Multi-objective optimization of battery thermal management system combining response surface analysis and NSGA-II algorithm

To keep the operating temperature of lithium-ion batteries (LiBs) in the ideal range, a phase change material (PCM)/microchannel coupled battery thermal management system (BTMS) was proposed in this paper. The range of values for each factor was first determined by single-factor analysis. The significance of each factor on the response was then investigated by the response surface method (RSM), and the effect of interaction terms was analyzed. Finally, the proposed BTMS was optimally designed based on the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). Compared with the initial design, the maximum temperature of the optimal design was increased by 0.2 & DEG;C, but the maximum temperature difference and Pressure drop were reduced by 9.3% and 93.7%, respectively. In addition, the liquid phase fraction of PCM has increased by 25.9%. At the same time, the volume of the optimal design was reduced by 15.6% compared to the initial design. In the proposed BTMS, the liquid cooling plate was fitted to the largest surface of the prismatic LiBs, increasing the heat transfer area. Compared to the aluminum liquid cooling plate, PCM acts as a thermal buffer, avoiding significant temperature differences between LiBs along the coolant flow path and improving temperature uniformity.