Investigation on battery thermal management based on phase change energy storage technology

Electric vehicles are gradually replacing some of the traditional fuel vehicles because of their characteristics in low pollution, energy-saving and environmental protection. In recent years, concerns over the explosion and combustion of batteries in electric vehicles are rising, and effective battery thermal management has become key point research. Phase change materials (PCM) can absorb or release a large amount of latent heat during the phase change process while maintaining a constant temperature (phase change temperature). In this paper, STAR-CCM+ software is used to carry out three-dimensional simulation of single cell and battery packs with PCM to investigate changing characteristics of battery temperature rise and temperature difference during the cooling and heat preservation process. At the same time, temperature rise and temperature difference of battery are analyzed under different ambient temperatures, convection heat transfer coefficients and phase change latent heats of PCMs. In summer, at an ambient temperature of 30 degrees C, when using PCM, the battery cell temperature can be reduced by 4 degrees C in 1800 s, which is about 8.6% lower than that without PCM. In winter, at an ambient temperature of -5 degrees C, the PCM with a melting point about 20 degrees C can keep the battery cell temperature drop of no more than 28% within 6700 s at a higher convection coefficient of 5 W/m(2)center dot K. Comparing the temperature of the battery pack with that of the battery cell, in the summer with an ambient temperature of 30 degrees C, the temperature of the battery pack decreased by 13.3 degrees C in 3600 s, while in the winter with an ambient temperature of -30 degrees C, the temperature of the battery pack increased by 14.3 degrees C in 5700 s. The use of phase change materials is conducive for batteries in electric vehicles to dissipate heat in summer and preserve heat in winter.