Study on Material Selection and Thermal Performance of Phase Change Materials for Lithium-Ion Batteries Adapted to Topology-Optimized Fins

Abstract

Thermal management of lithium-ion batteries is critical to ensuring their safe and efficient operation. Phase change materials (PCM) and heat transfer enhancement with fins are mainstream technical solutions at present. In this paper, a topology-optimized fin-PCM composite thermal management model is constructed for 2×3 array 18650 lithium-ion batteries. The thermal performance of three PCMs is compared via numerical simulation, and the influences of phase change temperature, latent heat and thermal conductivity on the maximum battery temperature, maximum temperature difference and liquid fraction are analyzed. The results show that PCM 2 achieves the optimal balance among latent heat capacity, phase change temperature and thermal conductivity under 3C and 4C discharge conditions. At the end of discharge, the maximum temperature of PCM 2 is reduced by 2.49% and 6.17% (3C), 8.54% and 6.12% (4C) compared with PCM 1 and PCM 3, respectively. Meanwhile, PCM 2 presents a stable liquid fraction variation and the best thermal buffering effect. This study can provide a reference for material selection and structural design of passive thermal management systems for high-rate lithium-ion batteries.