Lithium ion battery and battery pack

Abstract

The invention discloses a lithium ion battery. The lithium ion battery comprises a battery casing, a battery top cap mounted on the battery casing and a pressure relief valve arranged on the battery casing and / or the battery top cap and further comprises a safeguard device, wherein the safeguard device is arranged on the battery casing and / or the battery top cap and fixed corresponding to the pressure relief valve; the safeguard device comprises a baffle plate corresponding to the pressure relief valve, a side wall and an air channel structure; the side wall extends towards the battery casing or the battery top cap from the baffle plate and is connected with the battery casing or the battery top cap; the air channel structure is formed on the side wall. Through the forming of the air channel structure on the side wall, the baffle plate and the air channel structure form relatively separating design, solid spark particles can be effectively blocked by the baffle plate, air can be efficiently discharged through the side air channel structure, and the safety performance of the lithium ion battery is improved.

Description

technical field [0001] The invention relates to the field of lithium ion batteries, in particular to a lithium ion battery and a battery pack. Background technique [0002] With the increasing application of lithium-ion batteries in fields such as electric vehicles and grid energy storage, more and more attention has been paid to the safety performance of lithium-ion batteries. Lithium-ion battery safety issues are often caused by thermal runaway. [0003] When thermal runaway occurs in the lithium-ion battery, the heat release of the active material in the lithium-ion battery can reach hundreds of joules per gram, and the instantaneous heat generation can cause a violent redox reaction between the active material and the electrolyte, resulting in a large amount of flammability. These gases make the internal pressure of the battery rise sharply, thus breaking through the explosion-proof valve to form a rapid gas flow, and the ejected flammable gas contacts and mixes with th...

AI Technical Summary

Problems solved by technology

However, the inventors of the present application have found that the mesh cover of Chinese Patent Application Publication No. CN103474599A still has some defects: when the battery is thermally runaway, the flammable gas inside the battery will be ejected quickly with high-temperature solid particles. The hole is only set on the top surface of the grille and is located in the direction of gas ejection. If the through hole on the top surface of the grille is too large, high-temperature solid particles will be ejected from the inside of the battery under the action of high-speed airflow, causing combustion , explosion; moreover, if the through hole is too large, the strength of the mesh cover will be reduced. Under the impact of the high-speed airflow mixed with high-temperature solid particles, the mesh cover will be easily damaged; Exhaust efficiency, and when the battery is out of control, the melted plastic parts, solid particles or metal slag ejected with the air flow will easily block the mesh, causing the internal pressure of the battery to rise sharply, causing a high risk of explosion

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