Thermal Analysis of a Li-Ion Battery Coupled with Phase Change Material (Paraffin Wax RT-35) filled with Copper Metal Foam: A Numerical Study

Abstract

In the current battery technologies, Lithium-ion (Li-ion) batteries have depicted their immense potential to power current electric vehicles (EVs) and hybrid electric vehicles (HEVs). Few distinguished qualities of these batteries are lightweight, high specific energy, lesser self-discharge, long lifecycle, and negligible memory effect. However, these batteries generate a significant amount of heat during their operations, which affects their performance and increases the risk of phenomena like capacity degradation, thermal runaway, and fire. The present study investigates a passive battery thermal management system embedded with phase change material (PCM, paraffin wax RT-35) and porous media (Copper foam). A prismatic Li-ion cell (Li[Ni-CoMn]O2 cathode and graphite anode) having a capacity of 20Ah with a nominal voltage of 3.65 V is investigated. The lower thermal conductivity of the PCM is countered by utilizing a copper foam of 0.95 porosity having 20 pores per inch (PPI). The present study adopts both thermal equilibrium and thermal non-equilibrium models to study the heat transfer analysis in PCM embedded with porous media. It is found that with the application of PCM/PCM-MF in the Li-ion cell, the temperature increase can be effectively controlled. The average temperature rise of the entire cell domain for 5C discharge is decreased by 79.04% & 80.76% by using PCM and PCM-MF, respectively, compared to naturally air-cooled cell. In the case of 4C discharge, the decrement is 78.30% and 79.31%, respectively, for PCM and PCM-MF. The maximum differential temperature is lower using PCM-MF for both the discharge rates. Copyright © 2022 by ASME.