Experimental Study of a Direct Immersion Liquid Cooling of a Li-Ion Battery for Electric Vehicles Applications

The aim of this work is to test a battery thermal management system by direct immersion of a commercial 18650 LiFePO4 cell in a low boiling dielectric liquid.It is worth noting that for electric mobility applications, thermal management of Lithium-Ion batteries is a fundamental issue because batteries experience high discharge currents and temperatures.First, we present an electrical characterization of the Lithium-Ion by measuring cell potential, open circuit potential and entropic heat coefficient.Temperature measurements were carried out with thermocouples and infrared thermography.A simplified heat generation term was evaluated using the experimental data.Then, the same battery was immersed in a dielectric low boiling liquid and tested under three different discharge currents.For comparison, also the case without dielectric liquid was analyzed.This paper demonstrates the feasibility of a thermal management system based on direct immersion of a battery cell in a low boiling dielectric fluid.Indeed, the results show a substantial decrease of battery temperature when immersed.