Top cover for secondary battery

Abstract

The utility model provides a top cover for a secondary battery, which is characterized in that a top cover plate is provided with a pole hole, a pole is provided with a step surface, the pole penetrates through the pole hole of the top cover plate, a sealing ring is arranged between the pole and the top cover plate, the bottom of a metal ring is matched and assembled with the step of the pole hole of the top cover plate, and the surface of the outer side wall of the metal ring is provided with a plurality of blind holes. Upper plastic cement is injection-molded on the pole and the metal ring in a surrounding manner; the blind hole with a certain depth is formed in the outer side wall of the metal ring, on one hand, in the injection molding process, residual metal filings or metal wires can only reach the blind hole along with flowing plastic, and it is effectively avoided that the metal filings or the metal wires are wrapped by the metal filings or the metal wire plastic to be converged to the joint of the sealing ring and the upper plastic; poor insulation is generated between the pole and the top cover plate; on the other hand, the plastic is injected into the blind hole of the metal ring, so that the fastening among the plastic, the metal ring and the pole is improved, the push-pull resistance of the pole of the top cover is improved, and the safety and reliability of the battery are finally improved.

Description

Technical Field

[0001] The utility model relates to the field of lithium-ion batteries, in particular to a top cover for secondary batteries. Background Art

[0002] With the development of new energy, the existing batteries have further increased requirements for energy density. New energy power batteries are usually secondary batteries, which refer to batteries that can activate active substances and continue to be used through charging after discharging.

[0003] As the main power source of new energy vehicles, power batteries have become one of the key components of electric vehicles. In the existing technology of the top cover of square batteries, an aluminum ring is welded on the top cover. Since several holes are provided on the side of the aluminum ring, this aluminum ring structure belongs to special-shaped punching with holes, which will generate a large amount of metal chips and metal wires. The existing cleaning technology cannot completely remove them. During the process of plastic injection molding, the metal chips will be carried and converge at the joint of the sealing ring and the upper plastic, resulting in poor insulation between the pole column and the top cover plate, and there is a risk of battery failure.

[0004] Therefore, we propose a top cover for secondary batteries to solve the above problems. Content of the Utility Model

[0005] The purpose of the utility model is to solve the disadvantages existing in the prior art. To achieve the above purpose, the utility model adopts the following technical scheme:

[0006] A top cover for secondary batteries, comprising a top cover sheet, a sealing ring, a pole column, a metal ring and an upper plastic; a pole column hole is provided on the top cover sheet, the pole column has a stepped surface, the pole column penetrates through the pole column hole of the top cover sheet, the sealing ring is arranged between the pole column and the top cover sheet, the bottom of the metal ring is assembled in cooperation with the stepped part of the pole column hole of the top cover sheet, several blind holes are opened on the outer surface of the outer side wall of the metal ring, and the upper plastic is injection-molded around the pole column and the metal ring.

[0007] Further preferably, the blind holes penetrate through the outer surface of the side wall of the metal ring, and the depth of the blind holes is 0.1-0.9 times the wall thickness of the metal ring.

[0008] Further preferably, the blind holes are any one of circular, rectangular, triangular and oval.

[0009] Further preferably, a lower plastic is assembled at the bottom end of the top cover sheet, and a plurality of fixing buckles are arranged on both sides of the top end of the lower plastic.

[0010] Further preferably, fixing holes are provided at the bottom end of the top cover sheet to cooperate with the fixing buckles on the lower plastic.

[0011] Further preferably, an explosion-proof valve is provided on the through hole of the top cover sheet, and a protective film is provided at the top end of the explosion-proof valve.

[0012] Further preferably, the metal ring is an aluminum ring, and the metal ring is fixedly welded to the top cover sheet.

[0013] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0014] In the present utility model, by providing blind holes with a certain depth on the outer side wall of the metal ring, on the one hand, during the injection molding process, residual metal chips or metal wires can only reach the blind holes along with the flowing plastic, effectively preventing the plastic from carrying metal chips or metal wires and converging at the joint between the sealing ring and the upper plastic, thus avoiding poor insulation between the pole column and the top cover plate; on the other hand, by injecting plastic into the blind holes of the metal ring, the fastening between the plastic, the metal ring, and the pole column is increased, thereby enhancing the anti-pushing and pulling force of the top cover pole column, and ultimately improving the safety and reliability of the battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an exploded view of the present utility model;

[0016] Figure 2 is an assembly view of the present utility model;

[0017] Figure 3 is a cross-sectional view of the present utility model;

[0018] Figure 4 is a structural view of the metal ring;

[0019] Figure 5 is a cross-sectional view of the metal ring.

[0020] In the figure: top cover sheet 1, sealing ring 2, pole column 3, metal ring 4, upper plastic 5, explosion-proof valve 6, protective film 7, lower plastic 8, blind hole 41. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments.

[0022] Refer to Figures 1 - 5A top cover for a secondary battery comprises a top cover sheet 1, a sealing ring 2, a pole 3, a metal ring 4 and an upper plastic 5; the top cover sheet 1 is provided with a pole hole, the pole 3 has a step surface, the pole 3 is passed through the pole hole of the top cover sheet 1, the sealing ring 2 is arranged between the pole 3 and the top cover sheet 1, the bottom of the metal ring 4 is matched and assembled with the step of the pole hole of the top cover sheet 1, a plurality of blind holes 41 are opened on the outer wall surface of the metal ring 4, and the pole 3 and the metal ring 4 are surrounded by injection molding with an upper plastic 5.

[0023] By setting a blind hole 41 of a certain depth on the outer wall of the metal ring 4, the blind hole 41 is a non-through hole that penetrates the outer surface of the side wall of the metal ring 4. During the injection molding process, the residual metal chips or metal wires can only reach the blind hole 41 with the flowing plastic. Since the blind hole 41 does not penetrate the side wall of the metal ring 4, it effectively prevents the plastic from entraining the metal chips or metal wires and gathering at the junction of the sealing ring and the upper plastic, causing poor insulation between the pole 3 and the top cover sheet 1. On the other hand, by injecting plastic into the blind hole 41 of the metal ring, the fastening between the plastic, the metal ring and the pole is increased, the push-pull resistance of the top cover pole is improved, and finally the safety and reliability of the battery is improved.

[0024] The blind hole 41 passes through the outer surface of the side wall of the metal ring 4 , and the depth of the blind hole 41 is 0.1-0.9 times the wall thickness of the metal ring 4 ; the blind hole 41 is any one of circular, rectangular, triangular and elliptical.

[0025] In the embodiment, the blind hole 41 is a circular blind hole, and three blind holes are arranged on each side wall of the metal ring 4; the blind holes are symmetrically distributed; the depth of the blind holes is 0.8 mm, and the wall thickness of the metal ring is 1 mm.

[0026] In the embodiment: the blind hole 41 is a circular blind hole and an elliptical blind hole, and two blind holes are arranged on each side wall of the metal ring 4; the blind holes are asymmetrically distributed; the circular and elliptical blind holes are adjacent; the blind hole depth is 0.5 mm, and the metal ring wall thickness is 1.5 mm.

[0027] In the embodiment: the blind hole 41 is a circular, rectangular or elliptical blind hole, and three blind holes are arranged on each side wall of the metal ring 4; the blind holes are symmetrically distributed; the blind holes are circular, rectangular and elliptical in sequence; the blind hole depth is 0.6 mm, and the metal ring wall thickness is 1.2 mm.

[0028] The bottom end of the top cover sheet 1 is equipped with a lower plastic 8 , and a plurality of fixing buckles are arranged on both sides of the top end of the lower plastic 8 ; the bottom end of the top cover sheet 1 is provided with a fixing hole that matches with the fixing buckle on the lower plastic 8 .

[0029] In the embodiment: a plurality of fixing buckle structures are provided on both sides of the top end of the lower plastic 8, and a fixing hole is provided at the bottom end of the top cover sheet 1 to cooperate with the fixing buckle on the lower plastic 8. The top cover sheet 1 and the lower plastic 8 are installed by first assembling them into place through the fixing buckles and the fixing holes, and then assembling the top cover sheet 1 and the lower plastic 8. The assembly method is snap-fit ​​or ultrasonic hot melting. Preferably, the top cover sheet 1 and the lower plastic 8 are assembled by ultrasonic hot melting.

[0030] An explosion-proof valve 6 is provided on the through hole of the top cover sheet 1 , and a protection mold 7 is provided on the top end of the explosion-proof valve 6 .

[0031] In the embodiment: a through hole is provided in the middle of the top cover sheet 1 for assembling and welding the explosion-proof valve 6. A protective mold 7 is provided on the explosion-proof valve 6, and the protective mold 7 is pasted on the top of the explosion-proof valve 6. The explosion-proof valve 6 can break when the internal pressure of the battery cell reaches a critical point, which can effectively prevent the battery cell from exploding due to excessive pressure. At the same time, the protective mold 7 can protect the explosion-proof valve 6 from the outside, which can effectively prevent the explosion-proof valve 6 from being affected by the outside.

[0032] The metal ring 4 is an aluminum ring, and the metal ring 4 is fixed to the top cover sheet 1 by welding.

[0033] In the embodiment, the top cover sheet 1 and the metal ring 4 are both aluminum rings, the top cover sheet 1 and the metal ring 4 are through-welded, and the welding point is located at the bottom surface of the top cover sheet 1 .

[0034] The utility model provides a blind hole of a certain depth on the outer wall of the metal ring. On the one hand, during the injection molding process, the residual metal chips or metal wires can only reach the blind hole with the flowing plastic, which effectively prevents the plastic from enveloping the metal chips or metal wires and converging at the junction of the sealing ring and the upper plastic, causing poor insulation between the pole and the top cover plate; on the other hand, the plastic is injected into the blind hole of the metal ring to increase the fastening between the plastic, the metal ring and the pole, thereby improving the push-pull resistance of the top cover pole, and ultimately improving the safety and reliability of the battery.

Claims

1. A top cover for a secondary battery, characterized in that, It includes a top cover sheet, a sealing ring, a terminal post, a metal ring and upper plastic; a terminal post hole is provided on the top cover sheet, the terminal post has a stepped surface, the terminal post passes through the terminal post hole of the top cover sheet, the sealing ring is arranged between the terminal post and the top cover sheet, the bottom of the metal ring is fitted and assembled with the stepped part of the terminal post hole of the top cover sheet, several blind holes are provided on the outer surface of the side wall of the metal ring, and the terminal post and the metal ring are injection-molded with upper plastic around them.

2. The top cover for a secondary battery according to claim 1, characterized in that, The blind holes penetrate the outer surface of the side wall of the metal ring, and the depth of the blind holes is 0.1-0.9 times the wall thickness of the metal ring.

3. The top cover for a secondary battery according to claim 1, characterized in that, The blind holes are any one of circular, rectangular, triangular and oval.

4. The top cover for a secondary battery according to claim 1, wherein A lower plastic is assembled at the bottom end of the top cover sheet, and a plurality of fixing buckles are provided on both sides of the top end of the lower plastic.

5. The top cover for a secondary battery according to claim 4, characterized in that, Fixing holes are provided at the bottom end of the top cover sheet to cooperate with the fixing buckles on the lower plastic.

6. The top cover for a secondary battery according to claim 1, wherein, An explosion-proof valve is provided on the through hole of the top cover sheet, and a protection mold is provided at the top end of the explosion-proof valve.

7. The top cover for a secondary battery according to claim 1, characterized in that, The metal ring is an aluminum ring, and the metal ring is fixedly welded to the top cover sheet.

Images