Battery cell and battery pack

Abstract

This application provides a battery cell and a battery pack, relating to the field of battery technology. The battery cell includes: a housing, an electrode assembly, an end cap, terminals, and a conductive element. The electrode assembly is disposed within the housing; the end cap is connected to the housing; the terminals are disposed within the end cap; the conductive element is disposed within the housing, and is located on the side of the end cap near the electrode assembly. The conductive element is electrically connected to the electrode assembly, and the side of the conductive element near the end cap is welded to the terminals. A first embossed area is provided on the side of the conductive element away from the end cap. The first embossed area and the terminals are opposite each other. The first embossed area has multiple first grooves, each first groove being arranged circumferentially along the terminals and forming a closed structure. The multiple first grooves are concentrically arranged and spaced apart. The battery cell provided in this application increases the surface roughness of the conductive element, thereby reducing the reflectivity of the conductive element to laser light, which helps to improve the welding yield between the terminals and the conductive element, thus improving the electrical performance and safety of the battery cell.

Description

Technical Field

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

[0002] The information disclosed in this background section is intended only to enhance the understanding of the general background of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art.

[0003] Battery cells are a crucial component of battery packs. During the production of battery cells, laser welding is typically used to connect the terminals and conductive components to achieve electrical connection. However, because the surface of the conductive components is relatively smooth and therefore highly reflective of the laser, welding defects can easily occur, affecting the electrical performance and safety of the battery cell. Utility Model Content

[0004] In view of this, the purpose of this application is to provide a battery cell and a battery pack, which aims to solve the technical problem of how to improve the electrical performance and safety of the battery cell.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, embodiments of this application provide a battery cell, comprising: a housing; an electrode assembly disposed within the housing; an end cap connected to the housing; a terminal post disposed within the end cap; and a conductive element disposed within the housing, wherein the conductive element is located on the side of the end cap near the electrode assembly, the conductive element is electrically connected to the electrode assembly, the side of the conductive element near the end cap is welded to the terminal post, and a first embossed area is provided on the side of the conductive element away from the end cap, the first embossed area and the terminal post are disposed opposite to each other, the first embossed area is provided with a plurality of first grooves, the first grooves are recessed in a direction away from the electrode assembly, each first groove is disposed along the circumference of the terminal post and forms a closed structure, and the plurality of first grooves are concentrically arranged and spaced apart.

[0006] In some embodiments of the first aspect, the conductive element is further provided with a second embossed area on the side away from the end cap. The second embossed area is located on the outer periphery of the first embossed area, and the second embossed area is provided with a plurality of second grooves. Each second groove is arranged along the circumference of the pole post, and the plurality of second grooves are arranged concentrically and spaced apart.

[0007] In some embodiments of the first aspect, at least a portion of the first groove is arranged in an annular shape along the circumference of the pole post; and / or, at least a portion of the second groove is arranged in an annular shape along the circumference of the pole post.

[0008] In some embodiments of the first aspect, the conductive element is further provided with a third embossed area on the side away from the end cap. The third embossed area is located on the outer periphery of the second embossed area, and the third embossed area is provided with a plurality of third grooves. Each third groove is arranged along the circumference of the pole post, and the plurality of third grooves are arranged concentrically and spaced apart.

[0009] In some embodiments of the first aspect, the spacing between two adjacent first grooves is less than the spacing between two adjacent second grooves, and the spacing between two adjacent second grooves is less than the spacing between two adjacent third grooves.

[0010] In some embodiments of the first aspect, the battery cell has a third direction, and at least one of the third grooves has a through hole extending along the third direction at its bottom.

[0011] In some embodiments of the first aspect, at least one of the third grooves has a plurality of through holes at the bottom, and the plurality of through holes are arranged at circumferential intervals along the pole post.

[0012] In some embodiments of the first aspect, at least one of the third grooves has a depth greater than the depth of each of the second grooves, and at least one of the third grooves has a depth greater than the depth of each of the first grooves.

[0013] In some embodiments of the first aspect, the electrode assembly includes a tab and an electrode body, the tab being connected to the side of the electrode body near the end cap, and includes a bent portion welded to the side of the conductive element near the end cap. The conductive element also has a fourth embossed area on the side away from the end cap, the fourth embossed area and the bent portion being disposed opposite to each other.

[0014] In some embodiments of the first aspect, the fourth embossed area is provided with a plurality of fourth grooves, the plurality of fourth grooves being arranged at intervals; and / or, the fourth embossed area is provided with a plurality of protrusions, the plurality of protrusions being arranged at intervals.

[0015] Secondly, embodiments of this application provide a battery pack including the battery cells described in any of the embodiments of the first aspect above.

[0016] The beneficial effects of this application are as follows: The battery cell provided in this application has a first embossed area on the side of the conductive component near the end cap, which is welded to the terminal post. The first embossed area is opposite to the terminal post and has multiple first grooves. Each first groove is arranged along the circumference of the terminal post and forms a closed structure. The multiple first grooves are concentrically arranged and spaced apart. This increases the surface roughness of the conductive component, thereby reducing the reflection of the conductive component to the laser. This helps to improve the welding yield between the terminal post and the conductive component, thus improving the electrical performance and safety of the battery cell.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] 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.

[0019] Figure 1 A three-dimensional structural schematic diagram of a battery cell in an embodiment of this application is shown; Figure 2 It shows Figure 1 A schematic diagram of the decomposed structure; Figure 3 A three-dimensional structural schematic diagram of the conductive element in some embodiments of this application is shown; Figure 4 It shows Figure 3 Schematic diagram of the cross-sectional structure at point AA; Figure 5 A three-dimensional structural schematic diagram of the conductive element is shown in some other embodiments of this application; Figure 6 A three-dimensional structural schematic diagram of the conductive element is shown in some embodiments of this application; Figure 7 It shows Figure 6 Schematic diagram of the cross-sectional structure at point BB; Figure 8 A three-dimensional structural schematic diagram of the conductive element is shown in some embodiments of this application.

[0020] Explanation of key component symbols: 100-Battery cell; 110-Housing; 120-Electrode assembly; 121-Taper; 1211-Bending portion; 122-Electrode body; 130-End cap; 140-Terminal post; 150-Conductive component; 151-First embossed area; 1511-First groove; 152-Second embossed area; 1521-Second groove; 153-Third embossed area; 1531-Third groove; 154-Through hole; 155-Fourth embossed area; 1551-Fourth groove; X-First direction; Y-Second direction; Z-Third direction. Detailed Implementation

[0021] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] In the description of this application, the terms "center", "longitudinal", "lateral", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Furthermore, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Moreover, "above" or "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below" or "below" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0024] In the description of this application, the terms "first," "second," etc., are used to distinguish different objects and should not be construed as indicating or implying a specific order or hierarchy, or implicitly specifying the number of technical features indicated. Therefore, a feature marked "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, the term "multiple" means two or more, unless otherwise explicitly defined.

[0025] In the description of this application, unless otherwise explicitly specified, the terms "installation," "connection," "attachment," etc., should be interpreted broadly. For example, they can refer to non-detachable connections (e.g., welding, riveting, etc.), detachable connections (e.g., snap-fit, screw-fit, plug-in, etc.), or integral structures; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction 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.

[0026] In the description of this application, the term "and / or" can be understood to mean three possibilities. For example, A and / or B can represent: A alone; A and B simultaneously; or B alone. Additionally, the character " / " generally indicates that the preceding and following objects have an "or" relationship.

[0027] In the description of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 80° to 90°, the two directions can be considered perpendicular; if the angle between two directions is 0° to 10°, the two directions can be considered parallel.

[0028] Battery cells are a crucial component of battery packs. During the production of battery cells, laser welding is typically used to connect the terminals and conductive components, establishing an electrical connection. However, because the surface of the conductive components is relatively smooth and highly reflective of the laser, poor welding can easily occur, such as incomplete solder joints or cracks. This can lead to abnormal phenomena like insufficient current flow and abnormal temperature rises, ultimately affecting the electrical performance and safety of the battery cell. Furthermore, the same problems arise when laser welding is used to connect the tabs to the conductive components.

[0029] like Figure 1 As shown, to solve the above-mentioned technical problems, embodiments of this application provide a battery cell 100, which relates to the field of battery technology and is mainly used in battery packs, so as to be indirectly used in electrical devices or energy storage devices in the form of battery packs. Of course, the battery cell 100 can also be directly used in electrical devices or energy storage devices without taking the form of a battery pack, and no specific limitation is made to the application scenarios of the battery cell 100 here.

[0030] For example, electrical devices can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools. Vehicles can be gasoline-powered cars, natural gas-powered cars, new energy vehicles, etc., and new energy vehicles can be pure electric vehicles, hybrid electric vehicles, range-extended electric vehicles, etc.; spacecraft can be airplanes, rockets, space shuttles, drones, spacecraft, etc.; electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys; power tools can be metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers; energy storage devices include energy storage containers, energy storage cabinets, energy storage power stations, wind power generation devices, solar power generation devices, mobile power devices, temporary power supply devices, etc.; no specific limitations are made on the types of electrical devices and energy storage devices here.

[0031] like Figures 1 to 3 As shown, the battery cell 100 provided in this embodiment includes: a housing 110, an electrode assembly 120, an end cap 130, a terminal post 140, and a conductive element 150.

[0032] The electrode assembly 120 is disposed within the housing 110; the end cap 130 is connected to the housing 110; the electrode post 140 is disposed within the end cap 130; the conductive element 150 is disposed within the housing 110, and the conductive element 150 is located on the side of the end cap 130 near the electrode assembly 120. The conductive element 150 is electrically connected to the electrode assembly 120, and the side of the conductive element 150 near the end cap 130 is welded to the electrode post 140. The side of the conductive element 150 away from the end cap 130 is provided with a first embossed area 151. The first embossed area 151 and the electrode post 140 are disposed opposite each other. The first embossed area 151 is provided with a plurality of first grooves 1511. The first grooves 1511 are recessed in the direction away from the electrode assembly 120. Each first groove 1511 is disposed along the circumference of the electrode post 140 and forms a closed structure. The plurality of first grooves 1511 are concentrically disposed and spaced apart.

[0033] For example, the closed structure consists of multiple grooves connected end to end. The closed shape can be rhomboid or circular. In this embodiment, a rhomboid shape is used for ease of processing. The materials of the end cap 130 and / or the shell 110 can be aluminum, aluminum alloy, copper, iron, stainless steel, plastic, etc., and no specific limitation is made here.

[0034] For example, the material of the conductive element 150 and / or the material of the electrode 140 may be a metallic conductive material (e.g., copper, aluminum, silver, gold, iron, nickel, etc.) or a non-metallic conductive material (e.g., carbon-based material, superconductor, semiconductor, etc.), without specific limitations.

[0035] It is understood that in the battery cell 100 provided in this embodiment, since the conductive component 150 is welded to the terminal post 140 on the side near the end cap 130, and the conductive component 150 is provided with a first embossed area 151 on the side away from the end cap 130, the first embossed area 151 and the terminal post 140 are arranged opposite to each other, and the first embossed area 151 is provided with a plurality of first grooves 1511. Each first groove 1511 is arranged along the circumference of the terminal post 140 and forms a closed structure, and the plurality of first grooves 1511 are concentrically arranged and spaced apart. This increases the surface roughness of the conductive component 150, thereby reducing the reflection effect of the conductive component 150 on the laser, which helps to improve the welding yield of the terminal post 140 and the conductive component 150, thus improving the electrical performance and safety of the battery cell 100.

[0036] like Figure 2 and Figure 3 As shown, in some embodiments, the conductive element 150 is further provided with a second embossed area 152 on the side away from the end cap 130. The second embossed area 152 is located on the outer periphery of the first embossed area 151 and is provided with a plurality of second grooves 1521. Each second groove 1521 is arranged along the circumference of the pole post 140, and the plurality of second grooves 1521 are concentrically arranged and spaced apart. This increases the range of the rough surface of the conductive element 150, which helps to further reduce the reflection effect of the conductive element 150 on the laser, thereby helping to further improve the welding yield of the pole post 140 and the conductive element 150.

[0037] like Figure 3 As shown, further, in the plurality of first grooves 1511, at least a portion of the first grooves 1511 are arranged in a ring shape along the circumference of the pole post 140; and / or, in the plurality of second grooves 1521, at least a portion of the second grooves 1521 are arranged in a ring shape along the circumference of the pole post 140.

[0038] It is understandable that by using the first groove 1511 and the second groove 1521 arranged in a ring shape, the surface roughness of the conductive element 150 can be increased more effectively, thereby helping to further reduce the reflection effect of the conductive element 150 on the laser.

[0039] like Figure 3 As shown, further, the conductive element 150 is provided with a third embossed area 153 on the side away from the end cap 130. The third embossed area 153 is located on the outer periphery of the second embossed area 152 and is provided with a plurality of third grooves 1531. Each third groove 1531 is arranged along the circumference of the pole post 140, and the plurality of third grooves 1531 are concentrically arranged and spaced apart. This further increases the range of the rough surface of the conductive element 150, thereby helping to further reduce the reflection of the conductive element 150 on the laser.

[0040] like Figure 3 and Figure 4As shown, further, the distance L1 between two adjacent first grooves 1511 is smaller than the distance L2 between two adjacent second grooves 1521, and the distance L2 between two adjacent second grooves 1521 is smaller than the distance L3 between two adjacent third grooves 1531, that is, L1 < L2 < L3. This design can be understood as follows: on the conductive component 150, the groove spacing near the pole post 140 is relatively small, resulting in lower roughness, while the groove spacing far from the pole post 140 is relatively large, resulting in higher roughness. In this way, the overall welding yield of the conductive component 150 and the pole post 140 can be higher.

[0041] like Figure 5 As shown, in a specific embodiment, the battery cell has a third direction Z, and at least one third groove 1531 has a through hole 154 extending along the third direction Z at its bottom.

[0042] Understandably, by setting the through hole 154, the part of the bottom of the third groove 1531 other than the through hole 154 becomes a fusible part; when the current passing through the conductive component 150 is too large, the part of the bottom of the third groove 1531 other than the through hole 154 is prone to melt and break, thereby cutting off the current inside the battery cell 100, which helps to reduce the risk of thermal runaway and explosion caused by excessive current, and improves the safety of the battery cell 100.

[0043] like Figure 5 As shown, further, at least one third groove 1531 has multiple through holes 154 at the bottom of the groove, and the multiple through holes 154 are arranged at intervals along the circumference of the pole post 140.

[0044] Understandably, the arrangement of multiple through holes 154 can make the resulting fuse structure weaker, thus making it easier to break when the current is too high and thus enabling the current to be cut off more promptly.

[0045] like Figure 6 and Figure 7 As shown, in another specific embodiment, the depth H3 of at least one third groove 1531 is greater than the depth H2 of each second groove 1521 and the depth H1 of each first groove 1511, i.e., H3 > H2, H3 > H1. This design can be understood as follows: the depth of at least one third groove 1531 is greater than that of the second groove 1521 and the first groove 1511, so that the residual material at the location where this part of the third groove 1531 is opened on the conductive element 150 is thinner, thus becoming a fusion part; when the current passing through the conductive element 150 is too large, the safety protection effect of cutting off the current by structural fracture can also be achieved.

[0046] like Figure 1 , Figure 2 and Figure 8As shown, in some embodiments, the electrode assembly 120 includes a tab 121 and an electrode body 122. The tab 121 is connected to the side of the electrode body 122 near the end cap 130. The tab 121 includes a bent portion 1211, which is welded to the side of the conductive member 150 near the end cap 130. The side of the conductive member 150 away from the end cap 130 is also provided with a fourth embossed area 155. The fourth embossed area 155 and the bent portion 1211 are disposed opposite to each other.

[0047] It is understandable that the fourth embossing area 155 can increase the surface roughness of the bent portion 1211 of the conductive part 150 corresponding to the tab 121. Therefore, when the conductive part 150 and the tab 121 are welded by laser, it helps to suppress the reflection of laser by the conductive part 150, thereby helping to improve the welding yield of the conductive part 150 and the tab 121.

[0048] like Figure 8 As shown, the fourth embossing area 155 is further provided with a plurality of fourth grooves 1551, which are arranged at intervals; and / or, the fourth embossing area 155 is provided with a plurality of protrusions, which are arranged at intervals.

[0049] It is understandable that by arranging multiple fourth grooves 1551 at intervals or multiple protrusions at intervals, the surface roughness of the corresponding position of the conductive component 150 can be increased, thereby suppressing the reflection of laser by the conductive component 150. Here, the structure of the fourth embossed area 155 is not specifically limited.

[0050] It should be noted that the battery cell 100 provided in this embodiment mainly relies on the movement of metal ions between the positive and negative electrode plates to operate. The battery cell 100 can be cuboid, cylindrical, flat, or other shapes; according to the packaging method, the battery cell 100 provided in this embodiment can be a square battery, a cylindrical battery, a pouch battery, etc.; according to the type of metal ions, the battery cell 100 provided in this embodiment can be a lithium-ion battery, a sodium-ion battery, etc.

[0051] Furthermore, according to the classification of the physical state of the electrolyte, the battery cell 100 provided in this embodiment can be a liquid battery, that is, it uses a liquid electrolyte. Exemplarily, the electrode post 140 may include a positive electrode post and a negative electrode post. The electrode assembly 120 may be manufactured using a winding process or a stacking process. The electrode assembly 120 may include an electrode body 122 and tabs 121. The tabs 121 include a positive tab and a negative tab. The electrode body 122 is immersed in the liquid electrolyte and includes a positive electrode sheet, a negative electrode sheet, and a separator layer. The separator layer is disposed between the positive electrode sheet and the negative electrode sheet. The material of the separator layer may be polypropylene, polyethylene, etc. The positive electrode sheet 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. The positive tab is connected to the positive current collector and to the positive electrode post. The negative electrode sheet 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. The negative tab is connected to the negative current collector and to the negative electrode post. Taking lithium ions as an example, the materials for the positive electrode current collector and the positive electrode tab can be aluminum, and the materials for the positive electrode active material layer can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganese oxide, etc.; the materials for the negative electrode current collector and the negative electrode tab can be copper, and the negative electrode active material can be graphite, silicon, etc.

[0052] Of course, the battery cell 100 provided in this embodiment can also be a solid-state battery, that is, a solid electrolyte, such as sulfide, oxide or polymer electrolyte. Solid electrolyte can replace the separator and liquid electrolyte, and has both ion conduction and isolation functions. The type of battery cell 100 is not specifically limited here.

[0053] It should be noted that, as Figures 1 to 3 as well as Figure 8 As shown, when the battery cell 100 has two mutually perpendicular directions X, Y, and Z, the end cap 130 is located on the side of the housing 110 along the third direction Z, the conductive element 150 is located on the side of the end cap 130 along the third direction Z near the electrode assembly 120, and the tab 121 is located on the side of the electrode body 122 along the third direction Z near the end cap 130. The conductive element 150 along the third direction Z near the end cap 130 is welded to the bent portion 1211 of the terminal post 140 and the tab 121, respectively. The side of the conductive element 150 away from the end cap 130 is provided with a first embossed area 151, a second embossed area 152, a third embossed area 153, and a fourth embossed area 155, respectively. The positive terminal post and the negative terminal post are spaced apart along the first direction X, and the positive tab and the negative tab are spaced apart along the first direction X. At the same time, when there are multiple electrode assemblies 120, the multiple electrode assemblies 120 are arranged along the second direction Y.

[0054] To address the aforementioned technical problems, embodiments of this application also provide a battery pack, including the battery cell 100 from any of the above embodiments.

[0055] It is understood that since the battery pack provided in this embodiment has the battery cell 100 in any of the above embodiments, it has all the beneficial effects of the battery cell 100, which will not be described in detail here.

[0056] In the description of this application, the terms "some embodiments," "one embodiment," "example," "specific example," "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In the description of this application, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0057] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A battery cell, characterized in that, include: Casing (110); An electrode assembly (120) is disposed within the housing (110); End cap (130) is connected to the housing (110); A pole post (140) is disposed on the end cap (130); A conductive element (150) is disposed inside the housing (110), and the conductive element (150) is located on the side of the end cap (130) near the electrode assembly (120). The conductive element (150) is electrically connected to the electrode assembly (120). The side of the conductive element (150) near the end cap (130) is welded to the pole post (140). The side of the conductive element (150) away from the end cap (130) is provided with a first embossed area (151). The first embossed area (151) and the pole post (140) are arranged opposite to each other. The first embossed area (151) is provided with a plurality of first grooves (1511). The first grooves (1511) are recessed in the direction away from the electrode assembly (120). Each first groove (1511) is arranged along the circumference of the pole post (140) and forms a closed structure. The plurality of first grooves (1511) are arranged concentrically and spaced apart.

2. The battery cell according to claim 1, characterized in that, The conductive element (150) is provided with a second embossed area (152) on the side away from the end cap (130). The second embossed area (152) is located on the outer periphery of the first embossed area (151), and the second embossed area (152) is provided with a plurality of second grooves (1521). Each second groove (1521) is arranged along the circumference of the pole post (140), and the plurality of second grooves (1521) are arranged concentrically and spaced apart.

3. The battery cell according to claim 2, characterized in that, At least a portion of the first groove (1511) is arranged in a ring shape along the circumference of the pole post (140); and / or, at least a portion of the second groove (1521) is arranged in a ring shape along the circumference of the pole post (140).

4. The battery cell according to claim 2, characterized in that, The conductive element (150) is provided with a third embossed area (153) on the side away from the end cap (130). The third embossed area (153) is located on the outer periphery of the second embossed area (152), and the third embossed area (153) is provided with a plurality of third grooves (1531). Each third groove (1531) is arranged along the circumference of the pole post (140), and the plurality of third grooves (1531) are arranged concentrically and spaced apart.

5. The battery cell according to claim 4, characterized in that, The distance between two adjacent first grooves (1511) is less than the distance between two adjacent second grooves (1521), and the distance between two adjacent second grooves (1521) is less than the distance between two adjacent third grooves (1531).

6. The battery cell according to claim 4, characterized in that, The battery cell has a third direction (Z), and at least one of the third grooves (1531) has a through hole (154) extending along the third direction (Z) at its bottom.

7. The battery cell according to claim 6, characterized in that, At least one of the third grooves (1531) has a plurality of through holes (154) at the bottom of the groove, and the plurality of through holes (154) are arranged at intervals along the circumference of the pole post (140).

8. The battery cell according to claim 4, characterized in that, At least one of the third grooves (1531) has a depth greater than the depth of each of the second grooves (1521), and at least one of the third grooves (1531) has a depth greater than the depth of each of the first grooves (1511).

9. The battery cell according to any one of claims 1 to 8, characterized in that, The electrode assembly (120) includes a tab (121) and an electrode body (122). The tab (121) is connected to the side of the electrode body (122) near the end cap (130). The tab (121) includes a bent portion (1211). The bent portion (1211) is welded to the side of the conductive element (150) near the end cap (130). The conductive element (150) is also provided with a fourth embossed area (155) on the side away from the end cap (130). The fourth embossed area (155) and the bent portion (1211) are arranged opposite to each other.

10. The battery cell according to claim 9, characterized in that, The fourth embossed area (155) is provided with a plurality of fourth grooves (1551), and the plurality of fourth grooves (1551) are arranged at intervals; and / or, the fourth embossed area (155) is provided with a plurality of protrusions, and the plurality of protrusions are arranged at intervals.

11. A battery pack, characterized in that, Includes the battery cell according to any one of claims 1 to 10.

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