Multi-objective optimization of integrated lithium-ion battery thermal management system

Battery thermal management system (BTMS) based on phase change materials (PCM) are demonstrating great performance in the field of high heat flux heat dissipation. However, traditional hybrid PCM modules focus too much on their thermal performance and ignore the weight issue, which greatly reduces their wide application. In this paper, a BTMS integrated air cooling channels, fins and PCM is proposed to improve the thermal performance of the battery. The maximum temperature (T-max), temperature difference (delta T) and weight (W) of BTMS are used as indicators for the evaluation of the battery performance. The balance between temperature uniformity and lightness of the lithium-ion battery pack is also analyzed according to the entropy weight-TOPSIS method. The results demonstrate that while the thermal performance of the battery pack is enhanced with PCM thickness (d) increases from 5 mm to 20 mm, the weight of the system increases significantly by 146.7 % as d increases. Besides, as fin height (l) increased from 5 mm to 65 mm, the liquid fraction increases by 20.4 %. According to the entropy weighting method analysis, the index weights of Tmax, & UDelta;T and W are 28.37 %, 26.64 % and 44.99 %, respectively. Furthermore, after TOPSIS algorithm search, d = 7.5 mm and l = 65 mm are the best structural parameters for BTMS, and the corresponding T-max, delta T and W of BTMS are 319.29 K, 0.0135 K and 5.13 kg, respectively.