A new concept of thermal management system in Li-ion battery using air cooling and heat pipe for electric vehicles

This paper presents the concept of a hybrid thermal management system (TMS), including air cooling and heat pipe for electric vehicles (EVs). Mathematical and thermal models are described to predict the thermal behavior of a battery module consisting of 24 cylindrical cells. Details of various thermal management techniques, especially natural air cooling and forced-air cooling TMS are discussed and compared. Moreover, several optimizations comprising the effect of cell spacing, air velocity, different ambient temperatures, and adding a heat pipe with copper sheets (HPCS) are proposed. The mathematical models are solved by COMSOL Multiphysics (R), the commercial computational fluid dynamics (CFD) software. The simulation results are validated against experimental data indicating that the proposed cooling method is robust to optimize the TMS with HPCS, which provides guidelines for further design optimization for similar systems. Results indicate that the maximum module temperature for the cooling strategy using forced-air cooling, heat pipe, and HPCS reaches 42.4 degrees C, 37.5 degrees C, and 37.1 degrees C which can reduce the module temperature compared with natural air cooling by up to 34.5%, 42.1%, and 42.7% respectively. Furthermore, there is 39.2%, 66.5%, and 73.4% improvement in the temperature uniformity of the battery module for forced-air cooling, heat pipe, and HPCS respectively.