Single battery and battery pack

Abstract

The invention discloses a single battery and a battery pack, and belongs to the technical field of batteries. Each single battery comprises a cover plate assembly and an electrode assembly, and the electrode assembly is arranged on one side of the cover plate assembly; the cover plate assembly comprises a cover plate body, a pole, a connecting block and a sealing plate; an assembly hole is formed in the cover plate body; a through hole is formed in the pole, the pole comprises a first connecting part, a main body part and a second connecting part, the main body part penetrates through the assembly hole, the first connecting part is arranged on the side, away from the electrode assembly, of the cover plate body and connected with the main body part, the second connecting part is arranged at the end, away from the first connecting part, of the main body part, and a limiting groove is defined by the second connecting part and the main body part; the connecting block is arranged on the side, away from the first connecting part, of the cover plate body, is partially embedded in the limiting groove and is connected with the second connecting part, and the cover plate body is clamped between the first connecting part and the connecting block; and the sealing plate covers and seals the through hole. The pole is formed by one-step processing and is light in weight, the production efficiency is improved, and the processing cost is reduced.

Description

Technical Field

[0001] The present application belongs to the field of battery technology, and specifically relates to a single cell and a battery pack. Background Art

[0002] The single cell comprises a shell, an electrode assembly and a cover assembly. The cover assembly is used to cover the shell, and the cover assembly carries a pole.

[0003] However, the poles in the cover plate assembly cannot be processed in one step and require secondary processing. Summary of the invention

[0004] Purpose of the invention: An embodiment of the present application provides a single cell battery, aiming to overcome the current technical problem of complex electrode processing; another purpose of the embodiment of the present application is to provide a battery pack.

[0005] Technical solution: The single cell disclosed in the embodiment of the present application comprises: a cover plate assembly and an electrode assembly, wherein the electrode assembly is arranged on one side of the cover plate assembly in the thickness direction thereof;

[0006] The cover plate assembly comprises:

[0007] The cover body is provided with an assembly hole along the thickness direction;

[0008] A pole having a through hole, the pole comprising a first connecting portion, a main body and a second connecting portion, the main body being inserted through the assembly hole, the first connecting portion being arranged at a side of the cover body away from the electrode assembly and connected to the main body, the second connecting portion being arranged at an end of the main body away from the first connecting portion, and the second connecting portion and the main body forming a limiting groove;

[0009] The through hole penetrates the first connecting portion, the main body portion and the second connecting portion along the thickness direction;

[0010] A connecting block is arranged on a side of the cover body away from the first connecting portion, is partially embedded in the limiting groove, and is connected to the second connecting portion, and the cover body is sandwiched between the first connecting portion and the connecting block;

[0011] A sealing plate covers the through hole.

[0012] In some embodiments, the second connecting portion is provided with a first riveting section protruding in a direction away from the through hole, for forming a limiting groove;

[0013] The connecting block is connected to the first riveting section.

[0014] In some embodiments, the connecting block includes a convex portion, the convex portion is convexly provided on a side of the connecting block facing the second connecting portion, the convex portion is embedded in the limiting groove, and abuts against the first riveting section.

[0015] In some embodiments, the first riveting section has a first step surface, and the first step surface is located on a side of the first riveting section away from the through hole;

[0016] The connecting block has a second step surface, and the second step surface is arranged opposite to the first step surface;

[0017] The cover plate assembly further includes a first welding portion, and the first welding portion connects the first step surface and the second step surface respectively.

[0018] In some embodiments, the first connecting portion is provided with a second riveted section protruding in a direction away from the cover plate body, and the second riveted section surrounds and connects the sealing plate;

[0019] On a plane perpendicular to the thickness direction, the orthographic projection of the second riveting section is located outside the orthographic projection of the through hole;

[0020] The cover plate assembly further includes a second welding portion, and the second welding portion is respectively connected to the sealing plate and the second riveted section.

[0021] In some embodiments, on a plane perpendicular to the thickness direction, the main body has a radial width W mm, and the first connecting portion has a radial width W mm. 1 mm, the second connecting portion has a radial width W 2 mm, the second riveted section has a radial width W 3 mm, the first riveted section has a radial width W 4 mm, meeting the following requirements: 1.8≤W≤2.5, 3.0≤W 1 ≤4.2,1.0≤W 2 ≤1.5, 1.0≤W 3 ≤1.5,0.15≤W 4 ≤0.75;

[0022] And / or, along the thickness direction, the first connecting portion has a thickness dimension L 1 mm, the second connecting portion has a thickness dimension L 2 mm, the first riveted section has a thickness dimension L 3 mm, the second riveted section has a thickness dimension L 6 mm, satisfying: 1.5≤L 1 ≤2.0,1.15≤L 2 ≤2.1,0.35≤L3 ≤0.6, 0.6≤L 6 ≤1.5;

[0023] And / or, the convex portion has a thickness dimension L 4 mm, the connection block has a thickness dimension L 5 mm, satisfying: 0.2≤L 4 ≤0.8,0.65≤L 5 ≤1.5.

[0024] In some embodiments, the sealing plate includes a first portion and a second portion connected to each other, the first portion is inserted into the through hole, and the second portion is located on a side of the first portion away from the electrode assembly and supported on a side of the first connecting portion away from the main body;

[0025] Along the thickness direction, the sealing plate has a portion protruding from the second riveted section, and along the thickness direction, the protruding portion has a thickness dimension D 1 mm, satisfying: 0.05≤D 1 ≤0.2.

[0026] In some embodiments, the cover assembly also 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 main body and the cover body, the second sealing section is clamped between the cover body and the connecting block, the third sealing section is embedded in the limiting groove and clamped between the main body and the connecting block, and the first sealing section connects the second sealing section and the third sealing section respectively.

[0027] In some embodiments, a sink groove is formed on one side of the cover body facing the connection block, and the sink groove is connected to the assembly hole and the limiting groove;

[0028] The sink has a first wall facing the connection block, and the main body has a second wall facing the connection block. The first wall and the second wall are on the same plane perpendicular to the thickness direction.

[0029] In some embodiments, the electrode assembly includes a tab, and the tab passes through the through hole and is connected to the sealing plate.

[0030] The embodiment of the present application also discloses a battery pack, comprising the single cell battery as described in the above embodiment.

[0031] Beneficial effects: In the single battery of the embodiment of the present application, the structure of the pole column includes a first connection part, a main body part and a second connection part. The through hole formed in the pole column penetrates the first connection part, the main body part and the second connection part along the thickness direction. Through the above structural design, during the processing of the pole column, it can be processed in one go without complex secondary processing techniques, greatly improving production efficiency and reducing processing costs and time costs. At the same time, the inside of the pole column is not solid material, but by forming a through hole, on the premise of ensuring the structural strength and electrical conductivity of the pole column, the weight of the component is effectively reduced and the cost is lowered. By setting that the connection block is partially embedded in the limit groove and connected to the second connection part, and at the same time the cover plate body is clamped between the first connection part and the connection block, the connection stability between the components is increased. During the use of the battery, it can effectively avoid performance degradation and failure problems caused by component loosening, and improve the reliability and service life of the battery.

[0032] The battery pack of the embodiment of the present application includes the single battery as described in the above embodiment. Therefore, it can have all the technical features and technical effects of the above single battery, which will not be elaborated here. Description of the Drawings

[0033] 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 following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained according to these drawings.

[0034] Figure 1 It is a three-dimensional structure schematic diagram of the single battery of the embodiment of the present application;

[0035] Figure 2 It is a top view structure schematic diagram of the single battery of the embodiment of the present application;

[0036] Figure 3 It is an assembly structure schematic diagram of the cover plate body and the pole column in the single battery of the embodiment of the present application;

[0037] Figure 4 It is Figure 2 The sectional structure schematic diagram along the A-A direction in;

[0038] Figure 5 It is Figure 4 The partial enlarged schematic diagram at C in;

[0039] Figure 6 It is Figure 2 The sectional structure schematic diagram along the B-B direction in;

[0040] Figure 7 It is Figure 6Partial enlarged schematic view at D in the [Chinese context];

[0041] Figure 8 Semi-sectional structure schematic view of the terminal post in the single cell of the embodiment of the present application;

[0042] Figure 9 Semi-sectional structure schematic view of the connecting block in the single cell of the embodiment of the present application;

[0043] Explanation of reference numerals: 1. Cover plate assembly; 2. Electrode assembly; X. Thickness direction; 11. Cover plate body; 110. Assembly hole; 12. Terminal post; 120. Through hole; 121. First connection part; 122. Main body part; 123. Second connection part; 124. Limiting groove; 13. Sealing plate; 14. Connecting block; 125. First riveting section; 141. Convex part; 1251. First step surface; 1411. Second step surface; 15. First welding part; 126. Second riveting section; 16. Second welding part; 131. First part; 132. Second part; 17. Sealing member; 171. First sealing section; 172. Second sealing section; 173. Third sealing section; 111. Sunk groove; 1111. First wall; 1221. Second wall; 21. Tab. Detailed implementation manners

[0044] 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 making creative efforts belong to the scope of protection of the present application.

[0045] In the description of the present application, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "inner", "outer", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present application. In the description of the present application, "a plurality of" means two or more, and at least one means it can be one, two or more, unless otherwise clearly and specifically defined. Terms such as "first", "second", "third", etc. are only used for naming parts or embodiments by numbers for the convenience of description, and do not imply an important ranking between the parts or between the embodiments.

[0046] It should also be noted that in the accompanying drawings of the specification of the present application, an arrow marked with X indicates the thickness direction. In the description of the present application, introducing the thickness direction X is to more clearly define the structure and relative positional relationship of each component in the single cell.

[0047] As the preamble of the embodiment of the present application, the cover plate assembly 1 in the battery is mainly composed of a pole 12, a cover plate body 11 and a sealing ring assembly. However, the pole 12 in the cover plate assembly 1 cannot be processed in one step and requires secondary processing. In addition, the inside of the pole 12 is solid material, the parts are heavy, the cost is high, and the competitiveness is reduced.

[0048] In view of this, an embodiment of the present application provides a single cell battery, aiming to solve at least one of the above-mentioned technical problems.

[0049] See also Figures 1 to 9 As shown, the single cell of the embodiment of the present application includes: a cover plate assembly 1 and an electrode assembly 2, wherein the electrode assembly 2 is arranged on one side of the cover plate assembly 1 in the thickness direction X thereof; the single cell also includes a shell for accommodating the electrode assembly 2 and providing mechanical support to prevent the electrode assembly 2 from being corroded and damaged by the external environment and being damaged by external extrusion. The cover plate assembly 1 includes: a cover plate body 11, a pole 12, a connecting block 14 and a sealing plate 13; the cover plate body 11 is provided with an assembly hole 110 along the thickness direction X; the pole 12 is provided with a through hole 120 along the thickness direction X, the pole 12 includes a first connecting portion 121, a main body 122 and a second connecting portion 123, the main body 122 is penetrated through the assembly hole 110, the first connecting portion 121 is provided on the side of the cover plate body 11 away from the electrode assembly 2 and connected to the main body 122, and the second connecting portion 123 is provided on the main body 122 At one end away from the first connection part 121, the second connection part 123 and the main body 122 form a limiting groove 124; the through hole 120 passes through the first connection part 121, the main body 122 and the second connection part 123 along the thickness direction X; the connecting block 14 is arranged on the side of the cover body 11 away from the first connection part 121, and is partially embedded in the limiting groove 124 and connected to the second connection part 123, and the cover body 11 is clamped between the first connection part 121 and the connecting block 14; the sealing plate 13 passes through and seals the through hole 120.

[0050] It should be understood that the structure of the pole 12 includes a first connecting portion 121, a main body 122 and a second connecting portion 123. The main body 122 passes through an assembly hole 110 of the cover body 11. The first connecting portion 121 is arranged on the side of the cover body 11 away from the electrode assembly 2 and connected to the main body 122. The second connecting portion 123 and the main body 122 form a limiting groove 124, so that the connecting block 14 is partially embedded in the limiting groove 124 and connected to the second connecting portion 123, and the cover body 11 is clamped between the first connecting portion 121 and the connecting block 14. This multiple connection and limiting method effectively enhances the tightness of the connection between the components, and can better resist the stress caused by factors such as thermal expansion and contraction or vibration during the charging and discharging process of the battery, thereby ensuring the long-term stable operation of the battery in a complex environment.

[0051] During the processing of the terminal post 12 of the present application, it can be processed in one go without complex secondary processing techniques, greatly improving production efficiency and reducing processing costs. The through hole 120 formed on the terminal post 12 penetrates through the first connection portion 121, the main body portion 122, and the second connection portion 123 along the thickness direction X. The interior of the terminal post 12 is not solid material. Instead, by forming the through hole 120, while ensuring the structural strength and electrical conductivity of the terminal post 12, the weight of the component is effectively reduced and the cost is lowered.

[0052] In some embodiments, the second connection portion 123 protrudes with a first riveting section 125 towards the direction away from the through hole 120 for enclosing a limiting groove 124; the connection block 14 is connected to the first riveting section 125. It should be understood that by riveting the first riveting section 125 and the connection block 14, the contact area and mechanical strength of the connection are increased. A tight connection can be formed between the first riveting section 125 and the connection block 14, and the stress is dispersed to prevent the connection part from loosening or falling off, ensuring the integrity of the internal structure of the battery, and thus maintaining the stability of the battery performance. During the assembly process, the first riveting section 125 can provide a clear positioning and guiding function to reduce the assembly difficulty and improve the assembly efficiency.

[0053] Please refer to Figures 5 to 9 As shown, in some embodiments, the connection block 14 includes a convex portion 141, which protrudes from the side of the connection block 14 towards the second connection portion 123. The convex portion 141 is embedded in the limiting groove 124 and abuts against the first riveting section 125. It should be understood that by arranging the convex portion 141 of the connection block 14 to be embedded in the limiting groove 124 and abut against the first riveting section 125, on the one hand, the displacement of the connection block 14 in the plane direction is restricted, and on the other hand, the external force in the vertical direction is resisted to a certain extent. When the battery is subjected to severe vibration and impact, the abutting connection block 14 and the second connection portion 123 can effectively prevent the connection block 14 from falling out of the limiting groove 124, enhancing the stability of the overall structure.

[0054] It should also be understood that by the connection block 14 abutting against the first riveting section 125, stress transfer and dispersion are achieved, effectively avoiding fatigue damage to the connection part caused by excessive local stress, ensuring the structural integrity and performance stability of the battery under complex working conditions, and extending the service life of the battery. The cooperation between the convex portion 141 and the first riveting section 125 makes it easier to align and fix the connection block 14 during installation. Just by buckling the convex portion 141 of the connection block 14 on the first riveting section 125, the preliminary positioning of the connection block 14 can be completed, greatly reducing the assembly difficulty. At the same time, this precise positioning method effectively reduces the quality problems caused by assembly errors and improves the qualified rate of the product.

[0055] It should also be noted that the tight abutment between the convex portion 141 and the first riveted section 125 ensures stable contact between the connecting block 14 and the pole 12. During the battery charging and discharging process, stable contact can effectively reduce contact resistance, reduce energy loss and heat generation, and significantly improve the battery charging and discharging efficiency and performance stability.

[0056] See also Figures 5 to 9 As shown, in some embodiments, the first riveted section 125 has a first step surface 1251, and the first step surface 1251 is located on the side of the first riveted section 125 away from the through hole 120; the connecting block 14 has a second step surface 1411, and the second step surface 1411 is arranged opposite to the first step surface 1251; the cover plate assembly 1 also includes a first welding portion 15, and the first welding portion 15 is respectively connected to the first step surface 1251 and the second step surface 1411. By the first step surface 1251 and the second step surface 1411 being arranged opposite to each other, the convex portion 141 and the first riveted section 125 are matched to each other, so that the connecting block 14 and the second connecting portion 123 form a more complex and stable connection structure, and the friction and mechanical bite force between the connecting block 14 and the first riveted section 125 are increased. When subjected to complex external forces, it can more effectively disperse and resist stress, and further improve the stability of the battery structure.

[0057] Specifically, the first step surface 1251 is connected to the second step surface 1411 through the first welding part 15, and the welding part can withstand large tensile and shear forces, preventing the connection block 14 and the first riveted section 125 from separating or loosening during long-term use. At the same time, the first welding part 15 can fill the gap between the first step surface 1251 and the second step surface 1411, improve the sealing performance, avoid contact between the electrolyte and the external environment, ensure the safety of the battery, and increase the service life. The first step surface 1251 and the second step surface 1411 are connected by the first welding part 15, eliminating the air gap or impurities that may exist in the connection part, so that the current can pass through the connection block 14 and the first riveted section 125 more smoothly, reducing the contact resistance, reducing the energy loss and heat generation during the charging and discharging process, and increasing the reliability of the electrical connection. During the long-term use of the battery, stable current transmission performance can be maintained.

[0058] See also Figure 5 , Figure 7 and Figure 8As shown, in some embodiments, the first connecting portion 121 protrudes with a second riveting section 126 in a direction away from the cover plate body 11, and the second riveting section 126 surrounds and connects the sealing plate 13; in a plane perpendicular to the thickness direction X, the orthographic projection of the second riveting section 126 is located outside the orthographic projection of the through hole 120; the cover plate assembly 1 further includes a second welding portion 16, and the second welding portion 16 connects the sealing plate 13 and the second riveting section 126 respectively. It should be understood that by arranging the second riveting section 126 to surround and connect the sealing plate 13, a tight and reliable sealed connection is formed between the sealing plate 13 and the pole 12 by riveting, effectively preventing electrolyte leakage, avoiding internal short circuit of the battery, and thus improving the safety and service life of the battery. At the same time, good sealing performance also helps to maintain the stability of the chemical environment inside the battery and ensure the consistency and stability of battery performance.

[0059] It should also be understood that by defining the projection relationship between the second riveting section 126 and the through hole 120, the connection structure between the pole 12 and the sealing plate 13 and the sealing path between the sealing plate 13 and the pole 12 are defined, improving the sealing level; at the same time, the second riveting section 126 can define the assembly path and assembly space of the sealing plate 13, so as to facilitate the positioning of the assembly position of the sealing plate 13, improving the assembly efficiency and at the same time improving the assembly stability of the sealing plate 13. By welding the sealing plate 13 and the second riveting section 126 with the second welding portion 16, the gap between the sealing plate 13 and the first riveting section 125 is filled to prevent electrolyte leakage from the through hole 120. On the basis of the first welding portion 15, adding the second welding portion 16 further strengthens the sealing structure of the battery to reduce the risk of electrolyte leakage. At the same time, the contact resistance that may exist between the sealing plate 13 and the pole 12 is eliminated, further reducing the overall resistance of the battery, reducing the energy loss and heat generation during the charge and discharge process. During the long-term charge and discharge process of the battery, a stable current transmission performance can be maintained.

[0060] Please refer to Figure 7 As shown, in some embodiments, in a plane perpendicular to the thickness direction X, the main body portion 122 has a radial width of W mm, the first connecting portion 121 has a radial width of W 1 mm, the second connecting portion 123 has a radial width of W 2 mm, the second riveting section 126 has a radial width of W 3 mm, the first riveting section 125 has a radial width of W 4 mm, satisfying: 1.8 ≤ W ≤ 2.5, 3.0 ≤ W 1 ≤ 4.2, 1.0 ≤ W 2 ≤ 1.5, 1.0 ≤ W 3 ≤ 1.5, 0.15 ≤ W 4≤0.75. It should be understood that by limiting W, W 1 , W 2 , W 3 , and W 4 within the above ranges to ensure the structural strength of the terminal post 12. Among them, by limiting the radial width of the main body portion 122 to be between 1.8 mm and 2.5 mm, while being adapted to the assembly hole 110 of the cover plate body 11, it is ensured that when the terminal post 12 bears a large external force, the main body portion 122 will not be deformed or even fractured. Specifically, W can be any value among 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm or the range value between two values. Within the above ranges, the larger W is, the higher the structural strength of the main body portion 122, and it is not easy to deform. At the same time, the gap between the main body portion 122 and the cover plate body 11 is smaller, and less sealing material is required. When W is smaller, the mass of the main body portion 122 is lighter, which is beneficial to the lightweight design of the battery.

[0061] By limiting the radial width of the first connecting portion 121 to be between 3.0 mm and 4.2 mm, it is ensured that there is sufficient contact area between the first connecting portion 121 and the cover plate body 11, and the support between the first connecting portion and the cover plate body is more firm. Specifically, W 1 can be any value among 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm or the range value between two values. Within the above ranges, the larger W 1 is, the more firmly the first connecting portion 121 is connected to the cover plate body 11, and the better the force uniformity. It should be understood that a plastic sheet needs to be sandwiched between the first connecting portion 121 and the cover plate body 11 to avoid short circuits between different components. When W 1 is smaller, on the premise of ensuring structural stability, the space occupied on the cover plate body 11 is reduced to reserve the assembly space for the remaining components.

[0062] By limiting the radial width of the second connecting portion 123 to be between 1.0 mm and 1.5 mm, the structural strength of the second connecting portion 123 is ensured, and the risk of deformation during the assembly process of the terminal post and during the operation of the battery is reduced. It should be understood that the radial width W 2 of the second connecting portion 123 does not include the radial width W 4 dimension of the first riveting section 125. Specifically, W 2 can be any value among 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or the range value between two values. When W 2The larger it is, the higher the structural strength of the second connecting portion 123, and the higher the connection stability between the second connecting portion 123 and the main body portion 122. When W 2 is smaller, the space of the limiting groove 124 surrounded by the second connecting portion 123 is larger, providing more embedding space for the connecting block 14 to lock the second connecting portion 123 and the connecting block 14, improving the connection stability.

[0063] By limiting the radial width of the second riveting section 126 to be between 1.0 mm and 1.5 mm, the connection reliability between the second riveting section 126 and the sealing plate 13 is ensured, a tight sealing connection is formed between the sealing plate 13 and the pole column 12, preventing electrolyte leakage, and at the same time ensuring good electrical connection. Specifically, W 3 can be any value among 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or the range value between two values. When W 3 is larger, the connection between the second riveting section 126 and the sealing plate 13 is firmer, avoiding the connection failure between the sealing plate 13 and the second riveting section 126 and loosening; when W 3 is smaller, the space occupied on the cover plate body 11 is reduced to reserve the assembly space for the remaining components.

[0064] By limiting the radial width of the first riveting section 125 to be between 0.15 mm and 0.75 mm, the connection reliability between the first riveting section 125 and the connecting block 14 is ensured, avoiding insufficient connection strength between the connecting block 14 and the first riveting section 125, and when subjected to external force impact, the first riveting section 125 is deformed and fails. Specifically, W 4 can be any value among 0.15 mm, 0.25 mm, 0.35 mm, 0.45 mm, 0.55 mm, 0.65 mm, 0.75 mm or the range value between two values. When W 4 is larger, the locking area between the first riveting section 125 and the connecting block 14 is more, ensuring more uniform stress dispersion and more stable connection. When W 4 is smaller, the force transmission path between the first riveting section 125 and the connecting block 14 is shorter, the structural strength is higher, the connection position between the first riveting section 125 and the convex portion 141 is not easily deformed by force, and the connection between the connecting block 14 and the second connecting portion 123 is not easily loosened.

[0065] Please refer to Figure 7 As shown, in some embodiments, along the thickness direction X, the first connecting portion 121 has a thickness dimension L 1 mm, the second connecting portion 123 has a thickness dimension L 2 mm, the first riveting section 125 has a thickness dimension L 3 mm, and the convex portion 141 has a thickness dimension L 4mm, the connecting block 14 has a thickness dimension L 5 mm, the second riveting section 126 has a thickness dimension L 6 mm, satisfying: 1.5 ≤ L 1 ≤ 2.0, 1.15 ≤ L 2 ≤ 2.1, 0.35 ≤ L 3 ≤ 0.6, 0.2 ≤ L 4 ≤ 0.8, 0.65 ≤ L 5 ≤ 1.5, 0.6 ≤ L 6 ≤ 1.5. It should be understood that by limiting the thickness dimension of the first connecting portion 121 to be between 1.5 mm and 2.0 mm, it is ensured that the first connecting portion 121 has sufficient strength to support the pole 12 on the cover plate body 11. Specifically, L 1 can be any value among 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm or a range value between two numerical values. Within the above range, when L 1 is larger, the structural strength of the first connecting portion 121 is higher, it is not easily deformed, and the assembly position of the pole 12 is ensured to be stable; when L 1 is smaller, the thickness space required for the assembly of the cover plate assembly is smaller, realizing a lightweight design.

[0066] By limiting the thickness dimension of the second connecting portion 123 to be between 1.15 mm and 2.1 mm, it is ensured that there is sufficient space in the thickness direction X of the limiting groove 124 formed by the second connecting portion 123 and the main body portion 122 for the connecting block 14 to be embedded, ensuring a more stable connection between the connecting block 14 and the second connecting portion 123, making the fixing structure of the cover plate assembly 1 more compact and the structural layout more reasonable. Specifically, L 2 can be any value among 1.15 mm, 1.25 mm, 1.35 mm, 1.45 mm, 1.55 mm, 1.65 mm, 1.75 mm, 1.85 mm, 1.95 mm, 2.05 mm, 2.1 mm or a range value between two numerical values. Within the above range, when L 2 is larger, the space in the thickness direction X of the limiting groove 124 is larger, facilitating the assembly of the connecting block and improving the assembly efficiency. When L 2 is smaller, the fixing structure of the cover plate assembly 1 is more compact and the structural layout is more reasonable.

[0067] By limiting the thickness dimension of the first riveting section 125 to be between 0.35 mm and 0.6 mm, the structural strength of the first riveting section 125 is ensured, and a reliable connection is formed between the first riveting section 125 and the convex portion 141 of the connecting block 14. Specifically, L 3It can be any value among 0.35mm, 0.45mm, 0.55mm, 0.6mm or a range value between two values. Within the above range, when L 3 is larger, the structural strength of the first riveting section 125 is higher, and the reliability of the assembly connection between the terminal post 12 and the cover body 11 is higher; when L 3 is smaller, the space occupied inside the battery is less, improving the space utilization rate.

[0068] By limiting the thickness dimension of the second riveting section 126 to be between 0.6mm and 1.5mm, while ensuring the connection strength between the second riveting section 126 and the sealing plate 13, it is ensured that there is an adequate sealing path between the second riveting section 126 and the sealing plate 13. Specifically, L 6 can be any value among 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm or a range value between two values. Within the above range, when L 6 is larger, the structural strength of the second riveting section is higher, and at the same time, the sealing path formed between the second riveting section and the sealing plate is longer, and the sealing performance is better. When L 6 is smaller, the space occupied on the cover body 11 is smaller, improving the space utilization rate.

[0069] By limiting the thickness dimension of the connecting block 14 to be between 0.65mm and 1.5mm, it is ensured that the connecting block 14 has sufficient structural strength to stably clamp the cover body 11. Specifically, L 5 can be any value among 0.65mm, 0.75mm, 0.85mm, 0.95mm, 1.05mm, 1.15mm, 1.25mm, 1.35mm, 1.45mm, 1.5mm or a range value between two values. Within the above range, when L 5 is larger, the structural strength of the connecting block is higher, and the connection stability is higher. When L 5 is smaller, the space occupied inside the battery is less, improving the space utilization rate.

[0070] By limiting the thickness dimension of the convex portion 141 to be between 0.2mm and 0.8mm, to ensure the structural strength of the convex portion 141, the convex portion 141 forms a stable fit with the first riveting section 125, ensuring the stability after assembly. Specifically, L 4 can be any value among 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm or a range value between two values. Within the above range, when L 4 is larger, the structural strength of the convex portion 141 is higher, and the reliability of the assembly connection between the terminal post 12 and the cover body 11 is higher; when L 4The smaller it is, the easier it is for the convex portion 141 of the connecting block 14 to be embedded in the limiting groove 124 and cooperate with the first riveting section 125, improving the assembly efficiency.

[0071] Please refer to Figure 7 As shown, in some embodiments, the sealing plate 13 includes a connected first portion 131 and a second portion 132. The first portion 131 passes through the through hole 120, and the second portion 132 is located on the side of the first portion 131 away from the electrode assembly 2 and bears on the side of the first connecting portion 121 away from the main body portion 122; along the thickness direction X, the sealing plate 13 has a portion protruding from the second riveting section 126. Along the thickness direction X, the protruding portion has a thickness dimension D 1 mm, satisfying: 0.05 ≤ D 1 ≤ 0.2. It should be understood that the second portion 132 of the sealing plate 13 can support on the side of the first connecting portion 121 away from the main body portion 122, enhancing the stability of the sealing plate 13, effectively dispersing the stress inside the battery, and preventing the sealing plate 13 from deforming or displacing due to uneven stress; at the same time, ensuring the electrical connection reliability between the pole column 12 and the sealing plate 13. The sealing plate 13 has a portion protruding from the second riveting section 126. By restricting the protruding portion to be between 0.05 mm and 0.2 mm, it is prevented that the weld mark formed by welding the sealing plate 13 and the second riveting section 126 protrudes from the large surface of the sealing plate 13, avoiding the interference of the internal structure of the battery that may be caused by the protruding weld mark, and further ensuring the stability of the battery structure. Specifically, D 1 can be any value among 0.05 mm, 0.10 mm, 0.15 mm, 0.20 mm or the range value between two values. Within the above range, when D 1 is larger, the space for accommodating the weld mark is larger, and the safety is higher. The weld mark will not contact the rest of the components, resulting in the risk of short circuit. When D 1 is smaller, the space occupied inside the battery is less, and the space utilization rate is higher.

[0072] Please refer to Figure 5As shown, in some embodiments, the cover plate assembly 1 further includes a seal 17. The seal 17 includes a first seal section 171, a second seal section 172, and a third seal section 173. The first seal section 171 is disposed between the main body portion 122 and the cover plate body 11. The second seal section 172 is clamped between the cover plate body 11 and the connection block 14. The third seal section 173 is embedded in the limit groove 124 and is clamped between the main body portion 122 and the connection block 14. The first seal section 171 is respectively connected to the second seal section 172 and the third seal section 173. It should be understood that the first seal section 171 disposed between the main body portion 122 and the cover plate body 11 effectively fills the gap between the two, enhances the tightness of the connection between the main body portion 122 and the cover plate body 11, and at the same time forms an insulating protection between the main body portion 122 and the cover plate body 11. The second seal section 172 is clamped between the cover plate body 11 and the connection block 14. On the one hand, it forms an insulating protection between the cover plate body 11 and the connection block 14. On the other hand, the second seal section 172 can play a buffering role between the connection block 14 and the cover plate body 11, avoiding damage to the connection part due to stress concentration. The third seal section 173 is embedded in the limit groove 124 and is clamped between the main body portion 122 and the connection block 14, restricting the relative movement of the main body portion 122 and the connection block 14 in the limit groove 124, ensuring that the entire connection structure can remain stable under various working conditions, thereby improving the overall structural stability of the battery. The three-section seal section acts on the gaps between the main body portion 122 and the cover plate body 11, the cover plate body 11 and the connection block 14, and the main body portion 122 and the connection block 14 respectively, forming multiple sealing lines of defense, greatly reducing the risk of electrolyte leakage. In terms of electrical connection, the stable sealing structure avoids electrical faults such as short circuits caused by electrolyte leakage, ensures the stable transmission of current between components such as the pole 12 and the connection block 14, improves the electrical connection reliability during the charging and discharging process of the battery, and guarantees the efficient and stable operation of the battery.

[0073] Please refer to Figure 5 and Figure 7As shown, in some embodiments, a sunken groove 111 is formed on one side of the cover plate body 11 facing the connecting block 14. The sunken groove 111 communicates with the assembly hole 110 and the limiting groove 124; the sunken groove 111 has a first wall 1111 facing the connecting block 14, and the main body portion 122 has a second wall 1221 facing the connecting block 14. The first wall 1111 and the second wall 1221 are on the same plane perpendicular to the thickness direction X. It should be understood that by forming the sunken groove 111 on the cover plate body 11, it is used to accommodate the second sealing section 172, so as to reduce the space required for the assembly of the seal 17 and improve the space utilization rate. By setting the second wall 1221 of the main body portion 122 and the first wall 1111 of the sunken groove 111 on the same plane, it is ensured that the compression amounts of the second sealing section 172 and the third sealing section 173 are consistent, improving the assembly efficiency of the cover plate assembly 1 and ensuring the connection stability between the cover plate body 11, the connecting block 14 and the pole post 12. The forces on each component are evenly distributed, reducing the risk of structural damage caused by excessive local stress.

[0074] Please refer to Figures 4 to 7 As shown, in some embodiments, the electrode assembly 2 includes a tab 21, and the tab 21 passes through the through hole 120 and is connected to the sealing plate 13. It should be understood that the tab 21 can pass through the through hole 120 and be directly connected to the sealing plate 13. By welding a bus bar on the side of the sealing plate 13 facing away from the tab 21, the current inside the single cell can be led out to the outside, shortening the current flow path, reducing the internal resistance of the battery, and improving the performance of the product. The above structure of the cover plate assembly 1 cancels the connecting piece, reduces the internal resistance of the single cell, and at the same time reduces the welding process and the number of components, improving the assembly efficiency, reducing the cost, and enhancing the competitiveness of the product.

[0075] The embodiment of the present application also discloses a battery pack, including the single cell as described in the above embodiment. Therefore, it can have all the technical features and technical effects of the above single cell, which will not be elaborated here.

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

[0077] 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 cover plate assembly and an electrode assembly, wherein the electrode assembly is disposed on one side of the cover plate assembly in a thickness direction thereof; The cover plate assembly comprises: The cover body is provided with an assembly hole along the thickness direction; A pole having a through hole, the pole comprising a first connecting portion, a main body and a second connecting portion, the main body being inserted through the assembly hole, the first connecting portion being arranged at a side of the cover body away from the electrode assembly and connected to the main body, the second connecting portion being arranged at an end of the main body away from the first connecting portion, and the second connecting portion and the main body forming a limiting groove; The through hole penetrates the first connecting portion, the main body portion and the second connecting portion along the thickness direction; A connecting block is arranged on a side of the cover body away from the first connecting portion, is partially embedded in the limiting groove, and is connected to the second connecting portion, and the cover body is sandwiched between the first connecting portion and the connecting block; A sealing plate covers the through hole.

2. The single cell according to claim 1, characterized in that: The second connecting portion is provided with a first riveting section protruding in a direction away from the through hole, and is used to enclose a limiting groove; The connecting block is connected to the first riveted section; and / or the connecting block includes a convex portion, the convex portion is convexly arranged on a side of the connecting block facing the second connecting portion, the convex portion is embedded in the limiting groove, and abuts against the first riveted section.

3. The single cell according to claim 2, characterized in that: The first riveting section has a first step surface, and the first step surface is located on a side of the first riveting section away from the through hole; The connecting block has a second step surface, and the second step surface is arranged opposite to the first step surface; The cover plate assembly further includes a first welding portion, and the first welding portion connects the first step surface and the second step surface respectively.

4. The single cell according to claim 2, characterized in that: The first connecting portion is provided with a second riveted section protruding in a direction away from the cover plate body, and the second riveted section surrounds and connects the sealing plate; On a plane perpendicular to the thickness direction, the orthographic projection of the second riveting section is located outside the orthographic projection of the through hole; The cover plate assembly further includes a second welding portion, and the second welding portion is respectively connected to the sealing plate and the second riveted section.

5. The single cell according to claim 4, characterized in that: On a plane perpendicular to the thickness direction, the main body has a radial width of W mm, the first connecting portion has a radial width of W1 mm, the second connecting portion has a radial width of W2 mm, the second riveted section has a radial width of W3 mm, and the first riveted section has a radial width of W4 mm, satisfying: 1.8≤W≤2.5, 3.0≤W1≤4.2, 1.0≤W2≤1.5, 1.0≤W3≤1.5, 0.15≤W4≤0.75; And / or, along the thickness direction, the first connecting portion has a thickness dimension of L1 mm, the second connecting portion has a thickness dimension of L2 mm, the first riveted section has a thickness dimension of L3 mm, and the second riveted section has a thickness dimension of L6 mm, satisfying: 1.5≤L1≤2.0, 1.15≤L2≤2.1, 0.35≤L3≤0.6, 0.6≤L6≤1.5; And / or, the protrusion has a thickness dimension of L4 mm, the connecting block has a thickness dimension of L5 mm, 0.2≤L4≤0.8, 0.65≤L5≤1.

5.

6. The single cell according to claim 4, characterized in that: The sealing plate includes a first portion and a second portion connected to each other, the first portion is inserted into the through hole, the second portion is located on a side of the first portion away from the electrode assembly, and is supported on a side of the first connecting portion away from the main body; Along the thickness direction, the sealing plate has a portion protruding from the second riveting section, and along the thickness direction, the protruding portion has a thickness dimension D1 mm, satisfying: 0.05≤D1≤0.

2.

7. The single cell according to claim 1, characterized in that: The cover assembly also 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 main body and the cover body, the second sealing section is clamped between the cover body and the connecting block, the third sealing section is embedded in the limiting groove and clamped between the main body and the connecting block, and the first sealing section connects the second sealing section and the third sealing section respectively.

8. The single cell according to claim 1, characterized in that: A sink groove is formed on one side of the cover plate body facing the connecting block, and the sink groove is communicated with the assembly hole and the limiting groove; The sink has a first wall facing the connection block, and the main body has a second wall facing the connection block. The first wall and the second wall are on the same plane perpendicular to the thickness direction.

9. The single cell according to any one of claims 1 to 8, characterized in that: The electrode assembly includes a pole ear, and the pole ear passes through the through hole and is connected to the sealing plate.

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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