Safe cap component for lithium ionic cell

Abstract

The invention provides a safety cap component of a lithium ion battery, which comprises a rupture disc with a downward boss, a lower resistance thermistor component, a steel cap, a partition plate and an insulating washer, wherein the downward boss of the rupture disc is equipped with a flat peak, the lower resistance thermistor component is arranged on the upper surface of the rupture disc, the steel cap is arranged on the lower resistance thermistor component, the partition plate is arranged on the lower side of the rupture disc to connect to the tip of the downward convex and contains a vent hole, the insulting washer is coated outside the steel cap, the rupture disc, the lower resistance thermistor component and the partition plate, and the lower resistance thermistor component comprises a ring-shaped plastic piece with a hole and a lower resistance thermistor sheet embedded in the hole. The safety cap component of a lithium ion battery can be mounted integrally, and displacement among components can be prevented, and the cap component has low integral resistance with reliable actuation performance.

Description

technical field [0001] The invention relates to a safety cap for a lithium ion battery. Background technique [0002] A lithium-ion battery is a commonly used battery. The current lithium-ion battery generally adopts a sealed structure. When the battery is overcharged or short-circuited, the temperature inside the battery is too high, and the electrolyte in the battery will quickly evaporate into a large amount of gas, which will cause a sharp increase in the internal pressure of the battery. [0003] In order to prevent the explosion caused by the sudden increase of the internal pressure of the lithium-ion battery, a safety valve is usually set in the lithium-ion battery. One type of safety valve that has been adopted in lithium-ion batteries uses a shut-off member that cuts off the circuit when the internal pressure rises above a certain level. Such as the technology reported in the patent of 02258513.3, this technology adopts a ring-shaped thermistor plate, and the ring...

AI Technical Summary

Problems solved by technology

Such as the technology reported in the patent of 02258513.3, this technology adopts a ring-shaped thermistor plate, and the ring-shaped thermistor plate is made of a polymer positive temperature coefficient thermistor material to form an integral device. One of the biggest defects that exists is: ring The resistance of the thermistor plate is relatively large, generally 10-30 milliohms, which increases the overall resistance of the cap assembly; and when the lithium-ion battery is overcharged or short-circuited for a long time, the local pressure on the ring-shaped thermistor plate is very high. Large, which hinders the resistance of the ring-shaped thermistor plate to increase when the temperature rises, resulting in poor current blocking effect

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