Abstract
An effective battery thermal management system (BTMS) is of great significance to ensure the safety and efficiency of lithium-ion batteries (LIBs). Both the temperature properties and lightweight are essential to the BTMS in electric vehicles. To fulfill these targets, a direct contact liquid-cooling system with multichannel is designed for the LIB module, and the simulation model is established and validated experimentally. The single-factor analysis is performed to explore the individual influence of different variables, and the comprehensive effect is conducted by the gray relational analysis. Furthermore, three surrogate models, including the response surface model, the Gaussian process model, and the radial basis function model, are conducted to parameterize the temperature behavior. On this basis, the multiobjective optimization functions are established and optimized by considering the maximum temperature, temperature difference, and accessories mass ratio. The results suggest that the optimized liquid-cooling system achieves high cooling efficiency and is lightweight compared with other liquid-cooling systems. The maximum temperature can be controlled below 36 °C, while the temperature difference is limited to 0.65 °C at a 3-C discharge rate. Besides, the accessories mass ratio of the battery module is declined to 10.25%.