Investigation into Thermal Cooling with Different Ferrofluid Flow Arrangements for a Lithium-Ion Battery Pack

Abstract

Energy storage performance and its long life are strongly related to its operating conditions. Due to greater power density, more compactness, and longer service life, thermal chilling methods are essential to keep the designed temperature range. The 18650 lithium-ion cylindrical battery module (60 cells) with ferrofluid (0.015% by volume) as coolant with two different flow arrangements was investigated with charging and discharging processes. The turbulent model was used to solve the model of determining the maximum temperature and the temperature distribution, which significantly affects the long lifecycle and thermal performance. Model I gives a maximum temperature of 30 °C, and model II has a maximum temperature of 32 °C. In addition, model I gives a lower battery pack temperature difference than model II. Regarding cell temperature, the top zone of the cells has a higher temperature than the bottom zone and gives a maximum difference of about 0.25–0.5 °C for model I and 0.50-1.00 °C for model II. The predicted temperature distributions are compared with those from the experimental data, and good agreement is reached. The improved flow direction of coolant significantly affects the decreasing maximum operating temperature and the cell temperature difference.