Structural optimization of light-weight battery module based on hybrid liquid cooling with high latent heat PCM

Abstract

In this work, the advantages of a novel hybrid cooling for a battery module are demonstrated over the single liquid cooling and the encapsulant cases, and then a structural optimization for the hybrid cooling system is conducted based on the response surface methodology (RSM) and numerical modeling. The cooling structure consists of a minichannel cold plate at the bottom, which is also connected to the lateral sides of the batteries in parallel through the thermal columns and heat spreading plate, with high latent heat PCM filled among batteries. Comparing with the single liquid cooling case without PCM, the maximum temperature and temperature difference of the present hybrid cooling system (baseline case) are reduced by about 42.67% and 38.27%, respectively. Single factor analysis is first conducted to identify the significance of different structural parameters based on the sensitivity analysis. Then, the multi-objective optimization is conducted to achieve a balanced design with reduced maximum temperature, temperature difference and thermal system mass by using the central composite design (CCD) combined with RSM. Moreover, a local optimization can further reduce the temperature difference of the battery module. The optimization results show that the final optimized solution (Design 5) can control the temperature difference and thermal system mass of the battery module at the lowest level of 3.7 °C and 107.1 g by maintaining the maximum temperature below 48.5 °C at the high discharge rate of 4C.