Modeling of thermal runaway propagation of NMC battery packs after fast charging operation

Abstract

This study presents a mathematical model and experimental verification of factors influencing thermal runaway propagation of NCM811/C lithium-ion battery module after fast charging operation. The key factors considered for the thermal runaway propagation include charging C-rate, battery spacing, triggering temperature, speed, and interval of the thermal runaway propagation. The analysis of the 3D model shows that increasing the spacing and triggering temperature of the battery will reduce the risk of thermal runaway propagation of the battery module and change the order of thermal runaway propagation. Further, the thermal runaway propagation speed increases gradually with the propagation process; however, it is inhibited by increasing triggering temperature and battery spacing and the decrease of charging C-rate. These observations play a critical role in the lithium-ion battery pack design.