Thermal Performance Analysis of Lithium-Ion Battery Pack by Integrating Phase Change Material With Convective Surface Cooling Technique

Abstract

The thermal behavior of the lithium-ion battery (LIB) pack has a substantial impact on its cycle life, charge-discharge characteristics, and safety. This research presents a comparative experimental analysis of the thermal performance of a lithium-ion battery pack designed for an electric bike, both with and without using phase change material (PCM). In both cases, a novel approach of passing air over the battery pack casing is employed to induce forced convection conditions, ensuring compliance with IP67 standards. The study examines the temporal variation of battery pack temperature at various constant discharge rates. The study demonstrated that the forced convection cooling method was more effective in maintaining the battery pack maximum temperature (<i>T</i><sub>max</sub>) below the optimal and safe temperature limits as compared to the natural convection cooling method in the absence of phase change materials. With the incorporation of PCM, the <i>T</i><sub>max</sub> value is found to be 12.4°C lower than that of the baseline case. Furthermore, the temperature homogeneity within the battery pack was significantly enhanced, as the maximum temperature difference [(Δ<i>T</i>)<sub>max</sub>] was reduced by 3.3°C compared to the baseline case. The combination of natural convection cooling and PCM is the most effective in controlling the battery temperature at 0.75 C discharge rate. The experimental data presented in this work could provide a good practical insight into the battery thermal management for electric bikes application.