Risk analysis method for thermal runaway gas toxicity of lithium-ion batteries

A method to analyse the toxicity of thermal runaway gases of batteries, referring to the risk assessment theory was proposed. It aims to investigate the hazard ratings of the main harmful substances in the thermal runaway gas of lithium-ion batteries.By using the fractional effective dose (FED) equation and a gas sensor array, the results of the method used to characterize the likelihood of thermal runaway of lithium batteries occurred were discovered.The thermal runaway gas toxicity kinetic model of the battery was demonstrated in order to identify the consequences of gas toxicity, while the toxicity risk of thermal runaway gas in ternary lithium-ion batteries under different states of charge (SOC) was analyzed accordingly. The results retrieved show that high SOC batteries are more likely to enter the thermal runaway state, and the total amount of CO, HF and gas released by thermal runaway increases according to the SOC of batteries. As a result, the risk of thermal runaway increases with battery SOC.A fully (100%) charged battery has about 8 times the toxicity risk of a 25% charged battery and requires 11 times the fresh air dilution to reach a safe concentration.The results provided data reference for the early warning of lithium battery thermal runaway and the toxicity evaluation of pyrolysis gas. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.