Method and system for evaluating abnormal state of lithium ion battery based on VOC gas

Abstract

The invention discloses a VOC gas-based lithium ion battery abnormal state evaluation method and system. The method comprises the following steps of firstly, setting a first threshold value, a second threshold value and a third threshold value of VOC gas concentration, a VOC concentration change rate threshold value, a time interval and a sampling frequency, and calculating a total concentration value and a change rate of the VOC gas in a subsequent time interval when the concentration value of continuous multi-point VOC gas emitted by a lithium ion battery is monitored to exceed the first threshold value in real time; the abnormal degree of the state of the lithium ion battery being judged by further combining the relation between the total VOC gas concentration value and the second threshold value and the third threshold value and the relation between the VOC gas change rate and the change rate threshold value. The method is simple in principle, easy to implement, wide in application scene and capable of accurately and reliably evaluating an abnormal state of the lithium ion battery.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery safety, and in particular relates to a method and system for evaluating the abnormal state of lithium-ion batteries based on VOC gas. Background technique [0002] With the continuous improvement of lithium-ion battery manufacturing process and packaging level, lithium-ion batteries have achieved more and more applications. Ion batteries themselves have potential safety hazards that cannot be ignored. With the improvement of energy density and other indicators of lithium-ion batteries, the safety issues of lithium-ion batteries have become more and more acute. Considering that when the battery is abnormal, it is accompanied by changes in various parameters such as voltage, internal resistance, and temperature, and is accompanied by the generation of characteristic gases. Taking such parameters as fault identification parameters and introducing the battery abnormal state evaluation mech...

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Problems solved by technology

Zheng Jiemin, Lei Zhanxiu, Zhang Shiyang and others authorized the invention patent in 2020 "A Control System and Control Method for Liquid Leakage of Electric Vehicle Power Battery Box" (Patent No. CN107959066B) mentioning the use of gas signal change rate for lithium-ion battery fault diagnosis , but the invention does not propose what kind of gas signal to use, and the tedious signal conversion process makes the invention extremely complicated

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