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 degrees C. The results show that the proposed BTMS inhibits TR and its propagation effectively, the temperature of overcharge-cell surface remains below 185 degrees C, and it remains above 60 degrees 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 degrees C. The corresponding temperature difference of all observation points is below 2.1 degrees 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.