Battery cell, battery device, and electric device

Abstract

The utility model relates to battery technology field discloses a kind of battery monomer, battery device and electric device, battery monomer includes: shell assembly is equipped with containing cavity and first shell wall, and first shell wall is equipped with mounting hole;Electrode assembly is equipped in containing cavity, and it includes tab group and active material coating part;Tab group includes welding portion and gathers part, and welding portion connects active material coating part by gathering part, and welding portion is connected as a whole by first welding mark;Pole assembly is equipped at mounting hole and includes pole body, and pole body includes the first body and second body of different material, the first body has opposite first surface and second surface, and second surface is closer to containing cavity compared with first surface, electrode assembly is connected with second surface, and electrode assembly and pole body form second welding mark welded from first surface towards electrode assembly.The utility model can make that electrode assembly and the welding operation of pole body are easy, improve battery monomer reliability.

Description

[0001] Priority information

[0002] This application claims priority and benefit to patent application No. PCT / CN2025 / 088135, filed with the China National Intellectual Property Administration on April 9, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Technology

[0004] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, the power battery, as the power source, plays an irreplaceable and crucial role. A battery consists of a casing and multiple battery cells housed within it. As a core component of new energy vehicles, the battery has high requirements in terms of both safety and lifespan. In related technologies, the tabs in battery cells are welded through the terminal assembly, resulting in a complex terminal assembly structure and issues such as electrolyte leakage and solder joint contamination. Furthermore, the tabs need to be pre-extended beyond the terminal assembly, leading to excessively high local current, which can easily degrade battery performance and affect the reliability of the battery cells. Utility Model Content

[0005] This application provides a battery cell, a battery device, and an electrical device, which can effectively improve the reliability of the battery cell, the battery device, and the electrical device.

[0006] In a first aspect, embodiments of this application provide a battery cell, comprising: a housing assembly having a receiving cavity within it, a first housing wall having a mounting hole; an electrode assembly disposed within the receiving cavity, the electrode assembly including a tab group and an active material coating portion, the tab group being connected to one end of the active material coating portion near the mounting hole; the tab group including a welding portion and a retracting portion, the welding portion being connected to the active material coating portion via the retracting portion, the welding portion being connected as a whole by a first weld mark; and a terminal post assembly disposed at the mounting hole and including a terminal post body, the terminal post body including a first body and a second body, the first body being closer to the electrode assembly than the second body, and the first body and the second body being made of different materials, the first body having a first surface and a second surface opposite to each other, the second surface being closer to the receiving cavity than the first surface, the electrode assembly being connected to the second surface, and the electrode assembly and the terminal post body forming a second weld mark welded from the first surface toward the electrode assembly.

[0007] In the above technical solution, the electrode body is composed of a first body and a second body made of different materials, thereby forming a composite electrode structure. Moreover, the tab assembly is located inside the housing assembly. The welding part of the first body of the electrode assembly and the tab assembly is welded without perforation, so that the second weld mark is formed from the first surface to the second surface. By adopting the above solution, the welding operation of the electrode assembly and the electrode body in the battery cell with composite electrode is easy, and the second weld mark has high mechanical strength, the weld point distribution is more uniform, the assembly efficiency of the battery cell is improved, the performance of the battery cell is better, and thus the reliability of the battery cell is improved.

[0008] In some embodiments of this application, a groove is provided on the side of the first body away from the electrode assembly, and a portion of the second body is disposed in the groove and connected to the first body.

[0009] In the above technical solution, the second body is connected to the first body through a groove, thereby increasing the contact area between the two bodies. This increases the stress-bearing surface between them, improves the connection reliability, reduces the risk of breakage, and consequently reduces the failure risk of the electrode body. This improves the reliability of the electrode body, the electrode assembly, and the individual battery cells. Furthermore, the larger contact area between the second and first bodies also helps reduce the internal resistance of the electrode body, enhances its overcurrent capacity, and ultimately improves the electrical performance of the individual battery cells.

[0010] In some embodiments of this application, the terminal assembly includes an insulating and sealing structure, the second body includes a main body, a clamping part and an inserting part, the main body, the clamping part and the first body together form a clamping groove, the battery cell includes a clamped part, the clamping groove is clamped to the clamped part by the insulating and sealing structure, the inserting part is connected to the main body and disposed in the inserting groove, and in the direction of the main body pointing to the wall of the mounting hole, the size of the inserting part is larger than the size of the main body.

[0011] In the above technical solution, by making the size of the insert larger than that of the main body in the direction of the hole wall pointing to the mounting hole, on the one hand, the mating surface between the insert and the groove can be increased, the connection strength between the insert and the first main body can be improved, the risk of breakage of the first and second main bodies can be further reduced, the reliability of the pole assembly can be improved, and thus the reliability of the battery cell can be improved. On the other hand, it also makes the structure of the second body more compact and smaller in size, which can reduce the amount of material used, reduce the weight of the pole assembly, and improve the energy density of the battery cell.

[0012] In some embodiments of this application, the main body is an annular structure and has a first inner side away from the insulating sealing structure, and the embedded part has a second inner side away from the insulating sealing structure, and the second inner side and the first inner side are coplanar.

[0013] In the above technical solution, by making the second inner side of the embedded part coplanar with the first inner side of the main body, the probability of a protruding structure appearing in the hollow area inside the main body can be reduced, increasing the space of the hollow area. This facilitates the entry of the welding torch when the first body and the electrode assembly are welded, improving welding reliability and thus improving the reliability of the electrode assembly, thereby improving the reliability of the battery cell. Furthermore, it can further improve the structural compactness of the second body and reduce the size and weight of the electrode assembly, further increasing the energy density of the battery cell.

[0014] In some embodiments of this application, a plane parallel to the first shell wall is formed, the clamped part forms a first projection on the plane, the embedded part forms a second projection on the plane, and the second projection and the first projection partially overlap.

[0015] In the above technical solution, since the first projection of the clamped part on the plane and the second projection of the embedded part on the plane partially overlap, the clamped part can at least partially press the embedded part together with the insulating sealing structure, reducing the risk of failure of the joint surface of the embedded part and the groove due to tensile stress. This can further improve the connection reliability of the embedded part and the first body, thereby improving the reliability of the electrode assembly, and thus improving the reliability of the battery cell.

[0016] In some embodiments of this application, in the direction from the main body to the wall of the mounting hole, the size of the overlapping area of ​​the second projection and the first projection is L1, wherein 0.3mm≤L1≤1mm.

[0017] In the above technical solution, by setting the size of the overlapping area of ​​the second projection and the first projection within the above range, not only can the clamped part and the insulating sealing structure have a better pressing effect on the embedded part, but the effect of reducing the failure of the joint surface of the embedded part and the groove due to tensile stress is also better. It is also beneficial to make the structure of the second body more compact, reduce the size and weight of the second body, and improve the energy density of the battery cell.

[0018] In some embodiments of this application, the first body has a first face near the first shell wall, the insert has a second face near the first shell wall, the second face and the first face are flush, or the second surface is provided on the side of the first face near the first shell wall.

[0019] In the above technical solution, the risk of the embedded part being deeply embedded in the groove due to the second face being located below the second face can be reduced, thereby reducing the risk of the joint surface between the embedded part and the groove being reduced due to deep embedding. This also reduces the probability that the joint surface between the embedded part and the groove will be subjected to large tensile stress, thereby improving the connection reliability of the first body and the second body, and further improving the reliability of the pole assembly.

[0020] In some embodiments of this application, the height difference between the second facet and the first facet is H1, where 0 mm ≤ H1 ≤ 0.2 mm. In the above technical solution, by setting the height difference between the second facet and the first facet within the aforementioned range, the risk of excessive tensile stress caused by the deep embedding of the insert within the groove can be reduced, while simultaneously ensuring the insulation and sealing performance of the insulating and sealing structure corresponding to the position of the insert, thereby improving the reliability of the electrode assembly and consequently improving the reliability of the battery cell.

[0021] In some embodiments of this application, a dividing surface is formed along the thickness direction of the first body, equally dividing the maximum thickness of the first body. The embedded portion has a third surface portion away from the first shell wall, and the third surface portion is disposed close to the dividing surface. In the above technical solution, the embedded portion can have a suitable embedding depth within the first body, reducing the risk of a smaller residual wall thickness at the embedding portion location due to a larger embedding depth, thereby reducing the risk of weakening the structural strength of the first body. Furthermore, it also reduces the risk of a smaller mating surface between the embedded portion and the first body due to a smaller embedding depth, which could affect connection reliability. In other words, the above solution can further improve the connection reliability between the embedded portion and the first body.

[0022] In some embodiments of this application, the first body has a first facet close to the first shell wall, and the embedded portion has a third facet away from the first shell wall. The distance between the third facet and the first facet is H2, where 0.5mm ≤ H2. In the above technical solution, the portion of the second body embedded in the first body has a sufficiently large depth, which is beneficial to improving the strength and rigidity of the joint between the second body and the first body, thereby improving the connection reliability between the second body and the first body.

[0023] In some embodiments of this application, H2 ≤ 1 mm. In this technical solution, by setting H2 to be less than or equal to 1 mm, the risk of the second body being embedded too deeply into the first body can be reduced, the risk of large tensile stress caused by deep embedding can be reduced, the material used can be reduced, the weight of the electrode body can be reduced, and the energy density of the battery cell can be increased.

[0024] In some embodiments of this application, the first body has a fourth face away from the embedded part, and the distance between the fourth face and the third face is H3, wherein 1.5mm≤H3.

[0025] In the above technical solution, the weakest position of the first body can maintain a large strength and stiffness, thereby improving the overall strength and stiffness of the first body, reducing the risk of the first body breaking, improving the reliability of the first body, and thus improving the reliability of the electrode assembly, which in turn improves the reliability of the battery cell.

[0026] In some embodiments of this application, H3 ≤ 3mm. In this technical solution, by setting H3 to less than or equal to 3mm, the upper limit of H3 can be determined. This allows for a reduction in the thickness of the first body while ensuring high overall strength and rigidity, thus reducing material usage, saving internal space of the housing assembly, and providing more space for the electrode assembly, thereby improving the energy density of the battery cell.

[0027] In some embodiments of this application, the size of the embedded part is L2 in the direction from the main body to the wall of the mounting hole, wherein 1.5mm ≤ L2. In the above technical solution, by setting the minimum size of the embedded part in the direction from the main body to the wall of the mounting hole within the above range, the strength and rigidity of the embedded part can be improved, thereby improving the connection strength and reliability of the first body and the second body, improving the reliability of the electrode assembly, and thus improving the reliability of the battery cell.

[0028] In some embodiments of this application, L2 ≤ 3mm. In this technical solution, by setting L2 to less than or equal to 3mm, the width of the embedding part can be reduced while ensuring the overall strength and rigidity of the embedding part, thereby reducing the amount of material used and improving the energy density of the battery cell.

[0029] In some embodiments of this application, in the direction from the main body to the wall of the mounting hole, the elongation of the clamping part relative to the main body is greater than or equal to the elongation of the inserting part relative to the main body. In the above technical solutions, the clamping surface of the clamping part can completely cover the clamping part, reducing the risk of incomplete clamping at certain locations. This reduces the risk of tensile stress between the inserting part and the second body, further improving the connection reliability between the first body and the second body.

[0030] In some embodiments of this application, the groove has a groove width dimension in the direction of the main body pointing towards the wall of the mounting hole, and the groove width dimension gradually increases in the direction of the first body pointing towards the first shell wall, and the shape of the insert and the groove match.

[0031] In the above technical solution, by setting the insert and the groove as a shrinkage structure, the groove can provide a guiding role for the installation of the insert during the installation process of the insert and the groove, which can reduce the installation difficulty of the insert and the groove, improve the assembly efficiency, and help improve the installation quality of the second body on the first body, thereby improving the product yield of the pole body.

[0032] In some embodiments of this application, at least one end of the groove is provided with an arc portion in the direction of the main body pointing towards the wall of the mounting hole. In the above technical solution, by setting the groove to have an arc portion, the groove guides the embedded part, which is beneficial for assembly alignment and reduces assembly difficulty. At the same time, it also makes the inner surface of the groove more rounded, reducing the risk of stress concentration. This improves the reliability of the first body and thus improves the overall reliability of the pole post body.

[0033] In some embodiments of this application, the groove is conical. In this technical solution, both sides of the groove can serve as guides, resulting in better alignment of the insert and the groove, further reducing assembly difficulty and improving assembly efficiency.

[0034] In some embodiments of this application, the first body is provided with a clamping part, which is bent relative to the first body and clamped onto the insert part. In the above technical solution, the clamping part can fix the insert part in the groove, which can improve the connection reliability between the insert part and the first body. When the insert part and the first body are connected by welding, the riveting limit of the clamping part can reduce the welding requirements between the insert part and the first body while ensuring the connection reliability between the insert part and the first body, thereby reducing the welding difficulty.

[0035] In some embodiments of this application, the insulating sealing structure includes a sealing element, and the clamped portion is sealed to the second body and the first body through the sealing element. In the above technical solution, by providing a sealing element, the sealing performance between the clamped portion, the second body, and the first body can be guaranteed, thereby improving the reliability of the battery cell.

[0036] In some embodiments of this application, the thickness of the seal between the clamped portion and the embedded portion is H4, wherein 0.5mm ≤ H4 ≤ 0.75mm. In the above technical solution, by setting the thickness of the seal between the clamped portion and the embedded portion within the above range, it is possible to ensure good sealing while making the overall structure of the electrode assembly more compact and smaller in size, which is beneficial for improving the energy density of the battery cell.

[0037] In some embodiments of this application, the insulating sealing structure includes a first insulating member, at least a portion of which is disposed between the clamped portion and the first body and connected to the sealing member. In the above technical solution, by providing the first insulating member, the insulation between the clamped portion and the first body can be improved, thereby improving the reliability of the battery cell.

[0038] In some embodiments of this application, the insulating sealing structure includes a second insulating member, and a portion of the main body and the clamping portion are insulatedly connected to the clamped portion through the second insulating member. In the above technical solution, by providing the second insulating member, the insulation reliability between the second body and the clamped portion can be improved, the risk of insulation failure can be reduced, and thus the reliability of the battery cell can be improved.

[0039] In some embodiments of this application, the main body, the clamping part, and the embedding part are integrally formed; or, the main body and the embedding part are integrally formed, the clamping part and the main body are separate structures, the clamping part is provided with a second through hole, and the second body is installed in the second through hole.

[0040] In the above technical solutions, the main body, clamping part, and embedding part are integrally molded. This results in better overall consistency of the second body, higher structural strength and rigidity, and a lower risk of deformation failure, thus improving the reliability of the electrode assembly and consequently, the reliability of the battery cell. Alternatively, an integral molding of the main body and embedding part, while the clamping part and main body are separate structures, reduces the processing difficulty of the second body, which helps to lower costs and improve the product yield.

[0041] In some embodiments of this application, a portion of the first housing wall forms a clamped portion; or, the pole assembly includes an adapter connected to the first housing wall, a portion of the adapter forming a clamped portion.

[0042] In the above technical solution, when a portion of the first shell wall forms the clamping part, the clamping groove formed by the main body, clamping part, and first body in the second body can be directly used to clamp onto the first shell wall. With this structure, the pole assembly and shell assembly have fewer components, reducing assembly steps and improving assembly efficiency. Furthermore, the second body can be riveted to the first shell wall, simplifying the installation and reducing assembly difficulty, thus improving efficiency. When the pole assembly includes an adapter, with a portion of the adapter forming the clamping part, the first body, second body, and insulating sealing structure can be pre-assembled onto the adapter before the assembled assembly is installed onto the first shell wall. This reduces the assembly difficulty of the pole assembly and improves assembly efficiency.

[0043] In some embodiments of this application, the housing assembly includes an outer shell and an end cap. The outer shell has an opening, and the end cap covers the opening. A first shell wall is disposed on the outer shell or the end cap. In the above technical solutions, the first shell wall can be disposed on the outer shell or on the end cap, thereby providing more options for the design of the battery cell to meet different requirements.

[0044] In some embodiments of this application, the first body is made of copper and the second body is made of aluminum. In this technical solution, the electrode body is a copper-aluminum composite electrode. Using this composite electrode material not only provides good conductivity but also helps to reduce material costs.

[0045] In some embodiments of this application, the electrode body has a groove, the groove has a groove peripheral wall and a groove bottom wall, the end of the groove peripheral wall near the active material coating part is connected to the groove bottom wall, and the end away from the active material coating part defines the groove opening, the first body has a groove bottom wall, and the second body has a groove peripheral wall and a groove opening; wherein, the side surface of the groove bottom wall away from the receiving cavity is the first surface, the side surface of the groove bottom wall near the receiving cavity is the second surface, the second solder mark is formed on the groove bottom wall, and the groove bottom wall presses against the electrode assembly and is welded to the electrode assembly.

[0046] In the above technical solution, the groove makes the electrode body hollow, and the hollow structure has a slot, which facilitates the entry of the welding head during welding operations, and also helps to reduce the weight of the second body, thereby reducing the overall weight of the battery cell and increasing the energy density of the battery cell.

[0047] In some embodiments of this application, the electrode assembly includes a cover plate that covers the slot. The cover plate can seal the slot in the hollow part of the main body, which reduces the risk of chemical corrosion caused by the accumulation of dust, moisture, etc. on the inside of the main body, and helps to improve the reliability of the electrode assembly.

[0048] In some embodiments of this application, the second solder mark is located on the welding portion and the first body. In this technical solution, the welding portion is directly welded to the first body, thereby making the first body and the electrode assembly more compact in the height direction of the electrode body, which is beneficial to improving the overall compactness of the battery cell structure and thus improving the energy density of the battery cell.

[0049] In some embodiments of this application, the battery cell includes a conductive adapter block disposed between the welding part and the first body, and a second solder mark is disposed on the first body, the conductive adapter block and the welding part.

[0050] In the above technical solution, the conductive adapter block can be welded to both the welding part and the first body. The welding part and the first body are not directly welded; instead, they are connected via the conductive adapter block. Since the structure of the conductive adapter block can be designed to be relatively simple—for example, it can be an adapter plate or an adapter block—this helps reduce the structural complexity of the welding part, decrease the processing size of the electrode assembly, and reduce the processing difficulty of the electrode components. Furthermore, because the welding part and the first body are separated by the conductive adapter block, it also helps reduce the risk of welding through the welding part during welding, improving the reliability of the battery cells and thus improving the reliability of the battery device.

[0051] In some embodiments of this application, the second solder mark covers at least a portion of the first solder mark; the width of the second solder mark gradually decreases from the pole body towards the tab assembly, and the direction of its width intersects the direction of the pole body towards the tab assembly. In the above technical solution, the shape of the second solder mark with the above structure is relatively simple, which facilitates welding the welding portions of the first body and the tab assembly together on the outside of the pole body.

[0052] In some embodiments of this application, the cross-section of the second weld mark is U-shaped on a section plane perpendicular to the length direction of the welded part. In the above technical solution, the cross-sectional change trend of the second weld mark is relatively gentle, and the width at each point is relatively large, resulting in better strength at each point of the second weld mark, which can improve the connection reliability between the welded part and the first body.

[0053] In some embodiments of this application, the electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator, which are fabricated using a winding or stacking process. In this technical solution, the battery cell of this application is applicable to battery cells with an internal winding structure.

[0054] In some embodiments of this application, the housing assembly is a rigid structure or a pouch structure. It can be understood that the battery cell of this application can be a pouch battery or a rigid-cased battery, thus expanding the scope of application.

[0055] In some embodiments of this application, the housing assembly has a cuboid structure, or a flat and elongated structure. In this technical solution, the battery cell can be a prismatic battery, which expands the scope of application.

[0056] Secondly, embodiments of this application also provide a battery device, including a single battery cell as described above.

[0057] In the above technical solution, since the battery cell has high reliability, the battery device using the battery cell can have good reliability.

[0058] Thirdly, embodiments of this application also provide an electrical device, including a single battery cell as described above, or a battery device as described above.

[0059] In the above technical solution, since the battery cell or battery device has high reliability, it is beneficial to improve the reliability of the electrical device that uses the battery cell or battery device. Attached Figure Description

[0060] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0061] Figure 1 The electrical device provided in some embodiments of this application is a structural schematic diagram of a vehicle;

[0062] Figure 2 Exploded views of the structure of the battery device provided in some embodiments of this application;

[0063] Figure 3 This is a schematic diagram of the internal structure of a battery cell provided in some embodiments of this application;

[0064] Figure 4 for Figure 3 A magnified view of a portion of point I;

[0065] Figure 5 Exploded views of pole assembly provided in some embodiments of this application;

[0066] Figure 6 A partial structural schematic diagram of the pole post assembly provided in some embodiments of this application;

[0067] Figure 7 A partial structural schematic diagram of a pole post assembly provided in another embodiment of this application;

[0068] Figure 8 A partial structural schematic diagram of the pole post assembly provided in another embodiment of this application;

[0069] Figure 9 A partial structural schematic diagram of the pole assembly provided in another embodiment of this application;

[0070] Figure 10 Schematic diagram of a partial structure of a pole post assembly provided in other embodiments of this application Figure 1 ;

[0071] Figure 11 Schematic diagram of a partial structure of a pole post assembly provided in other embodiments of this application Figure 2 ;

[0072] Figure 12 A top view of a battery cell provided in some embodiments of this application;

[0073] Figure 13 A schematic diagram illustrating the assembly process of the pole post assembly and the first housing wall provided in some embodiments of this application;

[0074] Figure 14 This is a partially enlarged structural diagram of a battery cell provided in some other embodiments of this application.

[0075] icon:

[0076] 1000. Electrical appliances;

[0077] 100. Battery device;

[0078] 10. Box body; 11. First box body; 12. Second box body;

[0079] 20. Battery cell;

[0080] 21. Housing assembly; 2101. First housing wall; 21a. Mounting hole; 211. Housing; 212. End cap;

[0081] 22. Terminal assembly;

[0082] 221, pole body; 221a, clamping groove; 2001, clamped part; 2002, groove;

[0083] 2211, First body; 2211a, Groove; 2211b, First face surface; 2211c, Separating surface; 2211d, Fourth face surface; 2211e, Pressing part; 2211f, First surface; 2211g, Second surface;

[0084] 2212, Second body; 201, Main body portion; 201a, First inner surface; 201b, Arc portion; 202, Clamping portion; 202a, Second through hole; 203, Embedding portion; 203a, Second inner surface; 203b, Second face portion; 203c, Third face portion;

[0085] 222. Insulating and sealing structure;

[0086] 2221. Sealing element; 2201. First sealing part; 2202. Second sealing part; 2222. First insulating element; 2223. Second insulating element; 2203. First insulating part; 2204. Second insulating part;

[0087] 223. Cover plate;

[0088] 224. Adapter parts;

[0089] 23. Electrode assembly;

[0090] 231. Electrode assembly; 2311. Welding section; 2312. Retracting section;

[0091] 232. Active substance coating section;

[0092] 233. First solder mark; 234. Second solder mark;

[0093] 24. Conductive adapter block;

[0094] 200, Controller; 300, Motor; X, First direction; Y, Second direction; Z, Third direction. Detailed Implementation

[0095] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0096] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0097] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0098] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0099] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0100] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0101] In this application, "multiple" means two or more (including two).

[0102] In this application, the battery cell may include lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and the embodiments of this application are not limited to these. The battery cell may be cylindrical, flat, cuboid, or other shapes, and the embodiments of this application are not limited to these. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, square battery cells, and pouch battery cells, and the embodiments of this application are not limited to these.

[0103] The battery apparatus mentioned in the embodiments of this application can refer to an assembly of one or more battery cells for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar. In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0104] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0105] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing. As an example, the individual battery cell assembly may be a battery module, which can be housed within the housing by securing the battery module to the housing. Alternatively, the individual battery cell assembly may be housed within the housing by directly securing multiple individual battery cells to the housing. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0106] A single battery cell includes a casing assembly, electrode assembly, and electrolyte. The casing assembly houses the electrode assembly and electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrode plates. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, while the uncoated positive current collector protrudes beyond it, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the negative current collector without the negative active material layer protrudes from the one with the negative active material layer. The negative current collector without the negative active material layer serves as the negative electrode tab. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc. To ensure that a large current can be passed without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together.

[0107] The separator can be made of PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly can be a wound structure or a stacked structure; the embodiments of this application are not limited to these.

[0108] In recent years, new energy vehicles have experienced rapid development. In the field of electric vehicles, the power battery, as the power source, plays an irreplaceable and crucial role. A battery consists of a casing and multiple individual battery cells housed within it. As a core component of new energy vehicles, the battery faces high requirements in terms of both safety and cycle life.

[0109] In typical battery cells, the tabs are welded through the terminal assembly, and the tabs need to be pre-extended beyond the terminal assembly. However, the applicant has discovered that the external welding of the tab assembly to the terminal assembly through the hole must be done after electrolyte injection, which leads to problems such as electrolyte leakage and electrolyte contamination of the solder joints. Furthermore, the need for the tabs to extend beyond the casing increases internal space waste and can cause excessively high local current, which can easily lead to a decline in battery performance.

[0110] Based on the above considerations, in order to improve the above technical problems, this application provides a battery cell including a housing assembly, an electrode assembly, and a terminal assembly. The housing assembly has a receiving cavity and a first housing wall with a mounting hole. The electrode assembly is disposed in the receiving cavity and includes a tab group and an active material coating portion. The tab group is connected to the end of the active material coating portion near the mounting hole. The tab group includes a welding portion and a closing portion. The welding portion is connected to the active material coating portion through the closing portion, and the welding portion is connected as a whole by a first weld mark. The terminal assembly is disposed at the mounting hole and includes a terminal body. The terminal body includes a first body and a second body. The first body is closer to the electrode assembly than the second body, and the first body and the second body are made of different materials. The first body has a first surface and a second surface, and the second surface is closer to the receiving cavity than the first surface. The electrode assembly is connected to the second surface, and the electrode assembly and the terminal body form a second weld mark welded from the first surface toward the electrode assembly.

[0111] In the battery cell with the above-mentioned structure, with increasing emphasis on the performance of the battery cell, the battery cell of this application embodiment simplifies the welding operation of the tab group and the terminal assembly by designing the connection form of the tab group and the terminal assembly, and the welding effect is better, thereby improving the assembly efficiency and performance of the battery cell, improving the reliability of the battery cell, and further improving the reliability of the battery cell.

[0112] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. Electrical devices, etc., equipped with the batteries disclosed in this application can also be used.

[0113] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0114] For ease of explanation, the following embodiments use a vehicle as an example to illustrate an electrical device 1000 according to an embodiment of this application. Please refer to... Figure 1 , Figure 1The electrical device 1000 provided in some embodiments of this application is a structural schematic diagram of a vehicle. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle, and the battery device 100 can be located at the bottom, front, or rear of the vehicle. The battery device 100 can be used to power the vehicle; for example, the battery device 100 can serve as the vehicle's operating power source. The vehicle may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle during starting, navigation, and driving.

[0115] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle, but also as the driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0116] Reference Figure 2 , Figure 2 This is an exploded view of the structure of a battery device 100 provided in some embodiments of this application. The battery device 100 includes a housing 10 and a plurality of battery cells 20, which are housed within the housing 10. The housing 10 provides assembly space for the battery cells 20, and the housing 10 can adopt various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which overlap each other, and together define an assembly space for accommodating the battery cells 20. The second housing body 12 may be a hollow structure open at one end, and the first housing body 11 may be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 together define the assembly space; alternatively, the first housing body 11 and the second housing body 12 may both be hollow structures open on one side, with the open side of the first housing body 11 covering the open side of the second housing body 12. Of course, the box 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as cylinder, cuboid, etc.

[0117] In the battery device 100, multiple battery cells 20 can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can also consist of multiple battery cells 20 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. The battery device 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0118] Reference Figure 2 , Figure 2 The following is an exploded view of the structure of a battery device 100 provided in some embodiments of this application. The battery device 100 may include multiple rows of battery cells 20, which may be arranged along the length of the housing 10, and each row of battery cells 20 may include multiple battery cells 20 arranged along the width of the housing 10; or, the multiple rows of battery cells 20 may be arranged along the width of the housing 10, and each row of battery cells 20 may include multiple battery cells 20 arranged along the length of the housing 10.

[0119] Each battery cell 20 can be a secondary battery or a primary battery. A secondary battery refers to a battery cell 20 that can be recharged after discharge to activate the active materials and continue to be used. It can also be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and this application embodiment is not limited in this regard. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes. For example, in... Figure 2 In the middle, the shape of the battery cell 20 is a cuboid.

[0120] According to some embodiments of this application, refer to Figure 3 , Figure 4 and Figure 5 This application provides a battery cell 20, including: a housing assembly 21, a terminal assembly 22, and an electrode assembly 23.

[0121] The housing assembly 21 has a receiving cavity and a first housing wall 2101 with a mounting hole 21a. The electrode assembly 23 is disposed in the receiving cavity and includes a tab assembly 231 and an active material coating portion 232. The tab assembly 231 is connected to the end of the active material coating portion 232 near the mounting hole 21a. The tab assembly 231 includes a welding portion 2311 and a retracting portion 2312. The welding portion 2311 is connected to the active material coating portion 232 through the retracting portion 2312, and the welding portion 2311 is connected as a whole by a first solder mark 233. The electrode post assembly 22 is disposed at the mounting hole 21a and includes an electrode post. The body 221 includes a first body 2211 and a second body 2212. The first body 2211 is closer to the electrode assembly 23 than the second body 2212, and the first body 2211 and the second body 2212 are made of different materials. The first body 2211 has a first surface 2211f and a second surface 2211g. The second surface 2211g is closer to the receiving cavity than the first surface 2211f. The electrode assembly 23 is connected to the second surface 2211g, and the electrode assembly 23 and the electrode body 221 have a second weld mark 234 formed from the first surface 2211f toward the electrode assembly 23.

[0122] The housing assembly 21 can refer to the structure used to house and protect the internal components of the battery cell 20. The shape of the housing assembly 21 can be, but is not limited to, a cuboid, a cube, a cylinder, etc., and the material can be, but is not limited to, metal materials (such as aluminum, stainless steel, etc.), plastic materials (such as polypropylene, polyamide, polyphenylene sulfide, etc.), composite materials (such as carbon fiber reinforced composite materials, aluminum-plastic film, etc.), or other materials resistant to electrolyte corrosion, etc.

[0123] The first shell wall 2101 can refer to one of a plurality of shell walls that enclose the shell assembly 21. For example, the shell assembly 21 can have a first direction X, a second direction Y, and a third direction Z, wherein the second direction Y can refer to a direction perpendicular to the first direction X and the third direction Z. For example, the first direction X is the length direction of the battery cell 20, the second direction is the width direction of the battery cell 20, and the third direction Z is the height direction of the battery cell 20. The first shell wall 2101 can refer to the shell wall at one or both ends of at least one of the first direction X, the second direction Y, and the third direction Z of the shell assembly 21. For example, referring to… Figure 3 The first shell wall 2101 can be the shell wall of the third Z-end of the shell assembly 21.

[0124] The terminal assembly 22 can refer to the component in the battery cell 20 that connects the internal electrode assembly 23 to the external circuit. The terminal body 221 can be a conductor, and its material can be, but is not limited to, metallic materials, such as copper, aluminum, or composite materials.

[0125] In the above scheme, the electrode post body 221 can be a split structure composed of multiple components. Specifically, the electrode post body 221 may include a first body 2211 and a second body 2212. The first body 2211 is disposed closer to the inner side of the housing assembly 21, and the second body 2212 is disposed closer to the outer side of the housing assembly 21. The connection method between the first body 2211 and the electrode assembly 23 can be welding, and may include, but is not limited to, ultrasonic welding, ultrasonic pre-welding + laser welding, resistance welding, pressure welding, brazing, or adhesive bonding. The electrode post assembly 22 of the above structure can be the positive electrode or the negative electrode of the battery cell 20. The second body 2212 can be used to connect to external conductive components, or can be connected to external conductive components through other components.

[0126] The first body 2211 and the second body 2212 can refer to components made of different materials, and may include, but are not limited to, copper, aluminum, nickel, etc. The second body 2212 is made of the same material as the externally welded conductive components (such as electrodes, etc.). For example, the second body 2212 can be aluminum, and the first body 2211 can be copper.

[0127] It is understandable that the electrode body 221 is made of composite material. On the one hand, this structure can balance material cost and conductivity. For example, the first body 2211 located inside the housing assembly 21 is made of copper, which can have high conductivity and facilitate efficient current conduction between the electrode body 221 and the electrode assembly 23. The second body 2212 on the outside can be made of aluminum, which can reduce cost while having good conductivity.

[0128] On the other hand, in order to ensure efficient current conduction between the electrode body 221 and the electrode assembly 23, the first body 2211 can be made of a material with high conductivity, which results in higher material costs. The second body 2212 needs to be welded to an external conductive component. For example, the conductive component can be a bar plate, which is made of aluminum, a material that is cheaper and has better conductivity. In this case, the material of the electrode is often different from that of the bar plate, which is not conducive to welding. In this case, the materials of the first body 2211 and the second body 2212 are different, which can satisfy the requirements of efficient current conduction while also being conducive to welding to an external conductive component.

[0129] In the above technical solution, by setting the first body 2211 and the second body 2212 to be made of different materials, the electrode body 221 can be a composite material electrode, which can reduce costs while meeting the requirements of efficient current conduction, and also facilitates the welding of the electrode body 221 to external conductive components, thereby improving the manufacturability of the electrode body 221 and improving the product yield of the electrode assembly 22.

[0130] The tab assembly 231 includes a welding portion 2311 and a gathering portion 2312. The welding portion 2311 is connected to the active material coating portion 232 through the gathering portion 2312, and the welding portion 2311 is connected as a whole by a first solder mark 233. In some embodiments, multiple tabs can be gathered to form the gathering portion 2312, and the welding portion 2311 located at the end of the gathering portion 2312 is paired, glued, and then ultrasonically pre-welded to form the first solder mark 233.

[0131] For example, see reference Figure 4 The first surface 2211f and the second surface 2211g can be in the height direction of the pole body 221 (see...). Figure 4 The second surface 2211g is closer to the receiving cavity than the first surface 2211f in the height direction of the pole body 221. The welding portion 2311 of the tab assembly 231 is directly or indirectly connected to the second surface 2211g of the pole body 221. Here, the connection method between the tab assembly 231 and the pole body 221 is not limited, and may include, but is not limited to, ultrasonic welding, a combination of ultrasonic pre-welding and laser welding, resistance welding, pressure welding, brazing, bonding, etc.

[0132] The electrode assembly 23 and the electrode body 221 are welded together in the height direction of a portion of the electrode body 221 to form a second weld mark 234. The second weld mark 234 is exposed at the first surface 2211f, that is, exposed on the surface of the electrode body 221 away from the receiving cavity. At this time, the weld point between the electrode assembly 23 and the electrode body 221 is located on the outer surface of the electrode body 221. The welding tool can weld a portion of the electrode body 221 to the tab assembly 231. The second weld mark 234 formed during the welding process is located on the first surface 2211f of the electrode body 221 and extends through the electrode body 221 in the height direction to the second surface 2211g, so that the electrode body 221 and the tab assembly 231 are externally welded, giving the second weld mark 234 high mechanical strength and a more uniform weld point distribution.

[0133] Therefore, in the technical solution of this application embodiment, by setting the electrode assembly 23 on the side of the electrode post body 221 close to the receiving cavity, and performing non-perforated external welding between the electrode post body 221 and the electrode assembly 23, the second solder mark 234 is formed from the first surface 2211f towards the second surface 2211g. This simplifies the structure of the electrode post assembly 22, reduces electrolyte leakage and electrolyte contamination of the solder joints, and makes the welding operation easier, which is beneficial to improving the production efficiency of the battery cell 20. It also gives the second solder mark 234 high mechanical strength and more uniform solder joint distribution. In addition, the length of the tab assembly 231 can be reduced, which is beneficial to improving the performance of the battery cell 20, thereby improving the reliability of the battery cell 20.

[0134] In some embodiments, the electrode body 221 can be prepared by stamping or extrusion, which is a mature and low-cost process that helps improve the structural strength of the electrode body 221.

[0135] In some embodiments of this application, a groove 2211a is provided on the side of the first body 2211 away from the electrode assembly 23, and a portion of the second body 2212 is disposed within the groove 2211a and connected to the first body 2211. In battery cells of related technologies, since the terminal posts connect to the electrode assembly inside the housing assembly and are also used to connect to external conductive components (busbars, welding strips, etc.), and a sealing ring or other structure is provided between the terminal posts and the housing assembly, the terminal posts are subjected to a large force under the tensile force of the conductive components and the elastic force of the sealing ring, which leads to the risk of breakage and failure, thereby affecting the reliability of the terminal posts and thus the reliability of the battery cell.

[0136] In the above technical solution, the groove 2211a can refer to a groove structure provided on the first body 2211, and can be, but is not limited to, a rectangular groove, an arc groove, a toothed groove, etc. Since at least a portion of the insulating sealing structure 222 is located between the first body 2211 and the second body 2212, and the second body 2212 is directly or indirectly connected to the conductive component, the second body 2212 is easily subjected to elastic forces from the insulating sealing structure 222 and tensile forces from the conductive component. When the second body 2212 is subjected to a large force, since a portion of the first body 2211 can fit within the groove 2211a, and this portion can be connected to the first body 2211, there is a large mating surface and a large stress-bearing surface between the first body 2211 and the second body 2212. Therefore, the first body 2211 and the second body 2212 have a high connection strength, which can reduce the risk of breakage of the first body 2211 and the second body 2212.

[0137] The welding method between the mating surfaces of the second body 2212 and the groove 2211a can be, but is not limited to, welding, adhesive bonding, riveting, or screwing. When welding is used, it can be, but is not limited to, electromagnetic pulse welding, molecular diffusion welding, resistance welding, brazing, etc. Adhesive bonding can be, but is not limited to, conductive adhesive bonding, etc.

[0138] In the above technical solution, by configuring the electrode post body 221 to include a first body 2211 and a second body 2212, with the second body 2212 connected to the first body 2211 via a groove 2211a, the contact surface between the second body 2212 and the first body 2211 is increased. This increases the stress-bearing surface between the second body 2212 and the first body 2211, improves the connection reliability between the second body 2212 and the first body 2211, reduces the risk of breakage between the second body 2212 and the first body 2211, and thus reduces the failure risk of the electrode post body 221. This improves the reliability of the electrode post body 221, thereby improving the reliability of the electrode post assembly 22 and the battery cell 20. Furthermore, the larger contact surface between the second body 2212 and the first body 2211 also helps to reduce the internal resistance of the electrode post body 221, improves the overcurrent capacity, and thus improves the electrical performance of the battery cell 20.

[0139] In some embodiments of this application, reference is made to Figure 4 and Figure 5 The terminal assembly 22 includes an insulating sealing structure 222. The second body 2212 includes a main body 201, a clamping part 202, and an inserting part 203. The main body 201, the clamping part 202, and the first body 2211 together form a clamping groove 221a. The battery cell 20 includes a clamped part 2001. The clamping groove 221a is clamped to the clamped part 2001 by the insulating sealing structure 222. The inserting part 203 is connected to the main body 201 and is disposed in the inserting groove 2211a. In the direction from the main body 201 to the wall of the mounting hole 21a, the size of the inserting part 203 is larger than the size of the main body 201.

[0140] The insulating and sealing structure 222 can refer to a structure that plays a sealing and insulating role between the electrode body 221 and the first shell wall 2101, and can prevent the electrolyte leakage inside the battery cell 20, as well as prevent external air and moisture from entering the battery cell 20.

[0141] The second body 2212 may consist of at least three parts: a main body 201, a clamping part 202, and an inserting part 203. Optionally, the main body 201 may be an annular structure, and the clamping part 202 and the inserting part 203 may be annular structures arranged circumferentially around the main body 201, or multiple such structures may be arranged circumferentially along the main body 201. The clamped part 2001 may refer to an independent structural component of the battery cell 20, or it may be a partial structure of other structural components. The clamping groove 221a may be fixed to the clamped part 2001 by means of an insulating sealing structure 222. Optionally, referring to... Figure 4 The part of the structure of the first shell wall 2101 near the main body 201 is the clamped part 2001.

[0142] Optionally, "the direction in which the main body 201 points to the wall of the mounting hole 21a" can be... Figure 4 In the first direction X, in the direction from the main body 201 to the wall of the mounting hole 21a, the size of the insert 203 is larger than the size of the main body 201. This can be understood as the width of the insert 203 being greater than the width of the main body 201. Adaptively, the size of the groove 2211a matches the size of the insert 203, thereby increasing the mating surface between the insert 203 and the groove 2211a. Optionally, in the direction from the main body 201 to the wall of the mounting hole 21a, the size of the insert 203 can be larger than the size of the clamping part 202, or smaller than or equal to the size of the clamping part 202.

[0143] Optionally, the main body 201 and the clamping part 202 are arranged at an angle. Further, the main body 201 may be perpendicular to the clamping part 202. Optionally, the main body 201 and the inserting part 203 are arranged at an angle. Further, the main body 201 may be perpendicular to the inserting part 203. For example, the main body 201 and the clamping part 202 are generally L-shaped.

[0144] In the above technical solution, by making the size of the insert 203 larger than that of the main body 201 in the direction of the hole wall of the mounting hole 21a, on the one hand, the mating surface between the insert 203 and the groove 2211a can be increased, the connection strength between the insert 203 and the first body 2211 can be improved, the risk of breakage of the first body 2211 and the second body 2212 can be further reduced, the reliability of the pole assembly 22 can be improved, and thus the reliability of the battery cell 20 can be improved. On the other hand, it also makes the structure of the second body 2212 more compact and smaller in size, which can reduce the amount of material used, reduce the weight of the pole assembly 22, and improve the energy density of the battery cell 20.

[0145] In some embodiments of this application, reference is made to Figure 4 and Figure 5 The main body 201 has an annular structure and a first inner side 201a that is away from the insulating sealing structure 222. The embedded part 203 has a second inner side 203a that is away from the insulating sealing structure 222. The second inner side 203a and the first inner side 201a are coplanar.

[0146] Since the main body 201 has a ring-shaped structure, and the first inner surface 201a is also a ring-shaped surface, the main body 201 has a hollow structure. When the first body 2211 is connected to the electrode assembly 23 by welding, the hollow structure on the inner side allows the welding torch to enter for welding. Depending on the structure of the embedded part 203, the second inner surface 203a can be a ring-shaped surface, an arc-shaped surface, a straight surface, etc.

[0147] In the above technical solution, by making the second inner surface 203a of the embedded part 203 coplanar with the first inner surface 201a of the main body 201, the probability of a protruding structure appearing in the hollow area inside the main body 201 can be reduced, increasing the space of the hollow area. This facilitates the entry of the welding torch when the first body 2211 and the electrode assembly 23 are welded, improving welding reliability and thus improving the reliability of the electrode assembly 22, thereby improving the reliability of the battery cell 20. Furthermore, it can further improve the structural compactness of the second body 2212 and reduce the size and weight of the electrode assembly 22, further increasing the energy density of the battery cell 20.

[0148] In some embodiments of this application, reference is made to Figure 6 The clamped portion 2001 has a first projection on the plane parallel to the first shell wall 2101, and the embedded portion 203 has a second projection on the plane. The second projection and the first projection partially overlap.

[0149] In the above technical solution, since the first projection of the clamped part 2001 on the plane and the second projection of the embedded part 203 on the plane partially overlap, the clamped part 2001 can at least partially press the embedded part 203 together with the insulating sealing structure 222, reducing the risk of failure of the joint surface of the embedded part 203 and the groove 2211a due to tensile stress, which can further improve the connection reliability of the embedded part 203 and the first body 2211, thereby improving the reliability of the pole assembly 22, and thus improving the reliability of the battery cell 20.

[0150] In some embodiments of this application, reference is made to Figure 6 In the direction from the main body 201 to the wall of the mounting hole 21a, the size of the overlapping area of ​​the second projection and the first projection is L1, where 0.3mm≤L1≤1mm.

[0151] It is understandable that L1 can be, but is not limited to, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, etc. If L1 is less than 0.3mm, the overlapping area of ​​the second projection and the first projection is small, and the pressing area of ​​the clamped part 2001 and the insulating sealing structure 222 on the embedded part 203 is small. This increases the risk of failure of the mating surface of the embedded part 203 and the groove 2211a due to tensile stress. If L1 is greater than 1mm, it will result in excess pressing area of ​​the clamped part 2001 and the insulating sealing structure 222 on the embedded part 203, which may increase the size of the embedded part 203, increase the size and weight of the second body 2212, and is not conducive to improving the energy density of the battery cell 20.

[0152] In the above technical solution, by setting the size of the overlapping area of ​​the second projection and the first projection within the above range, not only can the clamped part 2001 and the insulating sealing structure 222 have a better pressing effect on the embedded part 203, but also the effect of reducing the failure of the joint surface of the embedded part 203 and the groove 2211a due to tensile stress is better. It also helps to make the structure of the second body 2212 more compact, reduce the size and weight of the second body 2212, and improve the energy density of the battery cell 20.

[0153] In some embodiments of this application, reference is made to Figure 4 and Figure 5 The first body 2211 has a first surface 2211b near the first shell wall 2101, and the insert 203 has a second surface 203b near the first shell wall 2101, the second surface 203b and the first surface 2211b being flush. In other embodiments, see also... Figure 6 and Figure 7 The second face 203b is located on the side of the first face 2211b near the first shell wall 2101, that is, the second face 203b protrudes from the first face 203b.

[0154] In the above technical solution, the risk of the embedded part 203 being deeply embedded in the groove 2211a due to the second face 203b being located below the second face 203b can be reduced, thereby reducing the risk of the joint surface between the embedded part 203 and the groove 2211a being reduced due to deep embedding. This also reduces the probability that the joint surface between the embedded part 203 and the groove 2211a will be subjected to large tensile stress, thereby improving the connection reliability of the first body 2211 and the second body 2212, and further improving the reliability of the pole assembly 22.

[0155] In some embodiments of this application, reference is made to Figure 6 , Figure 7 and Figure 8 The height difference between the second face 203b and the first face 2211b is H1, where 0mm≤H1≤0.2mm.

[0156] It is understandable that H1 can be, but is not limited to, 0mm, 0.02mm, 0.04mm, 0.05mm, 0.07mm, 0.1mm, 0.12mm, 0.14mm, 0.16mm, 0.18mm, 0.2mm, etc. If H1 is less than 0mm, the embedded part 203 may be deeply embedded in the groove 2211a. If H1 is greater than 0.2mm, the embedded part 203 will protrude significantly from the first body 2211, thereby reducing the thickness of the insulating sealing structure 222 at the corresponding position and affecting the insulation and sealing performance.

[0157] In the above technical solution, by setting the height difference between the second face 203b and the first face 2211b within the above range, the risk of large tensile stress caused by the deep embedding of the embedded part 203 in the groove 2211a can be reduced, and at the same time the insulation and sealing of the insulating sealing structure 222 corresponding to the position of the embedded part 203 can be guaranteed, thereby improving the reliability of the pole assembly 22, and thus improving the reliability of the battery cell 20.

[0158] In some embodiments of this application, reference is made to Figure 7 The partition surface 2211c, which divides the maximum thickness of the first body 2211 equally in the thickness direction of the first body 2211, and the embedded part 203 has a third face 203c away from the first shell wall 2101, and the third face 203c is disposed close to the partition surface 2211c.

[0159] Reference Figure 7 The "thickness direction of the first body 2211" can be the first direction X. Since the first body 2211 has a groove 2211a, the thickness of the first body 2211 is not uniform, with regions of smaller thickness and regions of larger thickness. The dividing surface 2211c can refer to the surface that equally divides the regions of larger thickness in the first body 2211. Optionally, the third face surface 203c can be coplanar with the third face surface 03c, or the third face surface 203c can be approximately coplanar with the third face surface 203c.

[0160] In the above technical solution, the embedded part 203 can have a suitable embedding depth within the first body 2211, reducing the risk of a smaller residual wall thickness at the position of the embedded part 203 in the first body 2211 due to a larger embedding depth. This reduces the risk of weakening the structural strength of the first body 2211. Furthermore, it reduces the risk of a smaller mating surface between the embedded part 203 and the first body 2211 due to a smaller embedding depth, thus affecting the connection reliability. In other words, the above solution can further improve the connection reliability between the embedded part 203 and the first body 2211.

[0161] In some embodiments of this application, reference is made to Figure 5 and Figure 6 The first body 2211 has a first face 2211b close to the first shell wall 2101, and the insert 203 has a third face 203c away from the first shell wall 2101. The distance between the third face 203c and the first face 2211b is H2, wherein 0.5mm≤H2.

[0162] H2 can be, but is not limited to, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, etc. If H2 is less than 0.5mm, correspondingly, the depth of the groove 2211a is less than 0.5mm, the embedding depth of the embedding part 203 on the first body 2211 is smaller, and the rigidity of the joint area between the embedding part 203 and the first body 2211 is also smaller, affecting the connection strength between the second body 2212 and the first body 2211.

[0163] In the above technical solution, the portion of the second body 2212 embedded in the first body 2211 has a sufficiently large depth, which is beneficial to improving the strength and rigidity of the joint between the second body 2212 and the first body 2211, thereby improving the connection reliability between the second body 2212 and the first body 2211.

[0164] In some embodiments of this application, H2 ≤ 1 mm. In this technical solution, by setting H2 to be less than or equal to 1 mm, the risk of the second body 2212 being embedded too deeply into the first body 2211 can be reduced, the risk of large tensile stress caused by deep embedding can be reduced, the amount of material used can be reduced, the weight of the electrode body 221 can be reduced, and the energy density of the battery cell 20 can be increased.

[0165] In some embodiments of this application, reference is made to Figure 6 The first body 2211 has a fourth face 2211d that is far from the embedded part 203. The distance between the fourth face 2211d and the third face 203c is H3, wherein 1.5mm≤H3.

[0166] The distance H3 between the fourth face 2211d and the third face 203c can refer to the residual wall thickness at the slotted location of the first body 2211. H3 can be, but is not limited to, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, 1.85mm, 1.9mm, 1.95mm, 2mm, 2.2mm, 2.5mm, etc. If H3 is less than 1.5mm, the residual wall thickness at the slotted location of the first body 2211 is less than 1.5mm. As this is a relatively weak location for the first body 2211, a smaller wall thickness will reduce the strength and stiffness of the first body 2211, increasing the risk of fracture.

[0167] In the above technical solution, the above solution enables the weakest position of the first body 2211 to maintain a large strength and stiffness, thereby improving the overall strength and stiffness of the first body 2211, reducing the risk of the first body 2211 breaking, improving the reliability of the first body 2211, and thus improving the reliability of the electrode assembly 22, which in turn improves the reliability of the battery cell 20.

[0168] In some embodiments of this application, H3 ≤ 3mm. In this technical solution, by setting H3 to less than or equal to 3mm, the upper limit of H3 can be determined. This allows for a reduction in the thickness of the first body 2211 while ensuring high overall strength and rigidity, thus reducing material usage, saving space inside the housing assembly 21, and providing more space for the electrode assembly 23, thereby increasing the energy density of the battery cell 20.

[0169] In some embodiments of this application, reference is made to Figure 6 In the direction from the main body 201 to the wall of the mounting hole 21a, the size of the insert 203 is L2, wherein 1.5mm≤L2.

[0170] Optionally, "the direction in which the main body 201 points to the wall of the mounting hole 21a" can refer to the first direction X, or it can be understood as the width dimension of the insert 203. L2 can be, but is not limited to, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, etc. If L2 is less than 1.5mm, the width dimension of the insert 203 is small, the overall structural strength and rigidity are weak, which is not conducive to improving the connection strength of the first body 2211 and the second body 2212.

[0171] In the above technical solution, by setting the minimum size of the embedded part 203 in the direction of the main body 201 pointing to the wall of the mounting hole 21a within the above range, the strength and rigidity of the embedded part 203 can be improved, thereby improving the connection strength and connection reliability of the first body 2211 and the second body 2212, improving the reliability of the pole assembly 22, and thus improving the reliability of the battery cell 20.

[0172] In some embodiments of this application, L2 ≤ 3mm. In this technical solution, by setting L2 to less than or equal to 3mm, the width of the embedded part 203 can be reduced while ensuring that the embedded part 203 as a whole has high strength and rigidity, thereby reducing the amount of material used and improving the energy density of the battery cell 20.

[0173] In some embodiments of this application, in the direction from which the main body 201 points toward the wall of the mounting hole 21a, the elongation of the clamping part 202 relative to the main body 201 is greater than or equal to the elongation of the inserting part 203 relative to the main body 201.

[0174] Reference Figure 6 In the direction from the main body 201 to the wall of the mounting hole 21a, the extension of the clamping part 202 relative to the main body 201 can be L3, and the extension of the insert part 203 relative to the main body 201 can be L4, that is, L4 is greater than or equal to L3. Optionally, L4 can be equal to L3, and in the third direction Z, the clamping part 202 can just completely press against the protruding part of the insert part 203 relative to the main body 201. Optionally, L4 can also be greater than L3, and in the third direction Z, the clamping part 202 can not only completely press against the protruding part of the insert part 203 relative to the main body 201, but also cover the joint between the insert part 203 and the groove 2211a.

[0175] In the above technical solutions, the clamping surface of the clamping part 202 can completely cover the clamping part 202, reducing the risk that the clamping part 202 may not be able to be pressed in some places. This reduces the risk of tensile stress between the embedded part 203 and the second body 2212, and further improves the connection reliability of the first body 2211 and the second body 2212.

[0176] In some embodiments of this application, reference is made to Figure 7 and Figure 8 In the direction of the main body 201 pointing to the wall of the mounting hole 21a, the groove 2211a has a groove width dimension. In the direction of the first body 2211 pointing to the first shell wall 2101, the groove width dimension gradually increases, and the shape of the insert 203 and the groove 2211a are matched.

[0177] Optionally, the "direction of the main body 201 pointing to the wall of the mounting hole 21a" can be a first direction X, and the "direction of the main body 201 pointing to the wall of the mounting hole 21a" can be a third direction Z. It is understood that in the third direction Z, the groove 2211a is a groove structure with a gradually narrowing width, and correspondingly, the insert 203 is also a structure with a reduced width. Optionally, the groove 2211a and the insert 203 can be, but are not limited to, conical, trapezoidal, or irregularly shaped structures with at least one curved surface, etc.

[0178] In the above technical solution, by setting the insert 203 and the groove 2211a as a reduced structure, the groove 2211a can provide a guiding function for the installation of the insert 203 during the installation process of the insert 203 and the groove 2211a. This can reduce the installation difficulty of the insert 203 and the groove 2211a, improve the assembly efficiency, and help improve the installation quality of the second body 2212 on the first body 2211, thereby improving the product yield of the pole body 221.

[0179] In some embodiments of this application, reference is made to Figure 7 At least one end of the groove 2211a is provided with an arc portion 201b in the direction of the hole wall of the main body 201 pointing towards the mounting hole 21a.

[0180] It is understood that the groove 2211a can be a shrinkage groove structure with an arc portion 201b at one end in the first direction X, or it can be a shrinkage groove structure with an arc portion 201b at both ends in the first direction X.

[0181] In the above technical solution, by setting the groove 2211a to have a structure with an arc portion 201b, on the one hand, the groove 2211a has a guiding function for the embedded portion 203, which is conducive to assembly alignment and can reduce assembly difficulty. On the other hand, it can also make the inner surface of the groove 2211a more rounded, reducing the risk of stress concentration. This can improve the reliability of the first body 2211, which is also conducive to improving the overall reliability of the pole body 221.

[0182] In some embodiments of this application, reference is made to Figure 8 The groove 2211a is conical. In the above technical solution, the groove 2211a can play a guiding role on both sides of the first direction X, and the assembly and alignment effect of the insert 203 and the groove 2211a is better, which can further reduce the assembly difficulty and improve the assembly efficiency.

[0183] In some embodiments of this application, reference is made to Figure 9 The first body 2211 is provided with a pressing part 2211e, which is bent relative to the first body 2211 and clamped on the embedded part 203.

[0184] The clamping part 2211e can refer to a structure extending from the first body 2211 that can clamp the embedded part 203. Optionally, the clamping part 2211e can be a bent component formed on the first body 2211, and the embedded part 203 is fixed to the first body 2211 by riveting.

[0185] In the above technical solution, the clamping part 2211e can fix the embedded part 203 in the groove 2211a, which can improve the connection reliability between the embedded part 203 and the first body 2211. When the embedded part 203 and the first body 2211 are connected by welding, the riveting limit of the clamping part 2211e can reduce the welding requirements between the embedded part 203 and the first body 2211 while ensuring the connection reliability between the embedded part 203 and the first body 2211, thereby reducing the welding difficulty.

[0186] In some embodiments of this application, reference is made to Figures 4 to 9 The insulating sealing structure 222 includes a sealing element 2221, and the clamped part 2001 is sealed to the second body 2212 and the first body 2211 through the sealing element 2221.

[0187] The seal 2221 can refer to a structure or component used to isolate the interior of the battery cell 20 from the external environment, and the material can include, but is not limited to, rubber (e.g., nitrile rubber), plastic (e.g., polyolefins), etc. The seal 2221 can be understood as a ring-shaped structure arranged in a third direction Z around the electrode post body 221.

[0188] In the above technical solution, by setting the sealing element 2221, the sealing between the clamped part 2001, the second body 2212, and the first body 2211 can be guaranteed, thereby improving the reliability of the battery cell 20.

[0189] In some embodiments of this application, reference is made to Figure 4 , Figure 5 , Figure 7 and Figure 8 The sealing element 2221 may include a first sealing part 2201 and a second sealing part 2202. The first sealing part 2201 is sealed between the clamped part 2001, the first body 2211, and the embedded part 203. The second sealing part 2202 is connected to the first sealing part 2201 and is sealed between the clamped part 2001 and the body part 201.

[0190] Understandably, in the first direction X, the size of the first sealing portion 2201 is larger than that of the embedded portion 203. Therefore, the first sealing portion 2201 can cover the gap between the embedded portion 203 and the groove 2211a, improving the sealing reliability among the clamped portion 2001, the first body 2211, and the embedded portion 203. The second sealing portion 2202 can then provide a seal between the clamped portion 2001 and the main body 201. The first sealing portion 2201 and the second sealing portion 2202 are arranged at an angle; optionally, the first sealing portion 2201 is perpendicular to the second sealing portion 2202. Optionally, the thickness of the first sealing portion 2201 is greater than the thickness of the second sealing portion 2202.

[0191] In the above technical solution, by setting the seal 2221 to include a first sealing part 2201 and a second sealing part 2202, the seal 2221 has a more complex shape and a longer sealing path, which can reduce the risk of sealing failure and further improve the sealing reliability between the clamped part 2001, the first body 2211 and the second body 2212.

[0192] In some embodiments of this application, reference is made to Figure 6 The thickness of the seal 2221 between the clamped portion 2001 and the embedded portion 203 is H4, wherein 0.5mm≤H4≤0.75mm.

[0193] H4 can be, but is not limited to, 0.5mm, 0.55mm, 0.6mm, 0.65mm, 0.7mm, 0.75mm, etc. If H4 is less than 0.5mm, the compression thickness of the seal 2221 is small, which will affect the sealing performance and increase the risk of seal failure. If H4 is greater than 0.75mm, while achieving good sealing performance, it will lead to excessive sealing performance, increasing the overall size of the terminal assembly 22 and affecting the energy density of the battery cell 20.

[0194] In the above technical solution, by setting the thickness of the sealing member 2221 between the clamped part 2001 and the embedded part 203 within the above range, it is possible to make the overall structure of the pole assembly 22 more compact and the size smaller while ensuring good sealing performance, which is beneficial to improving the energy density of the battery cell 20.

[0195] In some embodiments of this application, reference is made to Figures 4 to 9 The insulating sealing structure 222 includes a first insulating member 2222, which is at least partially disposed between the clamped portion 2001 and the first body 2211 and is connected to the sealing member 2221.

[0196] The first insulating component 2222 can refer to a component used to reduce the risk of a short circuit between the clamped part 2001 and the first body 2211. The material of the first insulating component 2222 can be, but is not limited to, plastics (e.g., polyethylene, polypropylene, polycarbonate, polyamide), ceramics, etc.

[0197] In the above technical solution, by setting the first insulating member 2222, the insulation between the clamped part 2001 and the first body 2211 can be improved, thereby improving the reliability of the battery cell 20.

[0198] In some embodiments of this application, reference is made to Figures 4 to 9 The insulating sealing structure 222 includes a second insulating member 2223. A portion of the main body 201 and the clamping portion 202 are insulatedly connected to the clamped portion 2001 through the second insulating member 2223.

[0199] The second insulating component 2223 can refer to a component that reduces the risk of short circuit between the main body 201 and the clamping part 202 and the clamped part 2001. The material of the second insulating component 2223 can be, but is not limited to, plastics (e.g., polyethylene, polypropylene, polycarbonate, polyamide), ceramics, etc. Optionally, the second insulating component 2223 can be injection molded. The second insulating component 2223 and the sealing component 2221 are abutted or connected.

[0200] In the above technical solution, by setting the second insulating member 2223, the insulation reliability between the second body 2212 and the clamped part 2001 can be improved, the risk of insulation failure can be reduced, and thus the reliability of the battery cell 20 can be improved.

[0201] In some embodiments of this application, reference is made to Figures 4 to 9 The second insulating member 2223 includes a first insulating part 2203 and a second insulating part 2204. The first insulating part 2203 is insulatingly disposed between the clamping part 202 and the clamped part 2001, and between the main body part 201 and the clamped part 2001. The second insulating part 2204 is connected to the first insulating part 2203 and is insulatingly disposed between the outer side of the clamping part 202 and the clamped part 2001.

[0202] The first insulating portion 2203 and the second insulating portion 2204 are arranged at an included angle. Optionally, the first insulating portion 2203 is perpendicular to the second insulating portion 2204. Optionally, the thickness of the second insulating portion 2204 is greater than the thickness of the first insulating portion 2203. The first insulating portion 2203 and the second insulating portion 2204 can be integrally formed and can be, but are not limited to, plastic parts or injection-molded parts. Optionally, the first insulating portion 2203 and the second insulating portion 2204 can be separate structures. Further, the first insulating portion 2203 can be a plastic part, and the second insulating portion 2204 can be a rubber-coated injection-molded part.

[0203] In the above technical solution, by setting the second insulating member 2223 to include the first insulating part 2203 and the second insulating part 2204, the second insulating member 2223 has a more complex shape and a longer insulating interface, which can reduce the risk of insulation failure and further improve the insulation reliability between the clamped part 2001 and the second body 2212.

[0204] In some embodiments of this application, reference is made to Figures 4 to 9 The main body 201, the clamping part 202, and the inserting part 203 are integrally formed; or, refer to Figure 10 and Figure 11The main body 201 and the embedded part 203 are integrally formed, while the clamping part 202 and the main body 201 are separate structures. The clamping part 202 is provided with a second through hole 202a, and the main body 201 is installed in the second through hole 202a.

[0205] Reference Figures 4 to 9 The second body 2212 is a one-piece molded part, with one part bent to form the insert 203 and the other part bent to form the clamping part 202. (Refer to...) Figure 10 and Figure 11 The second body 2212 is a split structure, with the main body 201 and the embedded part 203 being a single piece. The clamping part 202 can be subsequently assembled and connected to the main body 201, for example, the clamping part 202 can be connected to the main body 201 by welding. When the second body 2212 is a split structure, the clamping part 202 is an annular structure arranged around a third direction Z. The hollow region of the annular structure forms a second through hole 202a, and the main body 201 is installed in the second through hole 202a.

[0206] In the above technical solution, the main body 201, clamping part 202, and embedding part 203 are integrally formed. This results in better overall consistency of the second body 2212, higher structural strength and rigidity, and a lower risk of deformation failure, thus improving the reliability of the electrode assembly 22 and consequently, the reliability of the battery cell 20. Alternatively, the solution of integrally forming the main body 201 and embedding part 203, while the clamping part 202 and main body 201 are separate structures, reduces the processing difficulty of the second body 2212, helps reduce costs, and improves the product yield of the second body 2212.

[0207] In some embodiments of this application, reference is made to Figures 4 to 9 The first shell wall 2101 forms the clamped portion 2001.

[0208] This can be understood as referring to Figures 4 to 9 The portion of the first shell wall 2101 near the main body 201 forms a clamped portion 2001, thereby allowing the first body 2211 and the second body 2212 to be directly mounted in the mounting hole 21a on the first shell wall 2101 via the insulating sealing structure 222.

[0209] In the above technical solution, in the second body 2212, the clamping groove 221a formed by the main body 201, the clamping part 202, and the first body 2211 can be directly used to clamp onto the first shell wall 2101. With this structure for the installation of the pole post assembly 22 and the shell assembly 21, the pole post assembly 22 has fewer parts, reducing assembly steps and improving assembly efficiency. Furthermore, using the above solution, the second body 2212 can be installed on the first shell wall 2101 by riveting, which is a simple installation method, reducing assembly difficulty and improving assembly efficiency.

[0210] In some embodiments of this application, reference is made to Figure 10 , Figure 11 and Figure 12 The pole assembly 22 includes an adapter 224, a portion of which forms a clamped portion 2001.

[0211] The adapter 224 can refer to a connecting component that connects the pole body 221 and the first housing wall 2101. Optionally, the adapter 224 can be an adapter plate. (See reference...) Figure 10 and Figure 11 The portion of the adapter 224 near the main body 201, defined by the dotted line, constitutes the clamped portion 2001.

[0212] In the above technical solution, the first body 2211, the second body 2212 and the insulating sealing structure 222 can be pre-assembled on the adapter 224, and then the assembled assembly components are installed together on the first shell wall 2101, thereby reducing the assembly difficulty of the pole assembly 22 and improving the assembly efficiency.

[0213] In some embodiments of this application, reference is made to Figure 3 The housing assembly 21 includes a housing 211 and an end cap 212. The housing 211 has an opening, and the end cap 212 covers the opening. A first housing wall 2101 is provided on the housing 211 or the end cap 212.

[0214] In the above technical solution, the first shell wall 2101 can be set on the outer shell 211 or on the end cover 212, thereby providing more options for the design of the battery cell 20 to meet different requirements.

[0215] In some embodiments of this application, reference is made to Figure 3 The first shell wall 2101 is provided on the end cover 212. Since the end cover 212 is welded to the outer shell 211 afterward, the mounting hole 21a can be manufactured before the end cover 212 is installed on the outer shell 211. This reduces the processing difficulty of the end cover 212, enhances manufacturability, and helps improve product yield.

[0216] In some embodiments of this application, the first body 2211 is made of copper and the second body 2212 is made of aluminum.

[0217] In the above technical solution, the electrode body 221 is a copper-aluminum composite electrode. Using this composite electrode material not only satisfies the requirement of good conductivity, but also helps to reduce material costs.

[0218] In some embodiments of this application, reference is made to Figure 4The electrode body 221 has a groove 2002, which has a groove peripheral wall and a groove bottom wall. The end of the groove peripheral wall near the active material coating part 232 is connected to the groove bottom wall, and the end away from the active material coating part 232 defines the groove opening of the groove 2002. The first body 2211 has a groove bottom wall, and the second body 2212 has a groove peripheral wall and a groove opening. The side surface of the groove bottom wall away from the receiving cavity is the first surface 2211f, and the side surface of the groove bottom wall near the receiving cavity is the second surface 2211g. The second solder mark 234 is formed on the groove bottom wall, and the groove bottom wall presses against the electrode assembly 23 and is welded to the electrode assembly 23.

[0219] It is understandable that the pole body 221 in the above scheme can be hollowed out, and the hollowed-out area forms a groove 2002. This makes it easier for the welding gun head of the welding equipment to enter when the pole body 221 and the welding part 2311 are externally welded, and can also reduce the thickness of some areas of the pole body 221, making it easier to weld through and weld to the welding part 2311 of the tab assembly 231.

[0220] In the above technical solution, the groove 2002 makes the electrode body 221 hollow, and the hollow structure has a slot, which facilitates the entry of the welding head during welding operations, and also helps to reduce the weight of the second body 2212, thereby reducing the overall weight of the battery cell 20 and improving the energy density of the battery cell 20.

[0221] In some embodiments of this application, reference is made to Figure 4 The pole assembly 22 includes a cover plate 223, which covers the slot. Optionally, the cover plate 223 and the main body 201 can be made of the same material or different material. For example, the main body 201 is made of aluminum, and the cover plate 223 is also made of aluminum. The cover plate 223 matches the shape of the annular structure and can be, but is not limited to, circular, rectangular, triangular, or elliptical shapes, etc.

[0222] In the above technical solution, the slot in the hollow position of the main body 201 can be sealed by the cover plate 223, which can reduce the risk of chemical corrosion caused by the accumulation of dust and moisture on the inside of the main body 201, and is conducive to improving the reliability of the pole assembly 22.

[0223] In some embodiments of this application, reference is made to Figure 4 The second weld mark 234 is located on the welding part 2311 and the first body 2211. In this technical solution, the welding part 2311 is directly welded to the first body 2211, which makes the first body 2211 and the tab assembly 231 more compact in the height direction of the electrode body 221, which is beneficial to improving the overall compactness of the battery cell 20 and thus improving the energy density of the battery cell 20.

[0224] In some embodiments of this application, reference is made to Figure 14 The battery cell 20 includes a conductive adapter block 24, which is disposed between the welding part 2311 and the first body 2211. A second solder mark 234 is disposed on the first body 2211, the conductive adapter block 24 and the welding part 2311.

[0225] The conductive adapter block 24 can connect the welding part 2311 and the first body 2211 in a manner that includes, but is not limited to, ultrasonic welding, ultrasonic pre-welding + laser welding, resistance welding, pressure welding, brazing, or adhesive bonding. The conductive adapter block 24 can be designed as a plate-like or block-like structure that fits snugly against the welding part 2311 and the first body 2211. Simultaneously, the conductive adapter block 24 must have good conductivity, allowing the current from the electrode assembly 231 to be conducted to the first body 2211 through the conductive adapter block 24. The conductive adapter block 24 has a certain thickness to prevent burn-through of the conductive adapter block 24, thereby reducing the risk of burn-through of the welding part 2311.

[0226] In the above technical solution, the conductive adapter block 24 can be welded to the welding part 2311 and the first body 2211 respectively. The welding part 2311 and the first body 2211 are not directly welded, but are connected by the conductive adapter block 24. Since the structure of the conductive adapter block 24 can be designed to be relatively simple, for example, it can be an adapter plate or an adapter block. This helps to reduce the structural complexity of the welding part 2311, reduce the processing size of the tab assembly 231, and reduce the processing difficulty of the electrode assembly 23. Moreover, since the welding part 2311 and the first body 2211 are separated by the conductive adapter block 24, it also helps to reduce the risk of welding the welding part 2311 through during welding, improve the reliability of the battery cell 20, and thus improve the reliability of the battery device 100.

[0227] In some embodiments of this application, reference is made to Figure 4 The second solder mark 234 covers at least part of the first solder mark 233; the width of the second solder mark 234 gradually decreases from the pole body 221 toward the tab assembly 231, and the direction of the width intersects the direction of the pole body 221 toward the tab assembly 231.

[0228] refer to Figure 4 For example, on the third direction X, the second solder mark 234 can be U-shaped, V-shaped, or semi-circular, etc. The width of the second solder mark 234 can be arranged perpendicular to the direction of the pole body 221 toward the tab assembly 231, or it can be set at an angle other than 90 degrees.

[0229] In the above technical solution, the second weld mark 234 with the above structure has a relatively simple shape, which makes it easy to weld the first body 2211 and the welding part 2311 of the tab assembly 231 together on the outside of the pole body 221.

[0230] In some embodiments of this application, the cross-section of the second weld mark 234 is U-shaped on a cross-section perpendicular to the length direction of the weld portion 2311.

[0231] Understandably, compared to a V-shaped cross-section, the U-shaped cross-section of the second weld 234 allows for a more gradual decrease in width and a smaller width difference between adjacent positions. This is beneficial for the second weld 234 to have higher strength at various height positions in the third direction Z.

[0232] In the above technical solution, the cross-sectional change trend of the second weld mark 234 is relatively gentle, and the width of each part is relatively large. The strength of each part of the second weld mark 234 is also better, which can improve the connection reliability between the welded part 2311 and the first body 2211.

[0233] In some embodiments of this application, the electrode assembly 23 includes a positive electrode sheet, a negative electrode sheet, and a separator. The positive electrode sheet, negative electrode sheet, and separator are fabricated into the electrode assembly 23 by a winding process or a stacking process. It is understood that the battery cell 20 of any of the preceding embodiments of this application is applicable to battery cells with an internal cell winding structure.

[0234] In some embodiments of this application, the housing assembly 21 is a rigid structure or a pouch structure. If the housing assembly 21 is a rigid structure, the battery cell 20 is a hard-shell battery, and the material of the housing assembly 21 can be a metal, such as an aluminum shell. The material of the housing assembly 21 can also be a composite material, such as rigid plastic. If the housing assembly 21 is a pouch structure, the battery cell 20 is a pouch battery.

[0235] It can be understood that the battery cell 20 in this application can be a pouch battery or a hard-shell battery, which can expand the scope of application.

[0236] In some embodiments of this application, the housing assembly 21 has a cuboid structure, or the housing assembly 21 has a flat and elongated structure. In this technical solution, the battery cell 20 can be a prismatic battery, which can expand the scope of application.

[0237] The battery cell 20 provided according to the embodiments of this application includes: a housing assembly 21, a terminal assembly 22, and an electrode assembly 23.

[0238] The housing assembly 21 is provided with a first housing wall 2101, and the first housing wall 2101 is provided with a mounting hole 21a.

[0239] The electrode assembly 22 includes an electrode body 221 and an insulating sealing structure 222. The electrode body 221 is insulated and sealed in the mounting hole 21a by the insulating sealing structure 222. The electrode body 221 includes a first body 2211 and a second body 2212. The first body 2211 is made of copper and has a groove 2211a. The second body 2212 is made of aluminum and includes a main body 201, a clamping part 202 and an inserting part 203. The inserting part 203 is disposed in the groove 2211a and welded to the first body 2211. The main body 201, the clamping part 202 and the first body 2211 together form a clamping groove 221a. The clamping groove 221a is clamped to the first shell wall 2101 by the insulating sealing structure 222.

[0240] The insulating sealing structure 222 includes a sealing element 2221, a first insulating element 2222, and a second insulating element 2223. The sealing element 2221 is a sealing ring, which is sealed between the first shell wall 2101, the first body 2211, and the embedded part 203. The first insulating element 2222 is a plastic part and is insulatingly disposed between the first body 2211 and the first shell wall 2101. The second insulating element 2223 is a plastic part and is insulatingly disposed between the first shell wall 2101 and the second body 2212.

[0241] The electrode assembly 23 is disposed inside the housing assembly 21 and is welded to the first body 2211.

[0242] Reference Figure 13 When assembling the battery cell 20 in the above embodiment, the first body 2211 made of copper and the second body 2212 made of aluminum are first extruded and formed, and then connected by electromagnetic pulse welding or molecular diffusion welding. Then, the sealing member 2221, the first insulating member 2222 and the second insulating member 2223 are assembled with the electrode body 221, and then the second body 2212 is riveted to the first shell wall 2101.

[0243] This application also provides a battery device 100, including a battery cell 20 as described in any of the preceding embodiments.

[0244] In the above technical solution, since the battery cell 20 has high reliability, the battery device 100 using the battery cell 20 can have good reliability.

[0245] This application also provides an electrical device 1000, including a battery cell 20 as described in any of the preceding embodiments, or a battery device 100 as described in the preceding embodiments.

[0246] In the above technical solution, since the battery cell 20 or battery device 100 has high reliability, it is beneficial to improve the reliability of the electrical device 1000 that uses the battery cell 20 or battery device 100.

[0247] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The above are merely preferred embodiments of this application and are not intended to limit the application. For those skilled in the art, unless otherwise specified, all implementation methods and optional implementation methods of this application can be combined to form new technical solutions. Unless otherwise specified, all technical features and optional technical features of this application can be combined to form new technical solutions. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: A housing assembly, wherein the housing assembly has a receiving cavity, and the housing assembly has a first housing wall, the first housing wall having mounting holes; An electrode assembly is disposed within the receiving cavity. The electrode assembly includes a tab group and an active material coating portion. The tab group is connected to one end of the active material coating portion near the mounting hole. The tab group includes a welding portion and a retracting portion. The welding portion is connected to the active material coating portion through the retracting portion. The welding portion is connected as a whole by a first solder mark. An electrode assembly is disposed at the mounting hole and includes an electrode body. The electrode body includes a first body and a second body. The first body is closer to the electrode assembly than the second body, and the first body and the second body are made of different materials. The first body has a first surface and a second surface opposite to each other. The second surface is closer to the receiving cavity than the first surface. The electrode assembly is connected to the second surface, and the electrode assembly and the electrode body form a second weld mark that is welded from the first surface toward the electrode assembly.

2. The battery cell according to claim 1, characterized in that, The first body has a groove on the side away from the electrode assembly, and a portion of the second body is disposed in the groove and connected to the first body.

3. The battery cell according to claim 2, characterized in that, The terminal assembly includes an insulating and sealing structure. The second body includes a main body, a clamping part, and an inserting part. The main body, the clamping part, and the first body together form a clamping groove. The battery cell includes a clamped part. The clamping groove is clamped to the clamped part by the insulating and sealing structure. The inserting part is connected to the main body and disposed in the inserting groove. In the direction from the main body to the wall of the mounting hole, the size of the inserting part is larger than the size of the main body.

4. The battery cell according to claim 3, characterized in that, The main body is an annular structure and has a first inner side away from the insulating sealing structure. The embedded part has a second inner side away from the insulating sealing structure. The second inner side and the first inner side are coplanar.

5. The battery cell according to claim 3, characterized in that, A plane parallel to the first shell wall is drawn, the clamped part forms a first projection on the plane, and the embedded part forms a second projection on the plane, the second projection and the first projection partially overlap.

6. The battery cell according to claim 5, characterized in that, In the direction from the main body to the wall of the mounting hole, the size of the overlapping area of ​​the second projection and the first projection is L1, where 0.3mm≤L1≤1mm.

7. The battery cell according to claim 3, characterized in that, The first body has a first face near the first shell wall, and the embedding part has a second face near the first shell wall. The second face is flush with the first face, or the second face is located on the side of the first face near the first shell wall.

8. The battery cell according to claim 7, characterized in that, The height difference between the second face and the first face is H1, where 0mm≤H1≤0.2mm.

9. The battery cell according to claim 3, characterized in that, The insert portion has a third face away from the first shell wall, which is disposed close to the dividing surface in the thickness direction of the first body.

10. The battery cell according to claim 3, characterized in that, The first body has a first face near the first shell wall, and the embedded part has a third face away from the first shell wall. The distance between the third face and the first face is H2, wherein 0.5mm≤H2.

11. The battery cell according to claim 10, characterized in that, H2≤1mm.

12. The battery cell according to claim 10, characterized in that, The first body has a fourth face away from the embedded part, and the distance between the fourth face and the third face is H3, wherein 1.5mm≤H3.

13. The battery cell according to claim 12, characterized in that, H3≤3mm.

14. The battery cell according to any one of claims 9 to 13, characterized in that, In the direction from the main body to the wall of the mounting hole, the size of the insert is L2, where 1.5mm≤L2.

15. The battery cell according to claim 14, characterized in that, L2≤3mm.

16. The battery cell according to any one of claims 3 to 13, characterized in that, In the direction from the main body to the wall of the mounting hole, the elongation of the clamping part relative to the main body is greater than or equal to the elongation of the inserting part relative to the main body.

17. The battery cell according to any one of claims 3 to 13, characterized in that, In the direction of the main body pointing towards the wall of the mounting hole, the groove has a groove width dimension, and in the direction of the first body pointing towards the first shell wall, the groove width dimension gradually increases, and the shape of the insert and the groove are matched.

18. The battery cell according to claim 17, characterized in that, At least one end of the groove is provided with an arc portion in the direction of the hole wall pointing from the main body to the mounting hole.

19. The battery cell according to claim 17, characterized in that, The groove is conical.

20. The battery cell according to any one of claims 3 to 13, characterized in that, The first body is provided with a clamping part, which is bent relative to the first body and clamped on the embedded part.

21. The battery cell according to any one of claims 3 to 13, characterized in that, The insulating sealing structure includes a sealing element, and the clamped portion is sealed to the second body and the first body through the sealing element.

22. The battery cell according to claim 21, characterized in that, The thickness of the seal between the clamped portion and the embedded portion is H4, wherein 0.5mm≤H4≤0.75mm.

23. The battery cell according to claim 21, characterized in that, The insulating sealing structure includes a first insulating element, which is at least partially disposed between the clamped portion and the first body, and is connected to the sealing element.

24. The battery cell according to claim 22 or 23, characterized in that, The insulating sealing structure includes a second insulating member, and a portion of the main body and the clamping portion are insulatedly connected to the clamped portion through the second insulating member.

25. The battery cell according to any one of claims 3 to 13, characterized in that, The main body, the clamping part, and the embedding part are integrally formed; or, the main body and the embedding part are integrally formed, the clamping part and the main body are separate structures, the clamping part is provided with a second through hole, and the main body is installed in the second through hole.

26. The battery cell according to any one of claims 3 to 13, characterized in that, A portion of the first shell wall forms the clamped portion; or, the pole assembly includes an adapter connected to the first shell wall, a portion of which forms the clamped portion.

27. The battery cell according to any one of claims 1 to 13, characterized in that, The housing assembly includes an outer shell and an end cap, the outer shell having an opening, the end cap covering the opening, and a first shell wall disposed on the outer shell or the end cap.

28. The battery cell according to any one of claims 1 to 13, characterized in that, The first body is made of copper, and the second body is made of aluminum.

29. The battery cell according to any one of claims 1 to 13, characterized in that, The electrode body has a groove, the groove has a groove peripheral wall and a groove bottom wall, the end of the groove peripheral wall near the active material coating part is connected to the groove bottom wall, and the end away from the active material coating part defines the groove opening, the first body is provided with the groove bottom wall, and the second body is provided with the groove peripheral wall and the groove opening; The first surface is the side of the bottom wall of the tank away from the receiving cavity, and the second surface is the side of the bottom wall of the tank close to the receiving cavity. The second solder mark is formed on the bottom wall of the tank, and the bottom wall of the tank presses against the electrode assembly and is welded to the electrode assembly.

30. The battery cell according to claim 29, characterized in that, The pole assembly includes a cover plate that covers the slot.

31. The battery cell according to any one of claims 1 to 13, characterized in that, The second solder mark is located on the welded portion and the first body.

32. The battery cell according to any one of claims 1 to 13, characterized in that, The battery cell includes a conductive adapter block disposed between the welding part and the first body, and the second solder mark is disposed on the first body, the conductive adapter block and the welding part.

33. The battery cell according to any one of claims 1 to 13, characterized in that, The second solder mark covers at least a portion of the first solder mark; the width of the second solder mark gradually decreases from the pole body toward the tab assembly, and the direction of the width intersects the direction of the pole body toward the tab assembly.

34. The battery cell according to claim 33, characterized in that, On a cross-section perpendicular to the length of the welded portion, the second weld mark has a U-shaped cross-section.

35. The battery cell according to any one of claims 1 to 13, characterized in that, The electrode assembly includes a positive electrode, a negative electrode, and a separator. The positive electrode, the negative electrode, and the separator are manufactured into the electrode assembly by a winding process or a stacking process.

36. The battery cell according to any one of claims 1 to 13, characterized in that, The housing assembly can be a rigid structure or a soft-pack structure.

37. The battery cell according to any one of claims 1 to 13, characterized in that, The housing assembly has a cuboid structure, or the housing assembly has a flat and slender structure.

38. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1 to 37.

39. An electrical appliance, characterized in that, Includes the battery cell as described in any one of claims 1 to 37, or the battery device as described in claim 38.

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