Numerical investigation of battery thermal management using phase change material with nano additives

Efficient battery thermal management is vital for maintaining safety, efficiency, and lifespan of cylindrical lithium-ion batteries in automotive electric vehicles. This study presents an unsteady CFD investigation of 18,650 cylindrical cell with phase change materials. The novelty of this study lies in the comprehensive optimization of phase change material type ( n -eicosane and paraffin wax), PCM thickness (2, 4, 6, 8, and 10 mm), nanoparticle type (Al 2 O 3 and CuO), and nanoparticle concentration (3, 5, and 7 mass%) for an 18,650 cylindrical lithium-ion battery under identical discharge conditions. Unlike previous studies that primarily focused on individual design parameters, the present work evaluates their combined effects to identify an optimal passive battery thermal management configuration for electric vehicle applications. The computational domain comprises the battery, n -eicosane PCM, and aluminium enclosure with natural convection and bottom insulation, evaluated over a 20-min full discharge (3C) at an initial temperature of 300 K. It is observed that the total battery temperatures reduced from 385.87 K (without PCM and nano additives) to 310.27 K for 8 mm n -eicosane PCM, the reduction is 19.59% compared to without PCM and nano additives. Besides, the battery with n -eicosane PCM composed of 7% CuO nano additives reduced average battery temperature from 321.18 K to 315.88 K. At 1200 s, the liquid fraction of pure n -eicosane reached 0.3, whereas n -eicosane with 7% CuO nano additives showed a lower value of 0.16 at 1200 s, representing a 45.3% reduction in liquid fraction. The presence of PCM and nano additives shows superior thermal regulation and provides effective passive battery thermal management solution.