Thermal management analysis using heat pipe in the high current discharging of lithium-ion battery in electric vehicles

Thermal management system (TMS) for commonly used lithium-ion (Li-ion) batteries is an essential requirement in electric vehicle operation due to the excessive heat generation of these batteries during fast charging/discharging. In the current study, a thermal model of lithium-titanate (LTO) cell and three cooling strategies comprising natural air cooling, forced fluid cooling, and a flat heat pipe-assisted method is proposed experimentally. A new thermal analysis of the single battery cell is conducted to identify the most critical zone of the cell in terms of heat generation. This analysis allowed us to maximize heat dissipation with only one heat pipe mounted on the vital region. For further evaluation of the proposed strategies, a computational fluid dynamic (CFD) model is built in COMSOL Multiphysics (R) and validated with surface temperature profile along the heat pipe and cell. For real applications, a numerical optimization computation is also conducted in the module level to investigate the cooling capacity of the liquid cooling system and liquid cooling system embedded heat pipe (LCHP). The results show that the single heat pipe provided up to 29.1% of the required cooling load in the 8C discharging rate. Moreover, in the module level, the liquid cooling system and LCHP show better performance compared with natural air cooling while reducing the module temperature by 29.9% and 32.6%, respectively.