Battery monomer, battery and electric device

Abstract

The utility model relates to a battery monomer, a battery and a power utilization device. The battery monomer comprises an electrode assembly accommodated in a shell, the electrode assembly is provided with an axial end face arranged in the axial direction of the electrode assembly, the axial end face comprises a tab area and an outer edge area, and the outer edge area is arranged outside the tab area in a surrounding mode; the current collecting plate is accommodated in the shell and is arranged on one side of the electrode assembly along the axial direction of the electrode assembly, the current collecting plate is arranged towards the axial end surface, the current collecting plate comprises a main body, an edge part and a folded edge, the edge part is arranged outside the main body in a surrounding manner, and the folded edge extends along the direction opposite to the electrode assembly relative to the edge part and is electrically connected with the shell; wherein the main body is provided with a welding part, the welding part is provided with a welding surface, the welding surface is attached to the tab area, the orthographic projection of the edge part and the orthographic projection of the folded edge on the axial end face in the axial direction of the electrode assembly jointly cover the outer edge area, and the edge part, the folded edge and the outer edge area are arranged at intervals. According to the battery monomer, the battery and the power utilization device, the damage probability of the electrode assembly can be reduced.

Description

Technical Field

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

[0002] In recent years, the new energy industry has received increasing attention, and batteries, as an important component of this industry, occupy a large market share. A battery is formed by connecting multiple individual cells in series, parallel, or a combination of both. Each individual cell includes electrode components and current collectors. When the current collector is pressed down and squeezed against the electrode components, the electrode components are easily damaged, affecting the battery's safety. Utility Model Content

[0003] Therefore, it is necessary to provide a battery cell, battery, and power device that can reduce the probability of damage to electrode components to address the above problems.

[0004] On one hand, this application provides a battery cell, characterized in that the battery cell comprises:

[0005] shell;

[0006] An electrode assembly, housed within the housing, has an axial end face disposed along its axial direction, the axial end face including a tab region and an outer edge region, the outer edge region being disposed circumferentially around the tab region of the electrode assembly; and

[0007] A current collector is housed within the housing and is arranged along the axial direction of the electrode assembly on one side of the electrode assembly, with the current collector facing the axial end face. The current collector includes a main body, an edge portion, and a folded edge. The edge portion is arranged around the main body in the circumferential direction of the current collector, and the folded edge extends relative to the edge portion in a direction away from the electrode assembly and is electrically connected to the housing.

[0008] The main body has a welding part with a welding surface. The welding surface is in contact with the tab area. The edge part and the folded edge together cover the outer edge area on the axial end face along the axial direction of the electrode assembly. The edge part and the folded edge are spaced apart from the outer edge area.

[0009] In some embodiments, the edge portion includes a first segment and a second segment, the first segment being connected to the body and the second segment being connected between the first segment and the folded edge; at least the distance between the second segment and the outer edge region gradually decreases radially outward from the collector plate.

[0010] In some embodiments, the cross-section of the second segment is arc-shaped.

[0011] In some embodiments, the distance between the folded edge and the connection point of the second segment and the outer edge region is L2, where 0.02mm≤L2≤0.1mm.

[0012] In some embodiments, the main body further includes a plurality of reinforcing portions, the welding portion includes a central welding portion and a plurality of outer welding portions, the outer welding portions and the reinforcing portions are alternately arranged outside the central welding portion along the circumference of the collector plate, and the outer welding portions and the reinforcing portions are both connected to the edge portion;

[0013] The surface of the reinforcing portion facing the electrode assembly is recessed relative to the welding surface in a direction away from the electrode assembly and is spaced apart from the tab region. The surface of the reinforcing portion facing away from the electrode assembly protrudes from the portion of the welding portion that has the welding surface and is parallel to the axial end face.

[0014] In some embodiments, the distance between the edge portion and the outer edge region gradually increases radially outward from the manifold.

[0015] In some embodiments, the main body further includes a plurality of reinforcing portions, the welding portion includes a central welding portion and a plurality of outer welding portions, the outer welding portions and the reinforcing portions are alternately arranged outside the central welding portion along the circumference of the collector plate, and the outer welding portions and the reinforcing portions are both connected to the edge portion;

[0016] The surface of the reinforcing portion facing the electrode assembly is recessed relative to the welding surface in a direction away from the electrode assembly and is spaced apart from the tab region. The surface of the reinforcing portion away from the electrode assembly protrudes from the portion of the welding portion having the welding surface and parallel to the axial end face. The edge portion protrudes from the surface of the reinforcing portion away from the electrode assembly.

[0017] In some embodiments, the width of the outer edge region is L4, where 2mm ≤ L4 ≤ 3mm.

[0018] On the other hand, this application provides a battery, characterized in that the battery comprises a battery cell as described in any of the above embodiments.

[0019] In addition, this application also provides an electrical device, characterized in that the electrical device includes the battery described in the above embodiments, the battery being used to provide electrical energy to the electrical device.

[0020] Compared with the prior art, this application has the following beneficial effects:

[0021] The aforementioned battery cells, batteries, and power devices all have their edges and folds projected onto the axial end face along the axis of the electrode assembly, collectively covering the outer edge region. Furthermore, the edges and folds are spaced apart from the outer edge region. Therefore, when the current collector is pressed down, the edges and folds will not contact the outer edge, and consequently, the current collector will not contact the outer edge region. This reduces the risk of damage to the outer edge region caused by the current collector's pressure, thereby reducing the risk of damage to the electrode assembly and improving battery safety. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a single battery cell in one embodiment of this application;

[0023] Figure 2 for Figure 1 A top view of the electrode assembly in the shown battery cell;

[0024] Figure 3 for Figure 1 The diagram shows the structure of a single battery cell after the cover has been removed.

[0025] Figure 4 for Figure 3 A top view of the battery cell shown;

[0026] Figure 5 for Figure 4 The cross-sectional view of the battery cell along the AA direction is shown.

[0027] Figure 6 for Figure 5 An enlarged schematic diagram of a local structure B in a single battery cell is shown.

[0028] Figure 7 for Figure 6 The diagram shows the structure of partial structure B in the battery cell after the casing has been removed.

[0029] Figure 8 for Figure 3 The diagram shows the structure of the current collector in a single battery cell.

[0030] Figure 9 for Figure 8 The cross-sectional view of the collector plate along the CC direction is shown.

[0031] Figure 10 for Figure 9 An enlarged schematic diagram of a local structure E in the collector disk shown;

[0032] Figure 11 for Figure 8 The cross-sectional view of the collector plate along the DD direction is shown.

[0033] Figure 12 for Figure 11An enlarged schematic diagram of a local structure F in the collector disk shown;

[0034] Figure 13 This is a schematic diagram of the structure of a single battery cell in another embodiment of this application;

[0035] Figure 14 for Figure 13 The diagram shows the structure of a single battery cell after the cover has been removed.

[0036] Figure 15 for Figure 14 A top view of the battery cell shown;

[0037] Figure 16 for Figure 15 The cross-sectional view of the battery cell along the GG direction is shown.

[0038] Figure 17 for Figure 16 An enlarged schematic diagram of a local structure H in a single battery cell is shown.

[0039] Figure 18 for Figure 14 The diagram shows the structure of the current collector in a single battery cell.

[0040] Figure 19 for Figure 18 The cross-sectional view of the collector plate along the JJ direction is shown.

[0041] Figure 20 for Figure 19 An enlarged schematic diagram of a local structure M in the collector disk shown;

[0042] Figure 21 for Figure 18 The cross-sectional view of the collector plate along the KK direction is shown;

[0043] Figure 22 for Figure 21 An enlarged schematic diagram of a local structure N in the collector disk shown.

[0044] Icon labels:

[0045] 100. Battery cell;

[0046] 10. Current collector; 20. Electrode assembly; 30. Housing; 40. Cover;

[0047] 11. Main body; 111. Welded part; 111a. Central welded part; 111b. Outer welded part; 111c. Welded surface; 112. Reinforcing part; 12. Edge part; 121a. First section; 121b. Second section; 13. Folded edge;

[0048] 21. Axial end face; 211. Ear region; 212. Outer edge region; 213. Inner edge region; 214. Center hole. Detailed Implementation

[0049] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0050] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are 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, and therefore should not be construed as a limitation of this application.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0053] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "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," "below," and "under" 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.

[0054] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0055] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0056] A battery consists of multiple individual cells, which are connected in series, parallel, or mixed configurations. The individual cells are cylindrical.

[0057] A single battery cell includes an electrode assembly and a current collector. When welding the tabs of the electrode assembly to the current collector, a tooling is first used to press down the current collector so that it can fit tightly against the tab. Then, the tab and the current collector are welded and fixed to ensure welding quality and improve the battery's current carrying capacity.

[0058] However, when the current collector presses down and squeezes against the electrode assembly, it can easily damage the electrode assembly, affecting battery safety. Careful research revealed that the main reason for this damage is that the electrode assembly has a wound structure. In the radial direction from the inside out, the outer edge region, closer to the axial end face of the electrode assembly, experiences the greatest radial pressure and force. When the current collector presses down and contacts the axial end face of the electrode assembly, the outer edge region is also squeezed by the current collector. Under the combined effects of the large radial force and the squeezing action of the current collector, the outer edge region is easily damaged, leading to electrode assembly damage and compromising battery safety.

[0059] Please refer to the following: Figures 1 to 12 To alleviate the aforementioned problems, this application provides a battery cell 100, which includes a housing, an electrode assembly 20, and a current collector 10. Both the electrode assembly 20 and the current collector 10 are housed within the housing. The electrode assembly 20 has an axial end face 21 disposed along its axial direction. The axial end face 21 includes a tab region 211 and an outer edge region 212. The outer edge region 212 is disposed circumferentially around the tab region 211 of the electrode assembly 20. The current collector 10 is disposed on one side of the electrode assembly 20 along its axial direction, and faces the axial end face 21. The current collector 10 includes a body 11, an edge portion 12, and a flange 13. The edge portion 12 is disposed circumferentially around the body 11, and the flange 13 extends relative to the edge portion 12 in a direction opposite to the electrode assembly 20 and is electrically connected to the housing. The main body 11 has a welding part 111, the welding part 111 has a welding surface 111c, the welding surface 111c is in contact with the tab region 211, the edge part 12 and the folded edge 13 are projected onto the axial end face 21 along the axial direction of the electrode assembly 20 to cover the outer edge region 212, and the edge part 12 and the folded edge 13 are spaced apart from the outer edge region 212.

[0060] As an example, the outer casing is cylindrical and includes a housing 30 and a cover 40. The housing 30 can be open at one end and closed at the other, or open at both ends. The cover 40 is disposed at the opening of the housing 30 and seals with the housing 30 to define the internal environment of the battery cell 100. When the electrode assembly 20 and the current collector 10 are disposed inside the housing, the housing can isolate the electrode assembly 20 and the current collector 10 from the external environment to reduce the impact of the external environment on the electrode assembly 20 and the current collector 10.

[0061] The electrode assembly 20 is the main component for charging and discharging the battery cell 100, and it has a wound structure. The axial end face 21 of the electrode assembly 20 also includes an inner edge region 213, which surrounds and forms a central hole 214 for electrolyte penetration. A tab region 211 is circumferentially disposed around the inner edge region 213, and an outer edge region 212 is circumferentially disposed around the tab region 211. The width of the outer edge region 212 is L4, where 2mm ≤ L4 ≤ 3mm (e.g., ...). Figure 2(As shown). Specifically, L4 is 2mm, 2.2mm, 2.4mm, 2.6mm, 2.8mm, or 3mm, but is not limited to the listed values; other unlisted values ​​within the range are also applicable. The width of the outer edge region 212 is the circumferential diameter of the outer edge region 212 in the radial direction of the electrode assembly 20. The tab region 211 of the axial end face 21 refers to the area covered by the flattened tab in the electrode assembly 20, while the inner edge region 213 and outer edge region 212 of the axial end face 21 are the regions located outside the flattened tab.

[0062] The main body 11 of the collector plate 10 is the portion of the collector plate 10 that is welded to the tab region 211 of the axial end face 21. The main body 11 has a welding part 111, which has a welding surface 111c. The welding surface 111c is positioned facing the electrode assembly 20 and is in contact with the tab region 211 of the axial end face 21 of the electrode assembly 20. After contact, the welding part 111 is welded to the tab region 211, thereby achieving the connection between the collector plate 10 and the electrode assembly 20. The area of ​​the welding surface 111c can be smaller than the area of ​​the tab region 211, and the welding surface 111c is partially in contact with the tab region 211. Alternatively, the area of ​​the welding surface 111c can be equal to the area of ​​the tab region 211, and the welding surface 111c overlaps and is in contact with the tab region 211. The specific configuration can be set as needed, as long as the orthographic projection of the welding surface 111c on the axial end face 21 completely falls within the tab region 211. The orthographic projection of the edge portion 12 onto the axial end face 21 falls entirely within the outer edge region 212, while the orthographic projection of the folded edge 13 onto the axial end face 21 at most falls within the outer edge region 212. The folded edge 13 extends relative to the edge portion 12 in a direction away from the electrode assembly 20 and is electrically connected to the housing to achieve the connection between the current collector 10 and the housing. As an example, the folded edge 13 is perpendicular to the axial end face 21.

[0063] The edge portion 12 and the folded edge 13, projected onto the axial end face 21 along the axial direction of the electrode assembly 20, together cover the outer edge region 212, and both the edge portion 12 and the folded edge 13 are spaced apart from the outer edge region 212. Therefore, when the current collector 10 is pressed down, the edge portion 12 and the folded edge 13 will not contact the outer edge, and consequently, the current collector 10 will not contact the outer edge region 212, thereby reducing the risk of damage to the outer edge region 212 due to pressure from the current collector 10 (resulting in powder shedding, short circuits, etc.), which in turn reduces the risk of damage to the electrode assembly 20 and improves battery safety.

[0064] Furthermore, according to the formula P (pressure) = F (force) / S (area of ​​contact), to achieve the same pressure, since the contact area between the current collector 10 and the axial end face 21 of the electrode assembly 20 is only the area of ​​the welding surface 111c, the contact area is reduced. The required pressure is also lower. In other words, under the design of this application, a smaller pressure is sufficient to ensure that the welding portion 111 of the current collector 10 can be pressed down and that the welding surface 111c fits tightly against the tab region 211.

[0065] Please see Figures 13 to 22 In some embodiments, the distance between the edge portion 12 and the outer edge region 212 (specifically as follows) Figure 17 As shown in L3, the distance between the edge portion 12 and the outer edge region 212 gradually increases outwards from the radial direction of the collector plate 10. This increases the distance between the edge portion 12 and the outer edge region 212, thereby ensuring that the edge portion 12 does not contact the outer edge region 212 when the collector plate 10 is pressed down, further reducing the risk of damage to the electrode assembly 20.

[0066] Please see Figures 5 to 7 In some embodiments, the edge portion 12 includes a first segment 121a and a second segment 121b, the first segment 121a being connected to the main body 11, and the second segment 121b being connected between the first segment 121a and the folded edge 13; at least the distance from the second segment 121b to the outer edge region 212 (specifically as shown in the figure) Figure 7 As shown in L1, the distance between the second segment 121b and the flange 13 gradually decreases radially outward from the collector plate 10, and the distance at the connection point of the second segment 121b and the flange 13 reaches its minimum. It can be understood that the connection point between the second segment 121b and the flange 13 can also be considered the lowest point of the flange 13. At this point, the lowest point of the flange 13 is relatively close to the axial end face 21. With the distance between the end face of the flange 13 away from the electrode assembly 20 and the axial end face 21 of the electrode assembly 20 remaining constant, the closer the lowest point of the flange 13 is to the axial end face 21, the larger the width of the flange 13 in the axial direction of the electrode assembly 20. This allows for maximizing the weldable area between the flange 13 and the housing 30 while ensuring that the outer edge region 212 of the electrode assembly 20 is not compressed, thereby improving the welding reliability and connection stability of the flange 13 and the housing 30.

[0067] like Figure 6 As shown, in some embodiments, the cross-section of the second segment 121b is arc-shaped. In this way, the second segment 121b can extend towards the electrode assembly 20 in a more rounded shape, making the stress distribution of the second segment 121b more balanced, reducing the risk of damage to the second segment 121b under stress, and helping to extend the service life of the current collector 10.

[0068] Please see Figure 6 and Figure 7In some embodiments, the distance between the connection point of the folded edge 13 and the second segment 121b and the outer edge region 212 is L2 (specifically as follows). Figure 7 As shown), 0.02mm ≤ L2 ≤ 0.1mm. Specifically, L2 can be 0.02mm, 0.04mm, 0.05mm, 0.06mm, 0.08mm, or 0.1mm, but is not limited to the listed values; other unlisted values ​​within the range also apply. Under this design, while ensuring that the outer edge region 212 of the electrode assembly 20 is not subjected to pressure, the weldable area of ​​the flange 13 and the housing 30 can be increased as much as possible, thereby improving the welding reliability and connection stability of the flange 13 and the housing 30.

[0069] In some embodiments, the main body 11 further includes a plurality of reinforcing portions 112, and the welding portion 111 includes a central welding portion 111a and a plurality of outer welding portions 111b. The outer welding portions 111b and the reinforcing portions 112 are alternately arranged outside the central welding portion 111a along the circumference of the manifold 10, and both the outer welding portions 111b and the reinforcing portions 112 are connected to the edge portion 12. The surface of the reinforcing portion 112 facing the electrode assembly 20 is recessed relative to the welding surface 111c in a direction away from the electrode assembly 20, and is spaced apart from the tab region 211. The surface of the reinforcing portion 112 facing away from the electrode assembly 20 protrudes from the portion of the welding portion 111 having the welding surface 111c and parallel to the axial end face 21 (e.g., Figure 6 As shown in Figure R, the R portion and the T portion together form the welded portion. The design of the reinforcing portion 112 results in a concave-convex structural change between the reinforcing portion 112 and the welded portion 111. This design helps to improve the mechanical strength of the manifold 10, thereby reducing the risk of deformation of the manifold 10 and extending its service life.

[0070] Specifically, such as Figures 17 to 22 As shown, it is worth mentioning that in the embodiment where the distance between the edge portion 12 and the outer edge region 212 gradually increases radially outward from the collector plate 10, the edge portion 12 also protrudes from the reinforcing portion 112 away from the surface of the electrode assembly 20.

[0071] This application also provides a battery, which includes the battery cell 100 described in any of the above embodiments.

[0072] The battery in this application has the effects described in any of the above embodiments, so it will not be repeated here.

[0073] This application also provides an electrical device, which includes a battery as described in any of the above embodiments, the battery being used to provide electrical energy to the electrical device.

[0074] The electrical device in this application has the effects described in any of the above embodiments, so it will not be repeated here.

[0075] The electrical devices can include, but are 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.

[0076] It should be understood that the technical solutions described in the embodiments of this application are not limited to the electrical devices described above.

[0077] Please see Figures 1 to 12 The aforementioned battery cell 100, battery, and power device, along with the orthographic projection of the edge portion 12 and the folded edge 13 onto the axial end face 21 along the axial direction of the electrode assembly 20, collectively cover the outer edge region 212, and both the edge portion 12 and the folded edge 13 are spaced apart from the outer edge region 212. Therefore, when the current collector 10 is pressed down, the edge portion 12 and the folded edge 13 will not contact the outer edge, and consequently, the current collector 10 will not contact the outer edge region 212, thereby reducing the risk of damage to the outer edge region 212 due to pressure from the current collector 10, and consequently reducing the risk of damage to the electrode assembly 20, thus improving battery safety.

[0078] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0079] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A battery cell, characterized in that, The battery cell includes: shell; An electrode assembly (20) is housed within the housing, and the electrode assembly (20) has an axial end face (21) disposed along its axial direction, the axial end face (21) including a tab region (211) and an outer edge region (212), the outer edge region (212) being disposed circumferentially around the tab region (211) of the electrode assembly (20); and A collector plate (10) is housed within the housing and is arranged along the axial direction of the electrode assembly (20) on one side of the electrode assembly (20). The collector plate (10) is disposed facing the axial end face (21). The collector plate (10) includes a main body (11), an edge portion (12), and a flange (13). The edge portion (12) is disposed around the main body (11) in the circumferential direction of the collector plate (10). The flange (13) extends relative to the edge portion (12) in a direction away from the electrode assembly (20) and is electrically connected to the housing. The main body (11) has a welding part (111), the welding part (111) has a welding surface (111c), the welding surface (111c) is in contact with the tab area (211), the edge part (12) and the folded edge (13) together cover the outer edge area (212) on the axial end face (21) along the axial direction of the electrode assembly (20), and the edge part (12) and the folded edge (13) are spaced apart from the outer edge area (212).

2. The battery cell according to claim 1, characterized in that, The edge portion (12) includes a first segment (121a) and a second segment (121b). The first segment (121a) is connected to the main body (11), and the second segment (121b) is connected between the first segment (121a) and the folded edge (13). The distance between at least the second segment (121b) and the outer edge region (212) gradually decreases radially outward from the collector plate (10).

3. The battery cell according to claim 2, characterized in that, The cross-section of the second segment (121b) is arc-shaped.

4. The battery cell according to claim 2, characterized in that, The distance between the connection point of the folded edge (13) and the second segment (121b) and the outer edge region (212) is L2, 0.02mm≤L2≤0.1mm.

5. The battery cell according to claim 2, characterized in that, The main body (11) also includes a plurality of reinforcing parts (112). The welding part (111) includes a central welding part (111a) and a plurality of outer welding parts (111b). The outer welding parts (111b) and the reinforcing parts (112) are alternately arranged outside the central welding part (111a) along the circumference of the collector plate (10), and the outer welding parts (111b) and the reinforcing parts (112) are both connected to the edge part (12). The surface of the reinforcing part (112) facing the electrode assembly (20) is recessed relative to the welding surface (111c) in a direction away from the electrode assembly (20) and is spaced apart from the tab region (211). The surface of the reinforcing part (112) facing away from the electrode assembly (20) protrudes from the portion of the welding part (111) that has the welding surface (111c) and is parallel to the axial end face (21).

6. The battery cell according to claim 1, characterized in that, The distance between the edge portion (12) and the outer edge region (212) gradually increases radially outward from the collector plate (10).

7. The battery cell according to claim 6, characterized in that, The main body (11) also includes a plurality of reinforcing parts (112). The welding part (111) includes a central welding part (111a) and a plurality of outer welding parts (111b). The outer welding parts (111b) and the reinforcing parts (112) are alternately arranged outside the central welding part (111a) along the circumference of the collector plate (10), and the outer welding parts (111b) and the reinforcing parts (112) are both connected to the edge part (12). The surface of the reinforcing portion (112) facing the electrode assembly (20) is recessed relative to the welding surface (111c) in a direction away from the electrode assembly (20) and is spaced apart from the tab region (211). The surface of the reinforcing portion (112) facing away from the electrode assembly (20) protrudes from the portion of the welding portion (111) having the welding surface (111c) and parallel to the axial end face (21). The edge portion (12) protrudes from the surface of the reinforcing portion (112) facing away from the electrode assembly (20).

8. The battery cell according to any one of claims 1 to 7, characterized in that, The width of the outer edge region (212) is L4, where 2mm ≤ L4 ≤ 3mm.

9. A battery, characterized in that, The battery comprises a battery cell as described in any one of claims 1 to 8.

10. An electrical device, characterized in that, The electrical device includes the battery as described in claim 9, the battery being used to provide electrical energy to the electrical device.

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