Battery cells, battery devices and electrical equipment

Abstract

The present application discloses a battery cell, a battery device and an electrical device. The battery cell includes a housing, an electrode assembly, a first electrode terminal and a first adapter. The electrode assembly includes a main body and a first pole lug. The first electrode terminal includes a first terminal part and a second terminal part with different base metals. The second terminal part is at least partially located on the side of the first terminal part away from the electrode assembly. The first adapter connects the first pole lug and the first terminal part. The first adapter has the same base metal as the first terminal part. The first adapter is at least partially located on the side of the first terminal part facing the main body, and is abutted against and welded with the first terminal part to form a first welding part. A part of the first welding part is exposed on the side of the first electrode terminal away from the electrode assembly; a first recess is provided on the side of the first terminal part facing the main body, and a part of the first welding part is provided on the bottom wall of the first recess. The present application can reduce the risk of short circuit and the difficulty of welding, and improve the reliability of the battery cell.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and in particular relates to a battery cell, a battery device and an electrical equipment. Background Art

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

[0003] In the development of battery technology, how to improve the reliability of battery cells is a research direction in battery technology. Summary of the invention

[0004] The embodiments of the present application provide a battery cell, a battery device and an electrical equipment, which are beneficial to improving the reliability of the battery cell.

[0005] According to a first aspect of the present application, the present application provides a battery cell, which includes a housing, an electrode assembly, a first electrode terminal and a first adapter. The housing includes a first wall. The electrode assembly is accommodated in the housing, and the electrode assembly includes a main body and a first pole ear led out from the main body. The first electrode terminal is arranged on the first wall, and the first electrode terminal includes a first terminal part and a second terminal part connected to each other, and the base metal of the first terminal part is different from the base metal of the second terminal part. In the thickness direction of the first wall, at least part of the second terminal part is located on the side of the first terminal part away from the electrode assembly and is used to connect with the current collection component. The first adapter connects the first pole ear and the first terminal part, and the base metal of the first adapter is the same as the base metal of the first terminal part. In the thickness direction of the first wall, the first adapter is at least partially located on the side of the first terminal part facing the main body, and is abutted and welded with the first terminal part to form a first welding part, and a part of the first welding part is exposed on the side of the first electrode terminal away from the electrode assembly along the thickness direction. A first recess is provided on the side of the first terminal part facing the main body, and a part of the first welding part is provided on the bottom wall of the first recess.

[0006] In the embodiment of the present application, the first pole ear and the first adapter can be connected first and then inserted into the shell, and then the first adapter and the first terminal part are welded. The first terminal part and the first adapter are penetrated by heating the abutting part of the first terminal part and the first adapter from the outside of the first electrode terminal by laser or other means, which can reduce the possibility of welding particles generated during welding falling into the side of the first adapter facing the electrode assembly, reduce the risk of internal short circuit of the battery cell, and help improve the reliability of the battery cell. In addition, the length of the first pole ear led out from the main body can be shortened, saving the space required for bending the first pole ear, which is conducive to improving the energy density of the battery cell; it can also reduce the external force pulling on the first pole ear and reduce the risk of cracking of the first pole ear. The bottom wall of the first recess is closer to the side of the first wall facing away from the main body in the thickness direction, which can shorten the distance between the welding device and the bottom wall of the first recess, which is conducive to reducing the difficulty of welding, reducing the diffusion of welding heat, and reducing the adverse effects on other components.

[0007] In some embodiments, the first terminal portion and the second terminal portion are stacked along the thickness direction of the first wall, and the second terminal portion is located on the side of the first wall away from the main body portion along its own thickness direction. In the thickness direction, there is no thickness overlap between the second terminal portion and the first wall, which can increase the distance between the surface of the second terminal portion facing away from the first wall and the first wall. After the second terminal portion is connected to the busbar component, the second terminal portion can prop up the busbar component to a certain height along the thickness direction to increase the spacing between the busbar component and the first wall, which is conducive to reducing the risk of overlap between the busbar component and the first wall.

[0008] In some embodiments, the second terminal portion is provided with a first through hole, and the first through hole penetrates the second terminal portion along the thickness direction of the first wall; in the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first welding portion is at least partially located within the orthographic projection of the first through hole. The first through hole can provide an avoidance space for the welding operation between the first terminal portion and the first adapter. On the one hand, it is conducive to reducing the influence of the second terminal portion on the welding operation. On the other hand, it can also reduce the thickness of the welding area of ​​the first electrode terminal used to weld the first adapter, which is conducive to reducing the welding power and reducing the heat generated by welding. In addition, the first through hole can also provide certain indication and positioning functions for the welding operation, which is conducive to limiting the range of the first terminal portion that can be used for welding to the area with thinner thickness, thereby improving the welding effect.

[0009] In some embodiments, in the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first through hole is located within the orthographic projection of the first recess. When the first terminal portion and the first adapter are welded through the first through hole, the possibility of the weld mark exceeding the bottom wall of the first recess can be reduced, and the first welding portion is not easily formed in the thicker portion of the first terminal portion, which is conducive to improving the welding effect.

[0010] In some embodiments, in the same plane perpendicular to the thickness direction of the first wall, the orthographic projection area of ​​the first recess is larger than the orthographic projection area of ​​the first through hole. When the first terminal portion and the first adapter are welded through the first through hole, even if part of the weld mark extends to the periphery of the second wall, this part of the weld mark is not likely to exceed the bottom wall of the first recess, and the first welding portion is not likely to be formed in the thicker portion of the first terminal portion, which is conducive to improving the welding effect.

[0011] In some embodiments, the first terminal portion has a second wall, and along the thickness direction of the first wall, the second wall is located between the first through hole and the first recess; a portion of the first welding portion is disposed on the second wall. The second wall is disposed corresponding to at least a portion of the first recess, and the thickness of the second wall is relatively thin. The first adapter is welded to the second wall, which is conducive to reducing the difficulty of welding, reducing the requirements for welding power, and improving the welding effect.

[0012] In some embodiments, a second recess is provided on the side of the first terminal portion facing away from the electrode assembly, and in the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first recess at least partially overlaps with the orthographic projection of the second recess; along the thickness direction of the first wall, the second wall is located between the first recess and the second recess. Thus, the thickness of the second wall can be further reduced, which is conducive to further improving the welding effect.

[0013] In some embodiments, in the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second recess is located within the orthographic projection of the first recess. During the welding process of the first terminal portion and the first adapter, the second recess can have a certain indication effect on the welding area, and the orthographic projection of the second recess is located within the orthographic projection of the first recess, which is conducive to reducing the possibility of the first welding portion exceeding the second wall. In addition, the size of the second recess is not too large, which is conducive to increasing the flow area of ​​the first terminal portion and improving its flow capacity.

[0014] In some embodiments, a second recess is provided on a side of the first terminal portion facing away from the electrode assembly, and a portion of the first welding portion is provided on a bottom wall of the second recess. The bottom wall of the second recess is relatively thin, which is conducive to reducing the difficulty of welding, reducing the requirements for welding power, improving the welding effect, and reducing welding heat generation.

[0015] In some embodiments, in the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second recess is located within the orthographic projection of the first through hole. Thus, the size of the second recess can be reduced, the area of ​​the first terminal portion used for connection with the second terminal portion can be increased, and the possibility of the second terminal portion being partially suspended can be reduced, which is conducive to enhancing the connection strength between the first terminal portion and the second terminal portion. In addition, the second recess is located on the outside of the first terminal portion facing the first through hole, and the position of the second recess is easy to obtain from the outside. Even if the size of the second recess is relatively small, it is easy to determine the position of the welding area and reduce the possibility of the welding mark exceeding the second wall.

[0016] In some embodiments, in the same plane perpendicular to the thickness direction of the first wall, the orthographic projection area of ​​the first through hole is larger than the orthographic projection area of ​​the second recess. The size of the second recess is relatively small, which is conducive to increasing the flow area of ​​the first terminal part and improving its flow capacity. In addition, the boundary of the second recess can be exposed, and the boundary of the second recess can be used as a reference, which is more conducive to determining the position of the welding area and reducing the risk of welding misalignment.

[0017] In some embodiments, the first welding portion is spaced apart from the hole wall of the first through hole, thereby facilitating the welding operation between the first terminal portion and the first adapter and reducing the heat transferred to the second terminal portion during welding, thereby reducing the risk of deformation of the second terminal portion.

[0018] In some embodiments, in the radial direction of the first through hole, the minimum spacing between the first welding portion and the hole wall of the first through hole is d, 2mm≤d≤8mm. When d is greater than or equal to 2mm, the distance between the first welding portion and the hole wall is not too small, which is beneficial to reduce the heat transferred to the second terminal portion during welding and reduce the risk of deformation of the second terminal portion; when d is less than or equal to 8mm, it is beneficial to increase the size of the first welding portion within a limited range and improve the welding strength between the first terminal portion and the first adapter.

[0019] In some embodiments, the first adapter includes an adapter body and a convex portion, the adapter body is disposed on a side of the first wall facing the main body and connected to the first pole ear, the convex portion protrudes from the surface of the adapter body facing the first wall and abuts against the first terminal portion, and the first welding portion connects the convex portion and the first terminal portion. The convex portion protrudes in a direction away from the main body relative to the adapter body, and the welding area between the convex portion and the first terminal portion is closer to the outer side of the first wall away from the main body, which is conducive to reducing the difficulty of the welding operation and improving the welding efficiency. In addition, the convex portion can also enhance the overall strength of the first adapter to a certain extent and reduce the risk of the first adapter being deformed by heat during the welding process.

[0020] In some embodiments, the first adapter is provided with a third recess facing the main body at a position corresponding to the convex portion, and the third recess is recessed relative to the surface of the adapter body facing the main body. Thus, the thickness of the top wall of the convex portion can be reduced, which is conducive to reducing the difficulty of welding between the convex portion and the first terminal portion, reducing the requirements for welding power, improving the welding effect between the two, and reducing welding heat generation.

[0021] In some embodiments, at least part of the convex portion is accommodated in the first concave portion, the top surface of the convex portion abuts against the bottom surface of the first concave portion, and the first welding portion connects the top surface of the convex portion and the bottom surface of the first concave portion. Thus, the thickness of the region of the first terminal portion used for welding with the convex portion can be reduced, which is conducive to reducing the difficulty of welding between the convex portion and the first terminal portion, reducing the requirements for welding power, and improving the welding effect between the two.

[0022] In some embodiments, the first wall is provided with an electrode lead-out hole, which penetrates the first wall along the thickness direction of the first wall; the first terminal portion is provided on the side of the first wall facing away from the electrode assembly and covers the electrode lead-out hole, and at least part of the protrusion is accommodated in the electrode lead-out hole. The first terminal portion and the second terminal portion may both be located on the side of the first wall facing away from the electrode assembly, which can save the internal space of the housing, and is conducive to increasing the size of the electrode assembly within a limited space, thereby increasing the capacity of the battery cell.

[0023] In some embodiments, along the thickness direction of the first wall, a portion of the first pole lug is located between the first terminal portion and the first adapter, and is connected to the first adapter. The first adapter can support the first pole lug, which is beneficial to reduce the risk of the end of the first pole lug away from the main body being inserted into the main body, and can also reduce the bending degree of the first pole lug, reducing the risk of the first pole lug cracking due to stress concentration.

[0024] In some embodiments, the first wall is provided with an electrode lead-out hole, and the electrode lead-out hole penetrates the first wall along the thickness direction of the first wall; the first terminal portion includes a first terminal body, a first limiting portion, and a second limiting portion, the first limiting portion is at least partially arranged on the side of the first wall away from the electrode assembly, and the second limiting portion is at least partially arranged on the side of the first wall facing the electrode assembly, and at least a portion of the first terminal body is accommodated in the electrode lead-out hole and connects the first limiting portion and the second limiting portion; along the thickness direction of the first wall, a portion of the first pole ear is located between the second limiting portion and the first adapter. The gap between the second limiting portion and the first adapter is relatively small, and a portion of the first pole ear is more likely to contact the second limiting portion, thereby forming a flow path between the first pole ear and the second limiting portion.

[0025] In some embodiments, the portion of the first pole tab located between the second limit portion and the first adapter is connected to the second limit portion. A current flow path can be formed between the first pole tab and the first terminal portion, and part of the current can be directly transmitted between the first pole tab and the first terminal portion, which is beneficial to improving the current flow capacity of the battery cell.

[0026] In some embodiments, the first pole ear includes a folded section, a bent section, and an extended section. The folded section is located on the side of the first adapter facing the main body and connected to the main body. The bent section is located on the side of the first adapter along the width direction of the first wall. The bent section is connected between the folded section and the extended section. The extended section extends from the bent section to between the second limit portion and the first adapter. The extended section is welded to the first adapter and attached to the surface of the second limit portion facing the main body. The bent section and the first adapter can share at least part of the space in the thickness direction, which is beneficial to improve space utilization. In addition, the first pole ear only needs to be bent once, and there is no need to reserve a large bending space for the first pole ear between the first adapter and the main body, which is beneficial to improve the space utilization in the shell and improve the energy density of the battery cell.

[0027] In some embodiments, the first wall is provided with an electrode lead-out hole, and the electrode lead-out hole penetrates the first wall along the thickness direction of the first wall; the first terminal portion includes a first terminal body, a first limiting portion, and a second limiting portion, the first limiting portion is at least partially arranged on a side of the first wall away from the electrode assembly, and the second limiting portion is at least partially arranged on a side of the first wall facing the electrode assembly, and at least a portion of the first terminal body is accommodated in the electrode lead-out hole and connects the first limiting portion and the second limiting portion. At least a portion of the first limiting portion and at least a portion of the second limiting portion are respectively arranged on both sides of the first wall along the thickness direction, so that the first terminal portion can be limited in the thickness direction, reducing the risk of the first terminal portion falling into the inside or outside of the shell.

[0028] In some embodiments, the first electrode terminal is disposed on a side of the first wall away from the electrode assembly; the battery cell includes a fixing member, the fixing member is at least partially disposed on a side of the first electrode terminal away from the first wall, and the fixing member is connected to the first wall. The fixing member can apply a force toward the first wall to the first electrode terminal, which is conducive to pressing the first electrode terminal against the first wall, realizing the assembly of the first electrode terminal and the first wall, and can also improve the sealing performance of the battery cell.

[0029] In some embodiments, the fixing member includes a first fixing portion and a second fixing portion connected to each other, the first fixing portion is at least partially disposed on a side of the first electrode terminal away from the first wall, and the second fixing portion is fixed to the first wall; along the thickness direction of the first wall, a portion of the first terminal portion and / or a portion of the second terminal portion is located between the first fixing portion and the first wall. The first fixing portion can apply a force toward the first wall to the first terminal portion and / or the second terminal portion, thereby directly pressing the first terminal portion against the first wall, or indirectly pressing the first terminal portion against the first wall through the second terminal portion. The first fixing portion can also cause the second terminal portion to be pressed against the first terminal portion, which is beneficial to improving the connection strength and connection stability between the first terminal portion and the second terminal portion.

[0030] In some embodiments, the electrode assembly includes a second pole lug extending from the main body, the second pole lug has a polarity opposite to that of the first pole lug; the battery cell also includes a second electrode terminal and a second adapter, the second adapter connects the second pole lug and the second electrode terminal; the base metal of the second electrode terminal is the same as the base metal of the second terminal portion. The second terminal portion of one battery cell and the second electrode terminal of another battery cell can be welded to the same busbar, which is conducive to realizing the series connection between the two battery cells and reducing the difficulty of connection.

[0031] In some embodiments, the battery cell includes a busbar, at least part of which is located on a side of the second electrode terminal away from the main body; the busbar, the second adapter and the second electrode terminal are welded, and the base metal of the busbar, the base metal of the second adapter and the base metal of the second electrode terminal are the same. Thus, it is convenient to weld the busbar, the second adapter and the second electrode terminal together through a single welding process, which is conducive to simplifying the welding operation and improving the welding efficiency. In addition, the busbar can be directly electrically connected to the second adapter through the second welding portion, which is conducive to improving the current carrying capacity.

[0032] In some embodiments, the base metal of the first terminal portion and the base metal of the first adapter are both copper, and the base metal of the second terminal portion is aluminum. This facilitates welding between the first adapter and the first tab, welding between the first terminal portion and the first adapter, welding between the second terminal portion and the busbar, and welding between the busbar and the positive electrode of another battery cell.

[0033] In some embodiments, the first terminal portion and the second terminal portion are connected by at least one of cold rolling, hot rolling, explosive compounding, and explosive rolling, thereby improving the connection strength and stability between the first terminal portion and the second terminal portion and reducing the risk of the connection surfaces of the first terminal portion and the second terminal portion being separated from each other.

[0034] In some embodiments, the housing includes a shell and an end cap, the shell has an opening, the end cap is connected to the shell and covers the opening; the first wall is the end cap. During assembly, the electrode assembly and the first adapter can be installed in the shell through the opening, and then the end cap is covered on the opening, and then the first adapter and the first terminal are welded, which is conducive to simplifying the assembly operation and reducing the difficulty of assembly.

[0035] According to the second aspect of the present application, an embodiment of the present application provides a battery device, the battery device comprising a battery cell and a busbar component provided according to some embodiments of the first aspect of the present application. The base metal of the busbar component is the same as the base metal of the second terminal portion, and the busbar component is welded to the second terminal portion. Thus, it is helpful to simplify the welding operation of the busbar component and the second terminal portion, and improve the welding efficiency and welding effect.

[0036] In some embodiments, the electrode assembly includes a second pole lug extending from the main body, the second pole lug has a polarity opposite to that of the first pole lug; the battery cell also includes a second electrode terminal, the second electrode terminal is electrically connected to the second pole lug, the base metal of the second electrode terminal, the base metal of the second terminal portion, and the metal base of the busbar are the same; there are multiple battery cells; the busbar is welded to at least the second terminal portion of one battery cell and the second electrode terminal of another battery cell. The second terminal portion of one battery cell and the second electrode terminal of another battery cell can be welded to the same busbar, which is conducive to realizing the series connection between the two battery cells and reducing the difficulty of connection.

[0037] According to a second aspect of the present application, embodiments of the present application provide a battery device, the battery device comprising a battery cell provided according to some embodiments of the first aspect of the present application.

[0038] According to a third aspect of the present application, the present application provides an electrical device, which includes a battery device provided according to any embodiment of the second aspect of the present application, and the battery device is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 It is a schematic diagram of the structure of a vehicle provided in some embodiments of the present application.

[0041] Figure 2 It is a schematic diagram of the exploded structure of a battery device provided in some embodiments of the present application.

[0042] Figure 3 It is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application.

[0043] Figure 4 yes Figure 3 A schematic cross-sectional view of a battery cell is shown.

[0044] Figure 5 yes Figure 4 Schematic diagram of the enlarged structure of area A in the middle.

[0045] Figure 6 It is a partial structural cross-sectional view of a battery cell provided in some other embodiments of the present application.

[0046] Figure 7 is along Figure 4 Schematic cross-sectional view taken along direction BB.

[0047] Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of area C in the middle.

[0048] Fig. 9 It is a schematic diagram of the structure of the electrode assembly of the battery cell provided in some embodiments of the present application.

[0049] Fig.10 yes Fig. 9 Schematic diagram of the enlarged structure of area D in the middle.

[0050] Fig.11 It is a partial structural cross-sectional view of a battery cell provided in some other embodiments of the present application.

[0051] Fig.12 yes Fig.11 Schematic diagram of the enlarged structure of area E in the middle.

[0052] Fig.13 yes Figure 4 Schematic diagram of the enlarged structure of area F in the middle.

[0053] Fig.14 It is a partial structural cross-sectional view of a battery cell provided in some further embodiments of the present application.

[0054] Fig.15 It is a partial structural schematic diagram of a battery device provided in some embodiments of the present application.

[0055] In the attached figure: Vehicle 1, battery device 2, controller 3, motor 4; Box body 5, first box body part 5a, second box body part 5b, accommodating space 5c; Battery cell 6, electrode assembly 10, main body 11, first pole ear 12, folded section 121, bent section 122, extended section 123, second pole ear 13, shell 20, shell 21, opening 211, first wall 213, end cover 22, first wall 23, electrode lead-out hole 231, first electrode terminal 30, first terminal portion 31, first recess 311, bottom surface 311a, second wall 312, second recess 313, first terminal body 314, first limit portion 315, second limit portion Part 316, second terminal part 32, first through hole 321, hole wall 321a, second terminal body 322, step portion 323, step surface 323a, first adapter 40, adapter body 41, convex portion 42, top surface 42a, third recess 43, fixing member 51, first fixing portion 511, second fixing portion 512, insulating member 52, second electrode terminal 60, second adapter 70, busbar component 80, first welding portion W1, second welding portion W2, thickness direction X, width direction Y. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0058] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0059] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0060] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0061] In the embodiments of the present application, the same reference numerals represent 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 the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0062] The term “plurality” used in this application refers to two or more (including two).

[0063] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0064] In the embodiment of the present application, the battery cell may be a secondary battery cell, which refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0065] The battery cells can be lithium-ion battery cells, sodium-ion battery cells, sodium-lithium-ion battery cells, lithium metal battery cells, sodium metal battery cells, lithium-sulfur battery cells, magnesium-ion battery cells, nickel-hydrogen battery cells, nickel-cadmium battery cells, lead-acid battery cells, etc., which are not limited in the embodiments of the present application.

[0066] A battery cell generally includes an electrode assembly, a housing, and an electrode terminal. The electrode assembly is contained in the housing, and the electrode terminal is disposed in the housing. The housing is used to encapsulate the electrode assembly and components such as the electrolyte. The electrode assembly includes a tab, which is electrically connected to the electrode terminal through an adapter or directly electrically connected to the electrode terminal. The electrode terminal can be used to electrically connect the electrode assembly to a circuit outside the battery cell to realize charging or discharging of the battery cell.

[0067] The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and released back and forth between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive and negative electrodes from short-circuiting, while allowing active ions to pass through.

[0068] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet 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.

[0069] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet 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.

[0070] In some embodiments, a separator is disposed between the positive electrode and the negative electrode.

[0071] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical stability and mechanical stability can be selected.

[0072] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transmit ions and isolate the positive and negative electrodes.

[0073] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into a wound structure.

[0074] In some embodiments, the electrode assembly is a laminate structure.

[0075] The battery device mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, in parallel or in mixed connection through a busbar.

[0076] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0077] A battery device generally includes a case for encapsulating one or more battery cells, which can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0078] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by cable ties. The battery cell assembly may be accommodated in the box by fixing the battery module in the box. As an example, the box may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box to accommodate the battery cell assembly.

[0079] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0080] In some embodiments, the battery device may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[0081] The electrode assembly usually includes a main body and a tab extending from the main body, and the tab is usually connected to the electrode terminal through an adapter. In the related art, the tab can be welded to the adapter first, and the adapter is welded to the electrode terminal from one side of the adapter, and then the adapter, the electrode terminal and the electrode assembly are installed into the shell. However, welding particles generated during the welding process may remain on the adapter and then enter the interior of the shell, which may cause a short circuit inside the battery cell, thereby affecting the reliability of the battery cell.

[0082] In view of this, an embodiment of the present application provides a technical solution, which forms a first welding portion by abutting and welding at least a portion of the first adapter with the first terminal portion of the first electrode terminal, and making a portion of the first welding portion exposed on the outside of the first electrode terminal away from the electrode assembly. The electrode assembly and the first adapter can be first installed to the outer shell, and then the abutting portion of the first terminal portion and the first adapter can be heated from the outside of the first electrode terminal by laser or other means, so as to perform penetration welding on the first terminal portion and the first adapter. The possibility of welding particles generated during the welding process falling into the inner side of the first adapter facing the electrode assembly can be reduced, thereby reducing the risk of internal short circuit in the battery cell, which is beneficial to improving the reliability of the battery cell.

[0083] The technical solution provided in the embodiments of the present application is applicable to battery cells, battery devices, and electrical equipment using the battery devices.

[0084] The battery device disclosed in the embodiments of the present application can be used in various energy storage systems that use the battery device as a power source or use the battery device as an energy storage element. The electrical device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can include a fixed or mobile electric toy, for example, a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like, and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0085] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0086] Figure 1 is a schematic diagram of the structure of a vehicle provided by some embodiments of the present application. Figure 1The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery device 2 is provided inside the vehicle 1, and the battery device 2 may be provided at the bottom, head or tail of the vehicle 1. The battery device 2 may be used to power the vehicle 1, for example, the battery device 2 may be used as an operating power source for the vehicle 1. The vehicle 1 may also include a controller 3 and a motor 4, and the controller 3 is used to control the battery device 2 to power the motor 4, for example, for starting, navigating and driving the vehicle 1.

[0087] In some embodiments of the present application, the battery device 2 can not only serve as an operating power source for the vehicle 1, but also serve as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0088] Figure 2 is a schematic diagram of the exploded structure of a battery device provided in some embodiments of the present application. Figure 2 The battery device 2 includes a box body 5 and a battery cell 6, and the battery cell 6 is accommodated in the box body 5. The box body 5 is used to provide a storage space for the battery cell 6, and the box body 5 can adopt a variety of structures. In some embodiments, the box body 5 may include a first box body part 5a and a second box body part 5b, the first box body part 5a and the second box body part 5b cover each other, and the first box body part 5a and the second box body part 5b jointly define a storage space 5c for accommodating the battery cell 6. The second box body part 5b may be a hollow structure with one end open, the first box body part 5a may be a plate-shaped structure, the first box body part 5a covers the open side of the second box body part 5b, so that the first box body part 5a and the second box body part 5b jointly define the storage space 5c; the first box body part 5a and the second box body part 5b may also be hollow structures with one side open, and the open side of the first box body part 5a covers the open side of the second box body part 5b. Of course, the box body 5 formed by the first box body part 5a and the second box body part 5b can be in various shapes, such as a cylinder, a cuboid, etc.

[0089] In order to improve the sealing performance after the first box body part 5a and the second box body part 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body part 5a and the second box body part 5b.

[0090] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box.

[0091] In the battery device 2, there can be multiple battery cells 6, and the multiple battery cells 6 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 6 are both connected in series and in parallel. The multiple battery cells 6 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by the multiple battery cells 6 is accommodated in the box 5; of course, the battery device 2 can also be a battery module formed by connecting multiple battery cells 6 in series, in parallel, or in mixed connection, and then the multiple battery modules are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 5. The battery device 2 can also include other structures, for example, the battery device 2 can also include a busbar component for realizing electrical connection between the multiple battery cells 6.

[0092] For example, the battery cell 6 may be the smallest unit constituting the battery device 2 .

[0093] Figure 3 Schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application. Figure 3 The battery cell 6 includes an electrode assembly 10 and a shell 20 , and the electrode assembly 10 is disposed in the shell 20 .

[0094] The housing 20 is used to encapsulate the electrode assembly 10 and the electrolyte and other components. The housing 20 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing) or an aluminum-plastic film.

[0095] In some embodiments, the housing 20 is a hollow structure, and a space for accommodating the electrode assembly 10 and the electrolyte is formed therein. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a rectangular parallelepiped structure, a rectangular housing can be selected.

[0096] The material of the housing 20 can be various, for example, the material of the housing 20 can be metal or plastic. Optionally, the material of the housing 20 can be copper, iron, aluminum, steel, aluminum alloy, etc. Exemplarily, the housing 20 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell) or an aluminum-plastic film, etc.

[0097] As an example, the housing 20 includes a shell 21 and an end cover 22 . The shell 21 has an opening 211 , and the end cover 22 is used to cover the opening 211 .

[0098] The housing 21 is a component used to cooperate with the end cover 22 to form an internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0099] The housing 21 and the end cap 22 may be independent components. For example, an opening 211 may be provided on the housing 21 , and the end cap 22 may cover the opening 211 at the opening 211 to form an internal cavity of the battery cell 6 .

[0100] The shape of the end cap 22 can be adapted to the shape of the housing 21 to match the housing 21. The material of the end cap 22 can be the same as or different from that of the housing 21.

[0101] The end cover 22 can be connected to the housing 21 by welding, bonding, clamping or other methods.

[0102] The shell 21 may have an opening 211 at one end or at both ends. Exemplarily, the shell 21 has an opening 211 at one end, and one end cap 22 is provided to cover the opening 211 of the shell 21. As another example, the shell 21 may also have an opening 211 at both ends, and two end caps 22 are provided, and the two end caps 22 cover the two openings 211 of the shell 21, respectively.

[0103] Figure 4 yes Figure 3 A schematic cross-sectional view of a battery cell is shown, Figure 5 yes Figure 4 Schematic diagram of the enlarged structure of area A in the middle. Figure 6 is a partial structural cross-sectional view of a battery cell provided in some other embodiments of the present application, Figure 7 is along Figure 4 A cross-sectional view taken along the direction BB in FIG. Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of area C in the middle. Fig. 9 is a schematic diagram of the structure of an electrode assembly of a battery cell provided in some embodiments of the present application, Fig.10 yes Fig. 9 Schematic diagram of the enlarged structure of area D in the middle. Fig.11 is a partial structural cross-sectional view of a battery cell provided in some embodiments of the present application, Fig.12 yes Fig.11 Schematic diagram of the enlarged structure of area E in the middle. Fig.13 yes Figure 4 Schematic diagram of the enlarged structure of the middle area F, Fig.14 It is a partial structural cross-sectional view of a battery cell provided in some further embodiments of the present application.

[0104] Reference Figures 3 to 14, an embodiment of the present application provides a battery cell 6, the battery cell 6 includes an electrode assembly 10, a shell 20, a first electrode terminal 30 and a first adapter 40. The shell 20 includes a first wall 23. The electrode assembly 10 is accommodated in the shell 20, and the electrode assembly 10 includes a main body 11 and a first electrode tab 12 led out from the main body 11. The first electrode terminal 30 is arranged on the first wall 23, and the first electrode terminal 30 includes a first terminal portion 31 and a second terminal portion 32 connected to each other, and the base metal of the first terminal portion 31 and the base metal of the second terminal portion 32 are different. In the thickness direction X of the first wall 23, at least a part of the second terminal portion 32 is located on the side of the first terminal portion 31 away from the electrode assembly 10 and is used to connect with the busbar component. The first adapter 40 connects the first electrode tab 12 and the first terminal portion 31. The base metal of the first adapter 40 is the same as the base metal of the first terminal portion 31. In the thickness direction X of the first wall 23, the first adapter 40 is at least partially located on the side of the first terminal portion 31 facing the main body portion 11. At least a portion of the first adapter 40 abuts against and is welded to the first terminal portion 31 to form a first welding portion W1. A portion of the first welding portion W1 is exposed on the side of the first electrode terminal 30 away from the electrode assembly 10 along the thickness direction X. A first recess 311 is provided on the side of the first terminal portion 31 facing the main body portion 11, and a portion of the first welding portion W1 is provided on the bottom wall of the first recess 311.

[0105] The first wall 23 may be the end cover 22, or may be one of the shell walls of the shell 21. Figure 3 and Figure 4 In the illustrated embodiment, the first wall 23 is an end cap 22 .

[0106] The main body 11 is the core part of the electrode assembly 10 to realize the charging and discharging functions. The first electrode tab 12 can be led out from one end of the main body 11 close to the first wall 23, or from other ends of the main body 11. Figure 3 In the illustrated embodiment, the first electrode tab 12 is led out from one end of the main body 11 close to the first wall 23 , which is helpful to simplify the structure of the first adapter 40 .

[0107] The first electrode tab 12 can be connected to the first adapter 40 by welding, abutment or other suitable methods.

[0108] In the embodiment of the present application, “base metal” refers to the main metal component. The main metal component of the first terminal portion 31 is different from the main metal component of the second terminal portion 32, and the main metal component of the first adapter 40 is the same as the main metal component of the first terminal portion 31, so as to facilitate welding of the first adapter 40 and the first terminal portion 31.

[0109] Optionally, the first electrode tab 12 is a negative electrode tab. The first terminal portion 31 and the first adapter 40 may be made of copper or copper alloy, and the base metals of the first terminal portion 31 and the first adapter 40 are both copper. The second terminal portion 32 may be made of aluminum or aluminum alloy, and the base metal of the second terminal portion 32 is aluminum.

[0110] In the thickness direction X of the first wall 23, the second terminal portion 32 may be located as a whole on the side of the first terminal portion 31 away from the electrode assembly 10, or only a part of the second terminal portion 32 may be located on the side of the first terminal portion 31 away from the electrode assembly 10, and the other part of the second terminal portion 32 may, for example, be wrapped around the outer periphery of the first terminal portion 31.

[0111] The second terminal portion 32 is used to connect to the busbar component. The second terminal portion 32 can be connected to the busbar component by welding, bonding or other appropriate methods.

[0112] Optionally, the base metal of the second terminal portion 32 may be the same as the base metal of the busbar component, so that the two can be connected by welding, which is beneficial to improving the connection strength and connection stability.

[0113] The first adapter 40 may be in contact with the first terminal portion 31 in its entirety along the thickness direction X, or only a portion of the first adapter 40 may be in contact with the first terminal portion 31 in the thickness direction X. The portion of the first adapter 40 that contacts the first terminal portion 31 is welded to the first terminal portion 31, and a small gap is provided between the portion and the first terminal portion 31, which is beneficial to reducing the risk of cold welding and improving the welding effect.

[0114] The first adapter 40 and the first terminal portion 31 can be welded by penetration welding. Specifically, the first terminal portion 31 and the first adapter 40 can be heated by laser or other means, so that the contacting parts of the first terminal portion 31 and the first adapter 40 melt and fuse together, and the fused parts solidify to form the first welding portion W1.

[0115] The side of the first electrode terminal 30 away from the electrode assembly 10 along the thickness direction X is the outside of the first electrode terminal 30 facing away from the inside of the housing 20. The part of the first welding portion W1 exposed on the side of the first electrode terminal 30 away from the electrode assembly 10 along the thickness direction X means that a part of the first welding portion W1 can be exposed from the outside of the first electrode terminal 30. In other words, the welding surface of the first terminal portion 31 for directly receiving welding heat is located on the side of the first terminal portion 31 facing away from the main body 11, and the welding surface of the first terminal portion 31 is exposed from the outside of the first electrode terminal 30 to directly receive welding heat (for example, receiving irradiated laser). When performing the welding operation, the first terminal portion 31 and the first adapter 40 can be heated from the outside of the first electrode terminal 30, so that a part of the first welding portion W1 is exposed from the outside of the first electrode terminal 30.

[0116] The orthographic projection of the second terminal portion 32 and the orthographic projection of the first welding portion W1 do not overlap in the same plane perpendicular to the thickness direction X. In other words, the second terminal portion 32 does not cover the first welding portion W1 along the thickness direction X, so that a portion of the first welding portion W1 is exposed on the side of the second terminal portion 32 away from the electrode assembly 10 along the thickness direction X.

[0117] Optionally, the second terminal portion 32 may be provided with a through hole, a through groove or other structure that passes through the second terminal portion 32 along the thickness direction X, and the first welding portion W1 may be exposed on the side of the first electrode terminal 30 away from the electrode assembly 10 along the thickness direction X through the through hole, through groove or other structure of the second terminal portion 32.

[0118] The first adapter 40 can be welded to the bottom wall of the first recess 311 to form a first welding portion W1, a portion of the first welding portion W1 is directly connected to the first adapter 40, and another portion of the first welding portion W1 is directly connected to the bottom wall of the first recess 311, and at least the portion of the first welding portion W1 directly connected to the first terminal portion 31 can be exposed on the outside of the first electrode terminal 30.

[0119] Optionally, a portion of the first welding portion W1 may protrude from a surface of the first terminal portion 31 facing away from the electrode assembly 10 along the thickness direction X, and the portion may be exposed outside the first electrode terminal 30 .

[0120] During assembly, the first pole tab 12 may be connected to the first adapter 40 and the first pole tab 12 may be bent; then the electrode assembly 10 and the first adapter 40 may be installed as a whole on the housing 21; then the first wall 23 may be assembled to the housing 21, and finally the first adapter 40 and the first terminal portion 31 may be welded. Specifically, the abutting portion of the first terminal portion 31 and the first adapter 40 may be heated from the outside of the first electrode terminal 30 by laser or other means, so that the first terminal portion 31 and the first adapter 40 are penetrated and welded, which may reduce the possibility of welding particles generated during welding falling into the side of the first adapter 40 facing the electrode assembly 10, reduce the risk of internal short circuit of the battery cell 6, and help improve the reliability of the battery cell 6.

[0121] Furthermore, the first pole lug 12 and the first adapter 40 are first inserted into the shell, and then the first adapter 40 and the first terminal portion 31 are welded. On the one hand, the length of the first pole lug 12 led out from the main body 11 can be shortened, saving the space required for bending the first pole lug 12, which is beneficial to improving the energy density of the battery cell 6; on the other hand, the first pole lug 12 and the first adapter 40 are in a natural state, which can reduce external force pulling and reduce the risk of cracking of the first pole lug 12.

[0122] The first recess 311 is located on the side of the first terminal portion 31 facing the main body portion 11, and a portion of the first terminal portion 31 can be thinned from the side of the first terminal portion 31 facing the main body portion 11 to form the first recess 311. On the one hand, the bottom wall of the first recess 311 is closer to the side of the first wall 23 facing away from the main body portion 11 in the thickness direction X, which can shorten the distance between the welding device and the bottom wall of the first recess 311, which is conducive to reducing the difficulty of welding, reducing the diffusion of welding heat, and reducing the adverse effects on other components.

[0123] In some embodiments, the battery cell 6 further includes an insulating support member, which is disposed on the main body 11 and is located between the main body 11 and the first adapter 40. The insulating support member can be used to support the first adapter 40 so that a portion of the first adapter 40 abuts against the first terminal portion 31, which is beneficial to improving the welding effect of the first adapter 40 and the first terminal portion 31.

[0124] Optionally, the insulating support member may be an insulating film, an insulating bracket or other components that can perform insulating and supporting functions.

[0125] In some embodiments, the first terminal portion 31 and the second terminal portion 32 are stacked along the thickness direction X of the first wall 23 , and the second terminal portion 32 is located on a side of the first wall 23 away from the main body 11 along the thickness direction X of the first wall 23 .

[0126] Along the thickness direction X, the second terminal portion 32 is located as a whole on the side of the first terminal portion 31 and the first wall 23 away from the electrode assembly 10. In the thickness direction X, there is no thickness overlap between the second terminal portion 32 and the first wall 23, which can increase the distance between the surface of the second terminal portion 32 facing away from the first wall 23 and the first wall 23. After the second terminal portion 32 is connected to the busbar component, the second terminal portion 32 can prop up the busbar component to a certain height along the thickness direction X to increase the distance between the busbar component and the first wall 23, which is conducive to reducing the risk of overlapping the busbar component and the first wall 23.

[0127] In some embodiments, reference Figures 5 and 6 The second terminal portion 32 is provided with a first through hole 321 , and the first through hole 321 penetrates the second terminal portion 32 along the thickness direction X of the first wall 23 .

[0128] In the same plane perpendicular to the thickness direction X of the first wall 23 , the orthographic projection of the first welding portion W1 is at least partially located within the orthographic projection of the first through hole 321 .

[0129] The second terminal portion 32 may be an annular structure surrounding the first through hole 321. Optionally, the orthographic projection of the first through hole 321 may be circular, rectangular or other shapes in a projection plane perpendicular to the thickness direction X. The outer contour of the second terminal portion 32 may be circular, rectangular or other shapes.

[0130] Optionally, in the same plane perpendicular to the thickness direction X of the first wall 23, the orthographic projection of the first through hole 321 and the orthographic projection of the first terminal portion 31 partially overlap, so that a portion of the first terminal portion 31 is exposed through the first through hole 321 to the side of the second terminal portion 32 facing away from the electrode assembly 10, which is beneficial to increase the area of ​​the first terminal portion 31 used for welding with the first adapter 40, reduce the difficulty of welding, and improve welding efficiency.

[0131] In the same plane perpendicular to the thickness direction X of the first wall 23, the orthographic projection of the first welding portion W1 may be entirely located within the orthographic projection of the first through hole 321, or only a portion of the orthographic projection of the first welding portion W1 may be located within the orthographic projection of the first through hole 321, and another portion of the orthographic projection of the first welding portion W1 may be located, for example, at the periphery of the orthographic projection of the first through hole 321.

[0132] The first through hole 321 can provide an escape space for the welding operation between the first terminal portion 31 and the first adapter 40, which is conducive to reducing the influence of the second terminal portion 32 on the welding operation, and on the other hand, it can also reduce the thickness of the welding area of ​​the first electrode terminal 30 used for welding the first adapter 40, which is conducive to reducing the welding power and reducing the welding heat. In addition, the first through hole 321 can also provide a certain indication and positioning function for the welding operation, which is conducive to limiting the range of the first terminal portion 31 that can be used for welding to the area with a relatively thin thickness, thereby improving the welding effect.

[0133] In some embodiments, reference Figure 5 and Figure 6 The first terminal portion 31 has a second wall 312 , and along the thickness direction X of the first wall 23 , the second wall 312 is located between the first through hole 321 and the first recess 311 . A portion of the first welding portion W1 is provided on the second wall 312 .

[0134] The first recess 311 may be recessed along the thickness direction X at a surface of the first terminal portion 31 facing the main body portion 11 .

[0135] In the same plane perpendicular to the thickness direction X, the orthographic projection of the second wall 312 is located within the orthographic projections of the first through hole 321 and the first recess 311. The second wall 312 is a portion of the first terminal portion 31 corresponding to both the first recess 311 and the first through hole 321 along the thickness direction X.

[0136] The second wall 312 may form at least a portion of the bottom wall of the first recess 311. In some examples, in the same plane perpendicular to the thickness direction X, the orthographic projection of the first through hole 321 is located within the orthographic projection of the first recess 311, the orthographic projection of the first recess 311 exceeds the range of the orthographic projection of the first through hole 321, the second wall 312 forms a portion of the bottom wall of the first recess 311, and another portion of the bottom wall of the first recess 311 may abut against the second terminal portion 32 along the thickness direction X. In other examples, in the same plane perpendicular to the thickness direction X, the orthographic projection of the first through hole 321 completely overlaps with the orthographic projection of the first recess 311, or the orthographic projection of the first recess 311 is located within the orthographic projection of the first through hole 321, the orthographic projection of the first through hole 321 exceeds the range of the orthographic projection of the first recess 311, and the second wall 312 forms the bottom wall of the first recess 311.

[0137] A portion of the first welding portion W1 is disposed on the second wall 312 and is directly connected to the second wall 312. Another portion of the first welding portion W1 may be disposed on the first adapter 40 and is directly connected to the first adapter 40.

[0138] Along the thickness direction X, the second wall 312 is arranged corresponding to at least a portion of the first recess 311. The thickness of the second wall 312 is relatively thin. The first adapter 40 is welded to the second wall 312, which is beneficial to reduce the welding difficulty, reduce the requirements for welding power, and improve the welding effect.

[0139] In some embodiments, in the same plane perpendicular to the thickness direction X of the first wall 23 , the orthographic projection of the first through hole 321 is located within the orthographic projection of the first recess 311 .

[0140] In the same plane perpendicular to the thickness direction X, the orthographic projection of the first through hole 321 may completely overlap with the orthographic projection of the first recess 311 , and the orthographic projection of the first recess 311 may also exceed the orthographic projection range of the first through hole 321 .

[0141] The orthographic projection of the first through hole 321 is located within the orthographic projection of the first recess 311. When the first terminal portion 31 and the first adapter 40 are welded through the first through hole 321, the possibility of the weld mark exceeding the bottom wall of the first recess 311 can be reduced. The first welding portion W1 is not easily formed in the thicker portion of the first terminal portion 31, which is beneficial to improving the welding effect.

[0142] In some embodiments, in the same plane perpendicular to the thickness direction X of the first wall 23, the orthographic projection area of ​​the first recess 311 is greater than the orthographic projection area of ​​the first through hole 321. In other words, the orthographic projection of the first recess 311 exceeds the orthographic projection range of the first through hole 321. A portion of the orthographic projection of the first recess 311 completely overlaps with the orthographic projection of the first through hole 321, and another portion of the orthographic projection of the first recess 311 is located outside the orthographic projection of the first through hole 321.

[0143] The orthographic projection area of ​​the first recess 311 is larger than the orthographic projection area of ​​the first through hole 321. When the first terminal portion 31 and the first adapter 40 are welded through the first through hole 321, even if part of the weld mark extends to the periphery of the second wall 312, this part of the weld mark is not easy to exceed the bottom wall of the first recess 311. The first welding portion W1 is not easy to be formed in the thicker part of the first terminal portion 31, which is beneficial to improve the welding effect and reduce the heat generated by welding.

[0144] In some embodiments, reference Figure 6 A second recess 313 is provided on the side of the first terminal portion 31 facing away from the electrode assembly 10. In the same plane perpendicular to the thickness direction X of the first wall 23, the orthographic projection of the first recess 311 and the orthographic projection of the second recess 313 at least partially overlap. Along the thickness direction X of the first wall 23, the second wall 312 is located between the first recess 311 and the second recess 313.

[0145] The second recess 313 is recessed in the surface of the first terminal portion 31 facing away from the electrode assembly 10. The first recess 311 and the second recess 313 are recessed in opposite directions.

[0146] In the same plane perpendicular to the thickness direction X, the orthographic projection of the first concave portion 311 and the orthographic projection of the second concave portion 313 may completely overlap or partially overlap.

[0147] The first wall 23 may be provided with an electrode lead-out hole 231, which penetrates the first wall 23 along the thickness direction X. At least a portion of the first terminal portion 31 is provided in the electrode lead-out hole 231. In the same plane perpendicular to the thickness direction X, the orthographic projection of the first recess 311 and the orthographic projection of the second recess 313 are both located within the orthographic projection of the electrode lead-out hole 231.

[0148] The second wall 312 is located between the first recess 311 and the second recess 313, which means that, in the same plane perpendicular to the thickness direction X, the orthographic projection of the second wall 312 is simultaneously located in the orthographic projections of the first recess 311, the second recess 313, and the first through hole 321. In other words, along the thickness direction X, the portion of the first terminal portion 31 corresponding to the first recess 311, the second recess 313, and the first through hole 321 forms the second wall 312.

[0149] The first adapter 40 is welded to the second wall 312 , a portion of the first welding portion W1 is disposed on the second wall 312 , and the second wall 312 is located between the first recess 311 and the second recess 313 , which can further reduce the thickness of the second wall 312 , thereby further improving the welding effect and reducing welding heat generation.

[0150] In some embodiments, in the same plane perpendicular to the thickness direction X of the first wall 23 , the orthographic projection of the second recess 313 is located within the orthographic projection of the first recess 311 .

[0151] In the same plane perpendicular to the thickness direction X, the orthographic projection of the second recess 313 may completely overlap with the orthographic projection of the first recess 311 , and the orthographic projection range of the first recess 311 may also exceed the orthographic projection range of the second recess 313 .

[0152] During the welding process of the first terminal portion 31 and the first adapter 40, the second recess 313 can have a certain indication effect on the welding area, and the orthographic projection of the second recess 313 is located within the orthographic projection of the first recess 311, which is conducive to reducing the possibility that the first welding portion W1 exceeds the second wall 312. In addition, the size of the second recess 313 is not too large, which is conducive to increasing the flow area of ​​the first terminal portion 31 and improving its flow capacity.

[0153] In some embodiments, at least a portion of the first adapter 40 is accommodated in the first recess 311 and abuts against a bottom surface 311 a of the first recess 311 . Along the thickness direction X of the first wall 23 , the size of the first recess 311 is larger than that of the second recess 313 .

[0154] Optionally, the first adapter 40 may include an adapter body 41 and a protrusion 42, the adapter body 41 is arranged on the side of the first wall 23 facing the main body 11 and is connected to the first pole ear 12, the protrusion 42 protrudes from the surface of the adapter body 41 facing the first wall 23, and at least a portion of the protrusion 42 is accommodated in the first recess 311 and abuts against the bottom surface 311a of the first recess 311.

[0155] Optionally, the protrusion 42 is welded to the second wall 312 to form a first welding portion W1 , a portion of the first welding portion W1 is provided on the protrusion 42 , and the first welding portion W1 connects the protrusion 42 and the second wall 312 .

[0156] The adapter body 41 can be connected to the first electrode tab 12 by welding or other suitable methods.

[0157] The first recess 311 may be used to accommodate at least a portion of the first adapter 40 , and the first recess 311 and the first adapter 40 may share at least a portion of the space in the thickness direction X.

[0158] In some embodiments, in the same plane perpendicular to the thickness direction X of the first wall 23 , the orthographic projection of the second recess 313 is located within the orthographic projection of the first through hole 321 .

[0159] In the same plane perpendicular to the thickness direction X, the orthographic projection of the second recess 313 may completely overlap with the orthographic projection of the first through hole 321 , and the orthographic projection range of the first through hole 321 may also exceed the orthographic projection range of the second recess 313 .

[0160] The orthographic projection of the second recess 313 is located within the orthographic projection of the first through hole 321, which can reduce the size of the second recess 313, increase the area of ​​the first terminal portion 31 for connecting with the second terminal portion 32, and reduce the possibility of the second terminal portion 32 being partially suspended, which is conducive to enhancing the connection strength between the first terminal portion 31 and the second terminal portion 32. In addition, the second recess 313 is located on the outside of the first terminal portion 31 facing the first through hole 321, so it is easy to obtain the position of the second recess 313 from the outside. Even if the size of the second recess 313 is relatively small, it is easy to determine the position of the welding area, reducing the possibility of the welding mark exceeding the second wall 312.

[0161] In some embodiments, in the same plane perpendicular to the thickness direction X of the first wall 23, the orthographic projection area of ​​the first through hole 321 is greater than the orthographic projection area of ​​the second recess 313. In other words, the orthographic projection range of the first through hole 321 may also exceed the orthographic projection range of the second recess 313. A portion of the orthographic projection of the first through hole 321 completely overlaps with the orthographic projection of the second recess 313, and another portion of the orthographic projection of the first through hole 321 is located outside the orthographic projection of the second recess 313.

[0162] The size of the second recess 313 is relatively small, which is conducive to increasing the flow area of ​​the first terminal portion 31 and improving its flow capacity. In addition, the boundary of the second recess 313 can be exposed, and the boundary of the second recess 313 can be used as a reference, which is more conducive to determining the position of the welding area and reducing the risk of welding misalignment.

[0163] In some embodiments, reference Figures 5 and 6 The first welding portion W1 is spaced apart from the hole wall 321 a of the first through hole 321 . The first welding portion W1 is not directly connected to the hole wall 321 a of the first through hole 321 .

[0164] Optionally, the first through hole 321 may be cylindrical, and in the radial direction of the first through hole 321 , the minimum distance between the first welding portion W1 and the hole wall 321 a of the first through hole 321 is greater than zero.

[0165] Alternatively, the first through hole 321 may be prism-shaped, and the hole wall 321a of the first through hole 321 includes a plurality of wall surfaces sequentially connected along the circumference of the first through hole 321, and the first welding portion W1 is spaced apart from any wall surface.

[0166] In the embodiment of the present application, the first welding portion W1 is spaced apart from the hole wall 321a of the first through hole 321, which not only facilitates the welding operation between the first terminal portion 31 and the first adapter 40, but also reduces the heat transferred to the second terminal portion 32 during the welding process, thereby reducing the risk of deformation of the second terminal portion 32.

[0167] In some embodiments, reference Figure 5 In the radial direction of the first through hole 321 , the minimum distance between the first welding portion W1 and the hole wall 321 a of the first through hole 321 is d, and 2 mm ≤ d ≤ 8 mm.

[0168] The first through hole 321 may be cylindrical. The minimum distance between the first welding portion W1 and the hole wall 321a refers to the distance between the position of the outer contour of the first welding portion W1 closest to the hole wall 321a and the hole wall 321a in the radial direction of the first through hole 321.

[0169] The outer contour of the first welding portion W1 may be roughly circular, rectangular or other regular shapes, or may be irregular shapes. The position closest to the hole wall 321a in the outer contour of the first welding portion W1 may be a line, or may be one or more points.

[0170] Optionally, d may be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm or any value therebetween.

[0171] In the embodiment of the present application, d is set to be greater than or equal to 2 mm, and the distance between the first welding portion W1 and the hole wall 321a is not too small, which is beneficial to reducing the heat transferred to the second terminal portion 32 during the welding process and reducing the risk of deformation of the second terminal portion 32; in the embodiment of the present application, d is set to be less than or equal to 8 mm, which is beneficial to increasing the size of the first welding portion W1 within a limited range and improving the welding strength between the first terminal portion 31 and the first adapter 40.

[0172] In some embodiments, reference Figure 5 and Figure 6 The first adapter 40 includes an adapter body 41 and a protrusion 42. The adapter body 41 is arranged on the side of the first wall 23 facing the main body 11 and is connected to the first pole ear 12. The protrusion 42 protrudes from the surface of the adapter body 41 facing the first wall 23 and abuts against the first terminal portion 31. The first welding portion W1 connects the protrusion 42 and the first terminal portion 31.

[0173] The first wall 23 may be provided with an electrode lead-out hole 231 , and the electrode lead-out hole 231 penetrates the first wall 23 along the thickness direction X. At least a portion of the protrusion 42 may be received in the electrode lead-out hole 231 .

[0174] The top surface of the convex portion 42 away from the adapter body 41 abuts against the first terminal portion 31. Optionally, the top surface of the convex portion 42 may abut against the bottom surface of the first concave portion 311.

[0175] The first welding portion W1 may be formed by welding the protrusion 42 and the first terminal portion 31 , a portion of the first welding portion W1 is directly connected to the protrusion 42 , and another portion of the first welding portion W1 is directly connected to the first terminal portion 31 .

[0176] Optionally, along the thickness direction X, the first welding portion W1 does not extend beyond the surface of the protrusion 42 facing the main body 11. In other words, the first welding portion W1 does not penetrate the protrusion 42 in the direction close to the main body 11, and the protrusion 42 is not welded through, which is beneficial to reduce the heat transferred to the electrode assembly 10 during the welding process and reduce the risk of damaging the electrode assembly 10 due to welding heat.

[0177] The convex portion 42 protrudes relative to the adapter body 41 in a direction away from the main body 11, and the welding area between the convex portion 42 and the first terminal portion 31 is closer to the outer side of the first wall 23 away from the main body 11, which is conducive to reducing the difficulty of the welding operation and improving the welding efficiency. In addition, the convex portion 42 can also enhance the overall strength of the first adapter 40 to a certain extent, reducing the risk of the first adapter 40 being deformed by heat during the welding process.

[0178] In some embodiments, the first adapter 40 is provided with a third recessed portion 43 facing the main body 11 at a position corresponding to the protruding portion 42 , and the third recessed portion 43 is recessed relative to a surface of the adapter body 41 facing the main body 11 .

[0179] Along the thickness direction X, the third recess 43 may be recessed in a direction away from the main body 11 on the surface of the adapter body 41 facing the main body 11. Along the thickness direction X, the third recess 43 and the protrusion 42 are disposed correspondingly.

[0180] The convex portion 42 may be a hollow structure, and the cavity inside the convex portion 42 forms the third concave portion 43 .

[0181] Optionally, the adapter body 41 may be a structure of uniform thickness, and the convex portion 42 may be a structure of uniform thickness. The thickness of the adapter body 41 and the thickness of the convex portion 42 may be the same or different.

[0182] Optionally, the first adapter 40 may be formed by stamping a plate-like member of equal thickness.

[0183] The embodiment of the present application can reduce the thickness of the top wall of the protrusion 42 by setting the third recess 43, which is beneficial to reduce the difficulty of welding between the protrusion 42 and the first terminal portion 31, reduce the requirements for welding power, improve the welding effect between the two, and reduce welding heat generation.

[0184] In some embodiments, at least a portion of the protrusion 42 is received in the first concave portion 311 . The top surface 42a of the protrusion 42 abuts against the bottom surface 311a of the first concave portion 311 , and the first welding portion W1 connects the top surface 42a of the protrusion 42 and the bottom surface 311a of the first concave portion 311 .

[0185] Optionally, along the thickness direction X, the size of the convex portion 42 may be larger than the size of the first concave portion 311, and only a portion of the convex portion 42 may be accommodated in the first concave portion 311, and the other portion of the convex portion 42 may extend out of the first concave portion 311 in a direction close to the main body portion 11. During assembly, the adapter body 41 and the first terminal portion 31 are unlikely to interfere with each other, which facilitates the top surface 42a of the convex portion 42 to abut against the bottom surface 311a of the first concave portion 311. Alternatively, the convex portion 42 may also be accommodated in the first concave portion 311 as a whole.

[0186] Optionally, the side wall of the protrusion 42 may be spaced apart from the side wall of the first recess 311 to facilitate installation of the protrusion 42 to the first recess 311 and facilitate the top surface 42a of the protrusion 42 to abut against the bottom surface 311a of the first recess 311 .

[0187] The top surface 42 a of the convex portion 42 is the surface of the convex portion 42 facing away from the main body 11 along the thickness direction X, and the bottom surface 311 a of the first concave portion 311 is the surface of the first concave portion 311 facing the main body 11 along the thickness direction X.

[0188] The first welding portion W1 may be formed by welding the top wall of the convex portion 42 and the bottom wall of the first concave portion 311. A portion of the first welding portion W1 is disposed on the top wall of the convex portion 42, and another portion of the first welding portion W1 is disposed on the bottom wall of the first concave portion 311.

[0189] The embodiment of the present application provides a first recess 311, and enables the first welding portion W1 to connect the top surface 42a of the protrusion 42 and the bottom surface 311a of the first recess 311, so that the thickness of the area of ​​the first terminal portion 31 used for welding with the protrusion 42 can be thinned, which is beneficial to reducing the difficulty of welding between the protrusion 42 and the first terminal portion 31, reducing the requirements for welding power, and improving the welding effect between the two.

[0190] In some embodiments, the first wall 23 is provided with an electrode lead-out hole 231, and the electrode lead-out hole 231 penetrates the first wall 23 along the thickness direction X of the first wall 23. The first terminal portion 31 is provided on a side of the first wall 23 facing away from the electrode assembly 10 and covers the electrode lead-out hole 231, and at least a portion of the protrusion 42 is accommodated in the electrode lead-out hole 231.

[0191] The second terminal portion 32 is at least partially located on the side of the first terminal portion 31 facing away from the main body portion 11. Therefore, the first terminal portion 31 and the second terminal portion 32 can both be located on the side of the first wall 23 facing away from the electrode assembly 10, which can save the internal space of the outer shell 20 and is beneficial to increasing the size of the electrode assembly 10 within a limited space, thereby increasing the capacity of the battery cell 6.

[0192] In some embodiments, reference Figures 7 to 10Along the thickness direction X of the first wall 23 , a portion of the first electrode tab 12 is located between the first terminal portion 31 and the first adapter 40 , and is connected to the first adapter 40 .

[0193] The first electrode tab 12 can be connected to the first adapter 40 by welding or other suitable methods.

[0194] The first electrode tab 12 may be connected to the first terminal portion 31, or may be spaced apart from the first terminal portion 31. Optionally, the first electrode tab 12 may directly contact the first terminal portion 31, thereby being electrically connected to the first terminal portion 31.

[0195] The first tab 12 may include a plurality of tab layers stacked together, which may be directly welded to the first adapter 40 , or pre-welded together by ultrasonic welding or other methods, and then connected to the first adapter 40 by laser welding or other methods.

[0196] The tab layer has a certain flexibility, and there is a certain gap between adjacent tab layers. In the process of welding the first adapter 40 to the first terminal portion 31, the portion of the first tab 12 located between the first adapter 40 and the first terminal portion 31 can be squeezed by the first adapter 40 and the first terminal portion 31 to compress the interlayer gap of this portion. Part of the tab layer can be in contact with the first terminal portion 31, so as to form a current flow path between the first tab 12 and the first terminal portion 31, which is beneficial to improve the current flow capacity of the battery cell 6. In addition, by compressing the interlayer gap of the first tab 12, part of the tab layer can be in contact with the first terminal portion 31, and the risk of a cold weld caused by a loose fit between the welding surface of the first adapter 40 and the first terminal portion 31 can be reduced.

[0197] A portion of the first pole ear 12 is located between the first terminal portion 31 and the first adapter 40, and is connected to the first adapter 40. The first adapter 40 can support the first pole ear 12, which is beneficial to reduce the risk of the end of the first pole ear 12 away from the main body portion 11 being inserted into the main body portion 11, and can also reduce the bending degree of the first pole ear 12, thereby reducing the risk of the first pole ear 12 cracking due to stress concentration.

[0198] In some embodiments, reference Figure 5 and Figure 8The first wall 23 is provided with an electrode lead-out hole 231, and the electrode lead-out hole 231 penetrates the first wall 23 along the thickness direction X of the first wall 23. The first terminal portion 31 includes a first terminal body 314, a first limit portion 315, and a second limit portion 316. The first limit portion 315 is at least partially disposed on a side of the first wall 23 away from the electrode assembly 10, and the second limit portion 316 is at least partially disposed on a side of the first wall 23 facing the electrode assembly 10. At least a portion of the first terminal body 314 is accommodated in the electrode lead-out hole 231 and connects the first limit portion 315 and the second limit portion 316. Along the thickness direction X of the first wall 23, a portion of the first electrode tab 12 is located between the second limit portion 316 and the first adapter 40.

[0199] The first terminal body 314 is inserted into the electrode lead-out hole 231, and a portion of the first terminal body 314 may extend out of the electrode lead-out hole 231 along the thickness direction X. The first stopper 315 may be connected to an end of the first terminal body 314 away from the main body 11 along the thickness direction X, and the second stopper 316 may be connected to an end of the first terminal body 314 close to the main body 11 along the thickness direction X.

[0200] Optionally, the first terminal body 314, the first limiting portion 315 and the second limiting portion 316 are an integrally formed structure. At least one of the first limiting portion 315 and the second limiting portion 316 can be formed by riveting.

[0201] The first terminal body 314 may be a hollow cylindrical structure or a solid columnar structure.

[0202] The first terminal body 314 has an outer circumferential surface surrounding the central axis thereof, and the first limiting portion 315 and the second limiting portion 316 can be connected to and protrude from the outer circumferential surface of the first terminal body 314 .

[0203] Optionally, at least a portion of the second position-limiting portion 316 may be located between the first wall 23 and the adapter body 41 along the thickness direction X. The second position-limiting portion 316 and the adapter body 41 may be spaced apart to reduce the possibility of interference between the second position-limiting portion 316 and the adapter body 41, which is beneficial for the convex portion 42 to abut against the bottom surface 311a of the first concave portion 311.

[0204] At least a portion of the first limiting portion 315 and at least a portion of the second limiting portion 316 are respectively arranged on both sides of the first wall 23 along the thickness direction X, so as to limit the first terminal portion 31 in the thickness direction X and reduce the risk of the first terminal portion 31 falling into or outside the housing 20.

[0205] At least a portion of the second limiting portion 316 is located on the side of the first wall 23 facing the main body 11, and the gap between the second limiting portion 316 and the first adapter 40 is relatively small. In the embodiment of the present application, a portion of the first pole ear 12 is disposed between the second limiting portion 316 and the first adapter 40, and a portion of the first pole ear 12 is more likely to contact the second limiting portion 316, thereby forming a current path between the first pole ear 12 and the second limiting portion 316.

[0206] In some embodiments, a portion of the first electrode tab 12 located between the second limiting portion 316 and the first adapter 40 is connected to the second limiting portion 316 .

[0207] The portion of the first pole lug 12 located between the second limiting portion 316 and the first adapter 40 can contact the second limiting portion 316, thereby being electrically connected to the second limiting portion 316. A current flow path can be formed between the first pole lug 12 and the first terminal portion 31, and part of the current can be directly transmitted between the first pole lug 12 and the first terminal portion 31, which is beneficial to improving the current flow capacity of the battery cell 6.

[0208] In some embodiments, reference Figure 8 and Fig.10 The first pole tab 12 includes a folded section 121, a bent section 122 and an extended section 123. The folded section 121 is located on the side of the first adapter 40 facing the main body 11 and connected to the main body 11. The bent section 122 is located on the side of the first adapter 40 along the width direction Y of the first wall 23. The bent section 122 is connected between the folded section 121 and the extended section 123. The extended section 123 extends from the bent section 122 to between the second limit portion 316 and the first adapter 40. The extended section 123 is welded to the first adapter 40 and attached to the surface of the second limit portion 316 facing the main body 11.

[0209] The gathered section 121 is a portion of the first tab 12 used for direct connection with the main body 11. The gathered section 121 may extend from one end of the main body 11 facing the first wall 213 to one side of the first adapter 40 along the width direction Y of the first wall 213.

[0210] The bending section 122 is bent relative to the gathering section 121 and the extending section 123. Optionally, the bending section 122 may be bent into an arc shape.

[0211] Along the thickness direction X, at least part of the extension section 123 may be sandwiched between the first adapter 40 and the second stopper 316. Optionally, at least part of the first adapter 40 is sandwiched between the adapter body 41 and the second stopper 316. The adapter body 41 may be an annular structure disposed around the outer periphery of the protrusion 42.

[0212] Optionally, the number of electrode assemblies 10 may be two, and the two electrode assemblies 10 are stacked along the width direction Y of the first wall 23. The first pole tabs 12 of the two electrode assemblies 10 are both connected to the first adapter 40. The bending sections 122 of the first pole tabs 12 of the two electrode assemblies 10 are respectively located on opposite sides of the first adapter 40 along the width direction Y, and the extension sections 123 of the first pole tabs 12 of the two electrode assemblies 10 extend toward each other along the width direction Y.

[0213] The extension section 123 can be welded to the first adapter 40 by laser welding or other suitable methods.

[0214] The extension section 123 is attached to the surface of the second limiting portion 316 facing the main body 11 , which can increase the contact area between the extension section 123 and the second limiting portion 316 , and further improve the flow capacity.

[0215] The folded section 121 and the extended section 123 of the first pole tab 12 are respectively located on both sides of the first adapter 40 along the thickness direction X, and the bent section 122 connected between the folded section 121 and the extended section 123 is located on one side of the first adapter 40 along the width direction Y. The bent section 122 and the first adapter 40 can share at least part of the space in the thickness direction X, which is beneficial to improve space utilization. In addition, the first pole tab 12 only needs to be bent once, and there is no need to reserve a large bending space for the first pole tab 12 between the first adapter 40 and the main body 11, which is beneficial to improve the space utilization in the housing 20 and improve the energy density of the battery cell 6.

[0216] In some embodiments, reference Figures 5 and 6 The first wall 23 is provided with an electrode lead-out hole 231, and the electrode lead-out hole 231 penetrates the first wall 23 along the thickness direction X of the first wall 23. The first terminal portion 31 includes a first terminal body 314, a first stopper 315, and a second stopper 316. The first stopper 315 is at least partially disposed on a side of the first wall 23 away from the electrode assembly 10, and the second stopper 316 is at least partially disposed on a side of the first wall 23 facing the electrode assembly 10. At least a portion of the first terminal body 314 is accommodated in the electrode lead-out hole 231 and connects the first stopper 315 and the second stopper 316.

[0217] At least a portion of the first limiting portion 315 and at least a portion of the second limiting portion 316 are respectively arranged on both sides of the first wall 23 along the thickness direction X, so as to limit the first terminal portion 31 in the thickness direction X and reduce the risk of the first terminal portion 31 falling into or outside the housing 20.

[0218] In some embodiments, reference Fig.11 and Fig.12The first electrode terminal 30 is disposed on a side of the first wall 23 away from the electrode assembly 10 . The battery cell 6 includes a fixing member 51 , a portion of which is disposed on a side of the first electrode terminal 30 away from the first wall 23 , and the fixing member 51 is connected to the first wall 23 .

[0219] The fixing member 51 may be an annular structure. For example, the fixing member 51 is a rotating body.

[0220] In some examples, a portion of the fixing member 51 may directly abut against the first electrode terminal 30 along the thickness direction X. The first wall 23 may be electrically connected to the first electrode terminal 30 through the fixing member 51, so that the first wall 23 is charged. In other examples, an insulating member may also be provided between a portion of the fixing member 51 and the first electrode terminal 30 along the thickness direction X, and a portion of the fixing member 51 may be indirectly pressed and fitted with the first electrode terminal 30 through the insulating member, and the fixing member 51 may be insulated and isolated from the first electrode terminal 30 through the insulating member.

[0221] In some examples, along the thickness direction X, a portion of the fixing member 51 may be disposed on a side of the first terminal portion 31 away from the first wall 23 and surround the second terminal portion 32. In other examples, along the thickness direction X, a portion of the fixing member 51 may be disposed on a side of the second terminal portion 32 away from at least a portion of the first wall 23.

[0222] Optionally, the fixing member 51 may be made of metal to improve the connection strength and stability between the fixing member 51 and the first wall 23 .

[0223] The fixing member 51 and the first wall 23 can be connected and relatively fixed by welding or other suitable means.

[0224] The first electrode terminal 30 is disposed on a side of the first wall 23 away from the electrode assembly 10 , and does not occupy the internal space of the housing 20 . The size of the electrode assembly 10 can be increased within a limited space, thereby increasing the capacity of the battery cell 6 .

[0225] In addition, a portion of the fixing member 51 is arranged on the side of the first electrode terminal 30 away from the first wall 23. The fixing member 51 can apply a force toward the first wall 23 to the first electrode terminal 30, which is beneficial for pressing the first electrode terminal 30 against the first wall 23, thereby realizing the assembly of the first electrode terminal 30 and the first wall 23, and can also improve the sealing performance of the battery cell 6.

[0226] In some embodiments, reference Fig.12The fixing member 51 includes a first fixing portion 511 and a second fixing portion 512 connected to each other, the first fixing portion 511 is at least partially disposed on a side of the first electrode terminal 30 away from the first wall 23, and the second fixing portion 512 is fixed to the first wall 23. Along the thickness direction X of the first wall 23, a portion of the first terminal portion 31 and / or a portion of the second terminal portion 32 is located between the first fixing portion 511 and the first wall 23.

[0227] The first fixing portion 511 may be disposed around at least a portion of the second terminal portion 32. The second fixing portion 512 may be bent or curved from the first fixing portion 511 toward the first wall 23. The second fixing portion 512 may be disposed along the outer periphery of the first electrode terminal 30, and a portion of the second fixing portion 512 may be attached to a surface of the first wall 23 that is away from the main body portion 11, so as to increase the connection area between the second fixing portion 512 and the first wall 23, and improve the connection strength and stability.

[0228] In some examples, only a portion of the first terminal portion 31 is located between the first fixing portion 511 and the first wall 23 , and at least a portion of the first fixing portion 511 is located on a side of the first terminal portion 31 away from the first wall 23 .

[0229] In some other examples, only a portion of the second terminal portion 32 is located between the first fixing portion 511 and the first wall 23 , and at least a portion of the first fixing portion 511 is located on a side of the second terminal portion 32 away from the first wall 23 .

[0230] In some other examples, a portion of the first terminal portion 31 and a portion of the second terminal portion 32 are both located between the first fixing portion 511 and the first wall 23 , and at least a portion of the first fixing portion 511 is located on a side of the second terminal portion 32 and the first terminal portion 31 away from the first wall 23 .

[0231] Optionally, the second terminal portion 32 has a second terminal body 322 and a step portion 323, and the step portion 323 protrudes from the outer peripheral surface of the second terminal body 322. Along the thickness direction X, at least part of the step portion 323 is located between the first terminal portion 31 and the first fixing portion 511. The step portion 323 has a step surface 323a facing away from the first terminal portion 31 along the thickness direction X, and the first fixing portion 511 can directly abut against the step surface 323a, or can be indirectly pressed and matched with the step surface 323a through other structures (such as an insulating member).

[0232] The first fixing portion 511 can apply a force toward the first wall 23 to the first terminal portion 31 and / or the second terminal portion 32, thereby directly pressing the first terminal portion 31 against the first wall 23, or indirectly pressing the first terminal portion 31 against the first wall 23 through the second terminal portion 32. When a portion of the second terminal portion 32 is located between the first fixing portion 511 and the first wall 23, or when a portion of the first terminal portion 31 and a portion of the second terminal portion 32 are both located between the first fixing portion 511 and the first wall 23, the first fixing portion 511 can also cause the second terminal portion 32 to be pressed against the first terminal portion 31, which is beneficial to improving the connection strength and connection stability between the first terminal portion 31 and the second terminal portion 32.

[0233] In some embodiments, reference Fig.11 and Fig.12 The battery cell 6 further includes an insulating member 52, which at least partially surrounds the first electrode terminal 30 and is fixed relative to the first electrode terminal 30. The first fixing portion 511 can be embedded in the insulating member 52. The second fixing portion 512 can be entirely disposed on the outer periphery of the insulating member 52, a portion of the second fixing portion 512 can also be embedded in the insulating member 52, and another portion of the second fixing portion 512 is connected to the first wall 23.

[0234] The insulating member 52 may be made of a high temperature resistant insulating material. Optionally, the insulating member 52 may be a plastic member. The insulating member 52 may be disposed on the outer periphery of the first electrode terminal 30 by integral injection molding.

[0235] The insulating member 52 can cover the first fixing portion 511 and a portion of the second fixing portion 512. On the one hand, it is beneficial to enhance the installation stability of the fixing member 51. On the other hand, it can also reduce the possibility of overlapping between the first fixing portion 511 and the first electrode terminal 30 or the busbar component, reduce the possibility of overlapping between the second fixing portion 512 and the first electrode terminal 30, and reduce the risk of short circuit.

[0236] In some embodiments, reference Figure 3 , Figure 4 , Fig.13 and Fig.14 The electrode assembly 10 includes a second pole tab 13 extending from the main body 11, and the second pole tab 13 has a polarity opposite to that of the first pole tab 12. The battery cell 6 also includes a second electrode terminal 60 and a second adapter 70, and the second adapter 70 connects the second pole tab 13 and the second electrode terminal 60. The base metal of the second electrode terminal 60 is the same as the base metal of the second terminal portion 32.

[0237] The first electrode tab 12 and the second electrode tab 13 may be led out from the same end of the main body 11 or from different ends of the main body 11. Optionally, the first electrode tab 12 and the second electrode tab 13 are both led out from the end of the main body 11 facing the first wall 23.

[0238] Optionally, the first electrode tab 12 is a negative electrode tab, and the second electrode tab 13 is a positive electrode tab. The second electrode terminal 60 and the second terminal portion 32 may be made of aluminum or aluminum alloy. The base metal of the second electrode terminal 60 and the base metal of the second terminal portion 32 may both be aluminum.

[0239] The second electrode terminal 60 is used to connect to the busbar component. The base metal of the second electrode terminal 60 is the same as the base metal of the second terminal portion 32. The second terminal portion 32 of one battery cell 6 and the second electrode terminal 60 of another battery cell 6 can be welded to the same busbar component, which is conducive to realizing the series connection between the two battery cells 6 and reducing the difficulty of connection.

[0240] In some embodiments, reference Fig.13 and Fig.14 The battery cell 6 includes a busbar component 80, at least part of which is located on a side of the second electrode terminal 60 away from the main body 11. The busbar component 80, the second adapter 70 and the second electrode terminal 60 are welded, and the base metal of the busbar component 80, the base metal of the second adapter 70 and the base metal of the second electrode terminal 60 are the same.

[0241] The busbar component 80, the second adapter 70 and the second electrode terminal 60 are welded to form a second welding portion W2. At least a portion of the second welding portion W2 is exposed on the side of the busbar component 80 that faces away from the second electrode terminal 60. Thus, the busbar component 80, the second adapter 70 and the second electrode terminal 60 can be welded from the side of the busbar component 80 that faces away from the first wall 23, which is conducive to reducing the possibility of welding particles falling into the interior of the housing 20 and reducing the risk of short circuit.

[0242] The busbar component 80 , the second adapter 70 , and the second electrode terminal 60 may be welded together by penetration welding, butt welding, or other suitable methods.

[0243] In some examples, reference Fig.13 Along the thickness direction X, at least a portion of the busbar component 80, at least a portion of the second electrode terminal 60, and at least a portion of the second adapter 70 are sequentially abutted and welded together by penetration welding.

[0244] In other examples, refer to Fig.14The current collecting component 80 and the second electrode terminal 60 respectively have a second through hole and a third through hole, and at least a portion of the second adapter 70 is accommodated in the second through hole and the third through hole and welded to the hole wall of the second through hole and the hole wall of the third through hole. In other words, a portion of the second welding portion W2 connects the second adapter 70 and the hole wall of the second through hole, and another portion of the second welding portion W2 connects the second adapter 70 and the hole wall of the third through hole.

[0245] Alternatively, the base metal of the busbar member 80 , the base metal of the second adapter 70 , and the base metal of the second electrode terminal 60 may all be aluminum.

[0246] In the embodiment of the present application, the busbar component 80 is pre-connected to the first electrode terminal 30 and the second adapter 70 . After the battery cells 6 are stacked, the busbar component 80 can be received and positioned, which is beneficial to simplifying the assembly process.

[0247] In the embodiment of the present application, the base metal of the current collecting component 80, the base metal of the second adapter 70 and the base metal of the second electrode terminal 60 are set to be the same, so that the current collecting component 80, the second adapter 70 and the second electrode terminal 60 can be welded together through a single welding process, which is conducive to simplifying the welding operation and improving the welding efficiency. In addition, the current collecting component 80 can be directly electrically connected to the second adapter 70 through the second welding portion W2, which is conducive to improving the current carrying capacity.

[0248] In some embodiments, the base metal of the first terminal portion 31 and the base metal of the first transition member 40 are both copper, and the base metal of the second terminal portion 32 is aluminum.

[0249] The first pole tab 12 is a negative pole tab, and the negative pole tab is made of copper. In the embodiment of the present application, the base metal of the first adapter 40 is set to copper, which is convenient for welding between the first adapter 40 and the first pole tab 12. In the embodiment of the present application, the base metal of the first terminal portion 31 is set to copper, which is convenient for welding between the first terminal portion 31 and the first adapter 40.

[0250] The second terminal portion 32 is used to connect to the busbar component, which is used to connect to the positive electrode of another battery cell 6. The positive electrode is usually made of aluminum. In the embodiment of the present application, the base metal of the second terminal portion 32 is set to aluminum, which is convenient for welding between the second terminal portion 32 and the busbar component, and also convenient for welding between the busbar component and the positive electrode of another battery cell 6.

[0251] In some embodiments, the first terminal portion 31 and the second terminal portion 32 are connected by at least one of cold rolling, hot rolling, explosive compounding, and explosive rolling. This helps to improve the connection strength and stability between the first terminal portion 31 and the second terminal portion 32 and reduce the risk of the connection surfaces of the first terminal portion 31 and the second terminal portion 32 being separated from each other.

[0252] In some embodiments, the housing 20 includes a shell 21 and an end cover 22. The shell 21 has an opening 211. The end cover 22 is connected to the shell 21 and covers the opening 211. The first wall 23 is the end cover 22.

[0253] The end cover 22 may be connected to the housing 21 by welding, clamping, bonding or other suitable methods.

[0254] The shell 21 and the end cover 22 are separate structures, and the first electrode terminal 30 is arranged on the end cover 22. During assembly, the electrode assembly 10 and the first adapter 40 can be installed in the shell 21 through the opening 211, and then the end cover 22 is covered on the opening 211, and then the first adapter 40 and the first terminal part 31 are welded, which is conducive to simplifying the assembly operation and reducing the difficulty of assembly.

[0255] According to the second aspect of the present application, the present application embodiment further provides a battery device 2, referring to Figure 2 and Fig.15 The battery device 2 includes a busbar component 80 and a battery cell 6 provided according to some embodiments of the first aspect of the present application. The battery cell 6 does not include the busbar component 80. The base metal of the busbar component 80 is the same as the base metal of the second terminal portion 32, and the busbar component 80 is welded to the second terminal portion 32.

[0256] Optionally, the first pole ear 12 is a negative pole ear, and the negative pole ear is made of copper. The first terminal portion 31 and the first adapter 40 can be made of copper or copper alloy, and the base metal of the first terminal portion 31 and the first adapter 40 is copper, which is convenient for welding. The second terminal portion 32 and the busbar component 80 can be made of aluminum or aluminum alloy, and the base metal of the second terminal portion 32 and the busbar component 80 is aluminum.

[0257] In the embodiment of the present application, the base metal of the busbar component 80 and the base metal of the second terminal portion 32 are set to be the same, which is beneficial to simplify the welding operation of the busbar component 80 and the second terminal portion 32 and improve the welding efficiency and welding effect.

[0258] In some embodiments, the electrode assembly 10 includes a second pole tab 13 extending from the main body 11, and the second pole tab 13 has a polarity opposite to that of the first pole tab 12. The battery cell 6 also includes a second electrode terminal 60, which is electrically connected to the second pole tab 13, and the base metal of the second electrode terminal 60, the base metal of the second terminal portion 32, and the metal base of the busbar 80 are the same. There are multiple battery cells 6, and the busbar 80 is welded to at least the second terminal portion 32 of one battery cell 6 and the second electrode terminal 60 of another battery cell 6.

[0259] The second electrode terminal 60 is connected to the busbar component 80. The base metal of the second electrode terminal 60, the base metal of the second terminal portion 32 and the metal base of the busbar component 80 are the same. The second terminal portion 32 of one battery cell 6 and the second electrode terminal 60 of another battery cell 6 can be welded to the same busbar component 80, which is conducive to realizing the series connection between the two battery cells 6 and reducing the difficulty of connection.

[0260] According to the second aspect of the present application, the present application embodiment further provides a battery device 2, referring to Figure 2 and Fig.15 The battery device 2 includes a battery cell 6 provided according to some embodiments of the first aspect of the present application. The battery cell 6 includes an electrode assembly 10, a housing 20, a first electrode terminal 30, a first adapter 40, a second electrode terminal 60, a second adapter 70 and a busbar component 80. The electrode assembly 10 includes a main body 11, and a first pole tab 12 and a second pole tab 13 extending from the main body 11. The first electrode terminal 30 and the second electrode terminal 60 are arranged on the first wall 23. The first electrode terminal 30 includes a first terminal portion 31 and a second terminal portion 32 connected to each other, and the base metal of the first terminal portion 31 and the base metal of the second terminal portion 32 are different. In the thickness direction X of the first wall 23, at least a portion of the second terminal portion 32 is located on a side of the first terminal portion 31 away from the electrode assembly 10 and is used to connect to the busbar component. The first adapter 40 connects the first electrode tab 12 and the first terminal portion 31. The base metal of the first adapter 40 is the same as the base metal of the first terminal portion 31. In the thickness direction X of the first wall 23, the first adapter 40 is at least partially located on the side of the first terminal portion 31 facing the main body 11. At least a portion of the first adapter 40 abuts against and is welded to the first terminal portion 31 to form a first welding portion W1. A portion of the first welding portion W1 is exposed on the side of the first electrode terminal 30 away from the electrode assembly 10 along the thickness direction X. A first recess 311 is provided on the side of the first terminal portion 31 facing the main body 11, and a portion of the first welding portion W1 is provided on the bottom wall of the first recess 311. The second adapter 70 connects the second electrode tab 13 and the second electrode terminal 60. The base metal of the second electrode terminal 60 is the same as the base metal of the second terminal portion 32. At least a portion of the current collector 80 is located on the side of the second electrode terminal 60 away from the main body 11. The busbar component 80 , the second adapter 70 , and the second electrode terminal 60 are welded, and the base metal of the busbar component 80 , the base metal of the second adapter 70 , and the base metal of the second electrode terminal 60 are the same.

[0261] In some embodiments, the battery device 2 includes a plurality of battery cells 6, and at least some of the battery cells 6 include an electrode assembly 10, a housing 20, a first electrode terminal 30, a first adapter 40, a second electrode terminal 60, a second adapter 70, and a busbar 80. The first adapter 40 connects the first pole tab 12 and the first terminal portion 31. The second adapter 70 connects the second pole tab 13 and the second electrode terminal 60. The busbar 80, the second adapter 70, and the second electrode terminal 60 are welded.

[0262] According to the third aspect of the present application, an embodiment of the present application further provides an electrical device, the electrical device comprising a battery device 2 provided according to any embodiment of the second aspect of the present application, the battery device 2 being used to provide electrical energy.

[0263] The battery cell 6 provided in the embodiment of the present application includes an electrode assembly 10, a shell 20, a first electrode terminal 30, a first adapter 40, a second electrode terminal 60, a second adapter 70 and a busbar 80. The shell 20 includes a shell 21 and an end cover 22. The electrode assembly 10 is accommodated in the shell 20, and the electrode assembly 10 includes a main body 11, and a first pole ear 12 and a second pole ear 13 led out from the main body 11. The first electrode terminal 30 and the second electrode terminal 60 are arranged on the end cover 22. The first electrode terminal 30 includes a first terminal portion 31 and a second terminal portion 32 connected to each other, and the base metal of the first terminal portion 31 and the base metal of the second terminal portion 32 are different. In the thickness direction X of the first wall 23, at least a portion of the second terminal portion 32 is located on the side of the first terminal portion 31 away from the electrode assembly 10 and is used to connect with the busbar. The first adapter 40 connects the first electrode tab 12 and the first terminal portion 31. The base metal of the first adapter 40 is the same as the base metal of the first terminal portion 31. In the thickness direction X of the first wall 23, the first adapter 40 is at least partially located on the side of the first terminal portion 31 facing the main body 11. At least a portion of the first adapter 40 abuts against the first terminal portion 31 and adopts external laser penetration welding to form a first welding portion W1. A portion of the first welding portion W1 is exposed on the side of the first electrode terminal 30 away from the electrode assembly 10 along the thickness direction X. A first recess 311 is provided on the side of the first terminal portion 31 facing the main body 11, and a portion of the first welding portion W1 is provided on the bottom wall of the first recess 311. The second electrode terminal 60, the second adapter 70 and the busbar 80 are welded by external laser penetration welding to form a second welding portion W2. A portion of the second welding portion W2 is exposed on the side of the busbar 80 facing away from the end cover 22. Along the thickness direction X of the first wall 23 , a portion of the first electrode tab 12 is located between the first terminal portion 31 and the first adapter 40 , and is connected to the first adapter 40 and the first terminal portion 31 .

[0264] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing including a first wall; An electrode assembly is contained in the housing, and includes a main body and a first electrode tab extending from the main body; a first electrode terminal, disposed on the first wall, the first electrode terminal comprising a first terminal portion and a second terminal portion connected to each other, a base metal of the first terminal portion and a base metal of the second terminal portion being different, and at least a portion of the second terminal portion being located on a side of the first terminal portion away from the electrode assembly in a thickness direction of the first wall and being used to connect to a busbar component; as well as a first adapter, connecting the first electrode tab and the first terminal portion, the base metal of the first adapter being the same as the base metal of the first terminal portion, the first adapter being at least partially located on a side of the first terminal portion facing the main body portion in the thickness direction, and being abutted against and welded to the first terminal portion to form a first welding portion, a portion of the first welding portion being exposed on a side of the first electrode terminal away from the electrode assembly along the thickness direction; A first recess is disposed on a side of the first terminal portion facing the main body portion, and a portion of the first welding portion is disposed on a bottom wall of the first recess.

2. The battery cell according to claim 1, characterized in that: The first terminal portion and the second terminal portion are stacked along the thickness direction, and the second terminal portion is located on a side of the first wall away from the main body portion along the thickness direction.

3. The battery cell according to claim 1, characterized in that: The second terminal portion is provided with a first through hole, and the first through hole penetrates the second terminal portion along the thickness direction of the first wall; In the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first welding portion is at least partially located within the orthographic projection of the first through hole.

4. The battery cell according to claim 3, characterized in that: In the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the first through hole is located within the orthographic projection of the first recess.

5. The battery cell according to claim 4, characterized in that: In the same plane perpendicular to the thickness direction of the first wall, an orthographic projection area of ​​the first recess is larger than an orthographic projection area of ​​the first through hole.

6. The battery cell according to claim 3, characterized in that: The first terminal portion has a second wall, and along the thickness direction of the first wall, the second wall is located between the first through hole and the first recess; A portion of the first welding portion is provided on the second wall.

7. The battery cell according to claim 6, characterized in that: A second recess is provided on a side of the first terminal portion facing away from the electrode assembly, and an orthographic projection of the first recess at least partially overlaps an orthographic projection of the second recess in a same plane perpendicular to the thickness direction of the first wall; The second wall is located between the first recessed portion and the second recessed portion along a thickness direction of the first wall.

8. The battery cell according to claim 7, characterized in that: In the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second recess is located inside the orthographic projection of the first recess.

9. The battery cell according to claim 7 or 8, characterized in that: In the same plane perpendicular to the thickness direction of the first wall, the orthographic projection of the second recess is located within the orthographic projection of the first through hole.

10. The battery cell according to claim 9, characterized in that: In the same plane perpendicular to the thickness direction of the first wall, an orthographic projection area of ​​the first through hole is larger than an orthographic projection area of ​​the second recess.

11. The battery cell according to claim 3, characterized in that: The first welding portion is spaced apart from a hole wall of the first through hole.

12. The battery cell according to claim 9, characterized in that: In the radial direction of the first through hole, the minimum distance between the first welding portion and the hole wall of the first through hole is d, and 2mm≤d≤8mm.

13. The battery cell according to claim 1, characterized in that: The first adapter includes an adapter body and a protrusion. The adapter body is arranged on the side of the first wall facing the main body and is connected to the first pole ear. The protrusion protrudes from the surface of the adapter body facing the first wall and abuts against the first terminal part. The first welding part connects the protrusion and the first terminal part.

14. The battery cell according to claim 13, characterized in that: The first adapter is provided with a third recessed portion facing the main body at a position corresponding to the protruding portion, and the third recessed portion is recessed relative to a surface of the adapter body facing the main body.

15. The battery cell according to claim 13 or 14, characterized in that: At least a portion of the convex portion is accommodated in the first concave portion, a top surface of the convex portion abuts against a bottom surface of the first concave portion, and the first welding portion connects the top surface of the convex portion and the bottom surface of the first concave portion.

16. The battery cell according to claim 13 or 14, characterized in that: The first wall is provided with an electrode lead-out hole, and the electrode lead-out hole penetrates the first wall along the thickness direction of the first wall; The first terminal portion is disposed on a side of the first wall facing away from the electrode assembly and covers the electrode lead-out hole, and at least a portion of the protrusion is accommodated in the electrode lead-out hole.

17. The battery cell according to claim 1, characterized in that: Along the thickness direction of the first wall, a portion of the first electrode tab is located between the first terminal portion and the first adapter, and is connected to the first adapter.

18. The battery cell according to claim 17, characterized in that: The first wall is provided with an electrode lead-out hole, and the electrode lead-out hole penetrates the first wall along the thickness direction of the first wall; The first terminal portion includes a first terminal body, a first limiting portion and a second limiting portion, wherein the first limiting portion is at least partially disposed on a side of the first wall away from the electrode assembly, and the second limiting portion is at least partially disposed on a side of the first wall facing the electrode assembly, and at least a portion of the first terminal body is accommodated in the electrode lead-out hole and connects the first limiting portion and the second limiting portion; Along the thickness direction of the first wall, a portion of the first electrode tab is located between the second limiting portion and the first adapter.

19. The battery cell according to claim 18, characterized in that: A portion of the first electrode tab located between the second limiting portion and the first adapter is connected to the second limiting portion.

20. The battery cell according to claim 19, characterized in that: The first pole ear comprises a folded section, a bent section and an extended section, the folded section is located on a side of the first adapter facing the main body and connected to the main body, the bent section is located on a side of the first adapter along the width direction of the first wall, the bent section is connected between the folded section and the extended section, and the extended section extends from the bent section to between the second limiting portion and the first adapter; The extension section is welded to the first adapter and is attached to a surface of the second limiting portion facing the main body.

21. The battery cell according to claim 1, characterized in that: The first wall is provided with an electrode lead-out hole, and the electrode lead-out hole penetrates the first wall along the thickness direction of the first wall; The first terminal portion includes a first terminal body, a first limiting portion and a second limiting portion, the first limiting portion is at least partially arranged on a side of the first wall away from the electrode assembly, the second limiting portion is at least partially arranged on a side of the first wall facing the electrode assembly, and at least a portion of the first terminal body is accommodated in the electrode lead-out hole and connects the first limiting portion and the second limiting portion.

22. The battery cell according to claim 1, characterized in that: The first electrode terminal is disposed on a side of the first wall away from the electrode assembly; The battery cell includes a fixing member, wherein the fixing member is at least partially disposed on a side of the first electrode terminal away from the first wall, and the fixing member is connected to the first wall.

23. The battery cell according to claim 22, characterized in that: The fixing member includes a first fixing portion and a second fixing portion connected to each other, the first fixing portion is at least partially disposed on a side of the first electrode terminal away from the first wall, and the second fixing portion is fixed to the first wall; Along the thickness direction of the first wall, a portion of the first terminal portion and / or a portion of the second terminal portion is located between the first fixing portion and the first wall.

24. The battery cell according to claim 1, characterized in that The electrode assembly includes a second electrode tab extending from the main body, wherein the second electrode tab has a polarity opposite to that of the first electrode tab; The battery cell further includes a second electrode terminal and a second adapter, wherein the second adapter connects the second electrode tab and the second electrode terminal; A base metal of the second electrode terminal is the same as a base metal of the second terminal portion.

25. The battery cell according to claim 24, characterized in that: The battery cell includes a busbar component, at least a portion of which is located on a side of the second electrode terminal away from the main body; The busbar component, the second adapter, and the second electrode terminal are welded, and the base metal of the busbar component, the base metal of the second adapter, and the base metal of the second electrode terminal are the same.

26. The battery cell according to claim 1, characterized in that: The base metal of the first terminal portion and the base metal of the first adapter are both copper; The base metal of the second terminal portion is aluminum.

27. The battery cell according to claim 1, characterized in that: The first terminal portion and the second terminal portion are connected by at least one of cold rolling, hot rolling, explosive compounding, and explosive rolling.

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

29. A battery device, characterized in that: include: A battery cell according to any one of claims 1 to 24, 26 to 28; as well as A busbar component, the base metal of the busbar component is the same as the base metal of the second terminal portion, and the busbar component is welded to the second terminal portion.

30. The battery device according to claim 29, characterized in that The electrode assembly includes a second electrode tab extending from the main body, wherein the second electrode tab has a polarity opposite to that of the first electrode tab; The battery cell further includes a second electrode terminal, the second electrode terminal is electrically connected to the second electrode tab, and the base metal of the second electrode terminal, the base metal of the second terminal portion and the metal base of the busbar component are the same; There are multiple battery cells; The busbar member is welded to at least the second terminal portion of one of the battery cells and the second electrode terminal of another of the battery cells.

31. A battery device, characterized in that: Comprising the battery cell according to claim 25.

32. An electrical equipment, characterized in that: Comprising a battery device according to any one of claims 29-31, the battery device is used to provide electrical energy.

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