Battery cell, battery device, and electric device

Abstract

The application discloses a battery cell, a battery device and a power utilization equipment. The battery cell comprises a shell, an electrode assembly, a first adapter, a first electrode terminal, a sealing member and a first conductive member. The first adapter is connected to a first tab of the electrode assembly. The first electrode terminal is fixedly arranged on a wall portion of the shell and is welded with the first adapter to form a first welding portion. At least part of the sealing member is arranged between the first electrode terminal and the wall portion. The first conductive member is arranged on a side of the first welding portion away from a main body portion and is used for covering the first welding portion. The first conductive member comprises a first conductive portion and a second conductive portion which are connected to each other and have different base metals, the first conductive portion is welded to the first electrode terminal, and the second conductive portion is at least partially arranged on a side of the first conductive portion away from the main body portion of the electrode assembly and is used for being connected to a busbar member. The application can reduce the influence of the first conductive member on the sealing effect between the first electrode terminal and the wall portion, and improve reliability and sealing performance.

Description

Technical Field

[0001] This application belongs to the field of battery technology, and in particular relates to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Batteries are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the development of battery technology, improving the reliability and sealing performance of individual battery cells is a key research direction. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical appliance, which are beneficial for improving the reliability and sealing performance of the battery cell.

[0005] According to a first aspect of this application, a battery cell is provided, comprising a housing, an electrode assembly, a first electrode terminal, a seal, and a first conductive element. The housing includes a wall portion with an electrode lead-out hole. The electrode assembly is housed within the housing and includes a main body portion and a first tab extending from the main body portion. A first adapter is connected to the first tab. The first electrode terminal is fixedly disposed on the wall portion and partially housed in the electrode lead-out hole. The first electrode terminal is welded to the first adapter to form a first weld portion, which is exposed on the side of the first electrode terminal away from the main body portion. The seal is disposed along the thickness direction of the wall portion, with at least a portion of the seal located between the first electrode terminal and the wall portion. The first conductive element is disposed on the side of the first weld portion away from the main body portion and serves to cover the first weld portion. The first conductive element includes a first conductive portion and a second conductive portion connected to each other. The base metals of the first conductive portion and the second conductive portion are different. The base metals of the first conductive portion and the first electrode terminal are the same. The first conductive portion is welded to the first electrode terminal. Along the thickness direction of the wall portion, at least a portion of the second conductive portion is located on the side of the first conductive portion away from the main body portion and serves to connect to a busbar component.

[0006] The first adapter and the first electrode terminal are welded from the outside, which helps reduce the possibility of welding particles falling into the casing during the welding process, reducing the risk of internal short circuits and improving the reliability of the battery cell. The first conductive element can cover the first weld portion exposed from the outside of the first electrode terminal, reducing the risk of corrosion of the first weld portion. The first electrode terminal is fixed to the wall, and the seal between the first electrode terminal and the wall does not depend on the first conductive element. This helps reduce the influence of the first conductive element on the sealing interface between the first electrode terminal and the wall, reducing the risk of seal failure between the first electrode terminal and the wall due to the breakage of the connection interface between the first conductive part and the second conductive part, and improving the reliability of the battery cell.

[0007] In some embodiments, the first electrode terminal includes a terminal body, a first limiting portion, and a second limiting portion. The first limiting portion is at least partially disposed on the side of the wall portion away from the main body portion, and the second limiting portion is at least partially disposed on the side of the wall portion closer to the main body portion. At least a portion of the terminal body is accommodated in an electrode lead-out hole and connects the first limiting portion and the second limiting portion. Along the thickness direction, at least a portion of a sealing member is disposed between the wall portion and the second limiting portion. The terminal body is welded to a first adapter to form a first weld portion, and a first conductive portion is welded to the terminal body. At least portions of the first limiting portion and the second limiting portion are respectively disposed on both sides of the wall portion along the thickness direction, which can limit the first electrode terminal in the thickness direction and facilitates the fixation of the first electrode terminal relative to the housing.

[0008] In some embodiments, a first recess is provided on the side of the terminal body away from the main body portion. A first conductive element covers the first recess, and a first bottom wall of the first recess is welded to the first adapter to form a first weld portion, which is exposed in the first recess. The first bottom wall of the first recess is closer to the side of the wall portion facing the main body portion, which helps to reduce the welding difficulty of the first electrode terminal and the first adapter, and improve the welding effect; it also helps to reduce the thickness of the portion of the terminal body used for welding with the first adapter, reduce welding power, and reduce welding heat generation.

[0009] In some embodiments, the first conductive portion and the first weld portion are spaced apart along the thickness direction. The first weld portion does not contact the first conductive portion, which helps to reduce the risk of interference between the first conductive portion and the first weld portion and improves the connection stability between the first conductive portion and the first electrode terminal.

[0010] In some embodiments, the first welding portion and the sidewall of the first recess are spaced apart. This helps to reduce the welding difficulty of the first electrode terminal and the first adapter, and improves assembly efficiency.

[0011] In some embodiments, the terminal body has a first through hole that penetrates the first bottom wall of the first recess along its thickness direction; a portion of the first adapter is accommodated in the first through hole and welded to the terminal body to form a first welded portion. This facilitates determining the welding position during welding operations and reduces welding difficulty. The first through hole can limit the position of the first adapter, which helps reduce the risk of relative displacement between the terminal body and the first adapter during welding operations and improves welding stability.

[0012] In some embodiments, a second recess is provided on the side of the terminal body near the main body portion. The terminal body includes a partition wall that separates the first recess and the second recess along the thickness direction. At least a portion of the first adapter is accommodated in the second recess, and the first adapter is welded to the partition wall to form a first weld portion. This facilitates reducing the thickness of the partition wall used for welding with the first adapter, reducing the welding power of the first electrode terminal and the first adapter, reducing welding heat generation, and improving welding stability.

[0013] In some embodiments, in the same plane perpendicular to the thickness direction, the orthographic projection range of the first recess exceeds the orthographic projection range of the second recess. A larger orthographic projection range of the first recess is beneficial for increasing the distance between the first weld portion and the sidewall of the first recess, reducing welding difficulty, decreasing welding heat transferred to the sidewall of the first recess, and reducing the risk of deformation of the terminal body.

[0014] In some embodiments, the first conductive portion is at least partially accommodated in the first recess and welded to the sidewall of the first recess. The first conductive portion and the first electrode terminal can share a portion of the space in the thickness direction, which helps to save the space occupied by the battery cell in the thickness direction and improve the energy density of the battery cell.

[0015] In some embodiments, the first recess includes a first sub-recess and a second sub-recess, which are arranged along the direction from the main body to the wall. In the same plane perpendicular to the thickness direction, the orthographic projection range of the second sub-recess exceeds the orthographic projection range of the first sub-recess. The first conductive portion is at least partially accommodated in the second sub-recess and welded to the sidewall of the second sub-recess. A portion of the surface of the first recess can support the first conductive portion, which helps to improve the support stability of the first conductive portion and the connection stability between the first conductive portion and the terminal body.

[0016] In some embodiments, the first recess includes a third sub-recess, and the first, second, and third sub-recesses are arranged sequentially along the direction from the main body to the wall. In the same plane perpendicular to the thickness direction, the orthographic projection range of the third sub-recess exceeds the orthographic projection range of the second sub-recess. The first conductive portion is welded to the terminal body to form a second weld portion. The second weld portion connects to the side of the second sub-recess and the first outer peripheral surface of the first conductive portion, and a portion of the second weld portion is accommodated in the third sub-recess. During welding, the third sub-recess can provide clearance space for the molten portion of the first conductive portion and the terminal body, allowing at least a portion of the molten portion to flow away from the first outer peripheral surface of the first conductive portion. This helps to reduce the size of the second weld portion along the thickness direction after the molten portion solidifies, reduces the possibility of the second weld portion extending beyond the third sub-recess, and lowers the risk of wear on the second weld portion leading to connection failure between the first electrode terminal and the first conductive element. The combination of the first and second weld portions provides a double sealing effect, which helps to improve the sealing performance of the battery cell.

[0017] In some embodiments, the first conductive portion includes a first conductive sub-portion and a second conductive sub-portion, which are stacked along the direction from the main body portion to the wall portion. The second conductive sub-portion surrounds the first conductive sub-portion and protrudes from the second outer peripheral surface of the second conductive sub-portion. The second conductive sub-portion is welded to the sidewall of the first recess. A third recess is provided on the side of the second conductive sub-portion facing the second conductive portion. The third recess can provide stress relief space, which helps to alleviate and release the stress experienced by the first conductive portion and the terminal body during welding, and reduces the risk of breakage of the first conductive portion and the terminal body.

[0018] In some embodiments, the thickness of the second limiting portion is greater than the thickness of the first limiting portion. On the one hand, this helps to improve the structural strength of the first electrode terminal and enhance the stability of the first electrode terminal relative to the wall; on the other hand, the second limiting portion can share a portion of the space in the thickness direction with the first electrode tab and / or the first adapter, reducing the additional space occupied in the thickness direction.

[0019] In some embodiments, the first adapter includes an adapter body, a first protrusion, and a second protrusion. The adapter body connects the first and second protrusions along a first direction perpendicular to the thickness direction. At least a portion of the adapter body is located on the side of the second limiting portion away from the wall portion. Both the first and second protrusions protrude from the surface of the adapter body facing the second limiting portion. The first protrusion is welded to the terminal body to form a first weld portion, and the second protrusion is located on the side of the second limiting portion along the first direction. At least a portion of the first tab is located on the side of the second protrusion closest to the body portion and is connected to the second protrusion. The side of the second protrusion facing the body portion can form a receiving space for accommodating at least a portion of the first tab. The second protrusion and the first tab can share a portion of the space in the thickness direction with the second limiting portion, which is beneficial for improving space utilization and increasing the energy density of the battery cell.

[0020] In some embodiments, along the thickness direction, a portion of the first tab is located between the second limiting portion and the first adapter, and is connected to the first adapter and the second limiting portion. Overcurrent paths are formed between the first tab and the first adapter, and between the first tab and the second limiting portion, allowing some current to be directly transmitted between the first tab and the first electrode terminal, which helps improve the overcurrent capacity of the battery cell.

[0021] In some embodiments, the first electrode terminal includes a first surface facing away from the main body in the thickness direction, and at least a portion of the second conductive portion extends beyond the first surface in the direction from the main body to the wall. This reduces the risk of interference between the busbar and the first electrode terminal when connecting the busbar and the second conductive portion, thereby improving the connection reliability of the busbar and the second conductive portion.

[0022] In some embodiments, the first conductive portion and the second conductive portion are connected by at least one of cold rolling, hot rolling, explosive bonding, and explosive rolling. This improves the connection strength and stability between the first and second conductive portions and reduces the risk of separation of the connection surfaces.

[0023] In some embodiments, the electrode assembly includes a second tab extending from the main body, the second tab having the opposite polarity to the first tab; the battery cell also includes a second electrode terminal and a second adapter, the second electrode terminal being electrically connected to the second tab and the second adapter; the base metal of the second electrode terminal is the same as the base metal of the second conductive portion. The second conductive portion of one battery cell and the second electrode terminal of another battery cell can be soldered to the same busbar, which facilitates series connection between two battery cells and reduces connection difficulty.

[0024] In some embodiments, a fourth recess is provided on the side of the second electrode terminal away from the main body. The second electrode terminal has a second through hole that penetrates the second bottom wall of the fourth recess along the thickness direction. At least a portion of the second adapter is accommodated in the second through hole and welded to the second electrode terminal to form a third weld portion, which is exposed in the fourth recess. The battery cell includes a second conductive element, which is welded to the second electrode terminal and used for connection with a busbar. Along the thickness direction, the second conductive element covers the fourth recess. The second adapter and the second electrode terminal are welded from the outside, which helps to reduce the possibility of welding particles generated during the welding process falling into the casing, reducing the risk of internal short circuits and improving the reliability of the battery cell. The second conductive element can cover the third weld portion exposed from the outside of the second electrode terminal, reducing the risk of corrosion of the third weld portion.

[0025] In some embodiments, the base metal of the first conductive portion and the base metal of the first electrode terminal are both copper; the base metal of the second conductive portion is aluminum.

[0026] In some embodiments, the housing includes a shell and an end cap, the shell having an opening, and the end cap being connected to the shell and covering the opening; the wall portion serves as the end cap. This simplifies assembly operations and reduces assembly difficulty.

[0027] According to a second aspect of this application, this application provides a battery device comprising a battery cell and a current-collecting component provided according to any embodiment of the first aspect, wherein the base metal of the current-collecting component is the same as the base metal of the second conductive portion, and the current-collecting component is welded to the second conductive portion.

[0028] According to a third aspect of this application, this application provides an electrical device that includes a battery device provided according to any embodiment of the second aspect of this application, the battery device being used to provide electrical energy. Attached Figure Description

[0029] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 These are schematic diagrams of the vehicle structure provided in some embodiments of this application.

[0031] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application.

[0032] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application.

[0033] Figure 4 yes Figure 3 The diagram shows a top view of a single battery cell.

[0034] Figure 5 It is along Figure 4 The cross-sectional view taken from direction AA in the middle.

[0035] Figure 6 yes Figure 5 A magnified structural diagram of region B in the middle.

[0036] Figure 7 This is a partial structural cross-sectional view of a battery cell provided in other embodiments of this application.

[0037] Figure 8 yes Figure 6 A schematic diagram of its decomposed structure.

[0038] Figure 9 yes Figure 6 A magnified structural diagram of region C in the middle.

[0039] Figure 10 This is a cross-sectional view of the first electrode terminal of a battery cell provided in some embodiments of this application.

[0040] Figure 11 This is a cross-sectional view of a battery cell provided in some embodiments of this application.

[0041] Figure 12 It is along Figure 4 A sectional view of the part of the structure cut off in the direction DD.

[0042] Figure 13 This is a cross-sectional view of a battery device provided in some embodiments of this application.

[0043] In the attached image:

[0044] Vehicle 1, battery unit 2, controller 3, motor 4, busbar 7;

[0045] Box 5, first box section 5a, second box section 5b, and accommodating space 5c;

[0046] Battery cell 6, electrode assembly 10, main body 11, first tab 12, second tab 13, outer casing 20, housing 21, opening 211, end cap 22, wall 23, electrode lead-out hole 231, second surface 23a, first electrode terminal 30, first surface 30a, terminal body 31, first recess 311, first sub-recess 3111, first inner peripheral surface 3111a, second sub-recess 3112, second inner peripheral surface 3112a, third sub-recess 3113, third inner peripheral surface 3113a, first stepped surface 311a, second stepped surface 311b, first bottom wall 312, first through hole 313, second recess 3 14, partition wall 315, first limiting part 32, second limiting part 33, first adapter 40, adapter body 41, first protrusion 42, second protrusion 43, first conductive element 60, first conductive part 61, first conductive sub-part 611, second conductive sub-part 612, third recess 613, first outer peripheral surface 61a, second conductive part 62, second outer peripheral surface 62a, connecting surface 63, second electrode terminal 70, fourth recess 71, second through hole 72, second bottom wall 73, second adapter 80, second conductive element 90, first welding part W1, second welding part W2, third welding part W3, thickness direction X, first direction Y. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application 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 description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0049] In this application, the reference to "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 in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0051] 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: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0052] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0053] In this application, "multiple" means two or more (including two).

[0054] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0055] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0056] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0057] A typical battery cell includes an electrode assembly, a housing, and electrode terminals. The electrode assembly is housed within the housing, and the electrode terminals are located within the housing. The housing encapsulates the electrode assembly and electrolyte components. The electrode assembly includes tabs, which are electrically connected to the electrode terminals via adapters or directly to the electrode terminals. The electrode terminals are used to electrically connect the electrode assembly to external circuitry within the battery cell to enable charging or discharging of the battery cell.

[0058] The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0059] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0060] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0061] In some implementations, the separator is positioned between the positive and negative electrodes.

[0062] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0063] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0064] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0065] In some embodiments, the electrode assembly has a stacked structure.

[0066] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0067] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0068] A battery device typically includes a housing for encapsulating one or more individual battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0069] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into an independent module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties. The battery cell assembly can be housed within a housing by fixing the battery module within the housing. As an example, the housing can include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, creating a closed space inside the housing to house the battery cell assembly.

[0070] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0071] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0072] Electrode terminals typically connect the electrode assembly to the external circuitry of the battery cell via a busbar. When the tabs of the busbar and the electrode assembly are made of different materials, composite materials are required for the electrode terminals due to limitations in the connection process. In related technologies, the electrode terminal comprises a first part and a second part made of different materials, which can be joined together by friction welding or other connection methods. The first part is at least partially located inside the housing and connected to the tab via an adapter; the second part is at least partially located outside the housing and is used to connect to the busbar. Through the connection between the first and second parts, the first part can form a seal with the housing of the battery cell. However, the composite interface between the first and second parts is at risk of breakage due to the tensile force of the busbar and the adapter. If the first and second parts break, the first part lacks support, and the seal between the first part and the housing is prone to failure, posing risks such as leakage, short circuit, and fire, thus affecting the reliability of the battery cell.

[0073] In view of this, this application provides a technical solution that fixes a first electrode terminal to the wall of the housing, welds the first electrode terminal to a first adapter to form a first welded portion, and sets the first conductive element used to cover the first welded portion as a composite structure including a first conductive portion and a second conductive portion with different base metals. The first conductive portion and the second conductive portion can be welded to the first electrode terminal and the busbar component, respectively, to achieve electrical connection between the battery cell and the external circuit. The seal between the first electrode terminal and the wall does not depend on the first conductive element, which helps to reduce the influence of the first conductive element on the sealing interface between the first electrode terminal and the wall, reduces the risk of seal failure between the first electrode terminal and the wall caused by the fracture of the composite interface between the first conductive portion and the second conductive portion, and improves the reliability of the battery cell.

[0074] The technical solutions provided in this application are applicable to battery cells, battery devices, and electrical equipment using battery devices.

[0075] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are 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.

[0076] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0077] Figure 1 This is a structural schematic diagram of a vehicle provided in some embodiments of this application. (Refer to...) Figure 1 Vehicle 1 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 2 is installed inside vehicle 1, and the battery device 2 can be located at the bottom, front, or rear of vehicle 1. The battery device 2 can be used to power vehicle 1; for example, the battery device 2 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0078] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0079] Figure 2 This is an exploded structural diagram of a battery device provided in some embodiments of this application. (Refer to...) Figure 2The battery device 2 includes a housing 5 and a battery cell 6, with the battery cell 6 housed within the housing 5. The housing 5 provides a space for the battery cell 6 and can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, together defining a space 5c for accommodating the battery cell 6. The second housing portion 5b may be a hollow structure with one open end, while the first housing portion 5a may be a plate-like structure, covering the open side of the second housing portion 5b so that the first housing portion 5a and the second housing portion 5b together define the space 5c. Alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one open side, with the open side of the first housing portion 5a overlapping the open side of the second housing portion 5b. Of course, the box 5 formed by the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0080] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0081] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0082] In the battery device 2, there can be multiple battery cells 6, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel configurations. Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 6 is housed within the housing 5. Alternatively, the battery device 2 can also consist of multiple battery cells 6 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 5. The battery device 2 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 6.

[0083] For example, the battery cell 6 may be the smallest unit that makes up the battery device 2.

[0084] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. (Refer to...) Figure 3 The battery cell 6 includes an electrode assembly 10 and a housing 20, with the electrode assembly 10 disposed inside the housing 20.

[0085] The outer casing 20 is used to encapsulate the electrode assembly 10 and electrolyte components. The outer casing 20 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0086] In some embodiments, the housing 20 is a hollow structure, with an internal space for accommodating the electrode assembly 10 and the electrolyte. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 has a cuboid structure, a cuboid housing can be selected.

[0087] The outer casing 20 can be made of various materials, such as metal or plastic. Optionally, the outer casing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the outer casing 20 can be a steel casing, aluminum casing, plastic casing (such as polypropylene), composite metal casing (such as copper-aluminum composite casing), or aluminum-plastic film, etc.

[0088] As an example, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening 211 and the end cap 22 for closing the opening 211.

[0089] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte, and other components.

[0090] The housing 21 and the end cap 22 can be separate components. For example, an opening 211 can be provided on the housing 21, and the end cap 22 can be used to close the opening 211 to form an internal cavity for the battery cell 6.

[0091] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21.

[0092] The end cap 22 can be connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0093] The housing 21 may have an opening 211 at one end or at both ends. For example, the housing 21 may have an opening 211 on one side, with an end cap 22 covering the opening 211 of the housing 21. Alternatively, the housing 21 may have openings 211 on both sides, with two end caps 22 covering the two openings 211 of the housing 21 respectively.

[0094] Figure 4 yes Figure 3 The diagram shows a top view of a single battery cell. Figure 5 It is along Figure 4 The sectional view taken from direction AA in the middle. Figure 6 yes Figure 5A magnified structural diagram of region B in the middle. Figure 7 This is a partial structural cross-sectional view of a battery cell provided in other embodiments of this application. Figure 8 yes Figure 6 A schematic diagram of the decomposed structure. Figure 9 yes Figure 6 A magnified structural diagram of region C in the middle. Figure 10 This is a cross-sectional view of the first electrode terminal of a battery cell provided in some embodiments of this application. Figure 11 This is a cross-sectional view of a battery cell provided in some embodiments of this application. Figure 12 It is along Figure 4 A sectional view of the part of the structure cut off in the direction DD.

[0095] Reference Figures 3 to 12 In some embodiments, the battery cell 6 includes an electrode assembly 10, a housing 20, a first electrode terminal 30, a first adapter 40, a seal 50, and a first conductive element 60. The housing 20 includes a wall portion 23 with an electrode lead-out hole 231. The electrode assembly 10 is housed within the housing 20 and includes a main body portion 11 and a first tab 12 extending from the main body portion 11. The first adapter 40 is connected to the first tab 12. The first electrode terminal 30 is fixedly disposed on the wall portion 23 and partially housed in the electrode lead-out hole 231. The first electrode terminal 30 is welded to the first adapter 40 to form a first weld portion W1, which is exposed on the side of the first electrode terminal 30 away from the main body portion 11. At least a portion of the seal 50 is disposed between the first electrode terminal 30 and the wall portion 23 along the thickness direction X of the wall portion 23. The first conductive element 60 is disposed on the side of the first weld portion W1 away from the main body portion 11 and serves to cover the first weld portion W1. The first conductive element 60 includes a first conductive portion 61 and a second conductive portion 62 connected to each other. The base metals of the first conductive portion 61 and the second conductive portion 62 are different. The base metal of the first conductive portion 61 is the same as that of the first electrode terminal 30. The first conductive portion 61 is soldered to the first electrode terminal 30. Along the thickness direction X of the wall portion 23, at least a portion of the second conductive portion 62 is located on the side of the first conductive portion 61 away from the main body portion 11 and is used for connection with the busbar component.

[0096] The wall portion 23 can be an end cap 22 or one of the shell walls of the housing 21. Optionally, in Figure 3 and Figure 4 In the embodiment shown, the wall portion 23 is an end cap 22.

[0097] The main body 11 is the core component of the electrode assembly 10, enabling its charging and discharging functions. The first tab 12 can be led out from one end of the main body 11 near the wall 23, or from other ends of the main body 11. Optionally, in Figure 3In the embodiment shown, the first tab 12 is led out from the end of the main body 11 near the wall 23, which helps to simplify the structure of the first adapter 40.

[0098] The first adapter 40 can be connected to the first tab 12 by welding, bonding or other suitable means.

[0099] The first electrode terminal 30 is disposed on the wall portion 23 and fixed relative to the wall portion 23. Optionally, the first electrode terminal 30 can be fixed to the wall portion 23 by riveting or by a fastener.

[0100] The seal 50 is used to seal the first electrode terminal 30 and the wall portion 23. A portion of the first electrode terminal 30 is located on one side of the wall portion 23 along the thickness direction X, and at least a portion of the seal 50 can be clamped between the first electrode terminal 30 and the wall portion 23.

[0101] At least a portion of the seal 50 may be disposed around the electrode lead-out hole 231 to achieve a seal between the first electrode terminal 30 and the wall portion 23 over the entire circumference of the electrode lead-out hole 231.

[0102] The first electrode terminal 30 and the first adapter 40 can be welded by through welding or butt welding. Optionally, the first electrode terminal 30 and the first adapter 40 can be heated by irradiation with a laser, so that a portion of the first electrode terminal 30 and a portion of the first adapter 40 melt and fuse together, and the fused portion solidifies to form the first welded part W1.

[0103] The first welding part W1 can be one or more.

[0104] The first welded part W1 can be ring-shaped, arc-shaped, strip-shaped, or other suitable shapes.

[0105] The first weld portion W1 being exposed on the side of the first electrode terminal 30 away from the main body 11 means that the first weld portion W1 can be seen and exposed from the side of the first electrode terminal 30 away from the main body 11. The side of the first electrode terminal 30 away from the main body 11 is the outer side of the first electrode terminal 30 facing away from the interior of the housing 20. The first weld portion W1 is seen and exposed from the outer side of the first electrode terminal 30.

[0106] During the welding operation, the first electrode terminal 30 and the first adapter 40 can be heated from the outside of the first electrode terminal 30, so that the first welding part W1 is exposed on the outside of the first electrode terminal 30. This helps to reduce the possibility of welding particles generated during the welding process falling into the side of the first adapter 40 facing the main body 11, reduce the risk of internal short circuit of the battery cell 6, and improve the reliability of the battery cell 6.

[0107] In the same plane perpendicular to the thickness direction X, the orthographic projection of the first welded portion W1 can lie within the orthographic projection of the first conductive element 60. The first conductive element 60 can cover the first welded portion W1 from the outside, reducing the risk of corrosion of the first welded portion W1.

[0108] The first conductive part 61 and the second conductive part 62 may be connected by welding, rolling or other suitable means.

[0109] In the embodiments of this application, "base metal" refers to the main metal component. The main metal component of the first conductive part 61 is different from that of the second conductive part 62, and the main metal component of the first conductive part 61 is the same as that of the first electrode terminal 30, so as to facilitate welding of the first conductive part 61 and the first electrode terminal 30.

[0110] Optionally, the first electrode tab 12 is a negative electrode tab. The first conductive part 61 and the first electrode terminal 30 can be made of aluminum or aluminum alloy, and the base metal of the first conductive part 61 and the first electrode terminal 30 is aluminum. The second conductive part 62 can be made of copper or copper alloy, and the base metal of the second conductive part 62 is copper.

[0111] Optionally, the base metal of the first adapter 40 is the same as the base metal of the first electrode terminal 30 to facilitate welding between the two.

[0112] The second conductive part 62 is used to connect to the busbar component. The second conductive part 62 can be connected to the busbar component by welding, bonding or other suitable means.

[0113] Optionally, the base metal of the second conductive part 62 may be the same as the base metal of the bus component, so that the two can be connected by welding, which is beneficial to improving the connection strength and connection stability.

[0114] The second conductive portion 62 may be located entirely on the side of the first conductive portion 61 away from the main body portion 11, or only a portion of the second conductive portion 62 may be located on the side of the first conductive portion 61 away from the main body portion 11, and the other portion of the second conductive portion 62 may, for example, cover the outer periphery of a portion of the first conductive portion 61.

[0115] During assembly, the first tab 12 can be connected to the first adapter 40 and the first tab 12 can be bent; then the electrode assembly 10 and the first adapter 40 can be installed as a whole in the housing 21 and the wall portion 23 can be assembled to the housing 21; then the first adapter 40 and the first electrode terminal 30 can be welded from the side of the first electrode terminal 30 away from the main body portion 11; finally, the first conductive part 60 can be assembled to the first electrode terminal 30 and the first conductive part 61 and the first electrode terminal 30 can be welded.

[0116] The first adapter 40 and the first electrode terminal 30 are welded from the outside, which helps to reduce the possibility of welding particles generated during the welding process falling into the housing 20, reducing the risk of internal short circuits and improving the reliability of the battery cell 6. The first conductive element 60 can cover the first welded part W1 exposed from the outside of the first electrode terminal 30, reducing the risk of corrosion of the first welded part W1.

[0117] In this embodiment, the first conductive element 60 is configured as a composite structure comprising a first conductive portion 61 and a second conductive portion 62 with different base metals. Electrical connection between the battery cell 6 and the external circuit can be achieved through welding the first conductive portion 61 to the first electrode terminal 30 and connecting the second conductive portion 62 to the busbar component. The first electrode terminal 30 is fixedly disposed on the wall portion 23, and the seal between the first electrode terminal 30 and the wall portion 23 does not depend on the first conductive element 60. This helps reduce the influence of the first conductive element 60 on the sealing interface between the first electrode terminal 30 and the wall portion 23, reducing the risk of seal failure between the first electrode terminal 30 and the wall portion 23 due to the breakage of the connection interface between the first conductive portion 61 and the second conductive portion 62, thereby improving the reliability of the battery cell 6.

[0118] In some embodiments, the battery cell 6 further includes an insulating support member disposed on the main body 11 and located between the main body 11 and the first adapter 40. The insulating support member can be used to support the first adapter 40, which is beneficial to improving the welding effect between the first adapter 40 and the first electrode terminal 30.

[0119] Alternatively, the insulating support can be an insulating film, an insulating bracket, or other components that can provide insulation and support.

[0120] In some embodiments, refer to Figure 6 , Figure 8 and Figure 9 The first electrode terminal 30 includes a terminal body 31, a first limiting portion 32, and a second limiting portion 33. The first limiting portion 32 is at least partially located on the side of the wall portion 23 away from the main body portion 11, and the second limiting portion 33 is at least partially located on the side of the wall portion 23 closer to the main body portion 11. At least a portion of the terminal body 31 is accommodated in the electrode lead-out hole 231 and connects the first limiting portion 32 and the second limiting portion 33. At least a portion of the sealing member 50 is located between the wall portion 23 and the second limiting portion 33 along the thickness direction X. The terminal body 31 is welded to the first adapter 40 to form a first welding portion W1, and a first conductive portion 61 is welded to the terminal body 31.

[0121] The terminal body 31 is inserted into the electrode lead-out hole 231, and a portion of the terminal body 31 can extend out of the electrode lead-out hole 231 along the thickness direction X. The first limiting part 32 can be connected to the end of the terminal body 31 away from the main body 11 along the thickness direction X, and the second limiting part 33 can be connected to the other end of the terminal body 31 close to the main body 11 along the thickness direction X.

[0122] Optionally, the terminal body 31, the first limiting part 32, and the second limiting part 33 are integrally formed. At least one of the first limiting part 32 and the second limiting part 33 can be formed by riveting.

[0123] The terminal body 31 can be a cylindrical structure or a columnar structure. The terminal body 31 has an outer peripheral surface surrounding its central axis, and the first limiting part 32 and the second limiting part 33 can be connected and protrude from the outer peripheral surface of the terminal body 31.

[0124] Optionally, the second limiting part 33 protruding from the outer peripheral surface of the terminal body 31 is larger than the first limiting part 32 protruding from the outer peripheral surface of the terminal body 31. This is beneficial to increase the size of the sealing member 50, thereby increasing the contact area between the second limiting part 33 and the sealing member 50 and improving the sealing effect.

[0125] Optionally, a first recess 311 is provided on the side of the terminal body 31 away from the main body 11, and the first adapter 40 is welded to the first bottom wall 312 of the first recess 311 to form a first welding part W1. The first welding part W1 is exposed on the side of the first electrode terminal 30 away from the main body 11 through the first recess 311.

[0126] Alternatively, the terminal body 31 is provided with a through hole that extends through the terminal body 31 in the thickness direction X. At least a portion of the first adapter 40 is accommodated in the through hole and welded to the wall of the through hole, thereby forming a first welded portion W1. The first welded portion W1 is exposed through the through hole on the side of the first electrode terminal 30 away from the main body 11.

[0127] At least a portion of the first limiting part 32 and at least a portion of the second limiting part 33 are respectively provided on both sides of the wall part 23 along the thickness direction X, which can limit the first electrode terminal 30 in the thickness direction X, which is beneficial to fixing the first electrode terminal 30 relative to the outer shell 20.

[0128] In some embodiments, refer to Figures 6 to 8 The terminal body 31 has a first recess 311 on the side away from the main body 11. The first conductive member 60 covers the first recess 311. The first bottom wall 312 of the first recess 311 is welded to the first adapter 40 and forms a first welding part W1. The first welding part W1 is exposed in the first recess 311.

[0129] The first recess 311 is open on the side of the terminal body 31 away from the main body 11. The first conductive member 60 covering the first recess 311 means that the first conductive member 60 covers the opening of the first recess 311 away from the main body 11.

[0130] In some examples, the first conductive element 60 is entirely housed within the first recess 311. In other examples, the first conductive element 60 is entirely disposed outside the first recess 311. In still other examples, a portion of the first conductive element 60 is housed within the first recess 311, while another portion is located outside the first recess 311.

[0131] When the terminal body 31 and the first adapter 40 are welded from the outside of the first electrode terminal 30, a portion of the first welded portion W1 may protrude from the bottom surface of the first recess 311. The first recess 311 can provide a accommodating space for the portion of the first welded portion W1 that protrudes from the bottom surface, which helps to reduce the risk of interference between the first welded portion W1 and the first conductive portion 61.

[0132] In this embodiment of the application, by providing a first recess 311, the first bottom wall 312 of the first recess 311 is closer to the side of the wall 23 facing the main body 11, which helps to reduce the welding difficulty of the first electrode terminal 30 and the first adapter 40 and improve the welding effect; it also helps to reduce the thickness of the part of the terminal body 31 used for welding with the first adapter 40, reduce the welding power, and reduce the welding heat generation.

[0133] In some embodiments, refer to Figure 6 and Figure 7 Along the thickness direction X, the first conductive part 61 and the first welding part W1 are spaced apart.

[0134] A portion of the first welded portion W1 protrudes from the bottom surface of the first recess 311 and is accommodated within the first recess 311.

[0135] The first conductive part 61 and the first welding part W1 are spaced apart, and the first welding part W1 does not contact the first conductive part 61, which helps to reduce the risk of interference between the first conductive part 61 and the first welding part W1 and improve the connection stability between the first conductive part 61 and the first electrode terminal 30.

[0136] In some embodiments, refer to Figure 6 and Figure 7 The first welded part W1 and the side wall of the first recess 311 are spaced apart.

[0137] The portion of the terminal body 31 surrounding the first recess 311 forms the sidewall of the first recess 311.

[0138] The first welding part W1 is not connected to the side wall of the first recess 311, which helps to reduce the welding difficulty of the first electrode terminal 30 and the first adapter 40 and improve assembly efficiency.

[0139] In some embodiments, refer to Figure 6 The terminal body 31 is provided with a first through hole 313, which penetrates the first bottom wall 312 of the first recess 311 along the thickness direction X. A portion of the first adapter 40 is accommodated in the first through hole 313 and welded to the terminal body 31 to form a first welded portion W1.

[0140] In the same plane perpendicular to the thickness direction X, the orthographic projection of the first through hole 313 lies within the orthographic projection of the first bottom wall 312. The orthographic projection area of ​​the first through hole 313 is smaller than the orthographic projection area of ​​the first bottom wall 312. The wall of the first through hole 313 is spaced apart from the sidewall of the first recess 311.

[0141] The terminal body 31 and the first adapter 40 are welded together by butt welding. The first welded portion W1 is connected to the wall of the first through hole 313 and the outer peripheral surface of the portion of the first adapter 40 that is received within the first through hole 313. Optionally, the first welded portion W1 is connected to the bottom surface of the first recess 311. Optionally, the first welded portion W1 is connected to the surface of the portion of the first adapter 40 that is received within the first through hole 313 near the first recess 311.

[0142] Optionally, the first welding part W1 is annular, which helps to improve the uniformity of the current sealing distribution between the first electrode terminal 30 and the first adapter 40.

[0143] In this embodiment, a first through hole 313 is formed in the first bottom wall 312. The portion of the first adapter 40 that is accommodated in the first through hole 313 is welded to the terminal body 31. This facilitates the determination of the welding position during the welding operation and reduces the welding difficulty. The first through hole 313 can limit the position of the first adapter 40, which helps to reduce the risk of relative displacement between the terminal body 31 and the first adapter 40 during the welding operation and improves welding stability.

[0144] In some embodiments, refer to Figure 7 The terminal body 31 has a second recess 314 on the side near the main body 11. The terminal body 31 includes a partition wall 315 that separates the first recess 311 and the second recess 314 along the thickness direction X. At least a portion of the first adapter 40 is accommodated in the second recess 314. The first adapter 40 is welded to the partition wall 315 to form a first welded portion W1.

[0145] In the same plane perpendicular to the thickness direction X, the orthographic projections of the first recess 311 and the second recess 314 partially overlap. The overlapping portion of the orthographic projections of the first recess 311 and the second recess 314 corresponds to the partition wall 315.

[0146] In some examples, in the same plane perpendicular to the thickness direction X, the projected area of ​​the first recess 311 is larger than the projected area of ​​the second recess 314, and the partition wall 315 forms the bottom wall of the second recess 314 and forms part of the first bottom wall 312 of the first recess 311.

[0147] In other examples, in the same plane perpendicular to the thickness direction X, the projected area of ​​the first recess 311 is smaller than the projected area of ​​the second recess 314, and the partition wall 315 forms the first bottom wall 312 of the first recess 311 and a part of the bottom wall of the second recess 314.

[0148] In some other examples, in the same plane perpendicular to the thickness direction X, the orthographic projection area of ​​the first recess 311 is equal to the orthographic projection area of ​​the second recess 314, and the orthographic projections of the first recess 311 and the second recess 314 exactly coincide. The partition wall 315 forms the first bottom wall 312 of the first recess 311 and the bottom wall of the second recess 314.

[0149] At least a portion of the first adapter 40, which is accommodated in the first recess 311, is stacked and welded to the partition wall 315. The first adapter 40 and the partition wall 315 are welded by through-welding.

[0150] By providing the second recess 314 in this embodiment, the thickness of the partition wall 315 used for welding with the first adapter 40 is reduced, thereby reducing the welding power of the first electrode terminal 30 and the first adapter 40, reducing welding heat generation, and improving welding stability.

[0151] In some embodiments, refer to Figure 7 In the same plane perpendicular to the thickness direction X, the orthographic projection range of the first recess 311 exceeds the orthographic projection range of the second recess 314.

[0152] In the same plane perpendicular to the thickness direction X, the orthographic projection range of the first bottom wall 312 of the first recess 311 exceeds the orthographic projection range of the partition wall 315.

[0153] Optionally, in the same plane perpendicular to the thickness direction X, the orthographic projection of the first bottom wall 312 and the orthographic projection of the partition wall 315 are both circles, and the radius of the orthographic projection of the first bottom wall 312 is greater than the radius of the orthographic projection of the partition wall 315.

[0154] The present application sets the orthographic projection range of the first recess 311 to be larger, which is beneficial to increase the distance between the first welding part W1 and the side wall of the first recess 311, reduce the welding difficulty, reduce the welding heat transferred to the side wall of the first recess 311, and reduce the risk of deformation of the terminal body 31.

[0155] In some embodiments, refer to Figure 6 , Figure 7 and Figure 9 The first conductive part 61 is at least partially accommodated in the first recess 311 and welded to the side wall of the first recess 311.

[0156] The first conductive part 61 may be entirely housed in the first recess 311, or only a portion of the first conductive part 61 may be housed in the first recess 311. The other portion of the first conductive part 61 may be located on the side of the first recess 311 away from the main body 11.

[0157] The sidewalls of the first conductive part 61 and the first recess 311 can be welded by butt welding.

[0158] The first conductive portion 61 is at least partially accommodated in the first recess 311. The first conductive portion 61 and the first electrode terminal 30 can share a portion of the space in the thickness direction X, which helps to save the space occupied by the battery cell 6 in the thickness direction X and improve the energy density of the battery cell 6.

[0159] In some embodiments, refer to Figure 8 and Figure 10 The first recess 311 includes a first sub-recess 3111 and a second sub-recess 3112. The first sub-recess 3111 and the second sub-recess 3112 are arranged along the direction from the main body 11 toward the wall 23. In the same plane perpendicular to the thickness direction X, the orthographic projection range of the second sub-recess 3112 exceeds the orthographic projection range of the first sub-recess 3111. The first conductive part 61 is at least partially accommodated in the second sub-recess 3112 and is welded to the sidewall of the second sub-recess 3112.

[0160] Along the thickness direction X, the first sub-recess 3111 is closer to the main body 11 than the second sub-recess 3112. In the same plane perpendicular to the thickness direction X, the projected area of ​​the second sub-recess 3112 is larger than the projected area of ​​the first sub-recess 3111.

[0161] The first conductive portion 61 is located on the side of the first sub-recess 3111 near the second sub-recess 3112, and is at least partially accommodated in the second sub-recess 3112. In the same plane perpendicular to the thickness direction X, the orthographic projection of the first sub-recess 3111 lies within the orthographic projection of the first conductive portion 61.

[0162] The first sub-recess 3111 includes a first inner peripheral surface 3111a, which surrounds the internal space of the first sub-recess 3111. The second sub-recess 3112 includes a second inner peripheral surface 3112a, which surrounds the internal space of the second sub-recess 3112.

[0163] Optionally, the first recess 311 includes a first stepped surface 311a, which connects the first inner peripheral surface 3111a and the second inner peripheral surface 3112a. A portion of the first conductive portion 61 may be supported on the first stepped surface 311a.

[0164] Alternatively, the first inner circumferential surface 3111a intersects with the second inner circumferential surface 3112a, the second inner circumferential surface 3112a is inclined relative to the thickness direction X, and a portion of the first conductive part 61 can be supported on the second inner circumferential surface 3112a.

[0165] In this embodiment of the application, by setting a first sub-recess 3111 and a second sub-recess 3112 of different sizes, a portion of the surface of the first recess 311 can support the first conductive part 61, which is beneficial to improving the support stability of the first conductive part 61 and the connection stability between the first conductive part 61 and the terminal body 31.

[0166] In some embodiments, refer to Figure 8 and Figure 10 The first recess 311 includes a third sub-recess 3113. The first sub-recess 3111, the second sub-recess 3112, and the third sub-recess 3113 are arranged sequentially along the direction from the main body 11 toward the wall 23. In the same plane perpendicular to the thickness direction X, the orthographic projection range of the third sub-recess 3113 exceeds the orthographic projection range of the second sub-recess 3112. The first conductive part 61 is welded to the terminal body 31 to form a second welding part W2. The second welding part W2 is connected to the side of the second sub-recess 3112 and the first outer peripheral surface 61a of the first conductive part 61. A portion of the second welding part W2 is accommodated in the third sub-recess 3113.

[0167] The third sub-recess 3113 includes a third inner peripheral surface 3113a, which surrounds the internal space of the third sub-recess 3113. The first recess 311 includes a second stepped surface 311b, which connects the third inner peripheral surface 3113a and the second inner peripheral surface 3112a. The second welded portion W2 may also be connected to the second stepped surface 311b.

[0168] Alternatively, the first conductive part 61 and the terminal body 31 can be welded by butt welding.

[0169] Optionally, the second welding part W2 is annular, which helps to improve the uniformity of the current sealing distribution between the first electrode terminal 30 and the first conductive part 60, and also helps to improve the sealing performance between the terminal body 31 and the first conductive part 61.

[0170] Optionally, in the direction from the main body 11 to the wall 23, the second welding part W2 does not extend beyond the third sub-recess 3113, which helps to reduce the possibility of the second welding part W2 being worn and reduces the risk of connection failure between the first electrode terminal 30 and the first conductive element 60.

[0171] During welding, the third sub-recess 3113 provides clearance for the molten portion of the first conductive part 61 and the terminal body 31, allowing at least part of the molten portion to flow away from the first outer peripheral surface 61a of the first conductive part 61. This helps reduce the size of the second weld portion W2 formed after the molten portion solidifies along the thickness direction X, reducing the possibility that the second weld portion W2 will extend beyond the third sub-recess 3113, and lowering the risk of wear on the second weld portion W2 leading to connection failure between the first electrode terminal 30 and the first conductive element 60. The combination of the first weld portion W1 and the second weld portion W2 provides a double sealing effect, which helps improve the sealing performance of the battery cell 6.

[0172] In some embodiments, refer to Figures 6 to 9 The first conductive portion 61 includes a first conductive sub-portion 611 and a second conductive sub-portion 612. The first conductive sub-portion 611 and the second conductive portion 62 are stacked in the direction from the main body portion 11 toward the wall portion 23. The second conductive sub-portion 612 surrounds the first conductive sub-portion 611 and protrudes from the second outer peripheral surface 62a of the second conductive portion 62. The second conductive sub-portion 612 is welded to the side wall of the first recess 311. A third recess 613 is provided on the side of the second conductive sub-portion 612 facing the second conductive portion 62.

[0173] Optionally, the third recess 613 is an annular groove surrounding the first conductive electronic portion 611.

[0174] Alternatively, the third recess 613 can be formed by locally thinning the second conductive portion 612 through stamping, cutting or other suitable means.

[0175] The third recess 613 can provide stress relief space, which helps to alleviate and release the stress on the first conductive part 61 and the terminal body 31 during welding, and reduces the risk of breakage of the first conductive part 61 and the terminal body 31.

[0176] In some embodiments, the thickness of the second limiting portion 33 is greater than the thickness of the first limiting portion 32.

[0177] The thickness of the first limiting part 32 is relatively small, which helps to reduce the size of the first limiting part 32 in the thickness direction X, reduce the space occupied by the battery cell 6 in the thickness direction X, and improve its energy density.

[0178] The second limiting part 33 has a larger thickness, which on the one hand helps to improve the structural strength of the first electrode terminal 30 and improve the stability of the first electrode terminal 30 relative to the wall 23; on the other hand, the second limiting part 33 can share part of the space in the thickness direction X with the first electrode tab 12 and / or the first adapter 40, reducing the extra space occupied in the thickness direction X.

[0179] In some embodiments, refer to Figures 6 to 8 The first adapter 40 includes an adapter body 41, a first protrusion 42, and a second protrusion 43. The adapter body 41 is connected between the first protrusion 42 and the second protrusion 43 along a first direction Y, which is perpendicular to the thickness direction X. At least a portion of the adapter body 41 is located on the side of the second limiting portion 33 away from the wall portion 23. Both the first protrusion 42 and the second protrusion 43 protrude from the surface of the adapter body 41 facing the second limiting portion 33. The first protrusion 42 is welded to the terminal body 31 to form a first welding portion W1. The second protrusion 43 is located on the side of the second limiting portion 33 along the first direction Y. At least a portion of the first electrode tab 12 is located on the side of the second protrusion 43 near the body portion 11 and is connected to the second protrusion 43.

[0180] In some examples, at least a portion of the first protrusion 42 is received in the first through hole 313 and welded to the terminal body 31. The first welded portion W1 is connected to the outer peripheral surface of the first protrusion 42 and the wall of the first through hole 313.

[0181] In other examples, a portion of the first protrusion 42 is stacked and welded to the partition wall 315. A first welded portion W1 is attached to the surface of the first protrusion 42 facing the partition wall 315. Along the thickness direction X, the second limiting portion 33 and the transition body 41 are spaced apart to reduce interference and facilitate the welding of the first protrusion 42 to the partition wall 315.

[0182] In some examples, the second protrusion 43 is a single portion and is located on either side of the second limiting portion 33 along the first direction Y.

[0183] In other examples, there are two second protrusions 43, which are respectively provided on both sides of the second limiting part 33 along the first direction Y.

[0184] The second protrusion 43 protrudes from the adapter body 41 towards the wall portion 23. The surface of the adapter body 41 facing the main body portion 11 is closer to the main body portion 11 than the surface of the second protrusion 43 facing the main body portion 11. A receiving space can be formed on the side of the second protrusion 43 facing the main body portion 11 to accommodate at least a portion of the first electrode tab 12. The second protrusion 43 and the first electrode tab 12 can share a portion of the space in the thickness direction X with the second limiting portion 33, which is beneficial for improving space utilization and increasing the energy density of the battery cell 6.

[0185] In other embodiments, reference is made to Figure 11 Along the thickness direction X, a portion of the first tab 12 is located between the second limiting part 33 and the first adapter 40, and is connected to the first adapter 40 and the second limiting part 33.

[0186] A portion of the first tab 12 can be folded to the side of the first adapter 40 away from the main body 11. The bent portion of the first tab 12 can be located on the side of the first adapter 40 along the first direction Y, and share the space in the thickness direction X with the first adapter 40, which is beneficial to improving space utilization and increasing energy density.

[0187] The first tab 12 is electrically connected to the first adapter 40 and the second limiting part 33. Overcurrent paths are formed between the first tab 12 and the first adapter 40, as well as between the first tab 12 and the second limiting part 33. Some current can be directly transmitted between the first tab 12 and the first electrode terminal 30, which is beneficial to improving the overcurrent capacity of the battery cell 6.

[0188] In some embodiments, refer to Figure 6 and Figure 7 The first electrode terminal 30 includes a first surface 30a facing away from the main body 11 along the thickness direction X, and at least a portion of the second conductive portion 62 extends beyond the first surface 30a along the direction from the main body 11 toward the wall portion 23.

[0189] Optionally, the first surface 30a is the surface of the first limiting portion 32 facing away from the main body portion 11.

[0190] The surface of the second conductive part 62 facing away from the main body 11 is further away from the main body 11 than the first surface 30a. This helps to reduce the risk of interference between the busbar and the first electrode terminal 30 when connecting the busbar and the second conductive part 62, and improves the connection reliability of the busbar and the second conductive part 62.

[0191] In some embodiments, the first electrode terminal 30 includes a first surface 30a facing away from the main body portion 11 along the thickness direction X. The connection surface 63 of the first conductive portion 61 and the second conductive portion 62 is closer to the main body portion 11 than the first surface 30a, which helps to reduce the possibility of wear or impact on the connection surface 63, reduce the risk of breakage of the connection surface 63, and improve the connection stability of the first conductive portion 61 and the second conductive portion 62.

[0192] In some embodiments, refer to Figure 6 and Figure 7The wall portion 23 includes a second surface 23a facing away from the main body portion 11, and the first conductive member 60 is further away from the main body portion 11 than the second surface 23a. The first conductive member 60 is entirely located outside the housing 20, which is beneficial for welding between the first conductive portion 61 and the first electrode terminal 30, and also helps to increase the distance between the bus component and the wall portion 23, reducing the risk of short circuit caused by the bus component and the wall portion 23 overlapping.

[0193] In some embodiments, the first conductive portion 61 and the second conductive portion 62 are connected by at least one of cold rolling, hot rolling, explosive bonding, and explosive rolling. This improves the connection strength and stability between the first conductive portion 61 and the second conductive portion 62, and reduces the risk of separation of the connection surfaces 63 of the first conductive portion 61 and the second conductive portion 62.

[0194] In some embodiments, refer to Figure 3 and Figure 12 The electrode assembly 10 includes a second tab 13 extending from the main body 11, the second tab 13 having the opposite polarity to the first tab 12. The battery cell also includes a second electrode terminal 70 and a second adapter 80, the second electrode terminal 70 being electrically connected to the second tab 13 and the second adapter 80. The base metal of the second electrode terminal 70 is the same as the base metal of the second conductive portion 62.

[0195] The first electrode 12 and the second electrode 13 can be led out from the same end of the main body 11, or they can be led out from different ends of the main body 11. Optionally, both the first electrode 12 and the second electrode 13 are led out from the end of the main body 11 facing the wall portion 23.

[0196] Optionally, the first electrode 12 is the negative electrode, and the second electrode 13 is the positive electrode. Both the second electrode terminal 70 and the second conductive part 62 can be made of aluminum or an aluminum alloy. The base metal of the second electrode terminal 70 and the base metal of the second conductive part 62 can both be aluminum.

[0197] The second electrode terminal 70 is used to connect directly or indirectly to the busbar component. The base metal of the second electrode terminal 70 is the same as the base metal of the second conductive part 62. The second conductive part 62 of one battery cell 6 and the second electrode terminal 70 of another battery cell 6 can be welded to the same busbar component, which is beneficial to realize the series connection between the two battery cells 6 and reduce the connection difficulty.

[0198] In some embodiments, refer to Figure 12The second electrode terminal 70 has a fourth recess 71 on the side away from the main body 11. The second electrode terminal 70 has a second through hole 72, which penetrates the second bottom wall 73 of the fourth recess 71 along the thickness direction X. At least a portion of the second adapter 80 is accommodated in the second through hole 72 and welded to the second electrode terminal 70 to form a third welded portion W3, which is exposed in the fourth recess 71. The battery cell 6 includes a second conductive element 90, which is welded to the second electrode terminal 70 and used for connection with the busbar component. Along the thickness direction X, the second conductive element 90 covers the fourth recess 71.

[0199] The portion of the second adapter 80 housed in the second through hole 72 is welded to the second electrode terminal 70 by butt welding. The third welded portion W3 emerges and is exposed from the fourth recess 71.

[0200] During assembly, the second electrode tab 13 can be connected to the second adapter 80 first, and the second electrode tab 13 can be bent; then the electrode assembly 10 and the first adapter 40 can be installed as a whole in the housing 21, and the wall portion 23 can be assembled to the housing 21; then the second adapter 80 and the second electrode terminal 70 can be welded from the side of the second electrode terminal 70 away from the main body portion 11; finally, the second conductive element 90 can be assembled to the second electrode terminal 70, and the second conductive element 90 and the second electrode terminal 70 can be welded.

[0201] The second adapter 80 and the second electrode terminal 70 are welded from the outside, which helps to reduce the possibility of welding particles generated during the welding process falling into the housing 20, reducing the risk of internal short circuits and improving the reliability of the battery cell 6. The second conductive element 90 can cover the third welded part W3 exposed from the outside of the second electrode terminal 70, reducing the risk of corrosion of the third welded part W3.

[0202] Optionally, the structure of the second adapter 80 is the same as that of the first adapter 40, which will not be described in detail here.

[0203] In some embodiments, the base metal of the first conductive portion 61 and the base metal of the first electrode terminal 30 are both copper. The base metal of the second conductive portion 62 is aluminum.

[0204] Accordingly, the base metal of the first adapter 40 is copper, and the base metal of the second conductive part 62 is aluminum. The base metals of the second electrode terminal 70, the second adapter 80, and the second conductive part 90 are all aluminum.

[0205] In some embodiments, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening 211, and the end cap 22 being connected to the housing 21 and covering the opening 211. The wall portion 23 is the end cap 22.

[0206] The end cap 22 can be attached to the housing 21 by welding, snap-fitting, gluing or other suitable means.

[0207] The housing 21 and the end cap 22 are separate structures. The first electrode terminal 30 is located on the end cap 22. During assembly, the electrode assembly 10 and the first adapter 40 can be installed into the housing 21 through the opening 211. Then, the end cap 22 is closed on the opening 211, and the first adapter 40 and the first electrode terminal 30 are welded on. This simplifies the assembly operation and reduces the assembly difficulty.

[0208] According to a second aspect of this application, an embodiment of this application provides a battery device 2, referring to... Figure 2 and Figure 13 The battery device 2 includes a busbar 7 and a battery cell 6 provided according to some embodiments of the first aspect of this application. The base metal of the busbar 7 is the same as the base metal of the second conductive portion 62, and the busbar 7 is welded to the second conductive portion 62.

[0209] Optionally, the first electrode tab 12 is a negative electrode tab, and the negative electrode tab is made of copper. The first electrode terminal 30 and the first adapter 40 can be made of copper or copper alloy. The base metal of the first electrode terminal 30, the first adapter 40, and the first conductive part 61 are all copper, which facilitates welding. The second conductive part 62 and the busbar 7 can be made of aluminum or aluminum alloy. The base metal of the second conductive part 62 and the busbar 7 is aluminum, which facilitates welding between the two.

[0210] In this embodiment, the base metal of the busbar component 7 and the base metal of the second conductive part 62 are set to be the same, which is beneficial for welding the two and improves welding efficiency and welding effect.

[0211] In some embodiments, the battery device 2 includes a plurality of battery cells 6. A busbar component 7 is welded to a second conductive portion 62 of one battery cell 6 and a second conductive element 90 of another battery cell 6.

[0212] According to a third aspect of this application, embodiments of this application also provide an electrical device, which includes a battery device 2 provided according to any embodiment of the second aspect of this application, the battery device 2 being used to provide electrical energy.

[0213] The battery cell 6 provided in this embodiment includes an electrode assembly 10, a housing 20, a first electrode terminal 30, a first adapter 40, a seal 50, and a first conductive element 60. The housing 20 includes a wall portion 23, which has an electrode lead-out hole 231. The electrode assembly 10 is housed within the housing 20 and includes a main body portion 11 and a first tab 12 extending from the main body portion 11. The first adapter 40 is connected to the first tab 12. The first electrode terminal 30 is fixedly disposed on the wall portion 23. The first electrode terminal 30 includes a terminal body 31, a first limiting portion 32, and a second limiting portion 33. The first limiting portion 32 is at least partially disposed on the side of the wall portion 23 away from the main body portion 11, and the second limiting portion 33 is at least partially disposed on the side of the wall portion 23 close to the main body portion 11. At least a portion of the terminal body 31 is housed in the electrode lead-out hole 231 and connected to the first limiting portion 32 and the second limiting portion 33. Along the thickness direction X, at least a portion of the sealing member 50 is disposed between the wall portion 23 and the second limiting portion 33. A first recess 311 is provided on the side of the terminal body 31 away from the main body portion 11. A first conductive member 60 covers the first recess 311. The terminal body 31 has a first through hole 313, which penetrates the first bottom wall 312 of the first recess 311 along the thickness direction X. A portion of the first adapter 40 is accommodated in the first through hole 313 and welded to the terminal body 31 to form a first weld portion W1, which is exposed in the first recess 311. The first conductive member 61 is welded to the terminal body 31. Along the thickness direction X of the wall portion 23, at least a portion of the sealing member 50 is disposed between the first electrode terminal 30 and the wall portion 23. The first conductive member 60 is disposed on the side of the first weld portion W1 away from the main body portion 11 and serves to cover the first weld portion W1. The first conductive element 60 includes a first conductive portion 61 and a second conductive portion 62 connected to each other. The base metals of the first conductive portion 61 and the second conductive portion 62 are different. The base metal of the first conductive portion 61 is the same as that of the first electrode terminal 30. The first conductive portion 61 is soldered to the first electrode terminal 30. Along the thickness direction X of the wall portion 23, at least a portion of the second conductive portion 62 is located on the side of the first conductive portion 61 away from the main body portion 11 and is used for connection with the busbar component.

[0214] 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 casing includes a wall portion, wherein the wall portion is provided with electrode lead-out holes; An electrode assembly, housed within the housing, the electrode assembly comprising a main body and a first tab extending from the main body; The first adapter is welded to the first electrode tab; A first electrode terminal is fixedly disposed on the wall portion and partially accommodated in the electrode lead-out hole. The first electrode terminal is welded to the first adapter to form a first weld portion, which is exposed on the side of the first electrode terminal away from the main body portion. A sealing element, at least a portion of which is disposed between the first electrode terminal and the wall portion along the thickness direction of the wall portion; as well as A first conductive element is disposed on the side of the first weld portion away from the main body portion and is used to cover the first weld portion. The first conductive element includes a first conductive portion and a second conductive portion connected to each other. The base metals of the first conductive portion and the second conductive portion are different. The base metals of the first conductive portion and the first electrode terminal are the same. The first conductive portion is welded to the first electrode terminal. Along the thickness direction of the wall portion, at least a portion of the second conductive portion is located on the side of the first conductive portion away from the main body portion and is used to weld to the busbar component. The material of the busbar component is different from the material of the first tab. The first electrode terminal includes a terminal body, at least a portion of which is accommodated in the electrode lead-out hole. A first recess is provided on the side of the terminal body away from the main body portion. The first conductive element covers the first recess and is welded to the terminal body. The first bottom wall of the first recess is welded to the first adapter and forms the first weld portion. The first weld portion is exposed in the first recess.

2. The battery cell according to claim 1, characterized in that, The first electrode terminal includes a first limiting portion and a second limiting portion. The first limiting portion is at least partially disposed on the side of the wall portion away from the main body portion, and the second limiting portion is at least partially disposed on the side of the wall portion close to the main body portion. The terminal body connects the first limiting portion and the second limiting portion. Along the thickness direction, at least a portion of the seal is disposed between the wall portion and the second limiting portion.

3. The battery cell according to claim 2, characterized in that, Along the thickness direction, the first conductive portion and the first welded portion are spaced apart.

4. The battery cell according to claim 2 or 3, characterized in that, The first welded portion and the sidewall of the first recessed portion are spaced apart.

5. The battery cell according to claim 2 or 3, characterized in that, The terminal body is provided with a first through hole, and the first through hole penetrates the first bottom wall of the first recess along the thickness direction; A portion of the first adapter is accommodated in the first through hole and welded to the terminal body to form the first welded portion.

6. The battery cell according to claim 2 or 3, characterized in that, The terminal body has a second recess on the side near the main body portion, and the terminal body includes a partition wall that separates the first recess and the second recess along the thickness direction; At least a portion of the first adapter is accommodated in the second recess, and the first adapter is welded to the partition wall to form the first welded portion.

7. The battery cell according to claim 6, characterized in that, In the same plane perpendicular to the thickness direction, the orthographic projection range of the first recess exceeds the orthographic projection range of the second recess.

8. The battery cell according to claim 2 or 3, characterized in that, The first conductive portion is at least partially accommodated in the first recess and welded to the sidewall of the first recess.

9. The battery cell according to claim 2 or 3, characterized in that, The first recess includes a first sub-recess and a second sub-recess. The first sub-recess and the second sub-recess are arranged along the direction from the main body to the wall. In the same plane perpendicular to the thickness direction, the orthographic projection range of the second sub-recess exceeds the orthographic projection range of the first sub-recess. The first conductive portion is at least partially accommodated in the second sub-recess and is welded to the sidewall of the second sub-recess.

10. The battery cell according to claim 9, characterized in that, The first recess includes a third sub-recess. The first sub-recess, the second sub-recess, and the third sub-recess are arranged sequentially along the direction from the main body to the wall. In the same plane perpendicular to the thickness direction, the orthographic projection range of the third sub-recess exceeds the orthographic projection range of the second sub-recess. The first conductive part is welded to the terminal body to form a second welded part. The second welded part is connected to the side of the second sub-recess and the first outer peripheral surface of the first conductive part. A portion of the second welded part is accommodated in the third sub-recess.

11. The battery cell according to claim 8, characterized in that, The first conductive portion includes a first conductive sub-part and a second conductive sub-part. The first conductive sub-part and the second conductive portion are stacked in a direction from the main body portion to the wall portion. The second conductive sub-part surrounds the first conductive sub-part and protrudes from the second outer peripheral surface of the second conductive portion. The second conductive sub-part is welded to the side wall of the first recess. The second conductive part has a third recess on the side facing the second conductive part.

12. The battery cell according to claim 2 or 3, characterized in that, The thickness of the second limiting part is greater than the thickness of the first limiting part.

13. The battery cell according to claim 2 or 3, characterized in that, The first adapter includes an adapter body, a first protrusion, and a second protrusion. Along a first direction, the adapter body is connected between the first protrusion and the second protrusion, and the first direction is perpendicular to the thickness direction. At least a portion of the adapter body is disposed on the side of the second limiting portion away from the wall portion. The first protrusion and the second protrusion both protrude from the surface of the adapter body facing the second limiting portion. The first protrusion is welded to the terminal body to form the first welding portion. The second protrusion is disposed on the side of the second limiting portion along the first direction. At least a portion of the first tab is located on the side of the second protrusion near the main body and is connected to the second protrusion.

14. The battery cell according to claim 2 or 3, characterized in that, Along the thickness direction, a portion of the first electrode tab is located between the second limiting portion and the first adapter, and is connected to the first adapter and the second limiting portion.

15. The battery cell according to any one of claims 1-3, characterized in that, The first electrode terminal includes a first surface facing away from the main body in the thickness direction, and at least a portion of the second conductive portion extends beyond the first surface in the direction from the main body to the wall.

16. The battery cell according to any one of claims 1-3, characterized in that, The first conductive part and the second conductive part are connected by at least one of cold rolling, hot rolling, explosive composite method, and explosive rolling method.

17. The battery cell according to any one of claims 1-3, characterized in that, The electrode assembly includes a second electrode tab extending from the main body, the second electrode tab having the opposite polarity to the first electrode tab; The battery cell further includes a second electrode terminal and a second adapter, wherein the second electrode terminal is electrically connected to the second tab and the second adapter; The base metal of the second electrode terminal is the same as the base metal of the second conductive part.

18. The battery cell according to claim 17, characterized in that, The second electrode terminal has a fourth recess on the side away from the main body, and the second electrode terminal has a second through hole. The second through hole penetrates the second bottom wall of the fourth recess along the thickness direction. At least a portion of the second adapter is accommodated in the second through hole and welded to the second electrode terminal to form a third welded portion. The third welded portion is exposed in the fourth recess. The battery cell includes a second conductive element, which is welded to the second electrode terminal and used to connect to the busbar component. Along the thickness direction, the second conductive element covers the fourth recess.

19. The battery cell according to any one of claims 1-3, characterized in that, The base metal of the first conductive part and the base metal of the first electrode terminal are both copper; The base metal of the second conductive part is aluminum.

20. The battery cell according to any one of claims 1-3, characterized in that, The housing includes a shell and an end cap, the shell having an opening, and the end cap being connected to the shell and covering the opening; The wall portion is the end cap.

21. A battery device, characterized in that, include: The battery cell according to any one of claims 1-20; as well as A busbar component, wherein the base metal of the busbar component is the same as the base metal of the second conductive part, and the busbar component is welded to the second conductive part.

22. An electrical appliance, characterized in that, Includes the battery device according to claim 21, the battery device being used to provide electrical energy.

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