Battery cell, battery and electric device

Abstract

A battery cell (6), a battery (2) and an electric device. The battery cell (6) comprises a casing (20), an electrode assembly (10) and a first electrode terminal (30), wherein the casing (20) comprises a first wall portion (20a); the electrode assembly (10) is accommodated in the casing (20), and the electrode assembly (10) comprises a first tab (12); and the first electrode terminal (30) is arranged on the first wall portion (20a) and is electrically connected to the first tab (12), the first electrode terminal (30) comprises a first terminal portion (31) located on the outer side of the first wall portion (20a), and the first terminal portion (31) is configured to connect to a first busbar component (7a) of a battery (2) and exchange heat with a heat exchange member (9) of the battery (2).

Description

Battery cell, battery and electric device TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, and more particularly, to a battery cell, a battery and an electric device. BACKGROUND

[0002] Battery cells are widely used in electronic devices, such as mobile phones, notebook computers, electric vehicles, electric cars, electric planes, electric ships, electric toy cars, electric toy ships, electric toy planes and electric tools, etc.

[0003] In the development of battery technology, how to improve the cycle performance of battery cells is a research direction in the field of battery technology.

[0004] SUMMARY

[0005] The present application provides a battery cell, a battery and an electric device, which can improve the cycle performance of the battery cell.

[0006] In a first aspect, the embodiments of the present application provide a battery cell, comprising a shell, an electrode assembly and a first electrode terminal. The shell comprises a first wall portion. The electrode assembly is accommodated in the shell, and the electrode assembly comprises a first tab. The first electrode terminal is arranged on the first wall portion and electrically connected to the first tab, and the first electrode terminal comprises a first terminal portion located outside the first wall portion, the first terminal portion being used for connecting a first busbar component of a battery and exchanging heat with a heat exchange member of the battery.

[0007] The first terminal portion can exchange heat with the heat exchange member, thereby improving the heat dissipation capacity of the battery cell, reducing the temperature rise of the battery cell, improving the cycle performance and cycle life of the battery cell, and reducing the risk of thermal runaway of the battery cell during rapid charging. The first electrode terminal is connected to the first tab, and the heat of the first tab can also be conducted to the heat exchange member through the first terminal portion, thereby reducing the temperature rise of the electrode assembly and improving the cycle performance and cycle life of the battery cell. The first terminal portion can simultaneously play the roles of heat dissipation and current transmission, which helps to shorten the heat transfer path between the heat source and the heat exchange member and improve the heat dissipation efficiency.

[0008] In some embodiments, the first terminal portion comprises a first part and a second part, the first part being used for connecting the first busbar component, and the second part being used for exchanging heat with the heat exchange member. The first busbar component and the heat exchange member act on different parts of the first terminal portion, respectively, which can reduce the risk of interference between the first busbar component and the heat exchange member.

[0009] In some embodiments, the first part is configured to at least partially overlap and connect with the first busbar component in the thickness direction of the first wall portion, and the second part is configured to at least partially overlap with the heat exchange member in the thickness direction.

[0010] The first portion is arranged in the thickness direction of the first bus member, which can increase the connection strength and the flow area between the first portion and the first bus member, and reduce heat generation. The second portion is arranged in the thickness direction of the heat exchange member, which can increase the heat exchange area of the second portion and the heat exchange member, and improve the heat exchange efficiency. The first bus member and the heat exchange member can share the space in the thickness direction, thereby improving the space utilization in the thickness direction and improving the energy density of the battery.

[0011] In some embodiments, the thickness of the first portion is greater than the thickness of the second portion. The first portion has a greater thickness than the second portion, and the first portion is less likely to be melted through when welded with the first bus member, thereby improving the reliability of the battery monomer. The second portion does not need to be welded with the first bus member, and can have a smaller thickness, thereby reducing the volume and weight of the first electrode terminal and improving the energy density of the battery monomer.

[0012] In some embodiments, the first portion extends beyond the second portion in a direction away from the first wall portion. In the thickness direction of the first wall portion, the surface of the second portion away from the first wall portion is closer to the first wall portion than the surface of the second portion away from the first wall portion, thereby reserving more space on the side of the second portion away from the first wall portion to facilitate the arrangement of the heat exchange member and improve the space utilization.

[0013] In some embodiments, the side of the first terminal portion away from the first wall portion has a first recess, and the second portion is a bottom wall of the first recess. By providing the first recess, space can be provided for the heat exchange member, thereby improving the space utilization in the thickness direction of the first wall portion.

[0014] In some embodiments, in the thickness direction of the first wall portion, the depth of the first recess is 0.1mm-2mm. Limiting the depth of the first recess to be greater than or equal to 0.1mm can provide more space for other components and improve the space utilization. Limiting the depth of the first recess to be less than or equal to 2mm can reduce the loss of thermal conductivity of the second portion due to thinning, to some extent, to balance the heat exchange efficiency of the second portion and the heat exchange member.

[0015] In some embodiments, the first portion and the second portion are arranged in a first direction, the size of the first portion in a second direction is less than the size of the second portion in the second direction, and the thickness direction of the first wall portion, the first direction, and the second direction are perpendicular to each other. The second portion has a larger size in the second direction, which can increase the heat exchange area of the second portion and the heat exchange member, further improve the heat exchange efficiency, and improve the cycle performance of the battery monomer.

[0016] In some embodiments, the first portion and the second portion are spaced apart along a first direction, and the first direction is perpendicular to a thickness direction of the first wall portion. The first portion and the second portion can be independently formed, which facilitates the processing of the part and eliminates the size limitation caused by the manufacturing capacity, and provides a larger area of the second portion, thereby improving the heat exchange effect.

[0017] In some embodiments, the first portion and the second portion are arranged along a first direction, and the first direction is perpendicular to a thickness direction of the first wall portion. In the first direction, the size of the second portion is greater than the size of the first portion. The second portion has a size greater than the first portion in the first direction, which can increase the heat exchange area between the second portion and the heat exchange member, improve the heat exchange efficiency, reduce the temperature rise inside the battery cell, and improve the cycle performance of the battery cell.

[0018] In some embodiments, the surface of the first terminal portion away from the first wall portion is configured to be connected with the heat exchange member.

[0019] In some embodiments, the surface of the first terminal portion away from the first wall portion includes a first region and a second region, the first region is configured to be connected with the first current collecting component, and the second region is configured to be arranged opposite to the heat exchange member in the thickness direction of the first wall portion. The first current collecting component and the heat exchange member act on the first region and the second region, respectively, which can reduce the risk of interference between the first current collecting component and the heat exchange member, and reduce the superposition of the first current collecting component and the heat exchange member in the thickness direction, thereby improving the space utilization.

[0020] In some embodiments, the first region and the second region are spaced apart, so as to reduce the risk of interference between the first current collecting component and the heat exchange member caused by assembly errors.

[0021] In some embodiments, the area of the second region is greater than the area of the first region. The larger area of the second region can improve the heat exchange efficiency between the heat exchange member and the first terminal portion, reduce the temperature rise of the first terminal portion, and improve the cycle performance and reliability of the battery cell.

[0022] In some embodiments, the ratio of the area of the first region to the projection area of the first terminal portion in the thickness direction is greater than or equal to 1.5%, so that the first terminal portion and the first current collecting component have a larger connection area and a higher connection strength, thereby improving the current carrying capacity between the first terminal portion and the first current collecting component, reducing heat generation, and reducing the temperature rise.

[0023] In some embodiments, the ratio of the area of the second region to the projection area of the first terminal portion in the thickness direction is greater than or equal to 10%, so that the first terminal portion and the heat exchange member have a larger heat exchange area, thereby improving the heat exchange efficiency between the first terminal portion and the heat exchange member, reducing the temperature rise of the first terminal portion and the temperature rise of the electrode assembly, and improving the cycle performance of the battery cell.

[0024] In some embodiments, the first wall portion is provided with a first electrode lead-out hole. The first electrode terminal further includes a second terminal portion and a third terminal portion, the second terminal portion is located inside the first wall portion and electrically connected to the first tab, at least part of the third terminal portion is accommodated in the first electrode lead-out hole, and the third terminal portion connects the second terminal portion and the first terminal portion. In the thickness direction of the first wall portion, part of the first wall portion is located between the first terminal portion and the second terminal portion.

[0025] In some embodiments, the second terminal portion and the third terminal portion are integrally formed, which can improve the connection strength between the second terminal portion and the third terminal portion, reduce the resistance, and improve the overcurrent capacity.

[0026] In some embodiments, the first terminal portion is provided with a first through hole, the first through hole penetrates the first terminal portion in the thickness direction of the first wall portion. Part of the third terminal portion is accommodated in the first through hole and connected to the first terminal portion. During assembly, the third terminal portion can be first passed through the first electrode lead-out hole and the first through hole, and then the third terminal portion is connected to the first terminal portion. By providing the first through hole, the assembly process can be simplified.

[0027] In some embodiments, in the thickness direction, the end of the third terminal portion away from the second terminal portion does not exceed the first through hole, so as to reduce the risk of interference of the third terminal portion with the connection of the first terminal portion and the first bus member, or reduce the risk of interference of the third terminal portion with the connection of the first terminal portion and the heat exchange member.

[0028] In some embodiments, the third terminal portion is configured such that the third terminal portion does not overlap the heat exchange member in the thickness direction. By avoiding the third terminal portion from being arranged close to the heat exchange member, the risk of interference of the third terminal portion with the heat exchange member can be reduced, and the flatness of the heat exchange interface between the first terminal portion and the heat exchange member can be improved.

[0029] In some embodiments, the first terminal portion includes a first edge and a second edge arranged opposite in a first direction, the first direction being parallel to the length direction of the first wall portion. In the first direction, the minimum distance between the axis of the first through hole and the first edge is equal to the minimum distance between the axis of the first through hole and the second edge. By centrally arranging the first through hole and the third terminal portion, the structural strength of the first electrode terminal can be improved, and the risk of deformation of the first terminal portion can be reduced.

[0030] In some embodiments, the first terminal portion includes a first edge and a second edge oppositely arranged along a first direction, the first direction being parallel to a length direction of the first wall portion. In the first direction, a minimum distance between an axis of the first through hole and the first edge is smaller than a minimum distance between an axis of the first through hole and the second edge, a portion of the first terminal portion between the first edge and the first through hole is used to connect with the first busbar component, and a portion of the first terminal portion between the second edge and the first through hole is used to exchange heat with the heat exchange member. By designing the first through hole to be eccentric, a larger area can be reserved for heat exchange with the heat exchange member, thereby improving the heat exchange efficiency. The embodiments of the present application can also reduce the distance between the third terminal portion and the first busbar component, shorten the conductive path, reduce the resistance, and reduce heat generation.

[0031] In some embodiments, the first electrode terminal includes a plurality of third terminal portions arranged at intervals. By arranging a plurality of third terminal portions, the overcurrent capacity can be improved, heat generation can be reduced, and the structural strength of the first electrode terminal can be improved, thereby improving the stability of the connection between the first electrode terminal and the first wall portion.

[0032] In some embodiments, the first terminal portion includes a first portion and a second portion arranged at intervals along a first direction, the first direction being perpendicular to a thickness direction of the first wall portion. The first portion is connected to the second terminal portion through at least one third terminal portion, and the second portion is connected to the second terminal portion through at least one third terminal portion. By connecting the first portion to the third terminal portion, the stability of the first portion can be improved, and when the battery cell is subjected to external impact, the third terminal portion can limit the deformation of the first portion, thereby reducing the risk of failure of the connection between the first portion and the first busbar component. By connecting the second portion to the third terminal portion, when the battery cell is subjected to external impact, the third terminal portion can limit the deformation of the second portion, thereby reducing the stability of the heat exchange interface between the second portion and the heat exchange member.

[0033] In some embodiments, the first terminal portion includes a first edge and a second edge oppositely arranged along a first direction, the first direction being parallel to a length direction of the first wall portion. The first terminal portion is provided with two first through holes arranged at intervals along the first direction, and two third terminal portions are respectively provided in the two first through holes and connected to the first terminal portion. In the first direction, a distance between the first edge and an axis of the first through hole close to the first edge is D1, a distance between the second edge and an axis of the first through hole close to the second edge is D2, and a distance between the axes of the two first through holes is D3. D1 / D2 is 0.9-1.1, and (D1+D2) / D3 is 0.9-1.1.

[0034] From the thickness direction, the two third terminal portions are approximately symmetrically arranged, which can improve the stability of the first terminal portion and improve the structural strength of the first electrode terminal.

[0035] In some embodiments, a cross section of the third terminal portion perpendicular to a thickness direction of the first wall portion is circular, elliptical, or track-shaped.

[0036] In some embodiments, the first tab is welded to the second terminal portion and forms a first welding mark. Directly welding the first tab to the second terminal portion can shorten a conductive path between the first tab and the second terminal portion, reduce the resistance, and reduce heat generation of the first tab and the second terminal portion.

[0037] In some embodiments, the first welding mark is configured to at least partially overlap the heat exchange member in the thickness direction of the first wall portion. The first welding mark generates heat when a current passes through the first welding mark. The embodiments of the present application can reduce the distance between the first welding mark and the heat exchange member, improve the heat dissipation efficiency of the first welding mark, and reduce the temperature rise of the first welding mark.

[0038] In some embodiments, a projected area of the first terminal portion in the thickness direction of the first wall portion is greater than a projected area of the second terminal portion. The first terminal portion can have a larger area than the second terminal portion, which can improve the heat dissipation efficiency of the first terminal portion; the second terminal portion can have a smaller area than the first terminal portion, thereby saving internal space of the shell and improving the energy density of the battery monomer, under the premise that the overcurrent area meets the requirements.

[0039] In some embodiments, a projected area of the second terminal portion in the thickness direction of the first wall portion is 0.2-0.5 times a projected area of the first wall portion.

[0040] The ratio of the projected area of the second terminal portion to the projected area of the first wall portion is greater than or equal to 0.2, and the second terminal portion and the first tab can have a larger connection area and overcurrent area, thereby reducing the resistance, reducing heat generation of the second terminal portion and the first tab, and reducing the temperature rise of the battery monomer. The ratio of the projected area of the second terminal portion to the projected area of the first wall portion is less than or equal to 0.5, which can reserve installation space for other components in the shell, reduce the risk of interference and short circuit between the second terminal portion and other components, and improve the reliability of the battery monomer.

[0041] In some embodiments, a projected area of the first terminal portion in the thickness direction of the first wall portion is 0.2-0.5 times a projected area of the first wall portion. The ratio of the projected area of the first terminal portion to the projected area of the first wall portion is greater than or equal to 0.2, and the first terminal portion can reserve a larger area for heat exchange with the heat exchange member, thereby improving the heat exchange efficiency and improving the cycle performance and reliability of the battery monomer. The ratio of the projected area of the first terminal portion to the projected area of the first wall portion is less than or equal to 0.5, which can reserve installation space for other components of the battery monomer.

[0042] In some embodiments, the electrode assembly further includes a second tab, the first tab and the second tab being opposite in polarity. The battery cell further includes a second electrode terminal disposed on the housing, the second electrode terminal being electrically connected to the second tab.

[0043] In some embodiments, the second electrode terminal includes a fourth terminal portion located on the outer side of the housing, the fourth terminal portion being configured to connect to the second busbar of the battery and exchange heat with the heat exchange member. During the cycling of the battery, both the first terminal portion and the fourth terminal portion can exchange heat with the heat exchange member, thereby further improving the heat dissipation capability of the battery cell, reducing the temperature rise of the battery cell, improving the cycling performance and cycling life of the battery cell, and reducing the risk of thermal runaway of the battery cell during rapid charging. The second electrode terminal is connected to the second tab, and the heat of the second tab can also be conducted to the heat exchange member through the fourth terminal portion, thereby reducing the temperature rise of the electrode assembly and improving the cycling performance and cycling life of the battery cell. The fourth terminal portion can simultaneously serve as a heat dissipation and current transmission, which helps to shorten the heat transfer path between the heat source and the heat exchange member and improve the heat dissipation efficiency.

[0044] In some embodiments, the second electrode terminal is disposed on the first wall portion. The surface of the first terminal portion away from the first wall portion includes a first region and a second region, the first region being configured to overlap and connect to the first busbar in the thickness direction of the first wall portion. The surface of the fourth terminal portion away from the first wall portion includes a third region and a fourth region, the third region being configured to overlap and connect to the second busbar in the thickness direction. The second region and the fourth region are configured to overlap the heat exchange member in the thickness direction.

[0045] In some embodiments, the second region, the first region, the third region, and the fourth region are sequentially and spacedly arranged along a first direction. The first direction is perpendicular to the thickness direction. The second region and the fourth region are adjacently arranged along the first direction, and a same heat exchange member can exchange heat with both the second region and the fourth region, thereby simplifying the structure of the battery.

[0046] In some embodiments, the first region, the second region, the fourth region, and the third region are sequentially and spacedly arranged along a first direction. The first direction is perpendicular to the thickness direction. When a plurality of battery cells are arranged along the first direction, the second region of one battery cell is adjacent to the fourth region of another battery cell, and a same heat exchange member can exchange heat with both the two battery cells, thereby simplifying the structure of the battery.

[0047] In some embodiments, the second electrode terminal includes a fourth terminal portion located on the outer side of the housing. The projection area of the first terminal portion along the thickness direction thereof is greater than the projection area of the fourth terminal portion along the thickness direction thereof. Arranging the first terminal portion, which exchanges heat with the heat exchange member, to be larger can increase the heat exchange area and improve the heat exchange efficiency. The fourth terminal portion can have a smaller area, thereby saving space and improving the energy density of the battery cell.

[0048] In some embodiments, the first terminal portion has a projected area in the thickness direction of the first terminal portion that is 1.2-5 times the projected area in the thickness direction of the fourth terminal portion, or optionally, 2-3 times the projected area in the thickness direction of the fourth terminal portion. The embodiments of the present application can balance the heat exchange efficiency and the flow capacity to some extent.

[0049] In some embodiments, the housing is provided with a first electrode lead-out hole and a second electrode lead-out hole. The first electrode terminal further includes a second terminal portion and a third terminal portion, the second terminal portion is located inside the first wall portion and is electrically connected to the first tab, at least part of the third terminal portion is accommodated in the first electrode lead-out hole, and the third terminal portion connects the second terminal portion and the first terminal portion. The second electrode terminal further includes a fourth terminal portion, a fifth terminal portion and a sixth terminal portion, the fourth terminal portion is located outside the housing, the fifth terminal portion is located inside the housing and is electrically connected to the second tab, at least part of the sixth terminal portion is accommodated in the second electrode lead-out hole, and the sixth terminal portion connects the fifth terminal portion and the fourth terminal portion. The second terminal portion has a projected area in the thickness direction of the second terminal portion that is greater than the projected area in the thickness direction of the fifth terminal portion. The second terminal portion can have a larger flow area than the fifth terminal portion, thereby reducing the heat generation of the second terminal portion. The first terminal portion has a larger area to achieve heat exchange with the heat exchange member. The second terminal portion is provided to have a larger area, which can reduce the strength difference between the first terminal portion and the second terminal portion, reduce the deformation of the second terminal portion when the battery cell is subjected to external impact, and improve the stability of the fixation of the first electrode terminal and the first wall portion.

[0050] In some embodiments, the second terminal portion has a projected area in the thickness direction of the second terminal portion that is 1.2-5 times the projected area in the thickness direction of the fifth terminal portion, or optionally, 2-3 times the projected area in the thickness direction of the fifth terminal portion. The embodiments of the present application can balance the flow capacity of the first electrode terminal and the flow capacity of the second electrode terminal to some extent, and improve the cycle performance of the battery cell.

[0051] In some embodiments, the second electrode terminal is arranged on the first wall portion, and the second electrode terminal includes a fourth terminal portion located outside the first wall portion. In the thickness direction of the first wall portion, the first terminal portion has a projected area S1, the fourth terminal portion has a projected area S2, and the first wall portion has a projected area S3. S1, S2 and S3 satisfy: 0.2≤(S1+S2) / S3≤0.8; or optionally, 0.3≤(S1+S2) / S3≤0.5.

[0052] The (S1+S2) / S3 is greater than or equal to 0.2, the first terminal part and the fourth terminal part have a larger area, the heat dissipation capacity and overcurrent capacity of the first electrode terminal and the heat dissipation capacity and overcurrent capacity of the second electrode terminal are improved, and the cycle performance of the battery cell is improved. The (S1+S2) / S3 is less than or equal to 0.8, installation space is reserved for other components, the distance between the first terminal part and the second terminal part is maintained, and the risk of short circuit is reduced.

[0053] In some embodiments, the shell includes a second wall part opposite to the first wall part, and the second electrode terminal is arranged on the second wall part. In the thickness direction of the first wall part, the projection area of the first terminal part is S1, and the projection area of the first wall part is S3. S1 and S3 satisfy: 0.2≤S1 / S3≤0.8; optionally, 0.3≤S1 / S3≤0.5. The S1 / S3 is greater than or equal to 0.3, the first terminal part has a larger area, the heat dissipation capacity and overcurrent capacity of the first electrode terminal are improved, and the cycle performance of the battery cell is improved. The S1 / S3 is less than or equal to 0.8, installation space is reserved for other components, and the influence of the first terminal part on the energy density of the battery cell is reduced.

[0054] In some embodiments, the second electrode terminal is arranged on the first wall part, and the second electrode terminal includes a fourth terminal part outside the first wall part. In the thickness direction of the first wall part, the fourth terminal part does not overlap the heat exchange member. When the heat exchange efficiency between the heat exchange member and the first terminal part meets the demand, the heat exchange member can not exchange heat with the fourth terminal part, which can reduce the volume of the heat exchange member, reduce the layout difficulty of the heat exchange member, and improve the energy density of the battery.

[0055] In some embodiments, the shell includes a second wall part, and the battery cell includes a pressure relief mechanism arranged on the second wall part. Arranging the pressure relief mechanism on the second wall part can reserve more space on the first wall part for installing the first electrode terminal, so that the first terminal part has a larger exposed area, the heat dissipation capacity of the first terminal part is improved, the temperature rise of the first terminal part is reduced, and the cycle performance and cycle life of the battery cell are improved.

[0056] In some embodiments, the first electrode terminal is a positive electrode terminal, and the material of the first electrode terminal includes aluminum. Aluminum has good thermal conductivity and electrical conductivity, and the use of an aluminum first electrode terminal can reduce the heat generation of the first electrode terminal and improve the heat exchange efficiency between the first electrode terminal and the heat exchange member.

[0057] In some embodiments, the first wall part is provided with an electrolyte injection hole. In the production process of the battery cell, electrolyte can be injected into the shell through the electrolyte injection hole.

[0058] In some embodiments, the shell includes a housing and an end cover, the housing has an opening, and the end cover is connected to the housing and covers the opening. The end cover is the first wall portion. The end cover generally has a greater thickness than the housing. By arranging the first electrode terminal on the end cover, the connection strength between the first electrode terminal and the end cover can be improved, the stability of the first electrode terminal can be improved, and the risk of the first electrode terminal being offset can be reduced.

[0059] In a second aspect, the embodiments of the present application provide a battery, which includes the battery cell of any of the embodiments of the first aspect, a first current collecting component, and a heat exchange member. The first current collecting component is connected to the first terminal portion. At least part of the heat exchange member is located on the side of the first wall portion away from the electrode assembly and exchanges heat with the first terminal portion.

[0060] In some embodiments, in the thickness direction of the first wall portion, part of the first terminal portion is located between the heat exchange member and the first wall portion.

[0061] In some embodiments, the battery further includes a box body. The battery cell and the first current collecting component are accommodated in the box body, and the heat exchange member is arranged outside the box body.

[0062] In a third aspect, the embodiments of the present application provide a power utilization device, which includes the battery of any of the embodiments of the second aspect, and the battery is used to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0063] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of the drawings.

[0064] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0065] FIG. 2 is a schematic diagram of a battery provided by some embodiments of the present application;

[0066] FIG. 3 is a schematic diagram of part of the structure of a battery provided by some embodiments of the present application;

[0067] FIG. 4 is a partial cross-sectional schematic diagram of a battery provided by some embodiments of the present application;

[0068] FIG. 5 is a structural schematic diagram of a battery provided by some embodiments of the present application;

[0069] FIG. 6 is an exploded schematic diagram of the battery cell shown in FIG. 5;

[0070] FIG. 7 is an enlarged schematic diagram of the part of FIG. 4 at block A;

[0071] FIG. 8 is an enlarged schematic diagram of the part of FIG. 4 at block B;

[0072] Fig. 9 is a structural schematic view of an end cover assembly of a battery cell according to some embodiments of the present application;

[0073] Fig. 10 is a top view of the end cover assembly shown in Fig. 9;

[0074] Fig. 11 is a bottom view of the end cover assembly shown in Fig. 9;

[0075] Fig. 12 is a structural schematic view of an end cover assembly according to some other embodiments of the present application;

[0076] Fig. 13 is a top view of the end cover assembly shown in Fig. 12;

[0077] Fig. 14 is a structural schematic view of an end cover assembly of a battery cell according to some other embodiments of the present application;

[0078] Fig. 15 is a structural schematic view of an end cover assembly of a battery cell according to some other embodiments of the present application;

[0079] Fig. 16 is a structural schematic view of an end cover assembly of a battery cell according to some other embodiments of the present application;

[0080] Fig. 17 is a sectional view of the end cover assembly shown in Fig. 16;

[0081] Fig. 18 is a top view of an end cover assembly of a battery cell according to some other embodiments of the present application;

[0082] Fig. 19 is a structural schematic view of an end cover assembly of a battery cell according to some other embodiments of the present application;

[0083] Fig. 20 is a structural schematic view of an end cover assembly of a battery cell according to some other embodiments of the present application;

[0084] Fig. 21 is a simplified schematic view of a battery cell according to some other embodiments of the present application;

[0085] Fig. 22 is a sectional view of a battery according to some embodiments of the present application.

[0086] In the drawings, the drawings are not drawn according to the actual scale;

[0087] Explanation of reference numerals:

[0088] 1, vehicle; 2, battery; 3, controller; 4, motor; 5, case; 5a, first case portion; 5b, second case portion; 6, battery cell; 7, bus member; 7a, first bus member; 7b, second bus member; 8, heat exchange plate; 9, heat exchange member; 9a, thermally conductive adhesive;

[0089] 10, electrode assembly; 11, electrode main body; 12, first tab; 13, second tab;

[0090] 20, housing; 20a, first wall portion; 20b, second wall portion; 21, case; 22, end cover; 221, first electrode lead-out hole; 222, second electrode lead-out hole; 223, electrolyte injection hole;

[0091] 30, first electrode terminal; 31, first terminal portion; 311, first portion; 312, second portion; 313, first recess; 314, first through-hole; 31a, first area; 31b, second area; 31c, first edge; 31d, second edge; 32, second terminal portion; 33, third terminal portion;

[0092] 40, second electrode terminal; 41, fourth terminal portion; 411, third portion; 412, fourth portion; 413, second recess; 414, second through-hole; 41a, third area; 41b, fourth area; 41c, third edge; 41d, fourth edge; 41e, first plate; 41f, second plate; 42, fifth terminal portion; 43, sixth terminal portion;

[0093] 50, end cover assembly;

[0094] 60, pressure relief mechanism;

[0095] 70, sealing sheet; 80a, first solder mark; 80b, second solder mark;

[0096] X, first direction; Y, second direction; Z, thickness direction. DETAILED DESCRIPTION

[0097] In order to make the objects, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0098] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the specification herein is for describing particular embodiments only and is not intended to be limiting of the application. Unless otherwise defined, all terms used in disclosing the application, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. It will be further understood that terms used in the description of the disclosed subject matter should not be interpreted as identifying key

[0099] Reference throughout this application to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily all directed to the same embodiment, nor are they necessarily all mutually exclusive or alternative embodiments.

[0100] In the description of the application, it is necessary to explain that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "attaching" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0101] The term "and / or" in this application is only a description of the association relationship between the associated objects, which means that there can be three kinds of relationships, for example, A and / or B can mean that there are three cases of A alone, A and B together, and B alone. In addition, the character " / " in this application generally represents that the front and rear associated objects have an "or" relationship.

[0102] In the embodiments of the application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length and width of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length and width of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0103] "Ranges" disclosed herein are defined, for each specific range of values, by a lower limit and an upper limit, the lower and upper limits of which define the boundaries in the specific range. Ranges can be inclusive or exclusive of the endpoints, and are arbitrarily combinable, i.e., any lower limit can be combined with any upper limit to create a range. For example, if a range of 60 to 120 and a range of 80 to 110 are listed, it is understood that a range of 60 to 110 and a range of 80 to 120 are also contemplated. Furthermore, if a minimum range value of 1 and 2 are listed, and if a maximum range value of 3, 4, and 5 are listed, then the following ranges are all contemplated: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4, and 2 to 5. In this application, unless otherwise indicated, a numerical range "a to b" indicates a range of values that includes any and all combinations of sub-ranges between of the values of "a" and "b," where "a" and "b" are both real numbers. For example, the numerical range "0 to 5" indicates that all real numbers between 0 and 5 have been listed herein, and "0 to 5" is merely a shorthand for listing all of the sub-ranges between 0 and 5. Additionally, when a parameter is stated to be an integer ≥ 2, it is equivalent to disclose that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0104] "Plural" as used herein means two or more (including two).

[0105] At present, from the development of market situation, the application of battery is more and more extensive. The battery is not only applied to the energy storage power supply system of hydropower, thermal power, wind power and solar power station, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, aerospace and other fields. With the continuous expansion of the application field of battery, the market demand is also increasing.

[0106] The battery generally refers to a single physical module including a plurality of battery monomers to provide higher voltage and capacity. The battery monomer can be the smallest unit constituting the battery.

[0107] With the development of the battery, especially widely used in daily life, users hope that the battery can complete the charging faster to adapt to the needs of fast-paced modern life. However, in the process of fast charging, the heat generation of the battery monomer increases, so that the battery monomer is maintained in a high temperature interval during the whole charging process, which affects the cycle performance and cycle life of the battery, and aggravates the risk of thermal runaway of the battery.

[0108] In view of this, the battery monomer provided by the embodiments of the present application improves the heat exchange efficiency by exchanging heat between the electrode terminal of the battery monomer and the heat exchange member, reduces the risk of thermal runaway of the battery monomer in the process of fast charging, reduces the temperature rise of the battery monomer, and improves the cycle performance and cycle life of the battery monomer.

[0109] The battery described in the embodiments of the present application is suitable for a power consumption device using the battery. The power consumption device can be a device using the battery as a power source or various energy storage systems using the battery as an energy storage element. The power consumption device can be, but is not limited to, a mobile phone, a tablet, a notebook computer, an electric toy, an electric tool, an electric vehicle, an electric automobile, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, such as a game console, an electric automobile toy, an electric ship toy, and an electric aircraft toy, and the spacecraft can include an airplane, a rocket, a space shuttle, a spacecraft, and the like.

[0110] The following embodiments are described for convenience by taking a vehicle as an example of the power consumption device.

[0111] FIG. 1 is a structural schematic diagram of a vehicle provided by some embodiments of the present application.

[0112] As shown in FIG. 1, the vehicle 1 is internally provided with a battery 2, which can be arranged at the bottom, the head, or the tail of the vehicle 1. The battery 2 can be used for power supply of the vehicle 1, for example, the battery 2 can be used as an operating power source of the vehicle 1.

[0113] The vehicle 1 can further include a controller 3 and a motor 4, the controller 3 being used to control the battery 2 to supply power to the motor 4, for example, for the working power demand of the vehicle 1 during starting, navigation, and driving.

[0114] In some embodiments of the present application, the battery 2 can not only be used as an operating power source of the vehicle 1, but also be used as a driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0115] FIG. 2 is a schematic diagram of a battery provided by some embodiments of the present application.

[0116] Referring to FIG. 2, in some embodiments, the battery 2 includes a box body 5 and a plurality of battery monomers 6 contained in the box body 5.

[0117] The battery monomer 6 can be a secondary battery monomer, which refers to a battery monomer 6 that can be activated by charging after discharging to continue to be used.

[0118] Exemplarily, the battery monomer 6 can be a lithium ion battery monomer, a sodium ion battery monomer, a sodium lithium ion battery monomer, a lithium metal battery monomer, a sodium metal battery monomer, a lithium sulfur battery monomer, a magnesium ion battery monomer, a nickel hydrogen battery monomer, a nickel cadmium battery monomer, a lead storage battery monomer, and the like.

[0119] As an example, the battery cell 6 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes, the prismatic battery cell including a square battery cell, a blade battery cell, a multi-prismatic battery cell, for example, a hexagonal battery cell, etc.

[0120] The plurality of battery cells 6 can be connected in series, in parallel, or in a mixed manner, the mixed manner referring to that the plurality of battery cells 6 are connected in series and in parallel at the same time. The plurality of battery cells 6 can be directly connected in series, in parallel, or in a mixed manner, and the whole of the plurality of battery cells 6 is accommodated in the box 5; of course, the plurality of battery cells 6 can be first connected in series, in parallel, or in a mixed manner to form a battery module, and the plurality of battery modules are connected in series, in parallel, or in a mixed manner to form a whole, which is accommodated in the box 5.

[0121] In some embodiments, the box 5 is used to accommodate the battery cell 6, and the box 5 can be of various structures.

[0122] In some embodiments, the box 5 can include a first box part 5a and a second box part 5b, the first box part 5a and the second box part 5b are overlapped with each other, and the first box part 5a and the second box part 5b together define an accommodation space for accommodating the battery cell 6. The second box part 5b can be a hollow structure with one end open, and the first box part 5a is a plate structure, which is overlapped with the open end of the second box part 5b to form the box 5 with the accommodation space; or the first box part 5a and the second box part 5b can both be hollow structures with one side open, and the open side of the first box part 5a is overlapped with the open side of the second box part 5b to form the box 5 with the accommodation space. Of course, the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0123] In order to improve the sealing performance of the first box part 5a and the second box part 5b after being connected, a sealing member, such as a sealing glue, a sealing ring, etc., can be arranged between the first box part 5a and the second box part 5b.

[0124] In some embodiments, the box 5 can be part of the chassis structure of the vehicle. For example, part of the box 5 can be at least part of the floor of the vehicle, or part of the box 5 can be at least part of the cross beam and the longitudinal beam of the vehicle.

[0125] In some embodiments, the battery 2 can be an energy storage device. The energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0126] FIG. 3 is a schematic view of part of the structure of the battery according to some embodiments of the present application.

[0127] Referring to FIG. 3, in some embodiments, the battery 2 includes a plurality of battery cells 6 and a plurality of busbar components 7 electrically connecting the plurality of battery cells 6.

[0128] The plurality of busbar components 7 connect the plurality of battery cells 6 in series, in parallel, or in a mixed connection.

[0129] The plurality of busbar components 7 can have the same structure or different structures.

[0130] The busbar component 7 can have a single-layer structure or a multi-layer structure.

[0131] In some embodiments, the battery cell 6 includes a first electrode terminal 30 and a second electrode terminal 40 with opposite polarities. As an example, the busbar component 7 connects the first electrode terminal 30 of one battery cell 6 and the second electrode terminal 40 of another battery cell 6 to connect the two battery cells 6 in series. Alternatively, the busbar component 7 connects the first electrode terminals 30 of two battery cells 6 to connect the two battery cells 6 in parallel.

[0132] In some embodiments, the busbar component 7 is welded to the first electrode terminal 30.

[0133] In some embodiments, the busbar component 7 has a multi-layer structure. As an example, the busbar component 7 has a multi-layer structure in the thickness direction of the busbar component 7, for example, the busbar component 7 has a double-layer structure or a triple-layer structure by bending.

[0134] Each layer of the busbar component 7 can transmit current. By providing the busbar component 7 with a multi-layer structure, the overcurrent area of the busbar component 7 can be increased, the heat generation of the busbar component 7 when overcurrent occurs can be reduced, the temperature rise of the battery cell 6 can be reduced, and the rapid charging capability of the battery cell 6 can be improved.

[0135] By providing the busbar component 7 with a multi-layer structure, the thickness of each layer of the busbar component 7 can be reduced under the premise that the overcurrent area meets the requirements. The battery cell 6 will swell during the cycle process, thereby stretching the layer of the busbar component 7 connected to the battery cell 6. A layer of the busbar component 7 with a smaller thickness is more likely to deform to adapt to the swelling deformation of the battery cell 6, thereby reducing the risk of the connection between the battery cell 6 and the busbar component 7 being pulled apart and improving the reliability of the battery 2.

[0136] In some embodiments, the battery 2 further includes a heat exchange plate 8 for heat exchange with the outer shell of the battery cell 6.

[0137] The heat exchange plate 8 can exchange heat with the battery cell 6 during the cycle process of the battery cell 6, thereby keeping the battery cell 6 within a suitable temperature range, improving the cycle performance and cycle life of the battery cell 6, and reducing the risk of thermal runaway.

[0138] In some embodiments, the shell has two opposite large faces in the thickness direction of the battery cell 6. The heat exchange plate 8 is arranged on at least one side of the battery cell 6 in the thickness direction of the battery cell 6 and exchanges heat with the large face of the battery cell 6.

[0139] The large face is the largest face in the outer surface of the shell. The large face exchanges heat with the heat exchange plate 8, which improves the heat exchange efficiency, thereby reducing the temperature rise of the battery cell 6 during fast charging, improving the cycle performance and cycle life of the battery cell 6, reducing the risk of thermal runaway, and improving the reliability.

[0140] In some embodiments, the battery cell 6 is provided with the heat exchange plate 8 on both sides, i.e., the two large faces of the battery cell 6 exchange heat with the two heat exchange plates 8, respectively.

[0141] In some embodiments, the battery 2 includes a plurality of heat exchange plates 8 arranged in the thickness direction of the battery cell 6. The battery cell 6 is arranged between adjacent heat exchange plates 8.

[0142] In some embodiments, the battery 2 further includes a heat exchange member 9 for exchanging heat with the electrode terminal.

[0143] The heat exchange member 9 can exchange heat with only the first electrode terminal 30, only the second electrode terminal 40, or both the first electrode terminal 30 and the second electrode terminal 40.

[0144] For example, the first electrode terminal 30 and the second electrode terminal 40 of the same battery cell 6 can exchange heat with the heat exchange member 9, or only the first electrode terminal 30 can exchange heat with the heat exchange member 9.

[0145] For example, for two adjacent battery cells 6, the heat exchange member 9 can exchange heat with the first electrode terminal 30 of both battery cells 6, the first electrode terminal 30 of one battery cell 6 and the second electrode terminal 40 of the other battery cell 6, or the first electrode terminal 30 and the second electrode terminal 40 of both battery cells 6.

[0146] For example, the heat exchange member 9 can directly contact the electrode terminal for heat exchange, or indirectly contact the electrode terminal for heat exchange through other heat-conducting members.

[0147] For example, the heat exchange member 9 can be located inside the box 5 or outside the box 5. Alternatively, the heat exchange member 9 can be located outside the box 5 and exchange heat with the electrode terminal through the box 5.

[0148] In some embodiments, the heat exchange member 9 includes a heat exchange pipe. For example, the heat exchange pipe is a flat pipe.

[0149] In some embodiments, the heat exchange member 9 is internally provided with a flow channel; when the heat exchange medium flows through the flow channel, the heat exchange medium exchanges heat with the electrode terminal through the heat exchange member 9.

[0150] FIG. 4 is a partial cross-sectional view of a battery according to some embodiments of the present application; FIG. 5 is a structural schematic view of a battery according to some embodiments of the present application; FIG. 6 is an exploded schematic view of a battery cell shown in FIG. 5; FIG. 7 is an enlarged schematic view of a portion A of FIG. 4; FIG. 8 is an enlarged schematic view of a portion B of FIG. 4; FIG. 9 is a structural schematic view of an end cover assembly of a battery cell according to some embodiments of the present application; FIG. 10 is a top view of the end cover assembly shown in FIG. 9; and FIG. 11 is a bottom view of the end cover assembly shown in FIG. 9.

[0151] Referring to FIGS. 4-11, in some embodiments, the battery cell 6 includes a housing 20 and an electrode assembly 10, at least a portion of the electrode assembly 10 being accommodated in the housing 20.

[0152] The housing 20 is a hollow structure, and an accommodation space for accommodating the electrode assembly 10 and electrolyte is formed in the housing 20. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a cuboid structure, a cuboid housing can be selected.

[0153] In some embodiments, the housing 20 includes a shell 21 having an opening and an end cover 22 connected to the shell 21 and covering the opening.

[0154] The shell 21 is a component for cooperating with the end cover 22 to form an internal cavity of the battery cell 6, and the internal cavity formed can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0155] The shell 21 and the end cover 22 can be independent components. For example, an opening can be provided on the shell 21, and the end cover 22 is used to cover the opening to form the internal cavity of the battery cell 6.

[0156] The shell 21 can be various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. Specifically, the shape of the shell 21 can be determined according to the specific shape and size of the electrode assembly 10. The shell 21 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of the present application do not make special limitations thereon.

[0157] The shape of the end cover 22 can be adapted to the shape of the shell 21 to fit the shell 21. The material of the end cover 22 can be the same as or different from the material of the shell 21. Optionally, the end cover 22 can be made of a material with certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cover 22 is not easily deformed when subjected to extrusion and collision, and the battery monomer 6 can have higher structural strength and improved reliability.

[0158] The end cover 22 is connected to the shell 21 by welding, bonding, clamping, or other means.

[0159] The shell 21 can be open at one end or both ends. In some examples, the shell 21 can be a structure open on one side, and the end cover 22 is provided as one and covers the shell 21. In other examples, the shell 21 can also be a structure open on both sides, and the end cover 22 is provided as two, and the two end covers 22 cover the two openings of the shell 21, respectively.

[0160] The electrode assembly 10 is a component that undergoes an electrochemical reaction in the battery monomer 6. The shell 21 can contain one or more electrode assemblies 10.

[0161] In some embodiments, the electrode assembly 10 includes a positive electrode sheet and a negative electrode sheet. During charging and discharging of the battery monomer 6, active ions (e.g., lithium ions) are inserted and extracted between the positive electrode sheet and the negative electrode sheet.

[0162] In some embodiments, the electrode assembly 10 further includes a separator film disposed between the positive electrode sheet and the negative electrode sheet, which can prevent the positive and negative electrodes from short-circuiting while allowing the active ions to pass through.

[0163] In some embodiments, the positive electrode sheet can include a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector. For example, the portion of the positive electrode current collector that is not provided with the positive electrode film layer can serve as a positive electrode tab.

[0164] For example, the positive electrode current collector has two opposite surfaces in the thickness direction thereof, and the positive electrode film layer is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0165] In some embodiments, the negative electrode sheet can include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector. For example, the portion of the negative electrode current collector that is not provided with the negative electrode film layer can serve as a negative electrode tab.

[0166] In some embodiments, the electrode assembly 10 includes an electrode body 11, a first tab 12 and a second tab 13, the first tab 12 and the second tab 13 being led out from the electrode body 11. The first tab 12 and the second tab 13 are opposite in polarity, in other words, one of the first tab 12 and the second tab 13 is a positive tab, and the other is a negative tab.

[0167] As an example, the electrode body 11 is constituted by a portion of the positive current collector coated with the positive film layer, a portion of the negative current collector coated with the negative film layer, the positive film layer, the negative film layer, and the separator film. The positive tab and the negative tab can be led out from the same end of the electrode body 11, or can be led out from both ends of the electrode body 11, respectively.

[0168] In some embodiments, the electrode assembly 10 is in a jelly-roll structure. The positive sheet and the negative sheet are wound into the jelly-roll structure.

[0169] In some embodiments, the electrode assembly 10 is in a stack structure.

[0170] As an example, a plurality of positive sheets and a plurality of negative sheets can be provided, respectively, and the plurality of positive sheets and the plurality of negative sheets are alternately stacked.

[0171] As an example, a plurality of positive sheets can be provided, and the negative sheet is folded to form a plurality of folded sections which are stacked, and one positive sheet is sandwiched between adjacent folded sections.

[0172] As an example, both the positive sheet and the negative sheet are folded to form a plurality of folded sections which are stacked.

[0173] As an example, a plurality of separator films can be provided, and each of the plurality of separator films is provided between any adjacent positive sheet or negative sheet.

[0174] As an example, the separator film can be continuously provided, and is provided between any adjacent positive sheet or negative sheet by a folding or winding manner.

[0175] In some embodiments, the battery cell 6 includes a first electrode terminal 30 and a second electrode terminal 40 which are insulated from each other, the first electrode terminal 30 being electrically connected to the first tab 12, and the second electrode terminal 40 being electrically connected to the second tab 13.

[0176] The first electrode terminal 30 and the second electrode terminal 40 are used to be electrically connected to an external circuit to achieve charging or discharging of the battery cell 6.

[0177] As an example, the first electrode terminal 30 can be a separately formed member which is mounted to the housing 20. Alternatively, the first electrode terminal 30 can also be a part of the housing 20.

[0178] As an example, the second electrode terminal 40 can be a separately formed component that is mounted to the housing 20. Alternatively, the second electrode terminal 40 can also be formed as part of the housing 20.

[0179] In some embodiments, both the first electrode terminal 30 and the second electrode terminal 40 are provided on the end cap 22. As an example, the end cap 22, the first electrode terminal 30, and the second electrode terminal 40 can be pre-assembled together, and then assembled with the electrode assembly 10 and the housing 21.

[0180] As an example, the battery cell 6 includes an end cap assembly 50 that includes the end cap 22, the first electrode terminal 30, and the second electrode terminal 40. Optionally, both the first electrode terminal 30 and the second electrode terminal 40 are provided insulated from the end cap 22. Optionally, the first electrode terminal 30 is riveted to the end cap 22, and the second electrode terminal 40 is riveted to the end cap 22.

[0181] In some embodiments, the battery cell 6 further includes a pressure relief mechanism 60. The pressure relief mechanism 60 has an important impact on the reliability of the battery cell 6. For example, when a short circuit, overcharge, or the like occurs, thermal runaway can occur inside the battery cell 6, causing a sudden increase in pressure. In this case, the internal pressure can be released outward by actuating the pressure relief mechanism 60, so as to reduce the risk of explosion or fire of the battery cell 6.

[0182] As an example, the pressure relief mechanism 60 refers to an element or component that is actuated to release internal gas when the internal pressure or temperature of the battery cell 6 reaches a predetermined threshold. The threshold is designed differently according to different design requirements. The threshold can depend on the material of one or more of the positive electrode sheet, the negative electrode sheet, the electrolyte, and the separator in the battery cell 6.

[0183] The pressure relief mechanism 60 can take the form of, for example, a rupture disc, a gas valve, a pressure relief valve, or a safety valve, and can specifically take the form of a pressure-sensitive element or structure, i.e., when the internal pressure of the battery cell 6 reaches a predetermined threshold, the pressure relief mechanism 60 performs an action or a weak zone provided in the pressure relief mechanism 60 breaks, thereby forming an opening or passage for the internal pressure to be released. Alternatively, the pressure relief mechanism 60 can also take the form of a temperature-sensitive element or structure, i.e., when the internal temperature of the battery cell 6 reaches a predetermined threshold, the pressure relief mechanism 60 performs an action, thereby forming an opening or passage for the internal pressure to be released.

[0184] When the battery cell 6 is in thermal runaway, the discharge of the battery cell 6 includes, but is not limited to, electrolyte, dissolved or split positive and negative electrode sheets, fragments of the separator, high-temperature and high-pressure gas generated by the reaction, flames, and the like.

[0185] In some embodiments, the pressure relief mechanism 60 is provided on the housing 20. As an example, the pressure relief mechanism 60 can be provided on the housing 21 or on the end cap 22.

[0186] In some embodiments, the application provides a battery cell 6, which comprises a housing 20, an electrode assembly 10 and a first electrode terminal 30. The housing 20 comprises a first wall portion 20a. The electrode assembly 10 is accommodated in the housing 20, and the electrode assembly 10 comprises a first tab 12. The first electrode terminal 30 is arranged on the first wall portion 20a and electrically connected to the first tab 12, and the first electrode terminal 30 comprises a first terminal portion 31 located outside the first wall portion 20a, and the first terminal portion 31 is used for connecting a first busbar component 7a of a battery 2 and exchanging heat with a heat exchange member 9 of the battery 2.

[0187] The first wall portion 20a can be an end cover 22 or a wall of the shell 21.

[0188] The first tab 12 can be a positive tab or a negative tab. The polarity of the first electrode terminal 30 corresponds to the polarity of the first tab 12.

[0189] The first electrode terminal 30 can be directly connected to the first tab 12 or indirectly connected to the first tab 12 through other conductive structures.

[0190] The first electrode terminal 30 can be one or multiple.

[0191] As an example, in the thickness direction Z of the first wall portion 20a, the first terminal portion 31 is located on the side of the end cover 22 away from the electrode body 11.

[0192] In the cycle process of the battery 2, the current flows through the first busbar component 7a and the first terminal portion 31, causing the first terminal portion 31 and the first busbar component 7a to generate heat. The first terminal portion 31 can exchange heat with the heat exchange member 9, thereby improving the heat dissipation capacity of the battery cell 6, reducing the temperature rise of the battery cell 6, improving the cycle performance and cycle life of the battery cell 6, and reducing the risk of thermal runaway of the battery cell 6 in the rapid charging process. The first electrode terminal 30 is connected to the first tab 12, and the heat of the first tab 12 can also be conducted to the heat exchange member 9 through the first terminal portion 31, thereby reducing the temperature rise of the electrode assembly 10 and improving the cycle performance and cycle life of the battery cell 6. The first terminal portion 31 can simultaneously play the roles of heat dissipation and current transmission, which helps to shorten the heat transfer path between the heat source and the heat exchange member 9 and improve the heat dissipation efficiency.

[0193] In some embodiments, in the thickness direction Z of the first wall portion 20a, the distance between the heat exchange member 9 and the first electrode terminal 30 is smaller than the distance between the heat exchange plate 8 and the first electrode terminal 30.

[0194] In some embodiments, in the thickness direction Z of the first wall portion 20a, the heat exchange plate 8 does not overlap the first electrode terminal 30.

[0195] In some embodiments, the shell 20 comprises a housing 21 having an opening and an end cover 22 connected to the housing 21 and covering the opening. The end cover 22 is the first wall portion 20a.

[0196] Compared with the housing 21, the end cover 22 generally has a larger thickness. By arranging the first electrode terminal 30 on the end cover 22, the connection strength between the first electrode terminal 30 and the end cover 22 can be improved, the stability of the first electrode terminal 30 can be improved, and the risk of the first electrode terminal 30 deviating can be reduced.

[0197] In the production process of the battery cell 6, the first electrode terminal 30 and the end cover 22 can be assembled in advance, and then assembled with the housing 21, the electrode assembly 10 and other components. The first electrode terminal 30 and the end cover 22 are integrally provided, which can simplify the assembly process.

[0198] In some embodiments, the first wall portion 20a is provided with an electrolyte injection hole 223. In the production process of the battery cell 6, electrolyte can be injected into the shell 20 through the electrolyte injection hole 223.

[0199] After the process related to the electrolyte injection hole 223 is completed, the sealing sheet 70 can be installed on the first wall portion 20a to seal the electrolyte injection hole 223.

[0200] In some embodiments, the first electrode terminal 30 is directly connected to the first tab 12. Optionally, the first electrode terminal 30 is welded to the first tab 12.

[0201] Directly connecting the first electrode terminal 30 to the first tab 12 can not only save the traditional adapter sheet, but also shorten the conductive path, reduce the resistance, and reduce the heat generation. In addition, directly connecting the first electrode terminal 30 to the first tab 12 can also shorten the heat transfer path between the first tab 12 and the heat exchange member 9, improve the heat dissipation capacity, and reduce the temperature rise of the first tab 12.

[0202] In some embodiments, the electrode assembly 10 further comprises a second tab 13, and the first tab 12 and the second tab 13 are opposite in polarity. The battery cell 6 further comprises a second electrode terminal 40 arranged on the shell 20, and the second electrode terminal 40 is electrically connected to the second tab 13.

[0203] The first electrode terminal 30 and the second electrode terminal 40 can be arranged on the same wall portion of the shell 20, or can be arranged on two wall portions of the shell 20, respectively. Exemplarily, the first electrode terminal 30 and the second electrode terminal 40 are both arranged on the first wall portion 20a.

[0204] The second electrode terminal 40 can be directly connected to the second tab 13, or can be indirectly connected to the second tab 13 through other conductive structures.

[0205] The second electrode terminal 40 can exchange heat with the heat exchange member 9 or can not exchange heat with the heat exchange member 9.

[0206] In some embodiments, the second electrode terminal 40 is directly connected to the second tab 13. Alternatively, the second electrode terminal 40 is welded to the second tab 13.

[0207] Directly connecting the second electrode terminal 40 to the second tab 13 can save a traditional adapter piece and shorten the conductive path, reduce the resistance, and reduce the heat generation.

[0208] In some embodiments, the second electrode terminal 40 can be used to connect the second busbar component 7b of the battery.

[0209] The first electrode terminal 30 and the second electrode terminal 40 of the battery cell 6 are generally connected to two busbar components 7 respectively. The busbar component 7 connected to the first electrode terminal 30 is the first busbar component 7a, and the busbar component 7 connected to the second electrode terminal 40 is the second busbar component 7b.

[0210] For example, two adjacent battery cells 6 are connected in series by a busbar component 7, which is connected to the first electrode terminal 30 of one battery cell 6 and the second electrode terminal 40 of the other battery cell 6. Correspondingly, the busbar component 7 is the first busbar component 7a for one battery cell 6 and the second busbar component 7b for the other battery cell 6.

[0211] In some embodiments, the housing 20 includes a second wall portion 20b, and the battery cell 6 includes a pressure relief mechanism 60 arranged on the second wall portion 20b.

[0212] The second wall portion 20b can be a wall portion arranged opposite to the first wall portion 20a or a wall portion directly connected to the first wall portion 20a.

[0213] Arranging the pressure relief mechanism 60 on the second wall portion 20b can reserve more space on the first wall portion 20a for mounting the first electrode terminal 30, so that the first terminal portion 31 can have a larger exposed area, improve the heat dissipation capacity of the first terminal portion 31, reduce the temperature rise of the first terminal portion 31, and improve the cycle performance and cycle life of the battery cell 6.

[0214] In some embodiments, along the thickness direction Z of the first wall portion 20a, the first wall portion 20a and the second wall portion 20b are respectively located on two sides of the electrode body 11.

[0215] For example, the second wall portion 20b is the bottom wall of the shell 21.

[0216] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the second electrode terminal 40 is a negative electrode terminal. Alternatively, the first electrode terminal 30 is a negative electrode terminal, and the second electrode terminal 40 is a positive electrode terminal.

[0217] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the material of the first electrode terminal 30 includes aluminum.

[0218] For example, the material of the first electrode terminal 30 is aluminum or an aluminum alloy.

[0219] Aluminum has good thermal conductivity and electrical conductivity. By using aluminum for the first electrode terminal 30, the heat generation of the first electrode terminal 30 can be reduced, and the heat exchange efficiency between the first electrode terminal 30 and the heat exchange member 9 can be improved.

[0220] In some embodiments, the first tab 12 is a positive tab, and the material of the first tab 12 is aluminum; the second tab 13 is a negative tab, and the material of the second tab 13 is copper; the first electrode terminal 30 is a positive electrode terminal, and the material of the first electrode terminal 30 includes aluminum. Compared with copper, aluminum has poorer thermal conductivity. By exchanging heat between the heat exchange member 9 and the first electrode terminal 30, the efficiency of heat dissipation of the first tab 12 to the outside can be improved, and the temperature difference between the first tab 12 and the second tab 13 can be reduced.

[0221] In some embodiments, the projection of the first terminal portion 31 along the thickness direction Z is generally rectangular.

[0222] In some embodiments, the first terminal portion 31 includes a first portion 311 and a second portion 312, the first portion 311 is configured to be connected to the first bus member 7a, and the second portion 312 is configured to exchange heat with the heat exchange member 9.

[0223] The thickness of the first portion 311 and the thickness of the second portion 312 can be the same or different.

[0224] In the first direction X, the size of the first portion 311 and the size of the second portion 312 can be the same or different; in the second direction Y, the size of the first portion 311 and the size of the second portion 312 can be the same or different.

[0225] For example, the first direction X, the second direction Y, and the thickness direction Z of the first wall portion 20a are perpendicular to each other.

[0226] For example, the first direction X is parallel to the length direction of the first wall portion 20a, and the second direction Y is parallel to the width direction of the first wall portion 20a.

[0227] The first portion 311 and the second portion 312 can be connected or separated.

[0228] In the embodiments of the present application, the first bus member 7a and the heat exchange member 9 act on different parts of the first terminal part 31 respectively, so that the risk of interference between the first bus member 7a and the heat exchange member 9 can be reduced.

[0229] In some embodiments, the first part 311 is configured to at least partially overlap and connect with the first bus member 7a in the thickness direction Z of the first wall part 20a, and the second part 312 is configured to at least partially overlap with the heat exchange member 9 in the thickness direction Z.

[0230] The first part 311 is arranged with the first bus member 7a in the thickness direction Z, which can increase the connection strength and the flow area between the first part 311 and the first bus member 7a, and reduce heat generation. The second part 312 is arranged with the heat exchange member 9 in the thickness direction Z, which can increase the heat exchange area of the second part 312 and the heat exchange member 9, and improve the heat exchange efficiency. The first bus member 7a and the heat exchange member 9 can share space in the thickness direction Z, thereby improving the space utilization in the thickness direction Z and improving the energy density of the battery 2.

[0231] In some embodiments, the first bus member 7a is arranged on the side of the first part 311 away from the first wall part 20a and connected to the first part 311.

[0232] In some embodiments, the heat exchange member 9 is arranged on the side of the second part 312 away from the first wall part 20a.

[0233] In some embodiments, the thickness t1 of the first part 311 is greater than the thickness t2 of the second part 312.

[0234] Exemplarily, in the thickness direction Z of the first wall part 20a, the surface of the first part 311 away from the first wall part 20a can be flush with the surface of the second part 312 away from the first wall part 20a, or can not be flush.

[0235] The first part 311 has a greater thickness than the second part 312, and the first part 311 is less likely to be melted through when welded with the first bus member 7a, thereby improving the reliability of the battery monomer 6. The second part 312 does not need to be welded with the first bus member 7a, and can have a smaller thickness, thereby reducing the volume and weight of the first electrode terminal 30 and improving the energy density of the battery monomer 6.

[0236] In some embodiments, the thickness of the first part 311 is greater than or equal to 3 mm.

[0237] In some embodiments, the ratio of the thickness of the first part 311 to the thickness of the second part 312 is 1.2-3. Optionally, t1 / t2 is 1.2, 1.5, 2, 2.5 or 3.

[0238] In some embodiments, the first portion 311 extends beyond the second portion 312 in a direction away from the first wall portion 20a.

[0239] In the thickness direction Z of the first wall portion 20a, the surface of the second portion 312 away from the first wall portion 20a is closer to the first wall portion 20a than the surface of the second portion 312 away from the first wall portion 20a, thereby reserving more space on the side of the second portion 312 away from the first wall portion 20a to facilitate the arrangement of the heat exchange member 9 and improve space utilization.

[0240] In some embodiments, the first terminal portion 31 has a first recess 313 on the side away from the first wall portion 20a, and the second portion 312 is a bottom wall of the first recess 313.

[0241] By providing the first recess 313, space can be provided for the heat exchange member 9, improving space utilization in the thickness direction Z of the first wall portion 20a.

[0242] In some embodiments, the first busbar component 7a is laser welded with the first portion 311.

[0243] In some embodiments, the first recess 313 is located on one side of the first portion 311 in the first direction X. The end of the first recess 313 away from the first portion 311 in the first direction X can extend to the edge of the first terminal portion 31; alternatively, the end of the first recess 313 away from the first portion 311 in the first direction X can also not extend to the edge of the first terminal portion 31, i.e. the first terminal portion 31 can further include a third portion (not shown), the thickness of the third portion being greater than the thickness of the second portion 312, the second portion 312 being connected between the first portion 311 and the third portion, and the first recess 313 being located between the first portion 311 and the third portion in the first direction X.

[0244] In some embodiments, in the second direction Y, the first recess 313 extends through the first terminal portion 31.

[0245] In some embodiments, in the thickness direction Z of the first wall portion 20a, the depth h of the first recess 313 is 0.1mm-2mm.

[0246] As an example, h is 0.1mm, 0.2mm, 0.3mm, 0.5mm, 0.6mm, 0.8mm, 1.0mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.8mm or 2.0mm.

[0247] The depth of the first recess 313 is greater than or equal to 0.1 mm, which provides more space for other components (e.g., the heat exchange member 9) and improves space utilization. The depth of the first recess 313 is less than or equal to 2 mm, which reduces the loss of thermal conductivity of the second portion 312 due to thinning and balances the heat exchange efficiency of the second portion 312 and the heat exchange member 9 to some extent.

[0248] In some embodiments, the area of the second portion 312 is greater than the area of the first portion 311 as viewed in the thickness direction Z, which allows the heat exchange area between the first terminal portion 31 and the heat exchange member 9 to be larger.

[0249] In some embodiments, the first portion 311 and the second portion 312 are arranged along a first direction X that is perpendicular to the thickness direction Z of the first wall portion 20a. In the first direction X, the size L22 of the second portion 312 is greater than the size L21 of the first portion 311.

[0250] The second portion 312 has a size greater than the first portion 311 in the first direction X, which increases the heat exchange area between the second portion 312 and the heat exchange member 9, improves the heat exchange efficiency, reduces the temperature rise inside the battery cell 6, and improves the cycle performance of the battery cell 6.

[0251] In some embodiments, the surface of the first terminal portion 31 away from the first wall portion 20a is configured to be connected to the heat exchange member 9.

[0252] As an example, the surface of the first terminal portion 31 away from the first wall portion 20a can be a flat surface or a stepped surface.

[0253] The surface of the first terminal portion 31 away from the first wall portion 20a can be in contact with the heat exchange member 9 or indirectly connected to the heat exchange member 9 through other components. For example, the surface of the first terminal portion 31 away from the first wall portion 20a can be thermally bonded to the heat exchange member 9.

[0254] In some embodiments, the surface of the first terminal portion 31 away from the first wall portion 20a includes a first region 31a configured to be connected to the first bus member 7a and a second region 31b configured to be arranged opposite the heat exchange member 9 in the thickness direction Z.

[0255] As an example, the first region 31a is arranged in abutment with the first bus member 7a.

[0256] As an example, in the thickness direction Z, the projection of the second region 31b is located within the projection of the heat exchange member 9.

[0257] The first region 31a and the second region 31b can be flush or offset in the thickness direction Z of the first wall portion 20a.

[0258] As an example, in FIG. 10, the first region 31a and the second region 31b are shown by diagonal lines.

[0259] The first region 31a and the second region 31b can be directly connected or spaced apart.

[0260] The first busbar component 7a and the heat exchange member 9 respectively act on the first region 31a and the second region 31b, which can reduce the risk of interference between the first busbar component 7a and the heat exchange member 9, and reduce the superposition of the first busbar component 7a and the heat exchange member 9 in the thickness direction Z, and improve the space utilization.

[0261] In some embodiments, the first region 31a is spaced apart from the second region 31b to reduce the risk of interference between the first busbar component 7a and the heat exchange member 9 due to assembly errors.

[0262] In some embodiments, the area of the second region 31b is greater than the area of the first region 31a. The larger area of the second region 31b can improve the heat exchange efficiency between the heat exchange member 9 and the first terminal portion 31, reduce the temperature rise of the first terminal portion 31, and improve the cycle performance and reliability performance of the battery monomer 6.

[0263] In some embodiments, the ratio of the area of the first region 31a to the projected area of the first terminal portion 31 in the thickness direction Z is greater than or equal to 1.5%, so that the first terminal portion 31 and the first busbar component 7a have a larger connection area and a higher connection strength, improve the flow capacity between the first terminal portion 31 and the first busbar component 7a, reduce heat generation, and reduce temperature rise.

[0264] As an example, the ratio of the area of the first region 31a to the projected area of the first terminal portion 31 in the thickness direction Z is 1.5%, 2%, 3%, 5%, 8%, 10%, 15%, 20%, 25%, or 30%.

[0265] In some embodiments, the area of the first region 31a is greater than or equal to 20mm 2 . Alternatively, the area of the first region 31a is 20mm 2 , 25mm 2 , 30mm 2 , 35mm 2 , 40mm 2 , 45mm 2 , 50mm 2 , 60mm 2 , 80mm 2 , or 100mm 2The first terminal portion 31 has a large connection area and high connection strength with the first bus member 7a, improves the current carrying capacity between the first terminal portion 31 and the first bus member 7a, reduces heat generation, and lowers temperature rise.

[0266] In some embodiments, the ratio of the area of the second region 31b to the projected area of the first terminal portion 31 along the thickness direction Z is greater than or equal to 10%, so that the first terminal portion 31 has a large heat exchange area with the heat exchange member 9, improves the heat exchange efficiency between the first terminal portion 31 and the heat exchange member 9, reduces the temperature rise of the first terminal portion 31 and the temperature rise of the electrode assembly 10, and improves the cycle performance of the battery cell 6.

[0267] For example, the ratio of the area of the second region 31b to the projected area of the first terminal portion 31 along the thickness direction Z is 10%, 12%, 14%, 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0268] In some embodiments, the ratio of the area of the first region 31a to the projected area of the first terminal portion 31 along the thickness direction Z is less than or equal to 70%, and optionally less than or equal to 40%.

[0269] In some embodiments, the first portion 311 includes the first region 31a, and the second portion 312 includes the second region 31b.

[0270] In some embodiments, the first wall portion 20a is provided with a first electrode lead-out hole 221.

[0271] For example, the first electrode lead-out hole 221 penetrates the first wall portion 20a along the thickness direction Z of the first wall portion 20a.

[0272] The first electrode lead-out hole 221 can be one or multiple.

[0273] The first electrode lead-out hole 221 can be a circular hole, a rectangular hole, an oval hole, a racetrack-shaped hole, or a hole of other shapes.

[0274] The first electrode lead-out hole 221 is provided to facilitate electrical connection between the first terminal portion 31 and the first tab 12.

[0275] In some embodiments, the first electrode terminal 30 further includes a second terminal portion 32 and a third terminal portion 33, the second terminal portion 32 is located inside the first wall portion 20a and electrically connected to the first tab 12, at least part of the third terminal portion 33 is accommodated in the first electrode lead-out hole 221, and the third terminal portion 33 connects the second terminal portion 32 and the first terminal portion 31. In the thickness direction Z, a portion of the first wall portion 20a is located between the first terminal portion 31 and the second terminal portion 32.

[0276] The third terminal portion 33 and the first terminal portion 31 can be integrally formed. Alternatively, the third terminal portion 33 and the first terminal portion 31 can be separately formed and fixedly connected by welding, clamping, bonding or other means.

[0277] The third terminal portion 33 and the second terminal portion 32 can be integrally formed. Alternatively, the third terminal portion 33 and the second terminal portion 32 can be separately formed and fixedly connected by welding, clamping, bonding or other means.

[0278] The third terminal portion 33 can be one or multiple.

[0279] The third terminal portion 33 and the first terminal portion 31 can be made of the same material or different materials.

[0280] The second terminal portion 32 can be directly connected to the first tab 12, for example, the second terminal portion 32 is welded to the first tab 12. Alternatively, the second terminal portion 32 can be connected to the first tab 12 through other conductive structures (for example, a jumper).

[0281] The first wall portion 20a can limit the third terminal portion 33 in the radial direction of the first electrode lead-out hole 221. The first terminal portion 31 and the second terminal portion 32 can clamp the first wall portion 20a from both sides, thereby achieving fixation in the thickness direction Z.

[0282] In some embodiments, the second terminal portion 32 and the third terminal portion 33 are integrally formed, which can improve the connection strength between the second terminal portion 32 and the third terminal portion 33, reduce the resistance, and improve the overcurrent capacity.

[0283] Exemplarily, the third terminal portion 33 protrudes from the surface of the second terminal portion 32 facing the first wall portion 20a.

[0284] In some embodiments, the first terminal portion 31 is provided with a first through hole 314 penetrating the first terminal portion 31 in the thickness direction Z of the first wall portion 20a. A part of the third terminal portion 33 is accommodated in the first through hole 314 and connected to the first terminal portion 31.

[0285] Exemplarily, the first through hole 314 can be a constant-diameter hole or a variable-diameter hole. For example, the first through hole 314 can be a stepped hole.

[0286] In the thickness direction Z, the end of the third terminal portion 33 away from the second terminal portion 32 can or can not protrude out of the first through hole 314.

[0287] In the thickness direction Z, the end of the third terminal portion 33 away from the second terminal portion 32 can or can not overlap with the first busbar component 7a.

[0288] In the thickness direction Z, one end of the third terminal portion 33 away from the second terminal portion 32 can or can not overlap with the heat exchange member 9.

[0289] In assembly, the third terminal portion 33 can be first passed through the first electrode lead-out hole 221 and the first through hole 314, and then the third terminal portion 33 is connected with the first terminal portion 31. By setting the first through hole 314, the assembly process can be simplified.

[0290] In some embodiments, the first terminal portion 31 and the second terminal portion 32 are both flat plates. The third terminal portion 33 is a column.

[0291] In some embodiments, the third terminal portion 33 is riveted to the first terminal portion 31.

[0292] In some embodiments, in the thickness direction Z, one end of the third terminal portion 33 away from the second terminal portion 32 does not exceed the first through hole 314, so as to reduce the risk of the third terminal portion 33 interfering with the connection of the first terminal portion 31 with the first busbar member 7a, or the risk of the third terminal portion 33 interfering with the connection of the first terminal portion 31 with the heat exchange member 9.

[0293] In some embodiments, the first electrode terminal 30 includes a plurality of third terminal portions 33 arranged at intervals. By setting a plurality of third terminal portions 33, the current carrying capacity can be improved, the heat generation can be reduced, and the structural strength of the first electrode terminal 30 can be improved, thereby improving the stability of the connection of the first electrode terminal 30 with the first wall portion 20a.

[0294] In some embodiments, the first electrode lead-out hole 221 is a plurality of first electrode lead-out holes 221, and the plurality of first electrode lead-out holes 221 are arranged one-to-one with the plurality of third terminal portions 33.

[0295] In some embodiments, the first portion 311 is connected to the second terminal portion 32 through at least one third terminal portion 33, and the second portion 312 is connected to the second terminal portion 32 through at least one third terminal portion 33.

[0296] Connecting the first portion 311 with the third terminal portion 33 can improve the stability of the first portion 311. When the battery monomer 6 is subjected to external impact, the third terminal portion 33 can limit the deformation of the first portion 311, thereby reducing the risk of failure of the connection of the first portion 311 with the first busbar member 7a.

[0297] Connecting the second portion 312 with the third terminal portion 33 can limit the deformation of the second portion 312 when the battery monomer 6 is subjected to external impact, thereby reducing the stability of the heat exchange interface between the second portion 312 and the heat exchange member 9.

[0298] In some embodiments, the first terminal portion 31 comprises a first edge 31c and a second edge 31d oppositely arranged along a first direction X, the first direction X being parallel to a length direction of the first wall portion 20a. The first terminal portion 31 is provided with two first through holes 314 arranged at intervals along the first direction X, and the two third terminal portions 33 are respectively arranged through the two first through holes 314 and connected to the first terminal portion 31. In the first direction X, a distance between the first edge 31c and an axis of the first through hole 314 close to the first edge 31c is D1, a distance between the second edge 31d and an axis of the first through hole 314 close to the second edge 31d is D2, and a distance between the axes of the two first through holes 314 is D3. D1 / D2 is 0.9-1.1, and (D1+D2) / D3 is 0.9-1.1.

[0299] For example, D1 / D2 is 0.9, 0.95, 1, 1.05 or 1.1.

[0300] For example, (D1+D2) / D3 is 0.9, 0.95, 1, 1.05 or 1.1.

[0301] From the thickness direction Z, the two third terminal portions 33 are approximately symmetrically arranged, which can improve the stability of the first terminal portion 31 and the structural strength of the first electrode terminal 30.

[0302] In some embodiments, D1=D2, and optionally, D3=2×D1.

[0303] In some embodiments, a cross section of the third terminal portion 33 perpendicular to the thickness direction Z of the first wall portion 20a is circular, elliptical or track-shaped.

[0304] In some examples, the cross section of the third terminal portion 33 is circular, and correspondingly, the first electrode lead-out hole 221 is a circular hole. The circular third terminal portion 33 is easy to process and form; the first electrode lead-out hole 221 can be sealed by a circular sealing ring, the deformation amount of the circular sealing ring is uniform, and the sealing effect is good.

[0305] In other examples, the cross section of the third terminal portion 33 is track-shaped, and correspondingly, the first electrode lead-out hole 221 is track-shaped. The track-shaped third terminal portion 33 can have a larger cross-sectional area than the circular third terminal portion 33, so as to improve the flow capacity of the third terminal portion 33. Of course, compared with the track-shaped third terminal portion 33, the circular third terminal portion 33 is easier to process.

[0306] In still other examples, the cross section of the third terminal portion 33 is elliptical.

[0307] In some embodiments, the first tab 12 is welded to the second terminal portion 32 and forms a first welding mark 80a.

[0308] Directly welding the first tab 12 and the second terminal portion 32 can shorten the conductive path between the first tab 12 and the second terminal portion 32, reduce the resistance, and reduce the heat generation of the first tab 12 and the second terminal portion 32.

[0309] In some embodiments, the first tab 12 is connected to the second terminal portion 32 by laser welding or ultrasonic welding.

[0310] In some embodiments, the first welding mark 80a is configured to at least partially overlap the heat exchange member 9 in the thickness direction Z of the first wall portion 20a.

[0311] The first welding mark 80a generates heat when current passes through the first welding mark 80a. The embodiments of the present application can reduce the distance between the first welding mark 80a and the heat exchange member 9, improve the heat dissipation efficiency of the first welding mark 80a, and reduce the temperature rise of the first welding mark 80a.

[0312] In some embodiments, the projected area of the first terminal portion 31 is greater than the projected area of the second terminal portion 32 in the thickness direction Z of the first wall portion 20a.

[0313] Compared with the second terminal portion 32, the first terminal portion 31 can have a larger area, which can improve the heat dissipation efficiency of the first terminal portion 31; under the premise that the overcurrent area meets the requirements, the second terminal portion 32 can have an area smaller than that of the first terminal portion 31, thereby saving the internal space of the shell 20 and improving the energy density of the battery monomer 6.

[0314] In some embodiments, the projected area S1 of the first terminal portion 31 is 0.2-0.5 times the projected area S3 of the first wall portion 20a in the thickness direction Z of the first wall portion 20a.

[0315] Optionally, S1 / S3 is 0.2, 0.3, 0.4, or 0.5.

[0316] The ratio of the projected area of the first terminal portion 31 to the projected area of the first wall portion 20a is greater than or equal to 0.2, and the first terminal portion 31 can reserve a larger area for heat exchange with the heat exchange member 9, thereby improving the heat exchange efficiency and improving the cycle performance and reliability of the battery monomer 6. The ratio of the projected area of the first terminal portion 31 to the projected area of the first wall portion 20a is less than or equal to 0.5, which can reserve installation space for other components of the battery monomer 6.

[0317] In some embodiments, the first wall portion 20a and the first terminal portion 31 are both rectangular as viewed in the thickness direction Z, the length of the first wall portion 20a is L1, the width of the first wall portion 20a is W1, the length of the first terminal portion 31 is L2, and the width of the first terminal portion 31 is W2. (L2×W2) / (L1×W1) is 0.2-0.5.

[0318] It is explained that the rectangle does not require to be an absolute rectangle, for example, the four corners of the rectangle can be set as rounded corners.

[0319] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the second terminal portion 32 is 0.2-0.5 times the projected area of the first wall portion 20a.

[0320] The ratio of the projected area of the second terminal portion 32 to the projected area of the first wall portion 20a is greater than or equal to 0.2, and the second terminal portion 32 and the first tab 12 can have a larger connection area and a larger flow area, thereby reducing the resistance, reducing the heat generation of the second terminal portion 32 and the heat generation of the first tab 12, and reducing the temperature rise of the battery monomer 6. The ratio of the projected area of the second terminal portion 32 to the projected area of the first wall portion 20a is less than or equal to 0.5, which can reserve installation space for other components inside the shell 20, reduce the risk of interference and short circuit between the second terminal portion 32 and other components, and improve the reliability of the battery monomer 6.

[0321] In some embodiments, the second electrode terminal 40 includes a fourth terminal portion 41 located on the outside of the shell 20. Exemplarily, the fourth terminal portion 41 can be used to connect with the second bus component 7b.

[0322] The second electrode terminal 40 can be arranged on the first wall portion 20a, the second wall portion 20b, or other wall portions of the shell 20.

[0323] Exemplarily, the fourth terminal portion 41 can be arranged close to the heat exchange member 9 to exchange heat with the heat exchange member 9; alternatively, the fourth terminal portion 41 can be arranged away from the heat exchange member 9 to reduce the heat exchange with the heat exchange member 9.

[0324] Exemplarily, the area of the fourth terminal portion 41 can be greater than, less than, or equal to the area of the first terminal portion 31.

[0325] In some embodiments, the projected area of the first terminal portion 31 along the thickness direction thereof is greater than the projected area of the fourth terminal portion 41 along the thickness direction thereof.

[0326] The thickness direction of the first terminal portion 31 can be parallel to the thickness direction Z of the first wall portion 20a.

[0327] The thickness direction of the fourth terminal portion 41 is related to the position of the second electrode terminal 40. Exemplarily, the fourth terminal portion 41 is arranged on the first wall portion 20a, and the thickness direction of the fourth terminal portion 41 can be parallel to the thickness direction Z of the first wall portion 20a. Exemplarily, the fourth terminal portion 41 is arranged on the second wall portion 20b, and the thickness direction of the fourth terminal portion 41 can be parallel to the thickness direction of the second wall portion 20b.

[0328] The first terminal portion 31 can be arranged to be larger to increase the heat exchange area and improve the heat exchange efficiency. The fourth terminal portion 41 can be arranged to be smaller to save space and improve the energy density of the battery cell 6.

[0329] In some embodiments, the projected area of the first terminal portion 31 along the thickness direction thereof is 1.2-5 times the projected area of the fourth terminal portion 41 along the thickness direction thereof. Optionally, the projected area of the first terminal portion 31 along the thickness direction thereof is 2-3 times the projected area of the fourth terminal portion 41 along the thickness direction thereof.

[0330] For example, the projected area of the first terminal portion 31 along the thickness direction thereof is equal to S1, and the projected area of the fourth terminal portion 41 along the thickness direction thereof is equal to S2. Optionally, S1 / S2 is 1.2, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5.

[0331] S1 / S2 is limited to be greater than or equal to 1.2 to increase the heat exchange area between the first terminal portion 31 and the heat exchange member 9 and improve the heat exchange efficiency. S1 / S2 is limited to be less than or equal to 5 to balance the flow capacity of the first terminal portion 31 and the fourth terminal portion 41 to some extent.

[0332] The embodiments of the present application can balance the heat exchange area of the first terminal portion 31, the flow capacity of the first terminal portion 31, and the flow capacity of the fourth terminal portion 41 to some extent, and improve the cycle performance of the battery cell 6.

[0333] In some embodiments, the fourth terminal portion 41 is substantially rectangular, the length of the fourth terminal portion 41 is L3, and the width of the fourth terminal portion 41 is W3.

[0334] Optionally, (L2×W2) / (L3×W3) is 1.2-5, and is optionally 2-3.

[0335] In some embodiments, the second electrode terminal 40 is arranged on the first wall portion 20a, and the second electrode terminal 40 includes the fourth terminal portion 41 arranged outside the first wall portion 20a. In the thickness direction Z of the first wall portion 20a, the projected area of the first terminal portion 31 is S1, the projected area of the fourth terminal portion 41 is S2, and the projected area of the first wall portion 20a is S3. S1, S2, and S3 satisfy: 0.2≤(S1+S2) / S3≤0.8.

[0336] Setting (S1+S2) / S3 to be greater than or equal to 0.2 can make the first terminal portion 31 and the fourth terminal portion 41 have a larger area, thereby improving the heat dissipation capacity and overcurrent capacity of the first electrode terminal 30 and the heat dissipation capacity and overcurrent capacity of the second electrode terminal 40, and improving the cycle performance of the battery monomer 6. Setting (S1+S2) / S3 to be less than or equal to 0.8 can reserve installation space for other components and maintain the distance between the first terminal portion 31 and the second terminal portion 32, thereby reducing the risk of short circuit.

[0337] Optionally, (S1+S2) / S3 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8.

[0338] Optionally, 0.3≤(S1+S2) / S3≤0.5.

[0339] Optionally, S1 / S2 is 1.5-3, and is optionally 2-3.

[0340] In some embodiments, the second electrode terminal 40 is disposed on the first wall portion 20a, and the second electrode terminal 40 includes a fourth terminal portion 41 located outside the first wall portion 20a. In the thickness direction Z of the first wall portion 20a, the fourth terminal portion 41 does not overlap the heat exchange member 9.

[0341] In the case where the heat exchange efficiency of the heat exchange member 9 and the first terminal portion 31 meets the demand, the heat exchange member 9 can not exchange heat with the fourth terminal portion 41, which can reduce the volume of the heat exchange member 9, reduce the layout difficulty of the heat exchange member 9, and improve the energy density of the battery 2.

[0342] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the second portion 312 is greater than the projected area of the fourth terminal portion 41. Optionally, the projected area of the second portion 312 is 1.5-3 times the projected area of the fourth terminal portion 41.

[0343] In some embodiments, the housing 20 is provided with a second electrode lead-out hole 222.

[0344] The second electrode lead-out hole 222 can be disposed on the first wall portion 20a, the second wall portion 20b, or other wall portions of the housing 20. As an example, the second electrode lead-out hole 222 is disposed on the first wall portion 20a and penetrates the first wall portion 20a in the thickness direction Z of the first wall portion 20a.

[0345] The second electrode lead-out hole 222 can be one or multiple.

[0346] The second electrode lead-out hole 222 can be a circular hole, a rectangular hole, an oval hole, a racetrack-shaped hole, or a hole of other shapes.

[0347] The second electrode lead-out hole 222 is provided to facilitate electrical connection between the fourth terminal portion 41 and the second tab 13.

[0348] In some embodiments, the second electrode terminal 40 further comprises a fourth terminal portion 41, a fifth terminal portion 42 and a sixth terminal portion 43, the fourth terminal portion 41 is located outside the housing 20, the fifth terminal portion 42 is located inside the housing 20 and is electrically connected to the second tab 13, at least part of the sixth terminal portion 43 is accommodated in the second electrode lead-out hole 222, and the sixth terminal portion 43 connects the fifth terminal portion 42 and the fourth terminal portion 41.

[0349] The sixth terminal portion 43 and the fourth terminal portion 41 can be an integrally formed structure. Alternatively, the sixth terminal portion 43 and the fourth terminal portion 41 can also be independently formed and fixedly connected by welding, clamping, bonding or other means.

[0350] The sixth terminal portion 43 and the fifth terminal portion 42 can be an integrally formed structure. Alternatively, the sixth terminal portion 43 and the fifth terminal portion 42 can also be independently formed and fixedly connected by welding, clamping, bonding or other means.

[0351] The sixth terminal portion 43 can be one or multiple.

[0352] The sixth terminal portion 43 and the fourth terminal portion 41 can be made of the same material or different materials.

[0353] The fifth terminal portion 42 can be directly connected to the second tab 13, for example, the fifth terminal portion 42 is welded to the second tab 13 and forms a second welding mark 80b. Alternatively, the fifth terminal portion 42 can also be connected to the second tab 13 through other conductive structures (such as a jumper).

[0354] In some embodiments, the sixth terminal portion 43 and the fifth terminal portion 42 are an integrally formed structure, which can improve the connection strength between the sixth terminal portion 43 and the fifth terminal portion 42, reduce the resistance, and improve the overcurrent capacity.

[0355] In some embodiments, the fourth terminal portion 41 is provided with a second through hole 414 that penetrates the fourth terminal portion 41. Part of the sixth terminal portion 43 is accommodated in the second through hole 414 and connected to the fourth terminal portion 41.

[0356] Exemplarily, the second through hole 414 can be a constant-diameter hole or a variable-diameter hole. For example, the second through hole 414 can be a stepped hole.

[0357] The end of the sixth terminal portion 43 away from the second terminal portion 32 can or can not extend beyond the second through hole 414.

[0358] In the assembly, the sixth terminal portion 43 can be first inserted through the second electrode lead-out hole 222 and the second through hole 414, and then the sixth terminal portion 43 is connected with the fourth terminal portion 41. By providing the second through hole 414, the assembly process can be simplified.

[0359] In some embodiments, the fourth terminal portion 41 and the fifth terminal portion 42 are both flat plates. The sixth terminal portion 43 is a column.

[0360] In some embodiments, the sixth terminal portion 43 is riveted to the fourth terminal portion 41.

[0361] In some embodiments, in the axial direction of the second electrode lead-out hole 222, the end of the sixth terminal portion 43 away from the fifth terminal portion 42 does not exceed the second through hole 414, so as to reduce the risk of interference of the connection between the fourth terminal portion 41 and the second bus member 7b by the sixth terminal portion 43.

[0362] Optionally, the second electrode terminal 40 is arranged on the first wall portion 20a, and the axial direction of the second electrode lead-out hole 222 is parallel to the thickness direction Z of the first wall portion 20a.

[0363] In some embodiments, the second electrode terminal 40 includes one sixth terminal portion 43. The fourth terminal portion 41 and the fifth terminal portion 42 can have a smaller area, and therefore, the use of one sixth terminal portion 43 can stably connect the fourth terminal portion 41 and the fifth terminal portion 42, thereby simplifying the structure of the second electrode terminal 40 and reducing the volume of the second electrode terminal 40.

[0364] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the second electrode terminal 40 is a negative electrode terminal.

[0365] The first terminal portion 31, the second terminal portion 32, and the third terminal portion 33 include the same base metal. The base metal is the metal with the highest content in the composition. For example, the base metal of the first terminal portion 31, the second terminal portion 32, and the third terminal portion 33 is aluminum, for example, the material of the first terminal portion 31 is aluminum or aluminum alloy, the material of the second terminal portion 32 is aluminum or aluminum alloy, and the material of the third terminal portion 33 is aluminum or aluminum alloy.

[0366] The base metal of the second terminal portion 32 is the same as the base metal of the first tab 12.

[0367] The fifth terminal portion 42 and the sixth terminal portion 43 include the same base metal. For example, the base metal of the fifth terminal portion 42 and the sixth terminal portion 43 is copper. For example, the material of the fifth terminal portion 42 is copper or copper alloy, and the material of the sixth terminal portion 43 is copper or copper alloy.

[0368] The base metal of the sixth terminal portion 43 is the same as the base metal of the second tab 13.

[0369] The fourth terminal portion 41 can include a first plate 41e and a second plate 41f. The second plate 41f is fixed to the first plate 41e, and the second through hole 414 penetrates the second plate 41f and the first plate 41e. As an example, the first plate 41e is provided with a recess, and the second plate 41f is accommodated in the recess.

[0370] The base metal of the first plate 41e and the base metal of the second plate 41f are different. The base metal of the second plate 41f is the same as the base metal of the sixth terminal portion 43. Optionally, the fourth terminal portion 41 is a copper-aluminum composite plate.

[0371] The base metal of the first plate 41e is the same as the base metal of the second bus component 7b, facilitating welding. The base metal of the first terminal portion 31 is the same as the base metal of the first bus component 7a, facilitating welding. The first bus component 7a and the second bus component 7b are made of the same material.

[0372] Compared with aluminum, copper has a smaller resistivity and a stronger heat conduction capacity. Compared with the second tab 13, the first tab 12 is more likely to generate heat and slower to conduct heat outward; therefore, heat exchange between the heat exchange member 9 and the first terminal portion 31 can improve the speed of heat dissipation of the first tab 12 outward, reduce the temperature difference between the first tab 12 and the second tab 13, and improve the cycle performance of the battery monomer 6.

[0373] Optionally, in the first direction X, the length of the first tab 12 is greater than the length of the second tab 13. By increasing the length of the first tab 12, the flow area of the first tab 12 can be increased, the resistance of the first tab 12 can be reduced, the heat generation of the aluminum first tab 12 can be reduced, and the temperature difference between the first tab 12 and the second tab 13 can be reduced.

[0374] Optionally, in the first direction X, the ratio of the length of the first tab 12 to the length of the first wall portion 20a is 0.3-0.5.

[0375] Optionally, the area of the first solder print 80a is greater than the area of the second solder print 80b.

[0376] Optionally, the length of the first solder print 80a is greater than the length of the second solder print 80b.

[0377] In some embodiments, the projection area of the second terminal portion 32 in the thickness direction thereof is greater than the projection area of the fifth terminal portion 42 in the thickness direction thereof.

[0378] Compared with the fifth terminal portion 42, the second terminal portion 32 can have a larger flow area, thereby reducing the heat generation of the second terminal portion 32.

[0379] The first terminal portion 31 has a large area to achieve heat exchange with the heat exchange member 9. The second terminal portion 32 is provided to have a large area, which can reduce the difference in strength between the first terminal portion 31 and the second terminal portion 32, reduce the deformation of the second terminal portion 32 when the battery cell 6 is subjected to external impact, and improve the stability of the fixation of the first electrode terminal 30 to the first wall portion 20a.

[0380] As an example, the base metal of the second terminal portion 32 is aluminum, and the base metal of the fifth terminal portion 42 is copper. By increasing the area of the second terminal portion 32, the difference in current-carrying capacity between the second terminal portion 32 and the fifth terminal portion 42 can be reduced.

[0381] In some embodiments, the projected area of the second terminal portion 32 along the thickness direction thereof is 1.2-5 times the projected area of the fifth terminal portion 42 along the thickness direction thereof.

[0382] Optionally, the projected area of the second terminal portion 32 along the thickness direction thereof is 1.2 times, 1.5 times, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times, or 5 times the projected area of the fifth terminal portion 42 along the thickness direction thereof.

[0383] Optionally, the projected area of the second terminal portion 32 along the thickness direction thereof is 2-3 times the projected area of the fifth terminal portion 42 along the thickness direction thereof.

[0384] The embodiments of the present application can balance the current-carrying capacity of the first electrode terminal 30 and the current-carrying capacity of the second electrode terminal 40 to some extent, and improve the cycle performance of the battery cell 6.

[0385] In some embodiments, the battery cell 6 can be charged at a charge rate of 2C-6C.

[0386] In some embodiments, the charging time of the battery cell 6 from 10% SOC to 80% SOC under room temperature conditions is less than or equal to 10.5 minutes.

[0387] As an example, the room temperature can be an ambient temperature of 30°C.

[0388] The SOC refers to the state of charge of the battery cell 6.

[0389] Exemplarily, 100% SOC and 0% SOC are defined as follows: the battery cell 6 is charged to a battery upper limit voltage at a constant current charging rate of 0.33C, and then charged at a constant voltage to 0.05C, corresponding to the state of 100% SOC of the battery cell; the battery cell 6 is discharged to a cut-off voltage at a constant current discharging rate of 0.33C, corresponding to the state of 0% SOC of the battery cell. Exemplarily, the battery upper limit voltage and the discharge cut-off voltage can be marked on the outer packaging film of the battery cell.

[0390] Exemplarily, the charging time of the battery cell 6 from 10% SOC to 80% SOC is 10.5 min, 10 min, 9.5 min, 9 min, 8.5 min, 8 min, 7.5 min, 7 min, 6.5 min, 6 min, 5.5 min, 5 min, or a range composed of any two of the above values.

[0391] In the embodiments of the present application, the battery cell 6 has a fast charging capability, which can save charging time and improve user experience. In the fast charging process of the battery cell 6, the first terminal part can exchange heat with the heat exchange member, thereby reducing the temperature rise of the battery cell 6 and reducing the risk of thermal runaway of the battery cell.

[0392] FIG. 12 is a structural schematic diagram of an end cover assembly provided by some embodiments of the present application; and FIG. 13 is a top view of the end cover assembly shown in FIG. 12. As an example, in FIG. 13, the first region and the second region are shown by diagonal lines.

[0393] Referring to FIGS. 12 and 13, in some embodiments, the first region 31a and the second region 31b are flushly arranged. The embodiments of the present application can reduce the forming difficulty of the first terminal part 31 and improve the flatness of the first terminal part 31.

[0394] In some embodiments, the surface of the first terminal part 31 away from the first wall part 20a can be a plane.

[0395] In some embodiments, the first terminal part 31 is a rectangular flat plate structure.

[0396] In some embodiments, the area of the second region 31b is greater than the area of the first region 31a.

[0397] In some embodiments, the first electrode terminal 30 includes two third terminal parts 33.

[0398] In some embodiments, the first terminal part 31 is symmetrical about a plane perpendicular to the first direction X.

[0399] In some embodiments, the fourth terminal part 41 does not overlap with the heat exchange member in the thickness direction Z.

[0400] In some embodiments, the projected area of the first terminal portion 31 along the thickness direction thereof is 2-4 times the projected area of the fourth terminal portion 41 along the thickness direction thereof.

[0401] In some embodiments, W2 is equal to W3.

[0402] In some embodiments, L2 / L3 is 2-5, optionally 3-4.

[0403] In some embodiments, the first electrode terminal 30 is a positive electrode terminal.

[0404] FIG. 14 is a structural schematic view of an end cover assembly of a battery cell according to some embodiments of the present application.

[0405] Referring to FIG. 14, in some embodiments, the first portion 311 and the second portion 312 are arranged along the first direction X, the size W21 of the first portion 311 along the second direction Y is smaller than the size W22 of the second portion 312 along the second direction Y, and the thickness direction Z, the first direction X and the second direction Y of the first wall portion 20a are perpendicular to each other.

[0406] The thickness of the first portion 311 can be greater than, equal to, or smaller than the thickness of the second portion 312.

[0407] In the first direction X, the size of the first portion 311 can be greater than, equal to, or smaller than the size of the second portion 312.

[0408] The second portion 312 has a larger size in the second direction Y, which can increase the heat exchange area of the second portion 312 with the heat exchange member, further improve the heat exchange efficiency, and improve the cycle performance of the battery cell 6.

[0409] In some embodiments, the thickness of the second portion 312 is smaller than the thickness of the first portion 311. Optionally, the first terminal portion 31 is provided with a first recess 313 recessed away from the surface of the first wall portion 20a relative to the first portion 311.

[0410] In some embodiments, the size L22 of the second portion 312 along the first direction X can be greater than the size L21 of the first portion 311 along the first direction X, so as to further increase the heat exchange area.

[0411] In some embodiments, the size W22 of the second portion 312 in the second direction Y is greater than the width W3 of the fourth terminal portion 41.

[0412] Optionally, the size W21 of the first portion 311 in the second direction Y is equal to the width W3 of the fourth terminal portion 41.

[0413] FIG. 15 is a structural schematic view of an end cover assembly of a battery cell according to some embodiments of the present application.

[0414] Referring to FIG. 15, in some embodiments, the first portion 311 and the second portion 312 are spaced apart along a first direction X, which is perpendicular to a thickness direction Z of the first wall portion 20a.

[0415] The first portion 311 and the second portion 312 can be independently formed, which is conducive to the processing and forming of parts, and can also eliminate the size restrictions caused by manufacturing capacity limitations, provide a larger area of the second portion 312, and thus improve the heat exchange effect.

[0416] In some embodiments, the first portion 311 is connected to the second terminal portion by at least one third terminal portion 33, and the second portion 312 is connected to the second terminal portion by at least one third terminal portion 33.

[0417] The two third terminal portions 33 can respectively fix the first portion 311 and the second portion 312 to the first wall portion 20a, so as to keep the relative positions of the first portion 311 and the second portion 312 fixed. The heat of the first portion 311 can be conducted to the second portion 312 through the third terminal portion 33 and the second terminal portion, so as to quickly dissipate heat.

[0418] In some embodiments, the thickness of the second portion 312 can be smaller than the thickness of the first portion 311.

[0419] Optionally, the surface of the first portion 311 facing the first wall portion 20a is flush with the surface of the second portion 312 facing the first wall portion 20a.

[0420] In some embodiments, the first portion 311 and the second portion 312 are the same in shape and size. The first portion 311 and the second portion 312 are the same components, which can save costs and reduce assembly difficulty.

[0421] In some embodiments, the area of the second portion 312 is greater than the area of the fourth terminal portion 41.

[0422] FIG. 16 is a structural schematic diagram of an end cover assembly of a battery cell according to some embodiments of the present application; and FIG. 17 is a cross-sectional schematic diagram of the end cover assembly shown in FIG. 16.

[0423] Referring to FIGS. 16 and 17, in some embodiments, the third terminal portion 33 is configured such that the third terminal portion 33 does not overlap the heat exchange member in the thickness direction Z.

[0424] The third terminal portion 33 is arranged away from the heat exchange member in the embodiments of the present application, which can reduce the risk of interference between the third terminal portion 33 and the heat exchange member, and improve the flatness of the heat exchange interface between the first terminal portion 31 and the heat exchange member.

[0425] In some embodiments, the first through hole 314 is one.

[0426] In some embodiments, the first region 31a and the second region 31b are respectively located on two sides of the first through hole 314 along the first direction X.

[0427] In some embodiments, the first terminal portion 31 includes a first edge 31c and a second edge 31d oppositely arranged along the first direction X, which is parallel to the length direction of the first wall portion 20a. In the first direction X, the minimum distance D4 between the axis of the first through hole 314 and the first edge 31c is equal to the minimum distance D5 between the axis of the first through hole 314 and the second edge 31d.

[0428] The embodiments of the present application centrally arrange the first through hole 314 and the third terminal portion 33, which can improve the structural strength of the first electrode terminal 30 and reduce the risk of deformation of the first terminal portion 31.

[0429] In some embodiments, the second electrode terminal 40 includes a fourth terminal portion 41 located on the outer side of the shell 20, which is used to connect the second busbar component of the battery and exchange heat with the heat exchange member.

[0430] In the cycle process of the battery 2, both the first terminal portion 31 and the fourth terminal portion 41 can exchange heat with the heat exchange member, thereby further improving the heat dissipation capacity of the battery monomer 6, reducing the temperature rise of the battery monomer 6, improving the cycle performance and cycle life of the battery monomer 6, and reducing the risk of thermal runaway of the battery monomer 6 in the rapid charging process. The second electrode terminal 40 is connected with the second tab, and the heat of the second tab can also be conducted to the heat exchange member through the fourth terminal portion 41, thereby reducing the temperature rise of the electrode assembly and improving the cycle performance and cycle life of the battery monomer 6. The fourth terminal portion 41 can simultaneously play the roles of heat dissipation and current transmission, which helps to shorten the heat transfer path between the heat source and the heat exchange member and improve the heat dissipation efficiency.

[0431] In some embodiments, the surface of the fourth terminal portion 41 away from the shell 20 is configured to be connected with the heat exchange member. As an example, the surface of the fourth terminal portion 41 away from the shell 20 can be a flat surface or a stepped surface.

[0432] In some embodiments, the second electrode terminal 40 is arranged on the first wall portion 20a. The second welding mark 80b is configured to at least partially overlap with the heat exchange member in the thickness direction Z of the first wall portion 20a.

[0433] In some embodiments, the second electrode terminal 40 is disposed on the first wall portion 20a. The surface of the first terminal portion 31 away from the first wall portion 20a includes a first region 31a and a second region 31b, the first region 31a is configured to overlap and connect with the first bus member in the thickness direction Z of the first wall portion 20a. The surface of the fourth terminal portion 41 away from the first wall portion 20a includes a third region 41a and a fourth region 41b, the third region 41a is configured to overlap and connect with the second bus member in the thickness direction Z. The second region 31b and the fourth region 41b are configured to overlap with the heat exchange member in the thickness direction Z.

[0434] As an example, the third region 41a is disposed in abutment with the second bus member.

[0435] As an example, in the thickness direction Z, the projection of the fourth region 41b is located within the projection of the heat exchange member.

[0436] The third region 41a and the fourth region 41b can be flush or offset in the thickness direction Z of the first wall portion 20a.

[0437] The third region 41a and the fourth region 41b can be directly connected or spaced apart.

[0438] In some embodiments, the area of the fourth region 41b is greater than the area of the third region 41a. The larger area of the fourth region 41b can improve the heat exchange efficiency between the heat exchange member and the fourth terminal portion 41, reduce the temperature rise of the fourth terminal portion 41, and improve the cycle performance and reliability of the battery cell 6.

[0439] In some embodiments, the third region 41a and the fourth region 41b are respectively located on both sides of the second through hole 414 along the first direction X.

[0440] In some embodiments, the fourth terminal portion 41 has a third edge 41c and a fourth edge 41d at both ends along the first direction X, and in the second direction Y, the minimum distance between the axis of the second through hole 414 and the third edge 41c is equal to the minimum distance between the axis of the second through hole 414 and the fourth edge 41d.

[0441] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the second electrode terminal 40 is a negative electrode terminal. The area of the second region 31b is greater than the area of the fourth region 41b. The first tab and the first electrode terminal 30 are both copper, while the second tab is copper and a portion of the second electrode terminal 40 is copper. The first tab and the first electrode terminal 30 generate more heat. By setting the second region 31b to be larger than the fourth region 41b, the heat exchange efficiency between the first electrode terminal 30 and the heat exchange member can be improved, and the temperature difference between the first tab and the second tab can be reduced.

[0442] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the second electrode terminal 40 is a negative electrode terminal. The ratio of (L2 x W2) to (L3 x W3) is 1.2-5, or 2-3.

[0443] In some embodiments, the first region 31a, the second region 31b, the fourth region 41b, and the third region 41a are sequentially and spacedly arranged along the first direction X, and the first direction X is perpendicular to the thickness direction Z.

[0444] The second region 31b and the fourth region 41b are adjacently arranged along the first direction X, and the same heat exchange member can simultaneously exchange heat with the second region 31b and the fourth region 41b, thereby simplifying the structure of the battery.

[0445] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the fourth terminal portion 41 is 0.2-0.5 times the projected area of the first wall portion 20a.

[0446] FIG. 18 is a top view of an end cover assembly of a battery cell according to some embodiments of the present application.

[0447] Referring to FIG. 18, in some embodiments, the second region 31b, the first region 31a, the third region 41a, and the fourth region 41b are sequentially and spacedly arranged along the first direction X, and the first direction X is perpendicular to the thickness direction Z.

[0448] When a plurality of battery cells 6 are arranged along the first direction X, the second region 31b of one battery cell 6 is adjacent to the fourth region 41b (or the second region 31b) of another battery cell 6, and the same heat exchange member can simultaneously exchange heat with the two battery cells 6, thereby simplifying the structure of the battery 2.

[0449] In some embodiments, in the first direction X, the minimum distance D4 between the axis of the first through hole 314 and the first edge 31c is less than the minimum distance D5 between the axis of the first through hole 314 and the second edge 31d, the portion of the first terminal portion 31 between the first edge 31c and the first through hole 314 is used for connecting with the first bus member, and the portion of the first terminal portion 31 between the second edge 31d and the first through hole 314 is used for exchanging heat with the heat exchange member.

[0450] For example, at least part of the first region 31a is located between the first edge 31c and the first through hole 314, and at least part of the second region 31b is located between the second edge 31d and the first through hole 314.

[0451] The first through hole 314 is eccentrically designed in the embodiment, a larger area can be reserved for heat exchange with the heat exchange member, so as to improve the heat exchange efficiency. The embodiment can also reduce the distance between the third terminal part 33 and the first bus member, shorten the conductive path, reduce the resistance, and reduce heat generation.

[0452] FIG. 19 is a structural schematic diagram of an end cover assembly of a battery cell provided by some other embodiments of the application.

[0453] Referring to FIG. 19, in some embodiments, the second electrode terminal 40 includes a plurality of sixth terminal parts 43 arranged at intervals. By arranging a plurality of sixth terminal parts 43, the overcurrent capacity can be improved, heat generation can be reduced, the structural strength of the second electrode terminal 40 can be improved, and the stability of the connection between the second electrode terminal 40 and the shell 20 can be improved.

[0454] In some embodiments, the second electrode lead-out hole is a plurality of second electrode lead-out holes, and the plurality of second electrode lead-out holes are arranged one by one corresponding to the plurality of sixth terminal parts 43.

[0455] In some embodiments, the fourth terminal part 41 includes a third part 411 and a fourth part 412, the third part 411 is configured to be connected to the second bus member, and the fourth part 412 is configured to be connected to the heat exchange member.

[0456] The thickness of the third part 411 and the thickness of the fourth part 412 can be the same or different.

[0457] In the first direction X, the size of the third part 411 and the size of the fourth part 412 can be the same or different; in the second direction Y, the size of the third part 411 and the size of the fourth part 412 can be the same or different.

[0458] The third part 411 and the fourth part 412 can be arranged in connection or in separation.

[0459] In some embodiments, the third part 411 is connected to the fifth terminal part 42 through at least one sixth terminal part 43, and the fourth part 412 is connected to the fifth terminal part 42 through at least one sixth terminal part 43.

[0460] In some embodiments, the third part 411 is configured to at least partially overlap and connect with the second bus member in the thickness direction Z of the first wall part 20a, and the fourth part 412 is configured to at least partially overlap the heat exchange member in the thickness direction Z.

[0461] In some embodiments, the second bus member is arranged on the side of the third part 411 away from the first wall part 20a and is connected to the third part 411.

[0462] In some embodiments, the heat exchange member is arranged on a side of the fourth portion 412 away from the first wall portion 20a.

[0463] In some embodiments, the third portion 411 comprises a third region 41a. The fourth portion 412 comprises a fourth region 41b.

[0464] In some embodiments, the thickness of the third portion 411 is greater than or equal to the thickness of the fourth portion 412. Alternatively, the thickness of the third portion 411 is greater than the thickness of the fourth portion 412.

[0465] In some embodiments, the thickness of the third portion 411 is greater than or equal to 3mm.

[0466] In some embodiments, the thickness of the third portion 411 is equal to the thickness of the first portion 311, and the thickness of the fourth portion 412 is equal to the thickness of the second portion 312.

[0467] In some embodiments, the ratio of the thickness of the third portion 411 to the thickness of the fourth portion 412 is 1.2-3, which can be 1.2, 1.5, 2, 2.5 or 3.

[0468] In some embodiments, the third portion 411 extends beyond the fourth portion 412 in a direction away from the first wall portion 20a.

[0469] In some embodiments, the fourth terminal portion 41 has a second recess 413 on a side away from the first wall portion 20a, and the fourth portion 412 is a bottom wall of the second recess 413.

[0470] In some embodiments, the second busbar member is laser welded with the third portion 411.

[0471] In some embodiments, the second recess 413 is located on a side of the third portion 411 along the first direction X. An end of the second recess 413 away from the third portion 411 along the first direction X can extend to an edge of the fourth terminal portion 41.

[0472] In some embodiments, along the second direction Y, the second recess 413 penetrates through the fourth terminal portion 41.

[0473] In some embodiments, in the thickness direction Z of the first wall portion 20a, the depth of the second recess 413 is 0.1mm-2mm.

[0474] In some embodiments, the depth of the second recess 413 is equal to the depth of the first recess 313.

[0475] In some embodiments, as viewed from the thickness direction Z, the area of the fourth portion 412 is greater than the area of the third portion 411, so that the heat exchange area between the fourth terminal portion 41 and the heat exchange member is larger.

[0476] In some embodiments, the third portion 411 and the fourth portion 412 are arranged along the first direction X, and the size of the third portion 411 along the second direction Y is less than or equal to the size of the fourth portion 412 along the second direction Y. Alternatively, the size of the third portion 411 along the second direction Y is less than the size of the fourth portion 412 along the second direction Y.

[0477] In some embodiments, the size of the third portion 411 along the second direction Y is equal to the size of the first portion 311 along the second direction Y. The size of the fourth portion 412 along the second direction Y is equal to the size of the second portion 312 along the second direction Y.

[0478] In some embodiments, the third portion 411 and the fourth portion 412 can be arranged continuously along the first direction X or can be arranged spaced apart along the first direction X.

[0479] In some embodiments, the size of the third portion 411 along the first direction X is less than or equal to the size of the fourth portion 412 along the second direction Y. Alternatively, the size of the third portion 411 along the first direction X is less than the size of the fourth portion 412 along the first direction X.

[0480] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the second electrode terminal 40 is a negative electrode terminal. In the thickness direction Z of the first wall portion 20a, the projected area of the second portion 312 is greater than or equal to the projected area of the fourth portion 412, and the projected area of the first portion 311 is greater than or equal to the projected area of the third portion 411.

[0481] Alternatively, in the thickness direction Z of the first wall portion 20a, the projected area of the second portion 312 is greater than the projected area of the fourth portion 412, and the projected area of the first portion 311 is greater than the projected area of the third portion 411.

[0482] In some embodiments, in the first direction X, the size of the second portion 312 is greater than the size of the fourth portion 412.

[0483] In some embodiments, in the first direction X, the first portion 311, the second portion 312, the fourth portion 412, and the third portion 411 are arranged in sequence. The second portion 312 and the fourth portion 412 are arranged adjacent to each other along the first direction X, and the same heat exchange member can exchange heat with the second portion 312 and the fourth portion 412 at the same time, thereby simplifying the structure of the battery.

[0484] FIG. 20 is a structural schematic diagram of an end cover assembly of a battery cell according to some embodiments of the present application.

[0485] Referring to FIG. 20, in some embodiments, the third portion 411 and the fourth portion 412 can be arranged spaced apart along the first direction X.

[0486] Optionally, the third portion 411 is connected to the fifth terminal portion 42 through a sixth terminal portion 43, and the fourth portion 412 is connected to the fifth terminal portion 42 through a sixth terminal portion 43.

[0487] Optionally, the third portion 411 and the fourth portion 412 are both copper-aluminum composite plates.

[0488] In some embodiments, the second portion 312, the first portion 311, the third portion 411 and the fourth portion 412 are sequentially arranged in the first direction X. When a plurality of battery monomers 6 are arranged along the first direction X, the second portion 312 of one battery monomer 6 is adjacent to the fourth portion 412 (or the second portion 312) of another battery monomer 6, and the same heat exchange member can simultaneously exchange heat with two battery monomers 6, thereby simplifying the structure of the battery.

[0489] In some embodiments, the thickness of the fourth portion 412 is less than the thickness of the third portion 411.

[0490] FIG. 21 is a simplified schematic diagram of a battery monomer provided by some embodiments of the present application.

[0491] Referring to FIG. 21, in some embodiments, the shell 20 includes a second wall portion 20b, which is arranged opposite to the first wall portion 20a, and the second electrode terminal 40 is arranged on the second wall portion 20b.

[0492] Arranging the first electrode terminal 30 and the second electrode terminal 40 on the first wall portion 20a and the second wall portion 20b respectively can enable the first terminal portion 31 to have a larger area, thereby improving the heat exchange efficiency and the overcurrent capacity and improving the cycle performance of the battery monomer 6.

[0493] Arranging the first electrode terminal 30 and the second electrode terminal 40 on opposite ends of the shell 20 can also reduce the risk of short circuit.

[0494] In some embodiments, the first electrode terminal 30 includes a first portion 311 and a second portion 312, and the first portion 311 and the second portion 312 are arranged apart along the first direction X.

[0495] In some embodiments, the second electrode terminal 40 includes a third portion 411 and a fourth portion 412, and the third portion 411 and the fourth portion 412 are arranged apart along the first direction X.

[0496] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projection area of the first terminal portion 31 is S1, and the projection area of the first wall portion 20a is S3. S1 and S3 satisfy: 0.2≤S1 / S3≤0.8; optionally, 0.3≤S1 / S3≤0.5.

[0497] S1 / S3 is greater than or equal to 0.3, the first terminal portion 31 can have a larger area, thereby improving the heat dissipation capacity and overcurrent capacity of the first electrode terminal 30, and improving the cycle performance of the battery cell 6. S1 / S3 is less than or equal to 0.8, installation space can be reserved for other components, and the influence of increasing the first terminal portion 31 on the energy density of the battery cell 6 is reduced.

[0498] In some embodiments, in the thickness direction Z of the first wall portion 20a, the fourth terminal portion 41 has a projected area S2, and the first wall portion 20a has a projected area S3. S2 and S3 satisfy: 0.2≤S2 / S3≤0.8; optionally, 0.3≤S2 / S3≤0.5.

[0499] S2 / S3 is greater than or equal to 0.3, the fourth terminal portion 41 can have a larger area, thereby improving the heat dissipation capacity and overcurrent capacity of the second electrode terminal 40, and improving the cycle performance of the battery cell 6. S2 / S3 is less than or equal to 0.8, installation space can be reserved for other components, and the influence of increasing the fourth terminal portion 41 on the energy density of the battery cell 6 is reduced.

[0500] In some embodiments, the battery cell 6 can be provided with heat exchange members on both sides. The heat exchange member on one side of the battery cell 6 exchanges heat with the first electrode terminal 30, and the heat exchange member on the other side of the battery cell 6 exchanges heat with the second electrode terminal 40.

[0501] FIG. 22 is a cross-sectional view of a battery according to some embodiments of the present application.

[0502] Referring to FIG. 22, in some embodiments, the battery 2 includes a battery cell 6, a first busbar component 7a, and a heat exchange member 9. The first busbar component 7a is connected to the first terminal portion 31. At least part of the heat exchange member 9 is located on the side of the first wall portion 20a away from the electrode assembly and exchanges heat with the first terminal portion 31.

[0503] In some embodiments, the battery 2 further includes a second busbar component 7b connected to the fourth terminal portion 41.

[0504] In some embodiments, in the thickness direction Z of the first wall portion 20a, part of the first terminal portion 31 is located between the heat exchange member 9 and the first wall portion 20a.

[0505] The heat exchange member 9 can exchange heat with the first terminal portion 31, thereby improving the heat dissipation efficiency of the battery cell 6 and improving the cycle performance of the battery cell 6.

[0506] In some embodiments, the battery 2 includes a box 5, and the battery cell 6 and the first busbar component 7a are accommodated in the box 5.

[0507] In some embodiments, the plurality of battery cells 6 are accommodated in the case 5.

[0508] In some embodiments, the heat exchange member 9 is arranged outside the case 5, which can save the internal space of the case 5 and improve the space utilization.

[0509] In some embodiments, the heat exchange member 9 exchanges heat with the first electrode terminal 30 and the second electrode terminal 40 through the case wall of the case 5.

[0510] In some embodiments, the case wall and the first terminal part 31 of the first electrode terminal 30 are bonded by the insulating heat-conductive adhesive 9a.

[0511] In some embodiments, the case wall and the fourth terminal part 41 of the second electrode terminal 40 are bonded by the insulating heat-conductive adhesive 9a.

[0512] In some embodiments, the plurality of battery cells 6 are arranged along the first direction X.

[0513] In some embodiments, the heat exchange member 9 is a heat exchange pipe extending along the second direction Y.

[0514] Exemplarily, in the thickness direction Z of the first wall part 20a, one heat exchange pipe at least partially overlaps with the second part 312 of one battery cell 6, and the fourth part 412 of another battery cell 6 at least partially overlaps.

[0515] According to some embodiments of the present application, the present application also provides a power consuming device, which comprises the battery of any one of the above embodiments, and the battery is used to provide electric energy for the power consuming device. The power consuming device can be the device or system of any one of the above applications.

[0516] Referring to FIGS. 3-8 and 19, the embodiments of the present application provide a battery cell 6, which comprises a shell 20, an electrode assembly 10, a first electrode terminal 30, and a second electrode terminal 40.

[0517] The electrode assembly 10 is accommodated in the shell 20 and comprises first and second polar tabs 12 and 13 with opposite polarities.

[0518] The shell 20 comprises a first wall part 20a, which is provided with a first electrode lead-out hole 221 and a second electrode lead-out hole 222.

[0519] The first electrode terminal 30 includes a first terminal portion 31, a second terminal portion 32, and a third terminal portion 33. The first terminal portion 31 is located outside the first wall portion 20a, the second terminal portion 32 is located inside the first wall portion 20a and connected to the first tab 12, and at least a part of the third terminal portion 33 is accommodated in the first electrode lead-out hole 221, and the third terminal portion 33 connects the second terminal portion 32 and the first terminal portion 31. In the thickness direction Z of the first wall portion 20a, a part of the first wall portion 20a is located between the first terminal portion 31 and the second terminal portion 32.

[0520] The second electrode terminal 40 includes a fourth terminal portion 41, a fifth terminal portion 42, and a sixth terminal portion 43. The fourth terminal portion 41 is located outside the first wall portion 20a, the fifth terminal portion 42 is located inside the first wall portion 20a and connected to the second tab 13, and at least a part of the sixth terminal portion 43 is accommodated in the second electrode lead-out hole 222, and the sixth terminal portion 43 connects the fifth terminal portion 42 and the fourth terminal portion 41. In the thickness direction Z of the first wall portion 20a, a part of the first wall portion 20a is located between the fourth terminal portion 41 and the fifth terminal portion 42.

[0521] The first terminal portion 31 includes a first part 311 and a second part 312 arranged in the first direction X, and the thickness of the first part 311 is greater than the thickness of the second part 312. The first terminal portion 31 has a first recess 313 on the side away from the first wall portion 20a, and the second part 312 is the bottom wall of the first recess 313. The third terminal portion 33 is two, and the two third terminal portions 33 are respectively connected to the first part 311 and the second part 312.

[0522] The fourth terminal portion 41 includes a third part 411 and a fourth part 412 arranged in the first direction X, and the thickness of the third part 411 is greater than the thickness of the fourth part 412. The fourth terminal portion 41 has a second recess 413 on the side away from the first wall portion 20a, and the fourth part 412 is the bottom wall of the second recess 413. The sixth terminal portion 43 is two, and the two sixth terminal portions 43 are respectively connected to the third part 411 and the fourth part 412.

[0523] The first part 311, the second part 312, the fourth part 412, and the third part 411 are arranged in the first direction X.

[0524] The first part 311 is used to be connected to the first bus member 7a of the battery 2, and the third part 411 is used to be connected to the second bus member 7b of the battery 2. The second part 312 and the fourth part 412 are used to exchange heat with the heat exchange member 9.

[0525] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0526] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application, and are not intended to limit the same; although the present application has been described in detail with reference to the foregoing examples, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacements for some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, comprising: a housing including a first wall portion; an electrode assembly accommodated in the housing, the electrode assembly including a first tab; and a first electrode terminal disposed at the first wall portion and electrically connected to the first tab, the first electrode terminal including a first terminal portion outside the first wall portion, the first terminal portion being configured to connect to a first busbar of a battery and exchange heat with a heat exchange member of the battery.

2. The battery cell of claim 1, wherein, The first terminal portion includes a first portion configured to connect to the first busbar and a second portion configured to exchange heat with the heat exchange member.

3. The battery cell of claim 2, wherein, The first portion is configured to at least partially overlap and connect to the first busbar in a thickness direction of the first wall portion, and the second portion is configured to at least partially overlap the heat exchange member in the thickness direction.

4. The battery cell of claim 2 or 3, wherein, The first portion has a thickness greater than a thickness of the second portion.

5. The battery cell of any one of claims 2-4, wherein, The first portion extends beyond the second portion in a direction away from the first wall portion.

6. The battery cell of any one of claims 2-5, wherein, A first recess is formed on a side of the first terminal portion away from the first wall portion, and the second portion is a bottom wall of the first recess.

7. The battery cell of claim 6, wherein, In the thickness direction of the first wall portion, the first recess has a depth of 0.1 mm to 2 mm.

8. The battery cell of any one of claims 2-7, wherein, The first portion and the second portion are disposed in a first direction, a dimension of the first portion in a second direction is less than a dimension of the second portion in the second direction, and the thickness direction of the first wall portion, the first direction, and the second direction are perpendicular to each other.

9. The battery cell of any one of claims 2-8, wherein, The first portion and the second portion are spaced apart in a first direction perpendicular to the thickness direction of the first wall portion.

10. The battery cell of any one of claims 2-9, wherein, The first portion and the second portion are disposed in a first direction perpendicular to the thickness direction of the first wall portion. In the first direction, the second portion has a dimension greater than a dimension of the first portion.

11. The battery cell of any one of claims 1-10, wherein, A surface of the first terminal portion away from the first wall portion is configured to connect to the heat exchange member.

12. The battery cell of any one of claims 1-11, wherein, The surface of the first terminal portion away from the first wall portion includes a first region configured to connect to the first busbar and a second region configured to be disposed opposite the heat exchange member in a thickness direction of the first wall portion.

13. The battery cell of claim 12, wherein, The first region and the second region are spaced apart.

14. The battery cell of claim 12 or 13, wherein, An area of the second region is greater than an area of the first region.

15. The battery cell of any one of claims 12-14, wherein, A ratio of the area of the first region to a projection area of the first terminal portion in the thickness direction is greater than or equal to 1.5%.

16. The battery cell of any one of claims 12-15, wherein, A ratio of the area of the second region to the projection area of the first terminal portion in the thickness direction is greater than or equal to 10%.

17. The battery cell of any one of claims 1-16, wherein, The first wall portion is provided with a first electrode lead-out hole. The first electrode terminal further includes a second terminal portion inside the first wall portion and electrically connected to the first tab, and a third terminal portion at least partially accommodated in the first electrode lead-out hole and connecting the second terminal portion and the first terminal portion. In the thickness direction of the first wall portion, a portion of the first wall portion is located between the first terminal portion and the second terminal portion.

18. The battery cell of claim 17, wherein, The second terminal portion and the third terminal portion are integrally formed.

19. The battery cell of claim 17 or 18, wherein, The first terminal portion is provided with a first through hole penetrating the first terminal portion along a thickness direction of the first wall portion; A part of the third terminal portion is accommodated in the first through hole and connected to the first terminal portion.

20. The battery cell of claim 19, wherein, In the thickness direction, an end of the third terminal portion away from the second terminal portion does not exceed the first through hole.

21. The battery cell of claim 19 or 20, wherein, The third terminal portion is configured such that the third terminal portion does not overlap the heat exchange member in the thickness direction.

22. The battery cell of any one of claims 19-21, wherein, The first terminal portion includes a first edge and a second edge oppositely arranged along a first direction, the first direction being parallel to a length direction of the first wall portion; In the first direction, a minimum distance between an axis of the first through hole and the first edge is equal to a minimum distance between the axis of the first through hole and the second edge; or, in the first direction, a minimum distance between the axis of the first through hole and the first edge is smaller than a minimum distance between the axis of the first through hole and the second edge, a part of the first terminal portion between the first edge and the first through hole being used for connecting with the first bus member, and a part of the first terminal portion between the second edge and the first through hole being used for heat exchange with the heat exchange member.

23. The battery cell of any one of claims 17-21, wherein, The first electrode terminal includes a plurality of third terminal portions arranged at intervals.

24. The battery cell of claim 23, wherein, The first terminal portion includes a first part and a second part arranged at intervals along a first direction, the first direction being perpendicular to a thickness direction of the first wall portion; The first part is connected to the second terminal portion through at least one of the third terminal portions, and the second part is connected to the second terminal portion through at least one of the third terminal portions.

25. The battery cell of claim 23, wherein, The first terminal portion includes a first edge and a second edge oppositely arranged along a first direction, the first direction being parallel to a length direction of the first wall portion; The first terminal portion is provided with two first through holes arranged at intervals along the first direction, and two third terminal portions are respectively arranged in the two first through holes and connected to the first terminal portion; In the first direction, a distance between the first edge and an axis of the first through hole close to the first edge is D1, a distance between the second edge and an axis of the first through hole close to the second edge is D2, and a distance between the axes of the two first through holes is D3; D1 / D2 is 0.9-1.1, and (D1+D2) / D3 is 0.9-1.

1.

26. The battery cell of any one of claims 17-25, wherein, A cross section of the third terminal portion perpendicular to the thickness direction of the first wall portion is circular, elliptical or track-shaped.

27. The battery cell of any one of claims 17-26, wherein, The first tab is welded to the second terminal portion and forms a first welding mark.

28. The battery cell of claim 27, wherein, The first welding mark is configured to at least partially overlap the heat exchange member in the thickness direction of the first wall portion.

29. The battery cell of any one of claims 17-28, wherein, In the thickness direction of the first wall portion, a projection area of the first terminal portion is greater than a projection area of the second terminal portion.

30. The battery cell of any one of claims 17-29, wherein, In the thickness direction of the first wall portion, the projection area of the second terminal portion is 0.2-0.5 times the projection area of the first wall portion.

31. The battery cell of any one of claims 1-30, wherein, The first terminal portion has a projected area in the thickness direction of the first wall portion that is 0.2-0.5 times the projected area of the first wall portion.

32. The battery cell of any one of claims 1-31, wherein, The electrode assembly further includes a second tab, the first tab and the second tab being opposite in polarity; The battery cell further includes a second electrode terminal disposed on the housing, the second electrode terminal being electrically connected to the second tab.

33. The battery cell of claim 32, wherein, The second electrode terminal includes a fourth terminal portion located on the outside of the housing, the fourth terminal portion being configured to connect to a second bus member of the battery and exchange heat with the heat exchange member.

34. The battery cell of claim 33, wherein, The second electrode terminal is disposed on the first wall portion; The surface of the first terminal portion away from the first wall portion includes a first region and a second region, the first region being configured to overlap and connect to the first bus member in the thickness direction of the first wall portion; The surface of the fourth terminal portion away from the first wall portion includes a third region and a fourth region, the third region being configured to overlap and connect to the second bus member in the thickness direction; The second region and the fourth region are configured to overlap the heat exchange member in the thickness direction; The second region, the first region, the third region, and the fourth region are arranged in sequence along a first direction, or the first region, the second region, the fourth region, and the third region are arranged in sequence along the first direction; The first direction is perpendicular to the thickness direction.

35. The battery cell of any one of claims 32-34, wherein, The second electrode terminal includes a fourth terminal portion located on the outside of the housing; The projected area of the first terminal portion in the thickness direction thereof is greater than the projected area of the fourth terminal portion in the thickness direction thereof.

36. The battery cell of claim 35, wherein, The projected area of the first terminal portion in the thickness direction thereof is 1.2-5 times the projected area of the fourth terminal portion in the thickness direction thereof, or the projected area of the first terminal portion in the thickness direction thereof is 2-3 times the projected area of the fourth terminal portion in the thickness direction thereof.

37. The battery cell of any one of claims 32-36, wherein, The housing is provided with a first electrode lead-out hole and a second electrode lead-out hole; The first electrode terminal further includes a second terminal portion and a third terminal portion, the second terminal portion being located on the inside of the first wall portion and electrically connected to the first tab, at least part of the third terminal portion being accommodated in the first electrode lead-out hole, and the third terminal portion connecting the second terminal portion and the first terminal portion; The second electrode terminal further includes a fourth terminal portion, a fifth terminal portion, and a sixth terminal portion, the fourth terminal portion being located on the outside of the housing, the fifth terminal portion being located on the inside of the housing and electrically connected to the second tab, at least part of the sixth terminal portion being accommodated in the second electrode lead-out hole, and the sixth terminal portion connecting the fifth terminal portion and the fourth terminal portion; The projected area of the second terminal portion in the thickness direction thereof is greater than the projected area of the fifth terminal portion in the thickness direction thereof.

38. The battery cell of claim 37, wherein, The second terminal portion has a projected area along a thickness direction thereof that is 1.2-5 times a projected area along a thickness direction of the fifth terminal portion, and optionally, the projected area along the thickness direction of the second terminal portion is 2-3 times the projected area along the thickness direction of the fifth terminal portion.

39. The battery cell of any one of claims 32-38, wherein, The second electrode terminal is disposed on the first wall portion, and the second electrode terminal includes a fourth terminal portion located outside the first wall portion. In a thickness direction of the first wall portion, a projected area of the first terminal portion is S1, a projected area of the fourth terminal portion is S2, and a projected area of the first wall portion is S3. S1, S2, and S3 satisfy 0.2≤(S1+S2) / S3≤0.8, and optionally, 0.3≤(S1+S2) / S3≤0.

5.

40. The battery cell of claim 32, wherein, The housing includes a second wall portion disposed opposite to the first wall portion, and the second electrode terminal is disposed on the second wall portion. In a thickness direction of the first wall portion, a projected area of the first terminal portion is S1, and a projected area of the first wall portion is S3. S1 and S3 satisfy 0.2≤S1 / S3≤0.8, and optionally, 0.3≤S1 / S3≤0.

5.

41. The battery cell of claim 32, wherein, The second electrode terminal is disposed on the first wall portion, and the second electrode terminal includes a fourth terminal portion located outside the first wall portion. In a thickness direction of the first wall portion, the fourth terminal portion does not overlap the heat exchange member.

42. The battery cell of any one of claims 1-41, wherein, The housing includes a second wall portion, and the battery cell includes a pressure relief mechanism disposed on the second wall portion.

43. The battery cell of any one of claims 1-42, wherein, The first electrode terminal is a positive electrode terminal, and a material of the first electrode terminal includes aluminum.

44. The battery cell of any one of claims 1-43, wherein, The first wall portion is provided with an electrolyte injection hole.

45. The battery cell of any one of claims 1-44, wherein, The housing includes a housing body having an opening and an end cover connected to the housing body and covering the opening. The end cover is the first wall portion.

46. A battery, comprising: The battery cell according to any one of claims 1-45; a first busbar member connected to the first terminal portion; and a heat exchange member, at least a portion of the heat exchange member being located on a side of the first wall portion facing away from the electrode assembly and in heat exchange with the first terminal portion. In a thickness direction of the first wall portion, a portion of the first terminal portion is located between the heat exchange member and the first wall portion.

47. The battery of claim 46, wherein, 48. The battery according to claim 46 or 47, further comprising a box body; The battery cell and the first busbar member are accommodated in the box body, and the heat exchange member is disposed outside the box body.

49. An electric device, comprising the battery according to any one of claims 46-48, the battery being configured to provide electric energy. ​

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