Experimental investigation of battery thermal management and safety with heat pipe and immersion phase change liquid

This paper presents a battery thermal management system (BTMS) with heat pipe and phase-change-liquid to control temperature and inhibit thermal runaway (TR). The proposed BTMS utilizes the cooling capacity and flame retardancy of fluid immersion and the high heat-transfer efficiency of heat pipes. An aged cell is overcharged at 60 A under an ambient temperature of 10 °C. The results show that the proposed BTMS inhibits TR and its propagation effectively, the temperature of overcharge-cell surface remains below 185 °C, and it remains above 60 °C for only 14 s. The experimental results of normal operation indicate that the BTMS operates with heat-pipe & liquid-phase-change mode under high discharge rates and high-power cycle, and the maximum temperature of batteries is limited to 47 ± 1 °C. The corresponding temperature difference of all observation points is below 2.1 °C. The effectiveness of an increase in air velocity is limited in boiling state owing to heat dissipation and vapours pressure, however, it significantly mitigates the temperature rise in non-boiling state; meanwhile, it demonstrates a slight non-monotonic effect on temperature consistency. These results provide an insight into the optimization of BTMS to manage batteries with high power and long safe-operating-life requirements.