Comprehensive hazard analysis of failing automotive lithium‐ion batteries in overtemperature experiments

Lithium-ion batteries (LIBs) are gaining importance in the automotive sector because of thepotential of electric vehicles (EVs) to reduce greenhouse gas emissions and air pollution. However,there are serious hazards resulting from failing battery cells leading to exothermic chemical reactionsinside the cell, called thermal runaway (TR). Literature of quantifying the failing behavior of modernautomotive high capacity cells is rare and focusing on single hazard categories such as heat generation.Thus, the aim of this study is to quantify several hazard relevant parameters of a failing currentlyused battery cell extracted from a modern mass-produced EV: the temperature response of the cell,the maximum reached cell surface temperature, the amount of produced vent gas, the gas ventingrate, the composition of the produced gases including electrolyte vapor and the size and compositionof the produced particles at TR. For this purpose, overtemperature experiments with fresh 41 Ahautomotive lithium NMC/LMO—graphite pouch cells at dierent state-of-charge (SOC) 100%, 30%and 0% are performed. The results are valuable for firefighters, battery pack designers, cell recyclers,cell transportation and all who deal with batteries.