Battery cell, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device. The battery cell includes an electrode assembly, a housing, a positive terminal, and a negative terminal. The housing includes a first wall portion. The electrode assembly is contained in the shell and comprises a positive electrode lug and a negative electrode lug. The positive terminal is arranged on the first wall part and is electrically connected to the positive tab; the positive terminal comprises a first positive terminal part positioned on the outer side of the first wall part; the negative terminal is arranged on the shell and is electrically connected to the negative tab; the negative terminal comprises a first negative terminal part positioned on the outer side of the shell; the projection area of the first positive terminal portion in the thickness direction is larger than the projection area of the first negative terminal portion in the thickness direction.

Description

Technical Field

[0001] The present application relates to the field of battery technology, 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, electric vehicles, electric cars, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

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

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

[0005] In a first aspect, an embodiment of the present application provides a battery cell comprising an electrode assembly, a housing, a positive terminal, and a negative terminal. The housing comprises a first wall portion. The electrode assembly is housed within the housing, and the electrode assembly comprises a positive electrode tab and a negative electrode tab. The positive terminal is disposed on the first wall portion and electrically connected to the positive electrode tab, and the positive terminal comprises a first positive terminal portion located outside the first wall portion. The negative terminal is disposed on the housing and electrically connected to the negative electrode tab, and the negative terminal comprises a first negative terminal portion located outside the housing. The projected area of the first positive terminal portion along its thickness direction is greater than the projected area of the first negative terminal portion along its thickness direction.

[0006] During the cycle of a battery cell, the positive and negative tabs generate heat when current passes through them. Part of the heat from the positive tab can be dissipated outwards through the first positive terminal, and part of the heat from the negative tab can be dissipated outwards through the first negative terminal, thereby reducing the temperature rise of the positive and negative tabs. In an embodiment of the present application, the projected area of the first positive terminal along its thickness direction is larger than the projected area of the first negative terminal along its thickness direction. This allows the first positive terminal to have a larger exposed area, thereby improving the efficiency of heat dissipation from the first positive terminal, reducing the heat accumulated in the positive tab, reducing the temperature difference between the positive and negative tabs, and improving the cycle performance and cycle life of the battery cell.

[0007] In some embodiments, the first positive terminal portion is used to connect to the first busbar of the battery and exchange heat with the heat exchanger of the battery. The first positive terminal portion can exchange heat with the heat exchanger, thereby further reducing the temperature rise of the positive electrode tab, reducing the temperature difference between the positive electrode tab and the negative electrode tab, improving the heat dissipation capacity of the battery cell, improving the cycle performance and cycle life of the battery cell, and reducing the risk of thermal runaway of the battery cell during fast charging. In some embodiments, the first positive terminal portion includes a first part and a second part, the first part is used to connect to the first busbar, and the second part is used to exchange heat with the heat exchanger. The first busbar and the heat exchanger act on different parts of the first positive terminal portion, respectively, which can reduce the risk of interference between the first busbar and the heat exchanger.

[0008] In some embodiments, the first portion is configured to at least partially overlap and connect with the first conduit component in the thickness direction of the first wall portion, and the second portion is configured to at least partially overlap with the heat exchange component in the thickness direction of the first wall portion. The first portion and the first conduit component are arranged along the thickness direction, which can increase the connection strength and flow area between the first portion and the first conduit component, thereby reducing heat generation. The second portion and the heat exchange component are arranged in the thickness direction, which can increase the heat exchange area between the second portion and the heat exchange component and improve heat exchange efficiency. The first conduit component and the heat exchange component can share space in the thickness direction, thereby improving space utilization in the thickness direction and increasing the energy density of the battery.

[0009] In some embodiments, the thickness of the first portion is greater than that of the second portion. The first portion has a greater thickness than the second portion, making it less likely to melt through when welded to the first busbar, thereby improving the reliability of the battery cell. The second portion does not need to be welded to the first busbar and can be thinner, thereby reducing the volume and weight of the positive terminal and increasing the energy density of the battery cell.

[0010] In some embodiments, the first portion extends beyond the second portion in a direction away from the first wall. In the thickness direction of the first wall, the surface of the second portion away from the first wall is closer to the first wall than the surface of the second portion away from the first wall. This allows for more space to be reserved on the side of the second portion away from the first wall, facilitating the placement of heat exchange components and improving space utilization.

[0011] In some embodiments, the first positive terminal has a first recess on a side facing away from the first wall, with the second portion forming the bottom wall of the first recess. The provision of the first recess can reduce the volume and weight of the first positive terminal, increase the exposed area of the first positive terminal, and improve the heat dissipation capacity of the first positive terminal. The provision of the first recess also provides space for a heat exchange component, improving space utilization across the thickness of the first wall.

[0012] In some embodiments, the depth of the first recess in the thickness direction of the first wall portion is 0.1 mm to 2 mm. Limiting the depth of the first recess to 0.1 mm or greater provides more space for other components (e.g., heat exchangers), improving space utilization. Limiting the depth of the first recess to 2 mm or less reduces the loss of thermal conductivity caused by thinning the second portion, thereby balancing the heat exchange efficiency between the second portion and the heat exchanger.

[0013] In some embodiments, the first and second portions are arranged along a first direction, with the first portion having a smaller dimension along the second direction than the second portion, and the thickness of the first wall, the first direction, and the second direction being perpendicular to each other. The second portion has a larger dimension in the second direction, which increases the heat dissipation area of the second portion, reduces the temperature rise of the positive terminal and the positive tab, and improves the cycling performance of the battery cell. The second portion has a smaller thickness, and increasing the dimension of the second portion in the second direction has a smaller impact on the energy density of the battery cell than increasing the dimension of the first portion in the second direction.

[0014] In some embodiments, the first portion and the second portion are spaced apart along a first direction perpendicular to the thickness of the first wall. The first portion and the second portion can be formed independently, which facilitates part processing and molding, overcomes size limitations due to manufacturing capacity constraints, and provides a larger second portion, thereby improving heat dissipation.

[0015] In some embodiments, the first and second portions are arranged along a first direction perpendicular to the thickness of the first wall. In the first direction, the second portion is larger than the first portion. The second portion having a larger size in the first direction increases the heat exchange area between the second portion and the heat exchange element, improving heat exchange efficiency, reducing the temperature rise within the battery cell, and improving the battery cell's cycling performance. The second portion has a smaller thickness, and compared to increasing the size of the first portion, increasing the size of the second portion has a smaller impact on the weight of the battery cell.

[0016] In some embodiments, a surface of the first positive terminal away from the first wall is configured to be connected to a heat exchange element.

[0017] In some embodiments, the surface of the first positive terminal distal from the first wall portion includes a first region and a second region. The first region is configured to overlap and connect with the first converging member in the thickness direction of the first wall portion, and the second region is configured to overlap with the heat exchange element in the thickness direction of the first wall portion. The first converging member and the heat exchange element act on the first and second regions, respectively, thereby reducing the risk of interference between the first converging member and the heat exchange element and reducing overlap between the first converging member and the heat exchange element in the thickness direction, thereby improving space utilization.

[0018] In some embodiments, the first region and the second region are spaced apart to reduce the risk of interference between the first confluence component and the heat exchange element due to assembly errors.

[0019] In some embodiments, the area of the second region is larger than that of the first region. The larger area of the second region can improve the heat exchange efficiency between the heat exchange element and the first positive terminal, reduce the temperature rise of the first positive terminal, and improve the cycle performance and reliability of the battery cell.

[0020] In some embodiments, the ratio of the area of the first region to the projected area of the first positive terminal portion along the thickness direction of the first wall portion is greater than or equal to 1.5%, so that the first positive terminal portion and the first bus component have a larger connection area and higher connection strength, thereby improving the flow capacity between the first positive terminal portion and the first bus component, reducing heat generation, and lowering temperature rise.

[0021] In some embodiments, the ratio of the area of the second region to the projected area of the first positive terminal portion along the thickness direction of the first wall portion is greater than or equal to 10%, so that there is a larger heat exchange area between the first positive terminal portion and the heat exchange element, thereby improving the heat exchange efficiency between the first positive terminal portion and the heat exchange element, reducing the temperature rise of the first positive terminal portion and the temperature rise of the electrode assembly, and improving the cycle performance of the battery cell.

[0022] In some embodiments, the first wall portion is provided with a positive electrode lead-out hole. The positive terminal further includes a second positive electrode terminal portion and a third positive electrode terminal portion, wherein the second positive electrode terminal portion is located inside the first wall portion and is electrically connected to the positive electrode tab, and at least a portion of the third positive electrode terminal portion is accommodated in the positive electrode lead-out hole, and the third positive electrode terminal portion connects the second positive electrode terminal portion and the first positive electrode terminal portion. In the thickness direction of the first wall portion, a portion of the first wall portion is located between the first positive electrode terminal portion and the second positive electrode terminal portion.

[0023] In some embodiments, the second positive terminal portion and the third positive terminal portion are an integrally formed structure, which can improve the connection strength between the second positive terminal portion and the third positive terminal portion, reduce resistance, and improve current capacity.

[0024] In some embodiments, the first positive terminal has a first through hole extending through the first wall along a thickness direction thereof, and a portion of the third positive terminal is received in the first through hole and connected to the first positive terminal.

[0025] In some embodiments, in the thickness direction of the first wall portion, the end of the third positive terminal away from the second positive terminal portion does not extend beyond the first through hole, thereby reducing the risk of the third positive terminal portion interfering with the connection between the first positive terminal portion and other components.

[0026] In some embodiments, the first positive terminal is configured so that it at least partially overlaps with the heat exchange element of the battery in the thickness direction of the first wall. The third positive terminal is configured so that it does not overlap with the heat exchange element in the thickness direction of the first wall. Distancing the third positive terminal from the heat exchange element can reduce the risk of interference between the third positive terminal and the heat exchange element and improve the smoothness of the heat exchange interface between the first positive terminal and the heat exchange element.

[0027] In some embodiments, the first positive terminal includes a first edge and a second edge disposed opposite each other along a first direction parallel to the length of the first wall. In the first direction, the minimum spacing between the axis of the first through-hole and the first edge is equal to the minimum spacing between the axis of the first through-hole and the second edge. Centrally locating the first through-hole and the third positive terminal improves the structural strength of the positive terminal and reduces the risk of deformation of the first positive terminal.

[0028] In some embodiments, in a first direction, the minimum spacing between the axis of the first through-hole and the first edge is smaller than the minimum spacing between the axis of the first through-hole and the second edge. The portion of the first positive terminal located between the first edge and the first through-hole is used to connect to the first busbar of the battery, and the portion of the first positive terminal located between the second edge and the first through-hole is used to exchange heat with the heat exchange element of the battery. Designing the first through-hole off-center can reserve a larger area for heat exchange with the heat exchange element, thereby improving heat exchange efficiency. Embodiments of the present application can also reduce the distance between the third positive terminal and the first busbar, shortening the conductive path, reducing resistance, and reducing heat generation.

[0029] In some embodiments, the positive terminal includes a plurality of third positive terminal portions spaced apart from each other. Providing a plurality of third positive terminal portions can improve current flow capacity, reduce heat generation, increase the structural strength of the positive terminal, and enhance the stability of the connection between the positive terminal and the first wall portion.

[0030] In some embodiments, the first positive terminal portion includes a first portion and a second portion spaced apart along a first direction, the first direction being perpendicular to the thickness direction of the first wall portion. The first portion is connected to the second positive terminal portion via at least one third positive terminal portion, and the second portion is connected to the second positive terminal portion via at least one third positive terminal portion. The two third positive terminals can respectively secure the first portion and the second portion to the first wall portion to maintain a fixed relative position of the first portion and the second portion.

[0031] In some embodiments, the first positive terminal portion includes a first edge and a second edge arranged opposite to each other along a first direction, and the first direction is parallel to the length direction of the first wall portion. The first positive terminal portion is provided with two first through holes spaced apart along the first direction, and the two third positive terminals are respectively passed through the two first through holes and connected to the first positive terminal 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.

[0032] Observed from the thickness direction, the two third positive terminal portions are approximately symmetrically arranged, which can enhance the stability of the first positive terminal portion and improve the structural strength of the positive terminal.

[0033] In some embodiments, a cross-section of the third positive terminal portion perpendicular to the thickness direction of the first wall portion is circular, elliptical, or racetrack-shaped.

[0034] In some embodiments, the positive electrode tab is welded to the second positive terminal to form a first weld mark. Directly welding the positive electrode tab to the second positive terminal can shorten the conductive path between the positive electrode tab and the second positive terminal, reduce resistance, and reduce heat generation of the positive electrode tab and the second positive terminal.

[0035] In some embodiments, the first weld print is configured to at least partially overlap the battery's heat exchange element in the thickness direction of the first wall. When current passes through the first weld print, the first weld print generates heat. This embodiment of the present application can reduce the distance between the first weld print and the heat exchange element, improving the heat dissipation efficiency of the first weld print and reducing the temperature rise of the first weld print.

[0036] In some embodiments, the projected area of the first positive terminal is larger than the projected area of the second positive terminal in the thickness direction of the first wall. Compared to the second positive terminal, the first positive terminal can have a larger area, thereby improving the heat dissipation efficiency of the first positive terminal. Provided that the flow area meets the requirements, the second positive terminal can have a smaller area than the first positive terminal, thereby saving space within the housing and increasing the energy density of the battery cell.

[0037] In some embodiments, in the thickness direction of the first wall, the projected area of the second positive terminal is 0.2-0.5 times the projected area of the first wall. The ratio of the projected area of the second positive terminal to the projected area of the first wall is greater than or equal to 0.2, and the second positive terminal and the positive electrode tab can have a larger connection area and flow area, thereby reducing resistance, reducing heat generation of the second positive terminal and the positive electrode tab, and reducing the temperature rise of the battery cell. The ratio of the projected area of the second positive terminal to the projected area of the first wall 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 positive terminal and other components, and improve the reliability of the battery cell.

[0038] In some embodiments, the projected area of the first positive terminal is 0.2-0.5 times the projected area of the first wall in the thickness direction of the first wall. The ratio of the projected area of the first positive terminal to the projected area of the first wall is greater than or equal to 0.2, allowing the first positive terminal to have a larger exposed area for heat dissipation, thereby reducing the temperature rise of the first positive terminal and the positive electrode tab, and improving the cycling performance and reliability of the battery cell. The ratio of the projected area of the first positive terminal to the projected area of the first wall is less than or equal to 0.5, reserving installation space for other components of the battery cell.

[0039] In some embodiments, the first negative terminal portion is used to connect to the second busbar of the battery and exchange heat with the heat exchanger of the battery. During the cycle of the battery, both the first positive terminal portion and the first negative terminal portion can exchange heat with the heat exchanger, thereby further improving the heat dissipation capacity of the battery cell, reducing the temperature rise of the battery cell, improving the cycle performance and cycle life of the battery cell, and reducing the risk of thermal runaway of the battery cell during fast charging. The negative terminal is connected to the negative electrode tab, and the heat of the negative electrode tab can also be conducted to the heat exchanger through the first negative terminal portion, thereby reducing the temperature rise of the electrode assembly and improving the cycle performance and cycle life of the battery cell. The first negative terminal portion can simultaneously dissipate heat and transmit current, which helps to shorten the heat transfer path between the heat source and the heat exchanger and improve the heat dissipation efficiency.

[0040] In some embodiments, the negative terminal is disposed on the first wall portion. The surface of the first positive terminal portion distal to the first wall portion includes a first region and a second region, wherein the first region is configured to overlap and connect with the first current collector of the battery in the thickness direction of the first wall portion. The surface of the first negative terminal portion distal to the first wall portion includes a third region and a fourth region, wherein the third region is configured to overlap and connect with the second current collector in the thickness direction of the first wall portion. The second region and the fourth region are configured to overlap with the heat exchange element in the thickness direction of the first wall portion.

[0041] In some embodiments, the first region, the second region, the fourth region, and the third region are sequentially spaced apart along a first direction. The first direction is perpendicular to the thickness of the first wall portion. The second region and the fourth region are adjacently disposed along the first direction, and the same heat exchange element can simultaneously exchange heat with the second region and the fourth region, thereby simplifying the battery structure.

[0042] In some embodiments, the second region, the first region, the third region, and the fourth region are sequentially spaced apart along the first direction. When multiple battery cells are arranged along the first direction, the second region of one battery cell is adjacent to the fourth region (or the second region) of another battery cell. The same heat exchange element can simultaneously exchange heat with both battery cells, thereby simplifying the battery structure.

[0043] In some embodiments, the outer shell is provided with a positive electrode lead-out hole and a negative electrode lead-out hole. The positive terminal further includes a second positive terminal portion and a third positive terminal portion, the second positive terminal portion is located inside the first wall portion and is electrically connected to the positive electrode tab, at least a portion of the third positive terminal portion is accommodated in the positive electrode lead-out hole, and the third positive terminal portion is connected to the second positive terminal portion and the first positive terminal portion. The negative terminal further includes a second negative terminal portion and a third negative terminal portion, the second negative terminal portion is located inside the outer shell and is electrically connected to the negative electrode tab, at least a portion of the third negative terminal portion is accommodated in the negative electrode lead-out hole, and the third negative terminal portion is connected to the second negative terminal portion and the first negative terminal portion.

[0044] In some embodiments, the projected area of the second positive terminal along its thickness is larger than the projected area of the second negative terminal along its thickness. Compared to the second negative terminal, the second positive terminal can have a larger flow area, thereby reducing heat generation of the second positive terminal and the positive electrode tab, reducing the temperature difference between the positive and negative electrode tabs, and improving the cycling performance of the battery cell.

[0045] In some embodiments, the projected area of the first positive terminal portion along its own thickness direction is 1.2-5 times the projected area of the first negative terminal portion along its own thickness direction. Optionally, the projected area of the first positive terminal portion along its own thickness direction is 2-3 times the projected area of the first negative terminal portion along its own thickness direction.

[0046] The embodiment of the present application can make the first positive terminal portion have a larger exposed area and limit the difference between the heat dissipation area of the first positive terminal portion and the heat dissipation area of the first negative terminal portion, so as to improve the efficiency of heat dissipation to the outside of the first positive terminal portion and reduce the temperature difference between the positive electrode tab and the negative electrode tab.

[0047] In some embodiments, both the positive and negative terminals are provided on the first wall. In the thickness direction of the first wall, the projected area of the first positive terminal is S1, the projected area of the first negative terminal is S2, and the projected area of the first wall is S3. S1, S2, and S3 satisfy the following: 0.2 ≤ (S1 + S2) / S3 ≤ 0.8; alternatively, 0.3 ≤ (S1 + S2) / S3 ≤ 0.5.

[0048] Setting (S1+S2) / S3 to greater than or equal to 0.2 allows the first positive terminal and the first negative terminal to have larger areas, thereby improving the heat dissipation and flow capacity of the positive terminal and the negative terminal, and improving the cycle performance of the battery cell. Setting (S1+S2) / S3 to less than or equal to 0.8 reserves installation space for other components and maintains the distance between the first and second positive terminals, reducing the risk of short circuits.

[0049] In some embodiments, the housing includes a second wall portion, and the negative terminal is disposed on the second wall portion. In the thickness direction of the first wall portion, the projected area of the first positive terminal portion is S1, and the projected area of the first wall portion is S3. S1 and S3 satisfy the following conditions: 0.2 ≤ S1 / S3 ≤ 0.8; optionally, 0.3 ≤ S1 / S3 ≤ 0.5.

[0050] Setting S1 / S3 to greater than or equal to 0.3 allows the first positive terminal to have a larger area, thereby increasing the heat dissipation and current carrying capacity of the positive terminal and improving the cycling performance of the battery cell. Setting S1 / S3 to less than or equal to 0.8 allows for installation space for other components and reduces the impact of increasing the first positive terminal on the energy density of the battery cell.

[0051] In some embodiments, the positive electrode tab is made of aluminum, the negative electrode tab is made of copper, the positive terminal is made of aluminum or an aluminum alloy, and at least a portion of the negative terminal is made of copper or a copper alloy.

[0052] Compared to copper, aluminum has higher electrical and thermal resistance, and the positive electrode tab is more likely to experience a larger temperature rise than the negative electrode tab. This embodiment of the application utilizes differentiated designs for the first positive and negative electrode terminals to increase the heat dissipation area and capacity of the first positive terminal, thereby reducing the temperature difference between the positive and negative tabs and improving the cycle performance and cycle life of the battery cell.

[0053] In some embodiments, the negative terminal is disposed on the first wall portion. In a thickness direction of the first wall portion, the first positive terminal portion overlaps with a heat exchange element of the battery, and the first negative terminal portion does not overlap with the heat exchange element.

[0054] Compared to the first negative terminal, the first positive terminal is closer to the heat exchange element. This further improves the efficiency of heat dissipation from the first positive terminal, reduces heat accumulation in the positive electrode tab, and reduces the temperature difference between the positive and negative tabs, thereby improving the cycling performance and cycle life of the battery cell. Furthermore, if the heat exchange efficiency between the heat exchange element and the first positive terminal meets the requirements, the heat exchange element may not exchange heat with the first negative terminal. This reduces the size of the heat exchange element, easing its layout complexity and improving the battery's energy density.

[0055] 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. Positioning the pressure relief mechanism on the second wall portion allows for more space on the first wall portion to be reserved for mounting the positive terminal, thereby increasing the exposed area of the first positive terminal portion, improving the heat dissipation capability of the first positive terminal portion, reducing the temperature rise of the first positive terminal portion and the temperature rise of the positive electrode tab, and improving the cycle performance and cycle life of the battery cell.

[0056] 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.

[0057] In some embodiments, the housing includes a shell and an end cap. The shell has an opening, and the end cap is connected to the shell and covers the opening. The end cap is the first wall portion. Compared to the shell, the end cap is typically thicker. Positioning the positive terminal on the end cap can improve the connection strength between the positive terminal and the end cap, enhance the stability of the positive terminal, and reduce the risk of positive terminal displacement.

[0058] In a second aspect, embodiments of the present application provide a battery comprising a battery cell according to any embodiment of the first aspect, a first current collector, and a heat exchanger. The first current collector is connected to a first positive terminal. At least a portion of the heat exchanger is located on a side of the first wall facing away from the electrode assembly and exchanges heat with the first positive terminal.

[0059] In some embodiments, a portion of the first positive terminal is located between the heat exchange element and the first wall in the thickness direction of the first wall. The heat exchange element can exchange heat with the first positive terminal, thereby improving the heat dissipation efficiency of the battery cell and improving the cycle performance of the battery cell.

[0060] In some embodiments, the battery further comprises a housing. The battery cells and the first confluence member are housed within the housing. The heat exchange element is disposed outside the housing, thereby saving space within the housing and improving space utilization.

[0061] In a third aspect, an embodiment of the present application provides an electrical device, which includes a battery provided by any embodiment of the second aspect, and the battery is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0063] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0064] Figure 2 A schematic diagram of a battery provided in some embodiments of the present application;

[0065] Figure 3 A schematic diagram of a partial structure of a battery provided in some embodiments of the present application;

[0066] Figure 4 A partial cross-sectional schematic diagram of a battery provided in some embodiments of the present application;

[0067] Figure 5 A schematic diagram of the structure of a battery provided in some embodiments of the present application;

[0068] Figure 6 for Figure 5 An exploded schematic diagram of a battery cell is shown;

[0069] Figure 7 for Figure 4 An enlarged schematic diagram at box A;

[0070] Figure 8 for Figure 4 An enlarged schematic diagram at box B;

[0071] Figure 9 A schematic structural diagram of an end cap assembly of a battery cell provided in some embodiments of the present application;

[0072] Figure 10 for Figure 9 A schematic top view of the end cap assembly is shown;

[0073] Figure 11 for Figure 9 A bottom view of the end cap assembly is shown;

[0074] Figure 12 A schematic structural diagram of an end cap assembly provided in some other embodiments of the present application;

[0075] Figure 13 for Figure 12 A schematic top view of the end cap assembly is shown;

[0076] Figure 14 A schematic structural diagram of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0077] Figure 15 A schematic structural diagram of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0078] Figure 16 A schematic structural diagram of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0079] Figure 17 for Figure 16 A schematic cross-sectional view of the end cap assembly shown;

[0080] Figure 18 A schematic top view of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0081] Figure 19 A schematic structural diagram of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0082] Figure 20 A schematic structural diagram of an end cap assembly of a battery cell provided in some other embodiments of the present application;

[0083] Figure 21 A simplified schematic diagram of a battery cell provided in some other embodiments of the present application;

[0084] Figure 22 A schematic cross-sectional view of a battery provided in some embodiments of the present application.

[0085] In the drawings, the figures are not drawn to scale;

[0086] Description of reference numerals:

[0087] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Housing; 5a. First housing portion; 5b. Second housing portion; 6. Battery cell; 7. Converging member; 7a. First converging member; 7b. Second converging member; 8. Heat exchange plate; 9. Heat exchange element; 9a. Thermal adhesive;

[0088] 10. Electrode assembly; 11. Electrode body; 12. Positive electrode tab; 13. Negative electrode tab;

[0089] 20, housing; 20a, first wall; 20b, second wall; 21, housing; 22, end cap; 221, positive electrode lead-out hole; 222, negative electrode lead-out hole; 223, electrolyte injection hole;

[0090] 30. Positive terminal; 31. First positive terminal; 311. First portion; 312. Second portion; 313. First recess; 314. First through-hole; 31a. First region; 31b. Second region; 31c. First edge; 31d. Second edge; 32. Second positive terminal; 33. Third positive terminal;

[0091] 40. Negative terminal; 41. First negative terminal; 411. Third portion; 412. Fourth portion; 413. Second recess; 414. Second through-hole; 41a. Third region; 41b. Fourth region; 41c. Third edge; 41d. Fourth edge; 41e. First plate; 41f. Second plate; 42. Second negative terminal; 43. Third negative terminal;

[0092] 50. End cap assembly;

[0093] 60. Pressure relief mechanism;

[0094] 70, sealing sheet; 80a, first weld mark; 80b, second weld mark;

[0095] X, first direction; Y, second direction; Z, thickness direction. DETAILED DESCRIPTION

[0096] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0097] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only 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-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0098] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0099] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0100] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. 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 indicates that the related objects are in an "or" relationship.

[0101] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0102] " Range " disclosed in this application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be inclusive or exclusive of end values, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that the range of 60 to 110 and 80 to 120 is also expected. 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 can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In this application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, a numerical range of "0 to 5" indicates that all real numbers between "0 and 5" are listed herein, and "0 to 5" is merely an abbreviation for a combination of these values. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0103] The term "plurality" used in this application refers to two or more (including two).

[0104] Currently, market developments indicate that batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal, wind, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. As battery applications continue to expand, market demand is also growing.

[0105] A battery generally refers to a single physical module that includes multiple battery cells to provide higher voltage and capacity. A battery cell may be the smallest unit that makes up a battery.

[0106] A battery cell includes an electrode assembly, which is the component within the cell where the electrochemical reaction occurs. The electrode assembly includes positive and negative tabs, which transmit current during the battery cell's cycling. When current flows through the positive and negative tabs, they generate heat. Due to material, flow area, or other factors, the temperature of the positive tab may be higher than that of the negative tab. This can affect the temperature consistency of the electrode assembly, causing localized high temperatures in the electrode assembly and impacting the cycling performance and life of the battery cell.

[0107] In view of this, the present application provides a technical solution, which differentiates the exposed area of the positive terminal connected to the positive electrode tab and the exposed area of the negative terminal connected to the negative electrode tab, thereby reducing the temperature difference between the positive electrode tab and the negative electrode tab, and improving the cycle performance and cycle life of the battery cell.

[0108] The battery described in the embodiments of the present application is suitable for use in an electrical device that uses a battery. The electrical device may be a device that uses a battery as a power source or various energy storage systems that use a battery as an energy storage element. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, electric toys may include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft may include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0109] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0110] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application.

[0111] like Figure 1 As 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 to power the vehicle 1, for example, the battery 2 can be used as an operating power source for the vehicle 1.

[0112] 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, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0113] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve 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.

[0114] Figure 2 Schematic diagram of a battery provided for some embodiments of the present application.

[0115] Reference Figure 2 In some embodiments, the battery 2 includes a housing 5 and a plurality of battery cells 6 housed in the housing 5 .

[0116] The battery cell 6 may be a secondary battery cell. A secondary battery cell refers to a battery cell 6 that can be continuously used by activating active materials by charging after the battery cell 6 is discharged.

[0117] 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-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc.

[0118] As an example, the battery cell 6 may be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal battery cells. Polygonal battery cells are, for example, hexagonal battery cells.

[0119] The multiple battery cells 6 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection means that the multiple battery cells 6 are connected both in series and in parallel. The multiple battery cells 6 can be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 6 is housed in the housing 5. Of course, the multiple battery cells 6 can also be first connected in series, in parallel, or in a hybrid connection to form a battery module, and then the multiple battery modules are connected in series, in parallel, or in a hybrid connection to form an entire battery module and housed in the housing 5.

[0120] In some embodiments, the box 5 is used to accommodate the battery cells 6 , and the box 5 can have various structures.

[0121] In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other, and the first housing portion 5a and the second housing portion 5b together define a storage space for accommodating the battery cells 6. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a is a plate-like structure. The first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space. The first housing portion 5a and the second housing portion 5b may also each be a hollow structure with one end open, and the open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space. Of course, the first housing portion 5a and the second housing portion 5b may have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0122] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0123] In some embodiments, the box 5 can be used as a part of the chassis structure of the vehicle. For example, part of the box 5 can become at least a part of the floor of the vehicle, or part of the box 5 can become at least a part of the crossbeam and longitudinal beam of the vehicle.

[0124] In some embodiments, the battery 2 may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0125] Figure 3 Schematic diagram of a partial structure of a battery provided in some embodiments of the present application.

[0126] Reference Figure 3 In some embodiments, the battery 2 includes a plurality of battery cells 6 and a plurality of busbars 7 , and the plurality of busbars 7 electrically connect the plurality of battery cells 6 .

[0127] The plurality of busbar components 7 connect the plurality of battery cells 6 in series, in parallel, or in mixed series.

[0128] The plurality of confluence members 7 may have the same structure or different structures.

[0129] The flow collecting member 7 may be a single-layer structure or a multi-layer structure.

[0130] In some embodiments, the battery cells 6 include positive terminals 30 and negative terminals 40. As an example, the busbar 7 is connected to the positive terminal 30 of one battery cell 6 and the negative terminal 40 of another battery cell 6 to connect the two battery cells 6 in series. Alternatively, the busbar 7 is connected to the positive terminals 30 of two battery cells 6 to connect the two battery cells 6 in parallel.

[0131] In some embodiments, the busbar component 7 is welded to the positive terminal 30 or the negative terminal 40 .

[0132] In some embodiments, the current collecting component 7 has a multi-layer structure. For example, the current collecting component 7 has a multi-layer structure in its thickness direction. For example, the current collecting component 7 is bent to form a double-layer structure or a triple-layer structure.

[0133] Each layer of the bus component 7 can transmit current. Setting the bus component 7 as a multi-layer structure can increase the flow area of the bus component 7, reduce the heat generated by the bus component 7 during overcurrent, reduce the temperature rise of the battery cell 6, and improve the fast charging capability of the battery cell 6.

[0134] Provided that the flow area meets the requirements, the multi-layer structure of the busbar assembly 7 can reduce the thickness of each layer of the busbar assembly 7. The battery cells 6 expand during cycling, thereby stretching the layer of the busbar assembly 7 connected to the battery cells 6. The thinner layer of the busbar assembly 7 easily deforms to accommodate the expansion and deformation of the battery cells 6, thereby reducing the risk of rupture at the connection between the battery cells 6 and the busbar assembly 7 and improving the reliability of the battery 2.

[0135] In some embodiments, the battery 2 further includes a heat exchange plate 8 , which is used to exchange heat with the outer shell of the battery cell 6 .

[0136] The heat exchange plate 8 can exchange heat with the battery cell 6 during the cycle of the battery cell 6, thereby maintaining the battery cell 6 within a suitable temperature range, improving the cycle performance and cycle life of the battery cell 6, and reducing the risk of thermal runaway.

[0137] In some embodiments, the housing has two oppositely disposed large surfaces 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 along the thickness direction of the battery cell 6 and exchanges heat with the large surfaces of the battery cell 6.

[0138] The large surface is the largest surface on the outer surface of the housing. The large surface exchanges heat with the heat exchange plate 8 to improve heat exchange efficiency, thereby reducing the temperature rise of the battery cell 6 during fast charging, improving the cycle performance and cycle life of the battery cell 6, reducing the risk of thermal runaway, and improving reliability.

[0139] In some embodiments, heat exchange plates 8 are provided on both sides of the battery cell 6 , that is, the two large surfaces of the battery cell 6 exchange heat with two heat exchange plates 8 respectively.

[0140] In some embodiments, the battery 2 includes a plurality of heat exchange plates 8, which are arranged along the thickness direction of the battery cells 6. Battery cells 6 are disposed between adjacent heat exchange plates 8.

[0141] In some embodiments, the battery 2 further includes a heat exchange element 9 .

[0142] In some examples, the heat exchange element 9 is used to exchange heat with the positive terminal 30. In other examples, the heat exchange element 9 is used to exchange heat with the negative terminal 40. In some examples, the heat exchange element 9 exchanges heat with both the positive terminal 30 and the negative terminal 40.

[0143] As an example, the positive terminal 30 and the negative terminal 40 of the same battery cell 6 can both exchange heat with the heat exchange element 9, or only the positive terminal 30 can exchange heat with the heat exchange element 9 or only the negative terminal 40 can exchange heat with the heat exchange element 9.

[0144] As an example, for two adjacent battery cells 6, the heat exchange element 9 can simultaneously exchange heat with the positive terminals 30 of the two battery cells 6, or simultaneously exchange heat with the negative terminals 40 of the two battery cells 6, or simultaneously exchange heat with the positive terminal 30 of one battery cell 6 and the negative terminal 40 of another battery cell 6, or simultaneously exchange heat with the positive terminals 30 and negative terminals 40 of two battery cells 6.

[0145] As an example, the heat exchange element 9 may directly exchange heat with the electrode terminal (eg, the positive terminal and / or the negative terminal), or may indirectly exchange heat with the electrode terminal through other heat conducting elements.

[0146] As an example, the heat exchange element 9 may be located inside the box 5 or outside the box 5. Alternatively, the heat exchange element 9 may be located outside the box 5 and exchange heat with the electrode terminals through the box 5.

[0147] In some embodiments, the heat exchange element 9 includes a heat exchange tube. Exemplarily, the heat exchange tube is a flat tube.

[0148] In some embodiments, a flow channel is provided inside the heat exchange element 9; when the heat exchange medium flows through the flow channel, it exchanges heat with the electrode terminals through the heat exchange element 9.

[0149] Figure 4 A partial cross-sectional schematic diagram of a battery provided in some embodiments of the present application; Figure 5 A schematic diagram of the structure of a battery provided in some embodiments of the present application; Figure 6 for Figure 5 An exploded schematic diagram of a battery cell is shown; Figure 7 for Figure 4 An enlarged schematic diagram at box A; Figure 8 for Figure 4 An enlarged schematic diagram at box B; Figure 9 A schematic structural diagram of an end cap assembly of a battery cell provided in some embodiments of the present application; Figure 10 for Figure 9 A schematic top view of the end cap assembly is shown; Figure 11 for Figure 9 A bottom view of the end cap assembly is shown.

[0150] Reference Figures 4 to 11 In some embodiments, the battery cell 6 includes a housing 20 and an electrode assembly 10 , with at least a portion of the electrode assembly 10 housed within the housing 20 .

[0151] The housing 20 is a hollow structure, and its interior forms a space for accommodating the electrode assembly 10 and the electrolyte. 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 rectangular parallelepiped structure, a rectangular housing can be selected.

[0152] In some embodiments, the housing 20 includes a shell 21 and an end cover 22 , wherein the shell 21 has an opening, and the end cover 22 is connected to the shell 21 and covers the opening;

[0153] The housing 21 is a component used to cooperate with the end cover 22 to form an internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0154] The housing 21 and the end cap 22 may be separate components. For example, an opening may be provided on the housing 21 , and the end cap 22 may be placed over the opening to form an internal cavity of the battery cell 6 .

[0155] The housing 21 can have various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a 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 housing 21 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the present embodiment does not impose any particular limitation on this.

[0156] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit 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 a certain hardness and strength (e.g., copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.). In this way, the end cap 22 is less likely to deform when subjected to compression or collision, thereby providing the battery cell 6 with higher structural strength and improved reliability.

[0157] The end cover 22 is connected to the housing 21 by welding, bonding, clamping or other methods.

[0158] The housing 21 may be open at one end or at both ends. In some examples, the housing 21 may be open at one end, with one end cap 22 provided to cover the housing 21. In other examples, the housing 21 may be open at both ends, with two end caps 22 provided to cover the two openings of the housing 21, respectively.

[0159] The electrode assembly 10 is a component where electrochemical reactions occur in the battery cell 6. One or more electrode assemblies 10 may be contained in the housing 21.

[0160] In some embodiments, the electrode assembly 10 includes a positive electrode sheet and a negative electrode sheet. During the charge and discharge process of the battery cell 6, active ions (such as lithium ions) are inserted and removed back and forth between the positive electrode sheet and the negative electrode sheet.

[0161] In some embodiments, the electrode assembly 10 further includes a separator, which is disposed between the positive electrode sheet and the negative electrode sheet to prevent a short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0162] In some embodiments, the positive electrode sheet may include a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector. For example, the portion of the positive electrode current collector not disposed with the positive electrode film layer may serve as a positive electrode tab.

[0163] As an example, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive electrode current collector.

[0164] In some embodiments, the negative electrode sheet may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector. For example, a portion of the negative electrode current collector not provided with the negative electrode film layer may serve as a negative electrode tab.

[0165] In some embodiments, the electrode assembly 10 includes an electrode body 11 , a positive electrode tab 12 , and a negative electrode tab 13 , wherein the positive electrode tab 12 and the negative electrode tab 13 are extended from the electrode body 11 .

[0166] As an example, the positive electrode sheet includes a portion of the positive electrode current collector coated with a positive electrode film layer, a portion of the negative electrode current collector coated with a negative electrode film layer, a positive electrode film layer, a negative electrode film layer, and a separator to form an electrode body 11. The positive electrode tab 12 and the negative electrode tab 13 can be led out from the same end of the electrode body 11, or can be led out from both ends of the electrode body 11.

[0167] In some embodiments, the electrode assembly 10 is a wound structure in which the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0168] In some embodiments, the electrode assembly 10 is a laminated structure.

[0169] As an example, multiple positive electrode sheets and multiple negative electrode sheets can be provided respectively, and the multiple positive electrode sheets and the multiple negative electrode sheets can be alternately stacked.

[0170] As an example, a plurality of positive electrode sheets may be provided, and the negative electrode sheet may be folded to form a plurality of stacked folded segments, with a positive electrode sheet being sandwiched between adjacent folded segments.

[0171] As an example, both the positive electrode sheet and the negative electrode sheet are folded to form a plurality of stacked folded segments.

[0172] As an example, a plurality of separators may be provided, each of which is provided between any adjacent positive electrode sheets or negative electrode sheets.

[0173] As an example, the separator may be provided continuously, and may be provided between any adjacent positive electrode sheets or negative electrode sheets by folding or winding.

[0174] In some embodiments, the battery cell 6 includes a positive terminal 30 and a negative terminal 40 that are insulated from each other. The positive terminal 30 is electrically connected to the positive electrode tab 12 , and the negative terminal 40 is electrically connected to the negative electrode tab 13 .

[0175] The positive terminal 30 and the negative terminal 40 are used to be electrically connected to an external circuit to enable charging or discharging of the battery cell 6 .

[0176] As an example, the positive terminal 30 may be an independently formed component that is mounted on the housing 20. Alternatively, the positive terminal 30 may be a part of the housing 20.

[0177] As an example, the negative terminal 40 may be a separately formed component that is mounted on the housing 20. Alternatively, the negative terminal 40 may be a part of the housing 20.

[0178] In some embodiments, the positive terminal 30 and the negative terminal 40 are both disposed on the end cap 22. As an example, the end cap 22, the positive terminal 30, and the negative terminal 40 may be preassembled together and then assembled with the electrode assembly 10 and the case 21.

[0179] Illustratively, the battery cell 6 includes an end cap assembly 50, which includes an end cap 22, a positive terminal 30, and a negative terminal 40. Optionally, the positive terminal 30 and the negative terminal 40 are both insulated from the end cap 22. Optionally, the positive terminal 30 is riveted to the end cap 22, and the negative terminal 40 is riveted to the end cap 22.

[0180] In some embodiments, the battery cell 6 also includes a pressure relief mechanism 60. This mechanism significantly impacts the reliability of the battery cell 6. For example, short circuits, overcharging, and other conditions can cause thermal runaway within the battery cell 6, leading to a sudden increase in pressure. In this situation, activation of the pressure relief mechanism 60 releases the internal pressure, reducing the risk of explosion or fire in the battery cell 6.

[0181] Exemplarily, the pressure relief mechanism 60 is a component or element that is activated to release internal gas when the internal pressure or temperature of the battery cell 6 reaches a predetermined threshold. This threshold value varies depending on design requirements and may depend on the materials of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 6.

[0182] The pressure relief mechanism 60 may take the form of an explosion-proof valve, an air valve, a pressure relief valve, or a safety valve, and may specifically be a pressure-sensitive element or structure. Specifically, when the internal pressure of the battery cell 6 reaches a predetermined threshold, the pressure relief mechanism 60 actuates, or a weak area within the pressure relief mechanism 60 ruptures, thereby forming an opening or passage through which the internal pressure can be released. Alternatively, the pressure relief mechanism 60 may be a temperature-sensitive element or structure. Specifically, when the internal temperature of the battery cell 6 reaches a predetermined threshold, the pressure relief mechanism 60 actuates, thereby forming an opening or passage through which the internal pressure can be released.

[0183] When the battery cell 6 thermally runs away, the emissions from the battery cell 6 include but are not limited to: electrolyte, dissolved or split positive and negative electrodes, fragments of the separator, high-temperature and high-pressure gas generated by the reaction, flames, etc.

[0184] In some embodiments, the pressure relief mechanism 60 is disposed on the housing 20. For example, the pressure relief mechanism 60 can be disposed on the housing 21 or on the end cover 22.

[0185] In some embodiments, the present application provides a battery cell 6, which includes an electrode assembly 10, a shell 20, a positive terminal 30 and a negative terminal 40. The shell 20 includes a first wall portion 20a. The electrode assembly 10 is accommodated in the shell 20, and the electrode assembly 10 includes a positive electrode tab 12 and a negative electrode tab 13. The positive terminal 30 is arranged on the first wall portion 20a and is electrically connected to the positive electrode tab 12. The positive terminal 30 includes a first positive terminal portion 31 located outside the first wall portion 20a. The negative terminal 40 is arranged on the shell 20 and is electrically connected to the negative electrode tab 13. The negative terminal 40 includes a first negative terminal portion 41 located outside the shell 20. The projected area of the first positive terminal portion 31 along its own thickness direction is larger than the projected area of the first negative terminal portion 41 along its own thickness direction.

[0186] The first wall portion 20a may be the end cap 22 or a wall of the housing 21. The negative electrode terminal 40 may be provided on the first wall portion 20a or on another wall portion of the housing 20 (the second wall portion 20b).

[0187] The positive terminal 30 and the positive electrode tab 12 can be directly connected or indirectly connected through other conductive structures. The negative terminal 40 and the positive electrode tab 13 can be directly connected or indirectly connected through other conductive structures.

[0188] There may be one or more positive electrode terminals 30 , and there may be one or more negative electrode terminals 40 .

[0189] As an example, in the thickness direction Z of the first wall portion 20 a , the first positive terminal portion 31 is located on a side of the end cover 22 that is away from the electrode body 11 .

[0190] As an example, the thickness direction of the first positive terminal portion 31 may be parallel to the thickness direction Z of the first wall portion 20 a .

[0191] The thickness direction of the first negative terminal portion 41 is related to the position of the negative terminal 40. For example, the first negative terminal portion 41 is provided on the first wall portion 20a, and the thickness direction of the first negative terminal portion 41 can be parallel to the thickness direction Z of the first wall portion 20a. For example, the first negative terminal portion 41 is provided on the second wall portion 20b, and the thickness direction of the first negative terminal portion 41 can be parallel to the thickness direction of the second wall portion 20b.

[0192] The material of the first negative pole terminal 41 may be the same as or different from the material of the first positive pole terminal 31 .

[0193] During the cycle of the battery cell 6, the positive electrode tab 12 and the negative electrode tab 13 generate heat when current passes through them. Part of the heat of the positive electrode tab 12 can be dissipated outward through the first positive terminal portion 31, and part of the heat of the negative electrode tab 13 can be dissipated outward through the first negative terminal portion 41, thereby reducing the temperature rise of the positive electrode tab 12 and the temperature rise of the negative electrode tab 13. In the embodiment of the present application, the projected area of the first positive terminal portion 31 along its own thickness direction is larger than the projected area of the first negative terminal portion 41 along its own thickness direction. This allows the first positive terminal portion 31 to have a larger exposed area, thereby improving the efficiency of the first positive terminal portion 31 in dissipating heat outward, reducing the heat accumulated in the positive electrode tab 12, reducing the temperature difference between the positive electrode tab 12 and the negative electrode tab 13, and improving the cycle performance and cycle life of the battery cell 6.

[0194] In some embodiments, the first positive terminal 31 is used to connect to the first busbar 7 a of the battery and exchange heat with the heat exchange element 9 of the battery.

[0195] The first positive terminal portion 31 can exchange heat with the heat exchange element 9, thereby further reducing the temperature rise of the positive electrode tab 12, reducing the temperature difference between the positive electrode tab 12 and the negative electrode tab 13, improving the heat dissipation capacity of the battery cell 6, improving the cycle performance and cycle life of the battery cell 6, and reducing the risk of thermal runaway of the battery cell 6 during fast charging.

[0196] During the battery 2 cycle, current flows through the first current collector 7a and the first positive terminal 31, causing the first positive terminal 31 and the first current collector 7a to generate heat. Exchanging heat between the first positive terminal 31 and the heat exchanger 9 helps shorten the heat transfer path between the heat source and the heat exchanger 9, thereby improving heat dissipation efficiency.

[0197] In some embodiments, in the thickness direction Z of the first wall portion 20 a , the distance between the heat exchange element 9 and the positive terminal 30 is smaller than the distance between the heat exchange plate 8 and the positive terminal 30 .

[0198] In some embodiments, the heat exchange plate 8 does not overlap with the positive terminal 30 in the thickness direction Z of the first wall portion 20 a .

[0199] In some embodiments, the housing 20 includes a shell 21 and an end cover 22. The shell 21 has an opening, and the end cover 22 is connected to the shell 21 and covers the opening. The end cover 22 is a first wall portion 20a.

[0200] Compared with the shell 21, the end cover 22 usually has a larger thickness; setting the positive terminal 30 on the end cover 22 can improve the connection strength between the positive terminal 30 and the end cover 22, enhance the stability of the positive terminal 30, and reduce the risk of displacement of the positive terminal 30.

[0201] During the production of the battery cell 6, the positive terminal 30 and the end cap 22 can be pre-assembled and then assembled with the housing 21, the electrode assembly 10 and other components. The positive terminal 30 and the end cap 22 are integrally produced, which can simplify the assembly process.

[0202] In some embodiments, the first wall portion 20 a is provided with an electrolyte injection hole 223 . During the production process of the battery cell 6 , electrolyte can be injected into the housing 20 through the electrolyte injection hole 223 .

[0203] After the processes related to the electrolyte injection hole 223 are completed, a sealing sheet 70 may be installed on the first wall portion 20 a to seal the electrolyte injection hole 223 .

[0204] In some embodiments, the positive terminal 30 is directly connected to the positive electrode tab 12. Alternatively, the positive terminal 30 is welded to the positive electrode tab 12.

[0205] Directly connecting the positive terminal 30 to the positive tab 12 not only eliminates the need for conventional adapters, but also shortens the conductive path, reduces resistance, and reduces heat generation. Furthermore, directly connecting the positive terminal 30 to the positive tab 12 shortens the heat transfer path between the positive tab 12 and the heat exchanger 9, improving heat dissipation and reducing the temperature rise of the positive tab 12.

[0206] In some embodiments, the negative terminal 40 is directly connected to the negative electrode tab 13. Alternatively, the negative terminal 40 is welded to the negative electrode tab 13. Directly connecting the negative terminal 40 to the negative electrode tab 13 not only saves the traditional adapter plate, but also shortens the conductive path and heat transfer path between the negative electrode tab 13 and the first negative terminal portion 41, thereby reducing resistance, heat generation, and lowering the temperature rise of the negative electrode tab 13.

[0207] In some embodiments, the negative terminal 40 may or may not exchange heat with the heat exchange element 9 .

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

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

[0210] As an example, two adjacent battery cells 6 are connected in series through a busbar component 7, which is connected to the positive terminal 30 of one battery cell 6 and the negative terminal 40 of the other battery cell 6; correspondingly, the busbar component 7 is a first busbar component 7a for one battery cell 6 and a second busbar component 7b for the other battery cell 6.

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

[0212] The second wall portion 20b may be a wall portion provided opposite to the first wall portion 20a, or may be a wall portion directly connected to the first wall portion 20a.

[0213] By setting 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 positive terminal 30, so that the first positive terminal portion 31 can have a larger exposed area, thereby improving the heat dissipation capacity of the first positive terminal portion 31, reducing the temperature rise of the first positive terminal portion 31 and the temperature rise of the positive electrode tab 12, and improving the cycle performance and cycle life of the battery cell 6.

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

[0215] As an example, the second wall portion 20 b is a bottom wall of the housing 21 .

[0216] In some embodiments, the positive electrode tab 12 is made of aluminum, the negative electrode tab 13 is made of copper, the positive electrode terminal 30 is made of aluminum or an aluminum alloy, and at least a portion of the negative electrode terminal 40 is made of copper or a copper alloy.

[0217] Compared to copper, aluminum has higher electrical and thermal resistances, and the positive electrode tab 12 is more susceptible to a greater temperature rise than the negative electrode tab 13. In this embodiment of the present application, the first positive terminal 31 and the first negative terminal 41 are designed differently to increase the heat dissipation area and heat dissipation capacity of the first positive terminal 31, thereby reducing the temperature difference between the positive electrode tab 12 and the negative electrode tab 13, and improving the cycle performance and cycle life of the battery cell 6.

[0218] In addition, exchanging heat between the heat exchange element 9 and the first positive terminal 31 can further improve the efficiency of heat dissipation of the positive electrode tab 12 and reduce the temperature difference between the positive electrode tab 12 and the negative electrode tab 13.

[0219] In some embodiments, a projection of the first positive terminal portion 31 along the thickness direction Z is substantially rectangular.

[0220] In some embodiments, the first positive terminal 31 includes a first portion 311 and a second portion 312 . The first portion 311 is used to connect to the first confluence component 7 a , and the second portion 312 is used to exchange heat with the heat exchange element 9 .

[0221] The thickness of the first portion 311 and the thickness of the second portion 312 may be the same or different.

[0222] In the first direction X, the size of the first portion 311 and the size of the second portion 312 may be the same or different; in the second direction Y, the size of the first portion 311 and the size of the second portion 312 may be the same or different.

[0223] As an example, the first direction X, the second direction Y, and the thickness direction Z of the first wall portion 20 a are perpendicular to each other.

[0224] As an example, the first direction X is parallel to the length direction of the first wall portion 20 a , and the second direction Y is parallel to the width direction of the first wall portion 20 a .

[0225] The first part 311 and the second part 312 can be connected or separated. Optionally, the first part 311 and the second part 312 are directly connected.

[0226] In the embodiment of the present application, the first converging component 7a and the heat exchange component 9 act on different parts of the first positive terminal portion 31 respectively, which can reduce the risk of interference between the first converging component 7a and the heat exchange component 9.

[0227] In some embodiments, the first portion 311 is configured to at least partially overlap and connect with the first conduit component 7a in the thickness direction Z of the first wall portion 20a, and the second portion 312 is configured to at least partially overlap with the heat exchange element 9 in the thickness direction Z of the first wall portion 20a.

[0228] The first portion 311 and the first converging member 7a are arranged along the thickness direction Z, which increases the connection strength and flow area between the first portion 311 and the first converging member 7a, thereby reducing heat generation. The second portion 312 and the heat exchange element 9 are arranged along the thickness direction Z, which increases the heat exchange area between the second portion 312 and the heat exchange element 9 and improves heat exchange efficiency. The first converging member 7a and the heat exchange element 9 can share space in the thickness direction Z, thereby improving space utilization in the thickness direction Z and increasing the energy density of the battery 2.

[0229] In some embodiments, the first conduit component 7 a is disposed on a side of the first portion 311 away from the first wall portion 20 a and is connected to the first portion 311 .

[0230] In some embodiments, the heat exchange element 9 is disposed on a side of the second portion 312 away from the first wall portion 20 a .

[0231] In some embodiments, the thickness t1 of the first portion 311 is greater than the thickness t2 of the second portion 312 .

[0232] For example, in the thickness direction Z of the first wall portion 20 a , the surface of the first portion 311 away from the first wall portion 20 a and the surface of the second portion 312 away from the first wall portion 20 a may be flush or may not be flush.

[0233] The first portion 311 has a greater thickness than the second portion 312. This makes the first portion 311 less likely to melt through when welded to the first busbar 7a, thereby improving the reliability of the battery cell 6. The second portion 312 does not need to be welded to the first busbar 7a and can have a smaller thickness, thereby reducing the volume and weight of the positive terminal 30 and increasing the energy density of the battery cell 6.

[0234] In some embodiments, the thickness of the first portion 311 is greater than or equal to 3 mm.

[0235] In some embodiments, the ratio of the thickness of the first portion 311 to the thickness of the second portion 312 is 1.2 to 3. Alternatively, t1 / t2 is 1.2, 1.5, 2, 2.5, or 3.

[0236] In some embodiments, the first portion 311 extends beyond the second portion 312 in a direction away from the first wall portion 20 a .

[0237] In the thickness direction Z of the first wall portion 20a, the surface of the second portion 312 away from the first wall portion 20a is closer to the first wall portion 20a than the surface of the second portion 312 away from the first wall portion 20a, thereby reserving more space on the side of the second portion 312 away from the first wall portion 20a to facilitate the arrangement of the heat exchange component 9 and improve space utilization.

[0238] In some embodiments, a side of the first positive terminal 31 away from the first wall 20 a has a first recess 313 , and the second portion 312 is a bottom wall of the first recess 313 .

[0239] The provision of the first recess 313 can reduce the volume and weight of the first positive terminal 31, increase the exposed area of the first positive terminal 31, and improve the heat dissipation capacity of the first positive terminal 31. The provision of the first recess 313 can also provide space for the heat exchange element 9, thereby improving the space utilization in the thickness direction Z of the first wall portion 20a.

[0240] In some embodiments, the first busbar 7 a is laser welded to the first portion 311 .

[0241] In some embodiments, the first recess 313 is located on one side of the first portion 311 along the first direction X. The end of the first recess 313 away from the first portion 311 along the first direction X may extend to the edge of the first positive terminal 31; alternatively, the end of the first recess 313 away from the first portion 311 along the first direction X may not extend to the edge of the first positive terminal 31, that is, the first positive terminal 31 may further include a third portion (not shown), the thickness of the third portion is greater than that of the second portion 312, the second portion 312 is connected between the first portion 311 and the third portion, and the first recess 313 is located between the first portion 311 and the third portion in the first direction X.

[0242] In some embodiments, along the second direction Y, the first recess 313 passes through the first positive terminal 31 .

[0243] In some embodiments, in the thickness direction Z of the first wall portion 20 a , a depth h of the first recess 313 is 0.1 mm-2 mm.

[0244] 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.

[0245] Limiting the depth of the first recess 313 to greater than or equal to 0.1 mm provides more space for other components (such as the heat exchanger 9), improving space utilization. Limiting the depth of the first recess 313 to less than or equal to 2 mm reduces the loss of thermal conductivity caused by the thinning of the second portion 312, thereby balancing the heat exchange efficiency between the second portion 312 and the heat exchanger 9 to a certain extent.

[0246] In some embodiments, when viewed in the thickness direction Z, the area of the second portion 312 is larger than the area of the first portion 311 , so that the heat exchange area between the first positive terminal 31 and the heat exchange element 9 can be larger.

[0247] In some embodiments, the first portion 311 and the second portion 312 are arranged along a first direction X, which is perpendicular to the thickness direction Z of the first wall portion 20 a. In the first direction X, a dimension L22 of the second portion 312 is greater than a dimension L21 of the first portion 311 .

[0248] The second portion 312 has a larger size than the first portion 311 in the first direction X, which can increase the heat exchange area between the second portion 312 and the heat exchange element 9, improve the heat exchange efficiency, reduce the temperature rise inside the battery cell 6, and improve the cycle performance of the battery cell 6.

[0249] The second portion 312 has a smaller thickness. Compared with the solution of increasing the size L21 of the first portion 311 , increasing the size L22 of the second portion 312 has less impact on the weight of the battery cell.

[0250] In some embodiments, the surface of the first positive terminal 31 away from the first wall 20 a is configured to be connected to the heat exchange element 9 .

[0251] As an example, the surface of the first positive terminal portion 31 away from the first wall portion 20 a may be a flat surface or a stepped surface.

[0252] The surface of the first positive terminal 31 away from the first wall 20a can be in contact with the heat exchanger 9, or can be indirectly connected to the heat exchanger 9 through other components. For example, the surface of the first positive terminal 31 away from the first wall 20a can be bonded to the heat exchanger 9 with thermal adhesive.

[0253] In some embodiments, the surface of the first positive terminal portion 31 away from the first wall portion 20a includes a first area 31a and a second area 31b, the first area 31a is configured to overlap and connect with the first convergence component 7a in the thickness direction Z of the first wall portion 20a, and the second area 31b is configured to overlap with the heat exchange element 9 in the thickness direction Z of the first wall portion 20a.

[0254] As an example, the first region 31 a is disposed in contact with the first collecting member 7 a .

[0255] As an example, in the thickness direction Z, the projection of the second region 31 b is located within the projection of the heat exchange element 9 .

[0256] The first region 31 a and the second region 31 b may be flush with each other or may be offset in the thickness direction Z of the first wall portion 20 a .

[0257] As an example, in Figure 10 In FIG, the first region 31 a and the second region 31 b are shown by oblique lines.

[0258] The first region 31a and the second region 31b may be directly connected or spaced apart.

[0259] The first converging component 7a and the heat exchange component 9 act on the first area 31a and the second area 31b respectively, which can reduce the risk of interference between the first converging component 7a and the heat exchange component 9, and reduce the overlap of the first converging component 7a and the heat exchange component 9 in the thickness direction Z, thereby improving space utilization.

[0260] In some embodiments, the first area 31 a and the second area 31 b are spaced apart to reduce the risk of interference between the first confluence component 7 a and the heat exchange element 9 due to assembly errors.

[0261] In some embodiments, the area of the second region 31b is larger than that of the first region 31a. The larger area of the second region 31b can improve the heat exchange efficiency between the heat exchange element 9 and the first positive terminal 31, reduce the temperature rise of the first positive terminal 31, and improve the cycle performance and reliability of the battery cell 6.

[0262] In some embodiments, the ratio of the area of the first region 31a to the projected area of the first positive terminal portion 31 along the thickness direction Z of the first wall portion 20a is greater than or equal to 1.5%, so that the first positive terminal portion 31 and the first bus component 7a have a larger connection area and higher connection strength, thereby improving the flow capacity between the first positive terminal portion 31 and the first bus component 7a, reducing heat generation, and lowering temperature rise.

[0263] As an example, the ratio of the area of the first region 31a to the projected area of the first positive terminal portion 31 along the thickness direction Z is 1.5%, 2%, 3%, 5%, 8%, 10%, 15%, 20%, 25% or 30%.

[0264] 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 , 25mm 2 , 30mm 2 , 35mm 2 , 40mm2 , 45mm 2 , 50mm 2 , 60mm 2 , 80mm 2 or 100mm 2 The first positive terminal portion 31 and the first current collecting component 7a have a larger connection area and higher connection strength, which improves the flow capacity between the first positive terminal portion 31 and the first current collecting component 7a, reduces heat generation, and lowers temperature rise.

[0265] In some embodiments, the ratio of the area of the second region 31b to the projected area of the first positive terminal portion 31 along the thickness direction Z of the first wall portion 20a is greater than or equal to 10%, so that there is a larger heat exchange area between the first positive terminal portion 31 and the heat exchange element 9, thereby improving the heat exchange efficiency between the first positive terminal portion 31 and the heat exchange element 9, reducing the temperature rise of the first positive terminal portion 31 and the temperature rise of the electrode assembly 10, and improving the cycle performance of the battery cell 6.

[0266] As an example, the ratio of the area of the second region 31b to the projected area of the first positive terminal portion 31 along the thickness direction Z is 10%, 12%, 14%, 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45% or 50%.

[0267] In some embodiments, the ratio of the area of the first region 31 a to the projected area of the first positive terminal 31 along the thickness direction Z is less than or equal to 70%, and may optionally be less than or equal to 40%.

[0268] In some embodiments, the first portion 311 includes a first region 31 a and the second portion 312 includes a second region 31 b .

[0269] In some embodiments, the first wall portion 20 a is provided with a positive electrode lead-out hole 221 .

[0270] As an example, the positive electrode lead-out hole 221 penetrates the first wall portion 20 a along the thickness direction Z of the first wall portion 20 a .

[0271] There may be one or more positive electrode lead-out holes 221 .

[0272] The positive electrode lead-out hole 221 may be a circular hole, a rectangular hole, an elliptical hole, a racetrack-shaped hole, or a hole of other shapes.

[0273] The positive electrode lead-out hole 221 is provided to facilitate electrical connection between the first positive electrode terminal 31 and the positive electrode tab 12 .

[0274] In some embodiments, the positive terminal 30 further includes a second positive terminal portion 32 and a third positive terminal portion 33. The second positive terminal portion 32 is located inside the first wall portion 20a and is electrically connected to the positive electrode tab 12. At least a portion of the third positive terminal portion 33 is accommodated in the positive electrode lead-out hole 221, and the third positive terminal portion 33 connects the second positive terminal portion 32 and the first positive terminal portion 31. In the thickness direction Z, a portion of the first wall portion 20a is located between the first positive terminal portion 31 and the second positive terminal portion 32.

[0275] The third positive terminal portion 33 and the first positive terminal portion 31 may be an integrally formed structure. Alternatively, the third positive terminal portion 33 and the first positive terminal portion 31 may also be formed independently and fixedly connected by welding, clamping, bonding or other means.

[0276] The third positive terminal portion 33 and the second positive terminal portion 32 may be an integrally formed structure. Alternatively, the third positive terminal portion 33 and the second positive terminal portion 32 may also be formed independently and fixedly connected by welding, clamping, bonding or other means.

[0277] There may be one or more third positive terminal portions 33 .

[0278] The third positive terminal portion 33 and the first positive terminal portion 31 may be made of the same material or different materials.

[0279] The second positive terminal portion 32 can be directly connected to the positive electrode tab 12, for example, the second positive terminal portion 32 is welded to the positive electrode tab 12. Alternatively, the second positive terminal portion 32 can also be connected to the positive electrode tab 12 through other conductive structures (such as an adapter).

[0280] The first wall portion 20a can limit the third positive terminal portion 33 in the radial direction of the positive electrode lead-out hole 221. The first positive terminal portion 31 and the second positive terminal portion 32 can clamp the first wall portion 20a from both sides, thereby achieving fixation in the thickness direction Z.

[0281] In some embodiments, the second positive terminal portion 32 and the third positive terminal portion 33 are an integrally formed structure, which can improve the connection strength between the second positive terminal portion 32 and the third positive terminal portion 33, reduce resistance, and improve current capacity.

[0282] Illustratively, the third positive terminal portion 33 protrudes from a surface of the second positive terminal portion 32 facing the first wall portion 20 a .

[0283] In some embodiments, the first positive terminal 31 has a first through hole 314 extending through the first wall 20 a in the thickness direction Z. A portion of the third positive terminal 33 is received in the first through hole 314 and connected to the first positive terminal 31 .

[0284] For example, the first through hole 314 may be a hole of constant diameter or a hole of variable diameter. For example, the first through hole 314 may be a stepped hole.

[0285] In the thickness direction Z, the end of the third positive terminal portion 33 away from the second positive terminal portion 32 may or may not exceed the first through hole 314 .

[0286] In the thickness direction Z, the end of the third positive terminal portion 33 away from the second positive terminal portion 32 may overlap with the first busbar member 7 a or may not overlap with the first busbar member 7 a.

[0287] In the thickness direction Z, the end of the third positive terminal portion 33 away from the second positive terminal portion 32 may overlap with the heat exchange element 9 or may not overlap with the heat exchange element 9 .

[0288] During assembly, the third positive terminal 33 may be first passed through the positive electrode lead-out hole 221 and the first through hole 314, and then connected to the first positive terminal 31. The provision of the first through hole 314 simplifies the assembly process.

[0289] In some embodiments, the first positive terminal portion 31 and the second positive terminal portion 32 are both in the shape of a flat plate, and the third positive terminal portion 33 is in the shape of a column.

[0290] In some embodiments, the third positive terminal 33 is riveted to the first positive terminal 31 .

[0291] In some embodiments, in the thickness direction Z of the first wall portion 20a, the end of the third positive terminal portion 33 away from the second positive terminal portion 32 does not exceed the first through hole 314, so as to reduce the risk of the third positive terminal portion 33 interfering with the connection between the first positive terminal portion 31 and other components (such as the first bus component 7a or the heat exchange component 9).

[0292] In some embodiments, the positive terminal 30 includes a plurality of third positive terminal portions 33 spaced apart from each other. The provision of the plurality of third positive terminal portions 33 can improve current flow capacity, reduce heat generation, increase the structural strength of the positive terminal 30, and enhance the stability of the connection between the positive terminal 30 and the first wall portion 20a.

[0293] In some embodiments, there are multiple positive electrode lead-out holes 221 , and the multiple positive electrode lead-out holes 221 are arranged in a one-to-one correspondence with the multiple third positive electrode terminal portions 33 .

[0294] In some embodiments, the first portion 311 is connected to the second positive terminal portion 32 through at least one third positive terminal portion 33 , and the second portion 312 is connected to the second positive terminal portion 32 through at least one third positive terminal portion 33 .

[0295] Connecting the first portion 311 to the third positive terminal 33 improves the stability of the first portion 311. When the battery cell 6 is subjected to an external impact, the third positive terminal 33 can limit the deformation of the first portion 311, thereby reducing the risk of failure in the connection between the first portion 311 and the first busbar 7a. Furthermore, connecting the first portion 311 to the third positive terminal 33 shortens the conductive path between the first busbar 7a and the positive electrode tab 12, reducing resistance.

[0296] Connecting the second portion 312 to the third positive terminal 33 allows the third positive terminal 33 to limit deformation of the second portion 312 when the battery cell 6 is subjected to an external impact, thereby reducing the stability of the heat exchange interface between the second portion 312 and the heat exchange element 9. Furthermore, connecting the second portion 312 to the third positive terminal 33 shortens the heat transfer path between the heat exchange element 9 and the positive electrode tab 12, reducing electrical resistance.

[0297] In some embodiments, the first positive terminal 31 includes a first edge 31c and a second edge 31d disposed opposite each other along a first direction X, parallel to the length of the first wall portion 20a. The first positive terminal 31 is provided with two first through holes 314 spaced apart along the first direction X. The two third positive terminals 33 are respectively disposed through the two first through holes 314 and connected to the first positive terminal 31. In the first direction X, the spacing between the first edge 31c and the axis of the first through hole 314 near the first edge 31c is D1, the spacing between the second edge 31d and the axis of the first through hole 314 near the second edge 31d is D2, and the spacing between the axes of the two first through holes 314 is D3. D1 / D2 is 0.9-1.1, and (D1+D2) / D3 is 0.9-1.1.

[0298] As an example, D1 / D2 is 0.9, 0.95, 1, 1.05 or 1.1.

[0299] As an example, (D1+D2) / D3 is 0.9, 0.95, 1, 1.05 or 1.1.

[0300] When viewed in the thickness direction Z, the two third positive terminal portions 33 are approximately symmetrically arranged, which can enhance the stability of the first positive terminal portion 31 and improve the structural strength of the positive terminal 30 .

[0301] In some embodiments, D1 = D2, optionally, D3 = 2× D1.

[0302] In some embodiments, a cross section of the third positive terminal portion 33 perpendicular to the thickness direction Z of the first wall portion 20 a is circular, elliptical, or racetrack-shaped.

[0303] In some examples, the third positive terminal portion 33 has a circular cross-section, and accordingly, the positive electrode lead-out hole 221 is a circular hole. The circular third positive terminal portion 33 is easy to process and form; the positive electrode lead-out hole 221 can be sealed with a circular sealing ring, which has uniform deformation and good sealing effect.

[0304] In other examples, the cross-section of the third positive terminal 33 is racetrack-shaped, and accordingly, the positive electrode lead-out hole 221 is also racetrack-shaped. A racetrack-shaped third positive terminal 33 can have a larger cross-sectional area than a circular third positive terminal 33, thereby improving the current flow capacity of the third positive terminal 33. Of course, a circular third positive terminal 33 is easier to process than a racetrack-shaped third positive terminal 33.

[0305] In still other examples, the cross-section of the third positive terminal portion 33 is elliptical.

[0306] In some embodiments, the positive electrode tab 12 is welded to the second positive terminal portion 32 and forms a first weld mark 80 a .

[0307] Directly welding the positive electrode tab 12 to the second positive terminal portion 32 can shorten the conductive path between the positive electrode tab 12 and the second positive terminal portion 32 , reduce resistance, and reduce heat generation of the positive electrode tab 12 and the second positive terminal portion 32 .

[0308] In some embodiments, the positive electrode tab 12 is connected to the second positive electrode terminal 32 by laser welding or ultrasonic welding.

[0309] In some embodiments, the first weld mark 80 a is configured to at least partially overlap with the heat exchange element 9 of the battery in the thickness direction Z of the first wall portion 20 a .

[0310] When current passes through the first weld mark 80a, the first weld mark 80a generates heat. The embodiment of the present application can reduce the distance between the first weld mark 80a and the heat exchange element 9, improve the heat dissipation efficiency of the first weld mark 80a, and reduce the temperature rise of the first weld mark 80a.

[0311] In some embodiments, in the thickness direction Z of the first wall portion 20 a , a projected area of the first positive terminal portion 31 is larger than a projected area of the second positive terminal portion 32 .

[0312] Compared with the second positive terminal 32, the first positive terminal 31 can have a larger area, which can improve the heat dissipation efficiency of the first positive terminal 31; on the premise that the flow area meets the requirements, the second positive terminal 32 can have an area smaller than the first positive terminal 31, thereby saving the internal space of the shell 20 and improving the energy density of the battery cell 6.

[0313] In some embodiments, in the thickness direction Z of the first wall portion 20 a , a projected area S1 of the first positive terminal portion 31 is 0.2-0.5 times a projected area S3 of the first wall portion 20 a .

[0314] Optionally, S1 / S3 is 0.2, 0.3, 0.4 or 0.5.

[0315] The ratio of the projected area of the first positive terminal 31 to the projected area of the first wall 20a is greater than or equal to 0.2. This allows the first positive terminal 31 to have a larger exposed area for heat dissipation, thereby reducing the temperature rise of the first positive terminal 30 and the positive electrode tab 12, and improving the cycling performance and reliability of the battery cell 6. The ratio of the projected area of the first positive terminal 31 to the projected area of the first wall 20a is less than or equal to 0.5, which reserves installation space for other components of the battery cell 6.

[0316] By limiting S1 / S3 to 0.2-0.5, the first positive terminal 31 can reserve a larger area for heat exchange with the heat exchange element 9, thereby improving the heat exchange efficiency.

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

[0318] It should be noted that the rectangle is not required to be an absolute rectangle. For example, the four corners of the rectangle can be set to be rounded.

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

[0320] The ratio of the projected area of the second positive terminal 32 to the projected area of the first wall 20a is greater than or equal to 0.2, allowing for a larger connection area and flow area between the second positive terminal 32 and the positive tab 12. This reduces resistance, reduces heat generation in the second positive terminal 32 and the positive tab 12, and reduces the temperature rise of the battery cell 6. The ratio of the projected area of the second positive terminal 32 to the projected area of the first wall 20a is less than or equal to 0.5, which reserves installation space for other components within the housing 20, reduces the risk of interference and short circuit between the second positive terminal 32 and other components, and improves the reliability of the battery cell 6.

[0321] In some embodiments, the first negative terminal portion 41 may be configured to be connected to the second bus bar 7 b .

[0322] Illustratively, the first negative terminal 41 may be disposed close to the heat exchange element 9 to exchange heat with the heat exchange element 9 ; alternatively, the first negative terminal 41 may be disposed away from the heat exchange element 9 to reduce heat exchange therewith.

[0323] In some embodiments, the projection area of the first positive terminal portion 31 along its own thickness direction is 1.2-5 times the projection area of the first negative terminal portion 41 along its own thickness direction. Optionally, the projection area of the first positive terminal portion 31 along its own thickness direction is 2-3 times the projection area of the first negative terminal portion 41 along its own thickness direction.

[0324] As an example, the projected area of the first positive terminal portion 31 along its thickness direction is equal to S1; the projected area of the first negative terminal portion 41 along its 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.

[0325] Limiting S1 / S2 to greater than or equal to 1.2 can provide a larger exposed area of the first positive terminal 31, thereby improving the efficiency of heat dissipation from the first positive terminal 31, reducing the heat accumulated in the positive electrode tab 12, and reducing the temperature difference between the positive electrode tab 12 and the negative electrode tab 13. Limiting S1 / S2 to less than or equal to 5 can also limit the difference between the heat dissipation area of the first positive terminal 31 and the heat dissipation area of the first negative terminal 41, thereby reducing the temperature difference between the positive electrode tab 12 and the negative electrode tab 13.

[0326] In addition, by limiting S1 / S2 to 1.2-5, the current capacity of the first positive terminal portion 31 and the first negative terminal portion 41 can be taken into consideration to a certain extent.

[0327] In some embodiments, the first negative terminal portion 41 is substantially rectangular, the length of the first negative terminal portion 41 is L3 , and the width of the first negative terminal portion 41 is W3 .

[0328] Optionally, (L2×W2) / (L3×W3) is 1.2-5, optionally 2-3.

[0329] In some embodiments, the positive terminal 30 and the negative terminal 40 are both provided on the first wall portion 20a. In the thickness direction Z of the first wall portion 20a, the projected area of the first positive terminal portion 31 is S1, the projected area of the first negative terminal portion 41 is S2, and the projected area of the first wall portion 20a is S3. S1, S2, and S3 satisfy the following: 0.2 ≤ (S1 + S2) / S3 ≤ 0.8.

[0330] Setting (S1+S2) / S3 to be greater than or equal to 0.2 allows the first positive terminal 31 and the first negative terminal 41 to have larger areas, thereby improving the heat dissipation and flow capacity of the positive terminal 30 and the negative terminal 40, and improving the cycle performance of the battery cell 6. Setting (S1+S2) / S3 to be less than or equal to 0.8 allows for space to be reserved for other components, maintains the distance between the first positive terminal 31 and the second positive terminal 32, and reduces the risk of short circuits.

[0331] Optionally, (S1+S2) / S3 is 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8.

[0332] Optionally, 0.3≤(S1+S2) / S3≤0.5.

[0333] Optionally, S1 / S2 is 1.5-3, optionally 2-3.

[0334] In some embodiments, the negative terminal 40 is disposed on the first wall portion 20 a . In the thickness direction Z of the first wall portion 20 a , the first positive terminal portion 31 overlaps with the heat exchange element 9 of the battery, while the first negative terminal portion 41 does not overlap with the heat exchange element 9 .

[0335] Compared with the first negative terminal 41, the distance between the first positive terminal 31 and the heat exchange element 9 is closer, which can further improve the efficiency of heat dissipation of the first positive terminal 31, reduce the heat accumulated in the positive electrode tab 12, reduce the temperature difference between the positive electrode tab 12 and the negative electrode tab 13, and improve the cycle performance and cycle life of the battery cell 6.

[0336] In addition, when the heat exchange efficiency between the heat exchange element 9 and the first positive terminal part 31 meets the requirements, the heat exchange element 9 may not exchange heat with the first negative terminal part 41. This can reduce the volume of the heat exchange element 9, reduce the difficulty of laying out the heat exchange element 9, and improve the energy density of the battery 2.

[0337] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the second portion 312 is larger than the projected area of the first negative terminal portion 41. Optionally, the projected area of the second portion 312 is 1.5-3 times the projected area of the first negative terminal portion 41.

[0338] In some embodiments, the housing 20 is provided with a negative electrode lead-out hole 222 .

[0339] The negative electrode lead-out hole 222 can be provided in the first wall portion 20a, the second wall portion 20b, or other wall portions of the housing 20. As an example, the negative electrode lead-out hole 222 is provided in the first wall portion 20a and penetrates the first wall portion 20a along the thickness direction Z of the first wall portion 20a.

[0340] There may be one or more negative electrode lead-out holes 222 .

[0341] The negative electrode lead-out hole 222 may be a circular hole, a rectangular hole, an elliptical hole, a racetrack-shaped hole, or a hole of other shapes.

[0342] The negative electrode lead-out hole 222 is provided to facilitate electrical connection between the first negative electrode terminal 41 and the negative electrode tab 13 .

[0343] In some embodiments, the negative terminal 40 also includes a first negative terminal portion 41, a second negative terminal portion 42 and a third negative terminal portion 43, the first negative terminal portion 41 is located on the outside of the outer shell 20, the second negative terminal portion 42 is located on the inside of the outer shell 20 and is electrically connected to the negative electrode tab 13, at least a portion of the third negative terminal portion 43 is accommodated in the negative electrode lead-out hole 222, and the third negative terminal portion 43 connects the second negative terminal portion 42 and the first negative terminal portion 41.

[0344] The third negative terminal portion 43 and the first negative terminal portion 41 may be integrally formed. Alternatively, the third negative terminal portion 43 and the first negative terminal portion 41 may be independently formed and fixedly connected by welding, clamping, bonding or other methods.

[0345] The third negative terminal portion 43 and the second negative terminal portion 42 may be integrally formed. Alternatively, the third negative terminal portion 43 and the second negative terminal portion 42 may be independently formed and fixedly connected by welding, clamping, bonding or other methods.

[0346] There may be one or more third negative electrode terminal portions 43 .

[0347] The third negative pole terminal 43 and the first negative pole terminal 41 may be made of the same material or different materials.

[0348] The second negative terminal portion 42 can be directly connected to the negative electrode tab 13. For example, the second negative terminal portion 42 is welded to the negative electrode tab 13 to form a second weld mark 80b. Alternatively, the second negative terminal portion 42 can also be connected to the negative electrode tab 13 through other conductive structures (such as an adapter).

[0349] In some embodiments, the third negative terminal portion 43 and the second negative terminal portion 42 are integrally formed, which can improve the connection strength between the third negative terminal portion 43 and the second negative terminal portion 42, reduce resistance, and improve current capacity.

[0350] In some embodiments, the first negative terminal 41 has a second through hole 414 extending through the first negative terminal 41 . A portion of the third negative terminal 43 is received in the second through hole 414 and connected to the first negative terminal 41 .

[0351] For example, the second through hole 414 may be a hole of constant diameter or a hole of variable diameter. For example, the second through hole 414 may be a stepped hole.

[0352] An end of the third negative terminal portion 43 away from the second positive terminal portion 32 may extend beyond the second through hole 414 or may not extend beyond the second through hole 414 .

[0353] During assembly, the third negative terminal 43 may be first passed through the negative electrode lead-out hole 222 and the second through hole 414, and then connected to the first negative terminal 41. The second through hole 414 may simplify the assembly process.

[0354] In some embodiments, the first negative terminal portion 41 and the second negative terminal portion 42 are both in the shape of a flat plate, and the third negative terminal portion 43 is in the shape of a column.

[0355] In some embodiments, the third negative terminal portion 43 is riveted to the first negative terminal portion 41 .

[0356] In some embodiments, in the axial direction of the negative lead-out hole 222, the end of the third negative terminal portion 43 away from the second negative terminal portion 42 does not exceed the second through hole 414, so as to reduce the risk of the third negative terminal portion 43 interfering with the connection between the first negative terminal portion 41 and other components (such as the second bus component 7b).

[0357] Optionally, the negative electrode terminal 40 is provided on the first wall portion 20 a , and the axial direction of the negative electrode lead-out hole 222 is parallel to the thickness direction Z of the first wall portion 20 a .

[0358] In some embodiments, the negative terminal 40 includes a third negative terminal portion 43. The first negative terminal portion 41 and the second negative terminal portion 42 may have a relatively small area. Therefore, the third negative terminal portion 43 can stably connect the first negative terminal portion 41 and the second negative terminal portion 42, thereby simplifying the structure of the negative terminal 40 and reducing the volume of the negative terminal 40.

[0359] The first positive terminal portion 31, the second positive terminal portion 32, and the third positive 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 positive terminal portion 31, the second positive terminal portion 32, and the third positive terminal portion 33 is aluminum. For example, the first positive terminal portion 31 is made of aluminum or an aluminum alloy, the second positive terminal portion 32 is made of aluminum or an aluminum alloy, and the third positive terminal portion 33 is made of aluminum or an aluminum alloy.

[0360] The base metal of the second positive electrode terminal 32 is the same as the base metal of the positive electrode tab 12 .

[0361] The second negative terminal portion 42 and the third negative terminal portion 43 include the same base metal. Exemplarily, the base metal of the second negative terminal portion 42 and the third negative terminal portion 43 is copper. For example, the second negative terminal portion 42 is made of copper or a copper alloy, and the third negative terminal portion 43 is made of copper or a copper alloy.

[0362] The base metal of the third negative electrode terminal 43 is the same as the base metal of the negative electrode tab 13 .

[0363] The first negative terminal 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 passes through the second plate 41f and the first plate 41e. As an example, the first plate 41e has a groove, and the second plate 41f is accommodated in the groove.

[0364] The base metal of the first plate 41e is different from the base metal of the second plate 41f. The base metal of the second plate 41f is the same as the base metal of the third negative terminal 43. Optionally, the first negative terminal 41 is a copper-aluminum composite plate.

[0365] The base metal of the first plate 41e is the same as that of the second busbar 7b, facilitating welding. The base metal of the first positive terminal 31 is the same as that of the first busbar 7a, facilitating welding. The first busbar 7a and the second busbar 7b are made of the same material.

[0366] Optionally, in the first direction X, the length of the positive electrode tab 12 is greater than the length of the negative electrode tab 13. By increasing the length of the positive electrode tab 12, the flow area of the positive electrode tab 12 can be increased, the resistance of the positive electrode tab 12 can be reduced, the heat generated by the aluminum positive electrode tab 12 can be reduced, and the temperature difference between the positive electrode tab 12 and the negative electrode tab 13 can be reduced.

[0367] Optionally, in the first direction X, the ratio of the length of the positive electrode tab 12 to the length of the first wall portion 20 a is 0.3-0.5.

[0368] Optionally, the area of the first weld mark 80a is larger than the area of the second weld mark 80b.

[0369] Optionally, the length of the first weld mark 80a is greater than the length of the second weld mark 80b.

[0370] In some embodiments, the projected area of the second positive terminal portion 32 along the thickness direction thereof is larger than the projected area of the second negative terminal portion 42 along the thickness direction thereof.

[0371] Compared with the second negative terminal 42, the second positive terminal 32 can have a larger flow area, thereby reducing the heat generated by the second positive terminal 32 and the heat generated by the positive electrode tab 12, reducing the temperature difference between the positive electrode tab 12 and the negative electrode tab 13, and improving the cycle performance of the battery cell.

[0372] In addition, the first positive terminal portion 31 has a large area to achieve heat exchange with the heat exchange element 9. Setting the second positive terminal portion 32 to have a larger area can reduce the strength difference between the first positive terminal portion 31 and the second positive terminal portion 32, reduce the deformation of the second positive terminal portion 32 when the battery cell 6 is subjected to an external impact, and improve the stability of the fixation of the positive terminal 30 to the first wall portion 20a.

[0373] As an example, the base metal of the second positive terminal 32 is aluminum, and the base metal of the second negative terminal 42 is copper. By increasing the area of the second positive terminal 32, the difference in current capacity between the second positive terminal 32 and the second negative terminal 42 can be reduced.

[0374] In some embodiments, the projected area of the second positive terminal portion 32 along its thickness direction is 1.2-5 times the projected area of the second negative terminal portion 42 along its thickness direction.

[0375] Optionally, the projection area of the second positive terminal portion 32 along 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 projection area of the second negative terminal portion 42 along its own thickness direction.

[0376] Optionally, the projected area of the second positive terminal portion 32 along its thickness direction is 2-3 times the projected area of the second negative terminal portion 42 along its thickness direction.

[0377] The embodiment of the present application can balance the overcurrent capacity of the positive terminal 30 and the overcurrent capacity of the negative terminal 40 to a certain extent, thereby improving the cycle performance of the battery cell 6.

[0378] In some embodiments, the battery cell 6 can be charged at a charge rate of 2C-6C.

[0379] In some embodiments, at room temperature, the charging time for the battery cell 6 to charge from 10% SOC to 80% SOC is less than or equal to 10.5 minutes.

[0380] As an example, the room temperature may be an ambient temperature of 30°C.

[0381] SOC refers to the state of charge of the battery cell 6 .

[0382] For example, 100% SOC and 0% SOC are defined as follows: Charging battery cell 6 at a constant current charge rate of 0.33C to the battery's upper charge voltage limit, followed by constant voltage charging to 0.05C, corresponds to a 100% SOC state for the battery cell; discharging battery cell 6 at a constant current discharge rate of 0.33C to the cutoff voltage corresponds to a 0% SOC state for the battery cell. For example, the battery's upper charge voltage limit and discharge cutoff voltage are marked on the battery cell packaging film.

[0383] Illustratively, 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 consisting of any two of the above values.

[0384] In the embodiment of the present application, the battery cell 6 has a fast charging capability, which can save charging time and improve the user experience. During the fast charging process of the battery cell 6, the first positive terminal can exchange heat with the heat exchange element, thereby reducing the temperature rise of the battery cell 6 and reducing the risk of thermal runaway of the battery cell.

[0385] Figure 12 A schematic structural diagram of an end cap assembly provided in some other embodiments of the present application; Figure 13 for Figure 12 As an example, in Figure 13 , the first region and the second region are shown by oblique lines.

[0386] Reference Figure 12 and Figure 13 In some embodiments, the first region 31a and the second region 31b are flush with each other. This embodiment of the present application can reduce the difficulty of forming the first positive terminal 31 and improve the flatness of the first positive terminal 31.

[0387] In some embodiments, the surface of the first positive terminal 31 away from the first wall 20 a may be a plane.

[0388] In some embodiments, the first positive terminal portion 31 is a rectangular flat plate structure.

[0389] In some embodiments, the area of the second region 31 b is greater than the area of the first region 31 a .

[0390] In some embodiments, the positive terminal 30 includes two third positive terminal portions 33 .

[0391] In some embodiments, the first positive terminal 31 is symmetrical about a plane perpendicular to the first direction X.

[0392] In some embodiments, the first negative terminal portion 41 does not overlap with the heat exchange element in the thickness direction Z.

[0393] In some embodiments, the projected area of the first positive terminal portion 31 along its thickness direction is 2-4 times the projected area of the first negative terminal portion 41 along its thickness direction.

[0394] In some embodiments, W2 is equal to W3.

[0395] In some embodiments, L2 / L3 is 2-5, optionally 3-4.

[0396] Figure 14 Schematic diagram of the structure of the end cover assembly of the battery cell provided in some other embodiments of the present application.

[0397] Reference Figure 14 In some embodiments, the first portion 311 and the second portion 312 are arranged along the first direction X, the dimension W21 of the first portion 311 along the second direction Y is smaller than the dimension W22 of the second 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.

[0398] The thickness of the first portion 311 may be greater than, equal to, or less than the thickness of the second portion 312 .

[0399] In the first direction X, the size of the first portion 311 may be greater than, equal to, or smaller than the size of the second portion 312 .

[0400] The second portion 312 has a larger dimension in the second direction Y. This increases the heat dissipation area of the second portion 312, reduces the temperature rise of the positive terminal 30 and the positive tab 12, and improves the cycle performance of the battery cell 6. The second portion 312 has a smaller thickness. Compared to increasing the dimension of the first portion 311 in the second direction Y, increasing the dimension of the second portion 312 in the second direction Y has a smaller impact on the energy density of the battery cell.

[0401] In addition, the second portion 312 has a larger size in the second direction Y, which can also increase the heat exchange area between the second portion 312 and the heat exchange element, further improving the heat exchange efficiency.

[0402] In some embodiments, the thickness of the second portion 312 is less than that of the first portion 311. Optionally, the first positive terminal 31 is provided with a first recess 313, which is recessed relative to the first portion 311 away from the surface of the first wall portion 20a.

[0403] In some embodiments, a dimension L22 of the second portion 312 along the first direction X may be greater than a dimension L21 of the first portion 311 along the first direction X, so as to further increase the heat exchange area.

[0404] In some embodiments, a dimension W22 of the second portion 312 in the second direction Y is greater than a width W3 of the first negative terminal portion 41 .

[0405] Optionally, a dimension W21 of the first portion 311 in the second direction Y is equal to a width W3 of the first negative terminal portion 41 .

[0406] Figure 15 Schematic diagram of the structure of the end cover assembly of the battery cell provided in some other embodiments of the present application.

[0407] Reference Figure 15 In some embodiments, the first portion 311 and the second portion 312 are spaced apart along a first direction X, and the first direction X is perpendicular to a thickness direction Z of the first wall portion 20 a.

[0408] The first portion 311 and the second portion 312 can be formed independently, which is beneficial to the processing and forming of the parts, and can also get rid of the size limitation caused by the limitation of manufacturing capacity, and provide a larger area of the second portion 312, thereby improving the heat dissipation effect.

[0409] In some embodiments, the first portion 311 is connected to the second positive terminal portion through at least one third positive terminal portion 33 , and the second portion 312 is connected to the second positive terminal portion through at least one third positive terminal portion 33 .

[0410] The two third positive terminal portions 33 may respectively fix the first portion 311 and the second portion 312 to the first wall portion 20 a to keep the relative positions of the first portion 311 and the second portion 312 fixed.

[0411] In some embodiments, the thickness of the second portion 312 may be less than the thickness of the first portion 311 .

[0412] Optionally, a surface of the first portion 311 facing the first wall portion 20 a is flush with a surface of the second portion 312 facing the first wall portion 20 a .

[0413] In some embodiments, the first portion 311 and the second portion 312 have the same shape and size. The first portion 311 and the second portion 312 are identical components, which can save costs and reduce assembly difficulty.

[0414] In some embodiments, the area of the second portion 312 is greater than the area of the first negative terminal portion 41 .

[0415] Figure 16 A schematic structural diagram of an end cap assembly of a battery cell provided in some other embodiments of the present application; Figure 17 for Figure 16 A schematic cross-sectional view of the end cap assembly is shown.

[0416] Reference Figure 16 In some embodiments, the first positive terminal 31 is configured such that it at least partially overlaps with the heat exchange element of the battery in the thickness direction Z of the first wall. The third positive terminal 33 is configured such that it does not overlap with the heat exchange element 9 in the thickness direction Z.

[0417] By avoiding the third positive terminal 33 from the heat exchange element, the risk of interference between the third positive terminal 33 and the heat exchange element can be reduced, and the flatness of the heat exchange interface between the first positive terminal 31 and the heat exchange element can be improved.

[0418] In some embodiments, there is one first through hole 314 .

[0419] In some embodiments, the first region 31 a and the second region 31 b are respectively located on two sides of the first through hole 314 along the first direction X.

[0420] In some embodiments, the first positive terminal 31 includes a first edge 31 c and a second edge 31 d that are oppositely disposed along a first direction X, where the first direction X is parallel to the length of the first wall portion 20 a. In the first direction X, a minimum distance D4 between the axis of the first through hole 314 and the first edge 31 c is equal to a minimum distance D5 between the axis of the first through hole 314 and the second edge 31 d.

[0421] In the embodiment of the present application, the first through hole 314 and the third positive terminal portion 33 are centrally arranged, which can improve the structural strength of the positive terminal 30 and reduce the risk of deformation of the first positive terminal portion 31 .

[0422] In some embodiments, the first negative terminal portion 41 is used to connect to the second busbar 7 b of the battery and exchange heat with the heat exchange element 9 of the battery.

[0423] During the cycle of battery 2, both the first positive terminal 31 and the first negative terminal 41 can exchange heat with the heat exchange element, thereby further improving the heat dissipation capacity of the battery cell 6, reducing the temperature rise of the battery cell 6, improving the cycle performance and cycle life of the battery cell 6, and reducing the risk of thermal runaway of the battery cell 6 during rapid charging. The negative terminal 40 is connected to the negative electrode tab, and the heat of the negative electrode tab can also be transferred to the heat exchange element through the first negative terminal 41, thereby reducing the temperature rise of the electrode assembly and improving the cycle performance and cycle life of the battery cell 6. The first negative terminal 41 can simultaneously dissipate heat and transmit current, which helps to shorten the heat transfer path between the heat source and the heat exchange element and improve heat dissipation efficiency.

[0424] In some embodiments, the surface of the first negative terminal 41 away from the housing 20 is configured to be connected to a heat exchange member. As an example, the surface of the first negative terminal 41 away from the housing 20 can be a flat surface or a stepped surface.

[0425] In some embodiments, the negative electrode terminal 40 is disposed on the first wall portion 20a. The second weld mark 80b is configured to at least partially overlap the heat exchange element in the thickness direction Z of the first wall portion 20a.

[0426] In some embodiments, the negative terminal 40 is disposed on the first wall portion 20a. The surface of the first negative terminal portion 41 away from the first wall portion 20a includes a third region 41a and a fourth region 41b. The third region 41a is configured to overlap and connect with the second flow conduit member 7b in the thickness direction Z. The fourth region 41b is configured to overlap with the heat exchange element 9 in the thickness direction Z.

[0427] As an example, the third region 41 a is disposed in contact with the second current collecting member.

[0428] As an example, in the thickness direction Z, the projection of the fourth region 41 b is located within the projection of the heat exchange element.

[0429] The third region 41 a and the fourth region 41 b may be flush with each other or may be offset in the thickness direction Z of the first wall portion 20 a .

[0430] The third area 41a and the fourth area 41b may be directly connected or spaced apart.

[0431] In some embodiments, the area of the fourth region 41b is larger than the area of the third region 41a. The larger area of the fourth region 41b can improve the heat exchange efficiency between the heat exchange element and the first negative terminal 41, reduce the temperature rise of the first negative terminal 41, and improve the cycle performance and reliability of the battery cell 6.

[0432] In some embodiments, the third region 41 a and the fourth region 41 b are respectively located on two sides of the second through hole 414 along the first direction X.

[0433] In some embodiments, the first negative terminal portion 41 has a third edge 41c and a fourth edge 41d at both ends along the first direction X, and in the second direction Y, the minimum distance between the axis of the second through hole 414 and the third edge 41c is equal to the minimum distance between the axis of the second through hole 414 and the fourth edge 41d.

[0434] In some embodiments, the area of the second region 31b is larger than the area of the fourth region 41b. The positive electrode tab and positive terminal 30 are both made of copper, while the negative electrode tab and a portion of the negative terminal 40 are also made of copper. The positive electrode tab and positive terminal 30 generate more heat. Providing a larger area of the second region 31b than the fourth region 41b can improve the heat exchange efficiency between the positive terminal 30 and the heat exchange element and reduce the temperature difference between the positive and negative electrode tabs.

[0435] In some embodiments, (L2×W2) / (L3×W3) is 1.2-5, and can be optionally 2-3.

[0436] In some embodiments, the first region 31 a , the second region 31 b , the fourth region 41 b , and the third region 41 a are sequentially spaced apart along a first direction X, and the first direction X is perpendicular to the thickness direction Z.

[0437] The second region 31b and the fourth region 41b are adjacently arranged along the first direction X. The same heat exchange element can exchange heat with the second region 31b and the fourth region 41b at the same time, thereby simplifying the structure of the battery.

[0438] In some embodiments, in the thickness direction Z of the first wall portion 20 a , a projected area of the first negative terminal portion 41 is 0.2-0.5 times the projected area of the first wall portion 20 a .

[0439] Figure 18 Schematic top view of the end cover assembly of the battery cell provided in some other embodiments of the present application.

[0440] Reference Figure 18 In some embodiments, the second region 31b, the first region 31a, the third region 41a, and the fourth region 41b are sequentially spaced apart along the first direction X, and the first direction X is perpendicular to the thickness direction Z.

[0441] When multiple battery cells 6 are arranged along the first direction X, the second area 31b of one battery cell 6 is adjacent to the fourth area 41b (or second area 31b) of another battery cell 6, and the same heat exchange element can exchange heat with two battery cells 6 at the same time, thereby simplifying the structure of the battery 2.

[0442] In some embodiments, in the first direction X, the minimum distance D5 between the axis of the first through hole 314 and the first edge 31c is smaller than the minimum distance D4 between the axis of the first through hole 314 and the second edge 31d, and the portion of the first positive terminal portion 31 between the first edge 31c and the first through hole 314 is used to connect with the first busbar component 7a of the battery, and the portion of the first positive terminal portion 31 between the second edge 31d and the first through hole 314 is used to exchange heat with the heat exchange element 9 of the battery.

[0443] Exemplarily, at least a portion of the first region 31 a is located between the first edge 31 c and the first through hole 314 , and at least a portion of the second region 31 b is located between the second edge 31 d and the first through hole 314 .

[0444] In this embodiment, the eccentric design of the first through hole 314 allows for a larger area to exchange heat with the heat exchange component, thereby improving heat exchange efficiency. This embodiment also reduces the distance between the third positive terminal 33 and the first current collector, shortening the conductive path, reducing resistance, and reducing heat generation.

[0445] In some embodiments, in the first direction X, the minimum distance between the axis of the second through hole 414 and the third edge 41c is smaller than the minimum distance between the axis of the second through hole 414 and the fourth edge 41d, and the portion of the first negative terminal portion 41 between the third edge 41c and the second through hole 414 is used to connect with the second busbar component 7b of the battery, and the portion of the first negative terminal portion 41 between the fourth edge 41d and the second through hole 414 is used to exchange heat with the heat exchange element 9 of the battery.

[0446] Figure 19 Schematic diagram of the structure of the end cover assembly of the battery cell provided in some other embodiments of the present application.

[0447] Reference Figure 19 In some embodiments, the negative terminal 40 includes a plurality of third negative terminal portions 43 disposed at intervals. The provision of multiple third negative terminal portions 43 can improve current flow capacity, reduce heat generation, increase the structural strength of the negative terminal 40, and enhance the stability of the connection between the negative terminal 40 and the housing 20.

[0448] In some embodiments, there are multiple negative electrode lead-out holes, and the multiple negative electrode lead-out holes are arranged in a one-to-one correspondence with the multiple third negative electrode terminals 43 .

[0449] In some embodiments, the first negative terminal 41 includes a third portion 411 and a fourth portion 412 . The third portion 411 is used to connect to the second busbar component, and the fourth portion 412 is used to exchange heat with the heat exchange element.

[0450] The thickness of the third portion 411 and the thickness of the fourth portion 412 may be the same or different.

[0451] In the first direction X, the size of the third portion 411 may be the same as or different from the size of the fourth portion 412 ; in the second direction Y, the size of the third portion 411 may be the same as or different from the size of the fourth portion 412 .

[0452] The third portion 411 and the fourth portion 412 may be connected or separated.

[0453] In some embodiments, the third portion 411 is connected to the second negative terminal portion 42 through at least one third negative terminal portion 43 , and the fourth portion 412 is connected to the second negative terminal portion 42 through at least one third negative terminal portion 43 .

[0454] In some embodiments, the third portion 411 is configured to at least partially overlap and connect with the second confluence member in the thickness direction Z of the first wall portion 20 a , and the fourth portion 412 is configured to at least partially overlap with the heat exchange element in the thickness direction Z.

[0455] In some embodiments, the second conduit component is disposed on a side of the third portion 411 away from the first wall portion 20 a and connected to the third portion 411 .

[0456] In some embodiments, the heat exchange element is disposed on a side of the fourth portion 412 away from the first wall portion 20 a .

[0457] In some embodiments, the third portion 411 includes a third region 41 a and the fourth portion 412 includes a fourth region 41 b.

[0458] In some embodiments, the thickness of the third portion 411 is greater than or equal to the thickness of the fourth portion 412. Alternatively, the thickness of the third portion 411 is greater than the thickness of the fourth portion 412.

[0459] In some embodiments, the thickness of the third portion 411 is greater than or equal to 3 mm.

[0460] In some embodiments, the thickness of the third portion 411 is equal to the thickness of the first portion 311 , and the thickness of the fourth portion 412 is equal to the thickness of the second portion 312 .

[0461] In some embodiments, the ratio of the thickness of the third portion 411 to the fourth portion 412 is 1.2-3, and can be 1.2, 1.5, 2, 2.5 or 3.

[0462] In some embodiments, the third portion 411 extends beyond the fourth portion 412 in a direction away from the first wall portion 20 a .

[0463] In some embodiments, a side of the first negative terminal 41 away from the first wall 20 a has a second recess 413 , and the fourth portion 412 is a bottom wall of the second recess 413 .

[0464] In some embodiments, the second busbar is laser welded to the third portion 411 .

[0465] In some embodiments, the second recess 413 is located on one side of the third portion 411 along the first direction X. An end of the second recess 413 away from the third portion 411 along the first direction X may extend to an edge of the first negative terminal 41 .

[0466] In some embodiments, along the second direction Y, the second recess 413 passes through the first negative terminal 41 .

[0467] In some embodiments, in the thickness direction Z of the first wall portion 20 a , the depth of the second recess 413 is 0.1 mm-2 mm.

[0468] In some embodiments, the depth of the second recess 413 is equal to the depth of the first recess 313 .

[0469] In some embodiments, when viewed in the thickness direction Z, the area of the fourth portion 412 is larger than the area of the third portion 411 , so that the heat exchange area between the first negative terminal 41 and the heat exchange element can be larger.

[0470] In some embodiments, the third portion 411 and the fourth portion 412 are arranged along the first direction X, and the size of the third portion 411 along the second direction Y is less than or equal to the size of the fourth portion 412 along the second direction Y. Optionally, the size of the third portion 411 along the second direction Y is less than the size of the fourth portion 412 along the second direction Y.

[0471] In some embodiments, the size of the third portion 411 along the second direction Y is equal to the size of the first portion 311 along the second direction Y. The size of the fourth portion 412 along the second direction Y is equal to the size of the second portion 312 along the second direction Y.

[0472] In some embodiments, the third portion 411 and the fourth portion 412 may be disposed continuously along the first direction X, or may be disposed at intervals along the first direction X.

[0473] In some embodiments, the size of the third portion 411 along the first direction X is smaller than or equal to the size of the fourth portion 412 along the second direction Y. Alternatively, the size of the third portion 411 along the first direction X is smaller than the size of the fourth portion 412 along the first direction X.

[0474] In some embodiments, in the thickness direction Z of the first wall portion 20 a , the projected area of the second portion 312 is greater than or equal to the projected area of the fourth portion 412 , and the projected area of the first portion 311 is greater than or equal to the projected area of the third portion 411 .

[0475] Optionally, in the thickness direction Z of the first wall portion 20 a , the projection area of the second portion 312 is larger than the projection area of the fourth portion 412 , and the projection area of the first portion 311 is larger than the projection area of the third portion 411 .

[0476] In some embodiments, in the first direction X, a size of the second portion 312 is greater than a size of the fourth portion 412 .

[0477] In some embodiments, the first portion 311 , the second portion 312 , the fourth portion 412 , and the third portion 411 are sequentially arranged in the first direction X. The second portion 312 and the fourth portion 412 are adjacently arranged along the first direction X.

[0478] The first portion 311 and the third portion 411 are respectively disposed at two ends of the first wall portion 20 along the first direction X, so as to facilitate the arrangement of multiple battery cells into groups.

[0479] The same heat exchange element can exchange heat with the second portion 312 and the fourth portion 412 at the same time, thereby simplifying the structure of the battery.

[0480] Figure 20 Schematic diagram of the structure of the end cover assembly of the battery cell provided in some other embodiments of the present application.

[0481] Reference Figure 20 In some embodiments, the third portion 411 and the fourth portion 412 may be spaced apart along the first direction X.

[0482] Optionally, the third portion 411 is connected to the second negative terminal portion 42 via a third negative terminal portion 43 , and the fourth portion 412 is connected to the second negative terminal portion 42 via a third negative terminal portion 43 .

[0483] Optionally, the third portion 411 and the fourth portion 412 are both copper-aluminum composite plates.

[0484] In some embodiments, the second portion 312 , the first portion 311 , the third portion 411 , and the fourth portion 412 are sequentially arranged in the first direction X. The first portion 311 and the third portion 411 are oppositely arranged along the first direction X to facilitate the arrangement of multiple battery cells into groups.

[0485] When multiple battery cells 6 are arranged along the first direction X, the second portion 312 of one battery cell 6 is adjacent to the fourth portion 412 (or second portion 312) of another battery cell 6, and the same heat exchange element can exchange heat with two battery cells 6 at the same time, thereby simplifying the battery structure.

[0486] In some embodiments, the thickness of the fourth portion 412 is less than the thickness of the third portion 411 .

[0487] Figure 21 A simplified schematic diagram of a battery cell provided for some other embodiments of the present application.

[0488] Reference Figure 21 In some embodiments, the housing 20 includes a second wall portion 20 b , and the negative terminal 40 is disposed on the second wall portion 20 b .

[0489] By arranging the positive terminal 30 and the negative terminal 40 on the first wall portion 20a and the second wall portion 20b respectively, the first positive terminal portion 31 and the first negative terminal portion 41 can have a larger area, thereby improving the heat dissipation efficiency and the current flow capacity, and improving the cycle performance of the battery cell 6.

[0490] Disposing the positive terminal 30 and the negative terminal 40 at opposite ends of the housing 20 can also reduce the risk of short circuit.

[0491] In some embodiments, the positive terminal 30 includes a first portion 311 and a second portion 312 , and the first portion 311 and the second portion 312 are spaced apart along the first direction X.

[0492] In some embodiments, the negative terminal 40 includes a third portion 411 and a fourth portion 412 , and the third portion 411 and the fourth portion 412 are spaced apart along the first direction X.

[0493] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the first positive 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.

[0494] Setting S1 / S3 to be greater than or equal to 0.3 allows the first positive terminal 31 to have a larger area, thereby increasing the heat dissipation and current carrying capacity of the positive terminal 30 and improving the cycle performance of the battery cell 6. Setting S1 / S3 to be less than or equal to 0.8 allows for installation space to be reserved for other components, reducing the impact of increasing the first positive terminal 31 on the energy density of the battery cell 6.

[0495] In some embodiments, in the thickness direction Z of the first wall portion 20a, the projected area of the first negative 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; alternatively, 0.3 ≤ S2 / S3 ≤ 0.5. S2 is smaller than S1.

[0496] Setting S2 / S3 to be greater than or equal to 0.3 allows the first negative terminal portion 41 to have a larger area, thereby increasing the heat dissipation and current carrying capacity of the negative terminal 40 and improving the cycle performance of the battery cell 6. Setting S2 / S3 to be less than or equal to 0.8 allows for the installation of other components and reduces the impact of increasing the first negative terminal portion 41 on the energy density of the battery cell 6.

[0497] In some embodiments, heat exchangers may be provided on both sides of the battery cell 6 . The heat exchanger on one side of the battery cell 6 exchanges heat with the positive terminal 30 , and the heat exchanger on the other side of the battery cell 6 exchanges heat with the negative terminal 40 .

[0498] Figure 22 A schematic cross-sectional view of a battery provided in some embodiments of the present application.

[0499] Reference Figure 22 In some embodiments, the battery 2 includes a battery cell 6, a first current collector 7a, and a heat exchanger 9. The first current collector 7a is connected to the first positive terminal 31. At least a portion of the heat exchanger 9 is located on a side of the first wall 20a facing away from the electrode assembly 10 and exchanges heat with the first positive terminal 31.

[0500] In some embodiments, the battery 2 further includes a second current collecting member 7 b connected to the first negative terminal 41 .

[0501] In some embodiments, in the thickness direction Z of the first wall portion 20 a , a portion of the first positive terminal portion 31 is located between the heat exchange element 9 and the first wall portion 20 a .

[0502] The heat exchange element 9 can exchange heat with the first positive terminal portion 31 , thereby increasing the heat dissipation efficiency of the battery cell 6 and improving the cycle performance of the battery cell 6 .

[0503] In some embodiments, in the thickness direction Z of the first wall portion 20 a , a portion of the first negative terminal portion 41 is located between the heat exchange element 9 and the first wall portion 20 a .

[0504] The heat exchange element 9 can exchange heat with the first negative terminal portion 41 , thereby increasing the heat dissipation efficiency of the battery cell 6 and improving the cycle performance of the battery cell 6 .

[0505] In some embodiments, the battery 2 includes a housing 5 , in which the battery cells 6 and the first busbar 7 a are housed.

[0506] In some embodiments, a plurality of battery cells 6 are housed in the box 5 .

[0507] In some embodiments, the heat exchange element 9 is disposed outside the box body 5 , which can save the internal space of the box body 5 and improve space utilization.

[0508] In some embodiments, the heat exchange element 9 exchanges heat with the positive terminal 30 and the negative terminal 40 through the wall of the box body 5 .

[0509] In some embodiments, the box wall and the first positive terminal portion 31 of the positive terminal 30 are bonded together by insulating thermally conductive adhesive 9a.

[0510] In some embodiments, the box wall and the first negative terminal portion 41 of the negative terminal 40 are bonded together by insulating thermally conductive adhesive 9 a.

[0511] In some embodiments, the plurality of battery cells 6 are arranged along the first direction X.

[0512] In some embodiments, the heat exchange element 9 is a heat exchange tube extending along the second direction Y.

[0513] Illustratively, in the thickness direction Z of the first wall portion 20 a , one heat exchange tube at least partially overlaps the second portion 312 of one battery cell 6 , and at least partially overlaps the fourth portion 412 of another battery cell 6 .

[0514] According to some embodiments of the present application, the present application further provides an electrical device comprising a battery according to any of the above embodiments, the battery being used to provide electrical energy to the electrical device. The electrical device may be any of the aforementioned devices or systems using the battery.

[0515] Reference Figure 3-8 and Figure 19 , an embodiment of the present application provides a battery cell 6 , which includes a housing 20 , an electrode assembly 10 , a positive terminal 30 and a negative terminal 40 .

[0516] The electrode assembly 10 is housed in a housing 20 and includes a positive electrode tab 12 and a negative electrode tab 13 .

[0517] The housing 20 includes a first wall portion 20 a , and the first wall portion 20 a is provided with a positive electrode lead-out hole 221 and a negative electrode lead-out hole 222 .

[0518] The positive terminal 30 includes a first positive terminal portion 31, a second positive terminal portion 32, and a third positive terminal portion 33. The first positive terminal portion 31 is located outside the first wall portion 20a, the second positive terminal portion 32 is located inside the first wall portion 20a and connected to the positive electrode tab 12, and at least a portion of the third positive terminal portion 33 is accommodated in the positive electrode lead-out hole 221, and the third positive terminal portion 33 connects the second positive terminal portion 32 and the first positive terminal portion 31. In the thickness direction Z of the first wall portion 20a, a portion of the first wall portion 20a is located between the first positive terminal portion 31 and the second positive terminal portion 32.

[0519] The negative terminal 40 includes a first negative terminal portion 41, a second negative terminal portion 42, and a third negative terminal portion 43. The first negative terminal portion 41 is located outside the first wall portion 20a, the second negative terminal portion 42 is located inside the first wall portion 20a and is connected to the negative electrode tab 13, and at least a portion of the third negative terminal portion 43 is accommodated in the negative electrode lead-out hole 222. The third negative terminal portion 43 connects the second negative terminal portion 42 and the first negative terminal portion 41. In the thickness direction Z of the first wall portion 20a, a portion of the first wall portion 20a is located between the first negative terminal portion 41 and the second negative terminal portion 42.

[0520] The first positive terminal 31 includes a first portion 311 and a second portion 312 arranged along the first direction X. The first portion 311 is thicker than the second portion 312. A first recess 313 is defined on the side of the first positive terminal 31 away from the first wall 20a. The second portion 312 forms the bottom wall of the first recess 313. Two third positive terminals 33 are provided, each connected to the first portion 311 and the second portion 312.

[0521] The first negative terminal 41 includes a third portion 411 and a fourth portion 412 arranged along the first direction X. The third portion 411 is thicker than the fourth portion 412. A second recess 413 is defined on the side of the first negative terminal 41 away from the first wall 20a. The fourth portion 412 serves as the bottom wall of the second recess 413. Two third negative terminal portions 43 are provided, each connected to the third portion 411 and the fourth portion 412.

[0522] The first portion 311 , the second portion 312 , the fourth portion 412 , and the third portion 411 are disposed along the first direction X.

[0523] The first portion 311 is used to connect to the first conduit member 7a of the battery 2, and the third portion 411 is used to connect to the second conduit member 7b of the battery 2. The second portion 312 and the fourth portion 412 are used to exchange heat with the heat exchange member 9.

[0524] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0525] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions 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 comprising a first wall portion; an electrode assembly housed in the housing, the electrode assembly comprising a positive electrode tab and a negative electrode tab; as well as a positive terminal, disposed on the first wall portion and electrically connected to the positive electrode tab, the positive terminal comprising a first positive terminal portion located outside the first wall portion; and A negative terminal is provided in the shell and electrically connected to the negative electrode tab, the negative terminal including a first negative terminal portion located outside the shell, and a projected area of the first positive terminal portion along its own thickness direction is larger than a projected area of the first negative terminal portion along its own thickness direction.

2. The battery cell according to claim 1, wherein: The first positive terminal is used to connect to a first busbar of a battery and exchange heat with a heat exchange element of the battery.

3. The battery cell according to claim 2, characterized in that: The first positive terminal portion includes a first portion and a second portion, the first portion is used to connect with the first confluence component, and the second portion is used to exchange heat with the heat exchange element.

4. The battery cell according to claim 3, characterized in that The first portion is configured to at least partially overlap and connect with the first confluence member in the thickness direction of the first wall portion, and the second portion is configured to at least partially overlap with the heat exchange element in the thickness direction of the first wall portion.

5. The battery cell according to claim 3, characterized in that: The thickness of the first portion is greater than the thickness of the second portion.

6. The battery cell according to claim 3, characterized in that The first portion extends beyond the second portion in a direction away from the first wall portion.

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

8. The battery cell according to claim 7, characterized in that In the thickness direction of the first wall portion, the depth of the first recess is 0.1 mm to 2 mm.

9. The battery cell according to claim 3, characterized in that: The first part and the second part are arranged along the first direction, the size of the first part along the second direction is smaller than the size of the second part 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.

10. The battery cell according to claim 3, characterized in that The first portion and the second portion are spaced apart along a first direction, and the first direction is perpendicular to a thickness direction of the first wall portion.

11. The battery cell according to claim 3, characterized in that The first portion and the second portion are arranged along a first direction, the first direction being perpendicular to a thickness direction of the first wall portion; In the first direction, a size of the second portion is larger than a size of the first portion.

12. The battery cell according to claim 2, characterized in that: A surface of the first positive terminal away from the first wall is configured to be connected to the heat exchange element.

13. The battery cell according to claim 2, characterized in that The surface of the first positive terminal away from the first wall portion includes a first area and a second area, the first area is configured to overlap and connect with the first conduit component in the thickness direction of the first wall portion, and the second area is configured to overlap with the heat exchange element in the thickness direction of the first wall portion.

14. The battery cell according to claim 13, characterized in that The first area and the second area are spaced apart.

15. The battery cell according to claim 13, characterized in that The area of the second region is larger than that of the first region.

16. The battery cell according to claim 13, characterized in that A ratio of an area of the first region to a projected area of the first positive terminal portion along a thickness direction of the first wall portion is greater than or equal to 1.5%.

17. The battery cell according to claim 13, characterized in that A ratio of an area of the second region to a projected area of the first positive terminal portion along a thickness direction of the first wall portion is greater than or equal to 10%.

18. The battery cell according to any one of claims 1 to 17, characterized in that: The first wall portion is provided with a positive electrode lead-out hole; The positive terminal further includes a second positive terminal portion and a third positive terminal portion, the second positive terminal portion is located inside the first wall portion and is electrically connected to the positive electrode tab, and at least a portion of the third positive terminal portion is accommodated in the positive electrode lead-out hole, and the third positive terminal portion is connected to the second positive terminal portion and the first positive terminal portion; A portion of the first wall portion is located between the first positive pole terminal portion and the second positive pole terminal portion in a thickness direction of the first wall portion.

19. The battery cell according to claim 18, characterized in that The second positive terminal portion and the third positive terminal portion are integrally formed.

20. The battery cell according to claim 18, characterized in that The first positive terminal portion is provided with a first through hole, and the first through hole penetrates the first positive terminal portion along the thickness direction of the first wall portion; A portion of the third positive terminal is received in the first through hole and connected to the first positive terminal.

21. The battery cell according to claim 20, characterized in that In the thickness direction of the first wall portion, an end of the third positive terminal portion away from the second positive terminal portion does not extend beyond the first through hole.

22. The battery cell according to claim 20, characterized in that The first positive terminal portion is configured such that: the first positive terminal portion at least partially overlaps with the heat exchange element of the battery in the thickness direction of the first wall portion; The third positive terminal is arranged so as not to overlap with the heat exchange element in a thickness direction of the first wall.

23. The battery cell according to claim 20, characterized in that The first positive terminal portion includes a first edge and a second edge disposed opposite to each other along a first direction, wherein the first direction is parallel to a length direction of the first wall portion; In the first direction, the minimum distance between the axis of the first through hole and the first edge is equal to the minimum distance between the axis of the first through hole and the second edge; or, in the first direction, the minimum distance between the axis of the first through hole and the first edge is smaller than the minimum distance between the axis of the first through hole and the second edge, the portion of the first positive terminal portion located between the first edge and the first through hole is used to connect with the first busbar component of the battery, and the portion of the first positive terminal portion located between the second edge and the first through hole is used to exchange heat with the heat exchange component of the battery.

24. The battery cell according to claim 18, characterized in that The positive terminal includes a plurality of third positive terminal portions that are spaced apart from each other.

25. The battery cell according to claim 24, characterized in that The first positive terminal portion includes a first portion and a second portion spaced apart along a first direction, wherein the first direction is perpendicular to a thickness direction of the first wall portion; The first portion is connected to the second positive terminal portion through at least one third positive terminal portion, and the second portion is connected to the second positive terminal portion through at least one third positive terminal portion.

26. The battery cell according to claim 24, characterized in that The first positive terminal portion includes a first edge and a second edge disposed opposite to each other along a first direction, wherein the first direction is parallel to a length direction of the first wall portion; The first positive terminal portion is provided with two first through holes spaced apart along the first direction, and the two third positive terminals are respectively passed through the two first through holes and connected to the first positive terminal 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.

27. The battery cell according to claim 18, characterized in that A cross section of the third positive terminal portion perpendicular to the thickness direction of the first wall portion is circular, elliptical, or racetrack-shaped.

28. The battery cell according to claim 18, characterized in that The positive electrode tab is welded to the second positive terminal portion to form a first weld mark.

29. The battery cell according to claim 28, characterized in that The first weld mark is configured to at least partially overlap with the heat exchange element of the battery in a thickness direction of the first wall portion.

30. The battery cell according to claim 18, wherein In the thickness direction of the first wall portion, a projected area of the first positive terminal portion is larger than a projected area of the second positive terminal portion.

31. The battery cell according to claim 18, characterized in that In the thickness direction of the first wall portion, a projected area of the second positive terminal portion is 0.2-0.5 times a projected area of the first wall portion.

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

33. The battery cell according to claim 1, characterized in that The first negative terminal is used to connect to a second busbar of the battery and exchange heat with a heat exchange element of the battery.

34. The battery cell according to claim 33, characterized in that The negative terminal is provided on the first wall portion; The surface of the first positive terminal away from the first wall portion includes a first area and a second area, the first area being configured to overlap and connect with the first current collecting member of the battery in the thickness direction of the first wall portion; The surface of the first negative terminal away from the first wall portion includes a third region and a fourth region, the third region being configured to overlap and connect with the second current collecting member in the thickness direction of the first wall portion; The second region and the fourth region are configured to overlap with the heat exchange element in a thickness direction of the first wall portion; The second area, the first area, the third area, and the fourth area are sequentially spaced apart along the first direction, or the first area, the second area, the fourth area, and the third area are sequentially spaced apart along the first direction; The first direction is perpendicular to a thickness direction of the first wall portion.

35. The battery cell according to claim 1, characterized in that The shell is provided with a positive electrode lead-out hole and a negative electrode lead-out hole; The positive terminal further includes a second positive terminal portion and a third positive terminal portion, the second positive terminal portion is located inside the first wall portion and is electrically connected to the positive electrode tab, and at least a portion of the third positive terminal portion is accommodated in the positive electrode lead-out hole, and the third positive terminal portion is connected to the second positive terminal portion and the first positive terminal portion; The negative terminal further includes a second negative terminal portion and a third negative terminal portion, wherein the second negative terminal portion is located inside the housing and electrically connected to the negative electrode tab, and at least a portion of the third negative terminal portion is accommodated in the negative electrode lead-out hole, and the third negative terminal portion is connected to the second negative terminal portion and the first negative terminal portion; A projected area of the second positive terminal portion along its thickness direction is larger than a projected area of the second negative terminal portion along its thickness direction.

36. The battery cell according to claim 1, characterized in that The projected area of the first positive terminal portion along its thickness direction is 1.2-5 times the projected area of the first negative terminal portion along its thickness direction.

37. The battery cell according to claim 1, characterized in that The positive terminal and the negative terminal are both provided on the first wall portion; In the thickness direction of the first wall portion, the projected area of the first positive terminal portion is S1, the projected area of the first negative 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.

38. The battery cell according to claim 1, characterized in that The housing includes a second wall portion, and the negative terminal is provided on the second wall portion; In the thickness direction of the first wall portion, the projected area of the first positive 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.

39. The battery cell according to claim 1, wherein: The material of the positive electrode tab is aluminum, and the material of the negative electrode tab is copper; The positive terminal is made of aluminum or an aluminum alloy, and at least a portion of the negative terminal is made of copper or a copper alloy.

40. The battery cell according to claim 1, wherein The negative terminal is provided on the first wall portion; In the thickness direction of the first wall portion, the first positive terminal portion overlaps with the heat exchange element of the battery, and the first negative terminal portion does not overlap with the heat exchange element.

41. 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.

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 having an opening, the end cover being connected to the shell and covering the opening; The end cover is the first wall portion.

44. A battery, characterized in that include: The battery cell according to any one of claims 1 to 43; a first busbar connected to the first positive terminal; as well as A heat exchange component, 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 positive terminal portion.

45. The battery according to claim 44, characterized in that In the thickness direction of the first wall portion, a portion of the first positive terminal portion is located between the heat exchange member 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 confluence member are accommodated in the box body, and the heat exchange member 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.

Images