accommodated in the housing cavity, and the electrode assembly includes a main body and a first electrode lead-out portion, the first electrode lead-out portion is connected to an end of the main body close to the first wall in the thickness direction of the first wall, and the first electrode lead-out portion is welded to the first wall to form a first connection portion. The plugging member is arranged on a side of the first wall away from the electrode assembly, the plugging member is sealed and connected to the first wall, and the plugging member covers the first connection portion along the thickness direction of the first wall.

[0138] In a battery cell of this structure, a sealing piece is provided on the side of the first wall of the shell facing away from the electrode assembly, the sealing piece and the first wall are in a sealed connection, and the sealing piece covers the first connection portion formed by the mutual welding connection of the first electrode lead-out portion and the first wall in the thickness direction of the first wall, so that the sealing piece can seal and plug the area where the first wall of the shell and the first electrode lead-out portion of the electrode assembly are welded to each other, so as to achieve a structure in which the first connection portion formed by the mutual welding connection of the first wall of the shell and the first electrode lead-out portion of the electrode assembly is built into the interior of the battery cell, thereby effectively alleviating the phenomenon of airtightness failure of the battery cell caused by welding defects, welding cracks or welding penetration in the area where the first wall and the first electrode lead-out portion are welded to each other, and further effectively reducing the risk of gas leakage or liquid leakage in the battery cell during use, so as to improve the reliability of the battery cell.

[0139] 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 gas leakage or liquid leakage of the battery cells during use due to failure of the airtightness of the battery cell shell, thereby improving the reliability of the battery cells.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] 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 .

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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 .

[0149] 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.

[0150] 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 partial cross-sectional view of a shell 212 of a shell 21 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 a plugging member 23. An accommodating cavity 2121 is formed inside the shell 21, and the shell 21 has a first wall 211. The electrode assembly 22 is accommodated in the accommodating cavity 2121, and the electrode assembly 22 includes a main body 221 and a first electrode lead-out portion 222. The first electrode lead-out portion 222 is connected to one end of the main body 221 close to the first wall 211 in the thickness direction X of the first wall, and the first electrode lead-out portion 222 is welded to the first wall 211 to form a first connecting portion 24. The plugging member 23 is arranged on the side of the first wall 211 away from the electrode assembly 22, and the plugging member 23 is sealed and connected to the first wall 211, and the plugging member 23 covers the first connecting portion 24 along the thickness direction X of the first wall.

[0151] The housing 21 can also be used to contain electrolyte, such as electrolyte. The housing 21 can be in various structural forms. The housing 21 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0152] In some embodiments, the housing 21 may include a shell 212 and an end cap 213, wherein a accommodating cavity 2121 is formed inside the shell 212, and the accommodating cavity 2121 has an opening 2122, that is, the shell 212 is a hollow structure with one end open, and the end cap 213 covers the opening 2122 of the shell 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte.

[0153] The shell 212 may include a bottom wall and a side wall. The side wall is disposed around the bottom wall. One end of the side wall is connected to the bottom wall, and the other end of the side wall is surrounded to form an opening 2122 .

[0154] Optionally, the first wall 211 of the housing 21 may be an end cover 213 of the housing 21, or may be a bottom wall of a shell 212 of the housing 21. Figure 3 and Figure 4 In the embodiment, the first wall 211 is the bottom wall of the shell 212 disposed opposite to the end cover 213 in the thickness direction X of the first wall. Correspondingly, the thickness direction X of the first wall is the arrangement direction of the end cover 213 and the first wall 211, and is also the thickness direction of the end cover 213. Of course, in other embodiments, the first wall 211 may also be the end cover 213 of the shell 21.

[0155] When assembling the battery cell 20 , the electrode assembly 22 may be placed in the housing 212 first, and the housing 212 may be filled with electrolyte. The end cap 213 may then be placed on the opening 2122 of the housing 212 to seal the opening 2122 of the housing 212 .

[0156] The shell 212 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the shell 212 can be determined according to the specific shape of the electrode assembly 22. For example, if the electrode assembly 22 is a cylindrical structure, the shell 212 can be a cylindrical structure; if the electrode assembly 22 is a cuboid structure, the shell 212 can be a cuboid structure. Of course, the end cap 213 can also be in various structures, such as 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 212 is a cylindrical structure, and correspondingly, the side wall of the shell 212 is also a cylindrical structure, and the central axis of the shell 212 extends along the thickness direction X of the first wall, so that the projection of the first wall 211 in the thickness direction X of the first wall is circular.

[0157] It is understandable that the outer shell 21 is not limited to the above structure, and the outer shell 21 may also be other structures. For example, the outer shell 21 includes a shell 212 and two end covers 213. The shell 212 is a hollow structure with openings 2122 on opposite sides. One end cover 213 corresponds to one opening 2122 of the shell 212 and forms a sealed connection to form a sealed space for accommodating the electrode assembly 22 and the electrolyte. That is, the shell 212 of the outer shell 21 only includes a side wall, and the side wall is a hollow structure with openings 2122 formed at both ends in the thickness direction X of the first wall. The two end covers 213 respectively cover the openings 2122 at both ends of the side wall in the thickness direction X of the first wall.

[0158] It should be noted that the electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. The electrode assembly 22 includes a main body 221 and a first electrode lead-out portion 222. The main body 221 is the main component of the electrode assembly 22 in the battery cell 20 where electrochemical reactions occur, and the first electrode lead-out portion 222 serves to output or input electrical energy from the electrode assembly 22. The structure of the main body 221 of the electrode assembly 22 can be various. For example, the main body 221 of the electrode assembly 22 can be a wound structure formed by winding a positive electrode sheet, a separator, and a negative electrode sheet, or a stacked structure formed by stacking a positive electrode sheet, a separator, and a negative electrode sheet. For example, in Figure 4 In the figure, the main body 221 of the electrode assembly 22 is a wound structure formed by winding the positive electrode sheet, the separator and the negative electrode sheet, and the main body 221 of the electrode assembly 22 is a cylindrical structure, and the central axis of the main body 221 of the electrode assembly 22 extends along the thickness direction X of the first wall.

[0159] 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.

[0160] Optionally, the electrode assembly 22 contained in the housing 21 may be one or more. Figure 4 In the embodiment, only one electrode assembly 22 is disposed in the housing 21 of the battery cell 20. Of course, the structure of the battery cell 20 is not limited thereto. In other embodiments, the number of electrode assemblies 22 contained in the housing 21 may be two, three, four, five, six, seven or eight.

[0161] The first electrode lead-out portion 222 is connected to one end of the main body portion 221 close to the first wall 211 in the thickness direction X of the first wall, that is, the first electrode lead-out portion 222 is located between the main body portion 221 and the first wall 211 in the thickness direction X of the first wall, and the first electrode lead-out portion 222 is connected to the main body portion 221.

[0162] Optionally, the structure of the first electrode lead-out portion 222 can be various. For example, Figure 4 , Figure 5 and Figure 6 In the embodiment, the first electrode lead-out portion 222 includes a first electrode tab 2221 and a first current collecting member 2222. The first electrode tab 2221 is connected to one end of the main body 221 close to the first wall 211 in the thickness direction X of the first wall. The first current collecting member 2222 is arranged between the first electrode tab 2221 and the first wall 211 in the thickness direction X of the first wall. The first current collecting member 2222 is connected to one side of the first electrode tab 2221 facing the first wall 211, and the first current collecting member 2222 is adjacent to the first wall 211. They are welded to each other to form a first connecting portion 24, that is, the first pole ear 2221 of the electrode assembly 22 is a structure that is interconnected with the first wall 211 of the outer shell 21 through the first current collecting component 2222. Of course, in other embodiments, the electrode assembly 22 may not be provided with the first current collecting component 2222, that is, the first electrode lead-out portion 222 is the first pole ear 2221 of the electrode assembly 22, and the first pole ear 2221 is directly welded to the first wall 211 of the outer shell 21 to form a first connecting portion 24.

[0163] Among them, the electrode assembly 22 also includes a second electrode lead-out portion 223, the polarity of the second electrode lead-out portion 223 is opposite to the polarity of the first electrode lead-out portion 222, and the second electrode lead-out portion 223 and the first electrode lead-out portion 222 are respectively used to input or output the positive and negative electrodes of the electrode assembly 22. Of course, the structure of the second electrode lead-out portion 223 of the electrode assembly 22 can also be multiple. For example, the second electrode lead-out portion 223 can be only the second pole ear 2231, and the second electrode lead-out portion 223 can also be the second pole ear 2231 and the second current collecting component, and the second current collecting component is connected to the main body 221 through the second pole ear 2231.

[0164] It should be noted that if the first pole ear 2221 is used for the positive electrode of the output electrode assembly 22, the first pole ear 2221 is a component formed by mutually stacking and connecting the areas on the positive electrode sheet that are not coated with the positive electrode active material layer. Correspondingly, the second pole ear 2231 is used for the negative electrode of the output electrode assembly 22, and the second pole ear 2231 is a component formed by mutually stacking and connecting the areas on the negative electrode sheet that are not coated with the negative electrode active material layer; conversely, if the first pole ear 2221 is used for the negative electrode of the output electrode assembly 22, the first pole ear 2221 is a component formed by mutually stacking and connecting the areas on the negative electrode sheet that are not coated with the negative electrode active material layer. Correspondingly, if the second pole ear 2231 is used for the positive electrode of the output electrode assembly 22, the second pole ear 2231 is a component formed by mutually stacking and connecting the areas on the positive electrode sheet that are not coated with the positive electrode active material layer.

[0165] Exemplarily, the first electrode lead-out portion 222 is arranged at one end of the main body 221 facing the first wall 211 in the thickness direction X of the first wall, and the second electrode lead-out portion 223 is arranged at one end of the main body 221 away from the first wall 211 in the thickness direction X of the first wall, that is, the first electrode lead-out portion 222 and the second electrode lead-out portion 223 are respectively arranged at two ends of the main body 221, and the first electrode lead-out portion 222 is arranged facing the first wall 211.

[0166] In some embodiments, the battery cell 20 may also include an electrode terminal 25, which is insulated and installed on a wall of the outer shell 21 at one end away from the first wall 211 in the thickness direction X of the first wall. The electrode terminal 25 is electrically connected to the second electrode lead-out portion 223, so that the electrode terminal 25 serves as another output pole of the battery cell 20, that is, the electrode terminal 25 can play a role in inputting or outputting electrical energy of the battery cell 20, so that the electrical energy of the battery cell 20 can be coordinated through the electrode terminal 25 and the first wall 211.

[0167] Among them, the electrode terminal 25 is insulated and installed on a wall of the shell 21 at one end away from the first wall 211 in the thickness direction X of the first wall, that is, the electrode terminal 25 is installed on the end of the shell 21 at one end away from the first wall 211 in the thickness direction X of the first wall, and an insulating part is arranged between the electrode terminal 25 and the shell 21, so that no electrical connection is formed between the electrode terminal 25 and the shell 21.

[0168] For example, in Figure 4 and Figure 5 In the embodiment, the first wall 211 is the bottom wall of the housing 212, and correspondingly, the electrode terminal 25 is insulated and mounted on the end cover 213 of the housing 21. Figure 5As shown, the electrode terminal 25 is a structure riveted to the end cap 213, that is, a mounting hole 2131 is provided on the end cap 213, and the hole of the end cap 213 passes through both sides of the end cap 213 along the thickness direction X of the first wall, and a part of the electrode terminal 25 is penetrated in the mounting hole 2131, and the electrode terminal 25 has a first clamping portion located on the side of the end cap 213 facing the electrode assembly 22 and a second clamping portion located on the side of the end cap 213 away from the electrode assembly 22, and at least a part of the end cap 213 is located between the first clamping portion and the second clamping portion in the thickness direction X of the first wall, so that the first clamping portion and the second clamping portion can cooperate to clamp the end cap 213, so as to realize the riveting of the electrode terminal 25 to the first wall 211. Of course, in other embodiments, the electrode terminal 25 can also be a structure clamped or bonded to the end cap 213.

[0169] Exemplarily, the electrode terminal 25 may be made of various materials, for example, the electrode terminal 25 may be made of copper, iron, aluminum, steel, or aluminum alloy.

[0170] It should be noted that, in the embodiment where the second electrode lead-out portion 223 only includes the second pole tab 2231, the second pole tab 2231 of the electrode assembly 22 and the electrode terminal 25 are directly connected, for example, by welding or abutment, etc. In the embodiment where the second electrode lead-out portion 223 includes the second pole tab 2231 and the second current collecting member, the second pole tab 2231 is connected to the main body 221, and the second current collecting member connects the second pole tab 2231 and the electrode terminal 25, so that the second pole tab 2231 is indirectly connected to the electrode terminal 25 through the second current collecting member. Similarly, the connection structure between the second current collecting member and the second pole tab 2231 and between the second current collecting member and the electrode terminal 25 can be various, for example, by welding or abutment, etc.

[0171] For example, in Figure 4 and Figure 5 In the figure, the second electrode lead-out portion 223 is the second electrode tab 2231 of the electrode assembly 22 , that is, the second electrode tab 2231 of the electrode assembly 22 is directly connected to the electrode terminal 25 .

[0172] Exemplarily, the second current collecting member may be made of various materials, for example, the second current collecting member may be made of copper, iron, aluminum, steel or aluminum alloy.

[0173] Of course, the structure of the battery cell 20 is not limited to this. In other embodiments, the battery cell 20 may not be provided with an electrode terminal 25. In an embodiment where the outer shell 21 includes an end cap 213 and a shell 212, and the bottom wall of the shell 212 and the end cap 213 is arranged opposite to each other as the first wall 211, the end cap 213 may also be a structure insulated from the shell 212, that is, an insulating member is arranged between the end cap 213 and the shell 212, so that no electrical connection is formed between the end cap 213 and the shell 212, and correspondingly, the second electrode lead-out portion 223 may be electrically connected to the end cap 213, that is, the end cap 213 can play a role in inputting or outputting electrical energy of the battery cell 20.

[0174] The first electrode lead-out portion 222 is welded to the first wall 211 to form a first connection portion 24 . Correspondingly, the first connection portion 24 is a weld mark formed in a region where the first electrode lead-out portion 222 and the first wall 211 are welded to each other.

[0175] The sealing member 23 is arranged on the side of the first wall 211 away from the electrode assembly 22, and the sealing member 23 is sealed and connected to the first wall 211. That is, the sealing member 23 and the first wall 211 are interconnected and form a sealed structure, so that the space between the sealing member 23 and the first wall 211 is not connected to the outside of the battery cell 20, so that the area where the first connecting portion 24 is located is sealed inside the battery cell 20 by the sealing member 23.

[0176] Exemplarily, the sealing member 23 and the first wall 211 can be sealed with each other by various structures, such as welding or bonding, etc. Similarly, the sealing member 23 can be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0177] The blocking member 23 covers the first connecting portion 24 along the thickness direction X of the first wall, that is, the projection of the first connecting portion 24 in the thickness direction X of the first wall is located inside the blocking member 23 .

[0178] In this embodiment, a sealing member 23 is provided on the side of the first wall 211 of the shell 21 away from the electrode assembly 22, the sealing member 23 and the first wall 211 are in a sealed connection structure, and the sealing member 23 covers the first connection portion 24 formed by the mutual welding connection of the first electrode lead-out portion 222 and the first wall 211 in the thickness direction X of the first wall, so that the sealing member 23 can seal and plug the area where the first wall 211 of the shell 21 and the first electrode lead-out portion 222 of the electrode assembly 22 are mutually welded, so as to realize that the first connection portion 24 formed by the mutual welding connection of the first wall 211 of the shell 21 and the first electrode lead-out portion 222 of the electrode assembly 22 is a structure built into the interior of the battery cell 20, thereby effectively alleviating the phenomenon of airtight failure of the battery cell 20 caused by welding defects, welding cracks or welding penetration in the area where the first wall 211 and the first electrode lead-out portion 222 are welded to each other, thereby effectively reducing the risk of gas leakage or liquid leakage of the battery cell 20 during use, so as to improve the reliability of the battery cell 20.

[0179] According to some embodiments of the present application, referring to Figure 5 , Figure 6 and Figure 7 , and please refer to Figure 8 and Fig. 9 , Figure 8 A schematic diagram of the structure of the shell 212 of the housing 21 provided in some embodiments of the present application, Fig. 9 A front view of the shell 212 of the housing 21 provided in some embodiments of the present application facing the first wall 211 in the thickness direction X of the first wall. The first wall 211 is provided with an exhaust hole 2111 communicating with the accommodating cavity 2121, and the exhaust hole 2111 penetrates the first wall 211 along the thickness direction X of the first wall. The blocking member 23 is a pressure relief member, and the blocking member 23 is configured to be able to release the internal pressure of the battery cell 20, and the exhaust hole 2111 is configured to be able to guide the discharge in the accommodating cavity 2121 to the blocking member 23.

[0180] Among them, the sealing member 23 and the first wall 211 are sealed and connected to each other, so that the exhaust hole 2111 is not connected to the outside of the battery cell 20, and the sealing member 23 is a pressure relief component, so that the sealing member 23 can play a role in releasing the internal pressure of the battery cell 20, that is, the sealing member 23 is used to be destroyed when the internal pressure or temperature of the battery cell 20 reaches a predetermined value, so that the exhaust hole 2111 can be connected to the outside of the battery cell 20 through the sealing member 23, so that the exhaust hole 2111 can guide the emissions generated in the accommodating cavity 2121 due to thermal runaway of the battery cell 20 to the sealing member 23 for discharge, so as to release the internal pressure of the battery cell 20.

[0181] Optionally, the blocking member 23 may have various structures. For example, the blocking member 23 may be a component such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve or a safety valve.

[0182] It should be noted that the exhaust hole 2111 provided on the first wall 211 may be one or more. Figure 8 and Fig. 9 In the embodiment, a plurality of exhaust holes 2111 are provided on the first wall 211 .

[0183] In this embodiment, the sealing member 23 is provided as a pressure relief member for releasing the internal pressure of the battery cell 20, and an exhaust hole 2111 is provided on the first wall 211, which penetrates the first wall 211 and connects to the accommodating cavity 2121. When the battery cell 20 thermally runs away, the exhaust hole 2111 can also guide the exhaust inside the battery cell 20 to the sealing member 23 for release. Therefore, while the sealing member 23 seals the first connecting portion 24 to reduce the risk of airtight failure of the battery cell 20, the internal pressure of the battery cell 20 can be released through the sealing member 23. Therefore, the sealing member 23 can not only realize that the first connecting portion 24 is built into the interior of the battery cell 20, but also play a pressure relief role when the battery cell 20 thermally runs away, thereby optimizing the structure of the battery cell 20 and reducing the manufacturing cost of the battery cell 20.

[0184] According to some embodiments of the present application, see Figure 6 , Figure 7 and Figure 8 As shown, the blocking member 23 and the first wall 211 together define an exhaust cavity 26 , and the exhaust hole 2111 communicates with the exhaust cavity 26 and the accommodating cavity 2121 .

[0185] The blocking member 23 and the first wall 211 together define a vent cavity 26 , that is, the vent cavity 26 is formed between the blocking member 23 and the first wall 211 , and the vent cavity 26 is not connected to the outside of the battery cell 20 .

[0186] The exhaust hole 2111 communicates with the exhaust cavity 26 and the accommodating cavity 2121 , that is, one end of the exhaust hole 2111 extends to the cavity wall surface of the accommodating cavity 2121 , and the other end extends to the cavity wall surface of the exhaust cavity 26 .

[0187] In this embodiment, a vent cavity 26 is formed between the sealing member 23 and the first wall 211, and the vent cavity 26 is connected to the accommodating cavity 2121 inside the outer shell 21 through the vent hole 2111, so that the emissions generated when the battery cell 20 thermally runs away can enter the vent cavity 26 through the vent hole 2111 and then be discharged through the vent cavity 26. The battery cell 20 with such a structure can, on the one hand, have a certain buffering effect on the emissions generated when the battery cell 20 thermally runs away through the vent cavity 26, which is beneficial to alleviate the phenomenon of emissions accumulating in the accommodating cavity 2121. On the other hand, it can alleviate the phenomenon that the vent cavity 23 is only partially in contact with the emissions discharged from the vent hole 2111, which is beneficial to increase the contact area between the emissions and the vent cavity 23, thereby improving the timeliness and rate of pressure relief of the battery cell 20.

[0188] According to some embodiments of the present application, referring to Figure 6 and Figure 7 , and please refer to Fig.10 , Fig.10 A cross-sectional view of a plugging member 23 of a battery cell 20 provided in some embodiments of the present application. Along the thickness direction X of the first wall, the plugging member 23 has a first surface 231 facing the electrode assembly 22, and the first surface 231 abuts against the first wall 211. The first surface 231 is provided with a first groove 232, and the groove wall surface of the first groove 232 and the first wall 211 jointly define a venting cavity 26.

[0189] Among them, the first surface 231 is the surface of the sealing member 23 facing the electrode assembly 22 and abutting against the first wall 211 in the thickness direction X of the first wall, and a first groove 232 is arranged on the first surface 231, that is, the sealing member 23 abuts against one side of the first wall 211 in the thickness direction X of the first wall and is recessed in the direction away from the electrode assembly 22 to form the first groove 232.

[0190] The groove wall surface of the first groove 232 and the first wall 211 jointly define the exhaust cavity 26 , that is, the first wall 211 covers the groove opening of the first groove 232 , so that the first wall 211 and the groove wall surface of the first groove 232 jointly form the exhaust cavity 26 .

[0191] It should be noted that, in other embodiments, the exhaust cavity 26 defined by the first wall 211 and the blocking member 23 may have various structures. For example, the first groove 232 may be disposed on the side of the first wall 211 facing the blocking member 23, and the blocking member 23 may cover the first groove 232, so that the groove wall surface of the first groove 232 and the blocking member 23 may define the exhaust cavity 26. Figure 6 and Figure 7As shown, in an embodiment in which an assembly groove 2115 is provided on the fourth surface 2114 of the first wall 211 facing away from the electrode assembly 22, and the sealing member 23 is assembled in the assembly groove 2115, the sealing member 23 can also be spaced apart from the bottom surface of the assembly groove 2115 to form an exhaust cavity 26 between the sealing member 23 and the bottom surface of the assembly groove 2115.

[0192] In the present embodiment, the sealing member 23 has a first surface 231 facing the electrode assembly 22 and abutting against the first wall 211 in the thickness direction X of the first wall, and a first groove 232 is provided on the first surface 231, so that the groove wall surface of the first groove 232 and the first wall 211 together define an exhaust cavity 26 connected to the exhaust hole 2111. The battery cell 20 adopting this structure can reduce the difficulty of assembling the sealing member 23 and the first wall 211, and can reduce the difficulty of forming the exhaust cavity 26 between the sealing member 23 and the first wall 211. The structure is simple and easy to implement and assemble.

[0193] In some embodiments, in combination Figure 6 and Fig.10 As shown, along the thickness direction X of the first wall, the blocking member 23 has a second surface 233 facing away from the electrode assembly 22 , and a first protrusion 234 is formed on the side of the blocking member 23 facing away from the electrode assembly 22 and corresponding to the position of the first groove 232 , and the first protrusion 234 protrudes from the second surface 233 .

[0194] Exemplarily, the first groove 232 provided on the first surface 231 of the plugging member 23 is a structure formed by a stamping process, so that the first groove 232 is formed on the side of the plugging member 23 facing the electrode assembly 22, and the first protrusion 234 is formed on the side of the plugging member 23 away from the electrode assembly 22 and at a position corresponding to the first groove 232. Of course, the processing method of the first groove 232 provided on the first surface 231 of the plugging member 23 is not limited to this. In other embodiments, the first groove 232 provided on the first surface 231 of the plugging member 23 can also be formed by a processing process such as casting or milling.

[0195] In this embodiment, a first protrusion 234 protruding from the second surface 233 is formed on the side of the sealing member 23 facing away from the electrode assembly 22 and corresponding to the position of the first groove 232, so that the first groove 232 on the first surface 231 of the sealing member 23 is a structure that can be formed by a stamping process, so that the first groove 232 and the first protrusion 234 are respectively formed on both sides of the sealing member 23, thereby effectively reducing the difficulty of molding the sealing member 23 and improving the production efficiency of the battery cell 20.

[0196] According to some embodiments of the present application, see Fig.10As shown, the blocking member 23 is provided with a pressure relief groove 235, and the blocking member 23 is configured to be able to be split along at least part of the pressure relief groove 235 when the battery cell 20 is depressurized to release the internal pressure of the battery cell 20. Along the thickness direction X of the first wall, the projection of the pressure relief groove 235 is located in the first groove 232.

[0197] Among them, the sealing piece 23 forms a weak structure in the area where the pressure relief groove 235 is provided, so that the sealing piece 23 can be cracked along at least part of the bottom wall of the pressure relief groove 235 when the battery cell 20 releases pressure, thereby realizing the connection between the exhaust cavity 26 and the outside of the battery cell 20 to release the internal pressure of the battery cell 20.

[0198] Along the thickness direction X of the first wall, the projection of the pressure relief groove 235 is located in the first groove 232, that is, the pressure relief groove 235 is arranged corresponding to the first groove 232 in the thickness direction X of the first wall. If the pressure relief groove 235 is arranged on the side of the sealing member 23 facing the electrode assembly 22 in the thickness direction X of the first wall, the pressure relief groove 235 is arranged on the groove bottom surface of the first groove 232. If the pressure relief groove 235 is arranged on the side of the sealing member 23 away from the electrode assembly 22 in the thickness direction X of the first wall, the pressure relief groove 235 is arranged corresponding to the first groove 232 in the thickness direction X of the first wall.

[0199] In the present embodiment, a pressure relief groove 235 for pressure relief is provided on the sealing member 23, so that when the battery cell 20 thermally runs away, the sealing member 23 can release the internal pressure of the battery cell 20 after at least part of the pressure relief groove 235 is broken, so as to realize the function of the sealing member 23 to release the internal pressure of the battery cell 20. The structure is simple and easy to realize. The pressure relief groove 235 of the sealing member 23 is set to a structure whose projection in the thickness direction X of the first wall is located within the first groove 232, so that the sealing member 23 can be broken in the area where the exhaust cavity 26 is formed and release the emissions inside the battery cell 20, thereby improving the convenience and smoothness of the sealing member 23 in releasing the internal pressure of the battery cell 20, so as to improve the timeliness and rate of pressure relief of the battery cell 20.

[0200] In some embodiments, in combination Figure 6 and Fig.10 As shown, along the thickness direction X of the first wall, the pressure relief groove 235 is arranged on the side of the blocking member 23 away from the electrode assembly 22 .

[0201] It should be noted that in an embodiment in which a first protrusion 234 is formed on the side of the sealing member 23 away from the electrode assembly 22 and at a position corresponding to the first groove 232, the pressure relief groove 235 is arranged on the side of the first protrusion 234 away from the electrode assembly 22 in the thickness direction X of the first wall.

[0202] In this embodiment, the pressure relief groove 235 is arranged on the side of the sealing member 23 away from the electrode assembly 22 in the thickness direction X of the first wall so as to facilitate processing and forming the pressure relief groove 235 on the sealing member 23, which helps to reduce the processing difficulty of the sealing member 23.

[0203] According to some embodiments of the present application, referring to Figure 4 , Figure 6 and Fig. 9 , and please refer to Fig.11 and Fig.12 , Fig.11 This is a schematic structural diagram of a first current collecting member 2222 of a battery cell 20 provided in some embodiments of the present application. Fig.12 Schematic diagram of the assembly of the first wall 211 and the first electrode lead-out portion 222 of the battery cell 20 provided in some embodiments of the present application. The first electrode lead-out portion 222 includes a first pole tab 2221 and a first current collecting member 2222. Along the thickness direction X of the first wall, the first pole tab 2221 is connected to one end of the main body 221 close to the first wall 211, the first current collecting member 2222 is disposed between the first pole tab 2221 and the first wall 211, the first current collecting member 2222 is connected to the first pole tab 2221, and the first current collecting member 2222 is welded to the first wall 211 to form a first connecting portion 24. The first current collecting member 2222 is provided with a through hole 2222a which penetrates both sides of the first current collecting member 2222 along the thickness direction X of the first wall and is communicated with the exhaust hole 2111 . The through hole 2222a is configured to guide the exhaust in the accommodating cavity 2121 to the exhaust hole 2111 .

[0204] Among them, the first electrode lead-out portion 222 includes a first electrode tab 2221 and a first current collecting member 2222, the first electrode tab 2221 is connected to the main body 221, and the first current collecting member 2222 is located between the first wall 211 and the first electrode tab 2221 in the thickness direction X of the first wall, so that the first electrode tab 2221 is a structure connected to the first wall 211 through the first current collecting member 2222.

[0205] The first current collecting member 2222 is provided with a through hole 2222a, which penetrates both sides of the first current collecting member 2222 along the thickness direction X of the first wall. That is, the through hole 2222a on the first current collecting member 2222 is a structure extending along the thickness direction X of the first wall and penetrating the surface of the first current collecting member 2222 on both sides in the thickness direction X of the first wall.

[0206] The through hole 2222a is connected to the exhaust hole 2111, and the through hole 2222a is configured to guide the exhaust in the accommodating cavity 2121 to the exhaust hole 2111, that is, the exhaust generated when the battery cell 20 in the accommodating cavity 2121 is in thermal runaway can enter the exhaust hole 2111 through the through hole 2222a. Optionally, the through hole 2222a and the exhaust hole 2111 can be a structure that is directly connected or indirectly connected. In the embodiment of the present application, an exhaust gap 27 is formed between the first current collecting member 2222 and the third surface 2112 of the first wall 211. Correspondingly, the through hole 2222a on the first current collecting member 2222 and the exhaust hole 2111 on the first wall 211 are structures that are indirectly connected through the exhaust gap 27.

[0207] It should be noted that the through hole 2222a provided on the first current collecting member 2222 may be one or more. Fig.11 In the embodiment, the first current collecting member 2222 is a circular disc-shaped structure, and a plurality of through holes 2222a are provided on the first current collecting member 2222, and the plurality of through holes 2222a are arranged at intervals along the circumference of the first current collecting member 2222, and the through holes 2222a are strip-shaped holes, and the length direction of the through holes 2222a is the radial direction of the first current collecting member 2222. For example, in Fig.11 In the embodiment, four through holes 2222a are provided on the first current collecting member 2222. Of course, in other embodiments, the number of through holes 2222a provided on the first current collecting member 2222 may be two, three, five, six or seven.

[0208] In the present embodiment, the first electrode lead-out portion 222 is provided with a first electrode tab 2221 and a first current collecting member 2222, and the first current collecting member 2222 connects the first electrode tab 2221 and the first wall 211, so that the first electrode tab 2221 of the electrode assembly 22 is a structure welded to the first wall 211 through the first current collecting member 2222, thereby reducing the difficulty of mutual electrical connection between the electrode assembly 22 and the first wall 211, and reducing the difficulty of welding between the first electrode lead-out portion 222 and the first wall 211, which is beneficial to improving the assembly efficiency of the battery cell 20. Among them, by setting a through hole 2222a that penetrates the first current collecting member 2222 along the thickness direction X of the first wall on the first current collecting member 2222, and the through hole 2222a is connected with the exhaust hole 2111 on the first wall 211, when the battery cell 20 has thermal runaway, the exhaust inside the electrode assembly 22 can enter the exhaust hole 2111 of the first wall 211 through the through hole 2222a of the first current collecting member 2222 and then be discharged through the sealing member 23, thereby effectively improving the exhaust smoothness inside the battery cell 20 and improving the pressure relief rate of the battery cell 20.

[0209] In some embodiments, see Fig.12 As shown, along the thickness direction X of the first wall, at least a portion of the projection of at least one through hole 2222a is located within one exhaust hole 2111 .

[0210] Among them, at least part of the projection of at least one through hole 2222a is located in an exhaust hole 2111, that is, part or all of the projection of a through hole 2222a in the thickness direction X of the first wall may be located in an exhaust hole 2111, or part or all of the projections of multiple through holes 2222a in the thickness direction X of the first wall may be located in one exhaust hole 2111, or the projections of the through hole 2222a in the thickness direction X of the first wall may be located in multiple exhaust holes 2111.

[0211] For example, in Fig.12 In the embodiment, each through hole 2222a is arranged corresponding to one exhaust hole 2111 in the thickness direction X of the first wall, and the entire projection of each through hole 2222a in the thickness direction X of the first wall is located within one exhaust hole 2111.

[0212] In this embodiment, by setting at least a portion of the projection of at least one through hole 2222a on the first current collecting member 2222 in the thickness direction X of the first wall to be located within an exhaust hole 2111, so that the through hole 2222a can guide the exhaust in the accommodating cavity 2121 to the exhaust hole 2111, the smoothness of the exhaust inside the battery cell 20 passing through the through hole 2222a into the exhaust hole 2111 can be effectively improved, so as to further improve the exhaust smoothness inside the battery cell 20, and further improve the timeliness and rate of pressure relief of the battery cell 20.

[0213] According to some embodiments of the present application, see Figure 6 and Figure 7 As shown, the first electrode lead-out portion 222 includes a first electrode tab 2221 and a first current collecting member 2222. Along the thickness direction X of the first wall, the first electrode tab 2221 is connected to one end of the main body 221 close to the first wall 211, and the first current collecting member 2222 is disposed between the first electrode tab 2221 and the first wall 211. The first current collecting member 2222 is connected to the first electrode tab 2221, and the first current collecting member 2222 is welded to the first wall 211 to form a first connection portion 24. Along the thickness direction X of the first wall, the first wall 211 has a third surface 2112 facing the electrode assembly 22, and the first wall 211 has a protrusion 2113 protruding from the third surface 2112, and the protrusion 2113 is welded to the first current collecting member 2222 to form the first connection portion 24, and an exhaust gap 27 is formed between the first current collecting member 2222 and the third surface 2112, and the exhaust gap 27 is connected to the exhaust hole 2111.

[0214] The third surface 2112 is a surface on which the first wall 211 is provided with a protruding portion 2113. Figure 6 In the figure, the first wall 211 is provided with an assembly groove 2115 on the fourth surface 2114 facing away from the electrode assembly 22 in the thickness direction X of the first wall, and a second protrusion 2117 protruding from the fifth surface 2116 is formed on the side of the first wall 211 facing the electrode assembly 22, and the protrusion 2113 protrudes from the side of the second protrusion 2117 facing the electrode assembly 22 in the thickness direction X of the first wall, then the surface of the second protrusion 2117 facing the electrode assembly 22 in the thickness direction X of the first wall is the third surface 2112.

[0215] The protrusion 2113 protrudes from the third surface 2112 of the first wall 211, so that the protrusion 2113 can allow the first current collecting member 2222 of the first electrode lead-out portion 222 to abut against and be welded in the thickness direction X of the first wall, so that the third surface 2112 and the first current collecting member 2222 are spaced apart from each other in the thickness direction X of the first wall to form an exhaust gap 27 between the first current collecting member 2222 and the third surface 2112.

[0216] The exhaust gap 27 is connected to the exhaust hole 2111, that is, one end of the exhaust hole 2111 extends to the third surface 2112, so that the exhaust hole 2111 can be connected to the exhaust gap 27. Correspondingly, the other end of the exhaust hole 2111 extends to the bottom surface of the assembly groove 2115, so that the exhaust hole 2111 is a structure arranged on the bottom surface of the assembly groove 2115 and penetrating the bottom wall of the assembly groove 2115 along the thickness direction X of the first wall.

[0217] In the present embodiment, the first electrode lead-out portion 222 is provided with a first pole ear 2221 and a first current collecting member 2222, and the first current collecting member 2222 connects the first pole ear 2221 and the first wall 211, so that the first pole ear 2221 of the electrode assembly 22 is a structure that is welded to the first wall 211 through the first current collecting member 2222, thereby reducing the difficulty of mutual electrical connection between the electrode assembly 22 and the first wall 211, and reducing the difficulty of welding between the first electrode lead-out portion 222 and the first wall 211, thereby facilitating the assembly efficiency of the battery cell 20, wherein, by A protrusion 2113 welded to the first current collecting member 2222 is provided on the third surface 2112 of 22, and the protrusion 2113 protrudes from the third surface 2112 to form an exhaust gap 27 connected to the exhaust hole 2111 between the first current collecting member 2222 and the third surface 2112 of the first wall 211, so that the emissions generated by the battery cell 20 during thermal runaway can enter the exhaust hole 2111 of the first wall 211 through the exhaust gap 27 and then be discharged through the sealing member 23, thereby effectively improving the exhaust smoothness inside the battery cell 20, so as to improve the timeliness and rate of pressure relief of the battery cell 20.

[0218] According to some embodiments of the present application, see Figure 3 , Figure 8 and Fig. 9 As shown, the housing 21 is cylindrical, and the central axis of the housing 21 extends along the thickness direction X of the first wall. The first wall 211 is provided with a plurality of exhaust holes 2111, including a plurality of first exhaust holes 2111a, which are arranged at intervals around the central axis of the housing 21.

[0219] The housing 21 is cylindrical, and the central axis of the housing 21 extends along the thickness direction X of the first wall. Correspondingly, the projection of the first wall 211 in the thickness direction X of the first wall is circular.

[0220] The plurality of first exhaust holes 2111a are arranged at intervals around the central axis of the shell 21 , that is, in a plane perpendicular to the thickness direction X of the first wall, the orthographic projections of the plurality of first exhaust holes 2111a are arranged at intervals around the center of the orthographic projection of the first wall 211 .

[0221] For example, in Fig. 9 In the embodiment, four first exhaust holes 2111 a are provided on the first wall 211 , and the four exhaust holes 2111 a are arranged at intervals along the circumference of the first wall 211 .

[0222] In this embodiment, the outer shell 21 of the battery cell 20 is cylindrical, and the central axis of the outer shell 21 extends along the thickness direction X of the first wall. By arranging a plurality of first exhaust holes 2111a on the first wall 211, and the plurality of first exhaust holes 2111a are arranged at intervals around the central axis of the outer shell 21, the exhaust area and exhaust region of the exhaust materials generated by the battery cell 20 during thermal runaway can be increased through the exhaust holes 2111 to guide the exhaust materials in the accommodating cavity 2121 to the sealing member 23, thereby effectively improving the rate at which the exhaust holes 2111 guide the exhaust materials in the accommodating cavity 2121 to the sealing member 23, thereby improving the timeliness and rate of pressure relief of the battery cell 20.

[0223] In some embodiments, see Figure 8 and Fig. 9 As shown, the projection of the first exhaust hole 2111 a in the thickness direction X of the first wall is in a fan-shaped shape extending along the circumference of the shell 21 .

[0224] Exemplarily, the center of the projection of the first exhaust hole 2111a in the direction X of the thickness of the first wall in the form of a fan ring is concentrically arranged with the center of the projection of the first wall 211 in the direction X of the thickness of the first wall, that is, the center of the projection of the first exhaust hole 2111a in the direction X of the thickness of the first wall in the form of a fan ring is located on the central axis of the housing 21. It should be noted that the fan ring is the shape of a part of a circular ring structure cut off by a fan.

[0225] In this embodiment, by setting the shape of the first exhaust hole 2111a to a fan-shaped shape extending along the circumference of the outer shell 21, on the one hand, it is convenient to form a plurality of first exhaust holes 2111a spaced apart around the central axis of the outer shell 21 on the first wall 211, which is conducive to reducing the difficulty of setting a plurality of first exhaust holes 2111a on the first wall 211; on the other hand, it is possible to optimize the layout of the plurality of first exhaust holes 2111a on the first wall 211, and to maximize the exhaust area of ​​the first exhaust holes 2111a under the same area, so as to further improve the rate at which the first exhaust holes 2111a guide the exhaust in the accommodating cavity 2121 to the blocking member 23.

[0226] According to some embodiments of the present application, see Figure 5 , Figure 6 , Figure 8 and Fig. 9 As shown, the electrode assembly 22 has a central through hole 224 extending along the thickness direction X of the first wall, and the central through hole 224 passes through both ends of the main body 221 in the thickness direction X of the first wall. The plurality of exhaust holes 2111 also include a second exhaust hole 2111b, and the plurality of first exhaust holes 2111a are arranged around the second exhaust hole 2111b, and at least part of the projection of the second exhaust hole 2111b is located in the central through hole 224 along the thickness direction X of the first wall.

[0227] Among them, the main body 221 of the electrode assembly 22 is cylindrical, and the central axis of the central through hole 224 coincides with the central axis of the main body 221 of the electrode assembly 22. Exemplarily, the projection of the second exhaust hole 2111b in the thickness direction X of the first wall is circular, and the center of the projection of the second exhaust hole 2111b in the thickness direction X of the first wall is located on the central axis of the central through hole 224, that is, the center of the projection of the second exhaust hole 2111b in the thickness direction X of the first wall is concentric with the center of the projection of the first wall 211 in the thickness direction X of the first wall.

[0228] Exemplarily, the entire projection of the second exhaust hole 2111b in the thickness direction X of the first wall is located inside the central through hole 224. Of course, in other embodiments, the entire projection of the central through hole 224 in the thickness direction X of the first wall may be located inside the second exhaust hole 2111b, or the projection of the central through hole 224 in the thickness direction X of the first wall may partially overlap with the projection of the second exhaust hole 2111b in the thickness direction X of the first wall.

[0229] In this embodiment, by setting the second exhaust hole 2111b on the first wall 211, the multiple first exhaust holes 2111a are a structure arranged around the second exhaust hole 2111b, and at least a part of the projection of the second exhaust hole 2111b in the thickness direction X of the first wall is located in the central through hole 224 of the electrode assembly 22. The battery cell 20 adopting this structure can, on the one hand, further increase the exhaust area of ​​the exhaust holes 2111 on the first wall 211, and can effectively optimize the layout of the first exhaust holes 2111a and the second exhaust holes 2111b in the multiple exhaust holes 2111. On the other hand, it can also achieve that the emissions generated by the battery cell 20 during thermal runaway enter the second exhaust holes 2111b from the central through hole 224 of the electrode assembly 22 and then pass through the blocking member 23 for discharge, which is conducive to further improving the rate at which the exhaust holes 2111 guide the emissions in the accommodating cavity 2121 to the blocking member 23, so as to improve the timeliness and rate of pressure relief of the battery cell 20.

[0230] According to some embodiments of the present application, see Figure 4 , Figure 5 and Figure 6 As shown, the first electrode lead-out portion 222 includes a first electrode tab 2221 and a first current collecting member 2222. The first electrode tab 2221 is connected to one end of the main body 221 close to the first wall 211 in the thickness direction X of the first wall. The first current collecting member 2222 is disposed between the first electrode tab 2221 and the first wall 211 along the thickness direction X of the first wall, the first current collecting member 2222 is connected to the first electrode tab 2221, and the first current collecting member 2222 is welded to the first wall 211 to form a first connection portion 24.

[0231] The first electrode tab 2221 is connected to one end of the main body 221 close to the first wall 211 in the thickness direction X of the first wall. The first current collecting member 2222 is disposed between the first electrode tab 2221 and the first wall 211 along the thickness direction X of the first wall, that is, the main body 221, the first electrode tab 2221, the first current collecting member 2222 and the first wall 211 are sequentially arranged along the thickness direction X of the first wall, so that the electrode tab of the electrode assembly 22 is a structure connected to the first wall 211 through the first current collecting member 2222, and the first current collecting member 2222 and the first wall 211 are welded to each other to form the first connection portion 24.

[0232] Optionally, the connection structure between the first electrode tab 2221 and the first current collecting member 2222 may be various, for example, welding connection or abutment connection.

[0233] In the present embodiment, the first electrode lead-out portion 222 is provided with a first pole ear 2221 and a first current collecting member 2222, the first pole ear 2221 is connected to the main body 221, and the first current collecting member 2222 is connected to the first pole ear 2221 and is welded to the first wall 211 to form a first connecting portion 24, so that the first pole ear 2221 of the electrode assembly 22 is a structure welded to the first wall 211 through the first current collecting member 2222, thereby reducing the difficulty of electrical connection between the electrode assembly 22 and the first wall 211, and reducing the difficulty of welding between the first electrode lead-out portion 222 and the first wall 211, which is beneficial to improving the assembly efficiency of the battery cell 20.

[0234] According to some embodiments of the present application, Figure 6 and Fig.12 As shown, the first current collecting member 2222 is connected to the first electrode tab 2221 by welding to form a second connection portion 2223 .

[0235] The second connection portion 2223 is a weld mark formed by a region where the first current collecting member 2222 and the first electrode tab 2221 are welded to each other.

[0236] In this embodiment, the first current collecting member 2222 and the first pole tab 2221 are connected by a welding connection structure, which is beneficial to improving the connection stability between the first current collecting member 2222 and the first pole tab 2221, so as to reduce the risk of the first current collecting member 2222 and the first pole tab 2221 being separated from each other during use, thereby improving the reliability and stability of the battery cell 20.

[0237] In some embodiments, see Fig.12 As shown, along the thickness direction X of the first wall, the projection of the second connection portion 2223 does not overlap with the projection of the first connection portion 24 .

[0238] In this embodiment, the first connection portion 24 formed by welding the first current collecting member 2222 to the first wall 211 and the second connection portion 2223 formed by welding the first current collecting member 2222 to the first pole tab 2221 are arranged to have non-overlapping projections in the thickness direction X of the first wall, thereby reducing the interference between the first connection portion 24 and the second connection portion 2223, and alleviating the phenomenon that the welding molten pool between the first current collecting member 2222 and the first wall 211 and the welding molten pool between the first current collecting member 2222 and the first pole tab 2221 overlap with each other, thereby facilitating improving the welding quality between the first current collecting member 2222 and the first wall 211 and between the first current collecting member 2222 and the first pole tab 2221.

[0239] According to some embodiments of the present application, see Figure 8 , Fig. 9 and Fig.12 As shown, the first wall 211 is provided with an exhaust hole 2111 communicating with the accommodating cavity 2121 , and the exhaust hole 2111 penetrates the first wall 211 along the thickness direction X of the first wall. Along the thickness direction X of the first wall, the projection of at least one second connection portion 2223 is located in one exhaust hole 2111 .

[0240] Among them, the projection of at least one second connection part 2223 is located in an exhaust hole 2111, that is, the projection of a second connection part 2223 in the thickness direction X of the first wall can be located in an exhaust hole 2111, or the projections of multiple second connection parts 2223 in the thickness direction X of the first wall can be located in an exhaust hole 2111.

[0241] For example, in Fig.12 In the embodiment, each second connection portion 2223 is arranged corresponding to one exhaust hole 2111 in the thickness direction X of the first wall, so that the entire projection of each second connection portion 2223 in the thickness direction X of the first wall is located in one exhaust hole 2111.

[0242] In this embodiment, the first wall 211 is provided with exhaust holes 2111 penetrating through both sides of the first wall 211 along the thickness direction X of the first wall. At least one second connection portion 2223 formed by welding the first current collecting member 2222 and the first pole ear 2221 is arranged so that the projection in the thickness direction X of the first wall is located inside the exhaust hole 2111. The battery cell 20 with such a structure enables the exhaust hole 2111 to avoid the second connection portion 2223 to a certain extent, which is conducive to reducing the interference between the second connection portion 2223 and the first wall 211. On the other hand, it can also achieve the first After the electrode assembly 22 is assembled into the outer shell 21, the first current collecting component 2222 and the first pole lug 2221 are welded and connected from the exhaust hole 2111, so that the welding assembly between the first current collecting component 2222 and the first pole lug 2221 will not be limited by the assembly order of the electrode assembly 22 and the outer shell 21, thereby optimizing the assembly process of the battery cell 20, and after the first current collecting component 2222 and the first pole lug 2221 are welded and connected from the exhaust hole 2111, the first current collecting component 2222 and the first pole lug 2221 can also be welded and connected, which is beneficial to improving the assembly efficiency of the battery cell 20.

[0243] According to some embodiments of the present application, see Fig.12 As shown, the first current collecting member 2222 is welded to the first wall 211 to form a plurality of first connection parts 24, and the first current collecting member 2222 is welded to the first electrode tab 2221 to form a plurality of second connection parts 2223. The plurality of first connection parts 24 and the plurality of second connection parts 2223 are alternately and spacedly arranged along the circumference of the first current collecting member 2222.

[0244] Among them, multiple first connection parts 24 and multiple second connection parts 2223 are alternately and spacedly arranged along the circumference of the first current collecting component 2222, that is, on the circumference of the first current collecting component 2222, a second connection part 2223 is arranged between every two adjacent first connection parts 24, and conversely, a first connection part 24 is arranged between every two adjacent second connection parts 2223.

[0245] Exemplarily, the battery cell 20 is cylindrical, and the central axis of the battery cell 20 extends along the thickness direction X of the first wall. Correspondingly, the projection of the first current collecting member 2222 in the thickness direction X of the first wall is circular, and the plurality of first connection portions 24 and the plurality of second connection portions 2223 are structures that are alternately arranged along the circumference of the first current collecting member 2222 and around the central axis of the battery cell 20.

[0246] For example, in Fig.12In the figure, the first current collecting member 2222 is welded to the first wall 211 to form four first connection parts 24, and the first current collecting member 2222 is welded to the first pole ear 2221 to form four second connection parts 2223. Each first connection part 24 and each second connection part 2223 are structures extending along the radial direction of the first current collecting member 2222, and the four first connection parts 24 and the four second connection parts 2223 are alternately arranged along the circumference of the first current collecting member 2222 and around the central axis of the battery cell 20.

[0247] In this embodiment, by welding the first current collecting member 2222 and the first wall 211 to form a plurality of first connecting portions 24, it is beneficial to further improve the connection reliability between the first current collecting member 2222 and the first wall 211. Similarly, by welding the first current collecting member 2222 and the first pole tab 2221 to form a plurality of second connecting portions 2223, it is beneficial to further improve the connection reliability between the first current collecting member 2222 and the first pole tab 2221. In particular, by arranging the plurality of first connecting portions 24 and the plurality of second connecting portions 2223 in a structure alternately and spaced apart along the circumference of the first current collecting member 2222, on the one hand, the first connecting portions 24 and the second connecting portions 2223 can be reduced. 23, so as to alleviate the phenomenon of mutual overlap between the welding molten pool of the first current collecting component 2222 and the first wall 211 and the welding molten pool of the first current collecting component 2222 and the first pole lug 2221, which is beneficial to improving the welding quality between the first current collecting component 2222 and the first wall 211 and between the first current collecting component 2222 and the first pole lug 2221. On the other hand, it can improve the balance of current flow between the first pole lug 2221 and the first current collecting component 2222 and the first current collecting component 2222 and the first wall 211, which is beneficial to improving the current passing capacity and current passing effect between the first pole lug 2221 and the first current collecting component 2222 and the first current collecting component 2222 and the first wall 211.

[0248] According to some embodiments of the present application, see Figure 4 , Figure 5 and Fig.12 As shown, the first pole tab 2221 is a cylindrical structure whose central axis extends along the thickness direction X of the first wall, and the second connection portion 2223 extends along the radial direction of the first pole tab 2221. Along the radial direction of the first pole tab 2221, the size of the first pole tab 2221 is L1, the size of the second connection portion 2223 is L2, and 0.5≤L2 / L1≤1.

[0249] Among them, the battery cell 20 is cylindrical, and the central axis of the battery cell 20 extends along the thickness direction X of the first wall. Correspondingly, the main body 221 of the electrode assembly 22 is also a cylindrical structure with a central axis extending along the thickness direction X of the first wall. The first pole ear 2221 is formed at one end of the main body 221. Correspondingly, the first pole ear 2221 is also a cylindrical structure with a central axis extending along the thickness direction X of the first wall. The first pole ear 2221 and the first current collecting member 2222 are welded and connected to form a plurality of second connection portions 2223. The plurality of second connection portions 2223 are structures arranged at intervals along the circumference of the first pole ear 2221, and each second connection portion 2223 extends radially along the first pole ear 2221.

[0250] L1 is the diameter of the first pole lug 2221, and L2 is the length of the second connection portion 2223 in the radial direction of the first pole lug 2221. For example, L2 / L1 may be 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95 or 1, etc.

[0251] In this embodiment, by setting the radial dimension of the second connecting portion 2223 to be larger than half or more than half of the radial dimension of the first pole ear 2221, each circle of the first pole ear 2221 from the inside to the outside can form a welding relationship with the first current collecting member 2222, thereby shortening the internal current flow path of the electrode assembly 22 and improving the internal current flow effect of the electrode assembly 22, so as to reduce the internal resistance of the electrode assembly 22 during use, which is beneficial to improve the performance and stability of the battery cell 20.

[0252] According to some embodiments of the present application, see Figure 6 , Figure 7 and Figure 8 As shown, along the thickness direction X of the first wall, the first wall 211 has a fourth surface 2114 away from the electrode assembly 22, and the fourth surface 2114 is the surface of the first wall 211 farthest from the electrode assembly 22. The fourth surface 2114 is provided with a mounting groove 2115, the first electrode lead-out portion 222 is welded and connected to the bottom wall of the mounting groove 2115 to form a first connecting portion 24, and at least a portion of the blocking member 23 is disposed in the mounting groove 2115.

[0253] Among them, the fourth surface 2114 is the outer surface of the first wall 211 farthest from the electrode assembly 22 in the thickness direction X of the first wall, and the fourth surface 2114 is provided with an assembly groove 2115, that is, a partial area of ​​the fourth surface 2114 is recessed in the direction close to the electrode assembly 22 to form an assembly groove 2115.

[0254] The first electrode lead-out portion 222 is welded to the bottom wall of the assembly groove 2115 to form a first connection portion 24 , that is, the first connection portion 24 formed by the mutual welding of the first electrode lead-out portion 222 and the first wall 211 has its projection in the thickness direction X of the first wall located on the bottom surface of the assembly groove 2115 .

[0255] At least part of the blocking member 23 is arranged in the assembly groove 2115, that is, the blocking member 23 can be only partially accommodated in the assembly groove 2115 in the thickness direction X of the first wall, or the blocking member 23 can be entirely accommodated in the assembly groove 2115 in the thickness direction X of the first wall.

[0256] It should be noted that in the embodiment in which the exhaust hole 2111 is provided on the first wall 211 , the exhaust hole 2111 is provided on the bottom surface of the assembly groove 2115 .

[0257] In this embodiment, an assembly groove 2115 is provided on the fourth surface 2114 of the first wall 211 on the side away from the electrode assembly 22, and the bottom wall of the assembly groove 2115 is welded to the first electrode lead-out portion 222 to form a first connection portion 24, and at least a portion of the sealing member 23 in the thickness direction X of the first wall is provided in the assembly groove 2115, so that on the one hand, it is convenient for the sealing member 23 to cover and seal the first connection portion 24, which is beneficial to reduce the difficulty of covering and sealing the first connection portion 24 by the sealing member 23, and can improve the effect of covering and sealing the first connection portion 24 by the sealing member 23, and on the other hand, the assembly groove 2115 can also play a certain role in assembly positioning and protection of the sealing member 23, which can effectively reduce the assembly difficulty between the sealing member 23 and the first wall 211, which is beneficial to improve the assembly efficiency of the sealing member 23 and the first wall 211, and can effectively reduce the wear and bump of the sealing member 23 during use, which is beneficial to improve the service life of the sealing member 23.

[0258] In some embodiments, see Figure 6 As shown, along the thickness direction X of the first wall, the blocking member 23 does not extend beyond the fourth surface 2114. In other words, the blocking member 23 is a structure that is entirely accommodated in the assembly groove 2115 along the thickness direction X of the first wall.

[0259] In this embodiment, by setting the blocking member 23 so as not to extend beyond the fourth surface 2114 in the thickness direction X of the first wall, the blocking member 23 is made to be a structure that is entirely accommodated in the assembly groove 2115 in the thickness direction X of the first wall, thereby further enhancing the protective effect of the assembly groove 2115 on the blocking member 23, thereby further reducing the wear and bumping of the blocking member 23 during use.

[0260] According to some embodiments of the present application, see Figure 6 and Figure 7 As shown, along the thickness direction X of the first wall, the first wall 211 also has a fifth surface 2116 facing the electrode assembly 22, and a second protrusion 2117 is formed on the side of the first wall 211 facing the electrode assembly 22 and corresponding to the position of the assembly groove 2115, and the second protrusion 2117 is protruding on the fifth surface 2116.

[0261] Exemplarily, the assembly groove 2115 provided on the fourth surface 2114 of the first wall 211 is a structure formed by a stamping process, so that the assembly groove 2115 is formed on the side of the first wall 211 away from the electrode assembly 22, and the second protrusion 2117 is formed on the side of the first wall 211 facing the electrode assembly 22 and at a position corresponding to the assembly groove 2115. Of course, the processing method of the assembly groove 2115 provided on the fourth surface 2114 of the first wall 211 is not limited to this. In other embodiments, the assembly groove 2115 provided on the fourth surface 2114 of the first wall 211 can also be formed by a processing process such as casting or milling.

[0262] In this embodiment, a second protrusion 2117 protruding from the fifth surface 2116 is formed on the side of the first wall 211 facing the electrode assembly 22 and corresponding to the position of the assembly groove 2115, so that the assembly groove 2115 on the fourth surface 2114 of the first wall 211 is a structure that can be formed by a stamping process, so that the assembly groove 2115 and the second protrusion 2117 are respectively formed on both sides of the first wall 211, thereby effectively reducing the molding difficulty of the first wall 211 of the outer shell 21, so as to improve the production efficiency of the battery cell 20.

[0263] According to some embodiments of the present application, see Figure 6 As shown, the outer peripheral surface of the blocking member 23 is welded to the groove side surface of the assembly groove 2115 to form a third connecting portion 28, and the third connecting portion 28 is an annular structure.

[0264] The third connection portion 28 is a weld mark formed by the area where the outer peripheral surface of the blocking member 23 and the groove side surface of the assembly groove 2115 are welded to each other.

[0265] The third connection portion 28 is an annular structure, that is, the third connection portion 28 is an annular structure arranged around the blocking member 23 along the circumference of the blocking member 23 .

[0266] In this embodiment, the outer peripheral surface of the sealing member 23 and the groove side surface of the assembly groove 2115 are welded to each other to form a third connecting portion 28 arranged around the sealing member 23, so as to achieve a sealed connection between the sealing member 23 and the first wall 211 through the third connecting portion 28. The battery cell 20 adopting this structure can, on the one hand, improve the connection stability between the sealing member 23 and the first wall 211, which is beneficial to reduce the risk of the sealing member 23 being detached during use, and can reduce the difficulty of the sealing connection between the sealing member 23 and the first wall 211, so as to improve the assembly efficiency of the sealing member 23 and the first wall 211. On the other hand, the structure of the sealed connection formed by welding the outer peripheral surface of the sealing member 23 and the groove side surface of the assembly groove 2115 can improve the effect of the sealing connection between the sealing member 23 and the first wall 211, and can reduce the influence of the third connecting portion 28 on the airtightness of the battery cell 20.

[0267] According to some embodiments of the present application, see Figure 6 , Figure 7 and Figure 8 As shown, the assembly groove 2115 includes a first groove 2115a and a second groove 2115b, the first groove 2115a is arranged on the fourth surface 2114, the second groove 2115b is arranged on the bottom surface of the first groove 2115a, the first electrode lead-out portion 222 is welded to the bottom wall of the second groove 2115b to form a first connection portion 24, and the outer peripheral surface of the sealing member 23 is welded to the side surface of the second groove 2115b to form a third connection portion 28.

[0268] Among them, the assembly groove 2115 includes a first groove 2115a and a second groove 2115b, the first groove 2115a is arranged on the fourth surface 2114, and the second groove 2115b is arranged on the bottom surface of the first groove 2115a, that is, the assembly groove 2115 is a two-level stepped groove structure including the first groove 2115a and the second groove 2115b.

[0269] The first electrode lead-out portion 222 is welded to the bottom wall of the second groove 2115b to form a first connection portion 24, that is, the first connection portion 24 formed by welding the first electrode lead-out portion 222 and the first wall 211 to each other has its projection in the thickness direction X of the first wall located on the bottom surface of the second groove 2115b.

[0270] In this embodiment, the assembly groove 2115 includes a first groove 2115a provided on the fourth surface 2114 and a second groove 2115b provided on the groove bottom surface of the first groove 2115a, so that the assembly groove 2115 is a stepped groove structure arranged along the thickness direction X of the first wall, and the groove bottom wall of the second groove 2115b is welded to the first electrode lead-out portion 222 to form a first connecting portion 24, and the outer peripheral surface of the blocking member 23 is welded to the groove side surface of the second groove 2115b to form a third connecting portion 28 of an annular structure, so as to facilitate the blocking. The component 23 covers and seals the first connection part 24, which is conducive to reducing the difficulty of covering and sealing the first connection part 24 by the sealing component 23, and can improve the effect of covering and sealing the first connection part 24 by the sealing component 23. On the other hand, the first groove 2115a can also accommodate and protect the portion of the third connection part 28 protruding from the bottom surface of the groove 2115a, which is conducive to reducing the interference between the third connection part 28 and other components, and is conducive to reducing the phenomenon of bumps and wear of the third connection part 28 during use.

[0271] In some embodiments, see Figure 6 As shown, along the thickness direction X of the first wall, the third connection portion 28 does not extend beyond the fourth surface 2114. That is, the portion of the third connection portion 28 protruding from the bottom surface of the first groove 2115a is located in the first groove 2115a and does not extend beyond the notch of the first groove 2115a.

[0272] In this embodiment, the third connection part 28 is set to a structure that does not exceed the fourth surface 2114 in the thickness direction X of the first wall, so that the portion of the third connection part 28 protruding from the bottom surface of the first groove 2115a is a structure that is entirely located in the first groove 2115a, thereby further enhancing the protective effect of the first groove 2115a on the third connection part 28, which is beneficial to further reduce the interference between the third connection part 28 and other components, and is beneficial to further reduce the phenomenon of bumps and wear on the third connection part 28 during use.

[0273] In some embodiments, in combination Figure 6 and Fig.10 As shown, along the thickness direction X of the first wall, the sealing member 23 has a second surface 233 facing away from the electrode assembly 22, the second surface 233 is connected to the outer peripheral surface of the sealing member 23, and the second surface 233 is coplanar with the bottom surface of the first groove 2115a, that is, the second surface 233 of the sealing member 23 is flush with the bottom surface of the first groove 2115a.

[0274] In this embodiment, the second surface 233 of the sealing member 23 which is facing away from the side of the electrode assembly 22 and is interconnected with the outer peripheral surface of the sealing member 23 is set to a structure that is coplanar with the bottom surface of the first groove 2115a, so that the second surface 233 of the sealing member 23 and the bottom surface of the first groove 2115a are flush with each other, thereby further improving the welding quality between the outer peripheral surface of the sealing member 23 and the groove side surface of the second groove 2115b, thereby improving the assembly quality between the sealing member 23 and the first wall 211.

[0275] In some embodiments, see Figure 6 As shown, along the thickness direction X of the first wall, the blocking member 23 abuts against the bottom surface of the second groove 2115b.

[0276] In this embodiment, by setting the sealing member 23 as a structure that abuts against the bottom surface of the second groove 2115b in the thickness direction X of the first wall, the bottom surface of the second groove 2115b can also play a certain supporting and positioning role for the sealing member 23. On the one hand, it can further improve the welding quality between the sealing member 23 and the first wall 211, which is conducive to further improving the assembly quality and assembly stability of the sealing member 23 and the first wall 211. On the other hand, it can further reduce the assembly difficulty between the sealing member 23 and the first wall 211, so as to improve the assembly efficiency of the sealing member 23 and the first wall 211.

[0277] According to some embodiments of the present application, see Figure 6 , Figure 7 , Figure 8 and Fig.12 As shown, a second groove 2118 is provided on the bottom surface of the assembly groove 2115 , and along the thickness direction X of the first wall, the projection of the first connecting portion 24 is located in the second groove 2118 .

[0278] Among them, the second groove 2118 is arranged on the bottom surface of the assembly groove 2115, that is, a local area of ​​the bottom surface of the assembly groove 2115 is recessed in the direction close to the electrode assembly 22 and forms the second groove 2118. It should be noted that in the embodiment where the assembly groove 2115 includes a first groove 2115a and a second groove 2115b, the second groove 2118 is arranged on the bottom surface of the second groove 2115b.

[0279] Along the thickness direction X of the first wall, the projection of the first connection portion 24 is located in the second groove 2118 , that is, the groove bottom wall of the second groove 2118 is welded to the first electrode lead-out portion 222 to form the first connection portion 24 .

[0280] In this embodiment, a second groove 2118 is provided on the groove bottom surface of the assembly groove 2115, and the projection of the first connection portion 24 formed by welding the first electrode lead portion 222 to the groove bottom wall of the assembly groove 2115 in the thickness direction X of the first wall is located in the second groove 2118, so that the first connection portion 24 is a structure formed by welding the groove bottom wall of the second groove 2118 and the first electrode lead portion 222. The battery cell 20 with such a structure is convenient for the sealing member 23 to cover and seal the first connection portion 24, which is conducive to reducing the difficulty of covering and sealing the first connection portion 24 by the sealing member 23, and can improve the effect of covering and sealing the first connection portion 24 by the sealing member 23. On the other hand, the second groove 2118 can accommodate the portion of the first connection portion 24 protruding from the groove bottom surface of the second groove 2118, which is conducive to reducing the interference between the first connection portion 24 and the sealing member 23 arranged in the assembly groove 2115.

[0281] In some embodiments, see Figure 6 As shown, along the thickness direction X of the first wall, the blocking member 23 covers the second groove 2118 , that is, the projection of the second groove 2118 in the thickness direction X of the first wall is located inside the blocking member 23 .

[0282] In this embodiment, the blocking member 23 is arranged to cover the second groove 2118 in the thickness direction X of the first wall, so that the blocking member 23 can cover the first connection portion 24 and improve the covering and sealing effect of the blocking member 23 on the first connection portion 24.

[0283] According to some embodiments of the present application, see Figure 6 and Figure 7 As shown, along the thickness direction X of the first wall, the bottom wall of the assembly groove 2115 has a third surface 2112 facing the electrode assembly 22, and a protrusion 2113 protruding from the third surface 2112 is formed on the side of the bottom wall of the assembly groove 2115 facing the electrode assembly 22 and corresponding to the position of the second groove 2118, and the protrusion 2113 is welded to the first electrode lead-out portion 222 to form a first connecting portion 24.

[0284] The third surface 2112 is a surface of the bottom wall of the assembly groove 2115 facing the electrode assembly 22 in the thickness direction X of the first wall. Figure 7In the embodiment, an assembly groove 2115 is provided on the fourth surface 2114 of the first wall 211, and a second protrusion 2117 protruding from the fifth surface 2116 is formed on the side of the first wall 211 facing the electrode assembly 22 and corresponding to the position of the assembly groove 2115. The third surface 2112 is the surface of the second protrusion 2117 on the side facing the electrode assembly 22 in the thickness direction X of the first wall. If the second protrusion 2117 protruding from the fifth surface 2116 is not provided on the side of the first wall 211 facing the electrode assembly 22, the third surface 2112 and the fifth surface 2116 are the same surface.

[0285] A protrusion 2113 protruding from the third surface 2112 is formed on the bottom wall of the assembly groove 2115 facing the side of the electrode assembly 22 and corresponding to the position of the second groove 2118. That is to say, the second protrusion 2117 is provided with a protrusion 2113 on the side of the first wall facing the electrode assembly 22 and corresponding to the position of the second groove 2118 in the thickness direction X, so that the bottom wall of the second groove 2118 is a structure protruding from the third surface 2112, so that the first wall 211 is a structure in which the protrusion 2113 is welded to the first electrode lead-out portion 222 to form a first connecting portion 24.

[0286] In the present embodiment, a protrusion 2113 protruding from the third surface 2112 is formed on the side of the bottom wall of the second groove 2118 facing the electrode assembly 22 and corresponding to the position of the second groove 2118, and the protrusion 2113 is used to be welded and connected to the first electrode lead-out portion 222 to form the first connection portion 24. The battery cell 20 with such a structure enables the portion of the first wall 211 used for welding and connecting the first electrode lead-out portion 222 to be in full contact with the first electrode lead-out portion 222, which is beneficial to improving the contact effect between the portion of the first wall 211 used for welding and connecting the first electrode lead-out portion 222 and the first electrode lead-out portion 222, thereby reducing the welding difficulty between the first wall 211 and the first electrode lead-out portion 222 on the one hand, and effectively reducing the phenomenon of cold welding when the first wall 211 and the first electrode lead-out portion 222 are welded and assembled, so as to improve the welding quality between the first wall 211 and the first electrode lead-out portion 222.

[0287] According to some embodiments of the present application, see Figure 3 , Figure 4 and Figure 5 As shown, the housing 21 may include a shell 212 and an end cover 213, the shell 212 includes an integrally formed side wall and a bottom wall, the side wall is arranged around the bottom wall, along the thickness direction X of the first wall, one end of the side wall is connected to the bottom wall, and the other end is enclosed to form an opening 2122, the side wall and the bottom wall jointly define a accommodating cavity 2121, the end cover 213 closes the opening 2122, and the bottom wall is the first wall 211.

[0288] Among them, the bottom wall is the first wall 211, that is, the first electrode lead-out portion 222 is connected to one end of the main body 221 facing the bottom wall of the shell 212 in the thickness direction X of the first wall and is welded to the bottom wall of the shell 212 to form a first connecting portion 24, and the sealing part 23 is arranged on the side of the bottom wall of the shell 212 away from the electrode assembly 22.

[0289] Among them, the shell 212 includes integrally formed side walls and bottom walls, that is, the side walls and bottom walls of the shell 212 are structures formed by an integral molding process to form a accommodating cavity 2121 with an opening 2122 inside the shell 212, such as a stamping process or a casting process.

[0290] In this embodiment, by setting the first wall 211 of the outer shell 21 as the bottom wall of the shell 212 arranged opposite to the end cover 213 in the thickness direction X of the first wall, the battery cell 20 adopting this structure can make the first wall 211 that is welded to the first electrode lead-out portion 222 and forms the first connection portion 24 away from the end cover 213, so that there is no direct connection relationship between the first wall 211 and the end cover 213, thereby alleviating the influence of the stress generated when the end cover 213 and the shell 212 are assembled and connected to each other on the first connection portion 24, which is beneficial to improving the welding quality between the first wall 211 and the first electrode lead-out portion 222, thereby improving the production quality of the battery cell 20.

[0291] Of course, the structure of the battery cell 20 is not limited to this. In some embodiments, the battery cell 20 may also be other structures. For example, the outer shell 21 may include a shell 212 and an end cover 213. The shell 212 has a housing chamber 2121 formed inside. The housing chamber 2121 has an opening 2122 formed at one end of the shell 212. The end cover 213 closes the opening 2122. The end cover 213 is a first wall 211, that is, the first electrode lead-out portion 222 is connected to one end of the main body 221 facing the end cover 213 in the thickness direction X of the first wall and is welded to the end cover 213 to form a first connection portion 24, and the sealing member 23 is arranged on the side of the end cover 213 facing away from the electrode assembly 22.

[0292] In this embodiment, by setting the first wall 211 of the outer shell 21 as the end cover 213 of the outer shell 21 for closing the opening 2122 of the shell 212, the battery cell 20 adopting this structure is convenient for assembling the sealing member 23 on the end cover 213, and can reduce the difficulty of welding between the first electrode lead-out portion 222 and the first wall 211, thereby helping to reduce the difficulty of assembling the battery cell 20 and improving the production efficiency of the battery cell 20.

[0293] 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.

[0294] Among them, see Figure 2 As shown, the battery 100 may further include a housing 10 , in which the battery cells 20 are accommodated.

[0295] 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 .

[0296] 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.

[0297] 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.

[0298] 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.

[0299] 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 .

[0300] 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.

[0301] 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.

[0302] The electrical device may be any of the aforementioned devices or systems using the battery cell 20 .

[0303] 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.

[0304] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing having a receiving cavity formed therein, wherein the housing has a first wall; an electrode assembly, accommodated in the accommodation cavity, the electrode assembly comprising a main body and a first electrode lead-out portion, the first electrode lead-out portion being connected to an end of the main body close to the first wall in the thickness direction of the first wall, the first electrode lead-out portion being welded to the first wall to form a first connection portion; as well as The blocking member is arranged on a side of the first wall away from the electrode assembly, the blocking member is sealed and connected to the first wall, and the blocking member covers the first connecting portion along the thickness direction of the first wall.

2. The battery cell according to claim 1, characterized in that: The first wall is provided with an exhaust hole communicating with the accommodating cavity, and the exhaust hole penetrates the first wall along the thickness direction of the first wall; Wherein, the blocking member is configured to release the internal pressure of the battery cell.

3. The battery cell according to claim 2, characterized in that: The blocking member and the first wall together define an exhaust cavity, and the exhaust hole communicates with the exhaust cavity and the accommodating cavity.

4. The battery cell according to claim 3, characterized in that: Along the thickness direction of the first wall, the blocking member has a first surface facing the electrode assembly, and the first surface abuts against the first wall; The first surface is provided with a first groove, and the groove wall surface of the first groove and the first wall together define the exhaust cavity.

5. The battery cell according to claim 4, characterized in that: Along the thickness direction of the first wall, the blocking member has a second surface away from the electrode assembly, and a first protrusion is formed on a side of the blocking member away from the electrode assembly and at a position corresponding to the first groove, and the first protrusion protrudes from the second surface.

6. The battery cell according to claim 4, characterized in that: The blocking member is provided with a pressure relief groove, and the blocking member is configured to be able to be split along at least a portion of the pressure relief groove when the battery cell is depressurized, so as to release the internal pressure of the battery cell; Wherein, along the thickness direction of the first wall, the projection of the pressure relief groove is located inside the first groove.

7. The battery cell according to claim 6, characterized in that: Along the thickness direction of the first wall, the pressure relief groove is arranged on a side of the sealing member away from the electrode assembly.

8. The battery cell according to claim 2, characterized in that: The first electrode lead-out portion includes a first electrode tab and a first current collecting member. Along the thickness direction of the first wall, the first electrode tab is connected to one end of the main body portion close to the first wall. The first current collecting member is disposed between the first electrode tab and the first wall. The first current collecting member is connected to the first electrode tab, and the first current collecting member is welded to the first wall to form the first connecting portion. The first current collecting member is provided with a through hole, the through hole penetrates through two sides of the first current collecting member along the thickness direction of the first wall, and the through hole is communicated with the exhaust hole.

9. The battery cell according to claim 8, characterized in that: Along the thickness direction of the first wall, at least a portion of a projection of at least one of the through holes is located within one of the exhaust holes.

10. The battery cell according to claim 2, characterized in that: The first electrode lead-out portion includes a first electrode tab and a first current collecting member. Along the thickness direction of the first wall, the first electrode tab is connected to one end of the main body portion close to the first wall. The first current collecting member is disposed between the first electrode tab and the first wall. The first current collecting member is connected to the first electrode tab, and the first current collecting member is welded to the first wall to form the first connecting portion. Among them, along the thickness direction of the first wall, the first wall has a third surface facing the electrode assembly, and the first wall has a protrusion protruding from the third surface, the protrusion is welded to the first current collecting member to form the first connecting portion, an exhaust gap is formed between the first current collecting member and the third surface, and the exhaust gap is connected to the exhaust hole.

11. The battery cell according to claim 2, characterized in that: The shell is cylindrical, and the central axis of the shell extends along the thickness direction of the first wall; Wherein, a plurality of exhaust holes are arranged on the first wall, the plurality of exhaust holes include a plurality of first exhaust holes, and the plurality of first exhaust holes are arranged at intervals around the central axis of the shell.

12. The battery cell according to claim 11, characterized in that: A projection of the first exhaust hole in the thickness direction of the first wall is in a sector ring shape extending along the circumference of the housing.

13. The battery cell according to claim 11, characterized in that: The electrode assembly has a central through hole extending in the thickness direction of the first wall, and the central through hole passes through both ends of the main body in the thickness direction of the first wall; The plurality of exhaust holes further include a second exhaust hole, the plurality of first exhaust holes are arranged around the second exhaust hole, and along the thickness direction of the first wall, at least a portion of the projection of the second exhaust hole is located in the central through hole.

14. The battery cell according to claim 1, characterized in that: The first electrode lead-out portion comprises: A first electrode tab connected to an end of the main body portion close to the first wall in the thickness direction of the first wall; The first current collecting member is disposed between the first electrode tab and the first wall along the thickness direction of the first wall, the first current collecting member is connected to the first electrode tab, and the first current collecting member is welded to the first wall to form the first connecting portion.

15. The battery cell according to claim 14, characterized in that: The first current collecting member is welded to the first electrode tab to form a second connection portion.

16. The battery cell according to claim 15, characterized in that: Along the thickness direction of the first wall, a projection of the second connecting portion does not overlap with a projection of the first connecting portion.

17. The battery cell according to claim 15, characterized in that: The first wall is provided with an exhaust hole communicating with the accommodating cavity, and the exhaust hole penetrates the first wall along the thickness direction of the first wall; Wherein, along the thickness direction of the first wall, a projection of at least one of the second connecting parts is located within one of the exhaust holes.

18. The battery cell according to claim 15, characterized in that: The first current collecting member is welded to the first wall to form a plurality of first connection portions, and the first current collecting member is welded to the first electrode tab to form a plurality of second connection portions; The plurality of first connection portions and the plurality of second connection portions are alternately and spaced apart along the circumferential direction of the first current collecting member.

19. The battery cell according to claim 15, characterized in that: The first pole lug is a cylindrical structure with a central axis extending along the thickness direction of the first wall, and the second connecting portion extends along the radial direction of the first pole lug; Wherein, along the radial direction of the first pole lug, the size of the first pole lug is L1, the size of the second connecting portion is L2, and 0.5≤L2 / L1≤1.

20. The battery cell according to any one of claims 1 to 19, characterized in that: Along the thickness direction of the first wall, the first wall has a fourth surface facing away from the electrode assembly, and the fourth surface is the surface of the first wall farthest from the electrode assembly; The fourth surface is provided with an assembly groove, the first electrode lead-out portion is welded to the groove bottom wall of the assembly groove to form the first connection portion, and at least a portion of the blocking member is disposed in the assembly groove.

21. The battery cell according to claim 20, characterized in that: Along the thickness direction of the first wall, the blocking member does not exceed the fourth surface.

22. The battery cell according to claim 20, characterized in that: Along the thickness direction of the first wall, the first wall also has a fifth surface facing the electrode assembly, and a second protrusion is formed on one side of the first wall facing the electrode assembly and corresponding to the position of the assembly groove, and the second protrusion is protruding on the fifth surface.

23. The battery cell according to claim 20, characterized in that: The outer peripheral surface of the blocking piece is welded to the groove side surface of the assembly groove to form a third connecting portion, and the third connecting portion is an annular structure.

24. The battery cell according to claim 23, characterized in that: The assembly groove includes a first groove and a second groove, the first groove is arranged on the fourth surface, the second groove is arranged on the groove bottom surface of the first groove, and the first electrode lead-out portion is welded to the groove bottom wall of the second groove to form the first connecting portion; Wherein, the outer peripheral surface of the blocking member is welded to the groove side surface of the second groove to form the third connecting portion.

25. The battery cell according to claim 24, characterized in that: Along the thickness direction of the first wall, the third connection portion does not exceed the fourth surface.

26. The battery cell according to claim 24, characterized in that: Along the thickness direction of the first wall, the blocking member has a second surface facing away from the electrode assembly, the second surface is connected to the outer peripheral surface of the blocking member, and the second surface is coplanar with the bottom surface of the first groove.

27. The battery cell according to claim 24, characterized in that: Along the thickness direction of the first wall, the blocking member abuts against the bottom surface of the second groove.

28. The battery cell according to claim 20, characterized in that: A second groove is provided on the bottom surface of the assembly groove, and along the thickness direction of the first wall, the projection of the first connecting portion is located in the second groove.

29. The battery cell according to claim 28, characterized in that: Along the thickness direction of the first wall, the blocking member covers the second groove.

30. The battery cell according to claim 28, characterized in that Along the thickness direction of the first wall, the bottom wall of the assembly groove has a third surface facing the electrode assembly, and a protrusion protruding from the third surface is formed on the side of the bottom wall of the assembly groove facing the electrode assembly and corresponding to the position of the second groove, and the protrusion is welded to the first electrode lead-out portion to form the first connecting portion.

31. The battery cell according to claim 1, characterized in that The housing comprises: A housing, comprising an integrally formed side wall and a bottom wall, wherein the side wall is disposed around the bottom wall, and along the thickness direction of the first wall, one end of the side wall is connected to the bottom wall, and the other end is enclosed to form an opening, and the side wall and the bottom wall jointly define the accommodating cavity; an end cap for closing the opening; Wherein, the bottom wall is the first wall.

32. The battery cell according to claim 1, characterized in that The housing comprises: A shell body, wherein the accommodating cavity is formed inside, and the accommodating cavity is formed with an opening at one end of the shell body; an end cap for closing the opening; Wherein, the end cover is the first wall.

33. A battery, characterized in that: Comprising the battery cell according to any one of claims 1-32.

34. An electrical device, characterized in that: The invention comprises a battery cell as claimed in any one of claims 1 to 32, wherein the battery cell is used to provide electrical energy.

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