A Comprehensive Model and Experimental Investigation of Venting Dynamics and Mass Loss in Lithium-ion Batteries under Thermal Runaway

Thermal runaway (TR) has become a critical safety concern with the widespread use of lithium-ion batteries (LIBs) as an energy storage solution to meet the growing global energy demand. This issue has become a significant barrier to the expansion of LIB technologies. Addressing the urgent need for safer LIBs, this study developed a comprehensive model to simulate TR in cylindrical 18650 Nickel Cobalt Manganese (NMC) LIBs. By incorporating experiments with LG®-INR18650-MJ1 cells, the model specifically aims to accurately predict critical TR parameters, including temperature evolution, internal pressure changes, venting phases, and mass loss dynamics. The simulation closely correlated with experimental outcomes, particularly in replicating double venting mechanisms, gas generation and the characteristics of mass loss observed during TR events. The study confirmed the feasibility of assuming proportional relationships between gas generation and cell capacity, and between mass loss from solid particle ejection and total mass loss, thereby simplifying the modeling of both gas generation and mass loss behaviors in LIBs under TR. Conclusively, the findings advanced understanding of TR mechanisms in LIBs, providing a solid foundation for future research aimed at mitigating risks and promoting the safe integration of LIBs into sustainable energy solutions.