Battery cells, battery packs, electrical devices and energy storage devices

Abstract

This application provides a battery cell, a battery device, an electrical device, and an energy storage device, belonging to the field of battery technology. The battery cell includes a casing, an electrode assembly housed within the casing, and electrode terminals disposed on the casing. The electrode assembly includes an electrode body and a tab. The electrode terminal includes a main body portion. A first end of the main body portion along its axial direction is electrically connected to a current-collecting component, and a second end of the main body portion along its axial direction is electrically connected to the tab. The first end of the main body portion has a first weld pool electrically connected to the current-collecting component, and the second end of the main body portion has a second weld pool electrically connected to the tab. Using a plane perpendicular to the axial direction as a reference plane, the first orthographic projection of the first weld pool on the reference plane and the second orthographic projection of the second weld pool on the reference plane are offset from each other, and the third orthographic projection of the first weld pool in the axial direction and the fourth orthographic projection of the second weld pool in the axial direction at least partially overlap, which can improve the energy density of the battery cell.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, battery device, power supply device, and energy storage device. Background Technology

[0002] Energy conservation and emission reduction are key to sustainable social development, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of the automotive industry's sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0003] The energy density of a battery cell refers to the energy stored per unit volume of a battery. It is a key indicator for measuring the performance of a battery cell and directly affects the performance of devices using it, such as battery life. Therefore, how to improve the energy density of a battery cell has become a problem worthy of attention. Utility Model Content

[0004] This application aims to at least address one of the technical problems existing in the background art. Therefore, one object of this application is to provide a battery cell, battery device, power consumption device, and energy storage device to improve the energy density of the battery cell.

[0005] An embodiment of the first aspect of this application provides a battery cell, including: a housing, an electrode assembly, and an electrode terminal. The housing has a receiving cavity; the electrode assembly is received in the receiving cavity, and the electrode assembly includes an electrode body and a tab disposed at one end of the electrode body; the electrode terminal is disposed on the housing, and the electrode terminal includes a main body portion, a first end of the main body portion along the axial direction for electrical connection with a current-connecting component, a second end of the main body portion along the axial direction for electrical connection with the tab, and the first end of the main body portion has a first weld pool for electrical connection with the current-connecting component, and the second end of the main body portion has a second weld pool for electrical connection with the tab; taking a plane perpendicular to the axial direction as a reference plane, the first orthographic projection of the first weld pool on the reference plane and the second orthographic projection of the second weld pool on the reference plane are offset from each other, and the third orthographic projection of the first weld pool in the axial direction and the fourth orthographic projection of the second weld pool in the axial direction at least partially coincide.

[0006] In the technical solution of this application embodiment, by having the third and fourth orthographic projections partially overlap, the first and second welding pools can share a common space in the axial direction. This reduces the height of the main body in the axial direction, allowing the battery cell to store more energy in the same volume, thereby increasing the energy density of the battery cell and battery device. Simultaneously, by staggering the first and second orthographic projections, the first and second welding pools will not connect (interfere), thus improving the phenomenon of weld penetration in the main body. This mitigates the airtightness failure of the main body caused by weld penetration, preventing leakage of the battery cell.

[0007] In some embodiments, the electrode terminal includes a first electrode terminal, the main body of the first electrode terminal includes a first segment and a second segment, the second segment is connected to one end of the first segment along the axial direction, the first segment is provided with a first weld pool, the second segment is provided with a second weld pool, and the constituent material of the first segment is different from the constituent material of the second segment.

[0008] In this embodiment, by using a main body made of composite material, the connection strength between the main body and the busbar and adapter can be improved.

[0009] In some embodiments, the first weld pool also extends along the axial direction to a portion located in the second segment.

[0010] By placing a portion of the first welding pool in the second section, the first welding pool and the second welding pool can share more height space along the axial direction, allowing the height of the shared portion to approach the height of the second section. This further reduces the height of the main body in the axial direction, thereby increasing the energy density of the battery cell and battery device.

[0011] In some embodiments, the second weld pool also extends along the axial direction to a portion located within the first segment.

[0012] In this embodiment, the first welding pool and the second welding pool share more height space along the axial direction, so that the height of the shared part can be close to the height of the first segment, which can further reduce the height of the main body in the axial direction and improve the energy density of the battery cell and the battery device.

[0013] In some embodiments, the first weld pool further extends along the axial direction to a portion located in the second segment, and the second weld pool further extends along the axial direction to a portion located in the first segment.

[0014] In this embodiment, the first welding molten pool and the second welding molten pool share more space in the axial direction, so that the height of the shared part of the two can be close to the total height of the first section and the second section. Further, the height of the main body in the axial direction can be reduced, and the energy density of the battery cell and the battery device can be improved.

[0015] In some embodiments, the first height H1 of the first section in the axial direction satisfies: 1.6 mm < H1 < 2.5 mm.

[0016] By setting the first height greater than 1.6 mm, the processing difficulty of the first section can be reduced, the electrical conductivity can be optimized, and good mechanical strength can be obtained. At the same time, the main body can have a certain height accordingly, preventing problems such as airtightness and battery cell liquid leakage caused by being welded through during welding. Setting the first height less than 2.5 mm can minimize the height of the main body as much as possible and improve the energy density of the battery cell.

[0017] In some embodiments, the second height H2 of the second section in the axial direction satisfies: 0.8 mm < H2 < 1.3 mm.

[0018] By setting the second height greater than 0.8 mm, the second section can have good mechanical strength, optimize the electrical conductivity, and prevent problems such as airtightness and battery cell liquid leakage caused by being welded through during welding. Setting the first height less than 1.3 mm can minimize the height of the main body as much as possible and improve the energy density of the battery cell.

[0019] In some embodiments, the first height H1 of the first section in the axial direction and the second height H2 of the second section in the axial direction satisfy: 2.5 mm < H1 + H2 < 3.8 mm.

[0020] By setting the sum of the first height and the second height greater than 2.5 mm, the main body can have good mechanical strength and optimize the electrical conductivity. It can be understood that if the height of the main body is too small, it is easy to be welded through during welding, resulting in problems such as airtightness and battery cell liquid leakage. By setting the total height of the main body greater than 2.5 mm, problems such as airtightness and battery cell liquid leakage can be improved. By setting the first height less than 3.8 mm, the height of the main body can be minimized as much as possible and the energy density of the battery cell can be improved.

[0021] In some embodiments, the first welding molten pool extends circumferentially along the main body to form a closed ring, and the second orthographic projection is located within the area enclosed by the first orthographic projection.

[0022] In this embodiment, from a top-down view, the first weld pool can be arranged around the second weld pool, so that the first orthographic projection of the first weld pool and the second orthographic projection of the second weld pool can be staggered, preventing the main body from being welded through due to the connection between the two during the welding process. In addition, the annular weld has a simple shape and structure, and the welding difficulty is low. At the same time, the annular first weld pool can increase the weld path length, thereby improving the connection strength and overcurrent capacity between the busbar and the main body.

[0023] In some embodiments, the first end of the main body is further provided with a first positioning part for welding positioning, the first positioning part being located within the area enclosed by the first weld pool.

[0024] By setting the first positioning part inside the area enclosed by the first welding pool, the space at the first end of the main body can be reasonably utilized to achieve welding positioning while improving the energy density of the battery cell.

[0025] In some embodiments, the second weld pool extends circumferentially along the body to form a closed ring, and the first orthographic projection is located within the area enclosed by the second orthographic projection.

[0026] In this embodiment, from a top-down view, the second weld pool can be arranged around the first weld pool, so that the first orthographic projection of the first weld pool and the second orthographic projection of the second weld pool can be staggered, preventing the main body from being welded through due to the connection between the two during the welding process. In addition, the annular weld has a simple shape and structure, and the welding difficulty is low. At the same time, the annular second weld pool can increase the weld path length, thereby improving the connection strength and overcurrent capacity between the adapter and the main body.

[0027] In some embodiments, the first end of the main body is further provided with a plurality of second positioning portions for welding positioning, the plurality of second positioning portions being disposed around the outside of the first weld pool.

[0028] By arranging multiple second positioning elements around the first welding pool at intervals, the space at the first end of the main body can be rationally utilized to achieve welding positioning while improving the energy density of the battery cell.

[0029] In some embodiments, the first weld pool and the second weld pool are arranged at intervals in a first direction, wherein the first direction is a direction perpendicular to the axial direction.

[0030] By arranging the first weld pool and the second weld pool at intervals along the first direction, space and conditions are provided for the first weld pool and the second weld pool to avoid each other in the first direction, effectively preventing the first weld pool and the second weld pool from connecting and causing the main body to be welded through.

[0031] In some embodiments, the first weld pool includes a first sub-welded pool; or, the first weld pool includes a plurality of first sub-welded pools that are spaced apart from each other.

[0032] In this embodiment, by setting one or more first sub-melt pools, the space of the main body on the plane parallel to the reference plane can be utilized as much as possible, the weld path length can be increased, thereby improving the connection strength between the busbar and the main body, and maximizing the overcurrent capacity between the two.

[0033] In some embodiments, the first sub-melt pool includes a linear melt pool extending in a straight line direction; or, the first sub-melt pool includes a circular melt pool extending in an arc direction; or, the first sub-melt pool includes a point-like melt pool; or, the first sub-melt pool includes a closed melt pool formed by connecting the first arc segment and the first straight line segment end to end.

[0034] All the above embodiments can achieve mutual avoidance between the first weld pool and the second weld pool in the first direction, effectively preventing the first weld pool and the second weld pool from connecting and causing the main body to be welded through.

[0035] In some embodiments, the second weld pool includes a second sub-weld pool; or, the second weld pool includes a plurality of second sub-weld pools that are spaced apart from each other.

[0036] In this embodiment, by setting one or more second sub-melt pools, the space of the main body on the plane parallel to the reference plane can be utilized as much as possible, the weld path length can be increased, thereby improving the connection strength between the adapter and the main body, and maximizing the overcurrent capacity between the two.

[0037] In some embodiments, the second sub-melt pool includes a linear melt pool extending in a straight line direction; or, the second sub-melt pool includes a circular melt pool extending in an arc direction; or, the second sub-melt pool includes a point-like melt pool; or, the second sub-melt pool includes a closed melt pool formed by connecting the second arc segment and the second straight line segment end to end.

[0038] All the above embodiments can achieve mutual avoidance between the first weld pool and the second weld pool in the first direction, effectively preventing the first weld pool and the second weld pool from connecting and causing the main body to be welded through.

[0039] In some embodiments, the electrode terminal further includes a connecting portion and an insulating portion, the insulating portion being sleeved outside the main body portion, one end of the connecting portion being embedded in the insulating portion, the other end of the connecting portion being connected to the housing, and at least a portion of the insulating portion being located between the main body portion and the connecting portion.

[0040] In this embodiment, the electrode terminals can be connected to the end cap through the connecting part, and the insulating part isolates the end cap and the main body, which can prevent short circuit between the two. At the same time, it can simplify the design of the main body. Unlike the related technology, which installs a riveting block on the outside of the electrode post and welds the busbar through the riveting block, it can further simplify the structure of the battery cell and improve the energy density of the battery cell.

[0041] An embodiment of the second aspect of this application provides a battery device comprising the battery cell of any of the above embodiments.

[0042] An embodiment of the third aspect of this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0043] An embodiment of the fourth aspect of this application provides an energy storage device, which includes the battery device in the above embodiments, and the energy storage device is used to store electrical energy.

[0044] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0045] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0046] Figure 1 This is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0047] Figure 2 This is an exploded view of the battery device according to some embodiments of this application;

[0048] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0049] Figure 4 This is a schematic diagram showing the connection between the end cap assembly, the busbar component, and the adapter.

[0050] Figure 5 for Figure 4 Schematic diagram of the cross section at point BB;

[0051] Figure 6 for Figure 5 Enlarged view of point C in the middle;

[0052] Figure 7 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application;

[0053] Figure 8 for Figure 7 Top view;

[0054] Figure 9 for Figure 8 Sectional view at point DD;

[0055] Figure 10 for Figure 9 Enlarged view of point E in the middle;

[0056] Figure 11 for Figure 10 A diagram showing the positional relationship between the first and second weld pools in the top view.

[0057] Figure 12 for Figure 9 Enlarged view of point F in the middle;

[0058] Figure 13 This is a schematic diagram showing the positions of the first weld pool and the second weld pool in other embodiments of this application;

[0059] Figure 14 This is a schematic diagram showing the positions of the first weld pool and the second weld pool in some embodiments of this application;

[0060] Figure 15 This is a schematic diagram of the end cap assembly according to other embodiments of this application;

[0061] Figure 16 for Figure 15 Top view;

[0062] Figure 17 for Figure 16 Sectional view at point GG;

[0063] Figure 18 for Figure 17 Enlarged view of point I in the middle;

[0064] Figure 19 for Figure 18 A diagram showing the positional relationship between the first and second weld pools in the top view.

[0065] Figure 20 This is a schematic diagram showing the positions of the first weld pool and the second weld pool in some embodiments of this application;

[0066] Figure 21 for Figure 20 A diagram showing the positional relationship between the first and second weld pools in the top view.

[0067] Figure 22 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0068] Figure 23 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0069] Figure 24 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0070] Figure 25 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0071] Figure 26 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0072] Figure 27 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0073] Figure 28 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0074] Figure 29 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0075] Figure 30 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application.

[0076] Explanation of reference numerals in the attached figures:

[0077] 1000 vehicles;

[0078] Battery unit 100, controller 200, motor 300;

[0079] Battery cell assembly 10, battery cell 11, main body 111, first section 1111, second section 1112, first positioning part 1113, second positioning part 1114, adapter 112, connecting part 113, insulation part 114.

[0080] Busbar component 120;

[0081] First weld pool 130, first sub-weld pool 131, first arc segment 132, first straight segment 133, second weld pool 140, second sub-weld pool 141, second arc segment 142, second straight segment 143;

[0082] 30 housing, 31 receiving cavity, 12 end cap assembly, 13 housing, 14 electrode assembly, 15 electrode body, 16 mounting hole, 17 end cap, 18 electrode terminal, 19 electrode tab;

[0083] Box 20, Part 1 21, Part 2 22. Detailed Implementation

[0084] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0085] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0086] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0087] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0088] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, "a and / or b" can represent three cases: a exists alone, a and b exist simultaneously, and b exists alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0089] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0090] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0091] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0092] Currently, the application of rechargeable batteries is becoming increasingly widespread, judging from market trends. They are not only used in energy storage systems for hydropower, thermal power, wind power, and solar power plants, but also extensively in various electronic devices, such as electric bicycles, electric motorcycles, and electric vehicles, as well as in military equipment and aerospace. As the application areas of rechargeable batteries continue to expand, the market demand is also constantly increasing.

[0093] In related technologies, for battery cells with a minimalist end cap design, both ends of the terminal post are welded to a busbar and an adapter plate, respectively. The busbar is used to connect multiple battery cells, and the adapter plate can be used to connect the main body to the electrode assembly. Specifically, the terminal post and the busbar are welded on the terminal post to form a terminal post-busbar weld pool, and the terminal post and the adapter plate are welded on the terminal post to form a terminal post-adapter plate weld pool.

[0094] To prevent the two weld pools from connecting and burning through the pole, the pole-bus weld pool is usually formed at the upper part of the pole along the height direction, while the pole-adapter weld pool is formed at the lower part of the pole. That is, the pole-bus weld pool and the pole-adapter weld pool do not share space in the height direction of the pole.

[0095] However, this design results in a relatively high electrode height, leading to a lower energy density in the battery.

[0096] To improve at least one of the above problems, embodiments of this application provide a battery cell, a battery device, an electrical device, and an energy storage device. The battery cell includes a housing, an electrode assembly, and electrode terminals. The housing has a receiving cavity. The electrode assembly is received in the receiving cavity and includes an electrode body and a tab disposed at one end of the electrode body. The electrode terminals are disposed in the housing and include a body portion. By providing a first weld pool for electrical connection with a busbar component at the first end of the main body and a second weld pool for electrical connection with a tab at the second end of the main body, and using a plane perpendicular to the axial direction as a reference plane, the first orthographic projection of the first weld pool on the reference plane and the second orthographic projection of the second weld pool on the reference plane are offset from each other, and the third orthographic projection of the first weld pool on the axial direction and the fourth orthographic projection of the second weld pool on the axial direction at least partially overlap. This allows the first and second weld pools to share a portion of the height space, reducing the height of the main body and increasing the energy density of the battery cell and battery device. At the same time, since the orthographic projections of the reference planes of the first and second weld pools are offset from each other, the first and second weld pools will not be connected to each other, improving the problem of the main body being easily welded through.

[0097] The technical solutions described in the embodiments of this application are applicable to battery cells, battery devices containing battery cells, electrical devices using battery devices, and energy storage devices.

[0098] The energy storage device utilizing battery devices as a power source in this application embodiment includes one or more battery clusters to enhance the voltage and capacity of the energy storage device. A battery cluster may include multiple battery devices, which are connected in series via a busbar to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0099] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, an energy storage device can store electrical energy during off-peak hours and provide power to relevant users or electrical devices during peak hours. The energy storage system provided in this application embodiment can be any power system that requires energy storage devices. As an example, the energy storage device is an energy storage container or an energy storage cabinet.

[0100] In this application embodiment, the power-consuming device using a battery as a power source can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0101] It should be understood that the technical solutions described in the embodiments of this application are not limited to the energy storage devices and electrical devices described above, but can also be applied to all battery devices including housings and electrical devices using battery devices, thereby improving the energy density of individual battery cells and battery devices. However, for the sake of brevity, the following embodiments will use a vehicle as an example of an electrical device for illustration.

[0102] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0103] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0104] Please refer to Figure 2 , Figure 2 This is an exploded structural diagram of a battery provided in some embodiments of this application.

[0105] The battery device 100 mentioned in the embodiments of this application may include one or more battery cell assemblies 10 for providing voltage and capacity. The battery cell assembly 10 may include multiple battery cells 11, which are connected in series, parallel, or mixed connection via a busbar.

[0106] In some embodiments, the battery cell assembly 10 is typically formed by arranging a plurality of battery cells 11.

[0107] As an example, the battery cell assembly 10 can be a battery module, which is formed by arranging and fixing multiple battery cells 11 together to form an independent module. As an example, the battery module can be formed by bundling multiple battery cells 11 together with cable ties.

[0108] In some embodiments, such as Figure 2 As shown, the battery device 100 can be a battery pack, which includes a housing 20 and one or more individual battery cells 10, with the individual battery cells 10 housed within the housing 20. The housing 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or a complex three-dimensional structure composed of combinations of simple cuboids, cylinders, or spheres. The material of the housing 20 can be an alloy such as aluminum alloy or iron alloy, a polymer such as polycarbonate or polyisocyanurate foam, or a composite material such as glass fiber and epoxy resin.

[0109] As an example, the battery cell assembly 10 can be a battery module, and the battery cell assembly 10 can be housed in the housing 20 by fixing the battery module in the housing 20.

[0110] As an example, the battery cell assembly 10 can also be housed in the housing 20 by directly fixing multiple battery cells 11 to the housing 20.

[0111] As an example, the housing 20 may include a first part 21 and a second part 22. The first part 21 and the second part 22 are fastened together to form a closed space inside the housing 20 to house the battery cell assembly 10. Here, "closed" refers to covering or closing, and can be either non-sealed or sealed to prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell 11. The first part 21 may be a top cover or a bottom plate.

[0112] As an example, the housing 20 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 20 forms an enclosed space to house the battery cell assembly 10.

[0113] In some embodiments, the housing 20 may be part of the vehicle's chassis structure. For example, a portion of the housing 20 may be at least a portion of the vehicle's floor, or a portion of the housing 20 may be at least a portion of the vehicle's crossbeams and longitudinal beams.

[0114] The battery cell 11 provided in the embodiments of this application can be a secondary battery. A secondary battery refers to a battery cell 11 that can be used again after being discharged by recharging to activate the active material.

[0115] The battery cell 11 can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0116] Please refer to Figure 3 , Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. The battery cell 11 refers to the smallest unit that makes up the battery. For example... Figure 3 The battery cell 11 includes a housing 30, an electrode assembly 14, and other functional components.

[0117] The outer casing 30 includes an end cap assembly 12 and a housing 13. The end cap assembly 12 includes an end cap 17 and an insulating connector disposed inside the end cap. The end cap assembly 12 and the housing 13 form a receiving cavity 31. The end cap assembly 12 is a component that covers the opening of the housing 13 to isolate the internal environment of the battery cell 11 from the external environment. Indiscriminately, the shape of the end cap assembly 12 can be adapted to the shape of the housing 13 to fit the housing 13. In some embodiments, the end cap 17 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 17 is less prone to deformation under pressure and impact, enabling the battery cell 11 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 18 can be provided on the end cap 17. The electrode terminal 18 includes a main body 111, which can be electrically connected to the electrode assembly 14 for outputting or inputting electrical energy from the battery cell 11. In some embodiments, the end cap 17 may also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 11 reaches a threshold. The end cap 17 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, or plastic. An insulating connector can be used to isolate the electrical connection components within the housing 13 from the end cap 17 to reduce the risk of short circuits. For example, the insulating connector can be made of plastic, rubber, etc. Additionally, an insulating portion 114 can be sleeved on the outside of the main body 111, and the insulating portion 114 is connected to the end cap 17, thereby isolating the end cap 17 from the main body 111 to reduce the possibility of short circuits. For example, the insulating portion 114 can be made of plastic, rubber, etc.

[0118] The housing 13 is a component used to cooperate with the end cap assembly 12 to form the internal environment of the battery cell 11. This internal environment can accommodate the electrode assembly 14, electrolyte, and other components. The housing 13 and the end cap assembly 12 can be independent components. An opening can be provided on the housing 13, and the end cap assembly 12 closes the opening to form the internal environment of the battery cell 11. Alternatively, the end cap assembly 12 and the housing 13 can be integrated. Specifically, the end cap assembly 12 and the housing 13 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 13, the end cap assembly 12 closes the housing 13. The housing 13 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 13 can be determined according to the specific shape and size of the electrode assembly 14. The housing 13 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0119] Electrode assembly 14 is the component in the battery cell 11 where the electrochemical reaction occurs. The housing 13 may contain one or more electrode assemblies 14. Electrode assembly 14 includes an electrode body 15 and tabs 19. The electrode body 15 can be formed by winding or stacking electrode sheets (including positive and negative electrode sheets) and a separator. The electrode sheets may include a current collector and an active material disposed on the surface of the current collector. The tabs 19 can be disposed at one end of the electrode body 15; for example, the tabs 19 can extend outward from one end of the current collector, and their surface may not be provided with active material.

[0120] Figure 4 This is a schematic diagram showing the connection between the end cap assembly, the busbar component, and the adapter. Figure 5 for Figure 4 Cross-sectional view at point BB. Figure 6 for Figure 5 A magnified view of point C. Please refer to... Figures 3 to 6 This application provides a battery cell 11, including: a housing 30, an electrode assembly 14, and an electrode terminal 18. The housing 30 has a receiving cavity 31; the electrode assembly 14 is received in the receiving cavity 31, and the electrode assembly 14 includes an electrode body 15 and a tab 19 disposed at one end of the electrode body 15; the electrode terminal 18 is disposed on the housing 30, and the electrode terminal 18 includes a main body portion 111. A first end of the main body portion 111 along the axial direction X is used for electrical connection with a current collector 120, and a second end of the main body portion 111 along the axial direction X is electrically connected to the tab 19. The first end of the main body portion 111 has a first weld pool 130 for electrical connection with the current collector 120, and the second end of the main body portion 111 has a second weld pool 140 for electrical connection with the tab 19.

[0121] With a plane perpendicular to the axial direction X as the reference plane A, the first orthographic projection of the first weld pool 130 on the reference plane A and the second orthographic projection of the second weld pool 140 on the reference plane A are offset from each other, and the third orthographic projection of the first weld pool 130 on the axial direction X and the fourth orthographic projection of the second weld pool 140 on the axial direction X at least partially coincide.

[0122] The busbar component 120 can be a conductive component made of conductive material, such as copper or aluminum. The busbar component can be a rigid component that is not easily bent, or a flexible component that can be bent; the choice depends on the specific circumstances. Figure 4 The diagram shows a busbar assembly 12 connecting two battery cells to an end cap assembly 12, thereby enabling the connection of the two battery cells.

[0123] like Figure 5 and Figure 6 The battery cell 11 may include a housing 30, an electrode assembly 14, and electrode terminals 18. The housing 30 may include an end cap assembly 12 and a shell 13. The shell 13 has an opening, and the end cap assembly 12 can cover the opening so that the two together form a receiving cavity 31. The electrode assembly 14 can be accommodated in the receiving cavity 31. The electrode assembly 14 may include an electrode body 15 and a tab 19 connected to one end of the electrode body 15. The electrode body 15 may be formed by winding or stacking electrode sheets (including positive electrode sheets and negative electrode sheets) and a separator. The electrode sheet may include a current collector and an active material disposed on the surface of the current collector. The tab 19 may be disposed at one end of the electrode body 15. For example, the tab 19 may extend outward from one end of the current collector, and its surface may not be provided with active material.

[0124] Electrode terminals 18 may be disposed on the end cap assembly 12 of the housing 30, for example, they may pass through the end cap assembly 12. Electrode terminals 18 may include a body portion 111. It is understood that the body portion 111 may be used to realize electrical connections between the inside and outside of the battery cell 11.

[0125] Figure 7 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application. Figure 8 for Figure 7 Top view, Figure 9 for Figure 8 Sectional view at DD in the middle. Figure 10 for Figure 9 An enlarged view of point E in the middle. Figure 11 for Figure 10 The diagram showing the positional relationship between the first and second weld pools in the top view.

[0126] I understand, please refer to Figures 7 to 11 The main body 111 can be as follows: Figure 10 The embodiment shown is made of the same material; in other embodiments, it may also be made of two materials, or of course, more materials (such as...). Figure 6 (The two materials mentioned are not restricted here.)

[0127] The axial direction of the main body 111 can be the direction of the straight line indicated by X in the figure. It can be understood that the axial direction of the main body 111 can also be the axial direction of the electrode terminal 18. The main body 111 can be cylindrical, or it can be square, rectangular, elliptical, or other shapes. The axial direction can refer to the direction of the centerline of the main body 111, which can pass through the geometric center of the main body 111 and be perpendicular to the plane where the end cap 17 is located. The first end of the main body 111 can be the end of the main body 111 facing the outer side of the battery cell 11, for example... Figure 10 The upper end of the main body 111 in the axial direction X can be the end of the main body 111 facing the inner side of the battery cell 11, for example, Figure 10 The lower end of the central axis direction X. The axial direction X of the main body 111 can be defined as the height direction of the main body.

[0128] In this embodiment, the busbar component 120 can be electrically connected to the first end of the main body 111. This electrical connection can be a direct electrical connection or an indirect electrical connection. For example, the first end of the main body 111 can be directly welded to the busbar component 120 to achieve an electrical connection, or the first end of the main body 111 can be indirectly electrically connected to the busbar component 120 by welding other components. Both the direct and indirect electrical connection methods can achieve the interconnection between the battery cells 11.

[0129] Additionally, the tab 19 can be electrically connected to the second end of the main body 111. This electrical connection can be direct or indirect. For example, the main body 111 can be directly soldered to the tab 19 to achieve an electrical connection. In some embodiments, the electrode terminal 18 may further include an adapter 112, the second end of the main body 111 can be directly soldered to the adapter 112, and the adapter 112 can also be soldered to the tab 19, thereby enabling the main body 111 to achieve an indirect electrical connection with the tab 19 via the adapter 112. Both the direct and indirect electrical connection methods described above can achieve an electrical connection between the main body 111 and the electrode assembly 14.

[0130] The adapter 112 can be made of a conductive material such as copper or aluminum. Alternatively, the adapter 112 can be made of a flexible material or a rigid material. The welding method described above can be one or more of the following: laser welding, ultrasonic welding, resistance welding, brazing, tungsten inert gas welding, or metallic inert gas welding.

[0131] For ease of explanation, the following description will take the example of welding the first end of the main body 111 to the busbar component 120 and welding the second end of the main body 111 to the adapter 112.

[0132] It is understood that during the welding process, the base material and filler material melt at high temperatures to form a liquid metal region, which is called the weld pool. During the welding of the main body 111 to the busbar 120, the material of the main body 111 melts to form a liquid metal region, which solidifies to form the first weld pool 130. Furthermore, during the welding of the main body 111 to the adapter 112, the material of the main body 111 melts to form a liquid metal region, which solidifies to form the second weld pool 140.

[0133] Please refer to Figure 10 and Figure 11 , Figure 10 A cross-sectional schematic diagram of the first weld pool 130 and the second weld pool 140 is shown. Figure 11 It shows Figure 10 The positional relationship between the first weld pool 130 and the second weld pool 140 in the top view (downward along the axis) can be understood as follows: Figure 11 The shape of the first weld pool 130 can represent the shape of the first orthographic projection of the first weld pool 130 on the reference plane A, and the shape of the second weld pool 140 can represent the shape of the second orthographic projection of the second weld pool 140 on the reference plane A. Figure 11 It can be seen that the first and second orthographic projections are staggered, meaning they do not intersect or overlap. In this embodiment, the main body 111 can be enlarged to maximize its size in the plane perpendicular to the axial direction X, thereby increasing the dimensions of the first and second welding pools along the length of the battery cell 11. Figure 8 (left and right directions) and width direction ( Figure 8 Provide as much clearance as possible in the vertical direction, so that the first orthographic projection and the second orthographic projection are staggered.

[0134] Additionally, refer to Figure 10The third orthographic projection of the first weld pool 130 on the axial direction X can be understood as drawing perpendicular lines from each point of the first weld pool 130 to the position of the axial direction X, thus obtaining a line segment (third orthographic projection) on the axial direction X. Similarly, the fourth orthographic projection of the second weld pool 140 on the axial direction X can be understood as drawing perpendicular lines from each point of the second weld pool 140 to the position of the axial direction X, thus obtaining a line segment (fourth orthographic projection) on the axial direction X. It can be understood that the third and fourth orthographic projections partially overlap. In the figure, L1 represents the space occupied by the third orthographic projection on the axial direction, and L2 represents the space occupied by the fourth orthographic projection on the axial direction. They share a portion of space L3 on the axial direction, meaning L1 and L2 partially overlap in the X direction, thus allowing the first weld pool 130 and the second weld pool 140 to share a portion of space on the axial direction X.

[0135] It is understood that in related technologies, the electrode post, the electrode post-transfer piece welding pool, and the electrode post-bus welding pool do not share the same height space. However, in this embodiment, by partially overlapping the third and fourth orthographic projections, the first and second welding pools can share a portion of the space along the axial direction. This compresses the height of the main body along the axial direction, allowing the battery cell to store more energy in the same volume, thereby increasing the energy density of the battery cell and the battery device. Simultaneously, by staggering the first and second orthographic projections, the first and second welding pools will not connect (interfere), thus improving the phenomenon of weld penetration in the main body. This mitigates the airtightness failure of the main body caused by weld penetration, preventing leakage from the battery cell.

[0136] Figure 12 for Figure 9 Please refer to the enlarged diagram at point F. Figure 12 According to some embodiments of this application, the electrode terminal 18 includes a first electrode terminal, the main body 111 of the first electrode terminal includes a first segment 1111 and a second segment 1112, the second segment 1112 is connected to one end of the first segment 1111 along the axial direction X, the first segment 1111 is provided with a first weld pool 130, the second segment 1112 is provided with a second weld pool 140, and the constituent material of the first segment 1111 is different from the constituent material of the second segment 1112.

[0137] It is understood that the electrode terminal may include a first electrode terminal or a second electrode terminal. In some embodiments, the first electrode terminal may be a negative terminal, and the main body 111 of the negative terminal may be made of a composite material.

[0138] Specifically, the main body 111 of the negative terminal may include a first segment 1111 and a second segment 1112 connected sequentially along the axial direction X. It is understood that the first segment 1111 can be used to weld to the busbar component 120, thereby forming a first weld pool 130 in the first segment 1111. The second segment 1112 can be used to weld to the adapter 112, thereby forming a second weld pool 140 in the second segment 1112. The first end of the main body is the end of the first segment 1111 facing away from the second segment 1112, and the second end of the main body 111 is the end of the second segment 1112 facing away from the first segment 1111.

[0139] The first segment 1111 can be made of conductive materials such as copper, aluminum, and iron, and the second segment 1112 can also be made of conductive materials such as copper, aluminum, and iron. However, the materials that make up the first segment 1111 are different from the materials that make up the second segment 1112.

[0140] In one specific embodiment, the first segment 1111 can be made of aluminum and the second segment 1112 can be made of copper, that is, the main body 111 can be a composite pole made of different materials.

[0141] It is understandable that the adapter is typically made of copper, and the busbar can be made of aluminum. Since the welding strength of dissimilar metals is difficult to guarantee, to ensure the connection strength between the adapter and the second segment 1112, and between the busbar and the first segment 1111, the first segment 1111 can be made of the same metal as the busbar, such as aluminum, and the second segment 1112 can be made of the same metal as the adapter, such as copper. This results in a composite pole made of composite materials. Furthermore, the composite material body 111 can improve the connection strength between the body, the busbar, and the adapter.

[0142] Of course, in other embodiments, the first segment 1111 may also be made of copper, and the second segment 1112 may be made of aluminum. It is understood that in this embodiment, the interface between the first segment 1111 and the second segment 1112 may be an inclined surface or a curved surface, so that the first weld pool 130 located in the first segment 1111 and the second weld pool 140 located in the second segment 1112 may share a portion of the space in the axial direction X.

[0143] In this embodiment, the main body of the negative terminal can be a composite pole made of composite material, while the main body of the positive terminal can be made of the same material. For example... Figure 9The two main body parts in the end cap 17 are made of a single material (the main body part of the positive terminal) and a composite pole made of multiple materials (the main body part of the negative terminal). This application embodiment is not limited to this. In other embodiments, the main body parts of the negative terminal and the positive terminal on the end cap can both be made of composite materials or both can be made of a single material. Of course, when both are made of composite materials, the quantity and type of composite materials used in the two main body parts can also be set to be the same or different depending on the situation.

[0144] In this embodiment, by using composite materials to construct the main body, the connection strength between the main body and the busbar and adapter can be improved.

[0145] Continue to refer to Figure 12 According to some embodiments of this application, the first weld pool 130 also extends along the axial direction X to a portion located in the second segment 1112.

[0146] Understandable. Figure 12 In this configuration, the second weld pool 140 can all be located within the second segment 1112. The first weld pool 130 can extend downward along the axial direction X to pass through the interface between the first segment 1111 and the second segment 1112, thereby allowing a portion of it to be located within the second segment 1112.

[0147] By placing a portion of the first welding pool 130 in the second section 1112, the first welding pool 130 and the second welding pool 140 can share more height space along the axial direction, so that the height of the shared portion can be close to the height of the second section, further reducing the height of the main body in the axial direction and increasing the energy density of the battery cell and battery device.

[0148] Figure 13 For schematic diagrams showing the positions of the first weld pool and the second weld pool in other embodiments of this application, please refer to... Figure 13 According to some embodiments of this application, the second weld pool 140 also extends along the axial direction to a portion located in the first segment 1111.

[0149] Understandable. Figure 13 In this process, the first weld pool 130 can be located entirely within the first segment 1111. The second weld pool 140 can extend upward along the axial direction X to pass through the interface between the first segment 1111 and the second segment 1112, thereby allowing a portion of it to be located within the first segment 1111.

[0150] By setting a portion of the second welding pool 140 in the first segment 1111, the first welding pool 130 and the second welding pool 140 can share more height space along the axial direction, so that the height of the shared portion can be close to the height of the first segment, further reducing the height of the main body in the axial direction and increasing the energy density of the battery cell and battery device.

[0151] Figure 14 For a schematic diagram showing the positions of the first weld pool and the second weld pool in some embodiments of this application, please refer to... Figure 14 According to some embodiments of this application, the first weld pool 130 further extends along the axial direction X to be partially located in the second segment 1112, and the second weld pool 140 further extends along the axial direction to be partially located in the first segment 1111.

[0152] In this embodiment, the first weld pool 130 can extend downward along the axial direction X to pass through the interface between the first segment 1111 and the second segment 1112, so that a portion of it can be located in the second segment 1112. The second weld pool 140 can extend upward along the axial direction X to pass through the interface between the first segment 1111 and the second segment 1112, so that a portion of it can be located in the first segment 1111.

[0153] By placing a portion of the first welding pool 130 in the second section 1112 and a portion of the second welding pool 140 in the first section 1111, the first welding pool 130 and the second welding pool 140 can share more space along the axial direction, so that the height of the shared portion can be close to the total height of the first and second sections, further reducing the height of the main body in the axial direction and increasing the energy density of the battery cell and battery device.

[0154] Understandably, in related technologies, the electrode post in the minimalist end cap design can be an Al (aluminum)-Cu (copper) composite electrode post. The Al block is welded to the busbar, and the Cu block is welded to the adapter plate. The total height of the electrode post is generally 3.8mm, with the Al block being 2.5mm thick and the Cu block being 1.3mm thick. The electrode post-busbar weld pool formed by welding the electrode post to the busbar is confined within the Al block, and the electrode post-adapter plate weld pool formed by welding the electrode post to the adapter plate is also confined within the Cu block.

[0155] It can be understood that in the related art, considering the presence of pores at the tip of the welding molten pool, in order to avoid interference between two molten pools (i.e., their connection and communication), the thicknesses of the Al block and the Cu block are increased. It is required that the molten pool of the pole - adapter plate and the molten pool of the pole - busbar do not cross the Al - Cu composite interface (the composite interface is a plane perpendicular to the axis direction of the pole), to prevent the busbar from directly welding through the pole during busbar welding, causing the two molten pools to communicate. However, this results in a relatively large height of the pole and a low energy density of the battery cell.

[0156] And in the above Figures 12 to 14 shown embodiment, by passing the first welding molten pool and / or the second welding molten pool through the interface between the first section and the second section, the height of the main body can be greatly reduced, and the energy density of the battery cell can be further improved.

[0157] As Figure 12 shown, according to some embodiments of the present application, the first height H1 of the first section 1111 along the axis direction satisfies: 1.6 mm < H1 < 2.5 mm.

[0158] In this embodiment, the first section 1111 can be made of aluminum. The first height H1 can be 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm or 2.4 mm, etc.

[0159] In some embodiments, 1.8 mm < H1 < 2.5 mm, or, 1.6 mm < H1 < 2.3 mm, or, 1.8 mm < H1 < 2.3 mm, or, 1.9 mm < H1 < 2.1 mm, etc.

[0160] By setting the first height greater than 1.6 mm, the processing difficulty of the first section can be reduced, the electrical conductivity can be optimized, and good mechanical strength can be achieved. At the same time, the main body can have a certain height accordingly, preventing problems such as airtightness and battery cell leakage caused by being welded through during welding. Setting the first height less than 2.5 mm can minimize the height of the main body 111 as much as possible and improve the energy density of the battery cell.

[0161] As Figure 12 shown, according to some embodiments of the present application, the second height H2 of the second section 1112 along the axis direction satisfies: 0.8 mm < H2 < 1.3 mm.

[0162] In this embodiment, the second section 1112 can be made of copper. The second height H2 can be 0.9 mm, 0.95 mm, 1 mm, 1.05 mm, 1.1 mm, 1.15 mm, 1.2 mm or 1.25 mm, etc.

[0163] In some embodiments, 0.9 mm < H2 < 1.3 mm, or, 0.8 mm < H2 < 1.2 mm, or, 0.9 mm < H2 < 1.2 mm, or, 0.9 mm < H2 < 1.1 mm, etc.

[0164] By setting the second height greater than 0.8 mm, the second segment can have good mechanical strength, optimize the electrical conductivity, and prevent problems such as airtightness and leakage of the battery cell caused by being penetrated during welding. Setting the first height less than 1.3 mm can minimize the height of the main body 111 as much as possible and improve the energy density of the battery cell.

[0165] As Figure 12 shown, according to some embodiments of the present application, the following is satisfied between the first height H1 of the first segment 1111 along the axial direction and the second height H2 of the second segment 1112 along the axial direction: 2.5 mm < H1 + H2 < 3.8 mm.

[0166] In this embodiment, the interface between the first segment 1111 and the second segment 1112 can be a plane perpendicular to the axial direction X, so that the shapes of the first segment 1111 and the second segment 1112 can be relatively regular, facilitating processing and forming.

[0167] In addition, H1 + H2 can be used to represent the total height of the main body 111 along the axial direction. There can be various values for H1 + H2. For example, it can be 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, etc.

[0168] In some embodiments, 2.8 mm < H1 + H2 < 3.8 mm, or, 2.5 mm < H1 + H2 < 3.6 mm, or, 2.8 mm < H1 + H2 < 3.6 mm, or, 2.9 mm < H1 + H2 < 3.5 mm, etc.

[0169] By setting the sum of the first height and the second height greater than 2.5 mm, the main body can have good mechanical strength and optimize the electrical conductivity. It can be understood that if the height of the main body is too small, it is easy to be penetrated during welding, resulting in problems such as airtightness and leakage of the battery cell. By setting the total height of the main body greater than 2.5 mm, problems such as airtightness and leakage of the battery cell can be improved. By setting the first height less than 3.8 mm, the height of the main body 111 can be minimized as much as possible and the energy density of the battery cell can be improved.

[0170] As Figure 11As shown, according to some embodiments of this application, the first weld pool 130 extends circumferentially along the main body 111 in a closed ring shape, and the second orthographic projection is located within the area enclosed by the first orthographic projection.

[0171] Understandable. Figure 11 The diagram shows the positional relationship between the first weld pool 130 and the second weld pool 140 from a top-view angle along the axial direction X. Since the first and second orthographic projections are also projections onto the reference plane A along the axial direction X, it can be understood that... Figure 11 The position of the first weld pool 130 can represent the position of the first orthographic projection, and the position of the second weld pool 140 can also represent the position of the second orthographic projection.

[0172] in addition, Figure 10 , Figures 12 to 14 From a top-down view, the positional relationship between the first weld pool 130 and the second weld pool 140 can be seen as follows: Figure 11 As shown. The circumferential direction of the main body can be the direction surrounding the axis of the main body.

[0173] Depend on Figure 11 It can be seen that the first weld pool 130 is a closed-end ring, that is, the first orthographic projection is a closed-end ring, which is understandable. Figure 11 The image shown is circular, but in other embodiments, it can be an elliptical ring, a rectangular ring, or a square ring, etc., as long as it is closed at both ends. The second weld pool and the second orthographic projection can be in various shapes such as dot, ring, or line.

[0174] The second orthographic projection can be located within the area enclosed by the first orthographic projection, that is, the second orthographic projection can be located within the annular space of the first orthographic projection.

[0175] In this embodiment, from a top-down view, the first weld pool can be arranged around the second weld pool, so that the first orthographic projection of the first weld pool and the second orthographic projection of the second weld pool can be staggered, preventing the main body from being welded through due to the connection between the two during the welding process. In addition, the annular weld has a simple shape and structure, and the welding difficulty is low. At the same time, the annular first weld pool can increase the weld path length, thereby improving the connection strength and overcurrent capacity between the busbar and the main body.

[0176] Please refer to Figure 7 , Figure 8 and Figure 10 According to some embodiments of this application, the first end of the main body 111 is further provided with a first positioning part 1113 for welding positioning, and the first positioning part 1113 is located in the area enclosed by the first weld pool 130.

[0177] It is understandable that welding equipment is required during the welding process between the battery cell and the busbar component. The gripper of the welding equipment can scan the battery cell to identify the first positioning part 1113. After identifying the first positioning part 1113, the clamping position of the gripper can be determined, thereby clamping the busbar component 120 at a specific position on the battery cell and then welding is achieved, which is beneficial to the accuracy of welding positioning.

[0178] Specifically, the first positioning part 1113 can be disposed at the center of the main body. The structure of the first positioning part 1113 can be various, for example, it can be as follows: Figure 10 The diagram shows a hole-like structure, which can be round, square, conical, or in various other shapes.

[0179] In this embodiment, the first positioning part 1113 can be located inside the first weld pool. That is, the first orthographic projection is annular, and the orthographic projection of the first positioning part 1113 on the reference plane A is located within the first orthographic projection.

[0180] By setting the first positioning part 1113 inside the area enclosed by the first welding pool, the space at the first end of the main body can be reasonably utilized to achieve welding positioning while improving the energy density of the battery cell.

[0181] Figure 15 This is a schematic diagram of the end cap assembly according to other embodiments of this application. Figure 16 for Figure 15 Top view, Figure 17 for Figure 16 Sectional view at point GG. Figure 18 for Figure 17 Enlarged diagram at point I in the middle. Figure 19 for Figure 18 The diagram shows the positional relationship between the first and second weld pools in the top view. Please refer to... Figures 15 to 19 According to some embodiments of this application, the second weld pool 140 extends circumferentially along the main body 111 in a closed ring shape, and the first orthographic projection is located within the area enclosed by the second orthographic projection.

[0182] Understandable. Figure 19 The diagram shows the positional relationship between the first weld pool 130 and the second weld pool 140 from a top-view angle along the axial direction X. Since the first and second orthographic projections are also projections onto the reference plane A along the axial direction X, it can be understood that... Figure 19 The position of the first weld pool 130 can also represent the position of the first orthographic projection, and the position of the second weld pool 140 can also represent the position of the second orthographic projection.

[0183] Depend on Figure 19It can be seen that the second weld pool 140 is a closed-end annular shape, that is, the second orthographic projection is a closed-end annular shape, which is understandable. Figure 19 The image is shown as a ring, but in other embodiments, it can be an elliptical ring, a rectangular ring, or a square ring, etc., as long as it is closed at both ends. The first weld pool 130 and the first orthographic projection can be various shapes such as dot, ring, or line.

[0184] The first orthographic projection can be located within the area enclosed by the second orthographic projection, that is, the first orthographic projection can be located within the annular space of the second orthographic projection.

[0185] In this embodiment, from a top-down view, the second weld pool can be arranged around the first weld pool, so that the first orthographic projection of the first weld pool and the second orthographic projection of the second weld pool can be staggered, preventing the main body from being welded through due to the connection between the two during the welding process. In addition, the annular weld has a simple shape and structure, and the welding difficulty is low. At the same time, the annular second weld pool can increase the weld path length, thereby improving the connection strength and overcurrent capacity between the adapter and the main body.

[0186] Please refer to Figure 15 , Figure 16 and Figure 18 According to some embodiments of this application, the first end of the main body 111 is further provided with a plurality of second positioning parts 1114 for welding positioning, and the plurality of second positioning parts 1114 are disposed around the first welding molten pool 130.

[0187] In this embodiment, the grippers of the welding equipment can scan the battery cell to identify the second positioning part 1114. After identifying the second positioning part 1114, the gripping position of the grippers can be determined, thereby clamping the busbar component 120 at a specific position of the battery cell and then performing welding, which is beneficial to the accuracy of welding positioning.

[0188] The structure of the second positioning part 1114 can be varied, for example, it can be as follows: Figure 18 The diagram shows a hole-like structure, which can be round, square, conical, or in various other shapes.

[0189] In this embodiment, there may be multiple second positioning parts 1114, and the multiple second positioning parts 1114 are arranged at intervals around the first welding pool 130. For example Figure 16 The second positioning part 1114 can be a strip-shaped hole, and multiple second positioning parts 1114 can be equally spaced along the circumference of the first welding molten pool 130 with the first welding molten pool 130 as the center.

[0190] Understandable. Figure 16The image shows four second positioning portions 1114 (four embossed lines). In other embodiments, the second positioning portions 1114 may be two, three, five, six, seven, eight, nine or more.

[0191] In addition, in this embodiment, Figure 18 The diagram shows a first weld pool 130 extending from a first segment 1111 to partially within a second segment 1112, and a second weld pool 140 extending from the second segment 1112 to partially within the first segment 1111. However, in other embodiments, the first weld pool 130 may be entirely within the first segment 1111, and the second weld pool 140 may extend from the second segment 1112 to partially within the first segment 1111. Alternatively, the first weld pool 130 may extend from the first segment 1111 to partially within the second segment 1112, and the second weld pool 140 may be entirely within the second segment 1112.

[0192] By arranging multiple second positioning parts 1114 at intervals around the first welding pool 130, the space at the first end of the main body can be reasonably utilized to achieve welding positioning while improving the energy density of the battery cell.

[0193] Figure 20 This is a schematic diagram showing the positions of the first weld pool and the second weld pool in some embodiments of this application. Figure 21 for Figure 20 Please refer to the diagram showing the positional relationship between the first and second weld pools in the top view. Figure 20 and Figure 21 According to some embodiments of this application, the first weld pool 130 and the second weld pool 140 are spaced apart in a first direction Y, wherein the first direction Y is a direction perpendicular to the axial direction X.

[0194] It is understandable that the first direction can be the length direction of the battery cell. Figure 16 The left and right directions in the middle can also be the width direction of the battery cell. Figure 16 (Up and down directions in the middle).

[0195] In this embodiment, the first weld pool 130 and the second weld pool 140 can be spaced apart along the first direction, for example... Figure 20 In the process, the first weld pool 130 is located on the right side of the axial direction X, and the second weld pool 140 is located on the left side of the axial direction X.

[0196] Figure 22 For a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application, please refer to... Figure 22 In some embodiments, the first weld pool 130 may also be located on the left side and the second weld pool 140 may be located on the right side.

[0197] In addition, this embodiment can be used in main body parts of various shapes, such as cylindrical main body parts, rectangular main body parts, and of course, this embodiment can also be used in elliptical main body parts. In this case, the first direction Y can be the major axis direction of the elliptical main body part, so that the space of the main body part in the major axis direction can be better utilized, and the distance between the first weld pool and the second weld pool can be maximized, effectively preventing the first weld pool and the second weld pool from connecting and causing the main body part to be welded through.

[0198] By arranging the first weld pool 130 and the second weld pool 140 at intervals along the first direction, space and conditions are provided for the first weld pool and the second weld pool to avoid each other in the first direction, effectively preventing the first weld pool and the second weld pool from connecting and causing the main body to be welded through.

[0199] Figure 23 For a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application, please refer to... Figures 21 to 23 According to some embodiments of this application, the first weld pool 130 includes a first sub-weld pool 131; or, the first weld pool 130 includes a plurality of first sub-weld pools 131 that are spaced apart from each other.

[0200] In this embodiment, the first weld pool 130 may include one or more first sub-welded pools 131 formed by welding. It is understood that the number of first sub-welded pools 131 can be 1, 2, 3, 4, 5, 6, etc., and can be set according to actual conditions. Figure 23 When there are multiple first sub-melt pools 131, these first sub-melt pools 131 can be arranged separately from each other, that is, they are not connected to each other. In addition, the shapes of the individual first sub-melt pools 131 can be the same or different.

[0201] In some embodiments, please refer to Figure 21 and Figure 22 The first weld pool 130 includes a first sub-weld pool 131.

[0202] In other embodiments, please refer to Figure 23 The first welding pool 130 includes two first sub-melt pools 131, which are spaced apart.

[0203] In this embodiment, by setting one or more first sub-melt pools, the space of the main body on the plane parallel to the reference mina can be utilized as much as possible to increase the weld path length, thereby improving the connection strength between the busbar and the main body and maximizing the overcurrent capacity between them.

[0204] Figure 24 For a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application, please refer to... Figure 21 , Figure 22 and 24 According to some embodiments of this application, the second weld pool 140 includes a second sub-weld pool 141. Alternatively, the second weld pool 140 includes a plurality of mutually spaced second sub-weld pools 141.

[0205] In this embodiment, the second weld pool 140 may include one or more second sub-welded pools 141 formed by welding. It is understood that the number of second sub-welded pools 141 can be 1, 2, 3, 4, 5, 6, etc., and can be set according to actual conditions. When there are multiple second sub-welded pools 141, these second sub-welded pools 141 can be separated from each other, that is, they are not connected to each other. Furthermore, the shapes of each of the multiple second sub-welded pools 141 can be the same or different. In some embodiments, the shapes of the first sub-welded pool 131 and the second sub-welded pool 141 can be the same or different.

[0206] In some embodiments, please refer to Figure 21 and Figure 22 The second weld pool 140 includes a second sub-weld pool 141.

[0207] In other embodiments, please refer to Figure 24 The second welding pool 140 includes two second sub-pools 141, which are spaced apart.

[0208] It is understood that in some embodiments, such as Figure 21 , Figure 22 and Figure 24 As shown, the number of first sub-melt pools 131 can be the same as the number of second sub-melt pools 141, and both can be one or more. In other embodiments, such as Figure 23 As shown, the number of first sub-melt pools 131 can be different from the number of second sub-melt pools 141.

[0209] In this embodiment, by setting one or more second sub-melt pools, the space of the main body on the plane parallel to the reference plane can be utilized as much as possible, the weld path length can be increased, thereby improving the connection strength between the adapter and the main body, and maximizing the overcurrent capacity between the two.

[0210] According to some embodiments of this application, please refer to Figure 21 and Figure 22 The first sub-melt pool 131 includes a linear melt pool extending in a straight direction.

[0211] Understandable. Figure 21In the first welding pool 130, the first welding pool 130 is located on the right side of the first direction Y, and the first welding pool 130 includes a first sub-melt pool 131. The second welding pool 140 is located on the left side of the first direction Y, and the second welding pool 140 includes a second sub-melt pool 141. Figure 22 In the first welding pool 130, the first welding pool 130 is located on the left side in the first direction and includes a first sub-melt pool 131. The second welding pool 140 is located on the right side in the first direction and includes a second sub-melt pool 141.

[0212] In this embodiment, the first sub-melt pool 131 can be a linear melt pool extending in a straight line, and the size of the linear melt pool can be set according to the size of the main body. The first sub-melt pool 131 can extend in a direction perpendicular to both the first direction Y and the axial direction, thereby providing greater clearance space for the first welding melt pool and the second welding melt pool in the first direction.

[0213] Figure 25 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application. Figure 26 For a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application, please refer to... Figure 25 and Figure 26 In some embodiments, the first sub-melt pool 131 includes a circular melt pool extending in an arc direction.

[0214] Understandable. Figure 25 In the first welding pool 130, the first welding pool 130 is located on the left side in the first direction and includes a first sub-melt pool 131. The second welding pool 140 is located on the right side in the first direction and includes a second sub-melt pool 141. Figure 26 In the first welding pool 130, the first welding pool 130 is located on the right side of the first direction and includes a first sub-melt pool 131. The second welding pool 140 is located on the left side of the first direction and includes a second sub-melt pool 141.

[0215] In this embodiment, the busbar component and the main body can be joined by laser welding, and laser welding can produce the following results: Figure 25 and Figure 26 The first sub-molten pool 131 shown is circular. Of course, the confluence component and the main body can also be formed by other welding methods.

[0216] Figure 27 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application. Figure 28 For a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application, please refer to... Figure 27 and Figure 28 In some embodiments, the first sub-melt pool 131 includes a point-like melt pool.

[0217] Understandable. Figure 27 In the first welding pool 130, the first welding pool 130 is located on the left side in the first direction and includes a first sub-melt pool 131. The second welding pool 140 is located on the right side in the first direction and includes a second sub-melt pool 141. Figure 28 In the first welding pool 130, the first welding pool 130 is located on the right side of the first direction and includes a first sub-melt pool 131. The second welding pool 140 is located on the left side of the first direction and includes a second sub-melt pool 141.

[0218] In this embodiment, the first sub-melt pool 131 can be a solid dot structure, and its outer contour shape can be a circle, square, ellipse, triangle, or other shapes.

[0219] Figure 29 This is a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application. Figure 30 For a top-view diagram showing the positional relationship between the first weld pool and the second weld pool in some embodiments of this application, please refer to... Figure 29 and Figure 30 In some embodiments, the first sub-melt pool 131 includes a closed melt pool formed by connecting the first arc segment 132 and the first straight segment 133 end to end.

[0220] Understandable. Figure 29 In the first welding pool 130, the first welding pool 130 is located on the left side in the first direction and includes a first sub-melt pool 131. The second welding pool 140 is located on the right side in the first direction and includes a second sub-melt pool 141. Figure 30 In the first welding pool 130, the first welding pool 130 is located on the right side of the first direction and includes a first sub-melt pool 131. The second welding pool 140 is located on the left side of the first direction and includes a second sub-melt pool 141.

[0221] In this embodiment, the first sub-molten pool 131 may include a first arc segment 132 and a first straight segment 133, which are connected end-to-end to form a closed semi-circular molten pool. It can be understood that the first straight segment 133 may be perpendicular to the first direction Y and the axial direction, and the first straight segment 133 may be located inside the first arc segment 132, that is, the first straight segment is closer to the axis of the main body.

[0222] This embodiment, by setting the first arc segment 132 and the first straight segment 133, can make reasonable use of the space of the main body, so that the weld path can be as long as possible, and can maximize the strength and overcurrent capacity of the welding interface between the main body and the busbar component.

[0223] All the above embodiments can achieve mutual avoidance between the first weld pool and the second weld pool in the first direction, effectively preventing the first weld pool and the second weld pool from connecting and causing the main body to be welded through.

[0224] According to some embodiments of this application, please refer to Figure 21 and Figure 22 The second sub-melt pool 141 includes a linear melt pool extending in a straight direction.

[0225] In this embodiment, the second sub-melt pool 141 can be a linear melt pool extending in a straight line, and the size of the linear melt pool can be set according to the size of the main body. The second sub-melt pool 141 can extend in a direction perpendicular to both the first direction and the axial direction, thereby providing greater clearance space for the first welding melt pool and the second welding melt pool in the first direction Y.

[0226] Please refer to Figure 25 and Figure 26 In some embodiments, the second sub-melt pool 141 includes a circular melt pool extending in an arc direction.

[0227] In this embodiment, the adapter and the main body can be joined by laser welding, and laser welding can produce the following results: Figure 25 and Figure 26 The annular second sub-molten pool 141 shown can, of course, be formed by other welding methods between the adapter and the main body.

[0228] Please refer to Figure 27 and Figure 28 In some embodiments, the second sub-melt pool 141 includes a point-like melt pool.

[0229] In this embodiment, the second sub-melt pool 141 can be a solid dot structure, and its outer contour shape can be a circle, square, ellipse, triangle, or other shapes.

[0230] Please refer to Figure 29 and Figure 30 In some embodiments, the second sub-melt pool 141 includes a closed melt pool formed by connecting the second arc segment 142 and the second straight segment 143 end to end.

[0231] In this embodiment, the second sub-molten pool 141 may include a second arc segment 142 and a second straight segment 143, which are connected end-to-end to form a closed semi-circular molten pool. It can be understood that the second straight segment 143 may be perpendicular to the first direction Y and the axial direction, and the second straight segment 143 may be located inside the second arc segment 142, that is, the second straight segment is closer to the axis of the main body.

[0232] This embodiment, by setting the second arc segment 142 and the second straight segment 143, can make reasonable use of the space of the main body, so that the weld path can be as long as possible, and can maximize the strength and overcurrent capacity of the welding interface between the main body and the adapter.

[0233] All the above embodiments can achieve mutual avoidance between the first weld pool and the second weld pool in the first direction, effectively preventing the first weld pool and the second weld pool from connecting and causing the main body to be welded through.

[0234] Furthermore, it is understandable. Figure 21 , Figure 22 , Figures 25 to 30 In each embodiment, only one first sub-molten pool 131 and one second sub-molten pool 141 are shown, and the first sub-molten pool 131 and the second sub-molten pool 141 have the same shape. In other embodiments, the number of first sub-molten pools 131 and second sub-molten pools 141 may both be multiple, or one may be multiple and the other may be one, and the number of both may be the same or different. In addition, the shape of the first sub-molten pool 131 and the shape of the second sub-molten pool may be the same or different.

[0235] According to some embodiments of this application, such as Figure 3 and Figure 10 As shown, the electrode terminal 18 also includes a connecting portion 113 and an insulating portion 114. The insulating portion 114 is sleeved outside the main body portion 111. One end of the connecting portion 113 is embedded in the insulating portion 114, and the other end of the connecting portion 113 is connected to the outer shell 30. At least a portion of the insulating portion 114 is located between the main body portion 111 and the connecting portion 113.

[0236] In this embodiment, the outer casing 30 may include an end cap assembly 12 and a housing 13. The housing 13 has an opening, and the end cap assembly 12 can be disposed over the opening so that the two together form a receiving cavity 31. In some embodiments, the end cap assembly 12 includes an end cap 17 and an insulating connector located inside the end cap 17. Main body 111

[0237] In this embodiment, the electrode terminal 18 includes a connecting part 113, an insulating part 114, and a main body part 111. The main body part 111 can be a columnar electrode post. The electrode post can be inserted into the end cap assembly 12 in the housing 30. It can be used to weld between the busbar component 120 and the adapter 112 to realize the electrical connection between the busbar component 120 and the adapter 112.

[0238] The insulating part 114 can be made of insulating materials such as plastic or rubber, and it can be a sleeve-shaped structure. The main body 111 can be fixedly installed in the insulating part 114, and the fixing method can be riveting, snap-fitting, screwing, etc.

[0239] The connecting part 113 can connect the electrode terminal 18 to the end cap assembly 12. Part of the connecting part 113 can be embedded in the insulating part 114. For example, the connecting part 113 can be a ring structure. Its end near the axial direction X can be embedded in the insulating part 114 by integral processing or other means. The end of the connecting part 113 away from the axial direction X can protrude out of the insulating part 114. This part can be connected to the end cap 17 in the end cap assembly 12. For example, the end cap 17 is provided with a mounting hole 16. The mounting hole 16 can penetrate the end cap 17. The connecting part 113 can be connected to the end cap 17 around the mounting hole 16 by welding or other means, so that the main body part 111 can be set corresponding to the mounting hole 16.

[0240] At least a portion of the insulating portion 114 is located between the main body portion 111 and the connecting portion 113, thereby isolating the main body portion 111 and the connecting portion 113. The insulating portion 114 can also be used to isolate the end cap 17 from the main body portion.

[0241] In some embodiments, such as Figure 12 The main body 111 includes a first segment 1111 and a second segment 1112. The end of the connecting portion 113 embedded in the insulating portion 114 also presses against at least part of the first segment 1111, thereby improving the connection strength between the first segment 1111 and the second segment 1112, as well as between the main body 111 and the end cap 17.

[0242] In this embodiment, the electrode terminals can be connected to the end cap through the connecting part, and the insulating part isolates the end cap and the main body, which can prevent short circuit between the two. At the same time, it can simplify the design of the main body. Unlike the related technology, which installs a riveting block on the outside of the electrode post and welds the busbar through the riveting block, it can further simplify the structure of the battery cell and improve the energy density of the battery cell.

[0243] This application provides a battery device 100, such as... Figure 2 As shown, the battery device 100 includes the battery cell 11 in the above embodiment.

[0244] It is understood that the battery device 100 provided in this application, by using any of the aforementioned battery cells 11, has all the beneficial effects of the aforementioned battery cells 11, which will not be repeated here.

[0245] This application provides an electrical device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to provide electrical energy.

[0246] Electrical devices include vehicles (such as cars, electric vehicles, ships, spacecraft, etc.), display devices (such as mobile phones, tablets, laptops, etc.), electric toys, power tools, etc.

[0247] It is understood that the electrical device provided in this application, by using any of the aforementioned battery cells 111, has all the beneficial effects of the aforementioned battery cells 11, which will not be elaborated here.

[0248] This application provides an energy storage device, which includes the battery device 100 in the above embodiments, and the battery device 100 is used to store electrical energy.

[0249] Energy storage devices can include, but are not limited to, centralized energy storage devices (such as containerized energy storage devices), distributed energy storage devices, mobile energy storage devices, wearable energy storage devices, and so on.

[0250] It is understood that the energy storage device provided in this application, by using any of the aforementioned battery cells 11, has all the beneficial effects of the aforementioned battery cells 11, which will not be elaborated here.

[0251] In one specific embodiment, the battery cell 11 includes a housing 30, an electrode assembly 14, and an electrode terminal 18. The housing 30 has a receiving cavity 31. The electrode assembly 14 is received in the receiving cavity 31 and includes an electrode body 15 and a tab 19 disposed at one end of the electrode body 15. The electrode terminal 18 is disposed on the housing 30 and includes a main body portion 111. A first end of the main body portion 111 along the axial direction X is used for electrical connection with a current collector 120, and a second end of the main body portion 111 along the axial direction X is electrically connected to the tab 19. The first end of the main body portion 111 has a first weld pool 130 for electrical connection with the current collector 120, and the second end of the main body portion 111 has a second weld pool 140 for electrical connection with the tab 19. With a plane perpendicular to the axial direction X as the reference plane A, the first orthographic projection of the first weld pool 130 on the reference plane A and the second orthographic projection of the second weld pool 140 on the reference plane A are offset from each other, and the third orthographic projection of the first weld pool 130 on the axial direction X and the fourth orthographic projection of the second weld pool 140 on the axial direction X at least partially coincide.

[0252] It is understood that in this embodiment, the first end of the main body 111 is welded to the busbar component 120, and the second end of the main body 111 is welded to the adapter 112, so as to electrically connect to the electrode 19 through the adapter 112. The main body can be enlarged, for example, the diameter of the main body can be greater than 8mm or greater than 9mm. The enlarged size is to provide space and conditions for the first weld pool and the second weld pool to avoid each other in the direction parallel to the reference plane, so that the first orthographic projection and the second orthographic projection are staggered.

[0253] in, Figure 12 As shown, electrode terminal 18 includes a first electrode terminal. The main body 111 of the first electrode terminal includes a first segment 1111 and a second segment 1112. The second segment 1112 is connected to one end of the first segment 1111 along the axial direction X. The first segment 1111 is provided with a first weld pool 130, and the first weld pool 130 extends along the axial direction X to a portion located in the second segment 1112. The second segment 1112 is provided with a second weld pool 140, and the second weld pool 140 extends along the axial direction to a portion located in the first segment 1111. The constituent material of the first segment 1111 (aluminum) is different from the constituent material of the second segment 1112 (copper).

[0254] Because the first weld pool 130 and the second weld pool 140 are designed with a cross-Cu-Al composite interface, the height of the main body can be further reduced, allowing the final height of the main body to be slightly greater than the height of the first weld pool (or slightly greater than the height of the second weld pool). This prevents the main body from being welded through, which could lead to failure of the airtightness function and subsequent leakage of the battery cells. Simultaneously, the first and second weld pools are designed to avoid each other in a plane perpendicular to the axis direction. Without this avoidance, the main body could easily be welded through, leading to failure of the airtightness function. Therefore, in this embodiment, the first and second orthographic projections are staggered to prevent interference between the first and second weld pools.

[0255] like Figure 11 As shown, the first weld pool 130 extends circumferentially along the main body 111 in a closed ring shape, and the second orthographic projection is located within the space enclosed by the first orthographic projection. That is, the second weld pool 140 is inside, and the first weld pool 130 is on the outer ring. The two can avoid each other in a direction parallel to the reference plane. At the same time, the first weld pool 130 and the second weld pool 140 share a common axial direction space. In this way, the thickness of the main body can be further reduced, and the situation of direct laser welding through the main body and leakage of battery cells during welding of busbar components and adapters can be improved.

[0256] In some embodiments, the main body may be designed to be thinner, such as... Figure 12 The dimensional relationships of the main body are as follows: 2.5mm < H1 + H2 < 3.8mm, where 0.8mm < H2 < 1.3mm and 1.6mm < H1 < 2.5mm.

[0257] In this embodiment, to address the issue that excessive height of the main body affects the energy density improvement of individual battery cells, a design is provided where the weld pool spans the interface of the composite main body, providing conditions for thinning the main body. Simultaneously, a design is implemented to avoid weld penetration between the busbar and the adapter, and the weld pools of the busbar and the adapter share the same height space as the individual battery cells, further thinning the main body and ultimately achieving the goal of increasing the energy density of the individual battery cells.

[0258] It is understandable that the main body 111 plays an important role in connecting the internal and external circuits of the battery cell 11. Therefore, the main body 111 is required to have the following functions: (1) overcurrent capability, (2) structural strength, and (3) airtightness. In addition, the welding interface between the main body and the busbar component, and the welding interface between the main body and the adapter component also need to meet the functions of (1) overcurrent capability, (2) structural strength, and (3) airtightness.

[0259] In this embodiment, to ensure that the first orthographic projection and the second orthographic projection are staggered, the main body can be enlarged in the direction parallel to the reference plane. This gives the main body sufficient structural strength and provides enough space to ensure that the first orthographic projection and the second orthographic projection are staggered. This means that the connection strength and overcurrent capacity of the weld interface can be satisfied without significantly reducing the size of the weld pool. In addition, by setting the dimensional relationship of each part of the main body, the airtightness problem caused by the weld being too small can be prevented, thus satisfying the airtightness function.

[0260] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, include: The outer shell has a receiving cavity; An electrode assembly is housed in the receiving cavity, and the electrode assembly includes an electrode body and a tab disposed at one end of the electrode body; An electrode terminal is disposed in the housing, and the electrode terminal includes a main body portion. A first end of the main body portion along the axial direction of the main body portion is used for electrical connection with a busbar component, and a second end of the main body portion along the axial direction is electrically connected to the tab. The first end of the main body portion has a first weld pool for electrical connection with the busbar component, and the second end of the main body portion has a second weld pool for electrical connection with the tab. Using a plane perpendicular to the axial direction as a reference plane, the first orthographic projection of the first weld pool on the reference plane and the second orthographic projection of the second weld pool on the reference plane are offset from each other, and the third orthographic projection of the first weld pool on the axial direction and the fourth orthographic projection of the second weld pool on the axial direction at least partially coincide.

2. The battery cell according to claim 1, characterized in that, The electrode terminal includes a first electrode terminal, the main body of the first electrode terminal includes a first segment and a second segment, the second segment is connected to one end of the first segment along the axial direction, the first segment is provided with a first weld pool, the second segment is provided with a second weld pool, and the constituent material of the first segment is different from the constituent material of the second segment.

3. The battery cell according to claim 2, characterized in that, The first weld pool also extends along the axial direction to a portion located in the second segment.

4. The battery cell according to claim 2, characterized in that, The second weld pool also extends along the axial direction to a portion located within the first segment.

5. The battery cell according to claim 2, characterized in that, The first weld pool also extends along the axial direction to a portion located in the second segment, and the second weld pool also extends along the axial direction to a portion located in the first segment.

6. The battery cell according to any one of claims 2-5, characterized in that, The first height H1 of the first segment along the axis direction satisfies: 1.6mm <H1<2.5mm。 7. The battery cell according to any one of claims 2-6, characterized in that, The second height H2 of the second segment along the axial direction satisfies: 0.8mm <H2<1.3mm。 8. The battery cell according to any one of claims 2-7, characterized in that, The first height H1 of the first segment along the axis and the second height H2 of the second segment along the axis satisfy the following condition: 2.5mm. <H1+H2<3.8mm。 9. The battery cell according to any one of claims 1-8, characterized in that, The first weld pool extends circumferentially along the main body to form a closed ring, and the second orthographic projection is located within the area enclosed by the first orthographic projection.

10. The battery cell according to claim 9, characterized in that, The first end of the main body is also provided with a first positioning part for welding positioning, and the first positioning part is located in the area enclosed by the first weld pool.

11. The battery cell according to any one of claims 1-8, characterized in that, The second weld pool extends circumferentially along the main body to form a closed ring, and the first orthographic projection is located within the area enclosed by the second orthographic projection.

12. The battery cell according to claim 10, characterized in that, The first end of the main body is also provided with a plurality of second positioning parts for welding positioning, and the plurality of second positioning parts are arranged around the outside of the first welding pool.

13. The battery cell according to any one of claims 1-8, characterized in that, The first weld pool and the second weld pool are arranged at intervals in a first direction, wherein the first direction is a direction perpendicular to the axis direction.

14. The battery cell according to claim 13, characterized in that, The first weld pool includes a first sub-welded pool; or, The first weld pool includes a plurality of first sub-pools that are separated from each other.

15. The battery cell according to claim 14, characterized in that, The first sub-molten pool includes a linear molten pool extending in a straight direction; or, The first sub-melt pool includes a circular melt pool extending along an arc direction; or, The first sub-melt pool includes a point-shaped melt pool; or, The first sub-melt pool includes a closed melt pool formed by connecting the first arc segment and the first straight segment end to end.

16. The battery cell according to any one of claims 13-15, characterized in that, The second weld pool includes a second sub-weld pool; or, The second weld pool includes a plurality of second sub-pools that are separated from each other.

17. The battery cell according to claim 16, characterized in that, The second sub-molten pool includes a linear molten pool extending in a straight direction; or, The second sub-melt pool includes a circular melt pool extending along an arc direction; or, The second sub-melt pool includes a point-like melt pool; or, The second sub-melt pool includes a closed melt pool formed by connecting the second arc segment and the second straight segment end to end.

18. The battery cell according to any one of claims 1-17, characterized in that, The electrode terminal further includes a connecting portion and an insulating portion. The insulating portion is sleeved outside the main body portion. One end of the connecting portion is embedded in the insulating portion, and the other end of the connecting portion is connected to the outer shell. At least a portion of the insulating portion is located between the main body portion and the connecting portion.

19. A battery device characterized by comprising: Includes the battery cell as described in any one of claims 1-18.

20. An electrical device, comprising: The electrical device includes the battery device as described in claim 19, the battery device being used to provide electrical energy.

21. An energy storage device, comprising: The energy storage device includes the battery device as described in claim 19, the battery device being used to store electrical energy.

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