A novel battery thermal management system for cooling/preheating utilizing a polymer intercell heat exchanger with phase change material

The surge in electric vehicle adoption has spurred numerous investigations into battery thermal management systems, crucial for the stable operation of batteries. However, existing studies inadequately address the combined challenges of varied temperature conditions and the imperative to reduce weight for enhanced fuel efficiency. In response, this study proposes a liquid-based thermal management system, integrating a polymer-material heat exchanger with a phase change material, to enhance thermal performance and gravimetric energy density, simultaneously. The proposed structure excels in cooling performance, achieving target temperatures with a minimum decrease of 1.7 ℃ in maximum temperature and a temperature difference of at least 2.6 ℃ under fast charging conditions compared to alternatives. Furthermore, it exhibits unparalleled thermal homogeneity, reducing temperature differences by 4.8 ℃ with an optimal preheating duration under sub-zero conditions. Substituting metal with lightweight polymer material enhances gravimetric energy density alongside improved thermal performance. An upgraded polymer material reduces preheating time by 500 s, while an improved phase change material lowers maximum temperature and temperature difference by up to 3.0 ℃ and 1.0 ℃, respectively, during cooling. This research provides insights into comprehensive battery thermal management, addressing temperature regulation, weight reduction, and overall performance enhancement for electric vehicles.