Apparatus for preventing power lithium ion battery pack from thermal runaway

Abstract

The invention discloses an apparatus for preventing a power lithium ion battery pack from thermal runaway. The apparatus is used for a battery pack with a battery management system, wherein the battery pack comprises a plurality of battery units, the positive electrode ends and the negative electrode ends of each battery unit are respectively connected to a branch circuit in parallel, the branch circuit comprises an external resistor and a circuit switch control component, each circuit switch control component is connected to the battery management system through signal, the battery managementsystem is used for monitoring and determining whether each battery unit has an internal short circuit, and if the battery management system monitors and determines that the internal short circuit occurs in a certain battery unit, the circuit switch control element is conducted, such that the battery unit with the internal short circuit is short-circuited externally. According to the present invention, with the apparatus, on the basis of the traditional battery pack with the battery management system (BMS), the circuit switch control component and the small external resistance forming component are additionally arranged in each series connection branch circuit, such that the temperature monitoring and the voltage monitoring are performed by the battery management system, and the apparatushas advantages of easy operation and low cost.

Description

technical field [0001] The invention relates to the technical field of electric vehicle power lithium-ion batteries, in particular to a device for preventing thermal runaway of power lithium-ion battery packs. Background technique [0002] Power lithium-ion batteries have been widely used in electric vehicles due to their high energy density, long life, and environmental protection. However, fire and explosion accidents of power lithium-ion batteries are often heard. The safety of power lithium-ion batteries seriously threatens the lives of users and restricts the further development of the electric vehicle industry. It is an urgent problem to be solved. [0003] The fire and explosion of the power lithium-ion battery is the result of the development of thermal runaway. There are several main factors inducing the thermal runaway of power lithium-ion batteries, (1) mechanical induction, such as acupuncture, squeezing the battery, causing diaphragm damage and internal short c...

AI Technical Summary

Problems solved by technology

[0004] From the internal short circuit to the final thermal runaway, the main reason is that a large amount of current passes through the internal resistance of the internal short circuit, which instantly generates a large amount of heat, resulting in a sharp rise in temperature, and triggers further melting of the separator and exothermic reaction of the internal materials of the battery. cause thermal runaway

After the thermal runaway of a single battery cell, due to heat transfer and other reasons, it will cause thermal runaway of adjacent battery cells, form thermal runaway propagation in the battery pack, and lead to catastrophic accidents

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