Experimental study on aerogel passive thermal control method for cylindrical lithium-ion batteries at low temperature

The power and energy densities of battery will decrease at low temperature and the heat preservation is necessary to keep the battery warm. In this paper, a passive thermal control method with nano-porous aerogel heat-insulation is proposed. The effects of various ambient temperatures, different discharge currents and different aerogel thicknesses on the battery electric and thermal behavior are experimentally studied. The results reveal that aerogel has a significant effect on warming the battery up. Taking advantage of porous structure, low thermal conductivity and low thermal diffusivity, the heat generated during operation process of battery will be greatly retained and slowly released to the ambient environment. The improved thermal conditions lead to higher voltage platform and discharge capacity. Compared with the battery directly exposed to low temperature, the voltage increases by 24.95% under 3.0A current at -15 degrees C with thermal control method. In addition, the practical electrochemical energy utilization efficiency is higher than 90% for most discharging period of time. Furthermore, the performance of aerogel is found to be related to its thickness. These investigations are expected to provide effective knowledge on battery passive thermal management at low temperature.