Thermal performance of phase change material integrated prismatic heat sinks for electric vehicle batteries: experimental and neuro-fuzzy analysis

Thermal instability in prismatic lithium-ion batteries limits the lifespan, performance, and safety of electric vehicles. This study experimentally evaluates aluminium prismatic heat sinks with fin volume fractions of 0 %, 5 %, 10 %, and 14 %, filled with paraffin-based phase change material (melting point 36.5 °C), under heat inputs ranging from 8 to 23 W to simulate battery discharge. The 10 % fin configuration demonstrated the best performance among the tested cases. Incorporation of phase change material extended the time to reach 50 °C from 13 min (without phase change material) to 50 min. A 400-minute test at 20 W confirmed uniform temperature distribution within the molten phase change material, enabled by enhanced conduction and natural convection. To complement the experiments, an adaptive neuro-fuzzy inference system model was developed to predict (i) the time to reach 36 °C and (ii) the temperature after 120 min, using fin volume and heat input as input variables. The model achieved high accuracy, with an average absolute error of 6.50 % (3.78 min) for the time to reach 36 °C and 1.90 % (1.28 °C) for the temperature after 120 min. This combined experimental–computational approach minimizes the need for physical prototyping and delivers scalable design insights for efficient passive thermal management of prismatic battery modules. The integration of PCM-finned prismatic heat sinks with advanced modelling represents a novel contribution, offering practical pathways for the development of next-generation electric vehicle batteries.