Single battery, battery pack and power utilization device

Abstract

The invention discloses a single battery, a battery pack and a power utilization device, and belongs to the technical field of batteries. Comprising a shell, an electrode assembly, a cover plate assembly, a connecting part and a sealing piece. The pole comprises a pole body and a first flanging and riveting part; the first flanging and riveting part is positioned on one side, close to the electrode assembly, of the pole body and is connected with the pole body; a limiting groove is defined by the first flanging and riveting part and the pole body; the connecting part is located between the cover plate body and the electrode assembly and surrounds the first flanging and riveting part, and at least part of the connecting part is embedded in the limiting groove; the sealing element comprises 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 plate body, the second sealing section is arranged between the cover plate body and the connecting part, and the third sealing section is embedded in the limiting groove and is arranged between the pole body and the connecting part. The cover plate body is clamped and fixed by the first flanging riveting part, the pole is formed by one-time punch forming, the assembly efficiency is high, and the sealing performance of the cover plate assembly can be effectively improved by arranging the sealing element.

Description

Technical Field

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

[0002] The cover plate assembly in a single battery is mainly assembled by parts such as a pole column, a cover plate body, and a sealing ring. However, currently, the structures of the parts in the cover plate assembly are complex, the pole column cannot be formed in one step, and secondary processing is required, resulting in low processing efficiency. Summary of the Invention

[0003] Object of the Invention: Embodiments of this application provide a single battery, a battery pack, and an electrical device, aiming to solve the technical problem that the pole column cannot be formed in one step and the processing efficiency is low.

[0004] Technical Solution: Embodiments of this application provide a single battery, including:

[0005] A housing having a receiving cavity;

[0006] An electrode assembly located in the receiving cavity;

[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 receiving cavity. The cover plate body has a pole column hole penetrating along the thickness direction of the cover plate body, and the pole column is inserted into the pole column hole. 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 close to the electrode assembly and is connected to the pole column body; a limiting groove is formed by enclosing the first riveting part and the pole column body;

[0008] A connecting part located between the cover plate body and the electrode assembly and surrounding the first riveting part, and at least part of the connecting part is embedded in the limiting groove;

[0009] A seal including a first seal section, a second seal section, and a third seal section. The first seal section is disposed between the pole column body and the cover plate body, the second seal section is clamped between the cover plate body and the connecting part, the third seal section is embedded in the limiting groove and clamped between the pole column body and the connecting part, and the first seal section is connected to the second seal section and the third seal section respectively.

[0010] In some embodiments, along the thickness direction, the maximum dimension of the second seal section or the third seal section in the uncompressed state is H mm, and the maximum dimension of the second seal section or the third seal section in the compressed state is H1 mm, satisfying: 0.25 ≤ (H - H1) / H ≤ 0.45.

[0011] In some embodiments, the single battery satisfies any one of the following characteristics:

[0012] a) 0.8 ≤ H ≤ 1.1;

[0013] b) 0.6 ≤ H1 ≤ 0.8.

[0014] In some embodiments, along a direction intersecting with the thickness direction, the first sealing section has a first dimension W1 mm in an uncompressed state, there is a second dimension W2 mm between the side of the second sealing section away from the terminal post and the side of the cover plate body close to the terminal post, the third sealing section has a third dimension W3 mm in an uncompressed state, and the single cell satisfies any one of the following characteristics:

[0015] c) 0.5 ≤ W1 ≤ 0.75;

[0016] d) 1.1 ≤ W2 ≤ 1.5;

[0017] e) 0.8 ≤ W3 ≤ 1.2;

[0018] f) W3 ≤ W2.

[0019] In some embodiments, along a direction intersecting with the thickness direction, the distance between the side of the second sealing section away from the third sealing section and the side of the connecting portion away from the first riveting portion is L mm, satisfying: 0.5 ≤ L ≤ 1.8.

[0020] In some embodiments, the first riveting portion includes a supporting portion and a protruding portion. The supporting portion extends along the thickness direction and is connected to the terminal post body and the protruding portion respectively. The protruding portion protrudes from the supporting portion toward the side close to the connecting portion;

[0021] The protruding portion has a first mating surface, the connecting portion has a second mating surface disposed opposite to the first mating surface, and the first mating surface and the second mating surface are inclined with respect to the thickness direction.

[0022] In some embodiments, the terminal post has a groove body, and the groove body penetrates the terminal post along the thickness direction;

[0023] The single cell includes a sealing portion, and the sealing portion is connected to the terminal post body and seals the groove body;

[0024] The electrode assembly includes a pole group and a tab connected to each other, and the tab penetrates through the groove body and is connected to the sealing portion.

[0025] In some embodiments, the terminal post includes a second riveting portion, and the second riveting portion is located on the side of the terminal post body away from the electrode assembly and is connected to the terminal post body;

[0026] The second riveting portion has a counterbore, and the counterbore is located on the side of the second riveting portion away from the electrode assembly, and at least a part of the sealing portion is located in the counterbore.

[0027] Correspondingly, an embodiment of the present application provides a battery pack, including the above-mentioned single cell.

[0028] Correspondingly, an embodiment of the present application provides an electrical device, including the above-mentioned single cell or the above-mentioned battery pack.

[0029] Beneficial effects: The single cell of the embodiment of the present application includes a housing, an electrode assembly, a cover plate assembly, a connecting portion, and a seal. The housing has a receiving cavity; the electrode assembly is located in the receiving cavity; 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 penetrating along the thickness direction of the cover plate body, and the pole column is inserted through the pole column hole. The pole column includes a pole column body and a first riveting portion. The first riveting portion is located on the side of the pole column body close to the electrode assembly and is connected to the pole column body; a limiting groove is formed by enclosing the first riveting portion and the pole column body; the connecting portion is located between the cover plate body and the electrode assembly and surrounds the first riveting portion, and at least part of the connecting portion is embedded in the limiting groove; the seal includes a first seal section, a second seal section, and a third seal section. The first seal section is arranged between the pole column body and the cover plate body, the second seal section is clamped between the cover plate body and the connecting portion, and the third seal section is embedded in the limiting groove and clamped between the pole column body and the connecting portion. The first seal section is respectively connected to the second seal section and the third seal section. The first riveting portion can clamp and fix the cover plate body. The pole column is formed by one-time stamping, with a simple structure and high assembly efficiency. In addition, insulation is achieved through the first seal section between the pole column body and the cover plate body, sealing between the cover plate body and the connecting portion is achieved through the second seal section, and sealing between the pole column body and the connecting portion is achieved through the third seal section, thereby effectively improving the sealing performance of the cover plate assembly.

[0030] 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.

[0031] The electrical device of the embodiment of the present application includes the above-mentioned single cell, so the electrical device can have all the technical features and beneficial effects of the above-mentioned single cell or the above-mentioned battery pack, which will not be elaborated here. Description of the Drawings

[0032] 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 description in the embodiments. Obviously, the following drawings 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.

[0033] Figure 1 It is a schematic structural diagram of a single cell according to an embodiment of the present application;

[0034] Figure 2 It is a top view of a single cell according to an embodiment of the present application;

[0035] Figure 3 is Figure 2 the A-A cross-sectional view of

[0036] Figure 4 is Figure 2 the B-B cross-sectional view of

[0037] Figure 5 and Figure 6 is Figure 4 the enlarged view of part C of

[0038] Figure 7 the cross-sectional view of a cover plate assembly according to an embodiment of the present application;

[0039] Figure 8 the structural schematic diagram of a seal according to an embodiment of the present application;

[0040] Figure 9 the cross-sectional view of a seal according to an embodiment of the present application;

[0041] Figure 10 the structural schematic diagram of a pole column before stamping according to an embodiment of the present application;

[0042] Figure 11 the structural schematic diagram of a pole column after stamping according to an embodiment of the present application;

[0043] Figure 12 the cross-sectional view of a pole column after stamping according to an embodiment of the present application.

[0044] Reference numerals: 1, housing; 2, electrode assembly; 3, cover plate assembly; 4, connecting portion; 5, seal; 6, sealing portion; 7, first insulating member; 10, accommodating cavity; 20, electrode group; 21, tab; 30, cover plate body; 31, pole column; 40, second mating surface; 50, first sealing section; 51, second sealing section; 52, third sealing section; 300, pole column hole; 310, pole column body; 311, first riveting portion; 312, limiting groove; 313, groove body; 314, second riveting portion; 3110, supporting portion; 3111, protruding portion; 3112, first mating surface; 3140, counterbore; X, thickness direction. Detailed implementation manners

[0045] 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 shall fall within the protection scope of the present application.

[0046] 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 construed 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 a range of 10° of being completely parallel, it is considered parallel.

[0047] The applicant notes that the cover plate assembly in the single cell is mainly assembled from parts such as the pole column, the cover plate body, the sealing ring, etc. However, currently, the structures of the parts in the cover plate assembly are complex, the pole column cannot be formed in one processing, and secondary processing is required, resulting in low processing efficiency.

[0048] In view of this, the single cell of the embodiment of the present application includes a housing, an electrode assembly, a cover plate assembly, a connecting portion, and a seal. The housing has a receiving cavity; the electrode assembly is located in the receiving cavity; 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 penetrating along the thickness direction of the cover plate body, and the pole column is inserted through the pole column hole. The pole column includes a pole column body and a first riveting portion. The first riveting portion is located on the side of the pole column body close to the electrode assembly and is connected to the pole column body; a limiting groove is formed by enclosing the first riveting portion and the pole column body; the connecting portion is located between the cover plate body and the electrode assembly and surrounds the first riveting portion, and at least part of the connecting portion is embedded in the limiting groove; the seal 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 portion, the third sealing section is embedded in the limiting groove and is clamped between the pole column body and the connecting portion, and the first sealing section is respectively connected to the second sealing section and the third sealing section. The first riveting portion can clamp and fix the cover plate body. The pole column is formed by one-time stamping, with a simple structure and high assembly efficiency. In addition, the isolation between the pole column body and the cover plate body is achieved through the first sealing section to achieve the purpose of insulation, the sealing between the cover plate body and the connecting portion is achieved through the second sealing section, and the sealing between the pole column body and the connecting portion is achieved through the third sealing section, thereby effectively improving the sealing performance of the cover plate assembly.

[0049] The following will describe in detail the single cell, battery pack, and electrical device of the present application with reference to the accompanying drawings. Without conflict, the features in the following embodiments and implementation manners can be combined with each other.

[0050] 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 cross-sectional view of a cover plate assembly according to an embodiment of the present application; Figure 8 is a schematic structural diagram of a seal according to an embodiment of the present application; Figure 9 is a cross-sectional view of a seal according to an embodiment of the present application; Figure 10 is a schematic structural diagram of a pole column before stamping according to an embodiment of the present application; Figure 11 is a schematic structural diagram of a pole column after stamping according to an embodiment of the present application; Figure 12 is a cross-sectional view of a pole column after stamping according to an embodiment of the present application.

[0051] Refer toFigures 1 to 12 , the single cell of the embodiment of the present application includes a housing 1, an electrode assembly 2, a cover plate assembly 3, a connecting portion 4, and a seal 5. The housing 1 has a receiving cavity 10; the electrode assembly 2 is located in the receiving cavity 10; the cover plate assembly 3 includes a cover plate body 30 and a pole post 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 post hole 300 penetrating along the thickness direction X of the cover plate body 30. The pole post 31 is disposed in the pole post hole 300. The pole post 31 includes a pole post body 310 and a first riveting portion 311. The first riveting portion 311 is located on the side of the pole post body 310 close to the electrode assembly 2 and is connected to the pole post body 310; a limiting groove 312 is formed by enclosing the first riveting portion 311 and the pole post body 310; the connecting portion 4 is located between the cover plate body 30 and the electrode assembly 2 and surrounds the first riveting portion 311. At least a part of the connecting portion 4 is embedded in the limiting groove 312; the seal 5 includes a first seal section 50, a second seal section 51, and a third seal section 52. The first seal section 50 is disposed between the pole post body 310 and the cover plate body 30. The second seal section 51 is clamped between the cover plate body 30 and the connecting portion 4. The third seal section 52 is embedded in the limiting groove 312 and is clamped between the pole post body 310 and the connecting portion 4. The first seal section 50 is respectively connected to the second seal section 51 and the third seal section 52. The first riveting portion 311 can clamp and fix the cover plate body 30. The pole post 31 is formed by one-time stamping, with a simple structure and high assembly efficiency. In addition, the isolation between the pole post body 310 and the cover plate body 30 is achieved through the first seal section 50 to achieve the purpose of insulation. The sealing between the cover plate body 30 and the connecting portion 4 is achieved through the second seal section 51, and the sealing between the pole post body 310 and the connecting portion 4 is achieved through the third seal section 52, thereby effectively improving the sealing performance of the cover plate assembly 3.

[0052] In some embodiments, referring to Figure 6 , along the thickness direction X, the maximum dimension of the second seal section 51 or the third seal section 52 in the uncompressed state is H mm, and the maximum dimension of the second seal section 51 or the third seal section 52 in the compressed state is H1 mm, satisfying: 0.25 ≤ (H - H1) / H ≤ 0.45. It can be understood that by limiting the compression amount of the second seal section 51 or the third seal section 52 to be between 25% and 45%, the requirement for sealing the cover plate assembly 3 is achieved. Such a setting can avoid the influence of too small compression amount on the sealing effect, and can also avoid the increase in the risk of damage to the second seal section 51 or the third seal section 52 caused by too large compression amount, accelerating the aging of the second seal section 51 or the third seal section 52, and causing the safety problem of single cell leakage.

[0053] In some embodiments, referring to Figure 6, along the thickness direction X, the maximum dimension H of the second sealing section 51 or the third sealing section 52 in the uncompressed state satisfies: 0.8 ≤ H ≤ 1.1. Exemplarily, along the thickness direction X, the maximum dimension H of the second sealing section 51 or the third sealing section 52 in the uncompressed state can be any value among 0.8, 0.85, 0.9, 0.95, 1, 1.05, 1.1 or a range value between two values. With such a setting, while avoiding the second sealing section 51 or the third sealing section 52 occupying too much space in the thickness direction X, it ensures that the second sealing section 51 or the third sealing section 52 has a suitable initial thickness in the uncompressed state, so as to provide sufficient sealing performance during the subsequent compression process.

[0054] In some embodiments, referring to Figure 6 , the maximum dimension H1 of the second sealing section 51 or the third sealing section 52 in the compressed state satisfies: 0.6 ≤ H1 ≤ 0.8. Exemplarily, along the thickness direction X, the maximum dimension H1 of the second sealing section 51 or the third sealing section 52 in the compressed state can be any value among 0.6, 0.65, 0.7, 0.75, 0.8 or a range value between two values. With such a setting, it ensures that the second sealing section 51 or the third sealing section 52 can still maintain good sealing performance after compression, while avoiding damage or accelerated aging of the sealing material due to excessive compression. By limiting the size of the second sealing section 51 or the third sealing section 52 after compression to between 0.6 mm and 0.8 mm, it can ensure that the second sealing section 51 or the third sealing section 52 can effectively block the leakage of gas or liquid during actual use, and at the same time maintain sufficient elasticity and durability, thus ensuring the safety and reliability of the single cell.

[0055] In some embodiments, referring to Figure 6 and Figure 11 , along the direction intersecting with the thickness direction X, the first sealing section 50 has a first dimension W1 mm in the uncompressed state, satisfying: 0.5 ≤ W1 ≤ 0.75. Exemplarily, along the direction intersecting with the thickness direction X, the first dimension W1 of the first sealing section 50 in the uncompressed state can be any value among 0.5, 0.55, 0.6, 0.65, 0.7, 0.75 or a range value between two values. With such a setting, it ensures that during the riveting process, the first sealing section 50 can provide sufficient strength to achieve a firm connection between the terminal body 310 and the cover body 30, avoiding insufficient connection strength due to too small a size or increasing material costs and assembly difficulties due to too large a size.

[0056] In some embodiments, referring to Figure 6, along a direction intersecting with the thickness direction X, there is a second dimension W2 mm between the side of the second sealing section 51 away from the terminal 31 and the side of the cover plate body 30 close to the terminal 31, satisfying: 1.1 ≤ W2 ≤ 1.5. Exemplarily, the second dimension W2 between the side of the second sealing section 51 away from the terminal 31 and the side of the cover plate body 30 close to the terminal 31 can be any value among 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5 or a range value between two values. With such a setting, it is ensured that after the second sealing section 51 is compressed, there is sufficient lateral contact area between the second sealing section 51 and the cover plate body 30, thereby ensuring a good sealing effect, while avoiding sealing failure due to insufficient contact area or increasing material waste due to excessive contact area.

[0057] In some embodiments, along a direction intersecting with the thickness direction X, the third sealing section 52 has a third dimension W3 mm in the uncompressed state, satisfying: 0.8 ≤ W3 ≤ 1.2; Exemplarily, along a direction intersecting with the thickness direction X, the third dimension W3 of the third sealing section 52 in the uncompressed state can be any value among 0.8, 0.85, 0.9, 1, 1.05, 1.1, 1.15, 1.2 or a range value between two values. With such a setting, it is ensured that after the third sealing section 52 is compressed, there is sufficient lateral contact area between the third sealing section 52 and the terminal body 310 and the connecting portion 4, thereby achieving a reliable sealing effect, while avoiding sealing failure due to too small a dimension or affecting the assembly accuracy due to too large a dimension.

[0058] In some embodiments, the single cell satisfies: W3 ≤ W2. Based on the flow characteristics of the second sealing section 51 and the third sealing section 52. During the compression process, the third sealing section 52 cannot flow towards the direction of the terminal body 310, but will flow away from the direction of the terminal body 310. By ensuring W3 ≤ W2, it can be guaranteed that the third sealing section 52 can flow smoothly towards the second sealing section 51 after compression, ensuring the reliability of the seal 5 and the overall sealing performance, and avoiding the sealing failure problem caused by the poor flow of the seal 5.

[0059] In some embodiments, by setting different dimensions of H, H1, W1, W2, W3 and testing multiple single cells, the test results are shown in Table 1.

[0060]

[0061]

[0062] In some embodiments, the reasonable compression amount range of the seal 5 is confirmed through helium leak detection data. Exemplarily, a helium mass spectrometer is used to detect the helium leak rate. When the helium leak rate is less than 9.9x10-7 Pa.m 3 / s, the sealing requirement of the cover plate assembly 3 is met.

[0063] With reference to Examples 1 to 4, when the single cell meets the following conditions: 0.25≤(H-H1) / H≤0.45, 0.8≤H≤1.1, 0.6≤H1≤0.8, 0.5≤W1≤0.75, 1.1≤W2≤1.5, 0.8≤W3≤1.2, W3≤W2, the verification result is that the compression amount of the seal 5 is reasonable and there is no risk of failure; the pole 31 and the cover body 30 are well insulated; the connection part 4 and the cover body 30 have high sealing reliability; the connection part 4 and the pole 31 have high sealing reliability. It can be understood that by reasonably designing the size of the seal 5, ensuring a firm connection between the pole body 310 and the cover body 30, ensuring that the second sealing section 51 has sufficient lateral contact area with the cover body 30 after compression, ensuring that the third sealing section 52 can flow toward the second sealing section 51 after compression to avoid poor flow, thereby achieving a good sealing effect of the seal 5. By limiting the compression amount of the second sealing segment 51 or the third sealing segment 52 to between 25% and 45%, the sealing performance of the sealing element 5 can be effectively guaranteed, while avoiding sealing failure or material damage caused by excessive or insufficient compression.

[0064] Referring to Example 5, when the single cell satisfies 0.8≤H≤1.1, 1.1≤W2≤1.5, 0.8≤W3≤1.2, W3≤W2, but does not satisfy 0.25≤(H-H1) / H≤0.45, 0.6≤H1≤0.8, 0.5≤W1≤0.75, the verification result is that the seal 5 is over-compressed, the seal 5 is cracked, and the seal fails; the pole 31 and the cover body 30 fail, and there is a risk of short circuit; the sealing reliability of the connection part 4 and the cover body 30 is poor; the sealing reliability of the connection part 4 and the pole 31 is poor. It can be understood that the W1 value is too small, which may lead to insufficient riveting strength, the compression amount of the second sealing section 51 or the third sealing section 52 is 55%, and the second sealing section 51 or the third sealing section 52 is over-compressed, which makes the seal 5 easy to crack, and then causes the seal between the pole 31, the connection part 4 and the cover body 30 to fail, and there is a risk of short circuit.

[0065] Referring to Example 6, when the single cell meets 0.6≤H1≤0.8, 0.5≤W1≤0.75, 1.1≤W2≤1.5, 0.8≤W3≤1.2, but does not meet 0.25≤(H-H1) / H≤0.45, 0.8≤H≤1.1, W3≤W2, the verification result is that the compression of the seal 5 is insufficient, the seal fails, and the single cell leaks; the seal 5 between the pole 31 and the cover body 30 is fractured, and the insulation fails; the sealing reliability of the connection part 4 and the cover body 30 is poor; the sealing reliability of the connection part 4 and the pole 31 is poor. It can be understood that a large W1 value may lead to excessive riveting strength; the compression of the second sealing section 51 or the third sealing section 52 is insufficient, resulting in a decrease in sealing performance, which cannot meet the safety requirements of the single cell.

[0066] Referring to Example 7, when the single cell satisfies 0.6≤H1≤0.8, 0.5≤W1≤0.75, 1.1≤W2≤1.5, 0.8≤W3≤1.2, but does not satisfy 0.25≤(H-H1) / H≤0.45, 0.8≤H≤1.1, W3≤W2, the verification results are that the compression amount of the seal 5 is insufficient, the seal fails, and the single cell leaks; the pole 31 is well insulated from the cover body 30; the sealing reliability of the connection part 4 and the cover body 30 is poor; the sealing reliability of the connection part 4 and the pole 31 is poor. It is understandable that the H value is too small, resulting in insufficient initial thickness of the second sealing segment 51 or the third sealing segment 52 in the uncompressed state. The compression amount of the second sealing segment 51 or the third sealing segment 52 is 14%. The compression amount of the second sealing segment 51 or the third sealing segment 52 is insufficient, resulting in a decrease in sealing performance and failure to meet the safety requirements of the single cell battery; W3>W2, during the compression process, the third sealing segment 52 does not flow smoothly in the direction away from the pole body 310, which may cause the sealing failure problem between the connecting portion 4 and the pole 31.

[0067] Referring to Example 8, when the single cell meets 0.6≤H1≤0.8, 0.5≤W1≤0.75, 1.1≤W2≤1.5, 0.8≤W3≤1.2, W3≤W2, but does not meet 0.25≤(H-H1) / H≤0.45, 0.8≤H≤1.1, the verification result is that the compression of the seal 5 is insufficient, the seal fails, and the single cell leaks; the pole 31 and the cover body 30 are well insulated; the sealing reliability of the connection part 4 and the cover body 30 is poor; the sealing reliability of the connection part 4 and the pole 31 is poor. It can be understood that the H value is less than the H1 value, so that the compression of the second sealing section 51 or the third sealing section 52 is -14%, which proves that it is not only not compressed during the assembly process, but may be stretched or the expected deformation does not occur, so that the seal 5 cannot provide the necessary sealing performance, thereby causing the sealing failure.

[0068] Referring to Reference Example 9, when the single cell satisfies 0.6 ≤ H1 ≤ 0.8, 0.5 ≤ W1 ≤ 0.75, W3 ≤ W2, but does not satisfy 0.25 ≤ (H - H1) / H ≤ 0.45, 0.8 ≤ H ≤ 1.1, 1.1 ≤ W2 ≤ 1.5, 0.8 ≤ W3 ≤ 1.2, the verification result is that the seal 5 is over-compressed, the seal 5 is cracked, and the seal fails; the pole 31 is well insulated from the cover body 30; the sealing reliability between the connecting portion 4 and the cover body 30 is poor; the sealing reliability between the connecting portion 4 and the pole 31 is poor. It can be understood that a larger H value may cause the seal 5 to bear greater stress during compression, increasing the risk of material cracking. The compression amount of the second sealing section 51 or the third sealing section 52 is 50%, and a too large compression amount may cause damage or accelerated aging of the sealing material, resulting in a safety problem of leakage of the single cell. A smaller W2 value results in insufficient lateral contact area between the second sealing section 51 and the cover body 30, which may lead to a decrease in the sealing reliability between the connecting portion 4 and the cover body 30. A smaller W3 value results in insufficient lateral contact area between the third sealing section 52 and the pole body 310 and the connecting portion 4, which may lead to a decrease in the sealing reliability between the connecting portion 4 and the pole 31.

[0069] In some embodiments, referring to Figure 7 , along a direction intersecting with the thickness direction X, the distance between the side of the second sealing section 51 away from the third sealing section 52 and the side of the connecting portion 4 away from the first riveting portion 311 is L mm, satisfying: 0.5 ≤ L ≤ 1.8. Exemplarily, the distance L between the side of the second sealing section 51 away from the third sealing section 52 and the side of the connecting portion 4 away from the first riveting portion 311 can be any value among 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8 or a range value between two values. Referring to Figure 6 , the single cell includes a first insulating member 7, the first insulating member 7 is located on the side of the cover body 30 close to the electrode assembly 2, the connecting portion 4 is located between the first insulating member 7 and the cover body 30, and by defining the distance L between the side of the second sealing section 51 away from the third sealing section 52 and the side of the connecting portion 4 away from the first riveting portion 311, it can ensure that there is sufficient contact distance between the first insulating member 7 and the connecting portion 4, and ensure the positioning effect of the first insulating member 7 on the cover body 30.

[0070] In some embodiments, referring to Figure 12, the first clinching part 311 includes a supporting part 3110 and a protruding part 3111. The supporting part 3110 extends along the thickness direction X and is respectively connected to the pole column body 310 and the protruding part 3111. The protruding part 3111 protrudes from the supporting part 3110 toward the side close to the connecting part 4. The protruding part 3111 has a first mating surface 3112, and the connecting part 4 has a second mating surface 40 disposed opposite to the first mating surface 3112. The first mating surface 3112 and the second mating surface 40 are inclined with respect to the thickness direction X. Through the inclined protruding part 3111 and the connecting part 4, on the one hand, the contact area between the connecting part 4 and the protruding part 3111 is increased, so that stress can be dispersed. While reducing the space occupation of the connecting part 4 and the pole column 31 in the thickness direction X, the connection stability between the connecting part 4 and the pole column 31 is effectively improved, ensuring the connection strength. On the other hand, by using the gravity of the connecting part 4, a self-locking function can be realized to prevent the connecting part 4 from accidentally slipping out.

[0071] In some embodiments, referring to Figures 10 to 12 , the pole column 31 has a groove 313, and the groove 313 penetrates the pole column 31 along the thickness direction X. The single cell includes a sealing part 6, and the sealing part 6 is connected to the pole column body 310 and seals the groove 313. The electrode assembly 2 includes a pole group 20 and a tab 21 connected to each other. The tab 21 passes through the groove 313 and is connected to the sealing part 6. By providing the groove 313 on the pole column 31 in this application, the weight of the pole column 31 can be reduced. By sealing the groove 313 with the sealing part 6, passing the tab 21 through the groove 313 and connecting it to the sealing part 6, an effective electrical connection between the tab 21 and the pole column 31 can be achieved, preventing foreign objects from entering the groove 313 and preventing faults such as short circuits caused by foreign objects, realizing the lightweight of the single cell, and improving the safety and stability of the single cell.

[0072] In some embodiments, referring to Figure 5 , the pole column 31 includes a second clinching part 314, and the second clinching part 314 is located on the side of the pole column body 310 away from the electrode assembly 2 and is connected to the pole column body 310. By providing the second clinching part 314 to be connected to the sealing part 6, the precise positioning of the sealing part 6 can be ensured, and the sealing effect on the groove 313 can be ensured.

[0073] In some embodiments, referring to Figure 5, the second flanging and riveting portion 314 has a counterbore 3140, the counterbore 3140 is located on the side of the second flanging and riveting portion 314 away from the electrode assembly 2, and at least part of the sealing portion 6 is located within the counterbore 3140. The sealing portion 6 is embedded in the counterbore 3140 and connected by welding. On the one hand, the space occupation in the thickness direction X can be effectively reduced, and the connection stability between the sealing portion 6 and the pole column 31 can be improved; on the other hand, sundries, moisture, etc. can be prevented from entering the inside of the tank body 313, thereby preventing adverse effects on the electrical connection between the pole ear 21 and the sealing portion 6, and improving the safety and reliability of the single cell.

[0074] Correspondingly, an embodiment of the present application provides a battery pack, including the above-mentioned single cell. Therefore, the battery pack can have all the technical features and beneficial effects of the above-mentioned single cell, which will not be elaborated here.

[0075] Correspondingly, an embodiment of the present application provides an electrical device, including the above-mentioned single cell, or the above-mentioned battery pack. Therefore, the electrical device can have all the technical features and beneficial effects of the above-mentioned single cell or the above-mentioned battery pack, which will not be elaborated here. The electrical device can be a mobile phone, a portable device, a laptop computer, a battery car, an electric vehicle, a ship, a spacecraft, an electric toy, and an electric tool, etc. For example, spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc.; electric toys include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc.

[0076] In the above embodiments, the descriptions of the respective embodiments have their own focuses. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0077] The above has introduced in detail a single cell, a battery pack, and an electrical device provided by the embodiments of the present application, and specific examples have been 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 for 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; 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 penetrating along the thickness direction of the cover plate body, the pole is inserted into the pole hole, the pole comprises a pole body and a first riveted portion, the first riveted portion is located on a side of the pole body close to the electrode assembly and connected to the pole body; the first riveted portion and the pole body are enclosed to form a limiting groove; A connecting portion, located between the cover plate body and the electrode assembly and surrounding the first riveted portion, wherein at least a portion of the connecting portion is embedded in the limiting groove; The sealing member includes a first sealing segment, a second sealing segment and a third sealing segment, wherein the first sealing segment is arranged between the pole body and the cover body, the second sealing segment is clamped between the cover body and the connecting portion, the third sealing segment is embedded in the limiting groove and clamped between the pole body and the connecting portion, and the first sealing segment connects the second sealing segment and the third sealing segment respectively.

2. The single cell according to claim 1, characterized in that: Along the thickness direction, the maximum dimension of the second sealing segment or the third sealing segment in an uncompressed state is H mm, and the maximum dimension of the second sealing segment or the third sealing segment in a compressed state is H1 mm, satisfying: 0.25≤(H-H1) / H≤0.

45.

3. The single cell according to claim 2, characterized in that: The single cell meets any one of the following characteristics: a) 0.8 ≤ H ≤ 1.1; b)0.6≤H1≤0.

8.

4. The single cell according to claim 1, characterized in that: Along the direction intersecting the thickness direction, the first sealing section has a first size W1 mm ​​in an uncompressed state, the second sealing section has a second size W2 mm between a side away from the pole and a side of the cover body close to the pole, and the third sealing section has a third size W3 mm in an uncompressed state, and the single battery satisfies any one of the following characteristics: c) 0.5≤W1≤0.75; d) 1.1≤W2≤1.5; e) 0.8 ≤ W3 ≤ 1.2; f)W3≤W2.

5. The single cell according to claim 1, characterized in that: Along the direction intersecting the thickness direction, a distance between a side of the second sealing segment away from the third sealing segment and a side of the connecting portion away from the first riveted portion is L mm, satisfying: 0.5≤L≤1.

8.

6. The single cell according to claim 1, characterized in that: The first riveted portion includes a supporting portion and a protruding portion, the supporting portion extends along the thickness direction and is connected to the pole body and the protruding portion respectively, and the protruding portion protrudes from the supporting portion toward a side close to the connecting portion; The protruding portion has a first mating surface, and the connecting portion has a second mating surface arranged opposite to the first mating surface. The first mating surface and the second mating surface are inclined relative to the thickness direction.

7. The single cell according to claim 1, characterized in that: The pole has a slot body, and the slot body penetrates the pole along the thickness direction; The single cell comprises a sealing portion, which is connected to the pole body and covers the tank body; The electrode assembly comprises a connected electrode group and an electrode tab, wherein the electrode tab is passed through the slot body and connected to the sealing portion.

8. The single cell according to claim 7, characterized in that: The pole comprises a second riveted portion, which is located at a side of the pole body away from the electrode assembly and connected to the pole body; The second riveted portion has a sinking platform, which is located at a side of the second riveted portion away from the electrode assembly, and at least a portion of the sealing portion is located in the sinking platform.

9. A battery pack, characterized in that: The invention comprises a single cell according to any one of claims 1 to 8.

10. An electrical device, characterized in that: The invention comprises a single cell as claimed in any one of claims 1 to 8, or a battery pack as claimed in claim 9.

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