Power type lithium ion battery cover and welding process thereof

Abstract

The invention relates to a power type lithium ion battery cover and a welding process thereof. An upper cover, a gasket and an anti-explosion film are embedded into a sealing ring; a pore plate and the anti-explosion film are subjected to laser spot welding; more than two downward convex welding points are uniformly arranged on the lower surface of the edge of the upper cover, and the convex height of the welding points is greater than the thickness of the gasket; the upper cover is sequentially in resistance welding with the gasket and the bottom surfaces in a cavity of the anti-explosion film through the more than two convex welding points; the bottom face of the anti-explosion film is provided with an annular pressure-relief notching groove; the wall of an inner hole of the gasket corresponds to the annular pressure-relief notching groove. The upper cover is sequentially in resistance welding with the gasket and the bottom surfaces in the cavity of the anti-explosion film along the downward convex welding points, is matched with the inner hole of the gasket and corresponds to the anti-explosion film with the annular pressure-relief notching groove in the bottom face, so as to reduce the inner resistance of the whole battery cover and stabilize anti-explosion pressure relief. The power type lithium ion battery cover is simple in connection structure, stable in connection, low in deformation and malposition possibility and low in whole inner resistance; by adoption of the power type lithium ion battery cover, the battery has high performance, stable anti-explosion performance, high safety performance and long service life.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a lithium ion power battery cap and its welding process. Background technique [0002] The lithium-ion battery cap is a key component of the lithium-ion battery, which is directly related to the reliability, service life, capacity, production and use safety of the producer and consumer of the lithium-ion battery. The internal resistance of the lithium-ion power battery cap directly affects the service life and overcharge and over-discharge performance of the lithium-ion battery. The larger the internal resistance of the lithium-ion battery, the greater its self-discharge, which affects the capacity of the entire battery. The existing methods for reducing the internal resistance of lithium-ion battery caps are laser welding and ultrasonic welding. The disadvantages are: high processing costs, easy damage to the coating on the upper cap and rust, small fusion area of ​​sold...

AI Technical Summary

Problems solved by technology

The internal resistance of the lithium-ion power battery cap directly affects the service life and overcharge and over-discharge performance of the lithium-ion battery. The larger the internal resistance of the lithium-ion battery, the greater the self-discharge, which affects the capacity of the entire battery

The existing methods for reducing the internal resistance of lithium-ion battery caps are laser welding and ultrasonic welding. The disadvantages are: high processing costs, easy damage to the coating on the upper cap and rust, small fusion area of ​​solder joints or weak welding. It is easy to break when the force is applied, so that the internal resistance of the cap becomes larger

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