Secondary battery top cover

Abstract

The utility model provides a secondary battery top cover, a top cover sheet is provided with a first plane and a second plane which are arranged back to back along the thickness direction of the top cover sheet, the first plane is provided with a first groove, the bottom surface of the first groove is an inclined surface, the second plane is provided with a first bulge, the first groove is internally provided with a second groove, and the second groove is internally provided with a second bulge. A second protrusion is arranged on the surface of the first protrusion, and a first liquid injection hole penetrating through the second protrusion is formed in the surface of the second groove. The lower plastic is assembled on the bottom surface of the top cover sheet, a third groove is formed in the upper surface of the lower plastic, and a fourth groove is formed in the bottom surface of the third groove; according to the cover plate mechanism, the first groove is formed in the upper surface of the top cover piece, and overflowed electrolyte is stored through the first groove, so that the electrolyte is prevented from flowing into the anti-explosion valve, the phenomena that the anti-explosion valve is polluted, corroded and the like are avoided, the service life of the anti-explosion valve is prolonged, and the use safety of the cover plate mechanism is improved.

Description

Technical Field

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

[0002] Power batteries generally include a metal shell, battery cells arranged inside the metal shell, and a cover plate assembly arranged at the top of the metal shell and electrically connected to the battery cells. Positive and negative electrode tabs are provided on the battery cells, and the cover plate assembly includes a metal cover plate, a lower plastic part fixed to the bottom of the metal cover plate, and a positive electrode post and a negative electrode post arranged on the metal cover plate. At the same time, a liquid injection hole and an explosion-proof valve are also arranged on the cover plate assembly to meet the requirements of liquid injection and explosion prevention of the power battery.

[0003] During the processing of power batteries, a liquid injection operation is required. During the liquid injection process, first, electrolyte needs to be injected into the inside of the shell through the liquid injection hole provided on the cover plate assembly. During the liquid injection process, the electrolyte often overflows and flows into the explosion-proof valve, thereby corroding the notch of the explosion-proof valve, resulting in battery failure of the battery cells during the production line or shortly after sale.

[0004] Therefore, we propose a top cover of a secondary battery to solve the problem of electrolyte overflowing and flowing into the explosion-proof valve. Content of the Utility Model

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

[0006] A top cover of a secondary battery, comprising: a top cover sheet, two opposite first plane and second plane are arranged on the top cover sheet along its thickness direction, a first groove is arranged on the first plane, the bottom surface of the first groove is an inclined surface, a first protrusion is arranged on the second plane, a second groove is arranged in the first groove, a second protrusion is arranged on the surface of the first protrusion, and a first liquid injection hole penetrating through the second protrusion is arranged on the surface of the second groove; a lower plastic part, which is assembled on the bottom surface of the top cover sheet, a third groove is arranged on the upper surface of the lower plastic part, a fourth groove is arranged on the bottom surface of the third groove, and a second liquid injection hole penetrating through is arranged in the fourth groove.

[0007] Further preferably, a waist-shaped hole is arranged on the surface of the top cover sheet, and the depth of the bottom surface of the first groove near the waist-shaped hole is less than the depth of the bottom surface of the first groove far from the waist-shaped hole.

[0008] Further preferably, several through-flow guiding grooves are evenly distributed on the side wall of the fourth groove.

[0009] Further preferably, the depth of the third groove is greater than the height of the first protrusion, and the inner diameter of the third groove is greater than the outer diameter of the first protrusion.

[0010] Further preferably, the depth of the fourth groove is greater than the height of the second protrusion, and the inner diameter of the fourth groove is greater than the outer diameter of the second protrusion.

[0011] Further preferably, an explosion-proof valve and a protection piece are installed on the waist-shaped hole.

[0012] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0013] By providing a first groove on the upper surface of the top cover sheet, the present utility model stores the overflowing electrolyte through the first groove, thereby preventing the electrolyte from flowing into the explosion-proof valve, avoiding phenomena such as pollution and corrosion of the explosion-proof valve, and further prolonging the service life of the explosion-proof valve and improving the use safety of the cover mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 is an exploded view of the top cover sheet and the lower plastic in the present utility model;

[0015] Figure 2 is a cross-sectional view of the top cover sheet of the present utility model;

[0016] Figure 3 is an exploded view of the present utility model;

[0017] Figure 4 is an assembled structural view of the present utility model.

[0018] In the figure: top cover sheet 1, lower plastic 2, first groove 11, second groove 12, first liquid injection hole 13, first protrusion 14, second protrusion 15, waist-shaped hole 16, third groove 21, fourth groove 22, second liquid injection hole 23, explosion-proof valve 7, protection piece 8. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] The technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to 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.

[0020] Refer to Figures 1 - 4, A secondary battery top cover, comprising: a top cover sheet 1, two opposite first plane and second plane are arranged along the thickness direction of the top cover sheet 1, a first groove 11 is arranged on the first plane, the bottom surface of the first groove 11 is an inclined surface, a first protrusion 14 is arranged on the second plane, a second groove 12 is arranged in the first groove 11, a second protrusion 15 is arranged on the surface of the first protrusion 14, and a first liquid injection hole 13 penetrating through the second protrusion 15 is arranged on the surface of the second groove 12; a lower plastic 2, the lower plastic 2 is assembled on the bottom surface of the top cover sheet 1, a third groove 21 is arranged on the upper surface of the lower plastic 2, a fourth groove 22 is arranged on the bottom surface of the third groove 21, and a second liquid injection hole 23 penetrating through is arranged in the fourth groove 22.

[0021] In the embodiment: The lower plastic 2 is assembled on the bottom surface of the top cover sheet 1. The third groove 21 and the fourth groove 22 on the lower plastic 2 are respectively used to avoid the first protrusion 14 and the second protrusion 15 on the top cover sheet 1. The electrolyte is injected into the battery cell from the first liquid injection hole 13 and the second liquid injection hole 23 in sequence. When a small amount of electrolyte overflows from the first liquid injection hole 13, the overflowing electrolyte is stored through the first groove 11, thereby preventing the electrolyte from flowing into the explosion-proof valve, avoiding phenomena such as pollution and corrosion of the explosion-proof valve, and further prolonging the service life of the explosion-proof valve and improving the use safety of the cover mechanism.

[0022] In the embodiment: The first groove 11 and the first protrusion 14 of the top cover sheet 1 are formed by cold heading process, the second groove 12 and the second protrusion 15 are formed by cold heading process. The grooves and protrusions formed by the cold heading process play a role in locally strengthening the top cover sheet. The height between the first plane and the bottom surface of the second protrusion 15 is 0 - 5 mm, which can be 1, 2, 3, 4 or other values between 0 - 5 mm; the diameter of the first groove 11 is 1 - 50 mm, which can be 5, 10, 15, 20, 25, 30, 35, 40, 45 or other values between 1 - 50 mm.

[0023] A waist-shaped hole 16 is arranged on the surface of the top cover sheet 1, and the depth of the bottom surface of the first groove 11 near the waist-shaped hole 16 is less than the depth of the bottom surface of the first groove 11 far from the waist-shaped hole 16.

[0024] In the embodiment: The bottom surface of the first groove 11 is an inclined surface, the side near the waist-shaped hole 16 is higher than the side far from the waist-shaped hole 16, so that the electrolyte stored in the first groove 11 flows to the side far from the waist-shaped hole 16, further preventing the electrolyte from flowing into the explosion-proof valve and avoiding phenomena such as pollution and corrosion of the explosion-proof valve.

[0025] In the embodiment: The depth of the bottom surface of the first groove 11 on the side near the waist-shaped hole 16 is 0.1 - 1.5 mm, and the depth of the bottom surface of the first groove 11 on the side far from the waist-shaped hole 16 is 0.5 - 2 mm.

[0026] In one embodiment: the depth of the bottom surface of the first groove 11 on one side close to the kidney-shaped hole 16 is 1.0 mm, and the depth of the bottom surface of the first groove 11 far from the kidney-shaped hole 16 is 2.0 mm.

[0027] In another embodiment: the depth of the bottom surface of the first groove 11 on one side close to the kidney-shaped hole 16 is 0.5 mm, and the depth of the bottom surface of the first groove 11 far from the kidney-shaped hole 16 is 1.5 mm.

[0028] A plurality of through-flow guiding grooves are evenly distributed on the side walls of the fourth groove 22.

[0029] In the embodiment: when injecting liquid into the battery cell, the flow guiding grooves can accelerate the inflow speed of the electrolyte, thereby improving the liquid injection efficiency.

[0030] The depth of the third groove 21 is greater than the height of the first protrusion 14, and the inner diameter of the third groove 21 is greater than the outer diameter of the first protrusion 14; the depth of the fourth groove 22 is greater than the height of the second protrusion 15, and the inner diameter of the fourth groove 22 is greater than the outer diameter of the second protrusion 15.

[0031] In the embodiment: when assembling the lower plastic 2 and the top cover piece 1, the third groove 21 and the fourth groove 22 of the lower plastic 2 will not interfere with the first protrusion 14 and the second protrusion 15 on the top cover piece 1.

[0032] An explosion-proof valve 7 and a protection piece 8 are installed on the kidney-shaped hole 16.

[0033] In the embodiment: the kidney-shaped hole 16 is used for assembling the explosion-proof valve 7, a protection piece 8 is provided on the explosion-proof valve 7, the explosion-proof valve 7 can break when the internal pressure of the battery cell reaches the critical point, which can effectively prevent the battery cell from exploding due to excessive pressure inside, and at the same time the protection piece 8 can protect the explosion-proof valve 7 externally, which can effectively prevent the explosion-proof valve 7 from being affected externally.

[0034] The utility model stores the overflowing electrolyte through the first groove 11 by arranging the first groove 11 on the upper surface of the top cover piece 1, thereby preventing the electrolyte from flowing into the explosion-proof valve, avoiding phenomena such as the explosion-proof valve being contaminated and corroded, and further prolonging the service life of the explosion-proof valve and improving the use safety of the cover plate mechanism.

Claims

1. A secondary battery top cover, characterized in that: include: A top cover sheet, wherein the top cover sheet is provided with two first planes and a second plane disposed back to back along the thickness direction thereof, the first plane is provided with a first groove, the bottom surface of the first groove is an inclined surface, the second plane is provided with a first protrusion, a second groove is provided in the first groove, a second protrusion is provided on the surface of the first protrusion, and a first injection hole penetrating the second protrusion is provided on the surface of the second groove; The lower plastic is assembled on the bottom surface of the top cover sheet, a third groove is formed on the upper surface of the lower plastic, a fourth groove is formed on the bottom surface of the third groove, and a second through-hole injection hole is formed in the fourth groove.

2. The secondary battery top cover according to claim 1, characterized in that: A waist-shaped hole is opened on the surface of the top cover sheet, and the depth of the bottom surface of the first groove close to the waist-shaped hole is smaller than the depth of the bottom surface of the first groove away from the waist-shaped hole.

3. The secondary battery top cover according to claim 1, characterized in that: A plurality of guiding grooves are evenly distributed on the side wall of the fourth groove.

4. The secondary battery top cover according to claim 1, characterized in that: The depth of the third groove is greater than the height of the first protrusion, and the inner diameter of the third groove is greater than the outer diameter of the first protrusion.

5. The secondary battery top cover according to claim 1, characterized in that: The depth of the fourth groove is greater than the height of the second protrusion, and the inner diameter of the fourth groove is greater than the outer diameter of the second protrusion.

6. The secondary battery top cover according to claim 2, characterized in that: An explosion-proof valve and a protective sheet are installed on the waist-shaped hole.

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