Selection of an Ideal Coolant to Ward Off the Thermal Runaway of a Pouch Type Li-Ion Battery Module

Abstract

To uphold the temperature within an acceptable range of Li-ion batteries in electric vehicles, appropriate thermo-regulation strategies should be implemented. If the temperature is increased beyond the permissible range during the charging/discharging cycle, there is a possibility of overheating and electrolyte fire, which leads to degradation of the lifecycle and capability of the cell. This research suggests the usage of nanofluids as a heat transfer medium for active thermal management. A numerical approach is employed to analyze the effectiveness of nanofluids and their impact on the temperature gradient within the battery module. The thermal performance of water and water:ethylene glycol-based nanofluid is numerically examined where the water shows better performance due to excellent thermal properties, whereas the dispersion of nanoparticles in base fluids shows a notable effect on reducing the temperature of the battery module, while a limited effect on temperature uniformity. Besides, an enhancement in performance is seen with the growth in the volume fraction of nanoparticles amid an increased pumping power at the same time. The impact of different functioning parameters such as inlet velocity, coolant temperature, and discharge rate is also analyzed for water-based nanofluids. Results indicate that with an increase in coolant velocity, alumina nanofluid can provide better uniformity and reduce the battery module temperature than the base fluid.