Experimental and simulative investigations on a phase change material nano-emulsion-based liquid cooling thermal management system for a lithium-ion battery pack

Thermal management systems (TMSs) are indispensable for practical applications of lithium-ion battery packs. In this study, phase change material (PCM) nano-emulsions with enhanced energy storage capacity, excellent dispersion stability, low viscosity and good thermal reliability were employed as coolants for high-performance liquid cooling thermal management systems (LCTMSs) for the first time. The maximum temperature (T-max) and maximum temperature difference (Delta T-max) in a 5S4P battery pack were measured to evaluate the thermal management performance of these coolants. When a 10 wt% OP28E nano-emulsion was used at a flow rate of 200 mL min(-1), T-max and Delta T-max were 1.1 degrees C and 0.8 degrees C, respectively, lower than those based on water, at a discharge rate of 2C. The increase in OP28E mass fraction of the nano-emulsion led to a gradual decrease in T-max and Delta T-max at identical discharge rates. Simulation studies were also conducted and validated by comparing with the experimental results. It was revealed that, T-max and Delta T-max decreased with increasing flow rate of the coolants, and the thermal management performance of the 10 wt% OP28E nano-emulsion was always better than that of water. This work sheds light on improving the performance of LCTMSs by using PCM nano-emulsions. (C) 2020 Elsevier Ltd. All rights reserved.