Explosion-proof structure of square cover plate of lithium ion battery

Abstract

The utility model provides an explosion-proof structure of a square cover plate of a lithium ion battery, which belongs to the technical field of safety protection of energy storage batteries and comprises a base plate, a rectangular boss, a protective film and an explosion-proof valve, the boss is positioned in the middle of the base plate and is formed by punching, a hole formed by horizontally surrounding the inner side surface of the boss is an explosion-proof hole, and the explosion-proof valve is arranged in the boss. The anti-explosion valve is welded to the bottom face of the inner side of the boss, and the edge of the protective film is fixed to the upper surface of the boss. The anti-explosion valve is protected by using the stamping boss and the protective film with the penetrating nick, so that the anti-explosion valve has the effects of preventing the anti-explosion valve from being touched by mistake, preventing dust and ventilating, and has good practicability.

Description

Technical Field

[0001] The utility model belongs to the technical field of energy storage battery safety protection, in particular to an explosion-proof structure of a square cover plate of a lithium-ion battery. Background Art

[0002] Lithium-ion batteries have the advantages of high voltage, large specific energy, long cycle life and low self-discharge, and are widely used in many scenes of production and life. However, due to the high activity of lithium-ion batteries themselves, when the battery shell is squeezed and twisted, it is easy to generate gas and cause explosion. In this regard, invention patent CN102437293A discloses an explosion-proof battery cover for lithium batteries, wherein a pressure relief hole is provided on the cover body, an explosion-proof membrane is provided in the pressure relief hole, an explosion-proof cap is provided above the explosion-proof membrane, a sealing ring is provided between the explosion-proof membrane and the explosion-proof cap, and the explosion-proof cap is interference-fitted in the pressure relief hole. When the internal air pressure of the battery increases, the internal gas of the battery can break through the explosion-proof membrane on the cover body, discharge the high-pressure gas, and release the pressure in the battery. However, for a wider cover, after the battery produces gas, the internal pressure is too large, which can easily cause the cover to bend and deform, resulting in the explosion-proof membrane bursting before reaching the explosion value, affecting the safety performance of the battery. At the same time, invention patent CN109755437B discloses a battery explosion-proof structure and a battery explosion-proof cover plate using the battery explosion-proof structure. The explosion-proof hole and the injection hole are stacked up and down. The explosion-proof structure is a countersunk hole structure. The explosion-proof hole is arranged on the upper part of the countersunk hole. The center position of the explosion-proof piece protrudes toward the outer surface of the battery. The explosion-proof piece is connected and fixed to the explosion-proof hole by laser spot welding to achieve the effect of separating the explosion-proof piece from the explosion-proof hole to reduce pressure when the internal pressure of the battery exceeds the pressure threshold to avoid battery explosion. However, the cover plate still does not take structural strengthening measures. Utility Model Content

[0003] The technical problem to be solved by the utility model is to arrange a boss at the explosion-proof opening of the cover plate to realize the reinforcement of the cover plate structure and prevent the explosion-proof valve from bursting before the explosion value is reached. In view of the shortcomings of the prior art, a square cover plate explosion-proof structure for a lithium-ion battery is provided.

[0004] In order to solve the above technical problems, the technical solution adopted by the utility model is:

[0005] A lithium-ion battery square cover explosion-proof structure comprises a substrate, a boss, a protective film and an explosion-proof valve. The rectangular boss is located in the middle of the substrate and is formed by stamping. The hole formed in the horizontal direction around the inner side of the boss is an explosion-proof hole. The explosion-proof valve is welded to the inner bottom surface of the boss. The protective film covers the explosion-proof hole and its edge is fixedly connected to the upper surface of the boss.

[0006] Furthermore, the horizontal width of the boss is 5-20 mm greater than that of the explosion-proof hole, the length of the boss is 5-20 mm greater than that of the explosion-proof hole and is smaller than the width of the substrate, and the height of the boss is 1-3 mm.

[0007] Furthermore, the width of the substrate is ≥70 mm.

[0008] Furthermore, the protective film is provided with a penetrating notch, the width of the penetrating notch is 1-5 mm, and the horizontal distance from the inner side surface of the boss is 0.5-5 mm.

[0009] Furthermore, the penetrating notch on the protective film is in a straight line or an arc shape.

[0010] Compared with the prior art, the beneficial effects of the utility model are as follows:

[0011] Compared with the prior art, the utility model provides a lithium-ion battery square cover explosion-proof structure, which adopts a stamping integrally formed boss to strengthen the cover structure, has low manufacturing cost, and can effectively reduce the degree of bending deformation of the cover when abnormal gas is produced inside the battery to prevent the explosion-proof valve from bursting when the explosion-proof value is not reached, and also provides a stable installation working environment for the explosion-proof valve and the protective film. The protective film can prevent accidental touch and foreign matter from affecting the explosion-proof valve, and the penetrating notch set thereon can release the air pressure between the protective film and the explosion-proof valve when the battery is heated or cooled, so that the outside of the explosion-proof valve is in a normal pressure state, which has good safety and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0013] Figure 2 for Figure 1 A partial enlarged view of the middle position X;

[0014] Figure 3 A top view of the substrate of Example 1 of the utility model;

[0015] Figure 4 This is a schematic diagram of the structure of the protective film of Example 1 of the utility model;

[0016] Among them, 1-substrate, 2-boss, 3-protective film, 4-explosion-proof valve. DETAILED DESCRIPTION

[0017] In order to better understand the present invention, the content of the present invention is further clearly described below in conjunction with the embodiments, but the protection content of the present invention is not limited to the following embodiments. In the following description, a large number of specific details are given in order to provide a more thorough understanding of the present invention. However, it is obvious to those skilled in the art that the present invention can be implemented without one or more of these details.

[0018] In the description of the present invention, it is necessary to understand that the terms "upper", "lower", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0019] In the present invention, unless otherwise clearly specified and limited, the terms such as "connection" shall be understood in a broad sense, for example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a direct connection, or an indirect connection through an intermediate medium, or it may be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0020] Example 1

[0021] See also Figure 1-Figure 4 , including a substrate 1, a boss 2, a protective film 3 and an explosion-proof valve 4. The width of the substrate 1 is ≥70mm. The boss 2 is rectangular and is located in the middle of the substrate 1 by stamping. The height is 1-3mm. The hole formed by the inner side of the boss 2 along the horizontal direction is an explosion-proof hole. The horizontal width of the boss 2 is 5-20mm more than the explosion-proof hole, and the length of the boss 2 is 5-20mm more than the length of the explosion-proof hole. The explosion-proof valve 4 is welded to the inner bottom surface of the boss 2. The protective film 3 covers the explosion-proof hole and the edge is fixedly connected to the upper surface of the boss 2. The protective film 3 is provided with a penetrating notch. The shape of the notch is linear or arc-shaped. The width of the penetrating notch is 1-5mm, and the horizontal distance from the inner side of the boss 2 is 0.5-5mm.

[0022] The technical solution provided in the embodiment of the present application constructs a rectangular boss through stamping and forming. The integrated structure ensures stability and manufacturing efficiency. The explosion-proof hole obtained thereby facilitates the installation of the protective film. The protective film can prevent external foreign matter from interfering with the explosion-proof valve. The penetrating notches on the film are used to balance the air pressure inside and outside the film, so that the air between the explosion-proof film and the protective film is at normal pressure, which will not have a negative impact on the operation of the explosion-proof film.

[0023] Finally, it should be noted that the above embodiments are only preferred embodiments of the present invention, which are only used to illustrate the technical solution of the present invention rather than to limit it. Any modification, improvement, other modification or equivalent replacement made to the technical solution of the present invention by ordinary technicians in this field, as long as they do not depart from the spirit and scope of the technical solution of the present invention, should be included in the protection scope of the present invention.

Claims

1. A lithium-ion battery square cover explosion-proof structure, characterized in that: The invention comprises a base plate (1), a boss (2), a protective film (3) and an explosion-proof valve (4); the boss (2) is rectangular and is located in the middle of the base plate (1) and is formed by stamping; a hole formed in the horizontal direction around the inner side surface of the boss (2) is an explosion-proof hole; the explosion-proof valve (4) is welded to the inner bottom surface of the boss (2); the protective film (3) covers the explosion-proof hole and its edge is fixedly connected to the upper surface of the boss (2).

2. The lithium-ion battery square cover explosion-proof structure according to claim 1, characterized in that: The horizontal width of the boss (2) is 5-20 mm greater than that of the explosion-proof hole, the length of the boss (2) is 5-20 mm greater than that of the explosion-proof hole, and the height of the boss (2) is 1-3 mm.

3. The lithium-ion battery square cover explosion-proof structure according to claim 1, characterized in that: The width of the substrate (1) is ≥70 mm.

4. The lithium-ion battery square cover explosion-proof structure according to claim 1, characterized in that: The protective film (3) is provided with a penetrating notch, the width of the penetrating notch is 1-5 mm, and the horizontal distance from the inner side surface of the boss (2) is 0.5-5 mm.

5. The lithium-ion battery square cover explosion-proof structure as claimed in claim 4, characterized in that: The shape of the penetrating notch on the protective film (3) is a straight line or an arc.

Images