Rate capability and Ragone plots for designing battery thermal management system based on phase change material

Phase change material (PCM), as a passive thermal regulation technology, is anticipated to mitigate the thermal challenges associated with anomalous temperature in lithium-ion batteries (LIBs). Nevertheless, the examination of its performance, i.e., energy and power density, has received limited attention in applications of battery thermal management system (BTMS). The primary aim of this work is to concentrate on the parametric optimization and performance assessment of BTMS utilizing PCM. Initially, a numerical model integrated paraffin/expanded composite and pouch battery is built and validated. Subsequently, a series of parametric studies are conducted to explore several aspects, including PCM type, expanded graphite loading, packing density, and PCM thickness. The thermal rate capability and Ragone plots are used to describe the specific energy and specific power of PCM. Based on that, the effects of PCM properties, geometry, and operating conditions can be effectively clarified. Furthermore, a multi-attribute decision making (MADM) method is introduced to aid variable selection. From analysis, the composite with PCM type of RT28, expanded graphite loading of 1–5 wt%, packing density of 700 kg m⁻³, and thickness of 3 mm is regarded as a suitable choice to achieve good performance. The present framework is helpful to provide guidance for PCM-based BTMS design.