Battery cell, battery and electric device

Abstract

The embodiment of the utility model provides a battery monomer, a battery and a power utilization device. The battery cell includes a housing, an electrode assembly, and a first electrode terminal. The housing includes a first wall portion. The electrode assembly is accommodated in the housing, and the electrode assembly comprises a first tab. The first electrode terminal is arranged on the first wall part and electrically connected to the first tab, the first electrode terminal comprises a first terminal part located on the outer side of the first wall part, the first terminal part comprises a first main body part and a first thinned part, and the thickness of the first main body part is larger than that of the first thinned part.

Description

Technical Field

[0001] The present application relates to the field of battery technologies, and more particularly, to a battery cell, a battery, and an electrical device. Background Art

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

[0003] In the development of battery technologies, how to improve the cycle performance of battery cells is a research direction in battery technologies. Summary of the Utility Model

[0004] The present application provides a battery cell, a battery, and an electrical device, which can improve the cycle performance of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, which includes a housing, an electrode assembly, and a first electrode terminal. The housing includes a first wall portion. The electrode assembly is accommodated in the housing, and the electrode assembly includes a first tab. The first electrode terminal is disposed on the first wall portion and electrically connected to the first tab. The first electrode terminal includes a first terminal portion located outside the first wall portion. The first terminal portion includes a first main body portion and a first thinning portion, and the thickness of the first main body portion is greater than the thickness of the first thinning portion.

[0006] The first main body portion has a relatively large thickness, and it is not easily melted through when welded to other components, thereby improving the reliability of the battery cell. Exemplarily, the first main body portion can be used to weld to a first busbar component. Since the first main body portion has a relatively large thickness, the welding strength can be increased, the overcurrent capacity can be improved, and heat generation can be reduced. By providing the first thinning portion, the exposed area of the first electrode terminal can be increased, thereby enhancing 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 thinning portion has a relatively small thickness, thereby reducing the impact of adding the first thinning portion on the energy density of the battery cell.

[0007] In some embodiments, the first main body portion extends beyond the first thinning portion in a direction away from the first wall portion.

[0008] In the thickness direction of the first wall portion, the surface of the first thinning portion away from the first wall portion is closer to the first wall portion than the surface of the first thinning portion away from the first wall portion, so as to reserve more space on the side of the first thinning portion away from the first wall portion, facilitating the arrangement of other components and improving the space utilization rate.

[0009] In some embodiments, the first terminal portion has a first recess on the side away from the first wall portion, and the first thinning portion is the bottom wall of the first recess.

[0010] By providing the first recess, space can be provided for other components of the battery, improving the space utilization rate in the thickness direction of the first wall portion.

[0011] In some embodiments, in the thickness direction of the first wall portion, the depth of the first recess is 0.1 mm - 2 mm.

[0012] Limiting the depth of the first recess to be greater than or equal to 0.1 mm can provide more space for other components and improve the space utilization rate. Limiting the depth of the first recess to be less than or equal to 2 mm can reduce the risk of deformation of the first thinning portion when the battery cell is subjected to an external impact, improving the reliable performance of the battery cell.

[0013] In some embodiments, the first main body portion and the first thinning portion are arranged along a first direction, the dimension of the first main body portion along a second direction is smaller than the dimension 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 in pairs.

[0014] The first thinning portion has a larger dimension in the second direction, which can increase the exposed area of the first thinning portion, further improve the heat dissipation efficiency, and improve the cycling performance of the battery cell. The thickness of the first thinning portion is smaller. Compared with increasing the dimension of the first main body portion along the second direction, increasing the dimension of the first thinning portion along the second direction has a smaller impact on the energy density of the battery cell.

[0015] In some embodiments, the first main body portion and the first thinning portion are arranged at intervals 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 to the processing and forming of parts, and can also get rid of the size limitation caused by manufacturing capacity limitations, providing a larger area of the first thinning portion, thereby improving the heat dissipation effect.

[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. In the first direction, the dimension of the first thinning portion is larger than the dimension of the first main body portion.

[0017] The first thinning portion has a dimension larger than that of the first main body portion in the first direction, which can have a larger exposed area, thereby improving the heat dissipation efficiency, reducing the temperature rise inside the battery cell, and improving the cycling performance of the battery cell. The thickness of the first thinning portion is smaller than the thickness of the first main body portion. Compared with increasing the dimension of the first main body portion along the first direction, increasing the dimension of the first thinning portion along the first direction has a smaller impact on the volume and weight of the battery cell.

[0018] 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 a part of the third terminal portion is received 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.

[0019] In some embodiments, the second terminal portion and the third terminal portion are of an integrally formed structure, which can improve the connection strength between the second terminal portion and the third terminal portion, reduce the resistance, and enhance the overcurrent capacity.

[0020] In some embodiments, at least one of the first main body portion and the first thinning portion is provided with a first through hole that penetrates in the thickness direction of the first wall portion. A part of the third terminal portion is received in the first through hole and is connected to the first terminal portion.

[0021] During assembly, the third terminal portion can first be passed through the first electrode lead-out hole and the first through hole, and then the third terminal portion can be connected to the first terminal portion. By providing the first through hole, the assembly process can be simplified.

[0022] In some embodiments, in the thickness direction, the end of the third terminal portion away from the second terminal portion does not extend beyond the first through hole, so as to reduce the risk of the third terminal portion interfering with the connection between the first terminal portion and other components.

[0023] In some embodiments, the first thinning portion is used to exchange heat with the heat exchange member of the battery. 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.

[0024] During the cycling 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.

[0025] In some embodiments, at least one third terminal portion is directly connected to the first main body portion, which can shorten the conduction path between the first tab and the first main body portion, reduce the resistance, and reduce heat generation.

[0026] In some embodiments, the first electrode terminal includes a plurality of third terminal portions arranged at intervals.

[0027] The first main body portion is connected to the second terminal portion through at least one third terminal portion to shorten the conduction path between the first tab and the first main body portion. The first thinning portion is connected to the second terminal portion through at least one third terminal portion to shorten the heat transfer path between the first tab and the first thinning portion.

[0028] In some embodiments, the first main body portion and the first thinning portion are arranged along a first direction, and the first direction is parallel to the length direction of the first wall portion. One end of the first main body portion away from the first thinning portion has a first edge, and one end of the first thinning portion away from the first main body portion has a second edge. Both the first main body portion and the first thinning portion are provided with first through holes, and two third terminal portions respectively pass through the two first through holes and are respectively connected to the first main body portion and the first thinning portion. In the first direction, the distance between the first edge and the axis of the first through hole close to the first edge is D1, the distance between the second edge and the axis of the first through hole close to the second edge is D2, and the 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.

[0029] Viewed from the thickness direction, the two third terminal portions are approximately symmetrically arranged, which can improve the stability of the first terminal portion and enhance the structural strength of the first electrode terminal.

[0030] In some embodiments, the cross-section of the third terminal portion perpendicular to the thickness direction of the first wall portion is circular, elliptical or racetrack-shaped.

[0031] In some embodiments, the first tab is welded to the second terminal portion to form a first weld mark. Welding the first tab directly to the second terminal portion can shorten the conduction path between the first tab and the second terminal portion, reduce the resistance, and decrease the heat generation of the first tab and the second terminal portion.

[0032] In some embodiments, the first thinning portion is used to exchange heat with a heat exchange member of the battery. The first weld mark is configured to at least partially overlap the heat exchange member in the thickness direction of the first wall portion. When current passes through the first weld mark, the first weld mark generates heat. The embodiments of the present application can reduce the distance between the first weld mark and the heat exchange member, improve the heat dissipation efficiency of the first weld mark, and lower the temperature rise of the first weld mark.

[0033] In some embodiments, in the thickness direction of the first wall portion, the projected area of the first terminal portion is larger than the projected area of the second terminal portion. Compared with the second terminal portion, the first terminal portion can have a larger area, which can improve the heat dissipation efficiency of the first terminal portion; on the premise that the current-carrying area meets the requirements, the second terminal portion can have an area smaller than that of the first terminal portion, thereby saving the internal space of the housing and increasing the energy density of the battery cell.

[0034] In some embodiments, in the thickness direction of the first wall portion, the projected area of the second terminal portion is 0.2 - 0.5 times the projected area of the first wall portion.

[0035] The ratio of the projected area of the second terminal portion to the projected area of the first wall portion is greater than or equal to 0.2. A relatively large connection area and current-carrying area can be provided between the second terminal portion and the first tab, thereby reducing the resistance, decreasing the heat generation of the second terminal portion and the first tab, and reducing the temperature rise of the battery cell. The ratio of the projected area of the second terminal portion to the projected area of the first wall portion is less than or equal to 0.5, which can reserve installation space for other components inside the housing, reduce the risk of interference and short circuit between the second terminal portion and other components, and improve the reliability of the battery cell.

[0036] In some embodiments, in the thickness direction of the first wall portion, the projected area of the first terminal portion is 0.2 - 0.5 times the projected area of the first wall portion.

[0037] The ratio of the projected area of the first terminal portion to the projected area of the first wall portion is greater than or equal to 0.2. The first terminal portion has a relatively large exposed area, thereby improving the heat exchange efficiency and enhancing the cycle performance and reliability of the battery cell. The ratio of the projected area of the first terminal portion to the projected area of the first wall portion is less than or equal to 0.5, which can reserve installation space for other components of the battery cell.

[0038] In some embodiments, the first main body portion is used to connect to the first current collecting component of the battery, and the first thinning portion is used to exchange heat with the heat exchanger of the battery.

[0039] During the cycle of the battery, current flows through the first current collecting component and the first terminal portion, causing heat generation in the first terminal portion and the first current collecting component. The first thinning portion can exchange heat with the heat exchanger, thereby enhancing 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 during rapid charging of the battery cell. The first electrode terminal is connected to the first tab, and the heat of the first tab can also be conducted to the heat exchanger 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.

[0040] 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 exchanger in the thickness direction.

[0041] The first main body portion and the first current collecting component are arranged along the thickness direction, which can increase the connection strength and current-carrying area between the first main body portion and the first current collecting component and reduce heat generation. The first thinning portion and the heat exchanger are arranged in the thickness direction, which can increase the heat exchange area between the first thinning portion and the heat exchanger and improve the heat exchange efficiency. The first current collecting component and the heat exchanger can share space in the thickness direction, thereby improving the space utilization rate in the thickness direction and enhancing the energy density of the battery.

[0042] In some embodiments, the surface of the first terminal portion away from the first wall portion is configured to be connected to the heat exchange member.

[0043] 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.

[0044] The first busbar component and the heat exchange member act on the first region and the second region respectively, which can reduce the risk of interference between the first 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, improving the space utilization rate.

[0045] In some embodiments, the first region and the second region are spaced apart to reduce the risk of interference between the first busbar component and the heat exchange member caused by assembly errors.

[0046] In some embodiments, the area of the second region is larger 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 performance of the battery cell.

[0047] 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 there is a large connection area and high connection strength between the first main body portion and the first busbar component, improving the current-carrying capacity between the first main body portion and the first busbar component, reducing heat generation, and reducing the temperature rise.

[0048] 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 there is a large heat exchange area between the first thinning portion and the heat exchange member, 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 temperature rise of the electrode assembly, and improving the cycle performance of the battery cell.

[0049] In some embodiments, the electrode assembly further includes a second tab, and the first tab and the second tab have opposite polarities. The battery cell further includes a second electrode terminal disposed on the outer shell, and the second electrode terminal is electrically connected to the second tab.

[0050] In some embodiments, the second electrode terminal includes a fourth terminal portion located outside the outer shell. 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.

[0051] The second main body portion has a larger thickness compared to the second thinning portion, and it is not easily melted through when welded to other components, thereby improving the reliability of the battery cell. Exemplarily, the second main body portion can be used for welding with the second busbar component. Since the second main body portion has a larger thickness, the welding strength can be increased, the current-carrying capacity can be improved, and heat generation can be reduced. By providing the second thinning portion, the exposed area of the second electrode terminal can be increased, thereby enhancing the heat dissipation capacity of the battery cell, reducing the temperature rise inside the battery cell, and improving the cycling performance of the battery cell. The second thinning portion has a smaller thickness, thereby reducing the impact of adding the second thinning portion on the energy density of the battery cell.

[0052] In some embodiments, the second main body portion is used to connect to the second busbar component of the battery, and the second thinning portion is used to exchange heat with the heat exchanger of the battery.

[0053] During the cycling of the battery, current flows through the second busbar component and the fourth terminal portion, causing heat generation in the fourth terminal portion and the second busbar component. The second thinning portion can exchange heat with the heat exchanger, thereby enhancing the heat dissipation capacity of the battery cell, reducing the temperature rise of the battery cell, improving the cycling performance and cycling life of the battery cell, and reducing the risk of thermal runaway during rapid charging of the battery cell. The second electrode terminal is connected to the second tab, and the heat of the second tab can also be conducted to the heat exchanger through the second thinning portion, thereby reducing the temperature rise of the electrode assembly and improving the cycling performance and cycling life of the battery cell.

[0054] In some embodiments, the second electrode terminal is disposed on the first wall portion. The first thinning portion, the first main body portion, the second main body portion, and the second thinning portion are arranged along a first direction, and the first direction is perpendicular to the thickness direction; alternatively, the first main body portion, the first thinning portion, the second thinning portion, and the second main body portion are arranged along the first direction. The embodiments of the present application facilitate arranging multiple battery cells into a group.

[0055] In some embodiments, the second electrode terminal includes a fourth terminal portion located outside the housing. The projected area of the first terminal portion in its own thickness direction is larger than the projected area of the fourth terminal portion in its own thickness direction.

[0056] Setting the first terminal portion including the first thinning portion to be larger can increase the heat dissipation area and improve the heat exchange efficiency. The fourth terminal portion can have a smaller area, thereby saving space and enhancing the energy density of the battery cell. The thickness of the first thinning portion is smaller, and the impact of the first thinning portion on the energy density of the battery cell is smaller.

[0057] In some embodiments, the projected area of the first terminal portion in its own thickness direction is 1.2 - 5 times the projected area of the fourth terminal portion in its own thickness direction. Optionally, the projected area of the first terminal portion in its own thickness direction is 2 - 3 times the projected area of the fourth terminal portion in its own thickness direction.

[0058] The embodiments of the present application can, to a certain extent, balance the heat dissipation area of the first terminal portion, the current-carrying capacity of the first terminal portion, and the current-carrying capacity of the fourth terminal portion, and improve the cycle performance of the battery cell.

[0059] In some embodiments, the housing is provided with a first electrode lead-out hole and a second electrode lead-out hole. The first electrode terminal further includes a second terminal portion and a third terminal portion. The second terminal portion is located inside the first wall portion and is electrically connected to the first tab. At least a part of the third terminal portion is received in the first electrode lead-out hole, and the third terminal portion connects the second terminal portion and the first terminal portion. The second electrode terminal further includes a fourth terminal portion, a fifth terminal portion, and a sixth terminal portion. The fourth terminal portion is located outside the housing. The fifth terminal portion is located inside the housing and is electrically connected to the second tab. At least a part of the sixth terminal portion is received in the second electrode lead-out hole, and the sixth terminal portion connects the fifth terminal portion and the fourth terminal portion. The projected area of the second terminal portion in the direction of its own thickness is larger than the projected area of the fifth terminal portion in the direction of its own thickness.

[0060] Compared with the fifth terminal portion, the second terminal portion can have a larger current-carrying area, thereby reducing the heat generation of the second terminal portion. By setting the second terminal portion to have a larger area, the strength difference between the first terminal portion and the second terminal portion can be reduced, the deformation of the second terminal portion when the battery cell is subjected to an external impact can be reduced, and the stability of fixing the first electrode terminal to the first wall portion can be improved.

[0061] In some embodiments, the projected area of the second terminal portion in the direction of its own thickness is 1.2 - 5 times that of the fifth terminal portion in the direction of its own thickness. Optionally, the projected area of the second terminal portion in the direction of its own thickness is 2 - 3 times that of the fifth terminal portion in the direction of its own thickness.

[0062] The embodiments of the present application can, to a certain extent, balance the current-carrying capacity of the first electrode terminal and the current-carrying capacity of the second electrode terminal, and improve the cycle performance of the battery cell.

[0063] In some embodiments, the second electrode terminal is disposed on the first wall portion, and the second electrode terminal includes a fourth terminal portion located outside the first wall portion. In the thickness direction of the first wall portion, the projected area of the first terminal portion is S1, the projected area of the fourth terminal portion is S2, and the projected area of the first wall portion is S3. S1, S2, and S3 satisfy: 0.2 ≤ (S1 + S2) / S3 ≤ 0.8; optionally, 0.3 ≤ (S1 + S2) / S3 ≤ 0.5.

[0064] Setting (S1 + S2) / S3 to be greater than or equal to 0.2 can make the overall exposed area of the first terminal portion and the fourth terminal portion relatively large, thereby improving the heat dissipation capacity and overcurrent capacity of the first electrode terminal and the heat dissipation capacity and overcurrent capacity of the second electrode terminal, and improving the cycling performance of the battery cell. Setting (S1 + S2) / S3 to be less than or equal to 0.8 can reserve installation space for other components, maintain the distance between the first terminal portion and the second terminal portion, and reduce the risk of short circuit.

[0065] In some embodiments, the housing includes a second wall portion that is disposed opposite to the first wall portion, and the second electrode terminal is disposed on the second wall portion. In the thickness direction of the first wall portion, the projected area of the first terminal portion is S1, and the projected area of the first wall portion is S3. S1 and S3 satisfy: 0.2 ≤ S1 / S3 ≤ 0.8; optionally, 0.3 ≤ S1 / S3 ≤ 0.5.

[0066] Setting S1 / S3 to be greater than or equal to 0.3 can make the first terminal portion have a relatively large area, thereby improving the heat dissipation capacity and overcurrent capacity of the first electrode terminal and improving the cycling performance of the battery cell. 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 first terminal portion on the energy density of the battery cell.

[0067] In some embodiments, the housing includes a second wall portion, and the battery cell includes a pressure relief mechanism disposed on the second wall portion.

[0068] Disposing the pressure relief mechanism on the second wall portion can reserve more space on the first wall portion to install the first electrode terminal, enable the first terminal portion to have a larger exposed area, improve the heat dissipation capacity of the first terminal portion, reduce the temperature rise of the first terminal portion, and improve the cycling performance and cycling life of the battery cell.

[0069] In some embodiments, the first electrode terminal is a positive terminal, and the material of the first electrode terminal includes aluminum. Aluminum has good thermal conductivity and electrical conductivity. Using an aluminum first electrode terminal can reduce the heat generation of the first electrode terminal.

[0070] In some embodiments, the first wall portion is provided with an electrolyte injection hole. During the production process of the battery cell, electrolyte can be injected into the housing through the electrolyte injection hole.

[0071] In some embodiments, the housing includes a housing body and an end cap. The housing body has an opening, and the end cap is connected to the housing body and covers the opening. The end cap is the first wall portion.

[0072] Compared with the housing body, the end cap generally has a larger thickness. Disposing the first electrode terminal on the end cap can improve the connection strength between the first electrode terminal and the end cap, enhance the stability of the first electrode terminal, and reduce the risk of the first electrode terminal shifting.

[0073] In a second aspect, an embodiment of the present application provides a battery, which includes a battery cell provided in any one of the embodiments of the first aspect, a first current collecting component, and a heat exchange component. The first current collecting component is connected to the first main body portion. At least a part of the heat exchange component is located on a side of the first wall portion facing away from the electrode assembly and exchanges heat with the first thinning portion.

[0074] In some embodiments, in the thickness direction of the first wall portion, at least a part of the first thinning portion is located between the heat exchange component and the first wall portion. 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 cycling performance of the battery cell.

[0075] In some embodiments, the battery further includes a box body. The battery cell and the first current collecting component are accommodated in the box body, and the heat exchange component is provided outside the box body. The embodiment of the present application can save the internal space of the box body and improve the space utilization rate.

[0076] In a third aspect, an embodiment of the present application provides an electrical device, including the battery provided in any one of the embodiments of the second aspect, and the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the drawings.

[0078] Figure 1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0079] Figure 2 is a schematic diagram of a battery provided in some embodiments of the present application;

[0080] Figure 3 is a schematic diagram of a partial structure of a battery provided in some embodiments of the present application;

[0081] Figure 4 is a schematic cross-sectional view of a battery provided in some embodiments of the present application;

[0082] Figure 5 is a schematic structural diagram of a battery provided in some embodiments of the present application;

[0083] Figure 6 is Figure 5 an exploded schematic diagram of the battery cell shown;

[0084] Figure 7 is Figure 4 an enlarged schematic diagram at box A;

[0085] Figure 8 is Figure 4 An enlarged schematic view at box B;

[0086] Figure 9 is a schematic structural view of an end cap assembly of a battery cell provided in some embodiments of the present application;

[0087] Figure 10 is Figure 9 A top view schematic of the end cap assembly shown;

[0088] Figure 11 is Figure 9 A bottom view schematic of the end cap assembly shown;

[0089] Figure 12 is a schematic structural view of an end cap assembly provided in some other embodiments of the present application;

[0090] Figure 13 is a schematic structural view of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0091] Figure 14 is a schematic structural view of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0092] Figure 15 is Figure 14 A top view schematic of the end cap assembly shown;

[0093] Figure 16 is a schematic structural view of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0094] Figure 17 is a simplified schematic of a battery cell provided in some other embodiments of the present application;

[0095] Figure 18 is a cross-sectional schematic of a battery provided in some embodiments of the present application.

[0096] In the drawings, the drawings are not drawn to actual scale.

[0097] Explanation of reference numerals:

[0098] 1, vehicle; 2, battery; 3, controller; 4, motor; 5, box body; 5a, first box body part; 5b, second box body part; 6, battery cell; 7, bus bar component; 7a, first bus bar component; 7b, second bus bar component; 8, heat exchange plate; 9, heat exchange member; 9a, thermal conductive adhesive;

[0099] 10, electrode assembly; 11, electrode main body; 12, first tab; 13, second tab;

[0100] 20. Outer shell; 20a. First wall portion; 20b. Second wall portion; 21. Housing; 22. End cap; 221. First electrode lead-out hole; 222. Second electrode lead-out hole; 223. Electrolyte injection hole;

[0101] 30. First electrode terminal; 31. First terminal portion; 311. First main body portion; 312. First thinning portion; 313. First concave 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;

[0102] 40. Second electrode terminal; 41. Fourth terminal portion; 411. Second main body portion; 412. Second thinning portion; 413. Second concave portion; 414. Second through hole; 41e. First plate; 41f. Second plate; 42. Fifth terminal portion; 43. Sixth terminal portion;

[0103] 50. End cap assembly;

[0104] 60. Pressure relief mechanism;

[0105] 70. Sealing sheet; 80a. First welding mark; 80b. Second welding mark;

[0106] X. First direction; Y. Second direction; Z. Thickness direction. Detailed implementation manner

[0107] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

[0108] Unless otherwise defined, all the technical and scientific terms used in this application have the same meanings as those commonly understood by those skilled in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments, and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects, rather than to describe a specific order or primary-secondary relationship.

[0109] Reference to "embodiment" in this application means that the specific features, structures, or characteristics described in connection with the embodiment may be included in at least one embodiment of this application. The phrase appearing in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0110] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected", "connected to", and "attached" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific situations.

[0111] The term "and / or" in this application is merely a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the front and rear associated objects.

[0112] In the embodiments of this application, the same reference numerals 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 this application shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are only illustrative and should not constitute any limitation to this application.

[0113] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a particular range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 to 120 and 80 to 110 are listed for a specific parameter, ranges of 60 to 110 and 80 to 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 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 stated, the numerical range "a to b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0 to 5" means that all real numbers between "0 to 5" are fully listed herein, and "0 to 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0114] The term "plurality" as used in this application means two or more (including two).

[0115] Currently, from the perspective of the development of the market situation, the application of batteries is becoming more and more widespread. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in multiple fields such as aerospace. With the continuous expansion of the battery application field, the market demand is also continuously increasing.

[0116] A battery generally refers to a single physical module that includes a plurality of battery cells to provide a higher voltage and capacity. A battery cell can be the smallest unit that makes up a battery.

[0117] With the development of batteries, especially their widespread use in daily life, users hope that the batteries can be charged faster to meet the needs of the fast-paced modern life. However, during the fast charging process, the heat generation of the battery cells increases, so that the battery cells are maintained in a high temperature range throughout the charging process, which affects the cycle performance and cycle life of the battery and exacerbates the risk of battery thermal runaway.

[0118] In view of this, an embodiment of the present application provides a battery cell. The electrode terminal of the battery cell includes an exposed main body portion and a thinning portion, and the thickness of the thinning portion is less than that of the main body portion. The main body portion can be used for welding with a busbar component. The main body portion has a relatively large thickness, which can reduce the risk of the main body portion being melted through, improve the overcurrent capacity, and reduce heat generation. By providing the thinning portion, the exposed area of the electrode terminal can be increased, thereby enhancing the heat dissipation capacity of the battery cell, reducing the temperature rise inside the battery cell, and improving the cycling performance of the battery cell. The thinning portion does not need to be welded to the busbar component and can have a relatively small thickness, thereby reducing the impact of adding the thinning portion on the energy density of the battery cell.

[0119] The battery described in the embodiments of the present application is applicable to an electrical device using a battery. The electrical device can be a device using a battery as a power source or various energy storage systems using a battery as an energy storage element. The electrical device can be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric airplane toy, and the like. The spacecraft can include an airplane, a rocket, a space shuttle, a spaceship, and the like.

[0120] For the convenience of description, the following embodiments take the electrical device as a vehicle as an example for illustration.

[0121] Figure 1 It is a schematic structural diagram of a vehicle provided by some embodiments of the present application.

[0122] As Figure 1 shown, a battery 2 is provided inside the vehicle 1, and the battery 2 can be provided 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 the operating power source of the vehicle 1.

[0123] The vehicle 1 may further include a controller 3 and a motor 4. The controller 3 is used to control the battery 2 to supply power to the motor 4. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1.

[0124] In some embodiments of the present application, the battery 2 can not only be used as the operating power source of the vehicle 1, but also as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0125] Figure 2 It is a schematic diagram of a battery provided by some embodiments of the present application.

[0126] Referring to Figure 2 , in some embodiments, the battery 2 includes a box body 5 and a plurality of battery cells 6 accommodated in the box body 5.

[0127] The battery cell 6 can be a secondary battery cell, which refers to a battery cell 6 that can be activated by charging after discharging so that the active material can be reused.

[0128] Exemplarily, 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-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0129] As an example, the battery cell 6 can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a multi-prismatic battery cell. The multi-prismatic battery cell is, for example, a hexagonal-prismatic battery cell, etc.

[0130] Multiple battery cells 6 can be connected in series, in parallel, or in a combination of series and parallel (mixed connection). Mixed connection means that there are both series and parallel connections among multiple battery cells 6. Multiple battery cells 6 can be directly connected in series, in parallel, or in a mixed manner and then the whole formed by multiple battery cells 6 is accommodated in the box body 5. Of course, it can also be that multiple battery cells 6 are first connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a mixed manner to form a whole and are accommodated in the box body 5.

[0131] In some embodiments, the box body 5 is used to accommodate the battery cell 6, and the box body 5 can have various structures.

[0132] In some embodiments, the box body 5 can include a first box body part 5a and a second box body part 5b. The first box body part 5a and the second box body part 5b cover each other, and the first box body part 5a and the second box body part 5b jointly define an accommodation space for accommodating the battery cell 6. The second box body part 5b can be a hollow structure with one end open, and the first box body part 5a is a plate-like structure. The first box body part 5a covers the open side of the second box body part 5b to form the box body 5 with an accommodation space. Both the first box body part 5a and the second box body part 5b can also be hollow structures with one side open, and the open side of the first box body part 5a covers the open side of the second box body part 5b to form the box body 5 with an accommodation space. Of course, the first box body part 5a and the second box body part 5b can have various shapes, such as a cylinder, a cuboid, etc.

[0133] To improve the sealing performance after the connection between the first box body part 5a and the second box body part 5b, a sealing member, such as sealant, sealing ring, etc., can also be provided between the first box body part 5a and the second box body part 5b.

[0134] In some embodiments, the box body 5 can be part of the chassis structure of a vehicle. For example, part of the box body 5 can form at least part of the floor of the vehicle, or part of the box body 5 can form at least part of the cross beams and longitudinal beams of the vehicle.

[0135] In some embodiments, the battery 2 can be an energy storage device. The energy storage device includes an energy storage container, an energy storage electrical cabinet, etc.

[0136] Figure 3 It is a schematic diagram of part of the structure of the battery provided in some embodiments of the present application.

[0137] Referring to Figure 3 , in some embodiments, the battery 2 includes a plurality of battery cells 6 and a plurality of busbar components 7, and the plurality of busbar components 7 electrically connect the plurality of battery cells 6.

[0138] The plurality of busbar components 7 connect the plurality of battery cells 6 in series, parallel, or in a mixed connection.

[0139] The plurality of busbar components 7 can have the same structure or different structures.

[0140] The busbar component 7 can be a single-layer structure or a multi-layer structure.

[0141] 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.

[0142] In some embodiments, the busbar component 7 is welded to the first electrode terminal 30.

[0143] In some embodiments, the busbar component 7 has a multi-layer structure. Exemplarily, the busbar component 7 has a multi-layer structure in its own thickness direction. For example, the busbar component 7 is formed into a double-layer structure or a triple-layer structure by bending.

[0144] Each layer structure of the busbar component 7 can conduct current. By setting the busbar component 7 as a multi-layer structure, the current-carrying area of the busbar component 7 can be increased, the heat generation when the busbar component 7 is overcurrent can be reduced, the temperature rise of the battery cell 6 can be lowered, and the fast charging ability of the battery cell 6 can be improved.

[0145] On the premise that the cross-sectional area meets the requirements, the busbar component 7 is set as a multi-layer structure, which can reduce the thickness of each layer structure of the busbar component 7. During the cycling process of the battery cell 6, expansion occurs, thus stretching the layer structure of the busbar component 7 connected to the battery cell 6. The layer structure of the busbar component 7 has a small thickness and is easily deformed to adapt to the expansion deformation of the battery cell 6, thereby reducing the risk that the connection between the battery cell 6 and the busbar component 7 is torn, and improving the reliability of the battery 2.

[0146] In some embodiments, the battery 2 further includes a heat exchange plate 8, which is used for heat exchange with the outer shell of the battery cell 6.

[0147] The heat exchange plate 8 can exchange heat with the battery cell 6 during the cycling process of the battery cell 6, so that the battery cell 6 is maintained within a suitable temperature range, improving the cycling performance and cycling life of the battery cell 6, and reducing the risk of thermal runaway.

[0148] In some embodiments, in the thickness direction of the battery cell 6, the outer shell has two relatively arranged large faces. Along the thickness direction of the battery cell 6, the heat exchange plate 8 is disposed on at least one side of the battery cell 6 and exchanges heat with the large face of the battery cell 6.

[0149] The large face is the largest face among the outer surfaces of the outer shell. Exchanging heat between the large face and the heat exchange plate 8 improves the heat exchange efficiency. Furthermore, during the fast charging process, the temperature rise of the battery cell 6 is reduced, the cycling performance and cycling life of the battery cell 6 are improved, the risk of thermal runaway is reduced, and the reliability is improved.

[0150] In some embodiments, heat exchange plates 8 are provided on both sides of the battery cell 6, that is, the two large faces of the battery cell 6 exchange heat with two heat exchange plates 8 respectively.

[0151] In some embodiments, the battery 2 includes a plurality of heat exchange plates 8, and the plurality of heat exchange plates 8 are arranged along the thickness direction of the battery cell 6. Battery cells 6 are provided between adjacent heat exchange plates 8.

[0152] In some embodiments, the battery 2 further includes a heat exchange member 9, which is used for heat exchange with the electrode terminals of the battery cell 6.

[0153] The heat exchange member 9 can exchange heat only with the first electrode terminal 30, or only with the second electrode terminal 40, or can also exchange heat with both the first electrode terminal 30 and the second electrode terminal 40 at the same time.

[0154] As an example, both 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 exchanges heat with the heat exchange member 9.

[0155] As an example, for two adjacent battery cells 6, the heat exchange member 9 can exchange heat with the first electrode terminals 30 of the two battery cells 6 simultaneously, or can exchange heat with the first electrode terminal 30 of one battery cell 6 and the second electrode terminal 40 of the other battery cell 6, or can exchange heat with the first electrode terminals 30 and the second electrode terminals 40 of the two battery cells 6 simultaneously.

[0156] As an example, the heat exchange member 9 can directly exchange heat with the electrode terminal in contact, or can indirectly exchange heat with the electrode terminal through other heat conducting members.

[0157] As an example, the heat exchange member 9 can be located inside the box body 5, or can be located outside the box body 5. Optionally, the heat exchange member 9 can be located outside the box body 5 and exchange heat with the electrode terminal through the box body 5.

[0158] In some embodiments, the heat exchange member 9 includes a heat exchange tube. Exemplarily, the heat exchange tube is a flat tube.

[0159] In some embodiments, a flow channel is provided inside the heat exchange member 9; when the heat exchange medium flows through the flow channel, it exchanges heat with the electrode terminal through the heat exchange member 9.

[0160] Figure 4 Partial cross-sectional schematic diagram of the battery provided by some embodiments of the present application; Figure 5 Structural schematic diagram of the battery provided by some embodiments of the present application; Figure 6 is Figure 5 Explosion schematic diagram of the battery cell shown; Figure 7 is Figure 4 Enlarged schematic diagram at box A; Figure 8 is Figure 4 Enlarged schematic diagram at box B; Figure 9 Structural schematic diagram of the end cap assembly of the battery cell provided by some embodiments of the present application; Figure 10 is Figure 9 Top view schematic diagram of the end cap assembly shown; Figure 11 is Figure 9 Bottom view schematic diagram of the end cap assembly shown.

[0161] Referring to Figures 4 to 11 , in some embodiments, the battery cell 6 includes a housing 20 and an electrode assembly 10, and at least a part of the electrode assembly 10 is accommodated in the housing 20.

[0162] The housing 20 is a hollow structure, and an accommodation space for accommodating the electrode assembly 10 and the electrolyte is formed inside it. 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.

[0163] In some embodiments, the outer casing 20 includes a housing 21 and an end cap 22. The housing 21 has an opening, and the end cap 22 is connected to the housing 21 and covers the opening.

[0164] The housing 21 is a component for cooperating with the end cap 22 to form an internal cavity of the battery cell 6, and the formed internal cavity can be used to accommodate the electrode assembly 10, the electrolyte, and other components.

[0165] The housing 21 and the end cap 22 can be independent components. Exemplarily, an opening can be provided on the housing 21, and the end cap 22 is covered at the opening to form an internal cavity of the battery cell 6.

[0166] The housing 21 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly 10. The material of the housing 21 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of the present application do not make special restrictions on this.

[0167] The shape of the end cap 22 can be adapted to the shape of the housing 21 to cooperate with the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21. Optionally, the end cap 22 can be made of a material with certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.). In this way, the end cap 22 is not easily deformed when being squeezed or collided, so that the battery cell 6 can have higher structural strength and the reliability can also be improved.

[0168] The end cap 22 is connected to the housing 21 by welding, bonding, clamping or other means.

[0169] The housing 21 can be open at one end or both ends. In some examples, the housing 21 can be a structure with one side open, and the end cap 22 is provided as one and covers the housing 21. In other examples, the housing 21 can also be a structure with both sides open, and the end cap 22 is provided as two, and the two end caps 22 respectively cover the two openings of the housing 21.

[0170] The electrode assembly 10 is a component in the battery cell 6 where an electrochemical reaction occurs. The housing 21 can contain one or more electrode assemblies 10.

[0171] In some embodiments, the electrode assembly 10 includes a positive electrode plate and a negative electrode plate. During the charge and discharge process of the battery cell 6, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode plate and the negative electrode plate.

[0172] In some embodiments, the electrode assembly 10 further includes a separator, and the separator is disposed between the positive electrode plate and the negative electrode plate, which can play a role in preventing short circuit between the positive and negative electrodes, and at the same time can allow active ions to pass through.

[0173] In some embodiments, the positive electrode sheet may include a positive electrode current collector and a positive electrode film layer provided on at least one surface of the positive electrode current collector. Exemplarily, a portion of the positive electrode current collector where the positive electrode film layer is not provided may serve as the positive electrode tab.

[0174] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode film layer is provided on either one or both of the two opposite surfaces of the positive electrode current collector.

[0175] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer provided on at least one surface of the negative electrode current collector. Exemplarily, a portion of the negative electrode current collector where the negative electrode film layer is not provided may serve as the negative electrode tab.

[0176] In some embodiments, the electrode assembly 10 includes an electrode body 11, a first tab 12, and a second tab 13. The first tab 12 and the second tab 13 are led out from the electrode body 11. The first tab 12 and the second tab 13 have opposite polarities. In other words, one of the first tab 12 and the second tab 13 is a positive electrode tab, and the other is a negative electrode tab.

[0177] As an example, the positive electrode sheet 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 to form the electrode body 11. The positive electrode tab and the negative electrode tab may be led out from the same end of the electrode body 11, or may be led out from both ends of the electrode body 11 respectively.

[0178] In some embodiments, the electrode assembly 10 is a wound structure. The positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0179] In some embodiments, the electrode assembly 10 is a stacked structure.

[0180] As an example, multiple positive electrode sheets and multiple negative electrode sheets may be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets are alternately stacked.

[0181] As an example, multiple positive electrode sheets may be provided, and the negative electrode sheet is folded to form multiple stacked folding segments, and a positive electrode sheet is clamped between adjacent folding segments.

[0182] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form multiple stacked folding segments.

[0183] As an example, multiple separator films may be provided and are respectively provided between any adjacent positive electrode sheets or negative electrode sheets.

[0184] As an example, the separator film may be continuously provided and is provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0185] In some embodiments, the battery cell 6 includes a first electrode terminal 30 and a second electrode terminal 40 that are insulated from each other. The first electrode terminal 30 is electrically connected to the first tab 12, and the second electrode terminal 40 is electrically connected to the second tab 13.

[0186] The first electrode terminal 30 and the second electrode terminal 40 are used to electrically connect to an external circuit to enable charging or discharging of the battery cell 6.

[0187] As an example, the first electrode terminal 30 can be an independently formed component that is mounted on the housing 20. Alternatively, the first electrode terminal 30 can also be part of the housing 20.

[0188] As an example, the second electrode terminal 40 can be an independently formed component that is mounted on the housing 20. Alternatively, the second electrode terminal 40 can also be part of the housing 20.

[0189] In some embodiments, both the first electrode terminal 30 and the second electrode terminal 40 are disposed on the end cap 22. As an example, the end cap 22, the first electrode terminal 30, and the second electrode terminal 40 can be pre-assembled together and then assembled with the electrode assembly 10 and the housing 21.

[0190] Exemplarily, the battery cell 6 includes an end cap assembly 50, and the end cap assembly 50 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 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.

[0191] 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 short circuit, overcharge, etc. occur, it may cause thermal runaway inside the battery cell 6 and thus a sudden increase in pressure. In this case, the internal pressure can be released outward through the actuation of the pressure relief mechanism 60 to reduce the risk of explosion and fire of the battery cell 6.

[0192] Exemplarily, the pressure relief mechanism 60 refers to an element or component that actuates to release internal gas when the internal pressure or temperature of the battery cell 6 reaches a predetermined threshold. This threshold design varies according to different design requirements. This threshold may depend on one or several of the materials of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 6.

[0193] The pressure relief mechanism 60 can be in the form of, for example, an explosion-proof valve, a gas valve, a pressure relief valve, or a safety valve, and can specifically adopt a pressure-sensitive element or structure, that is, when the internal pressure of the battery cell 6 reaches a predetermined threshold, the pressure relief mechanism 60 performs an action or a weak area provided in the pressure relief mechanism 60 ruptures, thereby forming an opening or a channel for discharging the internal pressure. Alternatively, the pressure relief mechanism 60 can also adopt a temperature-sensitive element or structure, that is, 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 a channel for discharging the internal pressure.

[0194] When the battery cell 6 is in thermal runaway, the emissions of the battery cell 6 include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gas generated by the reaction, flame, and so on.

[0195] In some embodiments, the pressure relief mechanism 60 is disposed on the outer casing 20. Exemplarily, the pressure relief mechanism 60 can be disposed on the housing 21 or on the end cap 22.

[0196] In some embodiments, the present application provides a battery cell 6, which includes an outer casing 20, an electrode assembly 10, and a first electrode terminal 30. The outer casing 20 includes a first wall portion 20a. The electrode assembly 10 is accommodated in the outer casing 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 is 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 thinning portion 312, and the thickness t1 of the first main body portion 311 is greater than the thickness t2 of the first thinning portion 312.

[0197] The first wall portion 20a can be the end cap 22 or a wall of the housing 21.

[0198] 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.

[0199] The first electrode terminal 30 and the first tab 12 can be directly connected or indirectly connected through other conductive structures.

[0200] The first electrode terminal 30 can be one or multiple.

[0201] As an example, in the thickness direction Z of the first wall portion 20a, the first terminal portion 31 is located on the side of the end cap 22 away from the electrode body 11.

[0202] In the first direction X, the size of the first main body portion 311 may be the same as or different from the size of the first thinning portion 312. In the second direction Y, the size of the first main body portion 311 may be the same as or different from the size of the first thinning portion 312. As an example, the first direction X, the second direction Y, and the thickness direction Z of the first wall portion 20a are perpendicular to each other in pairs. As an example, the first direction X is parallel to the length direction of the first wall portion 20a, and the second direction Y is parallel to the width direction of the first wall portion 20a.

[0203] The first main body portion 311 and the first thinning portion 312 may be connected or separated.

[0204] Exemplarily, in the thickness direction Z of the first wall portion 20a, the surface of the first main body portion 311 away from the first wall portion 20a may be flush with or not flush with the surface of the first thinning portion 312 away from the first wall portion 20a.

[0205] In the embodiment of the present application, the first main body portion 311 has a larger thickness than the first thinning portion 312, and it is not easily melted through when welded to 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 larger thickness, the welding strength can be increased, the current-carrying 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 enhancing 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 impact of adding the first thinning portion 312 on the energy density of the battery cell 6.

[0206] In some embodiments, the first main body portion 311 is used to connect to the first current collecting component 7a of the battery. As an example, the first current collecting component 7a is welded to the first main body portion 311; alternatively, the first current collecting component 7a is laser welded to the first main body portion 311. The first main body portion 311 has a larger thickness and is not easily melted through during welding.

[0207] In some embodiments, the first thinning portion 312 is used to exchange heat with the heat exchanger 9 of the battery.

[0208] The first thinning portion 312 can exchange heat with the heat exchanger 9 in contact or indirectly exchange heat with the heat exchanger 9 through other heat conduction structures.

[0209] During the cycling of the battery 2, current flows through the first current collecting member 7a and the first terminal portion 31, causing heat generation in the first terminal portion 31 and the first current collecting member 7a. The first thinning portion 312 can exchange heat with the heat exchange member 9, thereby enhancing the heat dissipation capacity of the battery cell 6, reducing the temperature rise of the battery cell 6, improving the cycling performance and cycle life of the battery cell 6, and reducing the risk of thermal runaway of the battery cell 6 during rapid charging. The first electrode terminal 30 is connected to the first tab 12, and the heat of the first tab 12 can also be conducted to the heat exchange member 9 through the first thinning portion 312, thereby reducing the temperature rise of the electrode assembly 10 and improving the cycling performance and cycle life of the battery cell 6.

[0210] The first main body portion 311 and the first thinning portion 312 can respectively play the roles of current transmission and heat dissipation.

[0211] The first current collecting member 7a and the heat exchange member 9 act on different parts of the first terminal portion 31 respectively, which can reduce the risk of interference between the first current collecting member 7a and the heat exchange member 9.

[0212] In some embodiments, the thickness of the first main body portion 311 is greater than or equal to 3 mm.

[0213] In some embodiments, the ratio of the thickness of the first main body portion 311 to the thickness of the first thinning portion 312 is 1.2 - 3. Optionally, t1 / t2 is 1.2, 1.5, 2, 2.5 or 3.

[0214] 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.

[0215] 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, so as to reserve more space on the side of the first thinning portion 312 away from the first wall portion 20a for arranging other components (such as the heat exchange member 9), improving the space utilization rate.

[0216] In some embodiments, the first terminal portion 31 has a first recess 313 on a side away from the first wall portion 20a, and the first thinning portion 312 is the bottom wall of the first recess 313.

[0217] By providing the first recess 313, space can be provided for other components of the battery (such as the heat exchange member 9), improving the space utilization rate in the thickness direction Z of the first wall portion 20a.

[0218] In some embodiments, the first recess 313 is located on one side of the first main body portion 311 along the first direction X. One end of the first recess 313 away from the first main body portion 311 along the first direction X may extend to the edge of the first terminal portion 31; alternatively, one end of the first recess 313 away from the first main body portion 311 along the first direction X may not extend to the edge of the first terminal portion 31, that is, the first terminal portion 31 may further include a thickened portion (not shown), the thickness of the thickened portion is greater than the thickness of the first thinning portion 312, the first thinning portion 312 is connected between the first main body portion 311 and the thickened portion, and the first recess 313 is located between the first main body portion 311 and the thickened portion in the first direction X.

[0219] In some embodiments, along the second direction Y, the first recess 313 penetrates the first terminal portion 31.

[0220] 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 mm - 2 mm.

[0221] 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.

[0222] Defining the depth of the first recess 313 to be greater than or equal to 0.1 mm can provide more space for other components (such as the heat exchanger 9) and improve space utilization. Defining 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 thinning portion 312 when the battery cell 6 is subjected to an external impact and improve the reliable performance of the battery cell 6.

[0223] In addition, defining the depth of the first recess 313 to be less than or equal to 2 mm can also reduce the loss of heat conduction capacity caused by the thinning of the first thinning portion 312 and balance the heat exchange efficiency between the first thinning portion 312 and the heat exchanger 9 to a certain extent.

[0224] In some embodiments, when observed from the thickness direction Z, the area of the first thinning portion 312 is larger than the area of the first main body portion 311, so that the heat exchange area between the first terminal portion 31 and the heat exchanger 9 can be larger.

[0225] In some embodiments, the first main body portion 311 and the first thinning portion 312 are arranged along the first direction X, and the first direction X is perpendicular to the thickness direction Z of the first wall portion 20a. In the first direction X, the dimension L22 of the first thinning portion 312 is greater than the dimension L21 of the first main body portion 311.

[0226] The first thinning portion 312 has a dimension greater than that of the first main body portion 311 in the first direction X. It can have a larger exposed area, thereby improving the heat dissipation efficiency, reducing the temperature rise inside the battery cell 6, and improving the cycling performance of the battery cell 6. The thickness of the first thinning portion 312 is less than that of the first main body portion 311. Compared with increasing the dimension of the first main body portion 311 along the first direction X, increasing the dimension of the first thinning portion 312 along the first direction X has a smaller impact on the volume and weight of the battery cell 6.

[0227] In addition, by increasing the dimension of the first thinning portion 312 in the first direction X, the heat exchange area between the first thinning portion 312 and the heat exchange member 9 can also be increased, thereby enhancing the heat exchange efficiency.

[0228] In some embodiments, in the thickness direction Z of the first wall portion 20a, the distance between the heat exchange member 9 and the first thinning portion 312 is less than the distance between the heat exchange plate 8 and the first thinning portion 312.

[0229] In some embodiments, in the thickness direction Z of the first wall portion 20a, the heat exchange plate 8 does not overlap with the first electrode terminal 30.

[0230] In some embodiments, the housing 20 includes a housing body 21 and an end cap 22. The housing body 21 has an opening, and the end cap 22 is connected to the housing body 21 and covers the opening. The end cap 22 is the first wall portion 20a.

[0231] Compared with the housing body 21, the end cap 22 generally has a larger thickness. By disposing the first electrode terminal 30 on the end cap 22, the connection strength between the first electrode terminal 30 and the end cap 22 can be improved, the stability of the first electrode terminal 30 can be enhanced, and the risk of the first electrode terminal 30 shifting can be reduced.

[0232] During the production process of the battery cell 6, the first electrode terminal 30 and the end cap 22 can be pre-assembled and then assembled with other components such as the housing body 21 and the electrode assembly 10. The first electrode terminal 30 and the end cap 22 are provided in one piece, which can simplify the assembly process.

[0233] In some embodiments, the first wall portion 20a is provided with an electrolyte injection hole 223. During the production process of the battery cell 6, the electrolyte can be injected into the housing 20 through the electrolyte injection hole 223.

[0234] After the process related to the electrolyte injection hole 223 is completed, a sealing sheet 70 can be installed on the first wall portion 20a to seal the electrolyte injection hole 223.

[0235] 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.

[0236] Connecting the first electrode terminal 30 directly to the first tab 12 can save the traditional adapter and shorten the conduction path, reduce the resistance, and decrease heat generation. Additionally, connecting the first electrode terminal 30 directly 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.

[0237] In some embodiments, the electrode assembly 10 further includes a second tab 13, and the first tab 12 and the second tab 13 have opposite polarities. The battery cell 6 further includes a second electrode terminal 40 disposed on the housing 20, and the second electrode terminal 40 is electrically connected to the second tab 13.

[0238] The first electrode terminal 30 and the second electrode terminal 40 may be disposed on the same wall portion of the housing 20 or may be respectively disposed on two wall portions of the housing 20. Exemplarily, both the first electrode terminal 30 and the second electrode terminal 40 are disposed on the first wall portion 20a.

[0239] The second electrode terminal 40 may be directly connected to the second tab 13 or may be indirectly connected to the second tab 13 through other conductive structures.

[0240] The second electrode terminal 40 may exchange heat with the heat exchange member 9 or may not exchange heat with the heat exchange member 9.

[0241] In some embodiments, the second electrode terminal 40 is directly connected to the second tab 13. Optionally, the second electrode terminal 40 is welded to the second tab 13.

[0242] Connecting the second electrode terminal 40 directly to the second tab 13 can save the traditional adapter and shorten the conduction path, reduce the resistance, and decrease heat generation.

[0243] In some embodiments, the second electrode terminal 40 can be used to connect to the second busbar member 7b of the battery.

[0244] The first electrode terminal 30 and the second electrode terminal 40 of the battery cell 6 are generally respectively connected to two busbar members 7. The busbar member 7 connected to the first electrode terminal 30 is the first busbar member 7a, and the busbar member 7 connected to the second electrode terminal 40 is the second busbar member 7b.

[0245] As an example, two adjacent battery cells 6 are connected in series through a busbar member 7, and the busbar member 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; correspondingly, for one battery cell 6, this busbar member 7 is the first busbar member 7a, and for another battery cell 6, it is the second busbar member 7b.

[0246] In some embodiments, the housing 20 includes a second wall portion 20b, and the battery cell 6 includes a pressure relief mechanism 60 disposed on the second wall portion 20b. The second wall portion 20b may be a wall portion disposed opposite to the first wall portion 20a, or a wall portion directly connected to the first wall portion 20a.

[0247] By disposing the pressure relief mechanism 60 on the second wall portion 20b, more space can be reserved on the first wall portion 20a for installing the first electrode terminal 30, enabling the first terminal portion 31 to have a larger exposed area, improving the heat dissipation capacity of the first terminal portion 31, reducing the temperature rise of the first terminal portion 31, and improving the cycling performance and cycle life of the battery cell 6.

[0248] 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 both sides of the electrode body 11.

[0249] As an example, the second wall portion 20b is the bottom wall of the housing 21.

[0250] In some embodiments, the first electrode terminal 30 is a positive terminal, and the second electrode terminal 40 is a negative terminal. Alternatively, the first electrode terminal 30 is a negative terminal, and the second electrode terminal 40 is a positive terminal.

[0251] In some embodiments, the first electrode terminal 30 is a positive terminal, and the material of the first electrode terminal 30 includes aluminum.

[0252] Exemplarily, the material of the first electrode terminal 30 is aluminum or aluminum alloy.

[0253] Aluminum has good thermal conductivity and electrical conductivity. By using the aluminum first electrode terminal 30, the heat generation of the first electrode terminal 30 can be reduced.

[0254] In addition, by using the aluminum first electrode terminal 30, the heat exchange efficiency between the first electrode terminal 30 and the heat exchange member 9 can also be improved.

[0255] 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 terminal, and the material of the first electrode terminal 30 includes aluminum. Compared with copper, aluminum has relatively poor thermal conductivity; by providing the first thinning portion 312, the exposed area of the first electrode terminal 30 can be increased, the heat dissipation efficiency 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.

[0256] Exemplarily, by exchanging heat between the heat exchange member 9 and the first thinning portion 312, the heat dissipation efficiency of the first tab 12 to the outside can be further improved, and the temperature difference between the first tab 12 and the second tab 13 can be reduced.

[0257] In some embodiments, the projection of the first terminal portion 31 in the thickness direction Z is generally rectangular.

[0258] 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.

[0259] The first main body portion 311 and the first busbar member 7a are arranged in the thickness direction Z, which can increase the connection strength and current-carrying area between the first main body portion 311 and the first busbar member 7a, and reduce heat generation. The first thinning portion 312 and the heat exchange member 9 are arranged in the thickness direction Z, which 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 a space in the thickness direction Z, thereby improving the space utilization rate in the thickness direction Z and enhancing the energy density of the battery 2.

[0260] In some embodiments, the first busbar member 7a is disposed on a side of the first main body portion 311 away from the first wall portion 20a and is connected to the first main body portion 311.

[0261] In some embodiments, the heat exchange member 9 is disposed on a side of the first thinning portion 312 away from the first wall portion 20a.

[0262] In some embodiments, the surface of the first terminal portion 31 away from the first wall portion 20a is configured to be connected to the heat exchange member 9.

[0263] As an example, the surface of the first terminal portion 31 away from the first wall portion 20a can be a flat surface or a stepped surface.

[0264] The surface of the first terminal portion 31 away from the first wall portion 20a can be in contact connection 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 away from the first wall portion 20a can be adhesively bonded to the heat exchange member 9 with a thermally conductive adhesive.

[0265] In some embodiments, the surface of the first main body portion 311 away from the first wall portion 20a includes a first region 31a, and the surface of the first thinning portion 312 away from the first wall portion 20a includes a second region 31b. The first region 31a is configured to overlap and connect with 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 with the heat exchange member 9 in the thickness direction Z.

[0266] As an example, the first region 31a is disposed in a fitting manner with the first busbar member 7a.

[0267] 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.

[0268] The first region 31a and the second region 31b may be flush with each other, or may be offset in the thickness direction Z of the first wall portion 20a.

[0269] As an example, in Figure 10 the first region 31a and the second region 31b are shown by diagonal lines.

[0270] The first region 31a and the second region 31b may be directly connected to each other, or may be spaced apart.

[0271] The first current collecting 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 current collecting member 7a and the heat exchange member 9, and reduce the superposition of the first current collecting member 7a and the heat exchange member 9 in the thickness direction Z, improving the space utilization rate.

[0272] In some embodiments, the first region 31a and the second region 31b are spaced apart to reduce the risk of interference between the first current collecting member 7a and the heat exchange member 9 caused by assembly errors.

[0273] In some embodiments, the area of the second region 31b is larger than the area of the first region 31a. The larger area of the second region 31b can improve the heat exchange efficiency between the heat exchange member 9 and the first thinning portion 312, reduce the temperature rise of the first terminal portion 31, and improve the cycle performance and reliability performance of the battery cell 6.

[0274] In some embodiments, the ratio of the area of the first region 31a to the projected area of the first terminal portion 31 in the thickness direction Z is greater than or equal to 1.5%, so that there is a large connection area and a high connection strength between the first main body portion 311 and the first current collecting member 7a, improving the current-carrying capacity between the first main body portion 311 and the first current collecting member 7a, reducing heat generation, and reducing the temperature rise.

[0275] As an example, the ratio of the area of the first region 31a to the projected area of the first terminal portion 31 in the thickness direction Z is 1.5%, 2%, 3%, 5%, 8%, 10%, 15%, 20%, 25% or 30%.

[0276] In some embodiments, the area of the first region 31a is greater than or equal to 20 mm 2 . Optionally, the area of the first region 31a is 20 mm 2 , 25 mm 2 , 30 mm 2 , 35 mm 2 , 40 mm 2 , 45 mm 2 , 50 mm2 、 60 mm 2 、 80 mm 2 or 100 mm 2 。 There is a large connection area and high connection strength between the first main body portion 311 and the first bus component 7a, which improves the current-carrying capacity between the first main body portion 311 and the first bus component 7a, reduces heat generation, and lowers the temperature rise.

[0277] In some embodiments, 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 greater than or equal to 10%, so that there is a large heat exchange area between the first thinning portion 312 and the heat exchange member 9, improving the heat exchange efficiency between the first thinning portion 312 and the heat exchange member 9, reducing the temperature rise of the first thinning portion 312 and the temperature rise of the electrode assembly 10, and improving the cycle performance of the battery cell 6.

[0278] 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%.

[0279] 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 may be less than or equal to 40%.

[0280] In some embodiments, the first wall portion 20a is provided with a first electrode lead-out hole 221.

[0281] 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.

[0282] The first electrode lead-out hole 221 can be one or multiple.

[0283] The first electrode lead-out hole 221 can be a round hole, a rectangular hole, an oval hole, a racetrack-shaped hole or a hole of other shapes.

[0284] By providing the first electrode lead-out hole 221, it is convenient to realize the electrical connection between the first terminal portion 31 and the first tab 12.

[0285] 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 electrically connected to the first tab 12. At least a part of the third terminal portion 33 is received in the first electrode lead-out hole 221, and at least one of the first main body portion 311 and the first thinning portion 312 is connected to the third terminal portion 33. In the thickness direction Z of the first wall portion 20a, a part of the first wall portion 20a is located between the first terminal portion 31 and the second terminal portion 32.

[0286] The third terminal portion 33 and the first terminal portion 31 may be an integrally formed structure. Alternatively, the third terminal portion 33 and the first terminal portion 31 may also be independently formed and fixedly connected by welding, clamping, bonding or other means.

[0287] The third terminal portion 33 and the second terminal portion 32 may be an integrally formed structure. Alternatively, the third terminal portion 33 and the second terminal portion 32 may also be independently formed and fixedly connected by welding, clamping, bonding or other means.

[0288] The third terminal portion 33 may be one or more.

[0289] The materials of the third terminal portion 33 and the first terminal portion 31 may be the same or different.

[0290] The second terminal portion 32 may 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 may also be connected to the first tab 12 through other conductive structures (such as a transition piece).

[0291] The first wall portion 20a may 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 may clamp the first wall portion 20a from both sides, so as to achieve fixation in the thickness direction Z.

[0292] In some embodiments, the second terminal portion 32 and the third terminal portion 33 are an integrally formed structure, which can improve the connection strength between the second terminal portion 32 and the third terminal portion 33, reduce the resistance, and enhance the overcurrent capacity.

[0293] Exemplarily, the third terminal portion 33 protrudes from the surface of the second terminal portion 32 facing the first wall portion 20a.

[0294] In some embodiments, at least one of the first main body portion 311 and the first thinning portion 312 is provided with a first through hole 314, and the first through hole 314 penetrates along the thickness direction Z of the first wall portion 20a. A part of the third terminal portion 33 is received in the first through hole 314 and connected to the first terminal portion 31.

[0295] Exemplarily, the first through hole 314 may be a hole with a constant diameter or a hole with a variable diameter. For example, the first through hole 314 may be a stepped hole.

[0296] In the thickness direction Z, one end of the third terminal portion 33 away from the second terminal portion 32 may extend beyond the first through hole 314 or may not extend beyond the first through hole 314.

[0297] In the thickness direction Z, one end of the third terminal portion 33 away from the second terminal portion 32 may overlap with the first bus bar member 7a or may not overlap with the first bus bar member 7a.

[0298] In the thickness direction Z, one end of the third terminal portion 33 away from the second terminal portion 32 may overlap with the heat exchange member 9 or may not overlap with the heat exchange member 9.

[0299] During assembly, the third terminal portion 33 may first pass through the first electrode lead-out hole 221 and the first through hole 314, and then the third terminal portion 33 may be connected to the first terminal portion 31. By providing the first through hole 314, the assembly process can be simplified.

[0300] In some embodiments, both the first terminal portion 31 and the second terminal portion 32 are flat plates. The third terminal portion 33 is cylindrical.

[0301] In some embodiments, the third terminal portion 33 is riveted to the first terminal portion 31.

[0302] In some embodiments, in the thickness direction Z, one end of the third terminal portion 33 away from the second terminal portion 32 does not extend beyond 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 to other components.

[0303] 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 to the first bus bar member 7a, or reduce the risk of the third terminal portion 33 interfering with the connection of the first terminal portion 31 to the heat exchange member 9.

[0304] In some embodiments, the first thinning portion 312 is used to exchange heat with the heat exchange member 9 of the battery. 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 with the heat exchange member 9 in the thickness direction Z.

[0305] During the cycling 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 member 9 in the thickness direction Z can shorten the heat conduction path between the third terminal portion 33 and the heat exchange member 9 and improve the heat exchange efficiency.

[0306] In some embodiments, at least one third terminal portion 33 is directly connected to the first main body portion 311, which can shorten the conduction path between the first tab 12 and the first main body portion 311, reduce the resistance, and reduce heat generation.

[0307] In some embodiments, the first electrode terminal 30 includes a plurality of third terminal portions 33 arranged at intervals. By providing a plurality of third terminal portions 33, the overcurrent capacity can be improved, heat generation can be reduced, the structural strength of the first electrode terminal 30 can be enhanced, and the stability of the connection between the first electrode terminal 30 and the first wall portion 20a can be improved.

[0308] In some embodiments, the first main body portion 311 is connected to the second terminal portion 32 through at least one third terminal portion 33 to shorten the conduction 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 at least one third terminal portion 33 to shorten the heat transfer path between the first tab 12 and the first thinning portion 312.

[0309] 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 an 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 between the first main body portion 311 and the first bus bar member 7a.

[0310] Connecting the first thinning portion 312 and the third terminal portion 33, when the battery cell 6 is subjected to an 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.

[0311] In some embodiments, there are a plurality of first electrode lead holes 221, and the plurality of first electrode lead holes 221 are arranged in one-to-one correspondence with the plurality of third terminal portions 33.

[0312] In some embodiments, the first main body portion 311 and the first thinning portion 312 are arranged along the first direction X, and the first direction X is parallel to the length direction of the first wall portion 20a. One end of the first main body portion 311 away from the first thinning portion 312 has a first edge 31c, and one 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 first through holes 314, and two third terminal portions 33 respectively pass through 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.

[0313] In some embodiments, D1 / D2 is 0.9 - 1.1, and (D1 + D2) / D3 is 0.9 - 1.1.

[0314] As an example, D1 / D2 is 0.9, 0.95, 1, 1.05, or 1.1.

[0315] As an example, (D1 + D2) / D3 is 0.9, 0.95, 1, 1.05, or 1.1.

[0316] Viewed 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 enhance the structural strength of the first electrode terminal 30.

[0317] In some embodiments, D1 = D2. Optionally, D3 = 2×D1.

[0318] 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.

[0319] In some examples, the cross-section of the third terminal portion 33 is circular. Correspondingly, the first electrode lead-out hole 221 is a circular hole. The circular third terminal portion 33 is easy to process and form; the first electrode lead-out hole 221 can be sealed by a circular sealing ring, and the deformation amount of the circular sealing ring is uniform, and the sealing effect is good.

[0320] In other examples, the cross-section of the third terminal portion 33 is racetrack-shaped. Correspondingly, the first electrode lead-out hole 221 is racetrack-shaped. The racetrack-shaped third terminal portion 33 can have a larger cross-sectional area than the circular third terminal portion 33 to improve the current-carrying 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.

[0321] In still other examples, the cross-section of the third terminal portion 33 is elliptical.

[0322] In some embodiments, the first tab 12 is welded to the second terminal portion 32 to form a first weld mark 80a.

[0323] Directly welding the first tab 12 to the second terminal portion 32 can shorten the conduction 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.

[0324] In some embodiments, the first tab 12 is connected to the second terminal portion 32 by laser welding or ultrasonic welding.

[0325] In some embodiments, the first thinning portion 312 is configured to exchange heat with the heat exchanger 9 of the battery. The first welding mark 80a is configured to at least partially overlap with the heat exchanger 9 in the thickness direction Z of the first wall portion 20a.

[0326] When current passes through the first welding mark 80a, the first welding mark 80a generates heat. In the embodiments of the present application, the distance between the first welding mark 80a and the heat exchanger 9 can be reduced, the heat dissipation efficiency of the first welding mark 80a can be improved, and the temperature rise of the first welding mark 80a can be reduced.

[0327] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the first terminal portion 31 is larger than the projected area of the second terminal portion 32.

[0328] 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; on the premise that the current-carrying 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 housing 20 and increasing the energy density of the battery cell 6.

[0329] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area S1 of the first terminal portion 31 is 0.2-0.5 times the projected area S3 of the first wall portion 20a.

[0330] Optionally, S1 / S3 is 0.2, 0.3, 0.4 or 0.5.

[0331] 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 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, which can reserve installation space for other components of the battery cell 6.

[0332] In addition, by limiting S1 / S3 to 0.2-0.5, a larger area can be reserved for heat exchange with the heat exchanger 9, and the heat exchange area between the heat exchanger 9 and the first thinning portion 312 can be increased.

[0333] In some embodiments, when observed from the thickness direction Z, both the first wall portion 20a and the first terminal portion 31 are rectangular. 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.

[0334] It should be noted here that the rectangle does not require to be an absolute rectangle. For example, the four corners of the rectangle can be set as rounded corners.

[0335] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the second terminal portion 32 is 0.2-0.5 times the projected area of the first wall portion 20a.

[0336] 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. There may be a relatively large connection area and current-carrying area between the second terminal portion 32 and the first tab 12, 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, which can reserve installation space for other components inside the housing 20, reduce the risk of interference and short circuit between the second terminal portion 32 and other components, and improve the reliability of the battery cell 6.

[0337] In some embodiments, the second electrode terminal 40 includes a fourth terminal portion 41 located outside the housing 20. Exemplarily, the fourth terminal portion 41 can be used to connect to the second bus component 7b.

[0338] The second electrode terminal 40 can be disposed on the first wall portion 20a, the second wall portion 20b or other wall portions of the housing 20.

[0339] 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 also be disposed away from the heat exchange member 9 to reduce its heat exchange with the heat exchange member 9.

[0340] 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.

[0341] In some embodiments, the projected area of the first terminal portion 31 in its own thickness direction is greater than the projected area of the fourth terminal portion 41 in its own thickness direction.

[0342] The thickness direction of the first terminal portion 31 can be parallel to the thickness direction Z of the first wall portion 20a.

[0343] 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.

[0344] Making the first terminal portion 31 including the first thinning portion 312 larger 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 increasing the energy density of the battery cell 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 cell 6 is small.

[0345] In addition, making the first terminal portion 31 larger can also increase the heat exchange area between the heat exchange member 9 and the first terminal portion 31, improving the heat exchange efficiency.

[0346] In some embodiments, the projected area of the first terminal portion 31 in its own thickness direction is 1.2 - 5 times the projected area of the fourth terminal portion 41 in its own thickness direction. Optionally, the projected area of the first terminal portion 31 in its own thickness direction is 2 - 3 times the projected area of the fourth terminal portion 41 in its own thickness direction.

[0347] As an example, the projected area of the first terminal portion 31 in its own thickness direction is equal to S1; the projected area of the fourth terminal portion 41 in its own thickness direction is equal to S2. Optionally, S1 / S2 is 1.2, 1.5, 2, 2.5, 3, 3.5, 4, 4.5 or 5.

[0348] Limiting S1 / S2 to be greater than or equal to 1.2 enables the first terminal portion 31 to have a larger heat dissipation area, improving the heat dissipation efficiency and reducing the internal temperature rise of the battery cell 6. Limiting S1 / S2 to be less than or equal to 5 can balance the current-carrying capacity of the first terminal portion 31 and the fourth terminal portion 41 to a certain extent.

[0349] In addition, limiting S1 / S2 to 1.2 - 5 can also make the first thinning portion 312 and the heat exchange member 9 have a larger heat exchange area, improving the heat exchange efficiency.

[0350] The embodiments of the present application can 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 to a certain extent, improving the cycling performance of the battery cell 6.

[0351] 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.

[0352] Optionally, (L2×W2) / (L3×W3) is 1.2 - 5, and can be 2 - 3.

[0353] In some embodiments, the second electrode terminal 40 is disposed on the first wall portion 20a, and the second electrode terminal 40 includes a fourth terminal portion 41 located outside the first wall portion 20a. In the thickness direction Z of the first wall portion 20a, the 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.

[0354] S1, S2, and S3 satisfy: 0.2 ≤ (S1 + S2) / S3 ≤ 0.8.

[0355] Setting (S1 + S2) / S3 to be greater than or equal to 0.2 can make the overall exposed area of the first terminal portion 31 and the fourth terminal portion 41 larger, thereby improving the heat dissipation capacity and overcurrent capacity of the first electrode terminal 30 and the heat dissipation capacity and overcurrent capacity of the second electrode terminal 40, and improving the cycle performance of the battery cell 6. Setting (S1 + S2) / S3 to be less than or equal to 0.8 can reserve installation space for other components, maintain the distance between the first terminal portion 31 and the second terminal portion 32, and reduce the short-circuit risk.

[0356] Optionally, (S1 + S2) / S3 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8.

[0357] Optionally, 0.3 ≤ (S1 + S2) / S3 ≤ 0.5.

[0358] Optionally, S1 / S2 is 1.5 - 3, and can be 2 - 3.

[0359] In some embodiments, the second electrode terminal 40 is disposed on the first wall portion 20a, and the second electrode terminal 40 includes a fourth terminal portion 41 located outside the first wall portion 20a. In the thickness direction Z of the first wall portion 20a, the fourth terminal portion 41 does not overlap with the heat exchange member 9.

[0360] When the heat exchange efficiency between the heat exchange member 9 and the first terminal portion 31 meets the requirements, the heat exchange member 9 can not exchange heat with the fourth terminal portion 41, which can reduce the volume of the heat exchange member 9, reduce the layout difficulty of the heat exchange member 9, and improve the energy density of the battery 2.

[0361] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the first thinning portion 312 is larger than the projected area of the fourth terminal portion 41. Optionally, the projected area of the first thinning portion 312 is 1.5 - 3 times the projected area of the fourth terminal portion 41.

[0362] In some embodiments, the housing 20 is provided with a second electrode lead-out hole 222.

[0363] The second electrode lead-out hole 222 can be provided on the first wall portion 20a, the second wall portion 20b or other wall portions of the outer shell 20. As an example, the second electrode lead-out hole 222 is provided on the first wall portion 20a and penetrates through the first wall portion 20a along the thickness direction Z of the first wall portion 20a.

[0364] The second electrode lead-out hole 222 can be one or multiple.

[0365] The second electrode lead-out hole 222 can be a round hole, a rectangular hole, an oval hole, a racetrack-shaped hole or a hole of other shapes.

[0366] By providing the second electrode lead-out hole 222, it is convenient to realize the electrical connection between the fourth terminal portion 41 and the second tab 13.

[0367] 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 outer shell 20, the fifth terminal portion 42 is located inside the outer shell 20 and is electrically connected to the second tab 13, at least part of the sixth terminal portion 43 is received 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.

[0368] 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.

[0369] The sixth terminal portion 43 and the fifth terminal portion 42 can be an integrally formed structure. Alternatively, the sixth terminal portion 43 and the fifth terminal portion 42 can also be independently formed and fixedly connected by welding, clamping, bonding or other means.

[0370] The sixth terminal portion 43 can be one or multiple.

[0371] The materials of the sixth terminal portion 43 and the fourth terminal portion 41 can be the same or different.

[0372] 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 to form a second welding mark 80b. Alternatively, the fifth terminal portion 42 can also be connected to the second tab 13 through other conductive structures (such as a transition piece).

[0373] In some embodiments, the sixth terminal portion 43 and the fifth terminal portion 42 are an integrally formed structure, which can improve the connection strength between the sixth terminal portion 43 and the fifth terminal portion 42, reduce the resistance and enhance the overcurrent capacity.

[0374] 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 received in the second through hole 414 and connected to the fourth terminal portion 41.

[0375] Exemplarily, the second through hole 414 can be a hole with a constant diameter or a hole with a variable diameter. For example, the second through hole 414 can be a stepped hole.

[0376] One end of the sixth terminal portion 43 away from the second terminal portion 32 may extend beyond the second through hole 414 or may not extend beyond the second through hole 414.

[0377] During assembly, the sixth terminal portion 43 can be first passed through the second electrode lead-out hole 222 and the second through hole 414, and then the sixth terminal portion 43 can be connected to the fourth terminal portion 41. By providing the second through hole 414, the assembly process can be simplified.

[0378] In some embodiments, both the fourth terminal portion 41 and the fifth terminal portion 42 are flat plate-shaped. The sixth terminal portion 43 is columnar.

[0379] In some embodiments, the sixth terminal portion 43 is riveted to the fourth terminal portion 41.

[0380] In some embodiments, in the axial direction of the second electrode lead-out hole 222, one end of the sixth terminal portion 43 away from the fifth terminal portion 42 does not extend beyond the second through hole 414 to reduce the risk of the sixth terminal portion 43 interfering with the connection between the fourth terminal portion 41 and the second bus component 7b.

[0381] Optionally, the second electrode terminal 40 is disposed on the first wall portion 20a, and the axial direction of the second electrode lead-out hole 222 is parallel to the thickness direction Z of the first wall portion 20a.

[0382] In some embodiments, the second electrode terminal 40 includes one sixth terminal portion 43. The fourth terminal portion 41 and the fifth terminal portion 42 can have a relatively small area. Therefore, using one sixth terminal portion 43 can stably connect the fourth terminal portion 41 and the fifth terminal portion 42, thereby simplifying the structure of the second electrode terminal 40 and reducing the volume of the second electrode terminal 40.

[0383] In some embodiments, the first electrode terminal 30 is a positive terminal, and the second electrode terminal 40 is a negative terminal.

[0384] 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. Exemplarily, the base metal of the first terminal portion 31, the second terminal portion 32, and the third terminal portion 33 is aluminum. For example, the material of the first terminal portion 31 is aluminum or aluminum alloy, the material of the second terminal portion 32 is aluminum or aluminum alloy, and the material of the third terminal portion 33 is aluminum or aluminum alloy.

[0385] The base metal of the second terminal portion 32 is the same as the base metal of the first tab 12.

[0386] The fifth terminal portion 42 and the sixth terminal portion 43 include the same base metal. Exemplarily, the base metal of the fifth terminal portion 42 and the sixth terminal portion 43 is copper. For example, the material of the fifth terminal portion 42 is copper or copper alloy, and the material of the sixth terminal portion 43 is copper or copper alloy.

[0387] The base metal of the sixth terminal portion 43 is the same as the base metal of the second tab 13.

[0388] The fourth terminal portion 41 may 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 through the second plate 41f and the first plate 41e. As an example, the first plate 41e is provided with a groove, and the second plate 41f is received in the groove.

[0389] 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.

[0390] The base metal of the first plate 41e is the same as the base metal of the second bus bar member 7b, which is convenient for welding. The base metal of the first terminal portion 31 is the same as the base metal of the first bus bar member 7a, which is convenient for welding. The first bus bar member 7a and the second bus bar member 7b are made of the same material.

[0391] Compared with aluminum, copper has a smaller resistivity and a stronger heat conduction ability. Compared with the second tab 13, the first tab 12 generates heat more easily and the heat conducts outward more slowly; therefore, exchanging heat between the heat exchanger 9 and the first terminal portion 31 can improve the heat dissipation speed of the first tab 12 outward, reduce the temperature difference between the first tab 12 and the second tab 13, and improve the cycling performance of the battery cell 6.

[0392] 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 current-carrying 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.

[0393] 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.

[0394] Optionally, the area of the first welding mark 80a is larger than the area of the second welding mark 80b.

[0395] Optionally, the length of the first welding mark 80a is greater than the length of the second welding mark 80b.

[0396] In some embodiments, the projected area of the second terminal portion 32 in its own thickness direction is larger than the projected area of the fifth terminal portion 42 in its own thickness direction.

[0397] Compared with the fifth terminal portion 42, the second terminal portion 32 can have a larger current-carrying area, thereby reducing the heat generation of the second terminal portion 32.

[0398] The first terminal portion 31 has a larger area to achieve heat exchange with the heat exchange member 9. By setting the second terminal portion 32 to have a larger area, the strength difference 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 cell 6 is subjected to an external impact can be reduced, and the stability of fixing the first electrode terminal 30 to the first wall portion 20a can be improved.

[0399] As an example, the base metal of the second terminal portion 32 is aluminum, and the base metal of the fifth terminal portion 42 is copper. By increasing the area of the second terminal portion 32, the difference in current-carrying capacity between the second terminal portion 32 and the fifth terminal portion 42 can be reduced.

[0400] In some embodiments, the projected area of the second terminal portion 32 in its own thickness direction is 1.2 - 5 times the projected area of the fifth terminal portion 42 in its own thickness direction.

[0401] Optionally, the projected area of the second terminal portion 32 in its own thickness direction is 1.2 times, 1.5 times, 2 times, 2.5 times, 3 times, 3.5 times, 4 times, 4.5 times or 5 times the projected area of the fifth terminal portion 42 in its own thickness direction.

[0402] Optionally, the projected area of the second terminal portion 32 in its own thickness direction is 2 - 3 times the projected area of the fifth terminal portion 42 in its own thickness direction.

[0403] The embodiments of the present application can, to a certain extent, balance the current-carrying capacity of the first electrode terminal 30 and the current-carrying capacity of the second electrode terminal 40, and improve the cycling performance of the battery cell 6.

[0404] In some embodiments, the battery cell 6 can be charged at a charging rate of 2C - 6C.

[0405] In some embodiments, at room temperature, the charging time of the battery cell 6 from 10% SOC to 80% SOC is less than or equal to 10.5 minutes.

[0406] As an example, the room temperature can be an ambient temperature of 30°C.

[0407] SOC refers to the state of charge of the battery cell 6.

[0408] Exemplarily, 100% SOC and 0% SOC are defined as follows: The battery cell 6 is charged at a constant current rate of 0.33C to the upper limit voltage of battery charging, and then charged at a constant voltage until 0.05C, corresponding to the state of 100% SOC of the battery cell; the battery cell 6 is discharged at a constant current rate of 0.33C to the cut-off voltage, corresponding to the state of 0% SOC of the battery cell. Exemplarily, the upper limit voltage of battery charging and the cut-off voltage during discharge are marked on the packaging film of the battery cell.

[0409] Exemplarily, the charging time of the battery cell 6 from 10% SOC to 80% SOC is 10.5 min, 10 min, 9.5 min, 9 min, 8.5 min, 8 min, 7.5 min, 7 min, 6.5 min, 6 min, 5.5 min, 5 min or a range composed of any two of the above values.

[0410] In the embodiments of the present application, the battery cell 6 has a fast charging ability, which can save charging time and improve the user experience. During the fast charging process of the battery cell 6, the first terminal portion can exchange heat with the heat exchange member, thereby reducing the temperature rise of the battery cell 6 and reducing the risk of thermal runaway of the battery cell.

[0411] Figure 12 It is a schematic structural diagram of an end cover assembly provided for other embodiments of the present application.

[0412] Refer to Figure 12 , in some embodiments, the first main body portion 311 and the first thinning portion 312 are arranged along the first direction X, the dimension W21 of the first main body portion 311 along the second direction Y is smaller than the dimension 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 in pairs.

[0413] In the first direction X, the dimension of the first main body portion 311 can be greater than, equal to, or smaller than the dimension of the first thinning portion 312.

[0414] The first thinning portion 312 has a larger dimension in the second direction Y, so as to increase the exposed area of the first thinning portion 312, further improve the heat dissipation efficiency, and improve the cycling performance of the battery cell 6. The thickness of the first thinning portion 312 is small. Compared with increasing the dimension of the first main body portion 311 in the second direction Y, increasing the dimension of the first thinning portion 312 in the second direction Y has a smaller impact on the energy density of the battery cell.

[0415] In addition, the first thinning portion 312 has a larger dimension in the second direction Y, so as to 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 cycling performance of the battery cell 6.

[0416] In some embodiments, the first terminal portion 31 is provided with a first recess 313, and the first recess 313 is recessed with respect to the surface of the first main body portion 311 away from the first wall portion 20a.

[0417] In some embodiments, the dimension L22 of the first thinning portion 312 in the first direction X may be greater than the dimension L21 of the first main body portion 311 in the first direction X to further increase the heat exchange area.

[0418] In some embodiments, the dimension W22 of the first thinning portion 312 in the second direction Y is greater than the width W3 of the fourth terminal portion 41.

[0419] Optionally, the dimension W21 of the first main body portion 311 in the second direction Y is equal to the width W3 of the fourth terminal portion 41.

[0420] Figure 13 Schematic diagram of the end cap assembly of the battery cell provided in other embodiments of the present application.

[0421] In some embodiments, the first main body portion 311 and the first thinning portion 312 are arranged at intervals in the first direction X, and the first direction X is perpendicular to the thickness direction Z of the first wall portion 20a.

[0422] The first main body portion 311 and the first thinning portion 312 can be independently formed, which is beneficial to the processing and forming of parts, and can also get rid of the size limitation caused by manufacturing capacity limitations, provide a larger area of the first thinning portion 312, thereby improving the heat dissipation effect.

[0423] In some embodiments, the first main body portion 311 is connected to the second terminal portion through at least one third terminal portion 33, and the first thinning portion 312 is connected to the second terminal portion through at least one third terminal portion 33.

[0424] Two third terminal portions 33 can respectively fix the first main body portion 311 and the first thinning portion 312 to the first wall portion 20a to keep the relative positions of the first main body portion 311 and the first thinning portion 312 fixed.

[0425] Exemplarily, part of the heat of the first main body portion 311 can be conducted to the first thinning portion 312 and the heat exchanger 9 through the third terminal portion 33 and the second terminal portion, so as to dissipate heat quickly.

[0426] In some embodiments, the surface of the first main body portion 311 facing the first wall portion 20a is flush with the surface of the first thinning portion 312 facing the first wall portion 20a.

[0427] In some embodiments, the area of the first thinning portion 312 is larger than the area of the fourth terminal portion 41.

[0428] Figure 14 The structural schematic diagram of the end cover assembly of the battery cell provided in other embodiments of the present application; Figure 15 is Figure 14 the top view schematic diagram of the end cover assembly shown.

[0429] Referring to Figure 14 , in some embodiments, the second electrode terminal 40 includes a fourth terminal portion 41 located outside the housing 20, and the fourth terminal portion 41 is used to connect the second current collecting member of the battery and exchange heat with the heat exchanger.

[0430] During the cycling of the battery 2, both the first terminal portion 31 and the fourth terminal portion 41 can exchange heat with the heat exchanger, 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 cycling performance and cycling life of the battery cell 6, and reduce the risk of thermal runaway of the battery cell 6 during rapid charging. The second electrode terminal 40 is connected to the second tab, and the heat of the second tab can also be conducted to the heat exchanger through the fourth terminal portion 41, so as to reduce the temperature rise of the electrode assembly and improve the cycling performance and cycling life of the battery cell 6. The fourth terminal portion 41 can simultaneously function as heat dissipation and current transmission, which helps to shorten the heat transfer path between the heat source and the heat exchanger and improve the heat dissipation efficiency.

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

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

[0433] In some embodiments, the second electrode terminal 40 includes a fourth terminal portion 41 located outside the housing 20, and the fourth terminal portion 41 includes a second main body portion 411 and a second thinning portion 412, and the thickness of the second main body portion 411 is greater than the thickness of the second thinning portion 412.

[0434] In the first direction X, the size of the second main body portion 411 and the size of the second thinning portion 412 may be the same or different; in the second direction Y, the size of the second main body portion 411 and the size of the second thinning portion 412 may be the same or different.

[0435] The second main body portion 411 and the second thinning portion 412 may be connected or separated. Optionally, the second main body portion 411 and the second thinning portion 412 are directly connected.

[0436] The second main body portion 411 has a larger thickness than the second thinning portion 412, and it is not easily penetrated during welding with other components, thereby improving the reliability of the battery cell. Exemplarily, the second main body portion 411 can be used for welding with the second current collecting component. Since the second main body portion 411 has a larger thickness, the welding strength can be increased, the current-carrying capacity can be improved, and heat generation can be reduced. By providing the second thinning portion 412, the exposed area of the second electrode terminal 40 can be increased, thereby enhancing 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 thinning portion 412 has a smaller thickness, thereby reducing the impact of adding the second thinning portion 412 on the energy density of the battery cell 6.

[0437] In some embodiments, the second main body portion 411 is used for connecting with the second current collecting component 7b of the battery. As an example, the second current collecting component 7b is welded to the second main body portion 411; optionally, the second current collecting component 7b is laser welded to the second main body portion 411. The second main body portion 411 has a larger thickness and is not easily penetrated during welding.

[0438] In some embodiments, the second thinning portion 412 is used for heat exchange with the heat exchanger 9 of the battery.

[0439] The second thinning portion 412 can exchange heat with the heat exchanger 9 in contact or indirectly exchange heat with the heat exchanger 9 through other heat conduction structures.

[0440] During the cycle of the battery 2, current flows through the second current collecting component 7b and the fourth terminal portion 41, causing heat generation in the fourth terminal portion 41 and the second current collecting component 7b. The second thinning portion 412 can exchange heat with the heat exchanger 9, thereby enhancing 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 during rapid charging of the battery cell 6. The second electrode terminal 40 is connected to the second tab 13, and the heat of the second tab 13 can also be conducted to the heat exchanger 9 through the second thinning portion 412, thereby reducing the temperature rise of the electrode assembly 10 and improving the cycle performance and cycle life of the battery cell 6.

[0441] The second main body portion 411 and the second thinning portion 412 can respectively function to transmit current and dissipate heat.

[0442] The second busbar component 7b and the heat exchanger 9 act on different parts of the fourth terminal portion 41 respectively, which can reduce the risk of interference between the second busbar component 7b and the heat exchanger 9.

[0443] In some embodiments, the second electrode terminal 40 includes a plurality of sixth terminal portions 43 arranged at intervals. By providing the plurality of sixth terminal portions 43, the overcurrent capacity can be improved, heat generation can be reduced, the structural strength of the second electrode terminal 40 can be enhanced, and the connection stability between the second electrode terminal 40 and the housing 20 can be improved.

[0444] In some embodiments, there are a plurality of second electrode lead-out holes, and the plurality of second electrode lead-out holes are arranged in one-to-one correspondence with the plurality of sixth terminal portions 43.

[0445] In some embodiments, the second main body portion 411 is connected to the fifth terminal portion 42 through at least one sixth terminal portion 43, and the second thinning portion 412 is connected to the fifth terminal portion 42 through at least one sixth terminal portion 43.

[0446] In some embodiments, the second main body portion 411 is configured to at least partially overlap and connect with the second busbar component in the thickness direction Z of the first wall portion 20a, and the second thinning portion 412 is configured to at least partially overlap with the heat exchanger in the thickness direction Z.

[0447] In some embodiments, the second busbar component is disposed on a side of the second main body portion 411 away from the first wall portion 20a and is connected to the second main body portion 411.

[0448] In some embodiments, the heat exchanger is disposed on a side of the second thinning portion 412 away from the first wall portion 20a.

[0449] In some embodiments, the thickness of the second main body portion 411 is greater than or equal to 3 mm.

[0450] In some embodiments, the thickness of the second main body portion 411 is equal to the thickness of the first main body portion 311, and the thickness of the second thinning portion 412 is equal to the thickness of the first thinning portion 312.

[0451] In some embodiments, the ratio of the thickness of the second main body portion 411 to the thickness of the second thinning portion 412 is 1.2 - 3, and can be optionally 1.2, 1.5, 2, 2.5 or 3.

[0452] In some embodiments, the second main body portion 411 extends beyond the second thinning portion 412 in a direction away from the first wall portion 20a.

[0453] In some embodiments, a second recess 413 is provided on a side of the fourth terminal portion 41 away from the first wall portion 20a, and the second thinning portion 412 is the bottom wall of the second recess 413.

[0454] In some embodiments, the second bus component is laser welded to the second main body portion 411.

[0455] In some embodiments, the second recess 413 is located on one side of the second main body portion 411 along the first direction X. One end of the second recess 413 away from the second main body portion 411 along the first direction X may extend to the edge of the fourth terminal portion 41.

[0456] In some embodiments, along the second direction Y, the second recess 413 penetrates the fourth terminal portion 41.

[0457] In some embodiments, in the thickness direction Z of the first wall portion 20a, the depth of the second recess 413 is 0.1 mm - 2 mm.

[0458] In some embodiments, the depth of the second recess 413 is equal to the depth of the first recess 313.

[0459] In some embodiments, when observed in the thickness direction Z, the area of the second thinning portion 412 is larger than the area of the second main body portion 411. The thickness of the second thinning portion 412 is smaller. Compared with increasing the area of the second main body portion 411, increasing the area of the second thinning portion 412 has a smaller impact on the energy density of the battery cell. Increasing the second thinning portion 412 can increase the exposed area of the fourth terminal portion 41 and increase the heat dissipation efficiency.

[0460] In addition, increasing the area of the second thinning portion 412 can also make the heat exchange area between the fourth terminal portion 41 and the heat exchange member larger.

[0461] In some embodiments, the second main body portion 411 and the second thinning portion 412 are arranged along the first direction X, and the dimension of the second main body portion 411 along the second direction Y is less than or equal to the dimension of the second thinning portion 412 along the second direction Y. Optionally, the dimension of the second main body portion 411 along the second direction Y is less than the dimension of the second thinning portion 412 along the second direction Y.

[0462] In some embodiments, the dimension of the second main body portion 411 along the second direction Y is equal to the dimension of the first main body portion 311 along the second direction Y. The dimension of the second thinning portion 412 along the second direction Y is equal to the dimension of the first thinning portion 312 along the second direction Y.

[0463] In some embodiments, the second main body portion 411 and the second thinning portion 412 may be arranged continuously along the first direction X or may be arranged at intervals along the first direction X.

[0464] In some embodiments, the dimension of the second main body portion 411 along the first direction X is less than or equal to the dimension of the second thinning portion 412 along the second direction Y. Optionally, the dimension of the second main body portion 411 along the first direction X is less than the dimension of the second thinning portion 412 along the first direction X.

[0465] In some embodiments, the first electrode terminal 30 is a positive terminal, and the second electrode terminal 40 is a negative terminal. In the thickness direction Z of the first wall portion 20a, the projected area of the first thinning portion 312 is greater than or equal to the projected area of the second thinning portion 412, and the projected area of the first main body portion 311 is greater than or equal to the projected area of the second main body portion 411.

[0466] Optionally, 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 main body portion 311 is greater than the projected area of the second main body portion 411.

[0467] In some embodiments, in the first direction X, the dimension of the first thinning portion 312 is greater than the dimension of the second thinning portion 412.

[0468] In some embodiments, the second electrode terminal 40 is disposed on the first wall portion 20a. The surface of the second main body portion 411 away from the first wall portion 20a includes a third region, and the 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 bus component in the thickness direction Z. The fourth region is configured to overlap with the heat exchange member in the thickness direction Z.

[0469] As an example, the third region is disposed in contact with the second bus component.

[0470] As an example, in the thickness direction Z, the projection of the fourth region is located within the projection of the heat exchange member.

[0471] The third region and the fourth region may be directly connected or spaced apart.

[0472] In some embodiments, the area of the fourth region is greater than the area of 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.

[0473] In some embodiments, the first electrode terminal 30 is the positive terminal, and the second electrode terminal 40 is the negative terminal. The area of the second region 31b is larger than the area of the fourth region. Both the first tab and the first electrode terminal 30 are made of copper, while the second tab is made of copper and a part of the second electrode terminal 40 is made of copper. The first tab and the first electrode terminal 30 generate more heat. By setting the second region 31b to be larger than the fourth region, the heat exchange efficiency between the first electrode terminal 30 and the heat exchange member can be improved, and the temperature difference between the first tab and the second tab can be reduced.

[0474] In some embodiments, the first electrode terminal 30 is the positive terminal, and the second electrode terminal 40 is the negative terminal. (L2×W2) / (L3×W3) is 1.2 - 5, and can be optionally 2 - 3.

[0475] 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.

[0476] In some embodiments, the second electrode terminal 40 is disposed 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.

[0477] The first main body portion 311 and the second main body portion 411 are respectively disposed at both ends of the first wall portion 20a along the first direction X, which helps multiple battery cells 6 to be arranged in a group.

[0478] In addition, the first thinning portion 312 and the second thinning portion 412 are adjacent to each other along the first direction X. The same heat exchange member can exchange heat with the first thinning portion 312 and the second thinning portion 412 at the same time, thereby simplifying the structure of the battery.

[0479] In some embodiments, the first region 31a, the second region 31b, the fourth region, and the third region are sequentially spaced apart along the first direction X, and the first direction X is perpendicular to the thickness direction Z.

[0480] The second region 31b and the fourth region are adjacent to each other along the first direction X. The same heat exchange member can exchange heat with the second region 31b and the fourth region at the same time, thereby simplifying the structure of the battery.

[0481] Figure 16 This is a schematic structural diagram of the end - cover assembly of the battery cell provided in some other embodiments of the present application.

[0482] Refer to Figure 16 In some embodiments, the second main body portion 411 and the second thinning portion 412 may be spaced apart along the first direction X.

[0483] Optionally, the second main body portion 411 is connected to the fifth terminal portion 42 through a sixth terminal portion 43, and the second thinning portion 412 is connected to the fifth terminal portion 42 through a sixth terminal portion 43.

[0484] Optionally, both the second main body portion 411 and the second thinning portion 412 are copper-aluminum composite plates.

[0485] In some embodiments, the first thinning portion 312, the first main body portion 311, the second main body portion 411, and the second thinning portion 412 are arranged along the first direction X, and the first direction X is perpendicular to the thickness direction Z. The first main body portion 311 and the second main body portion 411 are arranged opposite to each other along the first direction X, which helps to arrange a plurality of battery cells 6 in a group.

[0486] When a plurality of battery cells 6 are arranged along the first direction X, the first thinning portion 312 of one battery cell 6 is adjacent to the second thinning portion 412 (or the first thinning portion 312) of another battery cell 6. The same heat exchange member can exchange heat with two battery cells 6 at the same time, thereby simplifying the structure of the battery.

[0487] In some embodiments, the second region 31b, the first region 31a, the third region, and the fourth region are sequentially arranged at intervals along the first direction X, and the first direction X is perpendicular to the thickness direction Z. When a plurality of battery cells 6 are arranged along the first direction X, the second region 31b of one battery cell 6 is adjacent to the fourth region (or the second region 31b) of another battery cell 6. The same heat exchange member can exchange heat with two battery cells 6 at the same time, thereby simplifying the structure of the battery 2.

[0488] Figure 17 It is a simplified schematic diagram of a battery cell provided in other embodiments of the present application.

[0489] Refer to Figure 17 , in some embodiments, the housing 20 includes a second wall portion 20b, the second wall portion 20b is arranged opposite to the first wall portion 20a, and the second electrode terminal 40 is arranged on the second wall portion 20b.

[0490] By arranging the first electrode terminal 30 and the second electrode terminal 40 on the first wall portion 20a and the second wall portion 20b respectively, the first terminal portion 31 can have a larger area, thereby improving the heat exchange efficiency and the over-current capacity, and improving the cycling performance of the battery cell 6.

[0491] By arranging the first electrode terminal 30 and the second electrode terminal 40 at opposite ends of the housing 20, the short-circuit risk can also be reduced.

[0492] In some embodiments, the first electrode terminal 30 includes a first main body portion 311 and a first thinning portion 312, and the first main body portion 311 and the first thinning portion 312 are arranged at intervals along the first direction X.

[0493] In some embodiments, the second electrode terminal 40 includes a second main body portion 411 and a second thinning portion 412, and the second main body portion 411 and the second thinning portion 412 are spaced apart along the first direction X.

[0494] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the first terminal portion 31 is S1, and the projected area of the first wall portion 20a is S3. S1 and S3 satisfy: 0.2 ≤ S1 / S3 ≤ 0.8; optionally, 0.3 ≤ S1 / S3 ≤ 0.5.

[0495] Setting S1 / S3 to be greater than or equal to 0.3 can make the first terminal portion 31 have a larger area, thereby improving the heat dissipation capacity and overcurrent capacity of the first electrode terminal 30 and improving the cycling 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 first terminal portion 31 on the energy density of the battery cell 6.

[0496] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the fourth terminal portion 41 is S2, and the projected area of the first wall portion 20a is S3. S2 and S3 satisfy: 0.2 ≤ S2 / S3 ≤ 0.8; optionally, 0.3 ≤ S2 / S3 ≤ 0.5.

[0497] Setting S2 / S3 to be greater than or equal to 0.3 can make the fourth terminal portion 41 have a larger area, thereby improving the heat dissipation capacity and overcurrent capacity of the second electrode terminal 40 and improving the cycling 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 fourth terminal portion 41 on the energy density of the battery cell 6.

[0498] In some embodiments, heat exchange members can be provided 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.

[0499] Figure 18 A cross-sectional view of the battery provided by some embodiments of the present application.

[0500] Refer to Figure 18 , in some embodiments, the battery 2 includes a battery cell 6, a first bus bar member 7a, and a heat exchange member 9. The first bus bar member 7a is connected to the first main body portion 311. At least a part of the heat exchange member 9 is located on the side of the first wall portion 20a away from the electrode assembly and exchanges heat with the first thinning portion 312.

[0501] In some embodiments, the battery 2 further includes a second current collecting member 7b, and the second current collecting member 7b is connected to the fourth terminal portion 41. Optionally, the second current collecting member 7b is connected to the second main body portion 411.

[0502] In some embodiments, at least a part of the first thinning portion 312 is located between the heat exchange member 9 and the first wall portion 20a in the thickness direction Z of the first wall portion 20a.

[0503] The heat exchange member 9 can exchange heat with the first thinning portion 312, thereby improving the heat dissipation efficiency of the battery cell 6 and improving the cycling performance of the battery cell 6.

[0504] In some embodiments, the battery 2 includes a box body 5, and the battery cell 6 and the first current collecting member 7a are accommodated in the box body 5.

[0505] In some embodiments, a plurality of battery cells 6 are accommodated in the box body 5.

[0506] In some embodiments, the heat exchange member 9 is disposed outside the box body 5, which can save the internal space of the box body 5 and improve the space utilization rate.

[0507] In some embodiments, the heat exchange member 9 exchanges heat with the first electrode terminal 30 and the second electrode terminal 40 through the box wall of the box body 5.

[0508] In some embodiments, the first thinning portion 312 of the box wall and the first electrode terminal 30 are bonded by an insulating thermal conductive adhesive 9a.

[0509] In some embodiments, the second thinning portion 412 of the box wall and the second electrode terminal 40 are bonded by an insulating thermal conductive adhesive 9a.

[0510] In some embodiments, a plurality of battery cells 6 are arranged along the first direction X.

[0511] In some embodiments, the heat exchange member 9 is a heat exchange tube extending along the second direction Y.

[0512] Exemplarily, in the thickness direction Z of the first wall portion 20a, one heat exchange tube at least partially overlaps with the first thinning portion 312 of one battery cell 6, and at least partially overlaps with the second thinning portion 412 of another battery cell 6.

[0513] According to some embodiments of the present application, the present application further provides an electrical device, including the battery of any one of the above embodiments, and the battery is used to provide electrical energy for the electrical device. The electrical device can be any of the aforementioned devices or systems using the battery.

[0514] Referring to Figures 3 - 8 and Figure 18, embodiments of the present application provide a battery cell 6, which includes a housing 20, an electrode assembly 10, a first electrode terminal 30, and a second electrode terminal 40.

[0515] The electrode assembly 10 is accommodated in the housing 20 and includes a first tab 12 and a second tab 13 with opposite polarities.

[0516] The housing 20 includes a first wall portion 20a, and the first wall portion 20a is provided with a first electrode lead-out hole 221 and a second electrode lead-out hole 222.

[0517] 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 is connected to the first tab 12, at least a part of the third terminal portion 33 is accommodated in the first electrode lead-out hole 221, and the third terminal portion 33 connects the second terminal portion 32 and the first terminal portion 31. In the thickness direction Z of the first wall portion 20a, a part of the first wall portion 20a is located between the first terminal portion 31 and the second terminal portion 32.

[0518] 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 is connected to the second tab 13, at least a part of the sixth terminal portion 43 is accommodated in the second electrode lead-out hole 222, and the sixth terminal portion 43 connects the fifth terminal portion 42 and the fourth terminal portion 41. In the thickness direction Z of the first wall portion 20a, a part of the first wall portion 20a is located between the fourth terminal portion 41 and the fifth terminal portion 42.

[0519] The first terminal portion 31 includes a first main body portion 311 and a first thinning portion 312 arranged along 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 recess 313, and the first thinning portion 312 is the bottom wall of the first recess 313. There are two third terminal portions 33, and the two third terminal portions 33 are respectively connected to the first main body portion 311 and the first thinning portion 312.

[0520] The fourth terminal portion 41 includes 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 side of the fourth terminal portion 41 away from the first wall portion 20a has a second recess 413, and the second thinning portion 412 is the bottom wall of the second recess 413. There are two sixth terminal portions 43, and the two sixth terminal portions 43 are respectively connected to the second main body portion 411 and the second thinning portion 412.

[0521] 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.

[0522] The first main body portion 311 is used for connecting to the first bus bar member 7a of the battery 2, and the second main body portion 411 is used for connecting to the second bus bar member 7b of the battery 2. The first thinning portion 312 and the second thinning portion 412 are used for heat exchange with the heat exchanger 9.

[0523] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments may be combined with each other.

[0524] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that: include: a housing including a first wall portion; An electrode assembly, contained in the housing, the electrode assembly comprising a first electrode tab; as well as The first electrode terminal is arranged on the first wall portion and electrically connected to the first electrode tab. The first electrode terminal includes a first terminal portion located outside the first wall portion. The first terminal portion includes a first main body portion and a first thinning portion. The thickness of the first main body portion is greater than the thickness of the first thinning portion.

2. The battery cell according to claim 1, characterized in that: The first main body portion exceeds the first thinned portion in a direction away from the first wall portion.

3. The battery cell according to claim 1, characterized in that: The first terminal portion has a first recessed portion on a side away from the first wall portion, and the first thinned portion is a bottom wall of the first recessed portion.

4. The battery cell according to claim 3, characterized in that: In the thickness direction of the first wall portion, the depth of the first recess is 0.1 mm-2 mm.

5. The battery cell according to claim 1, characterized in that: The first main body and the first thinning portion are arranged along a first direction, a size of the first main body along a second direction is smaller than a size of the first thinning portion along the second direction, and a thickness direction of the first wall portion, the first direction and the second direction are perpendicular to each other.

6. The battery cell according to claim 1, characterized in that: The first main body portion and the first thinned portion are spaced apart along a first direction, and the first direction is perpendicular to a thickness direction of the first wall portion.

7. The battery cell according to claim 1, characterized in that: The first main body portion and the first thinned portion are arranged along a first direction, and the first direction is perpendicular to a thickness direction of the first wall portion; In the first direction, a size of the first thinned portion is larger than a size of the first main body portion.

8. The battery cell according to claim 1, characterized in that: 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 electrode tab, at least a portion 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 located between the first terminal portion and the second terminal portion.

9. The battery cell according to claim 8, characterized in that: The second terminal portion and the third terminal portion are an integrally formed structure.

10. The battery cell according to claim 8, characterized in that: 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 along the thickness direction of the first wall portion; A portion of the third terminal portion is received in the first through hole and connected to the first terminal portion.

11. The battery cell according to claim 10, characterized in that: 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 according to claim 10, characterized in that: The first thinned portion is used to exchange heat with the heat exchange element of the battery; At least one of the third terminal portions is configured such that: the third terminal portion is connected to the first thinned portion and at least partially overlaps with the heat exchange member in the thickness direction.

13. The battery cell according to claim 8, characterized in that: At least one of the third terminal portions is directly connected to the first main body portion.

14. The battery cell according to claim 8, characterized in that: The first electrode terminal includes a plurality of third terminal portions arranged at intervals; The first main body portion is connected to the second terminal portion through at least one third terminal portion, and the first thinned portion is connected to the second terminal portion through at least one third terminal portion.

15. The battery cell according to claim 8, characterized in that: The first main body portion and the first thinned portion are arranged along a first direction, and the first direction is parallel to the length direction of the first wall portion; One end of the first main body away from the first thinned portion has a first edge, and one end of the first thinned portion away from the first main body has a second edge; The first main body and the first thinned portion are both provided with a first through hole, and the two third terminal portions are respectively passed through the two first through holes and are respectively connected to the first main body and the first thinned portion; In the first direction, the distance between the first edge and the axis of the first through hole close to the first edge is D1, the distance between the second edge and the axis of the first through hole close to the second edge is D2, and the distance between the axes of two first through holes is D3; D1 / D2 is 0.9-1.1, (D1+D2) / D3 is 0.9-1.

1.

16. The battery cell according to claim 8, characterized in that: A cross section of the third terminal portion perpendicular to a thickness direction of the first wall portion is circular, elliptical or racetrack-shaped.

17. The battery cell according to claim 8, characterized in that: The first electrode tab is welded to the second terminal portion to form a first weld mark.

18. The battery cell according to claim 17, characterized in that: The first thinned portion is used to exchange heat with the heat exchange element of the battery; The first weld mark is configured to at least partially overlap the heat exchange element in a thickness direction of the first wall portion.

19. The battery cell according to claim 8, characterized in that: In a thickness direction of the first wall portion, a projected area of ​​the first terminal portion is larger than a projected area of ​​the second terminal portion.

20. The battery cell according to claim 8, characterized in that: In the thickness direction of the first wall portion, a projection area of ​​the second terminal portion is 0.2-0.5 times a projection area of ​​the first wall portion.

21. The battery cell according to claim 1, characterized in that: In the thickness direction of the first wall portion, a projection area of ​​the first terminal portion is 0.2-0.5 times a projection area of ​​the first wall portion.

22. The battery cell according to any one of claims 1 to 21, characterized in that: The first main body is used to be connected to a first collector component of a battery, and the first thinned portion is used to exchange heat with a heat exchange component of the battery.

23. The battery cell according to claim 22, characterized in that: The first main body portion is configured to at least partially overlap and connect with the first collecting member in a thickness direction of the first wall portion, and the first thinned portion is configured to at least partially overlap with the heat exchange element in the thickness direction.

24. The battery cell according to claim 22, characterized in that: A surface of the first terminal portion away from the first wall portion is configured to be connected to the heat exchange element.

25. The battery cell according to claim 22, characterized in that: The surface of the first main body away from the first wall portion includes a first area, and the surface of the first thinned portion away from the first wall portion includes a second area; The first region is arranged to overlap and connect with the first flow collecting member in the thickness direction of the first wall portion, and the second region is arranged to overlap with the heat exchange element in the thickness direction.

26. The battery cell according to claim 25, characterized in that: The first area and the second area are spaced apart from each other.

27. The battery cell according to claim 25, characterized in that: The area of ​​the second region is greater than that of the first region.

28. The battery cell according to claim 25, characterized in that: A ratio of an area of ​​the first region to a projected area of ​​the first terminal portion along the thickness direction is greater than or equal to 1.5%.

29. The battery cell according to claim 25, characterized in that: A ratio of an area of ​​the second region to a projected area of ​​the first terminal portion along the thickness direction is greater than or equal to 10%.

30. The battery cell according to claim 1, characterized in that The electrode assembly further includes a second electrode tab, wherein the first electrode tab has opposite polarity to the second electrode tab; The battery cell further includes a second electrode terminal disposed on the housing, and the second electrode terminal is electrically connected to the second electrode tab.

31. The battery cell according to claim 30, characterized in that: The second electrode terminal includes a fourth terminal portion located outside the housing, the fourth terminal portion includes a second main body portion and a second thinned portion, and the thickness of the second main body portion is greater than the thickness of the second thinned portion.

32. The battery cell according to claim 31, characterized in that: The second main body is used to be connected to a second collector component of a battery, and the second thinned portion is used to exchange heat with a heat exchange component of the battery.

33. The battery cell according to claim 31, characterized in that The second electrode terminal is disposed on the first wall portion; The first thinning portion, the first main body portion, the second main body portion and the second thinning 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 thinning portion, the second thinning portion and the second main body portion are arranged along the first direction.

34. The battery cell according to claim 30, characterized in that The second electrode terminal includes a fourth terminal portion located outside the housing; A projection area of ​​the first terminal portion along its thickness direction is greater than a projection area of ​​the fourth terminal portion along its thickness direction.

35. The battery cell according to claim 34, characterized in that The projection area of ​​the first terminal portion along its thickness direction is 1.2-5 times the projection area of ​​the fourth terminal portion along its thickness direction.

36. The battery cell according to claim 30, characterized in that The housing is provided with a first electrode lead-out hole and a second electrode lead-out hole; The first electrode terminal further includes a second terminal portion and a third terminal portion, the second terminal portion is located inside the first wall portion and is electrically connected to the first electrode tab, at least a portion of the third terminal portion is accommodated in the first electrode lead-out hole, and the third terminal portion connects the second terminal portion and the first terminal portion; The second electrode terminal further includes a fourth terminal portion, a fifth terminal portion and a sixth terminal portion, wherein 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 electrode tab, and at least a portion 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 its thickness direction is larger than a projection area of ​​the fifth terminal portion along its thickness direction.

37. The battery cell according to claim 36, characterized in that: The projection area of ​​the second terminal portion along its thickness direction is 1.2-5 times the projection area of ​​the fifth terminal portion along its thickness direction.

38. The battery cell according to claim 30, characterized in that The second electrode terminal is disposed on the first wall portion, and the second electrode terminal includes a fourth terminal portion located outside the first wall portion; In the thickness direction of the first wall portion, the projection area of ​​the first terminal portion is S1, the projection area of ​​the fourth terminal portion is S2, and the projection area of ​​the first wall portion is S3; S1, S2 and S3 satisfy: 0.2≤(S1+S2) / S3≤0.

8.

39. The battery cell according to claim 30, characterized in that The housing includes a second wall portion, the second wall portion is arranged opposite to the first wall portion, and the second electrode terminal is arranged on the second wall portion; In the thickness direction of the first wall portion, the projection area of ​​the first terminal portion is S1, and the projection area of ​​the first wall portion is S3; S1 and S3 satisfy: 0.2≤S1 / S3≤0.

8.

40. The battery cell according to claim 1, characterized in that The housing includes a second wall portion, and the battery cell includes a pressure relief mechanism disposed on the second wall portion.

41. The battery cell according to claim 1, characterized in that The first electrode terminal is a positive electrode terminal, and the material of the first electrode terminal includes aluminum.

42. The battery cell according to claim 1, characterized in that The first wall portion is provided with an electrolyte injection hole.

43. The battery cell according to claim 1, characterized in that The housing comprises a shell and an end cover, the shell has an opening, and the end cover is connected to the shell and covers the opening; The end cover is the first wall portion.

44. A battery, characterized in that: include: A battery cell according to any one of claims 1 to 43; A first confluence component connected to the first main body; as well as A heat exchange member, at least a portion of which is located on a side of the first wall portion away from the electrode assembly and exchanges heat with the first thinned portion.

45. The battery according to claim 44, characterized in that In the thickness direction of the first wall portion, at least a portion of the first thinned portion is located between the heat exchange element and the first wall portion.

46. ​​The battery according to claim 44 or 45, characterized in that The battery also includes a box; The battery cells and the first collector are accommodated in the box body, and the heat exchange element is disposed outside the box body.

47. An electrical device, characterized in that: Comprising a battery according to any one of claims 44-46, the battery is used to provide electrical energy.

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