Experiments on liquid-immersed thermal runaway management for large energy-stored lithium-ion battery modules

• Conducts a test on thermal runaway of a large capacity battery module. • Effect of various fluids on battery’s thermal runaway behavior is studied. • Battery thermal runaway features in immersion and non-immersion are analyzed. • Immersion conditions lead to non-propagation of battery module thermal runaway. In addressing the thermal runaway management in large-capacity 280 Ah lithium-ion battery module for energy storage, a scheme of liquid-immersed thermal management is proposed to probe into the thermal runaway behavior of battery module in this study. The thermal runaway features under settings of immersion and natural convection air cooling, along with variations due to diverse coolant types and thermal runaway triggers. The findings indicate that natural convection air cooling conditions lead to thermal runaway propagation with peak temperatures soaring to 367.8 °C, contrary to immersion cases where no such propagation occurred. Particularly, overheating during overcharge scenarios yields higher peak temperatures (227.1 °C) than those seen in needle puncture tests (214.7 °C). Both hydrocarbon-based synthetic oil and modified silicone oil exhibited comparable capabilities in managing the thermal landscape and curbing thermal runaway, with the former excelling in heat dissipation and the latter in mitigating peak temperature spikes. The smoke duration of battery modules in non-immersed state is the longest (220 s), followed by overcharge thermal runaway in immersed state (130 s) and needle puncture thermal runaway (70 s). These results offer valuable guidance for thermal safety design and performance parameter optimization in battery storage systems.