Analytical Study on Thermal Runaway Propagation and Inter-electrode Dynamics in Lithium-Ion Battery Applications: Insights into Battery Safety

It is essential to ensure thermal safety in lithium-ion (Li-ion) batteries to facilitate their increased use in electric cars, thereby enhancing the safety of individual batteries. When high-power Li-ion batteries are subjected to abusive conditions, they frequently experience thermal runaway (TR) due to a sequence of exothermic reactions resulting from electrode contacts. These events generate a significant amount of heat and have the potential to cause thermal runaway propagation (TRP) throughout the battery module. This paper presents an in-depth TRP analysis approach, combining thermo-kinetic and electrode interaction assessments at the cell level. The method is implemented on the TR properties of a cylindrical Li-ion cell equipped with nickel-rich and silicon-carbon electrodes. The developed TRP approach, incorporating various heat dissipation techniques, is applied to a prototype high-energy Li-ion chamber to evaluate TRP susceptibility under different conditions, including ambient temperature, cell spacing, initiating cell location, external heating power, and heat dissipation rates. Additionally, this research provides insights into the various TRP pathways, focusing on aspects such as the propagation rate, the exothermic processes' thermal, required thermal energy input, and external heat release. The comprehensive model, considering both heat transfer and chemical interactions between electrodes under TR, can address accurate TR- propagation examinations for batteries. Moreover, it can be expanded to larger battery systems, ultimately improving overall battery safety.