Cover assembly of battery and secondary battery

Abstract

The utility model provides a kind of cover plate assembly and secondary battery of battery, cover plate assembly includes cover plate, pole and sealing ring;Cover plate includes cover plate body and first communication hole, pole includes first pole part and second pole part, sealing ring includes first sealing part and second sealing part, first pole part passes through first communication hole, first sealing part is set to the outer periphery of first pole part and extends into first communication hole, second sealing part is clamped between cover plate body and second pole part;Second sealing part includes compression segment, the ratio of the thickness of compression segment and ring width is less than 0.4.The utility model increases the escape travel of electrolyte in the radial direction of first communication hole by the ring width of compression segment is designed to be larger value to increase electrolyte escape difficulty, improve the sealing performance of sealing ring without changing the thickness of compression segment.And because the thickness of compression segment is invariable, the rebound force generated after compression segment is compressed is reduced, so the installation difficulty of cover plate assembly is reduced.

Description

Technical Field

[0001] This utility model relates to the field of batteries, and in particular to a cover plate assembly for a battery and a secondary battery. Background Technology

[0002] The secondary battery includes a cover assembly, a housing, and a cell assembly. The cell assembly is housed within the housing, and the cover assembly is installed at the opening of the housing and electrically connected to the cell assembly, allowing the electrical energy from the cell assembly to be led out to the outside of the housing through the terminals on the cover assembly. The cover plate in the cover assembly has a connecting hole for the terminals to pass through, and a sealed connection is required between the terminals and the connecting hole to prevent electrolyte leakage from the inside of the housing to the outside.

[0003] Existing technology achieves a sealed connection between the terminal and the cover plate through an O-ring. The O-ring includes a first sealing portion extending into the connecting hole and a second sealing portion sandwiched between the cover plate and the terminal. After prolonged use, the sealing performance of the O-ring weakens, and electrolyte may escape through gaps between the cover plate and the second sealing portion or between the terminal and the second sealing portion. While increasing the thickness of the second sealing portion can improve the sealing performance to some extent, it increases the rebound force generated after compression during installation, making the cover plate assembly more difficult to install, especially when other structural dimensions of the cover plate assembly remain unchanged. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the defect in the prior art that increasing the thickness of the sealing ring sandwiched between the cover plate and the terminal post will increase the difficulty of installing the cover plate assembly, and to provide a cover plate assembly for a battery and a secondary battery.

[0005] The present invention solves the above-mentioned technical problems through the following technical solution:

[0006] A battery cover assembly includes a cover, terminals, and a sealing ring;

[0007] The cover plate includes a cover plate body and a first connecting hole, wherein the first connecting hole penetrates the cover plate body at both ends in the thickness direction of the cover plate;

[0008] The pole post includes a first pole post portion and a second pole post portion. The first pole post portion passes through the first connecting hole, and the second pole post portion is located on one side of the cover plate body in the thickness direction of the cover plate. The second pole post portion extends radially outward from the outer peripheral surface of the first pole post portion toward the first connecting hole and beyond the first connecting hole.

[0009] The sealing ring includes a first sealing part and a second sealing part. The first sealing part is sleeved on the outer periphery of the first pole post and extends into the first connecting hole. The second sealing part extends radially outward from the outer peripheral surface of the first sealing part toward the first connecting hole and beyond the first connecting hole. The two ends of the second sealing part abut against the cover plate body and the second pole post respectively in the thickness direction of the cover plate.

[0010] The second sealing part includes a pressing section, the projection of which along the thickness direction of the cover plate onto the cover plate body completely overlaps with the cover plate body; the thickness of the pressing section along the thickness direction of the cover plate is defined as H, and the circumferential width of the pressing section in the radial direction of the cover plate is defined as D; wherein, H / D < 0.4.

[0011] In this design, without changing the thickness of the clamping section, the ring width of the clamping section is increased to meet the ratio range of the thickness H to the ring width D. This increased ring width increases the radial dimension of the clamping section within the first connecting hole, thereby increasing the escape distance of the electrolyte in the radial direction, making electrolyte escape more difficult, and improving the sealing performance of the sealing ring. Furthermore, since the thickness of the clamping section remains constant, the rebound force generated after compression is reduced, thus alleviating the installation difficulty of the cover plate assembly and avoiding assembly difficulties caused by an excessively thick sealing ring.

[0012] Preferably, the circumferential width D of the clamping section in the radial direction of the cover plate ranges from 1.7 mm to 3.5 mm.

[0013] In this solution, by limiting the specific range of the ring width of the pressing section, it is ensured that the pressing section has sufficient sealing contact area in the radial direction of the first connecting hole, thereby effectively improving the sealing performance of the sealing ring.

[0014] Preferably, the circumferential width D of the clamping section in the radial direction of the cover plate is in the range of 2.5mm to 3.5mm.

[0015] In this solution, by further defining the specific range of the ring width of the pressing section, it is ensured that the pressing section has sufficient sealing contact area in the radial direction of the first connecting hole, thereby effectively improving the sealing performance of the sealing ring.

[0016] Preferably, the thickness H of the pressing section in the thickness direction of the cover plate is less than the thickness of the cover plate body in the thickness direction of the cover plate.

[0017] Preferably, the thickness H of the pressing section in the thickness direction of the cover plate ranges from 0.58 mm to 0.82 mm.

[0018] In this solution, by limiting the thickness of the compression section, the compression ratio and resilience of the sealing ring are optimized, so that it can maintain a good sealing state during long-term use, while also facilitating assembly.

[0019] Preferably, the diameter of the first connecting hole is larger than the outer diameter of the first sealing part.

[0020] In this solution, the above-mentioned arrangement reduces the resistance of the first sealing part extending into the first connecting hole, prevents the first sealing part from being excessively deformed during installation, reduces installation difficulty, and improves installation efficiency and the service life of the sealing ring.

[0021] Preferably, the end face of the cover plate body in the thickness direction of the cover plate transitions with the inner wall surface of the first communicating hole in an arc.

[0022] In this solution, the above-mentioned settings reduce stress concentration, minimize damage to the sealing ring during assembly, and extend the service life of the sealing ring.

[0023] Preferably, the sealing ring has a second through hole through which the pole post passes, the second through hole extending through both ends of the cover plate in the thickness direction;

[0024] The electrode post is a copper-aluminum composite electrode post, which includes a copper segment and an aluminum segment, and the junction of the copper segment and the aluminum segment is located inside the second connecting hole.

[0025] In this solution, the above-mentioned arrangement avoids the end face of the sealing ring in the thickness direction of the cover plate being flush with the junction of the copper and aluminum sections, thus preventing the junction of the copper and aluminum sections from directly bearing the rebound force of the pressing section and reducing the risk of separation between the copper and aluminum sections.

[0026] Preferably, the sealing ring is made of rubber.

[0027] In this design, the rubber has good elasticity, which allows the clamping section to be compressed during the assembly of the cover plate assembly, thereby reducing the gap between the clamping section and the cover plate and the electrode post, increasing the difficulty of electrolyte escape, and maintaining a stable sealing effect during long-term battery use.

[0028] A secondary battery includes a cover assembly for the battery as described above.

[0029] In this solution, the secondary battery uses the cover plate assembly described above, which enables the secondary battery to have excellent sealing performance, convenient installation and long-term reliability, effectively preventing electrolyte leakage and improving battery life and safety.

[0030] The positive and progressive effects of this invention are as follows: Without changing the thickness of the clamping section, by designing a larger ring width to satisfy the ratio range of the thickness H to the ring width D, the increased ring width increases the radial dimension of the clamping section within the first connecting hole. This increases the escape distance of the electrolyte within the first connecting hole, making electrolyte escape more difficult and improving the sealing performance of the sealing ring. Furthermore, since the thickness of the clamping section remains constant, the rebound force generated after compression is reduced, thereby alleviating the installation difficulty of the cover plate assembly and avoiding assembly difficulties caused by an excessively thick sealing ring. Attached Figure Description

[0031] Figure 1 This is a three-dimensional structural diagram of a secondary battery according to an embodiment of the present invention.

[0032] Figure 2 This is an explosion diagram of a secondary battery according to an embodiment of the present invention.

[0033] Figure 3 This is an exploded view of the cover plate assembly of a battery according to an embodiment of the present invention.

[0034] Figure 4 This is a top view of the cover plate assembly of a battery according to an embodiment of the present invention.

[0035] Figure 5 for Figure 4 A schematic diagram of the cross-sectional structure along the middle AA.

[0036] Figure 6 for Figure 5 Enlarged view of part B in the image.

[0037] Figure 7 for Figure 6 Enlarged view of section C in the image.

[0038] Explanation of reference numerals in the attached figures:

[0039] Casing 1

[0040] Cover plate assembly 2

[0041] Cover plate 21

[0042] Cover body 211

[0043] First connecting hole 212

[0044] pole 22

[0045] First pole section 221

[0046] Second pole section 222

[0047] Copper section 223

[0048] Aluminum section 224

[0049] Sealing ring 23

[0050] Sealing ring body 231

[0051] First sealing part 2311

[0052] Second sealing part 2312

[0053] Compactor section 23121

[0054] Second connecting hole 232

[0055] Lower plastic 24

[0056] 25g of plastic

[0057] Conductive block 26

[0058] Battery cell assembly 3

[0059] Storage space 4 Detailed Implementation

[0060] The present invention will be described more clearly and completely below with reference to the accompanying drawings, using a preferred embodiment.

[0061] like Figure 1 and Figure 2 As shown, this embodiment discloses a secondary battery, including a housing 1, a cover assembly 2, and a cell assembly 3. The cell assembly 3 is disposed inside the housing 1, and the cover assembly 2 covers the open end of the housing 1 to form a sealed receiving space 4.

[0062] In this embodiment, the secondary battery is a secondary battery with terminals at both ends. Specifically, in this embodiment, there are two cover plate assemblies 2, each with a positive terminal and a negative terminal installed on it. The housing 1 has two openings that are arranged opposite to each other, and the two cover plate assemblies 2 cover the two openings of the housing 1 respectively.

[0063] like Figures 3-7 As shown, the cover assembly 2 includes a cover plate 21, a terminal post 22, a sealing ring 23, a lower plastic 24, an upper plastic 25, and a conductive block 26. The lower plastic 24 is located at the end of the cover plate 21 facing the receiving space 4, while the upper plastic 25 and the conductive block 26 are located at the end of the cover plate 21 facing the external space of the secondary battery. The terminal post 22 passes through the cover plate 21, with its end facing the receiving space 4 electrically connected to the cell assembly 3, and its end facing the external space of the secondary battery connected to the conductive block 26 for electrical connection with electrical equipment. The sealing ring 23 provides insulation between the terminal post 22 and the cover plate 21.

[0064] Specifically, such as Figures 3-7As shown, the cover plate 21 includes a cover plate body 211 and a first connecting hole 212. The first connecting hole 212 penetrates the cover plate body 211 at both ends in the thickness direction of the cover plate 21. The electrode post 22 includes a first electrode post portion 221 and a second electrode post portion 222. The second electrode post portion 222 is located at the end of the first electrode post portion 221 facing the receiving space 4 in the thickness direction of the cover plate 21 (i.e., located on the side of the cover plate body 211 facing the receiving space 4 in the thickness direction of the cover plate 21). The first electrode post portion 221 passes through the first connecting hole 212. The end of the first electrode post portion 221 facing the external space of the secondary battery is connected to the conductive block 26. The conductive block 26 can increase the electrical connection area between the secondary battery and the electrical device. The second pole post 222 extends radially outward from the outer peripheral surface of the first pole post 221 toward the first connecting hole 212 and beyond the first connecting hole 212. The second pole post 222 and the cover plate body 211 form a gap in the thickness direction of the cover plate 21 to accommodate the plastic 24 and the sealing ring 23.

[0065] The lower plastic 24 is sandwiched between the cover plate body 211 and the second electrode post 222 in the thickness direction of the cover plate 21, and the upper plastic 25 is sandwiched between the cover plate body 211 and the conductive block 26 in the thickness direction of the cover plate 21. The sealing ring 23 includes a sealing ring body 231 and a second connecting hole 232. The second connecting hole 232 penetrates the sealing ring body 231 at both ends in the thickness direction of the cover plate 21 to allow the electrode post 22 to pass through. The sealing ring body 231 includes a first sealing part 2311 and a second sealing part 2312. The first sealing part 2311 is sleeved on the outer periphery of the first pole post 221 and extends into the first connecting hole 212. The second sealing part 2312 extends radially outward from the outer peripheral surface of the first sealing part 2311 toward the first connecting hole 212 and beyond the first connecting hole 212. The two ends of the second sealing part 2312 in the thickness direction of the cover plate 21 respectively abut against the cover plate body 211 and the second pole post 222, thereby achieving insulation between the pole post 22 and the cover plate body 211.

[0066] Furthermore, the diameter of the first connecting hole 212 is larger than the outer diameter of the first sealing part 2311, so as to reduce the resistance of the first sealing part 2311 extending into the first connecting hole 212, prevent the first sealing part 2311 from being excessively deformed during installation, reduce the installation difficulty, improve the installation efficiency and the service life of the sealing ring 23.

[0067] like Figure 7 As shown, the second sealing portion 2312 includes a pressing section 23121. Specifically, the pressing section 23121 is the portion of the second sealing portion 2312 whose projection along the thickness direction of the cover plate 21 onto the cover plate body 211 can completely overlap with the cover plate body 211. The thickness of the pressing section 23121 in the thickness direction of the cover plate 21 is defined as H, and the circumferential width of the pressing section 23121 in the radial direction of the cover plate 21 is defined as D; where H / D < 0.4.

[0068] It should be noted that the circumference of the pressing section 23121 in the radial direction of the cover plate 21 described in this embodiment specifically refers to the difference between the outer diameter and the inner diameter of the pressing section 23121 in the radial direction of the cover plate 21.

[0069] Compared with the prior art, this embodiment only increases the circumferential width D of the pressing section 23121 in the radial direction of the cover plate 21, without changing the thickness H of the pressing section 23121 in the thickness direction of the cover plate 21.

[0070] Specifically, the thickness H of the pressing section 23121 in the thickness direction of the cover plate 21 remains unchanged, adopting a conventional dimension in the current prior art, generally ranging from 0.58mm to 0.82mm, and ensuring that the thickness H of the pressing section 23121 in the thickness direction of the cover plate 21 is less than the thickness of the cover plate body 211 in the thickness direction of the cover plate 21. This embodiment optimizes the compression ratio and resilience performance of the sealing ring 23 by limiting the thickness of the pressing section 23121, enabling it to maintain a good sealing state during long-term use, while also facilitating assembly.

[0071] The circumferential width D of the pressing section 23121 in the radial direction of the cover plate 21 ranges from 1.7mm to 3.5mm, and is further preferably 2.5mm to 3.5mm, which is larger than the size used in the prior art, so as to ensure that the pressing section 23121 has sufficient sealing contact area in the radial direction of the first connecting hole 212, and effectively improves the sealing performance of the sealing ring 23.

[0072] In this embodiment, without changing the thickness of the compression section 23121, the circumferential width of the compression section 23121 is designed to be larger to satisfy the ratio range of the thickness H to the circumferential width D of the compression section 23121. The increased circumferential width of the compression section 23121 increases its radial dimension in the first connecting hole 212, thereby increasing the escape distance of the electrolyte in the radial direction of the first connecting hole 212, increasing the difficulty of electrolyte escape, and improving the sealing performance of the sealing ring 23. Furthermore, since the thickness of the compression section 23121 remains unchanged, the rebound force generated after compression is reduced, thereby alleviating the installation difficulty of the cover assembly 2 and avoiding assembly difficulties caused by excessive thickness of the sealing ring 23. Using the cover assembly 2 described above in the secondary battery gives the secondary battery excellent overall sealing performance, ease of installation, and long-term reliability, effectively preventing electrolyte leakage and improving battery life and safety.

[0073] Furthermore, such as Figure 7As shown, the end face of the cover plate body 211 in the thickness direction of the cover plate 21 transitions with the inner wall surface of the first connecting hole 212 through an arc, that is, the edge of the opening of the first connecting hole 212 is rounded. Specifically, the two sides of the cover plate body 211 abut against the sealing ring 23 and the upper plastic 25 respectively. Therefore, in this embodiment, both openings of the first connecting hole 212 in the thickness direction of the cover plate 21 are rounded to reduce stress concentration, reduce damage to the sealing ring 23 and the upper plastic 25 during assembly, and extend the service life of the sealing ring 23 and the upper plastic 25.

[0074] In other alternative embodiments, the chamfering of the opening edge of the first connecting hole 212 may not be performed.

[0075] Furthermore, in this embodiment, the sealing ring 23 is made of rubber, which has good elasticity so that the pressing section 23121 can be compressed during the assembly of the cover plate assembly 2, thereby reducing the gap between the pressing section 23121 and the cover plate 21 and the electrode post 22, increasing the difficulty of electrolyte escape, and maintaining a stable sealing effect during long-term use of the battery.

[0076] In other alternative embodiments, the sealing ring 23 can also be made of other materials capable of achieving the above-described functions. Preferably, the sealing ring 23 is made of a corrosion-resistant material to avoid corrosion by the electrolyte.

[0077] Furthermore, such as Figure 7 As shown, in this embodiment, the electrode post 22 is a copper-aluminum composite electrode post, comprising a copper segment 223 and an aluminum segment 224, which are joined together as a whole using processes such as friction welding. The copper segment 223 is connected to the end of the aluminum segment 224 facing the receiving space 4 for connection to the battery cell assembly 3. The conductive block 26 is made of the same material as the aluminum segment 224 to facilitate connection between the two for connecting electrical equipment.

[0078] like Figure 7 As shown, the junction of the copper segment 223 and the aluminum segment 224 is located within the second connecting hole 232. That is, the end face of the sealing ring 23 facing the receiving space 4 in the thickness direction of the cover plate 21 is closer to the receiving space 4 than the junction of the copper segment 223 and the aluminum segment 224. This is to prevent the end face of the sealing ring 23 facing the receiving space 4 in the thickness direction of the cover plate 21 from being flush with the junction of the copper segment 223 and the aluminum segment 224, and to prevent the junction of the copper segment 223 and the aluminum segment 224 from directly bearing the rebound force of the pressing segment 23121, thereby reducing the risk of separation of the copper segment 223 and the aluminum segment 224.

[0079] In other alternative embodiments, the end face of the sealing ring 23 facing the receiving space 4 in the thickness direction of the cover plate 21 may also be flush with the junction of the copper section 223 and the aluminum section 224.

[0080] In other alternative implementations, the pole piece 22 may also be made of a single material.

[0081] The sealing ring 23 mentioned above is also applicable to top-outlet secondary batteries, i.e., secondary batteries that consist of only one cover assembly, on which both the positive and negative terminals are mounted.

[0082] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship of the device or component shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component 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 utility model.

[0083] While specific embodiments of this utility model have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of this utility model is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of this utility model, but all such changes and modifications fall within the scope of protection of this utility model.

Claims

1. A battery cover assembly, characterized in that, Includes cover plate (21), pole post (22) and sealing ring (23); The cover plate (21) includes a cover plate body (211) and a first connecting hole (212), wherein the first connecting hole (212) penetrates the cover plate body (211) at both ends in the thickness direction of the cover plate (21). The pole post (22) includes a first pole post portion (221) and a second pole post portion (222). The first pole post portion (221) passes through the first connecting hole (212). The second pole post portion (222) is located on one side of the cover plate body (211) in the thickness direction of the cover plate (21). The second pole post portion (222) extends radially outward from the outer peripheral surface of the first pole post portion (221) toward the first connecting hole (212) and beyond the first connecting hole (212). The sealing ring (23) includes a first sealing part (2311) and a second sealing part (2312). The first sealing part (2311) is sleeved on the outer periphery of the first pole post (221) and extends into the first connecting hole (212). The second sealing part (2312) extends radially outward from the outer peripheral surface of the first sealing part (2311) toward the first connecting hole (212) and extends beyond the first connecting hole (212). The two ends of the second sealing part (2312) in the thickness direction of the cover plate (21) respectively abut against the cover plate body (211) and the second pole post (222). The second sealing part (2312) includes a pressing section (23121), the projection of the pressing section (23121) on the cover plate body (211) along the thickness direction of the cover plate (21) completely overlaps with the cover plate body (211); the thickness of the pressing section (23121) in the thickness direction of the cover plate (21) is defined as H, and the circumferential width of the pressing section (23121) in the radial direction of the cover plate (21) is defined as D; wherein, H / D < 0.

4.

2. The battery cover assembly as described in claim 1, characterized in that, The circumference D of the pressing section (23121) in the radial direction of the cover plate (21) ranges from 1.7mm to 3.5mm.

3. The battery cover assembly as described in claim 2, characterized in that, The circumference D of the pressing section (23121) in the radial direction of the cover plate (21) ranges from 2.5mm to 3.5mm.

4. The battery cover assembly as claimed in claim 1, characterized in that, The thickness H of the pressing section (23121) in the thickness direction of the cover plate (21) is less than the thickness of the cover plate body (211) in the thickness direction of the cover plate (21).

5. The battery cover assembly as described in claim 4, characterized in that, The thickness H of the pressing section (23121) in the thickness direction of the cover plate (21) ranges from 0.58mm to 0.82mm.

6. The battery cover assembly as claimed in claim 1, characterized in that, The diameter of the first connecting hole (212) is larger than the outer diameter of the first sealing part (2311).

7. The battery cover assembly as claimed in claim 1, characterized in that, The cover plate body (211) has an arc transition between the end face of the cover plate (21) in the thickness direction and the inner wall surface of the first connecting hole (212).

8. The battery cover assembly as claimed in claim 1, characterized in that, The sealing ring (23) has a second connecting hole (232) through which the pole post (22) passes, and the second connecting hole (232) extends through both ends of the cover plate (21) in the thickness direction; The electrode post (22) is a copper-aluminum composite electrode post, which includes a copper segment (223) and an aluminum segment (224). The junction of the copper segment (223) and the aluminum segment (224) is located inside the second connecting hole (232).

9. The battery cover assembly as claimed in claim 1, characterized in that, The sealing ring (23) is made of rubber.

10. A secondary battery, characterized in that, Includes the cover assembly of the battery as described in any one of claims 1 to 9.

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