Sealing nail with pressure relief function, cover plate assembly and battery cell

Abstract

The utility model discloses a sealing nail with a pressure relief function, a cover plate assembly and a battery cell, the sealing nail comprises a rubber nail and a sealing nail main body, and the rubber nail is used for being plugged in a liquid injection hole in a cover plate of the battery cell; the sealing nail body fixedly covers the outer edge of the liquid injection hole, a pressure relief nick is formed in the end face, close to the inner side of the liquid injection hole, of the sealing nail body, and the depth of the pressure relief nick is smaller than the thickness of the sealing nail body. The sealing nail structure has the beneficial effects that a battery cell made of the sealing nail structure in the technical scheme has a liquid injection hole sealing function and a battery cell pressure relief function at the same time, so that direct contact between electrolyte and the sealing nail main body can be avoided, and the safety problem of the battery cell caused by corrosion of the electrolyte to the sealing nail main body is prevented; and the number of battery cell parts can be reduced, the processing and assembling procedures are optimized, the production efficiency is improved, and the production cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and in particular to a sealing nail, a cover plate assembly and a battery core with a pressure relief function. Background Art

[0002] Currently, most battery cells have two functional structures: liquid injection and pressure relief, and are generally arranged on the cover assembly. Among them, the pressure relief valve, as a separate component, needs to be welded to the top cover in advance and tested for airtightness before a protective sheet is attached. Generally, the pressure relief valve and the protective sheet must not protrude from the front and back of the top cover. This requires the design of a recessed step on both sides of the pressure relief structure on the top cover to allow the pressure relief valve and the protective sheet to sink into the top cover during assembly to prevent them from protruding from the front and back surfaces. At the same time, after the battery cell is injected, a sealing pin needs to be welded to the injection structure to seal the battery cell. Generally, the sealing pin is required to sink into the top cover, and the top cover structure here also needs to be designed with a recessed step.

[0003] In this design, the cover plate assembly has many parts, the single top cover plate has many processing steps, and the assembly is complicated, there are many risk control points, the production efficiency is low, and the production cost is high. Utility Model Content

[0004] The purpose of this utility model is to overcome the above-mentioned technical deficiencies and propose a sealing nail, cover plate assembly and battery cell with a pressure relief function, so as to solve the technical problems in the prior art that the cover plate assembly has many parts, the single top cover plate has many processing steps, the assembly is complex, there are many risk control points, the production efficiency is low and the production cost is high.

[0005] In order to achieve the above technical objectives, the present invention adopts the following technical solutions:

[0006] The utility model provides a sealing nail with a pressure relief function, comprising:

[0007] A plastic nail, which is used to plug the liquid injection hole on the cover of the battery cell; and

[0008] The sealing nail body, wherein the fixing cover of the sealing nail body is arranged on the outer edge of the liquid injection hole, and a pressure relief notch is provided on the inner end face of the sealing nail body close to the liquid injection hole, and the depth of the pressure relief notch is less than the thickness of the sealing nail body. When the pressure applied to the sealing nail body exceeds the preset pressure, the sealing nail body can be broken along the pressure relief notch.

[0009] In some embodiments, a first recessed groove is formed on the outer edge of the liquid injection hole, and the sealing nail body is fixed in the first recessed groove.

[0010] In some embodiments, the sealing nail body includes an annular portion and a pressure relief portion, the annular portion is fixedly attached to the inner wall of the first groove, the pressure relief portion is formed at the center of the annular portion, and the pressure relief notch is opened in the pressure relief portion.

[0011] In some embodiments, the outer edge of the pressure relief portion has a circular contour, the pressure relief notch is opened on the outer edge of the pressure relief portion, and the length of the pressure relief notch accounts for 7 / 8 to 9 / 10 of the circumference of the outer edge of the pressure relief portion.

[0012] In some embodiments, the annular portion is welded to the inner wall of the first sink.

[0013] In some embodiments, the sealing pin further includes a protective sheet, which is fixed to the annular portion. The protective sheet is covered above the pressure relief portion, and an air hole is provided at the center of the protective sheet.

[0014] In some embodiments, a second recessed groove is formed on the upper surface of the annular portion, and the protective sheet is embedded in the second recessed groove.

[0015] The utility model also provides a cover plate assembly, comprising a cover plate and the sealing nail with the pressure relief function.

[0016] In some embodiments, a cap is further formed at the center of the cover plate.

[0017] The utility model also provides a battery core, comprising a cover plate and the sealing nail with the pressure relief function.

[0018] Compared with the prior art, the beneficial effect of the present invention is that it is only necessary to design an injection hole on the cover plate of the battery cell, and after the battery cell is assembled and injected, a glue nail is inserted, and then a sealing nail body is placed on the outer edge of the injection hole, and the sealing nail body is welded to the outer edge of the injection hole. Therefore, the present technical solution does not need to process a groove on the cover plate to stick a protective sheet. The battery cell made of the sealing nail structure of the present technical solution has both the sealing function of the injection hole and the pressure relief function of the battery cell. At the same time, since the injection hole is sealed by the glue nail, direct contact between the electrolyte and the sealing nail body can be avoided, and the electrolyte can be prevented from corroding the sealing nail body and causing safety problems of the battery cell; the present technical solution has a simple structure, can reduce the number of battery cell parts, optimize the processing and assembly procedures, reduce process risk control points, improve production efficiency, and reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is an exploded view of a sealing pin with a pressure relief function and a corresponding cover plate assembly provided by one embodiment of the present invention;

[0020] Figure 2 yes Figure 1A schematic structural diagram of a sealing pin with a pressure relief function and a corresponding cover plate assembly;

[0021] Figure 3 yes Figure 2 A schematic structural diagram of the sealing nail body;

[0022] Explanation of the accompanying drawings: 1-sealing pin, 11-glue pin, 12-sealing pin body, 121-pressure relief notch, 122-annular portion, 1221-second sink groove, 123-pressure relief portion, 13-protective sheet, 131-air hole, 2-cover plate, 21-liquid injection hole, 22-first sink groove, 23-cap. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] In order to solve the technical problems of many parts in the cover assembly, many processing steps for a single top cover piece, complex assembly, many risk control points, low production efficiency and high production cost, the utility model provides a sealing nail, a cover assembly and a battery cell with a pressure relief function, which can reduce the number of parts of the cover assembly, reduce assembly complexity, improve production efficiency and reduce production costs.

[0025] See also Figure 1 , Figure 1 This is an exploded view of a sealing nail 1 with a pressure relief function and a corresponding cover plate assembly in an embodiment of the present invention. The sealing nail 1 with a pressure relief function includes a glue nail 11 and a sealing nail body 12 .

[0026] See also Figure 1 and Figure 2 The plastic nail 11 is used to plug the liquid injection hole 21 on the cover plate 2 of the battery cell. The material of the plastic nail 11 can be a retractable rubber material.

[0027] The sealing nail body 12 is fixedly covered on the outer edge of the liquid injection hole 21, and a pressure relief notch 121 is provided on the inner end face of the sealing nail body 12 close to the liquid injection hole 21. The depth of the pressure relief notch 121 is less than the thickness of the sealing nail body 12, so that the pressure relief notch 121 will not cause the sealing nail body 12 to break under normal conditions. When the pressure on the sealing nail body 12 exceeds the preset pressure, the sealing nail body 12 can break along the pressure relief notch 121. This is because the structural strength of the sealing nail body 12 at the pressure relief notch 121 is lower than that of other parts due to the existence of the pressure relief notch 121. Therefore, when the internal pressure of the battery cell is too high, the glue nail 11 will be pushed out first, and then the high-pressure fluid will contact the sealing nail body 12. When the pressure on the sealing nail body 12 exceeds the preset pressure, the sealing nail body 12 can break along the pressure relief notch 121.

[0028] The technical solution provided by the present invention only requires designing a liquid injection hole 21 on the cover plate 2 of the battery cell. After the battery cell is assembled and injected with liquid, the glue nail 11 is inserted, and then the sealing nail body 12 is placed on the outer edge of the liquid injection hole 21, and the sealing nail body 12 is welded to the outer edge of the liquid injection hole 21. Therefore, the present technical solution does not need to process a groove on the cover plate 2 to stick a protective sheet. The battery cell made of the sealing nail structure of the present technical solution has both the sealing function of the liquid injection hole 21 and the pressure relief function of the battery cell. At the same time, since the liquid injection hole 21 is sealed by the glue nail 11, direct contact between the electrolyte and the sealing nail body 12 can be avoided, and the electrolyte can be prevented from corroding the sealing nail body 12 and causing safety problems of the battery cell; the present technical solution has a simple structure, can reduce the number of battery cell parts, optimize the processing and assembly processes, reduce process risk control points, improve production efficiency, and reduce production costs.

[0029] In one embodiment, see Figure 1 and Figure 2 A first recessed groove 22 is formed on the outer edge of the liquid injection hole 21 , and the sealing nail body 12 is fixed in the first recessed groove 22 .

[0030] In one embodiment, see Figure 1-Figure 3 The sealing nail body 12 includes an annular portion 122 and a pressure relief portion 123. The annular portion 122 is fixedly attached to the inner wall of the first sink groove 22. The pressure relief portion 123 is formed at the center of the annular portion 122. The pressure relief notch 121 is opened in the pressure relief portion 123.

[0031] In one embodiment, see Figure 1-Figure 3The outer edge of the pressure relief portion 123 is circular, and the pressure relief notch 121 is located on the outer edge of the pressure relief portion 123. The length of the pressure relief notch 121 accounts for 7 / 8 to 9 / 10 of the outer circumference of the pressure relief portion 123. During use, if the internal pressure of the battery cell is too high, the pressure relief portion 123 explodes at the location of the pressure relief notch 121, leaving the remaining unnotched area. This allows the pressure relief portion 123 to remain on the annular portion 122 after the explosion, preventing it from splashing outward and posing a safety risk.

[0032] In one embodiment, see Figure 1-Figure 3 The annular portion 122 is welded to the inner wall of the first sink 22 .

[0033] In one embodiment, see Figure 1-Figure 3 The sealing nail 1 also includes a protective sheet 13, which is fixed to the annular portion 122. The protective sheet 13 is covered above the pressure relief portion 123. An air hole 131 is opened in the center of the protective sheet 13. When in use, when the pressure relief portion 123 explodes, high-pressure fluid can be discharged from the air hole 131.

[0034] In one embodiment, see Figure 1-Figure 3 A second recessed groove 1221 is formed on the upper surface of the annular portion 122 , and the protective sheet 13 is embedded in the second recessed groove 1221 , so that the protective sheet 13 does not protrude from the surface of the cover plate 2 .

[0035] The utility model also provides a cover plate assembly, comprising a cover plate 2 and a sealing nail 1 with a pressure relief function.

[0036] In one embodiment, see Figure 1 A cap 23 is also formed in the center of the cover plate 2.

[0037] The utility model also provides a battery core, comprising a cover plate 2 and a sealing nail 1 with a pressure relief function.

[0038] In order to better understand the present invention, the following Figures 1 to 3The technical solution of the present invention is described in detail: after the battery cell is assembled and injected with liquid, the glue nail 11 is inserted, and then the sealing nail body 12 is placed on the outer edge of the injection hole 21, and the sealing nail body 12 is welded to the outer edge of the injection hole 21, and finally the protective sheet 13 is pasted in the second groove 1221. Therefore, the present technical solution does not need to process a groove on the cover plate 2 to paste the protective sheet. The battery cell made of the sealing nail structure of the present technical solution has both the sealing function of the injection hole 21 and the pressure relief function of the battery cell. At the same time, since the injection hole 21 is sealed by the glue nail 11, direct contact between the electrolyte and the sealing nail body 12 can be avoided, and the electrolyte can be prevented from corroding the sealing nail body 12 and causing safety problems of the battery cell; the present technical solution has a simple structure, can reduce the number of battery cell parts, optimize the processing and assembly processes, reduce process risk control points, improve production efficiency, and reduce production costs.

[0039] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A sealing nail with a pressure relief function, characterized in that: include: A plastic nail, which is used to plug the liquid injection hole on the cover of the battery cell; and The sealing nail body, wherein the fixing cover of the sealing nail body is arranged on the outer edge of the liquid injection hole, and a pressure relief notch is provided on the inner end face of the sealing nail body close to the liquid injection hole, and the depth of the pressure relief notch is less than the thickness of the sealing nail body. When the pressure applied to the sealing nail body exceeds the preset pressure, the sealing nail body can be broken along the pressure relief notch.

2. The sealing nail with pressure relief function according to claim 1, characterized in that: A first recessed groove is formed on the outer edge of the liquid injection hole, and the sealing nail body is fixed in the first recessed groove.

3. The sealing nail with pressure relief function according to claim 2, characterized in that: The sealing nail body includes an annular portion and a pressure relief portion. The annular portion is fixedly attached to the inner wall of the first sink groove. The pressure relief portion is formed at the center of the annular portion. The pressure relief notch is opened in the pressure relief portion.

4. The sealing nail with pressure relief function according to claim 3, characterized in that: The outer edge of the pressure relief portion has a circular outline, the pressure relief notch is opened on the outer edge of the pressure relief portion, and the length of the pressure relief notch accounts for 7 / 8 to 9 / 10 of the circumference of the outer edge of the pressure relief portion.

5. The sealing nail with pressure relief function according to claim 3, characterized in that: The annular portion is welded to the inner side wall of the first sink.

6. The sealing nail with pressure relief function according to claim 3, characterized in that: The sealing nail further comprises a protective sheet, which is fixed to the annular portion and is covered on top of the pressure relief portion. An air hole is provided at the center of the protective sheet.

7. The sealing nail with pressure relief function according to claim 6, characterized in that: A second recessed groove is formed on the upper surface of the annular portion, and the protection sheet is embedded in the second recessed groove.

8. A cover plate assembly, characterized in that: It comprises a cover plate and a sealing nail with a pressure relief function as claimed in any one of claims 1 to 7.

9. The cover plate assembly according to claim 8, wherein: A cover cap is also formed at the center of the cover plate.

10. A battery cell, characterized in that: It comprises a cover plate and a sealing nail with a pressure relief function as claimed in any one of claims 1 to 7.

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