Numerical Investigation on Optimisation of the Mass of PCM in a Hybrid Battery Thermal Management System

Abstract

A hybrid thermal management system for lithium-ion batteries, with convectional and Phase Change Material (PCM) based cooling is proposed. The thermal performance of the battery pack during the constant heat generation condition has been numerically analyzed based on a two-dimensional heat transfer model. The investigation is performed for the following cooling methods: natural convection, PCM plus natural convection, forced convection, and Hybrid cooling with air as the medium. It is found that the maximum temperature exceeds the optimal temperature range without a thermal management system. It is also found that thermal uniformity and maximum temperature can be maintained with only PCM (with thickness 3 to 5 mm) and hybrid cooling methods except in the case of 1 mm thickness. Furthermore, it is found that variable thickness of PCM can be used to optimize the weight and hence cost factors. Variable PCM thickness of 1mm for the first cell and 2 mm for the other 5 cells are found suitable, where both the thermal factors are not compromised at the optimized condition, up to 95.4% reduction in the mass is possible with variable PCM thickness