Experimental study on heating performance of pure electric vehicle power battery under low temperature environment

For effective solutions to performance problems, such as discharge capacity attenuation of the pure electric vehicle (EVs) power battery under low temperatures, the heating module of the pulsating heat pipe (TiO2-CLPHP) for the power battery was constructed with TiO2 nanofluid as working medium. Moreover, heating performance experiments under different heating strategies were carried out through consideration of the higher efficient bidirectional thermal transfer and thermal conductivity characteristics of the pulsating heat pipe, along with thermal management technology. The results demonstrated that the optimal heat transfer performance of TiO2-CLPHP could be achieved with working medium concentration of 2% and heat pipe filling ratio of 50%. In addition, TiO2-CLPHP was utilized for the preheating and heat preservation of power batteries, which could highly reduce the fluctuation of voltage during discharge, as well as improve the low-temperature discharge capacity of power batteries, followed by the effective surface temperature uniformity improvement of the battery (maximum temperature difference on power battery surface did not exceed 2.6 degrees C). Furthermore, when TiO2-CLPHP was utilized for the power battery heating under continuous heat preservation, the discharge capacity of the power battery reached 58.69Ah, while the capacity enhancement ratio reached up to 56.6%. Therefore, on the basis of the current research, through comprehensive consideration of preheating, heat preservation (preheating time, discharge voltage and discharge capacity) and energy consumption, it proved that the preheating coupled continuous heat preservation was an ideal heating strategy. Through this strategy, rapid heating along with discharge voltage and discharge capacity increase to the maximum extent, the performance of the EVs power battery under low-temperatures was improved. (C) 2021 Elsevier Ltd. All rights reserved.