Thermal–Economic Optimization of PCM Recovery in Lithium-Ion Battery Thermal Management Systems Using Response Surface Methodology

This study addresses the challenge of the recovery and solidification process of phase change materials (PCM) in lithium-ion battery thermal management systems, considering both time and cost factors. Using computational fluid dynamics (CFD) simulations and the response surface methodology (RSM), the recovery performance was optimized for three different configurations: pure PCM, PCM-sheet, and PCM-foam. The key variables examined include cooling media temperature (10–20 °C) and convective heat transfer coefficient (5–15 W/m 2 ·K). The results show that copper foam reduces solidification time by up to 10% compared to pure PCM. However, under optimal conditions (convective coefficient 13.8 W/m 2 ·K and cooling media temperature 12.7 °C), pure PCM demonstrates superior performance in terms of the time–cost index. The multi-objective optimization reveals a clear trade-off between efficiency and cost: while metal-enhanced systems accelerate recovery, they increase the time–cost index by up to 2.5 times. The RSM framework identifies the optimal solutions and indicates that pure PCM is preferable for cost-sensitive applications, while hybrid systems are better suited for cases where rapid cycling is critical. This research provides practical insights into achieving a balance between thermal performance and economic feasibility in PCM-based thermal management systems.