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), the first terminal portion (31) comprises a first main body portion (311) and a first thinned portion (312), and the thickness of the first main body portion (311) is greater than the thickness of the first thinned portion (312).

Description

Battery cell, battery and electric device TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, 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, which comprises 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 comprising a first main body portion and a first thinned portion, the thickness of the first main body portion being greater than the thickness of the first thinned portion.

[0007] The first main body portion has a greater thickness than the first thinned portion, which is not easy to be melted through when welded with other components, thereby improving the reliability of the battery cell. Exemplarily, the first main body portion can be used for welding with a first bus component. Since the first main body portion has a greater thickness, the welding strength can be increased, the overcurrent capacity can be improved, and the heat generation can be reduced. By arranging the first thinned portion, the exposed area of the first electrode terminal can be increased, thereby improving the heat dissipation capacity of the battery cell, reducing the temperature rise inside the battery cell, and improving the cycle performance of the battery cell. The first thinned portion has a smaller thickness, thereby reducing the influence of the added first thinned portion on the energy density of the battery cell.

[0008] In some embodiments, the first main body portion exceeds the first thinned portion in a direction away from the first wall portion.

[0009] In the thickness direction of the first wall portion, the surface of the first thinned portion away from the first wall portion is closer to the first wall portion than the surface of the first thinned portion away from the first wall portion, thereby reserving more space on the side of the first thinned portion away from the first wall portion to facilitate the arrangement of other components and improve the space utilization.

[0010] In some embodiments, the first terminal portion has a first recess away from one side of the first wall portion, and the first thinning portion is a bottom wall of the first recess.

[0011] By providing the first recess, space can be provided for other components of the battery, and the space utilization in the thickness direction of the first wall portion can be improved.

[0012] In some embodiments, the depth of the first recess in the thickness direction of the first wall portion is 0.1mm-2mm.

[0013] 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 space utilization. Limiting the depth of the first recess to be less than or equal to 2mm can reduce the risk of deformation of the first thinning portion when the battery cell is subjected to external impact, and improve the reliability of the battery cell.

[0014] In some embodiments, the first main body portion and the first thinning portion are arranged along a first direction, the size of the first main body portion along a second direction is less than the size of the first thinning portion along the second direction, and the thickness direction of the first wall portion, the first direction, and the second direction are perpendicular to each other.

[0015] The first thinning portion has a large size in the second direction, which can increase the exposed area of the first thinning portion, further improve the heat dissipation efficiency, and improve the cycle performance of the battery cell. The thickness of the first thinning portion is small, and increasing the size of the first thinning portion along the second direction has less impact on the energy density of the battery cell than increasing the size of the first main body portion along the second direction.

[0016] In some embodiments, the first main body portion and the first thinning portion are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the first wall portion. The first main body portion and the first thinning portion can be independently formed, which is beneficial for the processing and forming of parts, and can also eliminate the size restrictions caused by manufacturing capacity limitations, providing a larger area of the first thinning portion to improve heat dissipation.

[0017] In some embodiments, the first main body portion and the first thinning portion are arranged along a first direction, and the first direction is perpendicular to the thickness direction of the first wall portion. In the first direction, the size of the first thinning portion is greater than the size of the first main body portion.

[0018] The first thinning portion has a size greater than the first main body portion in the first direction, which can have a larger exposed area to improve heat dissipation efficiency, reduce the temperature rise inside the battery cell, and improve the cycle performance of the battery cell. The thickness of the first thinning portion is less than the thickness of the first main body portion, and increasing the size of the first thinning portion along the first direction has less impact on the volume and weight of the battery cell than increasing the size of the first main body portion along the first direction.

[0019] 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 connected to the second 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 at least one of the first main body portion and the first thinning portion is connected to the third terminal portion. In the thickness direction of the first wall portion, a part of the first wall portion is located between the first terminal portion and the second terminal portion.

[0020] 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.

[0021] In some embodiments, at least one of the first main body portion and the first thinning portion is provided with a first through hole, and the first through hole penetrates in the 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.

[0022] In 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.

[0023] 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 other components.

[0024] In some embodiments, the first thinning portion is used for heat exchange with a heat exchange member of the battery. The at least one third terminal portion is configured such that the third terminal portion is connected to the first thinning portion and at least partially overlaps with the heat exchange member in the thickness direction.

[0025] In the cycle process of the battery cell, the heat of the first tab is conducted to the first terminal portion through the second terminal portion and the third terminal portion. Overlapping the third terminal portion with the heat exchange member in the thickness direction can shorten the heat conduction path between the third terminal portion and the heat exchange member, and improve the heat exchange efficiency.

[0026] In some embodiments, the at least one third terminal portion is directly connected to the first main body portion, which can shorten the electric conduction path between the first tab and the first main body portion, reduce the resistance, and reduce the heat generation.

[0027] In some embodiments, the first electrode terminal includes a plurality of third terminal portions arranged at intervals.

[0028] The first main body portion is connected to the second terminal portion through the at least one third terminal portion, so as to shorten the electric conduction path between the first tab and the first main body portion. The first thinning portion is connected to the second terminal portion through the at least one third terminal portion, so as to shorten the heat conduction path between the first tab and the first thinning portion.

[0029] In some embodiments, the first main body part and the first thinning part are arranged along a first direction, the first direction being parallel to a length direction of the first wall part. The first main body part has a first edge at an end away from the first thinning part, and the first thinning part has a second edge at an end away from the first main body part. The first main body part and the first thinning part are each provided with a first through hole, and two third terminal parts are respectively arranged in the two first through holes and connected to the first main body part and the first thinning part. 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.

[0030] The two third terminal parts are approximately symmetrically arranged in the thickness direction, which can improve the stability of the first terminal part and the structural strength of the first electrode terminal.

[0031] In some embodiments, a cross section of the third terminal part perpendicular to the thickness direction of the first wall part is circular, elliptical or track-shaped.

[0032] In some embodiments, the first tab is welded to the second terminal part and forms a first welding mark. Directly welding the first tab to the second terminal part can shorten the conductive path between the first tab and the second terminal part, reduce the resistance, and reduce the heat generation of the first tab and the second terminal part.

[0033] In some embodiments, the first thinning part is used for heat exchange with a heat exchange member of the battery. The first welding mark is configured to at least partially overlap with the heat exchange member in the thickness direction of the first wall part. When current passes through the first welding mark, the first welding mark generates heat. 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.

[0034] In some embodiments, in the thickness direction of the first wall part, the projection area of the first terminal part is greater than the projection area of the second terminal part. The first terminal part can have a larger area than the second terminal part, which can improve the heat dissipation efficiency of the first terminal part; under the premise that the overcurrent area meets the requirements, the second terminal part can have an area smaller than that of the first terminal part, thereby saving the internal space of the shell and improving the energy density of the battery monomer.

[0035] In some embodiments, in the thickness direction of the first wall part, the projection area of the second terminal part is 0.2-0.5 times the projection area of the first wall part.

[0036] The ratio of the projection area of the second terminal portion to the projection 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 a larger flow area, thereby reducing the resistance, reducing the heat generation of the second terminal portion and the heat generation of the first tab, and reducing the temperature rise of the battery cell. The ratio of the projection area of the second terminal portion to the projection area of the first wall portion is less than or equal to 0.5, which can reserve installation space for other components inside 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 cell.

[0037] In some embodiments, in the thickness direction of the first wall portion, the projection area of the first terminal portion is 0.2-0.5 times the projection area of the first wall portion.

[0038] The ratio of the projection area of the first terminal portion to the projection area of the first wall portion is greater than or equal to 0.2, and the first terminal portion has a larger exposed area, thereby improving the heat exchange efficiency and improving the cycle performance and reliability of the battery cell. The ratio of the projection area of the first terminal portion to the projection 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 cell.

[0039] In some embodiments, the first main body portion is configured to be connected with the first current collecting component of the battery, and the first thinning portion is configured to exchange heat with the heat exchange member of the battery.

[0040] In the cycle process of the battery, current flows through the first current collecting component and the first terminal portion, causing the first terminal portion and the first current collecting component to generate heat. The first thinning 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 with the first tab, and the heat of the first tab can also be conducted to the heat exchange member through the first thinning portion, thereby reducing the temperature rise of the electrode assembly and improving the cycle performance and cycle life of the battery cell.

[0041] In some embodiments, the first main body portion is configured to at least partially overlap and connect with the first current collecting component in the thickness direction of the first wall portion, and the first thinning portion is configured to at least partially overlap with the heat exchange member in the thickness direction.

[0042] The first main body portion and the first current collecting component are arranged in the thickness direction, which can increase the connection strength and flow area between the first main body portion and the first current collecting component, and reduce heat generation. The first thinning portion and the heat exchange member are arranged in the thickness direction, which can increase the heat exchange area of the first thinning portion and the heat exchange member, and improve the heat exchange efficiency. The first current collecting component and the heat exchange member can share space in the thickness direction, thereby improving the space utilization in the thickness direction and improving the energy density of the battery.

[0043] 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.

[0044] In some embodiments, the surface of the first main body portion away from the first wall portion includes a first region, and the surface of the first thinning portion away from the first wall portion includes a second region. The first region is configured to overlap and connect with the first busbar component in the thickness direction of the first wall portion, and the second region is configured to overlap with the heat exchange member in the thickness direction.

[0045] The first busbar component and the heat exchange member respectively act on the first region and the second region, which can reduce the risk of interference between the first busbar component and the heat exchange member, and reduce the superposition of the first busbar component and the heat exchange member in the thickness direction, thereby improving the space utilization.

[0046] In some embodiments, the first region is spaced apart from the second region to reduce the risk of interference between the first busbar component and the heat exchange member due to assembly errors.

[0047] 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 thinning portion, reduce the temperature rise of the first terminal portion, and improve the cycle performance and reliability of the battery cell.

[0048] In some embodiments, the ratio of the area of the first region to the projected area of the first terminal portion in the thickness direction is greater than or equal to 1.5%, so that the first main body portion and the first busbar component have a larger connection area and a higher connection strength, thereby improving the flow capacity between the first main body portion and the first busbar component, reducing heat generation, and reducing temperature rise.

[0049] In some embodiments, the ratio of the area of the second region to the projected area of the first terminal portion in the thickness direction is greater than or equal to 10%, so that the first thinning portion and the heat exchange member have a larger heat exchange area, thereby improving the heat exchange efficiency between the first thinning portion and the heat exchange member, reducing the temperature rise of the first thinning portion and the electrode assembly, and improving the cycle performance of the battery cell.

[0050] In some embodiments, the electrode assembly further includes a second tab, and the first tab and the second tab are opposite in polarity. The battery cell further includes a second electrode terminal disposed on the shell, and the second electrode terminal is electrically connected to the second tab.

[0051] In some embodiments, the second electrode terminal includes a fourth terminal portion located on the outside of the shell, and the fourth terminal portion includes a second main body portion and a second thinning portion, and the thickness of the second main body portion is greater than the thickness of the second thinning portion.

[0052] The second main body part has a larger thickness than the second thinning part, and is not easy to be melted when welded with other components, thereby improving the reliability of the battery cell. For example, the second main body part can be used for welding with the second current collecting component. Since the second main body part has a larger thickness, the welding strength can be increased, the overcurrent capacity can be improved, and the heat generation can be reduced. By arranging the second thinning part, the exposed area of the second electrode terminal can be increased, thereby improving the heat dissipation capacity of the battery cell, reducing the temperature rise in the battery cell, and improving the cycle performance of the battery cell. The second thinning part has a smaller thickness, thereby reducing the influence of the second thinning part on the energy density of the battery cell.

[0053] In some embodiments, the second main body part is used for connecting with the second current collecting component of the battery, and the second thinning part is used for heat exchange with the heat exchange member of the battery.

[0054] In the cycle process of the battery, the current flows through the second current collecting component and the fourth terminal part, causing the fourth terminal part and the second current collecting component to generate heat. The second thinning part 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 in the rapid charging process. The second electrode terminal is connected with the second tab, and the heat of the second tab can also be conducted to the heat exchange member through the second thinning part, thereby reducing the temperature rise of the electrode assembly and improving the cycle performance and cycle life of the battery cell.

[0055] In some embodiments, the second electrode terminal is arranged on the first wall part. The first thinning part, the first main body part, the second main body part, and the second thinning part are arranged along a first direction, and the first direction is perpendicular to the thickness direction; or the first main body part, the first thinning part, the second thinning part, and the second main body part are arranged along the first direction. The embodiments of the present application are helpful for arranging a plurality of battery cells into a group.

[0056] In some embodiments, the second electrode terminal includes a fourth terminal part located on the outside of the shell. The projection area of the first terminal part along the thickness direction thereof is greater than the projection area of the fourth terminal part along the thickness direction thereof.

[0057] Arranging the first terminal part including the first thinning part to be larger can increase the heat dissipation area and improve the heat exchange efficiency. The fourth terminal part can have a smaller area, thereby saving space and improving the energy density of the battery cell. The first thinning part has a smaller thickness, and the influence of the first thinning part on the energy density of the battery cell is smaller.

[0058] In some embodiments, the projection area of the first terminal part along the thickness direction thereof is 1.2-5 times the projection area of the fourth terminal part along the thickness direction thereof, and optionally, the projection area of the first terminal part along the thickness direction thereof is 2-3 times the projection area of the fourth terminal part along the thickness direction thereof.

[0059] The embodiments of the present application can balance the heat dissipation area of the first terminal part, the overcurrent capacity of the first terminal part and the overcurrent capacity of the fourth terminal part to some extent, and improve the cycle performance of the battery monomer.

[0060] In some embodiments, the shell 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 part and a third terminal part, the second terminal part is located inside the first wall part and is electrically connected to the first tab, at least part of the third terminal part is accommodated in the first electrode lead-out hole, and the third terminal part connects the second terminal part and the first terminal part. The second electrode terminal further includes a fourth terminal part, a fifth terminal part and a sixth terminal part, the fourth terminal part is located outside the shell, the fifth terminal part is located inside the shell and is electrically connected to the second tab, at least part of the sixth terminal part is accommodated in the second electrode lead-out hole, and the sixth terminal part connects the fifth terminal part and the fourth terminal part. The projection area of the second terminal part in the thickness direction thereof is greater than the projection area of the fifth terminal part in the thickness direction thereof.

[0061] Compared with the fifth terminal part, the second terminal part can have a larger overcurrent area, thereby reducing the heat generation of the second terminal part. By setting the second terminal part to have a larger area, the strength difference between the first terminal part and the second terminal part can be reduced, the deformation of the second terminal part when the battery monomer is subjected to external impact can be reduced, and the stability of the fixation of the first electrode terminal and the first wall part can be improved.

[0062] In some embodiments, the projection area of the second terminal part in the thickness direction thereof is 1.2-5 times the projection area of the fifth terminal part in the thickness direction thereof, and optionally, the projection area of the second terminal part in the thickness direction thereof is 2-3 times the projection area of the fifth terminal part in the thickness direction thereof.

[0063] The embodiments of the present application can balance the overcurrent capacity of the first electrode terminal and the overcurrent capacity of the second electrode terminal to some extent, and improve the cycle performance of the battery monomer.

[0064] In some embodiments, the second electrode terminal is arranged on the first wall part, and the second electrode terminal includes a fourth terminal part located outside the first wall part. In the thickness direction of the first wall part, the projection area of the first terminal part is S1, the projection area of the fourth terminal part is S2, and the projection area of the first wall part is S3. S1, S2 and S3 satisfy: 0.2≤(S1+S2) / S3≤0.8; and optionally, 0.3≤(S1+S2) / S3≤0.5.

[0065] The (S1+S2) / S3 is greater than or equal to 0.2, the first terminal part and the fourth terminal part have a large exposed area as a whole, the heat dissipation capacity and the overcurrent capacity of the first electrode terminal and the heat dissipation capacity and the overcurrent capacity of the second electrode terminal are improved, and the cycle performance of the battery monomer is improved. The (S1+S2) / S3 is less than or equal to 0.8, the installation space of other components is reserved, the distance between the first terminal part and the second terminal part is maintained, and the short circuit risk is reduced.

[0066] 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.

[0067] The S1 / S3 is greater than or equal to 0.3, the first terminal part has a large area, the heat dissipation capacity and the overcurrent capacity of the first electrode terminal are improved, and the cycle performance of the battery monomer is improved. The S1 / S3 is less than or equal to 0.8, the installation space of other components is reserved, and the influence of the first terminal part on the energy density of the battery monomer is reduced.

[0068] In some embodiments, the shell includes a second wall part, and the battery monomer includes a pressure relief mechanism arranged on the second wall part.

[0069] The pressure relief mechanism is arranged on the second wall part, more space is reserved on the first wall part for installing the first electrode terminal, the first terminal part can have 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 the cycle life of the battery monomer are improved.

[0070] 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.

[0071] In some embodiments, the first wall part is provided with an electrolyte injection hole. In the production process of the battery monomer, electrolyte can be injected into the shell through the electrolyte injection hole.

[0072] In some embodiments, the shell includes a shell body and an end cover, the shell body has an opening, and the end cover is connected to the shell body and covers the opening. The end cover is the first wall part.

[0073] Compared with the shell body, the end cover usually has a larger thickness; the first electrode terminal is arranged on the end cover, the connection strength between the first electrode terminal and the end cover is improved, the stability of the first electrode terminal is improved, and the risk of the first electrode terminal deviating is reduced.

[0074] In the second aspect, the embodiments of the present application provide a battery, which comprises the battery cell, the first bus component and the heat exchange component according to any one of the embodiments of the first aspect. The first bus component is connected to the first main body. At least part of the heat exchange component is located on the side of the first wall away from the electrode assembly and exchanges heat with the first thinning portion.

[0075] In some embodiments, in the thickness direction of the first wall, at least part of the first thinning portion is located between the heat exchange component and the first wall. The heat exchange component can exchange heat with the first thinning portion, thereby improving the heat dissipation efficiency of the battery cell and improving the cycle performance of the battery cell.

[0076] In some embodiments, the battery further comprises a box. The battery cell and the first bus component are accommodated in the box, and the heat exchange component is arranged outside the box. The embodiments of the present application can save the internal space of the box and improve the space utilization.

[0077] In the third aspect, the embodiments of the present application provide a power utilization device, which comprises the battery according to any one of the embodiments of the second aspect, and the battery is used to provide electric energy. BRIEF DESCRIPTION OF DRAWINGS

[0078] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments of the present application will be briefly introduced as follows. 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.

[0079] FIG. 1 is a structural schematic diagram of a vehicle according to some embodiments of the present application;

[0080] FIG. 2 is a schematic diagram of a battery according to some embodiments of the present application;

[0081] FIG. 3 is a schematic diagram of part of the structure of a battery according to some embodiments of the present application;

[0082] FIG. 4 is a partial cross-sectional schematic diagram of a battery according to some embodiments of the present application;

[0083] FIG. 5 is a structural schematic diagram of a battery according to some embodiments of the present application;

[0084] FIG. 6 is an exploded schematic diagram of the battery cell shown in FIG. 5;

[0085] FIG. 7 is an enlarged schematic diagram of the part A of FIG. 4;

[0086] FIG. 8 is an enlarged schematic diagram of the part B of FIG. 4;

[0087] FIG. 9 is a structural schematic diagram of an end cover assembly of a battery cell according to some embodiments of the present application;

[0088] Fig. 10 is a top view of the end cap assembly shown in Fig. 9;

[0089] Fig. 11 is a bottom view of the end cap assembly shown in Fig. 9;

[0090] Fig. 12 is a structural schematic of an end cap assembly according to some embodiments of the application;

[0091] Fig. 13 is a structural schematic of an end cap assembly of a battery cell according to some embodiments of the application;

[0092] Fig. 14 is a structural schematic of an end cap assembly of a battery cell according to some embodiments of the application;

[0093] Fig. 15 is a top view of the end cap assembly shown in Fig. 14;

[0094] Fig. 16 is a structural schematic of an end cap assembly of a battery cell according to some embodiments of the application;

[0095] Fig. 17 is a simplified schematic of a battery cell according to some embodiments of the application;

[0096] Fig. 18 is a cross-sectional schematic of a battery according to some embodiments of the application.

[0097] In the drawings, the drawings are not drawn to scale.

[0098] Explanation of Reference Numerals: 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; 10, electrode assembly; 11, electrode main body; 12, first tab; 13, second tab; 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; 30, first electrode terminal; 31, first terminal portion; 311, first main portion; 312, first thinning portion; 313, first recessed portion; 314, first through-hole; 31a, first region; 31b, second region; 31c, first edge; 31d, second edge; 32, second terminal portion; 33, third terminal portion; 40, second electrode terminal; 41, fourth terminal portion; 411, second main portion; 412, second thinning portion; 413, second recessed portion; 414, second through-hole; 41e, first plate; 41f, second plate; 42, fifth terminal portion; 43, sixth terminal portion; 50, end cover assembly; 60, pressure relief mechanism; 70, sealing sheet; 80a, first solder print; 80b, second solder print; X, first direction; Y, second direction; Z, thickness direction. DETAILED DESCRIPTION

[0099] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of the present application.

[0100] 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 of the present application is only for the purpose of describing specific embodiments and is not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification of the present application and claims and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification of the present application and claims or the above description of drawings are used to distinguish different objects, not to describe a particular order or primary and secondary relationship.

[0101] The phrase "in an embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily mutually exclusive of one another.

[0102] In the description of the application, it is necessary to point out that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "attachment" should be understood broadly, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be directly connected, can also be indirectly connected through an intermediate medium, 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.

[0103] The term "and / or" in this application is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can mean that A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this application generally represents that the front and rear associated objects have an "or" relationship.

[0104] 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, width and other dimensions of various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device, are only exemplary and should not constitute any limitation on the application.

[0105] "Ranges" disclosed herein are defined, for each specific range of values, by a lower limit and an upper limit, defining a particular range. Ranges can either be inclusive or exclusive of the end values, and are arbitrarily combinable, i.e., any lower limit can be combined with any upper limit to define a range. For example, if a range of 60 to 120 and a range of 80 to 110 are listed for a particular parameter, 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 any integers between a and b, in which a and b are real numbers. For example, the numerical range "0 to 5" indicates that all real numbers between "0 to 5" have been listed herein, "0 to 5" is merely a shorthand for listing all of these numerical combinations. Also, 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.

[0106] "Plural" as used herein means two or more (including two).

[0107] Currently, 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.

[0108] 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.

[0109] With the development of the battery, especially widely used in daily life, users hope that the battery can be charged 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 range during the entire charging process, affecting the cycle performance and cycle life of the battery, and aggravating the risk of thermal runaway of the battery.

[0110] In view of this, the battery cell provided in the embodiments of the present application has an electrode terminal including an exposed main body part and a thinned part, and the thickness of the thinned part is less than that of the main body part. The main body part can be used for welding with a busbar part, and the main body part has a larger thickness, which can reduce the risk of the main body part being melted through and improve the overcurrent capacity and reduce heat generation. By providing the thinned part, the exposed area of the electrode terminal can be increased, thereby improving the heat dissipation capacity of the battery cell, reducing the temperature rise inside the battery cell, and improving the cycle performance of the battery cell. The thinned part does not need to be welded with the busbar part, and the thinned part can have a smaller thickness, thereby reducing the impact of the added thinned part on the energy density of the battery cell.

[0111] The battery described in the embodiments of the present application is suitable for use in 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 car, a ship, a spacecraft, etc. Among them, the electric toy can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric plane toys, etc., and the spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0112] The following embodiments are described by taking a vehicle as an example for convenience of description.

[0113] FIG. 1 is a structural schematic diagram of a vehicle provided in some embodiments of the present application.

[0114] As shown in FIG. 1, a vehicle 1 is internally provided with a battery 2, which can be arranged at the bottom, head or 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.

[0115] The vehicle 1 can further include a controller 3 and a motor 4, and the controller 3 is used to control the battery 2 to supply power to the motor 4, for example, to meet the power demand of the vehicle 1 during starting, navigation and driving.

[0116] 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, to replace or partially replace fuel or natural gas to provide driving power for the vehicle 1.

[0117] FIG. 2 is a schematic diagram of a battery provided in some embodiments of the present application.

[0118] Referring to FIG. 2, in some embodiments, the battery 2 includes a box body 5 and a plurality of battery cells 6 contained in the box body 5.

[0119] The battery cell 6 can be a secondary battery cell, which refers to a battery cell 6 that can be used continuously by activating the active material through charging after the battery cell 6 is discharged.

[0120] By way of example, the battery cell 6 can be a lithium ion battery cell, a sodium ion battery cell, a sodium lithium ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium sulfur battery cell, a magnesium ion battery cell, a nickel hydrogen battery cell, a nickel cadmium battery cell, a lead-acid battery cell, or the like.

[0121] By way of 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, such as a hexagonal battery cell, or the like.

[0122] The plurality of battery cells 6 can be connected in series, in parallel, or in a mixed manner, the mixed manner referring to a manner in which the plurality of battery cells 6 are connected in series and in parallel. The plurality of battery cells 6 can be directly connected in series, in parallel, or in a mixed manner, and the plurality of battery cells 6 can be accommodated in the case 5 as a whole. 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 can be connected in series, in parallel, or in a mixed manner to form a whole, which can be accommodated in the case 5.

[0123] In some embodiments, the case 5 is configured to accommodate the battery cell 6, and the case 5 can have various structures.

[0124] In some embodiments, the case 5 can include a first case portion 5a and a second case portion 5b, the first case portion 5a and the second case portion 5b being coupled to each other to define an accommodation space for accommodating the battery cell 6. The second case portion 5b can be a hollow structure having an open end, and the first case portion 5a can be a plate-shaped structure, the first case portion 5a being coupled to the open end of the second case portion 5b to form the case 5 having the accommodation space. Alternatively, the first case portion 5a and the second case portion 5b can each be a hollow structure having an open end, and the open end of the first case portion 5a can be coupled to the open end of the second case portion 5b to form the case 5 having the accommodation space. Of course, the first case portion 5a and the second case portion 5b can have various shapes, such as a cylindrical shape, a cuboid shape, or the like.

[0125] To improve the sealing performance of the case 5 after the first case portion 5a and the second case portion 5b are coupled to each other, a sealing member, such as a sealant, a gasket, or the like, can be provided between the first case portion 5a and the second case portion 5b.

[0126] 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.

[0127] 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.

[0128] FIG. 3 is a schematic diagram of part of the structure of the battery according to some embodiments of the present application.

[0129] 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.

[0130] The plurality of busbar components 7 connect the plurality of battery cells 6 in series, in parallel, or in a hybrid manner.

[0131] The plurality of busbar components 7 can have the same structure or different structures.

[0132] The busbar component 7 can have a single-layer structure or a multi-layer structure.

[0133] 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 is connected to 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 is connected to the first electrode terminals 30 of two battery cells 6 to connect the two battery cells 6 in parallel.

[0134] In some embodiments, the busbar component 7 is welded to the first electrode terminal 30.

[0135] In some embodiments, the busbar component 7 has a multi-layer structure. For example, the busbar component 7 has a multi-layer structure in the thickness direction of the busbar component 7, such as a double-layer structure or a triple-layer structure formed by bending.

[0136] 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 generated by the busbar component 7 when an 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.

[0137] The busbar component 7 is provided as a multi-layer structure under the premise that the flow area meets the requirements, so that the thickness of each layer of the busbar component 7 can be reduced. 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. The layer of the busbar component 7 has a smaller thickness, which is easy 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.

[0138] In some embodiments, the battery 2 further comprises a heat exchange plate 8 for heat exchange with the shell of the battery cell 6.

[0139] The heat exchange plate 8 can exchange heat with the battery cell 6 during the cycle process of the battery cell 6, so that the battery cell 6 is kept within a suitable temperature range, improving the cycle performance and cycle life of the battery cell 6, and reducing the risk of thermal runaway.

[0140] In some embodiments, the shell has two oppositely arranged 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.

[0141] 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, improving 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.

[0142] In some embodiments, the battery cell 6 is provided with a heat exchange plate 8 on both sides, i.e., the two large faces of the battery cell 6 exchange heat with two heat exchange plates 8 respectively.

[0143] In some embodiments, the battery 2 comprises 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.

[0144] In some embodiments, the battery 2 further comprises a heat exchange member 9 for heat exchange with the electrode terminal of the battery cell 6.

[0145] The heat exchange member 9 can exchange heat with only the first electrode terminal 30, or only the second electrode terminal 40, or simultaneously with the first electrode terminal 30 and the second electrode terminal 40.

[0146] 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.

[0147] As an example, for two battery cells 6 arranged adjacently, the heat exchange member 9 can exchange heat with the first electrode terminals 30 of both battery cells 6, with the first electrode terminal 30 of one battery cell 6 and the second electrode terminal 40 of the other battery cell 6, or with the first electrode terminals 30 and the second electrode terminals 40 of both battery cells 6.

[0148] As an example, the heat exchange member 9 can exchange heat with the electrode terminals directly, or indirectly through other heat conductive members.

[0149] As an 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 terminals through the box 5.

[0150] In some embodiments, the heat exchange member 9 comprises a heat exchange pipe. As an example, the heat exchange pipe is a flat pipe.

[0151] 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 terminals through the heat exchange member 9.

[0152] 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 in FIG. 4; FIG. 8 is an enlarged schematic view of a portion B in 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.

[0153] Referring to FIGS. 4-11, in some embodiments, the battery cell 6 comprises a housing 20 and an electrode assembly 10, at least a portion of the electrode assembly 10 being accommodated in the housing 20.

[0154] The housing 20 is a hollow structure, and an accommodation space for accommodating the electrode assembly 10 and electrolyte is formed inside 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.

[0155] In some embodiments, the housing 20 comprises a shell 21 and an end cover 22, the shell 21 having an opening, and the end cover 22 being connected to the shell 21 and covering the opening.

[0156] 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.

[0157] The shell 21 and the end cover 22 can be separate components. In some examples, the shell 21 can be provided with an opening, and the end cover 22 can be configured to cover the opening to form an internal cavity of the battery cell 6.

[0158] The shell 21 can be in various shapes and sizes, such as a cuboid, a cylinder, a hexagonal prism, etc. In particular, 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 present application does not make special limitations on this.

[0159] The end cover 22 can be in a shape that is 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. Alternatively, 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 cell 6 can have higher structural strength and improved reliability.

[0160] The end cover 22 can be connected to the shell 21 by welding, bonding, clamping, or other means.

[0161] The shell 21 can be open at one end or both ends. In some examples, the shell 21 can be open at one side, and the end cover 22 can be provided as one and cover the shell 21. In other examples, the shell 21 can be open at both ends, and the end cover 22 can be provided as two and cover the two openings of the shell 21.

[0162] The electrode assembly 10 is a component in which electrochemical reactions occur in the battery cell 6. The shell 21 can contain one or more electrode assemblies 10.

[0163] In some embodiments, the electrode assembly 10 includes a positive electrode sheet and a negative electrode sheet. During charging and discharging of the battery cell 6, active ions (such as lithium ions) are inserted and extracted between the positive electrode sheet and the negative electrode sheet.

[0164] 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 short circuiting of the positive and negative electrodes and allow the active ions to pass through.

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

[0166] As an example, the positive electrode tab has two surfaces opposite in the thickness direction thereof, and the positive electrode film layer is provided on either one or both of the two surfaces of the positive electrode tab.

[0167] In some embodiments, the negative electrode tab can include a negative electrode current collector and a negative electrode film layer provided on at least one surface of the negative electrode current collector. As an example, a portion of the negative electrode current collector on which the negative electrode film layer is not provided can serve as a negative electrode tab.

[0168] In some embodiments, the electrode assembly 10 includes an electrode body 11, a first electrode tab 12, and a second electrode tab 13, the first electrode tab 12 and the second electrode tab 13 being drawn from the electrode body 11. The first electrode tab 12 and the second electrode tab 13 are opposite in polarity, in other words, one of the first electrode tab 12 and the second electrode tab 13 is a positive electrode tab, and the other is a negative electrode tab.

[0169] As an example, the positive electrode tab has a portion of the positive electrode current collector coated with the positive electrode film layer, a portion of the negative electrode current collector coated with the negative electrode film layer, the positive electrode film layer, the negative electrode film layer, and the separator film constitute the electrode body 11. The positive electrode tab and the negative electrode tab can be drawn from the same end of the electrode body 11, or can be drawn from both ends of the electrode body 11, respectively.

[0170] In some embodiments, the electrode assembly 10 is in a jelly-roll structure. The positive electrode tab and the negative electrode tab are wound into the jelly-roll structure.

[0171] In some embodiments, the electrode assembly 10 is in a stack structure.

[0172] As an example, a plurality of positive electrode tabs and a plurality of negative electrode tabs can be provided, and the plurality of positive electrode tabs and the plurality of negative electrode tabs can be alternately stacked.

[0173] As an example, a plurality of positive electrode tabs can be provided, and the negative electrode tab can be folded to form a plurality of folded sections stacked one on another, and one positive electrode tab can be interposed between adjacent folded sections.

[0174] As an example, both the positive electrode tab and the negative electrode tab can be folded to form a plurality of folded sections stacked one on another.

[0175] As an example, a plurality of separators can be provided, and each of the plurality of separators can be interposed between any adjacent positive electrode tab or negative electrode tab.

[0176] As an example, the separators can be continuously provided, and can be interposed between any adjacent positive electrode tab or negative electrode tab by being folded or wound.

[0177] In some embodiments, the battery cell 6 includes a first electrode terminal 30 and a second electrode terminal 40 insulated from each other, the first electrode terminal 30 being electrically connected to the first electrode tab 12, and the second electrode terminal 40 being electrically connected to the second electrode tab 13.

[0178] The first electrode terminal 30 and the second electrode terminal 40 are configured to be electrically connected to an external circuit to enable charging or discharging of the battery cell 6.

[0179] As an example, the first electrode terminal 30 can be a separately formed component that is mounted to the housing 20. Alternatively, the first electrode terminal 30 can also be formed as part of the housing 20.

[0180] 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.

[0181] 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 before being assembled with the electrode assembly 10 and the casing 21.

[0182] 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.

[0183] 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, it can cause thermal runaway inside the battery cell 6 and thus a sudden increase in pressure. In this case, the internal pressure can be released outwardly by actuating the pressure relief mechanism 60 to reduce the risk of explosion or fire of the battery cell 6.

[0184] 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 depending on the design requirements. The threshold can depend on the material of one or more of the positive plate, the negative plate, the electrolyte and the separator in the battery cell 6.

[0185] 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.

[0186] When the battery cell 6 is in thermal runaway, the discharge of the battery cell 6 includes, but is not limited to, electrolyte, positive and negative electrode sheets dissolved or split, fragments of the separator, high-temperature and high-pressure gas generated by the reaction, flame, and the like.

[0187] In some embodiments, the pressure relief mechanism 60 is disposed on the housing 20. Exemplarily, the pressure relief mechanism 60 can be disposed on the shell 21 or the end cover 22.

[0188] In some embodiments, the battery cell 6 provided by the embodiments of the present application includes a housing 20, an electrode assembly 10, and a first electrode terminal 30. The housing 20 includes a first wall portion 20a. The electrode assembly 10 is accommodated in the housing 20, and the electrode assembly 10 includes a first tab 12. The first electrode terminal 30 is disposed on the first wall portion 20a and electrically connected to the first tab 12. The first electrode terminal 30 includes a first terminal portion 31 located outside the first wall portion 20a. The first terminal portion 31 includes a first main body portion 311 and a first thinned portion 312, and the thickness t1 of the first main body portion 311 is greater than the thickness t2 of the first thinned portion 312.

[0189] The first wall portion 20a can be the end cover 22 or a wall of the shell 21.

[0190] 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.

[0191] 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.

[0192] The first electrode terminal 30 can be one or multiple.

[0193] Exemplarily, 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.

[0194] In the first direction X, the size of the first main body portion 311 can be the same as or different from the size of the first thinned portion 312. In the second direction Y, the size of the first main body portion 311 can be the same as or different from the size of the first thinned portion 312. Exemplarily, the first direction X, the second direction Y, and the thickness direction Z of the first wall portion 20a are perpendicular to each other. Exemplarily, 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.

[0195] The first main body portion 311 and the first thinned portion 312 can be connected or separated.

[0196] Exemplarily, in the thickness direction Z of the first wall portion 20a, the first main body portion 311 can be flush with the surface of the first wall portion 20a or can not be flush with the surface of the first wall portion 20a.

[0197] In the embodiments of the present application, the first main body portion 311 has a greater thickness than the first thinning portion 312, and is not easy to be melted when welded with other components, thereby improving the reliability of the battery cell. Exemplarily, the first main body portion 311 can be used for welding with the first current collecting component. Since the first main body portion 311 has a greater thickness, the welding strength can be increased, the overcurrent capacity can be improved, and the heat generation can be reduced. By providing the first thinning portion 312, the exposed area of the first electrode terminal 30 can be increased, thereby improving the heat dissipation capacity of the battery cell 6, reducing the temperature rise inside the battery cell 6, and improving the cycle performance of the battery cell 6. The first thinning portion 312 has a smaller thickness, thereby reducing the influence of the first thinning portion 312 on the energy density of the battery cell 6.

[0198] In some embodiments, the first main body portion 311 is used for connecting with the first current collecting component 7a of the battery. As an example, the first current collecting component 7a is welded with the first main body portion 311; optionally, the first current collecting component 7a is laser welded with the first main body portion 311. The first main body portion 311 has a greater thickness, which is not easy to be melted when welded.

[0199] In some embodiments, the first thinning portion 312 is used for heat exchange with the heat exchange member 9 of the battery.

[0200] The first thinning portion 312 can be in contact with the heat exchange member 9 for heat exchange, or can indirectly exchange heat with the heat exchange member through other heat conduction structures.

[0201] In the cycle process of the battery 2, the current flows through the first current collecting component 7a and the first terminal portion 31, causing the first terminal portion 31 and the first current collecting component 7a to generate heat. The first thinning portion 312 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 with 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 thinning portion 312, thereby reducing the temperature rise of the electrode assembly 10 and improving the cycle performance and cycle life of the battery cell 6.

[0202] The first main body portion 311 and the first thinning portion 312 can respectively play the roles of transmitting current and dissipating heat.

[0203] The first current collecting component 7a and the heat exchange member 9 act on different parts of the first terminal portion 31, which can reduce the risk of interference between the first current collecting component 7a and the heat exchange member 9.

[0204] In some embodiments, the first main body portion 311 has a thickness greater than or equal to 3 mm.

[0205] In some embodiments, the ratio of the thickness of the first main body portion 311 to the first thinning portion 312 is 1.2-3. Optionally, t1 / t2 is 1.2, 1.5, 2, 2.5, or 3.

[0206] In some embodiments, the first main body portion 311 extends beyond the first thinning portion 312 in a direction away from the first wall portion 20a.

[0207] In the thickness direction Z of the first wall portion 20a, the surface of the first thinning portion 312 away from the first wall portion 20a is closer to the first wall portion 20a than the surface of the first thinning portion 312 away from the first wall portion 20a, thereby reserving more space on the side of the first thinning portion 312 away from the first wall portion 20a to facilitate the arrangement of other components (e.g., the heat exchange member 9), and improving the space utilization.

[0208] 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 first thinning portion 312 is the bottom wall of the first recess 313.

[0209] By providing the first recess 313, space can be provided for other components of the battery (e.g., the heat exchange member 9), and the space utilization in the thickness direction Z of the first wall portion 20a is improved.

[0210] In some embodiments, the first recess 313 is located on one side of the first main body portion 311 along the first direction X. The end of the first recess 313 away from the first main body portion 311 along 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 main body portion 311 along 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 thickened portion (not shown) having a thickness greater than that of the first thinning portion 312, the first thinning portion 312 being connected between the first main body portion 311 and the thickened portion, and the first recess 313 being located between the first main body portion 311 and the thickened portion along the first direction X.

[0211] In some embodiments, along the second direction Y, the first recess 313 extends through the first terminal portion 31.

[0212] In some embodiments, in the thickness direction Z of the first wall portion 20a, the depth h of the first recess 313 is 0.1-2 mm.

[0213] As an example, h is 0.1 mm, 0.2 mm, 0.3 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.8 mm, or 2.0 mm.

[0214] Limiting the depth of the first recess 313 to be greater than or equal to 0.1 mm can provide more space for other components (e.g., the heat exchange member 9), improving space utilization. Limiting the depth of the first recess 313 to be less than or equal to 2 mm can reduce the risk of deformation of the first thinned portion 312 when the battery cell 6 is subjected to external impact, improving the reliability of the battery cell 6.

[0215] In addition, limiting the depth of the first recess 313 to be less than or equal to 2 mm can also reduce the loss of thermal conductivity due to thinning of the first thinned portion 312, to some extent, taking into account the heat exchange efficiency of the first thinned portion 312 and the heat exchange member 9.

[0216] In some embodiments, the area of the first thinned portion 312 is greater than the area of the first main portion 311 as viewed in the thickness direction Z, which can make the heat exchange area between the first terminal portion 31 and the heat exchange member 9 larger.

[0217] In some embodiments, the first main portion 311 and the first thinned portion 312 are disposed along a first direction X, which is perpendicular to the thickness direction Z of the first wall portion 20a. In the first direction X, the size L22 of the first thinned portion 312 is greater than the size L21 of the first main portion 311.

[0218] The first thinned portion 312 has a size greater than the first main portion 311 in the first direction X, which can have a larger exposed area, thereby improving the heat dissipation efficiency, reducing the temperature rise inside the battery cell 6, and improving the cycle performance of the battery cell 6. The thickness of the first thinned portion 312 is less than the thickness of the first main portion 311, and increasing the size of the first thinned portion 312 in the first direction X has less impact on the volume and weight of the battery cell 6 than increasing the size of the first main portion 311 in the first direction X.

[0219] In addition, by increasing the size of the first thinned portion 312 in the first direction X, the heat exchange area between the first thinned portion 312 and the heat exchange member 9 can also be increased, improving the heat exchange efficiency.

[0220] In some embodiments, the distance between the heat exchange member 9 and the first thinned portion 312 in the thickness direction Z of the first wall portion 20a is less than the distance between the heat exchange plate 8 and the first thinned portion 312.

[0221] In some embodiments, the heat exchange plate 8 does not overlap the first electrode terminal 30 in the thickness direction Z of the first wall portion 20a.

[0222] 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.

[0223] 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.

[0224] 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.

[0225] 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.

[0226] 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.

[0227] 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.

[0228] 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.

[0229] 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.

[0230] 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.

[0231] The second electrode terminal 40 can be directly connected to the second tab 13, or indirectly connected to the second tab 13 through other conductive structures.

[0232] 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.

[0233] 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.

[0234] Directly connecting the second electrode terminal 40 to the second tab 13 can save a conventional jumper and can shorten the conductive path, reduce the resistance, and reduce the heat generation.

[0235] In some embodiments, the second electrode terminal 40 can be used to connect the second busbar component 7b of the battery.

[0236] 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.

[0237] As an example, two adjacent battery cells 6 are connected in series by one 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.

[0238] 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. 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.

[0239] 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.

[0240] 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.

[0241] As an example, the second wall portion 20b is the bottom wall of the shell 21.

[0242] 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.

[0243] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the material of the first electrode terminal 30 includes aluminum.

[0244] Exemplarily, the material of the first electrode terminal 30 is aluminum or an aluminum alloy.

[0245] 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.

[0246] In addition, by using aluminum for the first electrode terminal 30, the heat exchange efficiency between the first electrode terminal 30 and the heat exchange member 9 can be improved.

[0247] 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 providing the first thinning portion 312, the exposed area of the first electrode terminal 30 can be increased, 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.

[0248] Exemplarily, the heat exchange member 9 exchanges heat with the first thinning portion 312, which can further improve the efficiency of heat dissipation of the first tab 12 to the outside and reduce the temperature difference between the first tab 12 and the second tab 13.

[0249] In some embodiments, the projection of the first terminal portion 31 along the thickness direction Z is generally rectangular.

[0250] In some embodiments, the first main body portion 311 is configured to at least partially overlap and connect with the first busbar member 7a in the thickness direction Z of the first wall portion 20a. The first thinning portion 312 is configured to at least partially overlap with the heat exchange member 9 in the thickness direction Z.

[0251] The arrangement of the first main body portion 311 and the first busbar member 7a in the thickness direction Z can increase the connection strength and the flow area between the first main body portion 311 and the first busbar member 7a, and reduce heat generation. The arrangement of the first thinning portion 312 and the heat exchange member 9 in the thickness direction Z can increase the heat exchange area between the first thinning portion 312 and the heat exchange member 9, and improve the heat exchange efficiency. The first busbar 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.

[0252] In some embodiments, the first busbar member 7a is disposed on the first body portion 311 on a side away from the first wall portion 20a and is connected to the first body portion 311.

[0253] In some embodiments, the heat exchange member 9 is disposed on the first thinned portion 312 on a side away from the first wall portion 20a.

[0254] In some embodiments, the surface of the first terminal portion 31 on a side away from the first wall portion 20a is configured to be connected to the heat exchange member 9.

[0255] As an example, the surface of the first terminal portion 31 on a side away from the first wall portion 20a can be a flat surface or a stepped surface.

[0256] The surface of the first terminal portion 31 on a side away from the first wall portion 20a can be in direct contact with the heat exchange member 9 or can be indirectly connected to the heat exchange member 9 through other components. For example, the surface of the first terminal portion 31 on a side away from the first wall portion 20a can be thermally bonded to the heat exchange member 9.

[0257] In some embodiments, the surface of the first body portion 311 on a side away from the first wall portion 20a includes a first region 31a, and the surface of the first thinned portion 312 on a side away from the first wall portion 20a includes a second region 31b. The first region 31a is configured to overlap and be connected to the first busbar member 7a in the thickness direction Z of the first wall portion 20a, and the second region 31b is configured to overlap the heat exchange member 9 in the thickness direction Z.

[0258] As an example, the first region 31a is disposed in abutment with the first busbar member 7a.

[0259] 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.

[0260] The first region 31a and the second region 31b can be flush or can be misaligned in the thickness direction Z of the first wall portion 20a.

[0261] As an example, in FIG. 10, the first region 31a and the second region 31b are shown by diagonal lines.

[0262] The first region 31a and the second region 31b can be directly connected or can be spaced apart.

[0263] The first busbar member 7a and the heat exchange member 9 act on the first region 31a and the second region 31b, respectively, which can reduce the risk of interference between the first busbar member 7a and the heat exchange member 9 and reduce the overlap of the first busbar member 7a and the heat exchange member 9 in the thickness direction Z, thereby improving space utilization.

[0264] 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.

[0265] In some embodiments, the second region 31b has an area greater than that 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 thinned portion 312, reduce the temperature rise of the first terminal portion 31, and improve the cycle performance and reliability of the battery cell 6.

[0266] 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 greater than or equal to 1.5%, so that the first main body portion 311 and the first busbar component 7a have a larger connection area and higher connection strength, improving the current-carrying capacity between the first main body portion 311 and the first busbar component 7a, reducing heat generation, and reducing temperature rise.

[0267] For example, 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 1.5%, 2%, 3%, 5%, 8%, 10%, 15%, 20%, 25%, or 30%.

[0268] 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 2 . The first main body portion 311 and the first busbar component 7a have a larger connection area and higher connection strength, improving the current-carrying capacity between the first main body portion 311 and the first busbar component 7a, reducing heat generation, and reducing temperature rise.

[0269] 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 thinned portion 312 and the heat exchange member 9 have a larger heat exchange area, improving the heat exchange efficiency between the first thinned portion 312 and the heat exchange member 9, reducing the temperature rise of the first thinned portion 312 and the temperature rise of the electrode assembly 10, and improving the cycle performance of the battery cell 6.

[0270] As an example, the ratio of the area of the second region 31b to the projected area of the first terminal portion 31 in the thickness direction Z is 10%, 12%, 14%, 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%.

[0271] 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 less than or equal to 70%, and optionally less than or equal to 40%.

[0272] In some embodiments, the first wall portion 20a is provided with a first electrode lead-out hole 221.

[0273] As an example, the first electrode lead-out hole 221 penetrates the first wall portion 20a in the thickness direction Z of the first wall portion 20a.

[0274] The first electrode lead-out hole 221 can be one or multiple.

[0275] 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.

[0276] The first electrode lead-out hole 221 is provided to facilitate electrical connection between the first terminal portion 31 and the first tab 12.

[0277] In some embodiments, the first electrode terminal 30 further includes a second terminal portion 32 and a third terminal portion 33 connected to the second terminal portion 32, the second terminal portion 32 is located inside the first wall portion 20a and is 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 at least one of the first main body portion 311 and the first thinned portion 312 is connected to the third terminal portion 33. In the thickness direction Z of the first wall portion 20a, a portion of the first wall portion 20a is located between the first terminal portion 31 and the second terminal portion 32.

[0278] The third terminal portion 33 and the first terminal portion 31 can be an integrally formed structure. Alternatively, the third terminal portion 33 and the first terminal portion 31 can also be independently formed and fixedly connected by welding, clamping, bonding, or other means.

[0279] The third terminal portion 33 and the second terminal portion 32 can be an integrally formed structure. Alternatively, the third terminal portion 33 and the second terminal portion 32 can also be independently formed and fixedly connected by welding, clamping, bonding, or other means.

[0280] The third terminal portion 33 can be one or multiple.

[0281] The third terminal portion 33 and the first terminal portion 31 can be of the same material or different materials.

[0282] 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 also be connected to the first tab 12 through other conductive structures (for example, a jumper).

[0283] 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.

[0284] In some embodiments, the second terminal portion 32 and the third terminal portion 33 are integrally formed structures, 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.

[0285] Exemplarily, the third terminal portion 33 protrudes from the surface of the second terminal portion 32 facing the first wall portion 20a.

[0286] In some embodiments, at least one of the first main portion 311 and the first thinning portion 312 is provided with a first through hole 314, which penetrates 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.

[0287] 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.

[0288] In the thickness direction Z, the end of the third terminal portion 33 away from the second terminal portion 32 can or can not exceed the first through hole 314.

[0289] 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.

[0290] 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 heat exchange member 9.

[0291] During 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 providing the first through hole 314, the assembly process can be simplified.

[0292] In some embodiments, the first terminal portion 31 and the second terminal portion 32 are both flat plates. The third terminal portion 33 is columnar.

[0293] In some embodiments, the third terminal portion 33 is riveted to the first terminal portion 31.

[0294] In some embodiments, in the thickness direction Z, the 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 and other components.

[0295] Exemplarily, the embodiments of the present application can reduce the risk of the third terminal portion 33 interfering with the connection of the first terminal portion 31 and the first busbar component 7a, or reduce the risk of the third terminal portion 33 interfering with the connection of the first terminal portion 31 and the heat exchange component 9.

[0296] In some embodiments, the first thinning portion 312 is used for heat exchange with the heat exchange component 9 of the battery. The at least one third terminal portion 33 is configured such that the third terminal portion 33 is connected to the first thinning portion 312 and at least partially overlaps the heat exchange component 9 in the thickness direction Z.

[0297] In the cycle process of the battery cell 6, the heat of the first tab 12 is conducted to the first thinning portion 312 through the second terminal portion 32 and the third terminal portion 33. Overlapping the third terminal portion 33 with the heat exchange component 9 in the thickness direction Z can shorten the heat conduction path between the third terminal portion 33 and the heat exchange component 9, and improve the heat exchange efficiency.

[0298] In some embodiments, the at least one third terminal portion 33 is directly connected to the first main body portion 311, which can shorten the conductive path between the first tab 12 and the first main body portion 311, reduce the resistance, and reduce the heat generation.

[0299] In some embodiments, the first electrode terminal 30 includes a plurality of third terminal portions 33 arranged at intervals. By arranging a plurality of third terminal portions 33, the overcurrent capacity can be improved, the heat generation can be reduced, and the structural strength of the first electrode terminal 30 can be improved, and the stability of the connection of the first electrode terminal 30 and the first wall portion 20a can be improved.

[0300] In some embodiments, the first main body portion 311 is connected to the second terminal portion 32 through the at least one third terminal portion 33, so as to shorten the conductive path between the first tab 12 and the first main body portion 311. The first thinning portion 312 is connected to the second terminal portion 32 through the at least one third terminal portion 33, so as to shorten the heat conduction path between the first tab 12 and the first thinning portion 312.

[0301] Connecting the first main body portion 311 and the third terminal portion 33 can improve the stability of the first main body portion 311. When the battery cell 6 is subjected to external impact, the third terminal portion 33 can limit the deformation of the first main body portion 311, thereby reducing the risk of connection failure of the first main body portion 311 and the first busbar component 7a.

[0302] The first thinning portion 312 is connected with the third terminal portion 33. When the battery cell 6 is subjected to external impact, the third terminal portion 33 can limit the deformation of the first thinning portion 312, thereby reducing the stability of the heat exchange interface between the first thinning portion 312 and the heat exchange member 9.

[0303] In some embodiments, the first electrode lead-out hole 221 is multiple, and the multiple first electrode lead-out holes 221 are arranged one-to-one with the multiple third terminal portions 33.

[0304] In some embodiments, the first main body portion 311 and the first thinning portion 312 are arranged along a first direction X, and the first direction X is parallel to the length direction of the first wall portion 20a. An end of the first main body portion 311 away from the first thinning portion 312 has a first edge 31c, and an end of the first thinning portion 312 away from the first main body portion 311 has a second edge 31d. The first main body portion 311 and the first thinning portion 312 are both provided with a first through hole 314, and the two third terminal portions 33 are respectively arranged in the two first through holes 314 and are respectively connected to the first main body portion 311 and the first thinning portion 312. In the first direction X, the distance between the first edge 31c and the axis of the first through hole 314 close to the first edge 31c is D1, the distance between the second edge 31d and the axis of the first through hole 314 close to the second edge 31d is D2, and the distance between the axes of the two first through holes 314 is D3.

[0305] In some embodiments, D1 / D2 is 0.9-1.1, and (D1+D2) / D3 is 0.9-1.1.

[0306] For example, D1 / D2 is 0.9, 0.95, 1, 1.05, or 1.1.

[0307] For example, (D1+D2) / D3 is 0.9, 0.95, 1, 1.05, or 1.1.

[0308] 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 improve the structural strength of the first electrode terminal 30.

[0309] In some embodiments, D1=D2, and optionally, D3=2xD1.

[0310] In some embodiments, the cross section of the third terminal portion 33 perpendicular to the thickness direction Z of the first wall portion 20a is circular, elliptical, or racetrack-shaped.

[0311] In some examples, the third terminal portion 33 has a circular cross section, and the first electrode lead-out hole 221 is a circular hole. The circular third terminal portion 33 is easy to process; the first electrode lead-out hole 221 can be sealed by a circular sealing ring, and the circular sealing ring has uniform deformation and good sealing effect.

[0312] In other examples, the third terminal portion 33 has a racetrack-shaped cross section, and the first electrode lead-out hole 221 is a racetrack-shaped hole. The racetrack-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 racetrack-shaped third terminal portion 33, the circular third terminal portion 33 is easier to process.

[0313] In still other examples, the third terminal portion 33 has an elliptical cross section.

[0314] In some embodiments, the first tab 12 is welded to the second terminal portion 32 and forms a first welding mark 80a.

[0315] Directly welding the first tab 12 to 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.

[0316] In some embodiments, the first tab 12 is connected to the second terminal portion 32 by laser welding or ultrasonic welding.

[0317] In some embodiments, the first thinning portion 312 is used for heat exchange with the heat exchange member 9 of the battery. 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.

[0318] When current passes through the first welding mark 80a, the first welding mark 80a generates heat. 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.

[0319] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the first terminal portion 31 is greater than the projected area of the second terminal portion 32.

[0320] 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 flow 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.

[0321] In some embodiments, the projected area S1 of the first terminal portion 31 in the thickness direction Z of the first wall portion 20a is 0.2-0.5 times the projected area S3 of the first wall portion 20a.

[0322] Optionally, S1 / S3 is 0.2, 0.3, 0.4 or 0.5.

[0323] 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 has a larger exposed area, thereby improving the heat exchange efficiency and improving the cycle performance and reliability of the battery cell 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, and installation space can be reserved for other components of the battery cell 6.

[0324] In addition, limiting S1 / S3 to 0.2-0.5 can reserve a larger area for heat exchange with the heat exchange member 9 and increase the heat exchange area between the heat exchange member 9 and the first thinning portion 312.

[0325] 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.

[0326] It is explained here that the rectangle does not require an absolute rectangle, for example, the four corners of the rectangle can be provided as rounded corners.

[0327] In some embodiments, the projected area of the second terminal portion 32 in the thickness direction Z of the first wall portion 20a is 0.2-0.5 times the projected area of the first wall portion 20a.

[0328] 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 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 cell 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, and installation space can be reserved for other components inside the housing 20, reducing the risk of interference and short circuit between the second terminal portion 32 and other components, and improving the reliability of the battery cell 6.

[0329] In some embodiments, the second electrode terminal 40 includes a fourth terminal portion 41 located on the outside of the housing 20. Exemplarily, the fourth terminal portion 41 can be used to connect with the second bus member 7b.

[0330] The second electrode terminal 40 can be disposed on the first wall portion 20a, the second wall portion 20b, or another wall portion of the housing 20.

[0331] Exemplarily, the fourth terminal portion 41 can be disposed close to the heat exchange member 9 to exchange heat with the heat exchange member 9; alternatively, the fourth terminal portion 41 can be disposed away from the heat exchange member 9 to reduce heat exchange with the heat exchange member 9.

[0332] 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.

[0333] In some embodiments, the projection area of the first terminal portion 31 along the thickness direction thereof is greater than the projection area of the fourth terminal portion 41 along the thickness direction thereof.

[0334] The thickness direction of the first terminal portion 31 can be parallel to the thickness direction Z of the first wall portion 20a.

[0335] The thickness direction of the fourth terminal portion 41 is related to the position of the second electrode terminal 40. Exemplarily, when the fourth terminal portion 41 is disposed on the first wall portion 20a, the thickness direction of the fourth terminal portion 41 can be parallel to the thickness direction Z of the first wall portion 20a. Exemplarily, when the fourth terminal portion 41 is disposed on the second wall portion 20b, the thickness direction of the fourth terminal portion 41 can be parallel to the thickness direction of the second wall portion 20b.

[0336] The first terminal portion 31 including the first thinning portion 312 is disposed larger, which can increase the heat dissipation area and improve the heat exchange efficiency. The fourth terminal portion 41 can have a smaller area, thereby saving space and improving the energy density of the battery monomer 6. The thickness of the first thinning portion 312 is small, and the influence of the first thinning portion 312 on the energy density of the battery monomer 6 is small.

[0337] In addition, the first terminal portion 31 is disposed larger, which can also increase the heat exchange area between the heat exchange member 9 and the first terminal portion 31, and improve the heat exchange efficiency.

[0338] In some embodiments, the projection area of the first terminal portion 31 along the thickness direction thereof is 1.2-5 times the projection area of the fourth terminal portion 41 along the thickness direction thereof, and optionally, the projection area of the first terminal portion 31 along the thickness direction thereof is 2-3 times the projection area of the fourth terminal portion 41 along the thickness direction thereof.

[0339] As an example, the projection area of the first terminal portion 31 along the thickness direction thereof is equal to S1; the projection 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.

[0340] Setting S1 / S2 to be greater than or equal to 1.2 allows the first terminal portion 31 to have a larger heat dissipation area, improving heat dissipation efficiency and reducing the internal temperature rise of the battery cell 6. Setting S1 / S2 to be less than or equal to 5 can, to some extent, balance the overcurrent capacity of the first terminal portion 31 and the fourth terminal portion 41.

[0341] In addition, limiting S1 / S2 to 1.2-5 can also make the heat exchange area between the first thinned part 312 and the heat exchanger 9 larger, thereby improving the heat exchange efficiency.

[0342] The embodiments of this application can, to a certain extent, balance the heat dissipation area of ​​the first terminal portion 31, the current carrying capacity of the first terminal portion 31, and the current carrying capacity of the fourth terminal portion 41, thereby improving the cycle performance of the battery cell 6.

[0343] In some embodiments, the fourth terminal portion 41 is generally rectangular. The length of the fourth terminal portion 41 is L3, and the width of the fourth terminal portion 41 is W3.

[0344] Optionally, (L2×W2) / (L3×W3) is 1.2-5, or optionally 2-3.

[0345] In some embodiments, a second electrode terminal 40 is disposed on a 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 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.

[0346] S1, S2, and S3 satisfy: 0.2≤(S1+S2) / S3≤0.8.

[0347] Setting (S1+S2) / S3 to be greater than or equal to 0.2 allows the first terminal portion 31 and the fourth terminal portion 41 to have a larger exposed area, thereby improving the heat dissipation and current carrying capacity of the first electrode terminal 30 and the second electrode terminal 40, and improving the cycle performance of the battery cell 6. Setting (S1+S2) / S3 to be less than or equal to 0.8 allows for the provision of installation space for other components and maintains the distance between the first terminal portion 31 and the second terminal portion 32, reducing the risk of short circuits.

[0348] Optionally, (S1+S2) / S3 can be 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0349] Optionally, 0.3≤(S1+S2) / S3≤0.5.

[0350] Optionally, S1 / S2 can be 1.5-3, or optionally 2-3.

[0351] In some embodiments, the second electrode terminal 40 is arranged at 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.

[0352] In the case where the heat exchange efficiency of the heat exchange member 9 and the first terminal portion 31 meets the requirement, the heat exchange member 9 can not exchange heat with the fourth terminal portion 41, so that the volume of the heat exchange member 9 can be reduced, the layout difficulty of the heat exchange member 9 can be reduced, and the energy density of the battery 2 can be improved.

[0353] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projection area of the first thinning portion 312 is greater than the projection area of the fourth terminal portion 41. Optionally, the projection area of the first thinning portion 312 is 1.5-3 times the projection area of the fourth terminal portion 41.

[0354] In some embodiments, the housing 20 is provided with a second electrode lead-out hole 222.

[0355] The second electrode lead-out hole 222 can be arranged at 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 arranged at the first wall portion 20a and penetrates the first wall portion 20a in the thickness direction Z of the first wall portion 20a.

[0356] The second electrode lead-out hole 222 can be one or multiple.

[0357] 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 with other shapes.

[0358] By arranging the second electrode lead-out hole 222, the electrical connection between the fourth terminal portion 41 and the second tab 13 can be facilitated.

[0359] In some embodiments, the second electrode terminal 40 further 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 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.

[0360] 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.

[0361] The sixth terminal portion 43 and the fifth terminal portion 42 can be integrally formed. Alternatively, the sixth terminal portion 43 and the fifth terminal portion 42 can be separately formed and fixedly connected by welding, clamping, bonding or other means.

[0362] The sixth terminal portion 43 can be one or multiple.

[0363] The sixth terminal portion 43 and the fourth terminal portion 41 can be made of the same material or different materials.

[0364] 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 be connected to the second tab 13 through other conductive structures (e.g., a jumper).

[0365] In some embodiments, the sixth terminal portion 43 and the fifth terminal portion 42 are integrally formed, 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.

[0366] In some embodiments, the fourth terminal portion 41 is provided with a second through hole 414 that penetrates the fourth terminal portion 41. A part of the sixth terminal portion 43 is accommodated in the second through hole 414 and connected to the fourth terminal portion 41.

[0367] For example, the second through hole 414 can be a stepped hole.

[0368] The end of the sixth terminal portion 43 away from the second terminal portion 32 can or can not extend out of the second through hole 414.

[0369] During 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 to the fourth terminal portion 41. By providing the second through hole 414, the assembly process can be simplified.

[0370] 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.

[0371] In some embodiments, the sixth terminal portion 43 is riveted to the fourth terminal portion 41.

[0372] 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 extend out of the second through hole 414, so as to reduce the risk of the sixth terminal portion 43 interfering with the connection between the fourth terminal portion 41 and the second busbar 7b.

[0373] Optionally, the second electrode terminal 40 is provided on the first wall portion 20a, and the second electrode lead-out hole 222 has an axis parallel to the thickness direction Z of the first wall portion 20a.

[0374] In some embodiments, the second electrode terminal 40 includes a sixth terminal portion 43. The fourth terminal portion 41 and the fifth terminal portion 42 can have a small area, and therefore, the sixth terminal portion 43 can be used to 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.

[0375] In some embodiments, the first electrode terminal 30 is a positive electrode terminal, and the second electrode terminal 40 is a negative electrode terminal.

[0376] 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 first terminal portion 31 is made of aluminum or an aluminum alloy, the second terminal portion 32 is made of aluminum or an aluminum alloy, and the third terminal portion 33 is made of aluminum or an aluminum alloy.

[0377] The base metal of the second terminal portion 32 is the same as the base metal of the first tab 12.

[0378] 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 fifth terminal portion 42 is made of copper or a copper alloy, and the sixth terminal portion 43 is made of copper or a copper alloy.

[0379] The base metal of the sixth terminal portion 43 is the same as the base metal of the second tab 13.

[0380] 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. For example, the first plate 41e is provided with a recess, and the second plate 41f is accommodated in the recess.

[0381] 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.

[0382] The base metal of the first plate 41e is the same as the base metal of the second bus member 7b, facilitating welding. The base metal of the first terminal portion 31 is the same as the base metal of the first bus member 7a, facilitating welding. The first bus member 7a and the second bus member 7b are made of the same material.

[0383] Compared with aluminum, copper has a smaller resistivity and a stronger heat conduction ability. The first tab 12 is more likely to generate heat and slower to conduct heat outward than the second tab 13; therefore, heat exchange between the heat exchange member 9 and the first terminal portion 31 can increase 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.

[0384] 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.

[0385] 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.

[0386] Optionally, the area of the first solder print 80a is greater than the area of the second solder print 80b.

[0387] Optionally, the length of the first solder print 80a is greater than the length of the second solder print 80b.

[0388] 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.

[0389] 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.

[0390] The first terminal portion 31 has a larger area to achieve heat exchange with the heat exchange member 9. By providing the second terminal portion 32 with a larger area, the difference in strength between the first terminal portion 31 and the second terminal portion 32 can be reduced, the deformation of the second terminal portion 32 when the battery monomer 6 is subjected to external impact can be reduced, and the stability of the fixation of the first electrode terminal 30 to the first wall portion 20a can be improved.

[0391] 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 flow capacity between the second terminal portion 32 and the fifth terminal portion 42 can be reduced.

[0392] In some embodiments, the projection area of the second terminal portion 32 in the thickness direction thereof is 1.2-5 times the projection area of the fifth terminal portion 42 in the thickness direction thereof.

[0393] Optionally, the projection 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 of the projection area of the fifth terminal portion 42 along the thickness direction thereof.

[0394] Optionally, the projection area of the second terminal portion 32 along the thickness direction thereof is 2-3 times of the projection area of the fifth terminal portion 42 along the thickness direction thereof.

[0395] The embodiments of the present application can balance the overcurrent capacity of the first electrode terminal 30 and the overcurrent capacity of the second electrode terminal 40 to some extent, and improve the cycle performance of the battery monomer 6.

[0396] In some embodiments, the battery monomer 6 can be charged at a charge rate of 2C-6C.

[0397] In some embodiments, the charging time of the battery monomer 6 from 10% SOC to 80% SOC is less than or equal to 10.5 minutes under room temperature conditions.

[0398] As an example, the room temperature can be an ambient temperature of 30°C.

[0399] The SOC refers to the state of charge of the battery monomer 6.

[0400] For example, 100% SOC and 0% SOC are defined as follows: the battery monomer 6 is charged to the upper limit voltage of battery charging at a constant current charge rate of 0.33C, and then charged at a constant voltage of 0.05C, which corresponds to the state of 100% SOC of the battery monomer; the battery monomer 6 is discharged to the cut-off voltage at a constant current discharge rate of 0.33C, which corresponds to the state of 0% SOC of the battery monomer. For example, the upper limit voltage of battery charging and the cut-off voltage to discharge are marked on the packaging film of the battery monomer.

[0401] For example, the charging time of the battery monomer 6 from 10% SOC to 80% SOC is 10.5 minutes, 10 minutes, 9.5 minutes, 9 minutes, 8.5 minutes, 8 minutes, 7.5 minutes, 7 minutes, 6.5 minutes, 6 minutes, 5.5 minutes, 5 minutes or a range composed of any two of the above values.

[0402] In the embodiments of the present application, the battery monomer 6 has a fast charging capability, which can save charging time and improve user experience. During the fast charging process of the battery monomer 6, the first terminal portion can exchange heat with the heat exchange member, thereby reducing the temperature rise of the battery monomer 6 and reducing the risk of thermal runaway of the battery monomer.

[0403] FIG. 12 is a structural schematic diagram of a terminal cover assembly provided by some embodiments of the present application.

[0404] Referring to FIG. 12, in some embodiments, the first body portion 311 and the first thinning portion 312 are arranged along the first direction X, the size W21 of the first body portion 311 along the second direction Y is less than the size W22 of the first thinning portion 312 along the second direction Y, and the thickness direction Z of the first wall portion 20a, the first direction X, and the second direction Y are perpendicular to each other.

[0405] In the first direction X, the size of the first body portion 311 can be greater than, equal to, or less than the size of the first thinning portion 312.

[0406] The first thinning portion 312 has a larger size in the second direction Y, which can increase the exposed area of the first thinning portion 312 and further improve the heat dissipation efficiency and the cycle performance of the battery cell 6. The thickness of the first thinning portion 312 is smaller, and increasing the size of the first thinning portion 312 along the second direction Y has less impact on the energy density of the battery cell than increasing the size of the first body portion 311 along the second direction Y.

[0407] In addition, the first thinning portion 312 has a larger size in the second direction Y, which can increase the heat exchange area between the first thinning portion 312 and the heat exchange member, further improve the heat exchange efficiency, and improve the cycle performance of the battery cell 6.

[0408] In some embodiments, the first terminal portion 31 is provided with a first recessed portion 313 recessed away from the surface of the first wall portion 20a relative to the first body portion 311.

[0409] In some embodiments, the size L22 of the first thinning portion 312 along the first direction X can be greater than the size L21 of the first body portion 311 along the first direction X, to further increase the heat exchange area.

[0410] In some embodiments, the size W22 of the first thinning portion 312 in the second direction Y is greater than the width W3 of the fourth terminal portion 41.

[0411] Optionally, the size W21 of the first body portion 311 in the second direction Y is equal to the width W3 of the fourth terminal portion 41.

[0412] FIG. 13 is a structural schematic diagram of an end cover assembly of a battery cell according to some embodiments of the present application.

[0413] In some embodiments, the first body portion 311 and the first thinning portion 312 are arranged apart along the first direction X, and the first direction X is perpendicular to the thickness direction Z of the first wall portion 20a.

[0414] The first main body part 311 and the first thinning part 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 first thining part 312, and thus improve the heat dissipation effect.

[0415] In some embodiments, the first main body part 311 is connected to the second terminal part through at least one third terminal part 33, and the first thinning part 312 is connected to the second terminal part through at least one third terminal part 33.

[0416] The two third terminal parts 33 can respectively fix the first main body part 311 and the first thinning part 312 to the first wall part 20a, so as to keep the relative positions of the first main body part 311 and the first thinning part 312 fixed.

[0417] Exemplarily, part of the heat of the first main body part 311 can be conducted to the first thinning part 312 and the heat exchange member 9 through the third terminal part 33 and the second terminal part, so as to be quickly dissipated.

[0418] In some embodiments, the surface of the first main body part 311 facing the first wall part 20a is flush with the surface of the first thinning part 312 facing the first wall part 20a.

[0419] In some embodiments, the area of the first thinning part 312 is greater than the area of the fourth terminal part 41.

[0420] FIG. 14 is a structural schematic view of an end cover assembly of a battery cell according to some embodiments of the present application; and FIG. 15 is a top view of the end cover assembly shown in FIG. 14.

[0421] Referring to FIG. 14, in some embodiments, the second electrode terminal 40 includes a fourth terminal part 41 located on the outside of the shell 20, and the fourth terminal part 41 is used to connect the second bus member of the battery and exchange heat with the heat exchange member.

[0422] In the cycle process of the battery 2, both the first terminal part 31 and the fourth terminal part 41 can exchange heat with the heat exchange member, so as to further improve the heat dissipation capacity of the battery cell 6, reduce the temperature rise of the battery cell 6, improve the cycle performance and cycle life of the battery cell 6, and reduce the risk of thermal runaway of the battery cell 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 part 41, so as to reduce the temperature rise of the electrode assembly, improve the cycle performance and cycle life of the battery cell 6. The fourth terminal part 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.

[0423] In some embodiments, the fourth terminal portion 41 away from the surface of the shell 20 is configured to be connected with the heat exchange member. As an example, the fourth terminal portion 41 away from the surface of the shell 20 can be a flat surface or a stepped surface.

[0424] In some embodiments, the second electrode terminal 40 is disposed on the first wall portion 20a. The second solder print 80b is configured to at least partially overlap the heat exchange member in the thickness direction Z of the first wall portion 20a.

[0425] In some embodiments, the second electrode terminal 40 includes a fourth terminal portion 41 located on the outer side of the shell 20, the fourth terminal portion 41 including a second main body portion 411 and a second thinned portion 412, the thickness of the second main body portion 411 being greater than the thickness of the second thinned portion 412.

[0426] In the first direction X, the size of the second main body portion 411 can be the same as or different from the size of the second thinned portion 412; in the second direction Y, the size of the second main body portion 411 can be the same as or different from the size of the second thinned portion 412.

[0427] The second main body portion 411 and the second thinned portion 412 can be connected or separated. Optionally, the second main body portion 411 and the second thinned portion 412 are directly connected.

[0428] The second main body portion 411 has a greater thickness than the second thinned portion 412, which is not easy to be melted through when soldering with other components, thereby improving the reliability of the battery cell. As an example, the second main body portion 411 can be used for soldering with the second current collecting component, and since the second main body portion 411 has a greater thickness, the soldering strength can be increased, the overcurrent capacity can be improved, and the heat generation can be reduced. By providing the second thinned portion 412, the exposed area of the second electrode terminal 40 can be increased, thereby improving the heat dissipation capacity of the battery cell 6, reducing the temperature rise inside the battery cell 6, and improving the cycle performance of the battery cell 6. The second thinned portion 412 has a smaller thickness, thereby reducing the impact of the second thinned portion 412 on the energy density of the battery cell 6.

[0429] In some embodiments, the second main body portion 411 is used to connect with the second current collecting component 7b of the battery. As an example, the second current collecting component 7b is soldered with the second main body portion 411; optionally, the second current collecting component 7b is laser soldered with the second main body portion 411. The second main body portion 411 has a greater thickness, which is not easy to be melted through when soldering.

[0430] In some embodiments, the second thinned portion 412 is used to exchange heat with the heat exchange member 9 of the battery.

[0431] The second thinned portion 412 can be in contact with the heat exchange member 9 for heat exchange, or can indirectly exchange heat with the heat exchange member through other heat conduction structures.

[0432] During the cycling process of the battery 2, the current flows through the second busbar 7b and the fourth terminal part 41, causing the fourth terminal part 41 and the second busbar 7b to generate heat. The second thinning part 412 can exchange heat with the heat exchange member 9, thereby improving the heat dissipation capacity of the battery monomer 6, reducing the temperature rise of the battery monomer 6, improving the cycling performance and cycling life of the battery monomer 6, and reducing the risk of thermal runaway of the battery monomer 6 during the rapid charging process. The second electrode terminal 40 is connected with the second tab 13, and the heat of the second tab 13 can also be conducted to the heat exchange member 9 through the second thinning part 412, thereby reducing the temperature rise of the electrode assembly 10 and improving the cycling performance and cycling life of the battery monomer 6.

[0433] The second main body part 411 and the second thinning part 412 can respectively play the roles of transmitting current and dissipating heat.

[0434] The second busbar 7b and the heat exchange member 9 act on different parts of the fourth terminal part 41, respectively, so that the risk of interference between the second busbar 7b and the heat exchange member 9 can be reduced.

[0435] 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, the heat generation can be reduced, and the structural strength of the second electrode terminal 40 can be improved, thereby improving the stability of the connection between the second electrode terminal 40 and the shell 20.

[0436] 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.

[0437] In some embodiments, the second main body part 411 is connected to the fifth terminal part 42 through at least one sixth terminal part 43, and the second thinning part 412 is connected to the fifth terminal part 42 through at least one sixth terminal part 43.

[0438] In some embodiments, the second main body part 411 is configured to at least partially overlap and connect with the second busbar in the thickness direction Z of the first wall part 20a, and the second thinning part 412 is configured to at least partially overlap with the heat exchange member in the thickness direction Z.

[0439] In some embodiments, the second busbar is arranged on the side of the second main body part 411 away from the first wall part 20a and is connected to the second main body part 411.

[0440] In some embodiments, the heat exchange member is arranged on the side of the second thinning part 412 away from the first wall part 20a.

[0441] In some embodiments, the thickness of the second main body part 411 is greater than or equal to 3 mm.

[0442] In some embodiments, the thickness of the second main portion 411 is equal to the thickness of the first main portion 311, and the thickness of the second thinning portion 412 is equal to the thickness of the first thinning portion 312.

[0443] In some embodiments, the ratio of the thickness of the second main portion 411 to the second thinning portion 412 is 1.2-3, which can be 1.2, 1.5, 2, 2.5, or 3.

[0444] In some embodiments, the second main portion 411 extends beyond the second thinning portion 412 in a direction away from the first wall portion 20a.

[0445] In some embodiments, the fourth terminal portion 41 has a second recessed portion 413 on a side away from the first wall portion 20a, and the second thinning portion 412 is a bottom wall of the second recessed portion 413.

[0446] In some embodiments, the second busbar component is laser welded with the second main portion 411.

[0447] In some embodiments, the second recessed portion 413 is located on a side of the second main portion 411 along the first direction X. An end of the second recessed portion 413 away from the second main portion 411 along the first direction X can extend to an edge of the fourth terminal portion 41.

[0448] In some embodiments, along the second direction Y, the second recessed portion 413 penetrates through the fourth terminal portion 41.

[0449] In some embodiments, in the thickness direction Z of the first wall portion 20a, the depth of the second recessed portion 413 is 0.1mm-2mm.

[0450] In some embodiments, the depth of the second recessed portion 413 is equal to the depth of the first recessed portion 313.

[0451] In some embodiments, as viewed from the thickness direction Z, the area of the second thinning portion 412 is greater than the area of the second main portion 411. The second thinning portion 412 has a smaller thickness, and increasing the area of the second thinning portion 412 has less impact on the energy density of the battery cell than increasing the area of the second main portion 411. Increasing the second thinning portion 412 can increase the exposed area of the fourth terminal portion 41 and increase the heat dissipation efficiency.

[0452] In addition, increasing the area of the second thinning portion 412 can also increase the heat exchange area between the fourth terminal portion 41 and the heat exchange component.

[0453] In some embodiments, the second body portion 411 and the second thinning portion 412 are arranged along the first direction X, and a dimension of the second body portion 411 along the second direction Y is less than or equal to a dimension of the second thinning portion 412 along the second direction Y. Alternatively, the dimension of the second body portion 411 along the second direction Y is less than the dimension of the second thinning portion 412 along the second direction Y.

[0454] In some embodiments, a dimension of the second body portion 411 along the second direction Y is equal to a dimension of the first body portion 311 along the second direction Y. A dimension of the second thinning portion 412 along the second direction Y is equal to a dimension of the first thinning portion 312 along the second direction Y.

[0455] In some embodiments, the second body portion 411 and the second thinning portion 412 can be arranged continuously along the first direction X or can be arranged intermittently along the first direction X.

[0456] In some embodiments, a dimension of the second body portion 411 along the first direction X is less than or equal to a dimension of the second thinning portion 412 along the second direction Y. Alternatively, the dimension of the second body portion 411 along the first direction X is less than the dimension of the second thinning portion 412 along the first direction X.

[0457] 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, a projected area of the first thinning portion 312 is greater than or equal to a projected area of the second thinning portion 412, and a projected area of the first body portion 311 is greater than or equal to a projected area of the second body portion 411.

[0458] Alternatively, in the thickness direction Z of the first wall portion 20a, the projected area of the first thinning portion 312 is greater than the projected area of the second thinning portion 412, and the projected area of the first body portion 311 is greater than the projected area of the second body portion 411.

[0459] In some embodiments, in the first direction X, a dimension of the first thinning portion 312 is greater than a dimension of the second thinning portion 412.

[0460] In some embodiments, the second electrode terminal 40 is arranged at the first wall portion 20a. A surface of the second body portion 411 away from the first wall portion 20a includes a third region, and a surface of the second thinning portion 412 away from the first wall portion 20a includes a fourth region. The third region is configured to overlap and connect with the second busbar member in the thickness direction Z. The fourth region is configured to overlap with the heat exchange member in the thickness direction Z.

[0461] As an example, the third region is arranged in abutment with the second busbar member.

[0462] As an example, in the thickness direction Z, a projection of the fourth region is located within a projection of the heat exchange member.

[0463] The third region and the fourth region can be directly connected or spaced apart.

[0464] In some embodiments, the fourth region has a larger area than the third region. The larger area of the fourth region 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.

[0465] 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 second region 31b has a larger area than the fourth region. The first tab and the first electrode terminal 30 are both made of copper, and the second tab and a portion of the second electrode terminal 40 are made of copper. The first tab and the first electrode terminal 30 generate more heat. The second region 31b is set to be larger than the fourth region, which can improve the heat exchange efficiency between the first electrode terminal 30 and the heat exchange member and reduce the temperature difference between the first tab and the second tab.

[0466] 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, and can be 2-3.

[0467] 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.

[0468] In some embodiments, the second electrode terminal 40 is arranged on the first wall portion 20a. The first main body portion 311, the first thinning portion 312, the second thinning portion 412, and the second main body portion 411 are arranged along the first direction X.

[0469] The first main body portion 311 and the second main body portion 411 are respectively arranged at both ends of the first wall portion 20a along the first direction X, which helps arrange the plurality of battery cells 6 into groups.

[0470] In addition, the first thinning portion 312 and the second thinning portion 412 are arranged adjacent to each other along the first direction X, and the same heat exchange member can simultaneously exchange heat with the first thinning portion 312 and the second thinning portion 412, thereby simplifying the structure of the battery.

[0471] In some embodiments, the first region 31a, the second region 31b, the fourth region, and the third region are sequentially and spaced apart along the first direction X, and the first direction X is perpendicular to the thickness direction Z.

[0472] The second region 31b and the fourth region are arranged adjacent to each other along the first direction X, and the same heat exchange member can simultaneously exchange heat with the second region 31b and the fourth region, thereby simplifying the structure of the battery.

[0473] FIG. 16 is a structural schematic diagram of an end cover assembly of a battery cell according to some embodiments of the present application.

[0474] Referring to FIG. 16, in some embodiments, the second body part 411 and the second thinning part 412 can be spaced apart along the first direction X.

[0475] Optionally, the second body part 411 is connected to the fifth terminal part 42 through a sixth terminal part 43, and the second thinning part 412 is connected to the fifth terminal part 42 through a sixth terminal part 43.

[0476] Optionally, the second body part 411 and the second thinning part 412 are both copper-aluminum composite plates.

[0477] In some embodiments, the first thinning part 312, the first body part 311, the second body part 411, and the second thinning part 412 are arranged along the first direction X, which is perpendicular to the thickness direction Z. The first body part 311 and the second body part 411 are arranged opposite to each other along the first direction X, which helps arrange the plurality of battery cells 6 into groups.

[0478] When the plurality of battery cells 6 are arranged along the first direction X, the first thinning part 312 of one battery cell 6 is adjacent to the second thinning part 412 (or the first thinning part 312) of another battery cell 6, and the same heat exchange member can simultaneously exchange heat with two battery cells 6, thereby simplifying the structure of the battery.

[0479] In some embodiments, the second region 31b, the first region 31a, the third region, and the fourth region are sequentially and spaced apart along the first direction X, which is perpendicular to the thickness direction Z. When the 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 (or the second region 31b) of another battery cell 6, and the same heat exchange member can simultaneously exchange heat with two battery cells 6, thereby simplifying the structure of the battery 2.

[0480] FIG. 17 is a simplified schematic diagram of a battery cell according to some embodiments of the present application.

[0481] Referring to FIG. 17, in some embodiments, the shell 20 includes a second wall part 20b arranged opposite to the first wall part 20a, and the second electrode terminal 40 is arranged on the second wall part 20b.

[0482] Arranging the first electrode terminal 30 and the second electrode terminal 40 on the first wall part 20a and the second wall part 20b respectively can make the first terminal part 31 have a larger area, thereby improving the heat exchange efficiency and the overcurrent capacity and improving the cycle performance of the battery cell 6.

[0483] The first electrode terminal 30 and the second electrode terminal 40 are arranged at opposite ends of the housing 20, which can also reduce the risk of short circuit.

[0484] In some embodiments, the first electrode terminal 30 includes a first body part 311 and a first thinning part 312, which are arranged at intervals along the first direction X.

[0485] In some embodiments, the second electrode terminal 40 includes a second body part 411 and a second thinning part 412, which are arranged at intervals along the first direction X.

[0486] In some embodiments, in the thickness direction Z of the first wall part 20a, the projection area of the first terminal part 31 is S1, and the projection area of the first wall part 20a is S3. S1 and S3 satisfy: 0.2≤S1 / S3≤0.8; optionally, 0.3≤S1 / S3≤0.5.

[0487] Setting S1 / S3 to be greater than or equal to 0.3 can make the first terminal part 31 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. Setting S1 / S3 to be less than or equal to 0.8 can reserve installation space for other components and reduce the impact of increasing the energy density of the battery cell 6 by the first terminal part 31.

[0488] In some embodiments, in the thickness direction Z of the first wall part 20a, the projection area of the fourth terminal part 41 is S2, and the projection area of the first wall part 20a is S3. S2 and S3 satisfy: 0.2≤S2 / S3≤0.8; optionally, 0.3≤S2 / S3≤0.5.

[0489] Setting S2 / S3 to be greater than or equal to 0.3 can make the fourth terminal part 41 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. Setting S2 / S3 to be less than or equal to 0.8 can reserve installation space for other components and reduce the impact of increasing the energy density of the battery cell 6 by the fourth terminal part 41.

[0490] In some embodiments, heat exchange members can be arranged on both sides of the battery cell 6. The heat exchange member located on one side of the battery cell 6 exchanges heat with the first electrode terminal 30, and the heat exchange member located on the other side of the battery cell 6 exchanges heat with the second electrode terminal 40.

[0491] FIG. 18 is a cross-sectional view of a battery according to some embodiments of the present application.

[0492] Referring to FIG. 18, in some embodiments, the battery 2 includes the battery cell 6, the first busbar member 7a, and the heat exchange member 9. The first busbar member 7a is connected to the first main body portion 311. At least part of the heat exchange member 9 is located on the side of the first wall portion 20a facing away from the electrode assembly and exchanges heat with the first thinned portion 312.

[0493] In some embodiments, the battery 2 further includes a second busbar member 7b connected to the fourth terminal portion 41. Optionally, the second busbar member 7b is connected to the second main body portion 411.

[0494] In some embodiments, in the thickness direction Z of the first wall portion 20a, at least part of the first thinned portion 312 is located between the heat exchange member 9 and the first wall portion 20a.

[0495] The heat exchange member 9 can exchange heat with the first thinned portion 312, thereby improving the heat dissipation efficiency of the battery cell 6 and improving the cycle performance of the battery cell 6.

[0496] In some embodiments, the battery 2 includes the case 5, and the battery cell 6 and the first busbar member 7a are accommodated in the case 5.

[0497] In some embodiments, a plurality of battery cells 6 are accommodated in the case 5.

[0498] 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.

[0499] 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.

[0500] In some embodiments, the case wall and the first thinned portion 312 of the first electrode terminal 30 are bonded by the insulating heat-conductive adhesive 9a.

[0501] In some embodiments, the case wall and the second thinned portion 412 of the second electrode terminal 40 are bonded by the insulating heat-conductive adhesive 9a.

[0502] In some embodiments, a plurality of battery cells 6 are arranged along the first direction X.

[0503] In some embodiments, the heat exchange member 9 is a heat exchange pipe extending along the second direction Y.

[0504] Exemplarily, in the thickness direction Z of the first wall portion 20a, one heat exchange pipe at least partially overlaps with the first thinned portion 312 of one battery cell 6, and the second thinned portion 412 of another battery cell 6 at least partially overlaps.

[0505] According to some embodiments of the present application, the present application also provides a battery as claimed in any one of the preceding embodiments, wherein the battery is used to provide power for an electric device. The electric device can be any of the devices or systems as described above.

[0506] Referring to FIGS. 3-8 and 18, the present application provides a battery cell 6, which includes a housing 20, an electrode assembly 10, a first electrode terminal 30, and a second electrode terminal 40.

[0507] The electrode assembly 10 is accommodated in the housing 20 and includes first and second tabs 12 and 13 of opposite polarity.

[0508] The housing 20 includes a first wall portion 20a, which is provided with a first electrode lead-out hole 221 and a second electrode lead-out hole 222.

[0509] 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 portion 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 portion of the first wall portion 20a is located between the first terminal portion 31 and the second terminal portion 32.

[0510] 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 portion 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 portion of the first wall portion 20a is located between the fourth terminal portion 41 and the fifth terminal portion 42.

[0511] The first terminal portion 31 includes a first main body portion 311 and a first thinning portion 312 arranged in the first direction X, and the thickness of the first main body portion 311 is greater than the thickness of the first thinning portion 312. The side of the first terminal portion 31 away from the first wall portion 20a has a first recessed portion 313, and the first thinning portion 312 is the bottom wall of the first recessed portion 313. The third terminal portion 33 is two, and the two third terminal portions 33 are respectively connected to the first main body portion 311 and the first thinning portion 312.

[0512] The fourth terminal portion 41 comprises a second main body portion 411 and a second thinning portion 412 arranged along the first direction X, and the thickness of the second main body portion 411 is greater than the thickness of the second thinning portion 412. The fourth terminal portion 41 has a second recessed portion 413 away from one side of the first wall portion 20a, and the second thinning portion 412 is the bottom wall of the second recessed portion 413. The sixth terminal portion 43 is two, and the two sixth terminal portions 43 are connected to the second main body portion 411 and the second thinning portion 412 respectively.

[0513] The first main body portion 311, the first thinning portion 312, the second thinning portion 412 and the second main body portion 411 are arranged along the first direction X.

[0514] The first main body portion 311 is used to be connected to the first busbar component 7a of the battery 2, and the second main body portion 411 is used to be connected to the second busbar component 7b of the battery 2. The first thinning portion 312 and the second thinning portion 412 are used to exchange heat with the heat exchange member 9.

[0515] 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.

[0516] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part 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 on 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 including a first main body portion and a first thinned portion, the first main body portion having a thickness greater than a thickness of the first thinned portion.

2. The battery cell of claim 1, wherein, The first main body portion extends beyond the first thinned portion in a direction away from the first wall portion.

3. The battery cell of claim 1 or 2, wherein, A first recess is formed on a side of the first terminal portion away from the first wall portion, and the first thinned portion is a bottom wall of the first recess.

4. The battery cell of claim 3, wherein, In a thickness direction of the first wall portion, a depth of the first recess is 0.1 mm to 2 mm.

5. The battery cell of any one of claims 1-4, wherein, The first main body portion and the first thinned portion are disposed in a first direction, a dimension of the first main body portion in a second direction is less than a dimension of the first thinned 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.

6. The battery cell of any one of claims 1-5, wherein, The first main body portion and the first thinned portion are spaced apart in a first direction, and the first direction is perpendicular to the thickness direction of the first wall portion.

7. The battery cell of any one of claims 1-6, wherein, The first main body portion and the first thinned portion are disposed in a first direction, and the first direction is perpendicular to the thickness direction of the first wall portion. In the first direction, a dimension of the first thinned portion is greater than a dimension of the first main body portion.

8. The battery cell of any one of claims 1-7, wherein, 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 connected to the second terminal portion, the second terminal portion is 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 at least one of the first main body portion and the first thinned portion is connected to the third terminal portion. In the thickness direction of the first wall portion, a portion of the first wall portion is between the first terminal portion and the second terminal portion.

9. The battery cell of claim 8, wherein, The second terminal portion and the third terminal portion are integrally formed.

10. The battery cell of claim 8 or 9, wherein, At least one of the first main body portion and the first thinned portion is provided with a first through hole, and the first through hole penetrates in the thickness direction of the first wall portion. A portion of the third terminal portion is accommodated in the first through hole and connected to the first terminal portion.

11. The battery cell of claim 10, wherein, In the thickness direction, an end of the third terminal portion away from the second terminal portion does not extend beyond the first through hole. 12.The battery cell of claim 10 or 11, wherein the first thinned portion is configured to exchange heat with a heat exchange member of the battery cell; at least one of the third terminal portions is configured to at least partially overlap the heat exchange member in the thickness direction and is connected to the first thinned portion.

13. The battery cell of any one of claims 8-12, wherein, At least one of the third terminal portions is directly connected to the first main body portion.

14. The battery cell of any one of claims 8-13, wherein, The first electrode terminal includes a plurality of third terminal portions spaced apart; The first main body portion is connected to the second terminal portion through at least one of the third terminal portions, and the first thinned portion is connected to the second terminal portion through at least one of the third terminal portions.

15. The battery cell of any one of claims 8-14, wherein, The first main body part and the first thinning part are arranged along a first direction parallel to a length direction of the first wall part; The first main body part has a first edge at an end away from the first thinning part, and the first thinning part has a second edge at an end away from the first main body part; The first main body part and the first thinning part are each provided with a first through hole, and the two third terminal parts are respectively arranged through the two first through holes and connected to the first main body part and the first thinning part; 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.

16. The battery cell of any one of claims 8-15, wherein, A cross section of the third terminal part perpendicular to a thickness direction of the first wall part is circular, elliptical, or track-shaped.

17. The battery cell of any one of claims 8-16, wherein, The first tab is welded to the second terminal part and forms a first welding mark.

18. The battery cell of claim 17, wherein, The first thinning part is configured to exchange heat with a heat exchange member of the battery; The first welding mark is configured to at least partially overlap the heat exchange member in the thickness direction of the first wall part.

19. The battery cell of any one of claims 8-18, wherein, In the thickness direction of the first wall part, a projection area of the first terminal part is greater than a projection area of the second terminal part.

20. The battery cell of any one of claims 8-19, wherein, In the thickness direction of the first wall part, the projection area of the second terminal part is 0.2-0.5 times the projection area of the first wall part.

21. The battery cell of any one of claims 1-20, wherein, In the thickness direction of the first wall part, the projection area of the first terminal part is 0.2-0.5 times the projection area of the first wall part.

22. The battery cell of claims 1-21, wherein, The first main body part is configured to connect with a first busbar component of a battery, and the first thinning part is configured to exchange heat with a heat exchange member of the battery.

23. The battery cell of claim 22, wherein, The first main body part is configured to at least partially overlap and connect with the first busbar component in a thickness direction of the first wall part, and the first thinning part is configured to at least partially overlap the heat exchange member in the thickness direction.

24. The battery cell of claim 22 or 23, wherein, The first terminal part is configured to connect with the heat exchange member away from a surface of the first wall part.

25. The battery cell of any one of claims 22-24, wherein, The surface of the first main body part away from the first wall part includes a first region, and the surface of the first thinning part away from the first wall part includes a second region; The first region is configured to overlap and connect with the first busbar component in the thickness direction of the first wall part, and the second region is configured to overlap the heat exchange member in the thickness direction.

26. The battery cell of claim 25, wherein, The first region is arranged apart from the second region.

27. The battery cell of claim 25 or 26, wherein, An area of the second region is greater than an area of the first region.

28. The battery cell of any one of claims 25-27, wherein, A ratio of the area of the first region to a projection area of the first terminal part in the thickness direction is greater than or equal to 1.5%.

29. The battery cell of any one of claims 25-28, wherein, A ratio of the area of the second region to a projection area of the first terminal part in the thickness direction is greater than or equal to 10%.

30. The battery cell of any one of claims 1-29, wherein, The electrode assembly further includes a second tab, and the first tab and the second tab are opposite in polarity. The battery cell further comprises a second electrode terminal arranged at the shell, and the second electrode terminal is electrically connected to the second tab.

31. The battery cell of claim 30, wherein, The second electrode terminal comprises a fourth terminal portion located outside the shell, and the fourth terminal portion comprises a second main body portion and a second thinned portion, and a thickness of the second main body portion is greater than a thickness of the second thinned portion.

32. The battery cell of claim 31, wherein, The second main body portion is configured to be connected to a second busbar of a battery, and the second thinned portion is configured to exchange heat with a heat exchange member of the battery.

33. The battery cell of claim 31 or 32, wherein, The second electrode terminal is arranged at the first wall portion; The first thinned portion, the first main body portion, the second main body portion, and the second thinned portion are arranged along a first direction, and the first direction is perpendicular to the thickness direction; or the first main body portion, the first thinned portion, the second thinned portion, and the second main body portion are arranged along the first direction.

34. The battery cell of any one of claims 30-33, wherein, The second electrode terminal comprises a fourth terminal portion located outside the shell; A projection area of the first terminal portion along a thickness direction thereof is greater than a projection area of the fourth terminal portion along a thickness direction thereof.

35. The battery cell of claim 34, wherein, The projection area of the first terminal portion along the thickness direction thereof is 1.2-5 times the projection area of the fourth terminal portion along the thickness direction thereof, and optionally, the projection area of the first terminal portion along the thickness direction thereof is 2-3 times the projection area of the fourth terminal portion along the thickness direction thereof.

36. The battery cell of any one of claims 30-35, wherein, The shell is provided with a first electrode lead-out hole and a second electrode lead-out hole; The first electrode terminal further comprises 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, and 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 comprises a fourth terminal portion, a fifth terminal portion, and a sixth terminal portion, the fourth terminal portion is located outside the shell, the fifth terminal portion is located inside the shell and is electrically connected to the second tab, and 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. A projection area of the second terminal portion along a thickness direction thereof is greater than a projection area of the fifth terminal portion along a thickness direction thereof.

37. The battery cell of claim 36, wherein, The projection area of the second terminal portion along the thickness direction thereof is 1.2-5 times the projection area of the fifth terminal portion along the thickness direction thereof, and optionally, the projection area of the second terminal portion along the thickness direction thereof is 2-3 times the projection area of the fifth terminal portion along the thickness direction thereof.

38. The battery cell of any one of claims 30-37, wherein, The second electrode terminal is arranged at the first wall portion, and the second electrode terminal comprises a fourth terminal portion located outside the first wall portion; In the thickness direction of the first wall portion, a projection area of the first terminal portion is S1, a projection area of the fourth terminal portion is S2, and a projection 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.

39. The battery cell of claim 30, wherein, The housing comprises a second wall portion, the second wall portion is 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.

40. The battery cell of any one of claims 1-39, wherein, The housing comprises a second wall portion, and the battery cell comprises a pressure relief mechanism disposed on the second wall portion.

41. The battery cell of any one of claims 1-40, wherein, The first electrode terminal is a positive electrode terminal, and a material of the first electrode terminal comprises aluminum.

42. The battery cell of any one of claims 1-41, wherein, The first wall portion is provided with an electrolyte injection hole.

43. The battery cell of any one of claims 1-42, wherein, The housing comprises a housing body and an end cover, the housing body has an opening, and the end cover is connected to the housing body and covers the opening. The end cover is the first wall portion.

44. A battery, comprising: the battery cell according to any one of claims 1-43; a first busbar component connected to the first main body portion; and a heat exchange member, at least a portion of the heat exchange member is located on a side of the first wall portion away from the electrode assembly and exchanges heat with the first thinning portion. In a thickness direction of the first wall portion, at least a portion of the first thinning portion is located between the heat exchange member and the first wall portion.

45. The battery of claim 44, wherein, 46. The battery according to claim 44 or 45, further comprising a box body. The battery cell and the first busbar component are accommodated in the box body, and the heat exchange member is disposed outside the box body.

47. An electric device, comprising the battery according to any one of claims 44-46, the battery being configured to provide electric energy. ​

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