Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of batteries, the single battery comprises a cover plate body and a pole, the cover plate body is connected with a shell and covers a containing cavity, the cover plate body is provided with a pole hole, the pole penetrates through the pole hole, the pole is provided with a groove body, and the groove body penetrates through the pole in the thickness direction of the cover plate body; the pole comprises a pole body and a first flanging and riveting part, the first flanging and riveting part is located on the side, away from the electrode assembly, of the pole body and connected with the pole body, the first flanging and riveting part is provided with a first sinking table, and the first sinking table is located on the side, away from the electrode assembly, of the first flanging and riveting part; at least part of the sealing plate is located in the first sinking table and covers the groove body, and the electrode lug penetrates through the groove body and is connected with the sealing plate. According to the single battery, the groove body is formed in the pole, so that the weight of the pole can be reduced, the sealing plate is arranged in the first sinking table of the first flanging and riveting part to cover and seal the groove body, impurities are prevented from entering the groove body, the light weight of the single battery is realized, and the safety and the stability of the single battery are improved.

Description

Technical Field

[0001] This application belongs to the technical field of batteries, and particularly relates to a single cell and a battery pack. Background Art

[0002] The cover plate assembly in a single cell is mainly assembled from parts such as a pole column and a cover plate body. Generally, a connecting piece is required to connect the electrode assembly and the pole column in a single cell, with complex processes, numerous components, low yield, and insufficient product competitiveness. Summary of the Invention

[0003] Object of the Invention: The embodiments of this application provide a single cell and a battery pack, aiming to solve the technical problems of complex processes and low yield in connecting the electrode assembly to the pole column through a connecting piece.

[0004] Technical Solution: The embodiments of this application provide a single cell, including:

[0005] A housing having an accommodation cavity;

[0006] An electrode assembly located in the accommodation cavity, the electrode assembly including a pole group and a tab;

[0007] A cover plate assembly including a cover plate body and a pole column. The cover plate body is connected to the housing and seals the accommodation cavity. The cover plate body has a pole column hole, and the pole column passes through the pole column hole. The pole column has a groove body that penetrates the pole column along the thickness direction of the cover plate body. The pole column includes a pole column body and a first riveting part. The first riveting part is located on the side of the pole column body away from the electrode assembly and is connected to the pole column body. The first riveting part has a first counterbore, and the first counterbore is located on the side of the first riveting part away from the electrode assembly;

[0008] A sealing plate, at least part of the sealing plate is located in the first counterbore and seals the groove body, and the tab passes through the groove body and is connected to the sealing plate.

[0009] In some embodiments, the sealing plate includes a connected first sealing part and a second sealing part. The first sealing part is located in the first counterbore, and the second sealing part is located on the side of the first sealing part close to the electrode assembly and is spaced from the pole column body.

[0010] In some embodiments, along the width direction of the cover plate body, the distance between the second sealing part and the pole column body is G mm; along the thickness direction, the maximum dimension of the sealing plate is T mm, and the dimension of the first sealing part along the thickness direction is T1 mm. The single cell satisfies any one of the following characteristics:

[0011] a) 0.02 ≤ G ≤ 0.1;

[0012] b) 2 ≤ T ≤ 3;

[0013] c) 0.8 ≤ T1 ≤ 1.5;

[0014] d) 0.15 ≤ T - T1 ≤ 1.5.

[0015] In some embodiments, the first clinching part has a first mating surface, the sealing plate has a second mating surface, the first mating surface and the second mating surface are oppositely arranged along the width direction, and the first mating surface and the second mating surface are connected by welding.

[0016] In some embodiments, the portion where the first mating surface and the second mating surface are in contact with each other has a maximum dimension of H mm along the thickness direction, and the maximum dimension of the first counterbore along the thickness direction is T2 mm, satisfying: 0.25 ≤ H / T2 ≤ 0.8.

[0017] In some embodiments, a first guiding part is formed between one end of the first clinching part far from the electrode assembly and the first mating surface.

[0018] In some embodiments, a second guiding part is formed between one end of the sealing plate far from the electrode assembly and the second mating surface.

[0019] In some embodiments, a third guiding part is formed between the first sealing part and the second sealing part;

[0020] A fourth guiding part is formed between the bottom wall of the first counterbore and the pole column body;

[0021] The third guiding part and the fourth guiding part are oppositely arranged.

[0022] In some embodiments, the pole column includes a second clinching part, the second clinching part is located on the side of the pole column body close to the electrode assembly and is connected to the pole column body, and the second clinching part and the pole column body enclose a limiting groove;

[0023] The single cell includes a connecting part, the connecting part is located between the cover plate body and the electrode assembly and surrounds the second clinching part, and at least part of the connecting part is embedded in the limiting groove.

[0024] In some embodiments, the single cell includes a sealing member, the sealing member includes a first sealing section, a second sealing section and a third sealing section, the first sealing section is arranged between the pole column body and the cover plate body, the second sealing section is clamped between the cover plate body and the connecting part, the third sealing section is embedded in the limiting groove and is clamped between the pole column body and the connecting part, and the first sealing section is respectively connected to the second sealing section and the third sealing section.

[0025] Correspondingly, an embodiment of the present application provides a battery pack, including the above single cell.

[0026] Beneficial effects: The single cell of the embodiment of the present application includes a housing, an electrode assembly, a cover plate assembly, and a sealing plate. The housing has a receiving cavity; the electrode assembly is located in the receiving cavity, and the electrode assembly includes a pole group and a tab; the cover plate assembly includes a cover plate body and a pole post, the cover plate body is connected to the housing and seals the receiving cavity, the cover plate body has a pole post hole, the pole post passes through the pole post hole, the pole post has a groove body, and the groove body penetrates the pole post along the thickness direction of the cover plate body; the pole post includes a pole post body and a first riveting part, the first riveting part is located on the side of the pole post body away from the electrode assembly and is connected to the pole post body, the first riveting part has a first counterbore, and the first counterbore is located on the side of the first riveting part away from the electrode assembly; at least part of the sealing plate is located in the first counterbore of the first riveting part to seal the groove body, and the tab passes through the groove body and is connected to the sealing plate. By providing a groove body on the pole post in the present application, the weight of the pole post can be reduced, the sealing plate is arranged in the first counterbore of the first riveting part to seal the groove body, and the tab passes through the groove body and is connected to the sealing plate to realize the electrical connection between the tab and the pole post, which can prevent foreign matters from entering the groove body, realize the light weight of the single cell, and improve the safety and stability of the single cell.

[0027] The battery pack of the embodiment of the present application includes the above-mentioned single cell, so the battery pack can have all the technical features and beneficial effects of the above-mentioned single cell, which will not be elaborated here. Description of the drawings

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0029] Figure 1 is a schematic structural diagram of a single cell according to an embodiment of the present application;

[0030] Figure 2 is a top view of a single cell according to an embodiment of the present application;

[0031] Figure 3 is Figure 2 the A-A sectional view of

[0032] Figure 4 is Figure 2 the B-B sectional view of

[0033] Figure 5 and Figure 6 is Figure 4 the enlarged view of part C of

[0034] Figure 7 is a schematic structural diagram of a sealing plate according to an embodiment of the present application;

[0035] Figure 8 is a cross-sectional view of a sealing plate according to an embodiment of the present application;

[0036] Figure 9 is a schematic structural view of a pole column before stamping according to an embodiment of the present application;

[0037] Figure 10 is a schematic structural view of a pole column after stamping according to an embodiment of the present application;

[0038] Figure 11 is a cross-sectional view of a pole column after stamping according to an embodiment of the present application.

[0039] Reference numerals: 1, housing; 2, electrode assembly; 3, cover plate assembly; 4, sealing plate; 5, connecting portion; 6, seal; 10, accommodating cavity; 20, electrode group; 21, tab; 30, cover plate body; 31, pole column; 40, first sealing portion; 41, second sealing portion; 42, second mating surface; 43, second guiding portion; 44, third guiding portion; 60, first sealing section; 61, second sealing section; 62, third sealing section; 300, pole column hole; 310, groove body; 311, pole column body; 312, first riveting portion; 313, second riveting portion; 314, limiting groove; 3120, first sink; 3121, first mating surface; 3122, first guiding portion; 3123, fourth guiding portion; X, thickness direction; Y, width direction. Detailed implementation manners

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application.

[0041] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present application. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality of" means two or more, and "at least one" means one, two or more, unless otherwise specifically defined. In the description of the present application, "vertical" means completely vertical at 90° or almost completely vertical. For example, within the range of an included angle of 80° to 100°, it is considered vertical. Similarly, "parallel" means completely parallel or almost completely parallel. For example, within the range of 10° of complete parallelism, it is considered parallel.

[0042] The applicant notes that the cover plate assembly in the single cell mainly consists of parts such as pole columns and cover plate bodies assembled. Generally, a connecting piece is required to connect the electrode assembly and the pole column in the single cell, with complex processes, many components, low yield, and insufficient product competitiveness.

[0043] In view of this, the single cell of the embodiment of the present application includes a housing, an electrode assembly, a cover plate assembly, and a sealing plate. The housing has a receiving cavity; the electrode assembly is located in the receiving cavity, and the electrode assembly includes a pole group and a pole tab; the cover plate assembly includes a cover plate body and a pole column. The cover plate body is connected to the housing and seals the receiving cavity. The cover plate body has a pole column hole, and the pole column passes through the pole column hole. The pole column has a groove body that penetrates the pole column along the thickness direction of the cover plate body; the pole column includes a pole column body and a first riveting part. The first riveting part is located on the side of the pole column body away from the electrode assembly and is connected to the pole column body. The first riveting part has a first counterbore, and the first counterbore is located on the side of the first riveting part away from the electrode assembly; at least part of the sealing plate is located in the first counterbore of the first riveting part to seal the groove body, and the pole tab passes through the groove body and is connected to the sealing plate. By providing a groove body on the pole column in the present application, the weight of the pole column can be reduced. The sealing plate is arranged in the first counterbore of the first riveting part to seal the groove body, and the pole tab passes through the groove body and is connected to the sealing plate to realize the electrical connection between the pole tab and the pole column, which can prevent foreign matters from entering the groove body, realize the lightweight of the single cell, and improve the safety and stability of the single cell.

[0044] The following will describe the single cell and battery pack of the present application in detail with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0045] Figure 1 is a schematic structural diagram of a single cell according to an embodiment of the present application; Figure 2 is a top view of a single cell according to an embodiment of the present application; Figure 3 is Figure 2 the A-A cross-sectional view of Figure 4 is Figure 2 the B-B cross-sectional view of Figure 5 and Figure 6 is Figure 4 the enlarged view of part C of Figure 7 is a schematic structural diagram of a sealing plate according to an embodiment of the present application; Figure 8 is a cross-sectional view of a sealing plate according to an embodiment of the present application; Figure 9 is a schematic structural diagram of a pole column before stamping according to an embodiment of the present application; Figure 10 is a schematic structural diagram of a pole column after stamping according to an embodiment of the present application; Figure 11 is a cross-sectional view of a pole column after stamping according to an embodiment of the present application.

[0046] Referring to Figures 1 to 11 , the single cell of the embodiment of the present application includes a housing 1, an electrode assembly 2, a cover plate assembly 3, and a sealing plate 4. The housing 1 has a receiving cavity 10; the electrode assembly 2 is located in the receiving cavity 10, and the electrode assembly 2 includes a pole group 20 and a pole ear 21; the cover plate assembly 3 includes a cover plate body 30 and a pole column 31. The cover plate body 30 is connected to the housing 1 and seals the receiving cavity 10. The cover plate body 30 has a pole column hole 300, and the pole column 31 passes through the pole column hole 300. The pole column 31 has a groove body 310, and the groove body 310 penetrates the pole column 31 along the thickness direction X of the cover plate body 30; the pole column 31 includes a pole column body 311 and a first riveting part 312. The first riveting part 312 is located on the side of the pole column body 311 away from the electrode assembly 2 and is connected to the pole column body 311. The first riveting part 312 has a first counterbore 3120, and the first counterbore 3120 is located on the side of the first riveting part 312 away from the electrode assembly 2; at least part of the sealing plate 4 is located in the first counterbore 3120 of the first riveting part 312 and seals the groove body 310, and the pole ear 21 passes through the groove body 310 and is connected to the sealing plate 4. By providing the groove body 310 on the pole column 31, the present application can reduce the weight of the pole column 31, arrange the sealing plate 4 in the first counterbore 3120 of the first riveting part 312 to seal the groove body 310, and pass the pole ear 21 through the groove body 310 and connect it to the sealing plate 4 to realize the electrical connection between the pole ear 21 and the pole column 31, which can prevent sundries from entering the groove body 310, realize the lightweight of the single cell, and improve the safety and stability of the single cell.

[0047] In some embodiments, referring to Figure 6 and Figure 7 , the sealing plate 4 includes a connected first sealing portion 40 and a second sealing portion 41. The first sealing portion 40 is located within the first sinking platform 3120, and the second sealing portion 41 is located on the side of the first sealing portion 40 close to the electrode assembly 2 and is spaced from the pole column body 311. The first sealing portion 40 is located within the first sinking platform 3120, and the connection between the first sealing portion 40 and the second sealing portion 41 is achieved by laser welding, so as to cover and seal the tank body 310. On the one hand, the space occupied by the sealing plate 4 in the thickness direction X can be effectively reduced, and the connection stability between the sealing plate 4 and the pole column 31 can be improved; on the other hand, sundries, moisture, etc. can be prevented from entering the interior of the tank body 310, thereby preventing adverse effects on the electrical connection between the pole lug 21 and the sealing plate 4, and improving the safety and reliability of the single cell.

[0048] In some embodiments, referring to Figure 5 , along the width direction Y of the cover plate body 30, the distance between the second sealing portion 41 and the pole column body 311 is G mm, satisfying: 0.02 ≤ G ≤ 0.1. Exemplarily, the distance G between the second sealing portion 41 and the pole column body 311 can be any value among 0.02, 0.04, 0.06, 0.08, 0.1 or the range value between two values. The side of the first sealing portion 40 away from the second sealing portion 41 is generally connected to the bus bar. The second sealing portion 41 penetrates into the tank body 310, and there is a certain gap between the second sealing portion 41 and the pole column body 311, which can ensure that the sealing plate 4 can be smoothly inserted into the tank body 310 during the assembly process, and at the same time avoid the assembly difficulty caused by too small a gap or the laser penetrating the sealing plate 4 when the sealing plate 4 is welded to the bus bar due to too large a gap, affecting the performance of the single cell. By limiting the distance between the second sealing portion 41 and the pole column body 311 in the embodiments of the present application, it is convenient to improve the assembly efficiency of the sealing plate 4 and the pole column 31, prevent the laser from penetrating the sealing plate 4 when the sealing plate 4 is laser welded to the bus bar, ensure the welding strength between the sealing plate 4 and the bus bar and the connection strength between the sealing plate 4 and the pole column body 311, and improve the safety and reliability of the single cell.

[0049] In some embodiments, referring to Figure 5, along the thickness direction X, the maximum dimension of the sealing plate 4 is T mm, and the dimension of the first sealing portion 40 is T1 mm, satisfying: 0.15 ≤ T - T1 ≤ 1.5. The difference between the maximum dimension T of the sealing plate and the dimension T1 of the first sealing portion 40 in the thickness direction X is the dimension of the second sealing portion 41 along the thickness direction X. It can be understood that if the dimension of the second sealing portion 41 is too small, it may cause the laser to easily penetrate the sealing plate 4 during the welding process, affecting the welding strength and the performance of the single cell. If the dimension of the second sealing portion 41 is too large, it will occupy too much space in the thickness direction X, increasing the material cost of the sealing plate 4. By limiting the difference between the maximum dimension T of the sealing plate 4 and the dimension T1 of the first sealing portion 40 in the thickness direction X in the embodiments of the present application, while avoiding the space occupation, material waste, and cost increase caused by the over-large dimension of the second sealing portion 41, the structural strength, sealing performance, and welding strength of the second sealing portion 41 can be ensured, preventing the laser from penetrating the sealing plate 4 during the welding process, and improving the safety and reliability of the single cell.

[0050] In some embodiments, referring to Figure 5 , along the thickness direction X, the maximum dimension T of the sealing plate 4 satisfies: 2 ≤ T ≤ 3. Exemplarily, the maximum dimension T of the sealing plate 4 can be any value among 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3 or a range value between two values. It can be understood that if the thickness of the sealing plate 4 is insufficient, it may cause insufficient welding strength, and the laser is likely to penetrate the sealing plate 4, affecting the welding effect and the performance of the single cell. If the thickness of the sealing plate 4 is too large, it will occupy too much space in the thickness direction X, increasing the material cost. By limiting the maximum dimension T of the sealing plate 4 in the embodiments of the present application, while avoiding the space occupation, material waste, and cost increase caused by the over-large dimension of the sealing plate 4, the structural strength, sealing performance, and welding strength of the sealing plate 4 can be ensured, preventing the laser from penetrating the sealing plate 4 during the welding process, and improving the safety and reliability of the single cell.

[0051] In some embodiments, referring to Figure 5, along the thickness direction X, the dimension T1 of the first sealing portion 40 in the thickness direction X satisfies: 0.8 ≤ T1 ≤ 1.5, ensuring the strength of the sealing plate 4 after welding. Exemplarily, the dimension T1 of the first sealing portion 40 in the thickness direction X can be any value among 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5 or a range value between two values. It can be understood that if the thickness of the first sealing portion 40 is insufficient, it may lead to insufficient welding strength between the first sealing portion 40 and the first riveting portion 312, prone to welding defects and affecting the performance of the single cell. If the thickness of the first sealing portion 40 is too large, it will occupy too much space in the thickness direction X, increasing the material cost. By limiting the dimension of the first sealing portion 40 in the thickness direction X in the embodiments of the present application, it can be ensured that the first sealing portion 40 has sufficient structural stability after welding, while avoiding welding defects caused by insufficient thickness, thereby improving the welding strength and the safety and reliability of the single cell.

[0052] In some embodiments, by providing a plurality of single cells with different dimensions of G, T, and T1, and testing the plurality of single cells, the test results are shown in Table 1.

[0053] Table 1:

[0054]

[0055]

[0056] Referring to Embodiment 1, when the single cell satisfies 0.02 ≤ G ≤ 0.1, 2 ≤ T ≤ 3, 0.8 ≤ T1 ≤ 1.5, and 0.15 ≤ T - T1 ≤ 1.5, the verification results are that the sealing plate 4 is easy to assemble; the sealing plate 4 is easy to process and the cost is reasonable; the welding and sealing effect between the sealing plate 4 and the pole column 31 is excellent; the welding connection strength between the sealing plate 4 and the bus bar is high; the sealing plate 4 has relatively high strength. It can be understood that when the G value satisfies 0.02 ≤ G ≤ 0.1, there is enough clearance during assembly to avoid difficult assembly, and at the same time, the sealing performance will not be affected due to too large a clearance. When the T value and the T1 value satisfy 2 ≤ T ≤ 3, 0.8 ≤ T1 ≤ 1.5, and 0.15 ≤ T - T1 ≤ 1.5, the sealing plate 4 as a whole has sufficient thickness, which can not only ensure the welding strength but also avoid material waste due to excessive thickness. The first sealing portion 40 has sufficient thickness and high welding strength. The second sealing portion 41 has sufficient thickness, which can effectively prevent laser penetration and avoid material waste at the same time.

[0057] Referring to Embodiment 2, when the single cell satisfies 0.15 ≤ T - T1 ≤ 1.5, 2 ≤ T ≤ 3, 0.8 ≤ T1 ≤ 1.5, but does not satisfy 0.02 ≤ G ≤ 0.1, the verification results are as follows: The sealing plate 4 is easy to assemble; the sealing plate 4 is easy to process and has a low cost; the welding sealing effect between the sealing plate 4 and the pole column 31 is excellent; when the sealing plate 4 is welded to the bus bar, the laser is extremely easy to penetrate the sealing plate 4 and damage the electrode assembly 2, affecting the performance of the single cell; the sealing plate 4 has a high strength. It can be understood that when the G value is too large, the gap between the second sealing portion 41 and the pole column body 311 is too large, which may cause the laser to penetrate the sealing plate 4 when the sealing plate 4 is welded to the bus bar, affecting the performance of the single cell.

[0058] Referring to Embodiment 3, when the single cell satisfies 0.15 ≤ T - T1 ≤ 1.5, 2 ≤ T ≤ 3, 0.8 ≤ T1 ≤ 1.5, but does not satisfy 0.02 ≤ G ≤ 0.1, the verification results are as follows: The sealing plate 4 is difficult to assemble, affecting the production line performance; the sealing plate 4 is difficult to process and has a high cost; the welding sealing effect between the sealing plate 4 and the pole column 31 is excellent; the welding connection strength between the sealing plate 4 and the bus bar is high; the sealing plate 4 has a high strength. It can be understood that when the G value is too small, the gap between the second sealing portion 41 and the pole column body 311 is too small, which may cause difficult assembly and affect the production efficiency.

[0059] Referring to Embodiment 4, when the single cell satisfies 0.02 ≤ G ≤ 0.1, 0.8 ≤ T1 ≤ 1.5, but does not satisfy 0.15 ≤ T - T1 ≤ 1.5, 2 ≤ T ≤ 3, the verification results are as follows: The sealing plate 4 is easy to assemble; the sealing plate 4 is difficult to process and has a high cost; the welding sealing effect between the sealing plate 4 and the pole column 31 is excellent; the welding connection strength between the sealing plate 4 and the bus bar is high; the sealing plate 4 has a high strength. It can be understood that when the T value is too large, the sealing plate 4 may occupy too much space in the thickness direction X, increasing the material cost and processing difficulty of the sealing plate 4. The difference between the maximum dimension T of the sealing plate and the dimension T1 of the first sealing portion 40 in the thickness direction X is the dimension of the second sealing portion 41 along the thickness direction X. If the difference T - T1 is too large, that is, the thickness of the second sealing portion 41 is too large, it may cause the second sealing portion 41 to occupy too much space in the thickness direction X, increasing the material cost and processing difficulty of the second sealing portion 41.

[0060] Referring to Embodiment 5, when the single cell satisfies 0.02 ≤ G ≤ 0.1, 0.15 ≤ T - T1 ≤ 1.5, 0.8 ≤ T1 ≤ 1.5, but does not satisfy 2 ≤ T ≤ 3, the verification results are as follows: The sealing plate 4 is easy to assemble; the sealing plate 4 is easy to process and has an extremely low cost; the welding sealing effect between the sealing plate 4 and the pole column 31 is excellent; when the sealing plate 4 is welded to the bus bar, the laser is extremely easy to penetrate; the sealing plate 4 damages the electrode assembly 2; the sealing plate 4 has a low strength. It can be understood that when the T value is too small, the laser is likely to penetrate the sealing plate 4 during the welding process of the sealing plate 4 and the bus bar, affecting the welding strength and the performance of the single cell.

[0061] Referring to Reference Example 6, when the single cell satisfies 0.02 ≤ G ≤ 0.1, 2 ≤ T ≤ 3, 0.15 ≤ T - T1 ≤ 1.5, but does not satisfy 0.8 ≤ T1 ≤ 1.5, the verification results are as follows: The sealing plate 4 is easy to assemble; the sealing plate 4 is difficult to machine, and the cost is reasonable; the welding sealing effect between the sealing plate 4 and the terminal 31 is poor; the welding connection strength between the sealing plate 4 and the bus bar is high; the strength of the sealing plate 4 is low. It can be understood that if the value of T1 is too small, it may lead to insufficient welding strength between the first sealing portion 40 and the first riveting portion 312, prone to welding defects, and affecting the performance of the single cell.

[0062] Referring to Reference Example 7, when the single cell satisfies 0.02 ≤ G ≤ 0.1, 2 ≤ T ≤ 3, 0.15 ≤ T - T1 ≤ 1.5, but does not satisfy 0.8 ≤ T1 ≤ 1.5, the verification results are as follows: The sealing plate 4 is easy to assemble; the sealing plate 4 is easy to machine, and the cost is reasonable; the welding sealing effect between the sealing plate 4 and the terminal 31 is poor; the welding connection strength between the sealing plate 4 and the bus bar is high; the strength of the sealing plate 4 is high; the height of the sealing plate 4 occupies a large space, reducing the capacity of the single cell. It can be understood that if the value of T1 is too large, it may lead to occupying too much space in the thickness direction X, increasing the material cost, and then resulting in a low energy density of the single cell.

[0063] In some embodiments, referring to Figure 6 and Figure 8 , the first riveting portion 312 has a first mating surface 3121, the sealing plate 4 has a second mating surface 42, the first mating surface 3121 and the second mating surface 42 are disposed opposite to each other along the width direction Y, and the first mating surface 3121 and the second mating surface 42 are connected by welding. The first mating surface 3121 and the second mating surface 42 are in contact, and the first riveting portion 312 and the sealing plate 4 are connected by laser welding, so as to achieve the sealing between the terminal 31 and the sealing plate 4.

[0064] In some embodiments, referring to Figure 5 , the portion where the first mating surface 3121 and the second mating surface 42 are in contact with each other has a maximum dimension H mm along the thickness direction X, and the maximum dimension of the first counterbore 3120 along the thickness direction X is T2 mm, satisfying: 0.25 ≤ H / T2 ≤ 0.8. By limiting the ratio range of the maximum dimension H of the portion where the first mating surface 3121 and the second mating surface 42 are in contact with each other along the thickness direction X to the thickness of the first counterbore 3120, it is possible to ensure that the welding seam has sufficient penetration depth, thereby improving the welding strength and avoiding problems such as fracture and welding detachment caused by poor welding. At the same time, to avoid too large a penetration depth of the welding seam, which may lead to heat stress concentration, an increase in welding defects, and excessive penetration depth may also cause unnecessary material melting and energy consumption, increasing the welding cost and reducing the production efficiency.

[0065] In some embodiments, referring toFigure 11 , a first flanging and riveting portion 312 forms a first guiding portion 3122 between one end far from the electrode assembly 2 and a first mating surface 3121. By providing the first guiding portion 3122, a buffering and guiding effect can be achieved. When assembling the sealing plate 4, it can prevent the sealing plate 4 from being deformed due to external force collision, thereby avoiding poor sealing and affecting the safety and reliability of the single battery.

[0066] In some embodiments, referring to Figure 7 and Figure 8 , a second guiding portion 43 is formed between one end of the sealing plate 4 far from the electrode assembly 2 and a second mating surface 42. By providing the second guiding portion 43, a buffering and guiding effect can be achieved. When assembling the sealing plate 4, it can prevent the first flanging and riveting portion 312 from being deformed due to external force, thereby affecting the connection stability between the pole column 31 and the cover plate body 30. By providing the second guiding portion 43, it helps to maintain the close fit between the sealing plate 4 and the bottom wall of the first sinking platform 3120, ensuring the sealing performance of the single battery and improving the safety and reliability of the single battery.

[0067] In some embodiments, referring to Figure 7 and Figure 8 , a third guiding portion 44 is formed between the first sealing portion 40 and the second sealing portion 41; a fourth guiding portion 3123 is formed between the bottom wall of the first sinking platform 3120 and the pole column body 311; the third guiding portion 44 and the fourth guiding portion 3123 are arranged opposite to each other. The third guiding portion 44 and the fourth guiding portion 3123 can play a buffering and guiding role. Through the cooperation of the third guiding portion 44 and the fourth guiding portion 3123, it is convenient to realize the assembly between the sealing plate 4 and the pole column 31, and the assembly efficiency can be effectively improved.

[0068] In some embodiments, referring to Figure 9 and Figure 10 , the pole column 31 includes a second flanging and riveting portion 313. The second flanging and riveting portion 313 is located on one side of the pole column body 311 close to the electrode assembly 2 and is connected to the pole column body 311. The second flanging and riveting portion 313 and the pole column body 311 enclose a limiting groove 314; the single battery includes a connecting portion 5. The connecting portion 5 is located between the cover plate body 30 and the electrode assembly 2 and surrounds the second flanging and riveting portion 313. At least a part of the connecting portion 5 is embedded in the limiting groove 314. The second flanging and riveting portion 313 can clamp and fix the cover plate body 30, enhancing the connection stability between the pole column 31 and the cover plate body 30. The pole column 31 is formed by one-time stamping, with a simple structure, reducing complex production processes, lowering production costs, and improving assembly efficiency.

[0069] In some embodiments, referring to Figure 6, the single cell includes a seal 6, and the seal 6 includes a first seal section 60, a second seal section 61 and a third seal section 62. The first seal section 60 is disposed between the pole column body 311 and the cover plate body 30. The second seal section 61 is clamped between the cover plate body 30 and the connecting portion 5. The third seal section 62 is embedded in the limiting groove 314 and is clamped between the pole column body 311 and the connecting portion 5. The first seal section 60 is respectively connected to the second seal section 61 and the third seal section 62. It should be understood that the seal 6 can be T-shaped. The isolation between the pole column body 311 and the cover plate body 30 is achieved through the first seal section 60 to achieve the purpose of insulation. The sealing between the cover plate body 30 and the connecting portion 5 is achieved through the second seal section 61. The sealing between the pole column body 311 and the connecting portion 5 is achieved through the third seal section 62.

[0070] Correspondingly, an embodiment of the present application provides a battery pack, including the above single cell.

[0071] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0072] The above has introduced in detail a single cell and a battery pack provided by the embodiments of the present application, and specific examples are used to elaborate the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the technical solution and its core idea of the present application; those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A single cell battery, characterized in that: include: A housing having a receiving cavity; An electrode assembly, located in the accommodating cavity, the electrode assembly comprising an electrode group and an electrode ear; A cover plate assembly, comprising a cover plate body and a pole, wherein the cover plate body is connected to the shell and covers the accommodating cavity, the cover plate body has a pole hole, the pole is inserted into the pole hole, and the pole has a slot body, and the slot body penetrates the pole along the thickness direction of the cover plate body; the pole comprises a pole body and a first riveted portion, the first riveted portion is located at a side of the pole body away from the electrode assembly and connected to the pole body, the first riveted portion has a first sink, and the first sink is located at a side of the first riveted portion away from the electrode assembly; A sealing plate, at least a portion of which is located in the first sink and covers the trough body, and the pole lug is passed through the trough body and connected to the sealing plate.

2. The single cell according to claim 1, characterized in that: The sealing plate includes a first sealing portion and a second sealing portion connected to each other. The first sealing portion is located in the first sink, and the second sealing portion is located on a side of the first sealing portion close to the electrode assembly and is spaced apart from the pole body.

3. The single cell according to claim 2, characterized in that: Along the width direction (Y) of the cap body, the distance between the second sealing portion and the pole body is G mm; along the thickness direction, the maximum size of the sealing plate is T mm, the size of the first sealing portion along the thickness direction is T1 mm, and the single battery satisfies any one of the following characteristics: a) 0.02≤G≤0.1; b)2≤T≤3; c) 0.8≤T1≤1.5; d)0.15≤T-T1≤1.

5.

4. The single cell according to claim 1, characterized in that: The first riveted portion has a first mating surface, the sealing plate has a second mating surface, the first mating surface and the second mating surface are arranged opposite to each other along the width direction, and the first mating surface and the second mating surface are connected by welding.

5. The single cell according to claim 4, characterized in that: Along the thickness direction, the portion where the first mating surface and the second mating surface contact each other has a maximum dimension H mm along the thickness direction, and the maximum dimension of the first sink along the thickness direction is T2 mm, satisfying: 0.25≤H / T2≤0.

8.

6. The single cell according to claim 4, characterized in that: A first guide portion is formed between one end of the first riveted portion away from the electrode assembly and the first mating surface; and / or A second guide portion is formed between an end of the sealing plate away from and close to the electrode assembly and the second matching surface.

7. The single cell according to claim 2, characterized in that: A third guide portion is formed between the first sealing portion and the second sealing portion; A fourth guide portion is formed between the bottom wall of the first sink and the pole body; The third guide portion and the fourth guide portion are arranged opposite to each other.

8. The single cell according to claim 1, characterized in that: The pole comprises a second riveted portion, the second riveted portion is located on a side of the pole body close to the electrode assembly and connected to the pole body, and the second riveted portion and the pole body are surrounded to form a limiting groove; The single battery comprises a connecting portion, which is located between the cover plate body and the electrode assembly and surrounds the second riveted portion, and at least a portion of the connecting portion is embedded in the limiting groove.

9. The single cell according to claim 8, characterized in that: The single cell battery includes a seal, which includes a first sealing section, a second sealing section and a third sealing section. The first sealing section is arranged between the pole body and the cover body, the second sealing section is clamped between the cover body and the connecting portion, the third sealing section is embedded in the limiting groove and clamped between the pole body and the connecting portion, and the first sealing section connects the second sealing section and the third sealing section respectively.

10. A battery pack, characterized in that: The invention comprises a single cell according to any one of claims 1 to 9.

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