A cover assembly and a battery

Abstract

The application discloses a cover group structure and a battery. The cover group structure comprises a cover plate, a pole and a compression ring. The cover plate is formed with a pole hole penetrating through the outer surface and the inner surface of the cover plate. The pole comprises a first part, a second part and a third part connected coaxially in sequence. The second part is arranged in the pole hole. The first part and the third part are clamped to the cover plate from the outer surface and the inner surface. The compression ring is arranged between the first part and the outer surface. The projection area of the overlapping part of the first part and the compression ring is S1 along the axial direction of the pole hole. The projection area of the third part is S2. S1 / S2 is greater than or equal to 1 / 4. Compared with the prior art, S1 and S2 in the range of the ratio can effectively increase the extrusion range of the local sealant, enhance the longitudinal occlusion pressure formed by the first part and the third part of the pole after riveting and compression, and improve the sealing stability of the cover group structure. The compression ring is reserved with sufficient space, which is convenient for the cooperative assembly of the compression ring and other parts and is helpful to improve the electrical performance of the battery.

Description

Technical Field

[0001] This application relates to the field of new energy battery technology, and in particular to a cover assembly structure and battery. Background Technology

[0002] As the requirements for electrical connection reliability and durability continue to increase in applications such as power batteries, energy storage batteries, and start-stop power supplies, battery cover structures (which typically include cover plates, terminals, and pressure rings / seals for sealing and clamping) face more stringent challenges in terms of structural strength, sealing performance, vibration resistance, and thermal cycling resistance.

[0003] In existing technologies, the cover assembly structure often uses poles that pass through holes in the cover plate, and upper and lower pressing areas are formed on the inner and outer sides of the cover plate, respectively. Through riveting or flanging processes, the two ends of the pole, the cover plate, and the pressure ring work together to generate axial clamping force to achieve the dual functions of electrical connection and sealing fixation. Under the existing structural and process conditions, there is a common problem that the extension of the upper part of the pole (i.e., the first part located on the outer surface of the cover plate) is insufficient, resulting in a small effective contact area with the pressure ring and insufficient overall longitudinal interlocking pressure. Utility Model Content

[0004] In view of the shortcomings of the prior art, this application provides a cover assembly structure and battery that can increase the effective area of ​​riveting / clamping of the upper part of the electrode post to the pressure ring and increase the longitudinal engagement pressure.

[0005] To achieve the above objectives, this application adopts the following technical solution: A cover assembly structure includes a cover plate, a pole post, and a pressure ring. The cover plate has a pole post hole that penetrates the outer and inner surfaces of the cover plate. The pole post includes a first part, a second part, and a third part connected coaxially in sequence. The second part passes through the pole post hole, and the first part and the third part are clamped to the cover plate from the outer and inner surfaces. The pressure ring presses against the first part and the outer surface. Along the axial direction of the pole post hole, the projected area of ​​the overlapping portion of the first part and the pressure ring is S1, and the projected area of ​​the third part is S2, wherein S1 / S2≥1 / 4.

[0006] In one implementation, S1 / S2 ≤ 1 / 2.

[0007] In one embodiment, the projected area of ​​the pressure ring along the axial direction of the pole hole is S3, where 1 / 6 ≤ S1 / S3 ≤ 1 / 3.

[0008] In one embodiment, the second part has a slot, and the pressure ring portion extends into the slot.

[0009] In one embodiment, the slot is an annular groove surrounding the axis of the pole hole, and the projected area of ​​the slot along the axial direction of the pole hole is S4, where 1 / 4≤S4 / S1≤1 / 2.

[0010] In one embodiment, the pressure ring includes an integrally formed abutment portion and a free portion. The abutment portion presses against the first portion and the outer surface, and the free portion is exposed outside the first portion. The abutment portion and the free portion have the same height.

[0011] In one embodiment, the cross-section of the slot is rectangular along the radial direction of the pole hole.

[0012] In one embodiment, along the axial direction of the pole hole, the height of the second part is H1, and the height of the third part is H2, wherein 1 / 2 ≤ H1 / H2 ≤ 3 / 2.

[0013] In one embodiment, the pressure ring has a through hole along the radial direction of the pole hole, and the second part is sequentially inserted into the through hole and the pole hole. The diameter of the through hole is D1, and the diameter of the pressure ring is D2, wherein 1 / 8 ≤ D1 / D2 ≤ 1 / 2.

[0014] This application also adopts the following technical solution: providing a battery, including the cover assembly structure and the housing of the above embodiments, wherein the housing is connected to the cover assembly structure.

[0015] The beneficial effects of this application are as follows: This application provides a cover assembly structure and a battery. The cover assembly structure includes a cover plate, terminals, and a pressure ring. The cover plate has a terminal hole that penetrates the outer and inner surfaces of the cover plate. The terminal includes a first part, a second part, and a third part connected coaxially in sequence. The second part passes through the terminal hole, and the first and third parts are clamped to the cover plate from the outer and inner surfaces, respectively. The pressure ring presses against the first part and the outer surface. Along the axial direction of the terminal hole, the projected area of ​​the overlapping portion of the first part and the pressure ring is S1, and the projected area of ​​the third part is S2, wherein S1 / S2 ≥ 1 / 4. Compared with the prior art, S1 and S2 within this ratio range can effectively increase the extrusion range of the local sealing material, enhance the longitudinal interlocking pressure formed by the first and third parts of the terminal after riveting, thereby improving the sealing stability of the cover assembly structure, reserving sufficient space for the pressure ring, facilitating its assembly with other parts, and helping to improve the electrical performance of the battery. Attached Figure Description

[0016] Figure 1 A cross-sectional schematic diagram of a cover assembly structure according to this application is shown; Figure 2 Another cross-sectional schematic diagram of a cover assembly structure of this application is shown; Figure 3 A top view schematic diagram of a cover assembly structure according to this application is shown; Figure 4 A bottom view of one type of cover assembly structure of this application is shown; Figure 5 A cross-sectional schematic diagram of a pressure ring according to this application is shown; Reference numerals: 100, cover assembly structure; 1, cover plate; 11, pole hole; 12, outer surface; 13, inner surface; 2, pole; 21, first part; 22, second part; 221, slot; 23, third part; 3, pressure ring; 31, perforation; 32, abutment part; 33, free part; 4, sealant. Detailed Implementation

[0017] In this application, the terms "set up," "equipped with," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0018] The terms “center,” “longitudinal,” “lateral,” “length,” “width,” “thickness,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” “outer,” “radial,” and “circumferential” indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] See Figure 1 This application provides a battery including a cover structure 100 and a housing (not shown in the figure). The cover structure 100 is connected to the housing to enclose and form a receiving space. The core package is disposed in the receiving space and connected to the cover structure 100 so as to make conductive connection between the electrode lead-out end of the core package and the terminal post 2 in the cover structure 100.

[0021] See again Figures 1-4The cover assembly structure 100 includes a cover plate 1, a pole post 2, and a pressure ring 3. The cover plate 1 has a pole post hole 11 that penetrates the outer surface 12 and the inner surface 13 of the cover plate 1. The pole post 2 includes a first part 21, a second part 22, and a third part 23 that are coaxially connected in sequence. The second part 22 passes through the pole post hole 11. The first part 21 and the third part 23 are clamped to the cover plate 1 from the outer surface 12 and the inner surface 13. The pressure ring 3 presses against the first part 21 and the outer surface 12. Along the axial direction of the pole post hole 11, the projected area of ​​the overlapping part of the first part 21 and the pressure ring 3 is S1, and the projected area of ​​the third part 23 is S2, wherein S1 / S2≥1 / 4.

[0022] In practical applications, a sealant 4 is provided between the cover plate 1 and the pole post 2. The cover plate 1 has a pole post hole 11, and the sealant 4 passes through the pole post hole 11. The second part 22 of the pole post 2 is inserted into the sealant 4 with an interference fit or clearance fit. The first part 21 is located on the outer surface 12 side of the cover plate 1, and the third part 23 is located on the inner surface 13 side of the cover plate 1. The first part 21 and the third part 23 form a double-sided riveting or flanging axial limiting structure relative to the inner surface 13 of the cover plate 1. The pressure ring 3 is disposed between the first part 21 and the outer surface 12 of the cover plate 1. During the riveting or flanging process, the pressure ring 3 makes surface contact with the first part 21 and bears the constraint of axial load and local deformation. Along the axial direction of the pole hole 11, the overlapping part of the first part 21 and the pressure ring 3 is defined as the effective force-bearing area, and its projected area in the axial direction is S1; the projected area of ​​the third part 23 relative to the inner surface 13 of the cover plate 1 is defined as S2, where S1 / S2≥1 / 4, for example, S1=1 / 4S2, S1=1 / 3S2, etc.

[0023] Within this ratio range, S1 and S2 can effectively increase the compression range of the local sealing material 4, enhance the longitudinal interlocking pressure formed by the first part 21 and the third part 23 of the terminal post 2 after riveting, thereby improving the sealing stability of the cover assembly structure 100, reserving sufficient space for the pressure ring 3, facilitating its assembly with other parts, and helping to improve the battery's electrical performance. If S1 / S2 is less than 1 / 4, the effective riveting area of ​​the first part 21 of the terminal post 2 on the pressure ring 3 is insufficient, resulting in a reduction in the longitudinal interlocking pressure formed by it and the third part 23 of the terminal post 2, thereby weakening the battery's sealing performance.

[0024] In one embodiment, S1 / S2≤1 / 2. If S1 is too large, it will affect the coordination between the cover assembly structure 100 and other parts because the cover assembly structure 100 has not reserved enough assembly space. Therefore, the ratio of S1 / S2 needs to be controlled within 1 / 2, and the most preferred ratio of S1 / S2 is 1 / 3.

[0025] See Figure 2Along the axial direction of the terminal hole 11, the projected area of ​​the pressure ring 3 is S3, where 1 / 6 ≤ S1 / S3 ≤ 1 / 3, preferably S1 / S3 = 1 / 5. If S1 / S3 is less than 1 / 6, the effective riveting area S1 between the first part 21 and the pressure ring 3 will be too small, resulting in ineffective riveting and battery leakage. If S1 / S3 is greater than 1 / 3, the effective area S1 between the first part 21 and the pressure ring 3 will be too large, causing the external short-circuit protection components to fail. Therefore, S1 / S3 is controlled between 1 / 6 and 1 / 3, and can be values ​​such as 1 / 6, 1 / 5, or 1 / 4.

[0026] See again Figure 2 The second part 22 has a slot 221, and the pressure ring 3 extends into the slot 221. In practical applications, the second part 22 has an annular slot 221 formed around its circumference, and the inner edge of the pressure ring 3 is set as an insertion section that matches the slot 221. During assembly, the insertion section of the pressure ring 3 extends into the slot 221 to form a geometric engagement, which improves the relative positioning accuracy and anti-slip capability between the pressure ring 3 and the pole post 2.

[0027] See again Figure 2 The slot 221 is an annular groove surrounding the axis of the pole hole 11. Along the axial direction of the pole hole 11, the projected area of ​​the slot 221 is S4, where 1 / 4≤S4 / S1≤1 / 2.

[0028] In practical applications, along the axial direction of the pole post hole 11, the projected area of ​​the slot 221 in the axial direction is defined as S4, and the effective force-overlapping projected area of ​​the first part 21 and the pressure ring 3 in the axial direction is defined as S1. S4 / S1 is controlled between 1 / 4 and 1 / 2 to achieve a reasonable match between the annular groove meshing area and the inner force-bearing area. When S4 / S1 is less than 1 / 4, S4 is too small, and the insertion depth of the pressure ring 3 is too shallow, easily causing the pressure ring 3 to detach from the second part 22. When S4 / S1 is greater than 1 / 2, S4 is too large, and the area of ​​the slot 221 is too large, easily causing insufficient overall structural rigidity of the pole post 2, structural instability, and insufficient riveting support. Preferably, S4 / S1 can be a value such as 1 / 3.

[0029] See again Figure 2 The pressure ring 3 includes an integrally formed abutment portion 32 and a free portion 33. The abutment portion 32 presses against the first portion 21 and the outer surface 12, and the free portion 33 is exposed outside the first portion 21. The abutment portion 32 and the free portion 33 have the same height.

[0030] In practical applications, the pressure ring 3 is an integrally formed structure, comprising a coaxially arranged abutment portion 32 and a free portion 33, both with the same height in the axial direction. The abutment portion 32 is located between the outer surface 12 of the cover plate 1 and the first part 21 of the pole post 2, with its end face forming a surface contact with the outer surface 12 of the cover plate 1, and its reverse end face forming a supporting contact with the end face of the first part 21, providing stable support and load diffusion during the riveting process; the free portion 33 is circumferentially integral with the abutment portion 32, extending outward and exposed outside the outer diameter or end face of the first part 21, and is not covered by the first part 21 during riveting. By integrally forming the pressure ring 3 into an abutment portion 32 and a free portion 33 of equal height, and placing the abutment portion 32 between the first part 21 and the outer surface 12 of the cover plate 1, and the free portion 33 exposed outside the first part 21, the problem of uneven load distribution caused by segmented or unequal height structures of the pressure ring 3 in the prior art is solved.

[0031] See again Figure 2 Along the radial direction of the pole post hole 11, the cross-section of the slot 221 is rectangular. In practical applications, the cross-section of the slot 221 adopts a rectangular cross-section structure to form a surface-to-surface fit with the insertion section of the pressure ring 3, providing a controllable surface contact zone and clear sidewall positioning, so that the insertion section of the pressure ring 3 obtains circumferential continuous surface support.

[0032] It should be noted that the cross-section of slot 221 specifically refers to the geometric section selected relative to the axis of pole hole 11. For example, a cross-section formed by the axis of pole hole 11.

[0033] See again Figure 2 Along the axial direction of the pole hole 11, the height of the second part 22 is H1, and the height of the third part 23 is H2, where 1 / 2≤H1 / H2≤3 / 2.

[0034] In practical applications, the segmented structure of the pole post 2 is defined along the axial direction of the pole post hole 11. The axial height of the second part 22 is denoted as H1, and the axial height of the third part 23 is denoted as H2, and the two are made to satisfy the ratio 1 / 2 ≤ H1 / H2 ≤ 3 / 2. The above ratio range ensures that the second part 22 and the third part 23 are in a relatively balanced range in axial dimensions, that is, their heights will not be excessively unbalanced.

[0035] Specifically, if H1 / H2 is less than 1 / 2, the sealant 4 will be over-compressed, leading to plastic deformation or overflow, causing the sealing interface of the cover assembly structure 100 to fail, which is detrimental to the sealing performance of the battery. If H1 / H2 is more than 3 / 2, the sealant 4 will not be compressed enough to form an effective seal, which will also reduce the sealing reliability of the battery. The preferred range of the H1 / H2 ratio is 3 / 4 to 1, and the optimal ratio is H1 / H2 = 1.

[0036] See Figure 5Along the radial direction of the pole post hole 11, the pressure ring 3 has a through hole 31. The second part 22 is sequentially inserted into the through hole 31 and the pole post hole 11. The diameter of the through hole 31 is D1, and the diameter of the pressure ring 3 is D2, wherein 1 / 8≤D1 / D2≤1 / 2.

[0037] In practical applications, setting D1 / D2 between 1 / 8 and 1 / 2 can effectively increase the riveting area of ​​the first part 21 of the terminal post 2 against the pressure ring 3, enhancing the local compaction effect on the sealant 4 and thus improving the sealing reliability of the battery. On the other hand, it can improve the assembly tightness between the terminal post 2 and the pressure ring 3, enhance the stability of the cover assembly structure 100 in the riveting state, and help reduce the internal resistance of the battery.

[0038] If D1 / D2 is less than 1 / 8, the diameter of the perforation 31 will be too small, which may lead to an interference fit between the pressure ring 3 and the terminal post 2, causing assembly difficulties and preventing the successful riveting of the cover assembly. If D1 / D2 is greater than 1 / 2, it will weaken the assembly tightness between the terminal post 2 and the pressure ring 3, reduce the riveting area of ​​the first part 21 on the pressure ring 3, weaken the compaction effect on the sealing material 4, and thus adversely affect the sealing reliability of the battery. Preferably, the range of D1 / D2 can be 1 / 7 to 1 / 5, and the optimal setting is 1 / 6.

[0039] To clearly illustrate the beneficial effects of the embodiments of this application, the following comparative experiments were conducted. As shown in Table 1 below, in Embodiment 1, the ratio of S1 / S2 was selected as 1 / 3, the ratio of H1 / H2 was selected as 1, and the ratio of D1 / D2 was selected as 1 / 6.

[0040] Table 1 Comparison of parameters between the examples and comparative examples.

[0041] Table 2 Comparison of Results between Examples and Comparative Examples

[0042] The results of the above embodiments and comparative examples show that, under the conditions specified in this utility model, the electrolyte evaporation can be reduced, thereby improving the battery's sealing performance. Furthermore, in high-temperature environments, it can effectively prevent poor internal contact caused by deformation of the cover structure due to thermal expansion of the sealing material. Therefore, the battery characteristics will not deteriorate, and the battery's electrical performance stability is higher.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] Furthermore, in addition to indicating location or positional relationship, some of the aforementioned terms may also have other meanings. For example, the term "above" may also be used in some cases to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application based on the specific circumstances.

[0045] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A cover assembly structure, characterized in that, include: The cover plate has pole holes that penetrate the outer and inner surfaces of the cover plate; The pole post includes a first part, a second part, and a third part connected coaxially in sequence. The second part passes through the pole post hole, and the first part and the third part are clamped to the cover plate from the outer surface and the inner surface, respectively. A pressure ring is pressed between the first part and the outer surface. Along the axial direction of the pole hole, the projected area of ​​the overlapping part of the first part and the pressure ring is S1, and the projected area of ​​the third part is S2, wherein S1 / S2≥1 / 4.

2. The cover assembly structure according to claim 1, characterized in that, The ratio S1 / S2 is less than or equal to 1 / 2.

3. The cover assembly structure according to claim 1, characterized in that, Along the axial direction of the pole hole, the projected area of ​​the pressure ring is S3, where 1 / 6≤S1 / S3≤1 / 3.

4. The cover assembly structure according to claim 1, characterized in that, The second part has a slot, and the pressure ring part extends into the slot.

5. The cover assembly structure according to claim 4, characterized in that, The slot is an annular groove surrounding the axis of the pole hole. Along the axial direction of the pole hole, the projected area of ​​the slot is S4, where 1 / 4≤S4 / S1≤1 / 2.

6. The cover assembly structure according to claim 4, characterized in that, The pressure ring includes an integrally formed abutment portion and a free portion. The abutment portion presses against the first portion and the outer surface, and the free portion is exposed outside the first portion. The abutment portion and the free portion have the same height.

7. The cover assembly structure according to claim 4, characterized in that, Along the radial direction of the pole hole, the cross-section of the slot is rectangular.

8. The cover assembly structure according to any one of claims 1 to 7, characterized in that, Along the axial direction of the pole hole, the height of the second part is H1, and the height of the third part is H2, wherein 1 / 2 ≤ H1 / H2 ≤ 3 / 2.

9. The cover assembly structure according to any one of claims 1 to 7, characterized in that, Along the radial direction of the pole post hole, the pressure ring has a through hole, and the second part is sequentially inserted into the through hole and the pole post hole. The diameter of the through hole is D1, and the diameter of the pressure ring is D2, wherein 1 / 8≤D1 / D2≤1 / 2.

10. A battery, characterized in that, It includes the cover assembly structure and the housing as described in any one of claims 1 to 9, wherein the housing is connected to the cover assembly structure.

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