Experimental investigation on battery thermal management using phase change materials with different arrangement schemes

Thermal management is imperative for regulating battery temperature during operation. In this paper, lithium iron phosphate batteries were taken to experimentally investigate the battery thermal management system module utilizing phase change materials. Various phase change material (PCM) plates with uniform and gradient phase change material arrangements were produced by pressing phase change material powder to closely adhere to the battery. The experimental results illustrated that the phase change material plate had a good temperature uniformity effect on the battery, and this effect became more noticeable under high-rate battery discharge. Over 80% of the experimental group's the maximum temperature difference could be maintained within 3 degrees C. In addition, there was an optimal range for phase change material plate thickness, the effect of reducing the battery maximum temperature weakened and the efficiency of phase change material utilization decreased when the phase change material plate thickness exceeded a critical value. Specially, a gradient arrangement of the phase change material with different phase change temperatures had better cooling effect on the battery. Compared with uniform arrangement of PCM, the temperature difference with gradient arrangement of PCM was decreased by 55.6%, 70.8%, and 77.4% at 2C, 2.5C, and 3C discharge rates, respectively. To guarantee that the battery's high heat-generating areas can always be cooled by phase change material through latent heat absorption in the middle and later stages of discharge, phase change material with higher phase-change temperatures should be placed in these areas, which can coordinate the non-uniform heat generation of battery and prevent severe temperature rise as well as further reduce the maximum temperature difference. The findings presented in this study provide new insights for designing a battery thermal management system utilizing phase change material.