Influence of cycling aging and ambient pressure on the thermal safety features of lithium-ion battery

Abstract The fire and explosion risks of lithium-ion batteries (LIBs) pose serious threat to the transport and application of LIBs on the aircraft. Therefore, the study of corresponding thermal safety problems in flight condition is of great importance. In this work, a dynamic pressure chamber is used to study the effect of cycling aging and ambient pressure on the thermal safety features of LIBs. The results show that both the thermal runaway onset time and temperature decrease with the increase of cycle number or decrease of external pressure. The interval time between gas release and ignition decreases with the increase of cycle number, while the burning time increases with the decrease of pressure. Moreover, the thermal runaway temperature and heat release rate decrease with the increase of cycle number or decrease of pressure. The dV/dQ and X-ray computed tomography results show that the loss and structural damage of cathode materials, and the side reactions are the main factors for the decrease of battery safety. The easier occurrence of thermal runaway in low pressure is attributed to the larger differential pressure which facilitates the opening of burst disk and the entry of air.