Top cover of secondary battery and secondary battery

Abstract

The invention discloses a top cover of a secondary battery. The top cover of the secondary battery comprises an anti-explosion valve and an external short circuit connecting device, wherein the anti-explosion valve comprises an explosion-proof sheet and a first insulation sheet; the first insulation sheet comprises a main body part and a protruding part; the external short circuit connecting device comprises a conductive connecting sheet, a second insulation sheet, an elastic deformation part and a conductive boss; the second insulation sheet separates the conductive connecting sheet from theconductive boss for insulating; the elastic deformation part comprises a fixed part and a movable part; the fixed part is arranged on the connecting sheet; the movable part is arranged corresponding to the conductive boss, and the protruding part separates the movable part from the conductive boss for insulating; elastic deformation is formed towards the direction far away from the conductive boss. The top cover, provided by the invention, of the secondary battery not only can timely and effectively leak the internal pressure of the battery, but also can trigger an external short circuit of the battery in time, thus preventing the battery from being out of thermal control in a high temperature environment and improving the security of the overall battery.

Description

technical field [0001] The invention belongs to the technical field of batteries, and in particular relates to a secondary battery top cover and a secondary battery. Background technique [0002] Due to the advantages of high energy density and long cycle life, lithium-ion batteries are widely used in consumer electronics, new energy vehicles, and energy storage. With the continuous improvement of energy density requirements in practical applications, more materials with high energy density but poor thermal stability have entered commercial battery systems, and the safety performance of lithium-ion batteries is facing huge challenges. [0003] Generally speaking, when the battery is used improperly, such as overcharging, short circuit or being exposed to high temperature environment, the battery will easily generate a large amount of gas and heat due to internal reactions, and even internal short circuit will cause thermal runaway. In order to reduce the harm caused by the ...

AI Technical Summary

Problems solved by technology

Due to the large amount of gas produced by the decomposition of the electrolyte in a high temperature environment, it is easy to cause a large amount of gas to be generated without the risk of internal short circuit, resulting in the internal pressure reaching the set external short circuit trigger value

However, after the external short circuit is triggered, the electrical connection of the positive and negative electrodes will cause the internal temperature to rise faster, increasing the risk

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