Top cover for high sealing performance of secondary battery

Abstract

The utility model provides a top cover for high sealing performance of a secondary battery, which relates to the technical field of lithium batteries and comprises a cover plate, through-hole-shaped mounting holes formed in the left side and the right side, and a pole, an assembly structure is arranged at the outer end of the pole, the pole is fixedly mounted in the mounting holes through the assembly structure, and the assembly structure comprises an annular sealing ring, an aluminum ring and upper plastic, a step part is arranged at the outer end of the mounting hole, the outer diameter of the step part is larger than the inner diameter of the mounting hole, an outer contour part is arranged at the outer end of the pole, the outer diameter of the outer contour part is larger than the outer diameter of other positions of the pole, the position of the outer contour part corresponds to the step part, the sealing ring is mounted on the outer side of the outer contour part, and an inner concave groove is formed in the inner wall of the sealing ring to clamp the outer end of the outer contour part. When the aluminum ring is welded, the bottom face of the cover plate is not prone to being affected, the situation that the bottom face of the cover plate is perforated is avoided, the traditional bottom face welding position is adjusted to the top face welding position, and the risk of perforation air leakage can be reduced.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery technology, and more specifically, to a top cover for a secondary battery with high sealing performance. Background Technology

[0002] Lithium metal batteries typically use manganese dioxide as the positive electrode material, lithium metal or its alloys as the negative electrode material, and a non-aqueous electrolyte solution. The main function of the top cover and terminals of a lithium battery is to conduct electricity through the internal cells and prevent electrolyte leakage. The terminals are assembled with the top cover using sealing rings, plastic seals, aluminum rings, and other assembly structures. During battery use, if the sealing rings fail, there is a risk of electrolyte leakage, causing the battery to malfunction and even posing an explosion hazard.

[0003] For ease of manufacturing, the existing electrode posts have aluminum rings welded to them at the bottom of the top cover (e.g., ...). Figure 5 As shown, welding the aluminum ring to the top cover can easily damage the structure, leading to the risk of perforation and air leakage. Furthermore, the upper plastic in the top cover is made of PPS material, and the sealing ring is made of rubber material. During battery operation, these materials are prone to melting and deformation under high temperatures, resulting in changes in compression and causing adverse phenomena. Utility Model Content

[0004] The technical problem to be solved by this utility model is that welding the traditional aluminum ring to the top cover can easily damage the structure and cause the risk of perforation and air leakage. In view of the problems existing in the prior art, a top cover with high sealing performance for secondary batteries is provided.

[0005] The purpose and effect of this utility model are achieved by the following specific technical means: a top cover for high sealing performance of secondary batteries, comprising:

[0006] The cover plate has through-hole-shaped mounting holes on both the left and right sides;

[0007] The electrode post has an assembly structure at its outer end. The electrode post is fixedly installed in the mounting hole through the assembly structure. The assembly structure includes an annular sealing ring, an aluminum ring, and an upper plastic.

[0008] A further preferred embodiment: the outer end of the mounting hole is provided with a stepped portion, and the outer diameter of the stepped portion is larger than the inner diameter of the mounting hole.

[0009] A further preferred embodiment: the outer end of the pole post is provided with an outer contour portion, and the outer diameter of the outer contour portion is larger than the outer diameter of other positions of the pole post, and the position of the outer contour portion corresponds to the step portion.

[0010] A further preferred embodiment: the sealing ring is installed on the outer side of the outer contour, and the inner wall of the sealing ring is provided with a concave groove to hold the outer end of the outer contour.

[0011] A further preferred embodiment: the aluminum ring is disposed outside the sealing ring, and both the aluminum ring and the sealing ring are installed on the stepped portion, with the outer wall of the aluminum ring welded to the inner wall of the stepped portion.

[0012] A further preferred embodiment: the aluminum ring has a Z-shaped cross-section, and the inner diameter of the top of the aluminum ring is smaller than the outer diameter of the outer contour, with the top of the aluminum ring located above the outer contour;

[0013] The sealing ring is located between the aluminum ring and the outer contour.

[0014] A further preferred embodiment: there is a gap between the inner end of the sealing ring and the inner end of the aluminum ring and the pole post, and the upper plastic is located in this gap and wraps around the aluminum ring.

[0015] A further preferred embodiment: the bottom end of the step portion is at least 0.6 mm away from the bottom surface of the cover plate.

[0016] The beneficial effects of this utility model are:

[0017] The outer wall of the aluminum ring is tightly attached to the inner wall of the step. The outer wall of the aluminum ring is welded to the inner wall of the step to fix the aluminum ring and the cover plate as one piece. The bottom of the step and the bottom surface of the cover plate are at least 0.6mm apart. Because the cover plate is thicker than the bottom surface of the cover plate, the bottom surface of the cover plate is not easily affected when welding the aluminum ring, thus avoiding the situation of perforation of the bottom surface of the cover plate. Adjusting the traditional bottom surface welding position to the top surface welding can reduce the risk of perforation and air leakage.

[0018] Finally, PPS is injected onto the outside of the electrode post to form an upper plastic layer. Because there are gaps between the inner end of the sealing ring and the inner end of the aluminum ring and the electrode post, the upper plastic layer, after cooling and molding, is located in these gaps and wraps around the aluminum ring, completing the assembly. The upper plastic layer wraps around the welding position between the aluminum ring and the cover plate, which not only covers the welding marks and beautifies the appearance of the cover plate, but also increases the connection strength between the aluminum ring and the cover plate. The upper plastic layer located at the inner end of the sealing ring and the inner end of the aluminum ring can press down on the outer contour to fix the position of the electrode post.

[0019] When the sealing ring deforms due to the high temperature of the battery, there is an upper plastic block above the outer contour of the terminal post. Even if the upper plastic block deforms due to the high temperature, the terminal post can still prevent it from detaching after moving up to a certain position through the inner end of the aluminum ring, ensuring the connection between the terminal post and the top cover, playing a double protection role and avoiding adverse phenomena. Attached Figure Description

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 This is a front view of the overall structure of this utility model;

[0022] Figure 2 This is a partial structural front view of the present invention;

[0023] Figure 3 This utility model Figure 2 A magnified schematic diagram of the structure at point A in the diagram;

[0024] Figure 4 This is a disassembled schematic diagram of the cover plate, pole post, and assembly structure of this utility model.

[0025] Figure 5 This is a schematic diagram of the assembly of the top cover terminals of a traditional battery.

[0026] Figures 1-5 In the middle: cover plate (1), mounting hole (101), step part (102), sealing ring (2), aluminum ring (3), pole post (4), outer contour part (401), upper plastic (5). Detailed Implementation

[0027] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. The following embodiments are merely examples for implementing this utility model. It must be pointed out that the disclosed embodiments do not limit the scope of this utility model. On the contrary, any modifications and refinements made without departing from the scope of this utility model are within the patent protection scope of this utility model.

[0028] Please see Figures 1-4 A top cover for a high-sealing secondary battery, comprising:

[0029] The cover plate 1 has through-hole-shaped mounting holes 101 on the left and right sides. The cover plate 1 matches the square shell to form the housing of the square shell battery. In addition to the mounting holes 101, the cover plate 1 also has an explosion-proof port and an injection port. The explosion-proof port can release pressure when the battery pressure is too high, and the injection port can inject electrolyte into the battery housing.

[0030] The electrode post 4 has an assembly structure at its outer end. The electrode post 4 is fixedly installed in the mounting hole 101 through the assembly structure. The assembly structure includes an annular sealing ring 2, an aluminum ring 3, and an upper plastic 5.

[0031] The outer end of the pole post 4 is provided with an outer contour portion 401, and the outer diameter of the outer contour portion 401 is larger than the outer diameter of other positions of the pole post 4;

[0032] Installation steps for the assembly structure, pole post 4, and cover plate 1:

[0033] The inner wall of the sealing ring 2 has a concave groove that can hold the outer end of the outer contour 401. First, install the sealing ring 2 on the outside of the outer contour 401, with the concave groove holding the outer end of the outer contour 401. Then, lift the aluminum ring 3 and place it above the sealing ring 2. The pre-assembly of the pole post 4, sealing ring 2, and aluminum ring 3 is then completed. Finally, insert the three into the mounting hole 101. The height of the pole post 4 is greater than the thickness of the cover plate 1, so the bottom end of the pole post 4 can pass through the mounting hole 101 (e.g., Figure 2 As shown), so that the pole post 4 can be electrically connected to the connecting piece later. The outer end of the mounting hole 101 is provided with a stepped part 102. The outer diameter of the stepped part 102 is larger than the inner diameter of the mounting hole 101. The outer contour part 401 of the pole post 4, as well as the sealing ring 2 and the aluminum ring 3 are all located in the stepped part 102. The outer wall of the aluminum ring 3 is tightly attached to the inner wall of the stepped part 102. The outer wall of the aluminum ring 3 is welded to the inner wall of the stepped part 102. For the welding method, those skilled in the art can use methods such as laser welding or penetration welding to weld the aluminum ring 3 and the cover plate 1 together. The bottom end of the stepped part 102 is at least 0.6 mm away from the bottom surface of the cover plate 1. Because the cover plate 1 is thicker than the bottom surface of the cover plate 1, the bottom surface of the cover plate 1 is not easily affected when welding the aluminum ring 3, avoiding the situation of perforation of the bottom surface of the cover plate 1. Adjusting the traditional bottom surface welding position to the top surface welding can reduce the risk of perforation and air leakage.

[0034] Finally, PPS is injected onto the outside of the pole post 4 to form the upper plastic 5. Because there is a gap between the inner end of the sealing ring 2 and the inner end of the aluminum ring 3 and the pole post 4, the upper plastic 5, after cooling and forming, is located in this gap and wraps around the aluminum ring 3, completing the assembly. The upper plastic 5 wraps around the welding position between the aluminum ring 3 and the cover plate 1, which not only covers the welding marks and beautifies the appearance of the cover plate 1, but also increases the connection between the aluminum ring 3 and the cover plate 1. The upper plastic 5 located at the inner end of the sealing ring 2 and the inner end of the aluminum ring 3 can press down on the outer contour 401 to fix the position of the pole post 4.

[0035] like Figure 2 and Figure 3 The aluminum ring 3 has a Z-shaped cross-section, and the inner diameter of the top of the aluminum ring 3 is smaller than the outer diameter of the outer contour 401. The top of the aluminum ring 3 is located above the outer contour 401. The sealing ring 2 is located between the aluminum ring 3 and the outer contour 401. When the sealing ring 2 is deformed due to the high temperature of the battery, the upper plastic 5 on the outer contour 401 of the terminal post 4 will block it. Even if the upper plastic 5 is deformed due to the high temperature, the terminal post 4 can still be prevented from detaching through the inner end of the aluminum ring 3 after it moves up to a certain position, thus ensuring the connection between the terminal post 4 and the top cover and playing a double protection role to avoid adverse phenomena.

Claims

1. A top cover for a high-sealing secondary battery, characterized in that, include: The cover plate has through-hole-shaped mounting holes on both the left and right sides. The outer end of the mounting hole has a stepped part, and the outer diameter of the stepped part is larger than the inner diameter of the mounting hole. The pole has an assembly structure at its outer end, and the pole is fixedly installed in the mounting hole through the assembly structure. The outer end of the pole has an outer contour portion, and the outer diameter of the outer contour portion is larger than the outer diameter of other positions of the pole. The position of the outer contour portion corresponds to the step portion. The assembly structure includes an annular sealing ring, an aluminum ring, and an upper plastic layer. The sealing ring is installed on the outer side of the outer contour, and the inner wall of the sealing ring has a concave groove to hold the outer end of the outer contour. The aluminum ring is set on the outer side of the sealing ring, and both the aluminum ring and the sealing ring are installed on the stepped portion. The outer wall of the aluminum ring is welded to the inner wall of the stepped portion. The aluminum ring has a Z-shaped cross-section, and the inner diameter of the top of the aluminum ring is smaller than the outer diameter of the outer contour. The top of the aluminum ring is located above the outer contour. The sealing ring is located between the aluminum ring and the outer contour.

2. The top cover for a high-sealing secondary battery according to claim 1, characterized in that: There is a gap between the inner end of the sealing ring and the inner end of the aluminum ring and the pole post, and the upper plastic is located in this gap and wraps around the aluminum ring.

3. The top cover for a high-sealing secondary battery according to claim 2, characterized in that: The distance between the bottom end of the step and the bottom surface of the cover plate is at least 0.6 mm.

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