EG@Bi-MOF derived porous carbon/lauric acid composite phase change materials for thermal management of batteries

Driven by the development of electric vehicles, there is an unmet need to protect power battery from sharp temperature rise and thermal runaway. This study aims to design a new type of composite phase change material for thermal management of battery. By adsorption of lauric acid (LA), LA/EG@HPC composite phase change material with stable shape can be obtained. The BET surface area of the carrier is 15.9326 m2/g, and the pore size distribution is mainly mesoporous and macroporous. The three-dimensional structure of the carrier can provide a continuous layered heat transfer network channel for LA. The load rate of the composite phase change material can be up to 70%, and the thermal conductivity is 2.546 W/(m·K), 8.4 times that of pure LA. In addition, currently MOF materials used in phase change material carrier are synthesized by reaction kettle. The solvothermal method adopted in this study can greatly improve the single synthesis yield and is easy to operate. The composite phase change material shows excellent performance in the thermal management of batteries. In the discharge test of different rates, the maximum temperature of the battery pack is reduced by 13.4 °C compared with that of the battery pack without thermal management, the temperature difference of the battery is reduced by 1–1.5 °C, and the operating temperature is far lower than the safe temperature of 50 °C. During the cycle test, the temperature fluctuation of composite phase change material group is reduced by 45% under DST condition, and the temperature of the battery under constant high rate condition is maintained below the safe temperature, which has a remarkable thermal management effect.