Comparative Analysis of Multi - Mode Cooling Techniques for Thermal Management of Lithium - Ion Batteries in Electric Vehicles

Abstract

In this investigation Five thermal management configurations were developed and analyzed, namely direct air cooling, direct water cooling, indirect U-bent tube water cooling, indirect U-bent tube ethylene glycol cooling, and a hybrid cooling system combining ethylene glycol with paraffin wax phase change material (PCM). The battery pack was modeled with a uniform volumetric heat generation rate of 50,000 W/m³ and an initial temperature of 300 K. Cooling media were supplied at a velocity of 1.5 m/s and an inlet temperature of 300 K. The simulations were performed under steady-state conditions to investigate temperature distribution, coolant flow behavior, pressure drop, and overall thermal performance. The results indicated that direct air cooling exhibited the highest battery cell temperature of 317.34 K, demonstrating limited heat dissipation capability. Direct water cooling achieved the lowest battery temperature of 305.26 K due to superior convective heat transfer. The indirect U-bent tube water and ethylene glycol cooling systems reduced battery temperatures to 313.17 K and 309.24 K, respectively. The hybrid ethylene glycol and PCM cooling system further improved thermal performance by reducing the battery temperature to 306.83 K through the combined effects of active liquid cooling and passive latent heat storage. Although direct water cooling provided the maximum heat removal capability, the hybrid cooling configuration offered the most balanced solution by combining effective temperature control, operational safety, thermal stability, and practical implementation advantages. The study concludes that the integration of paraffin wax PCM with ethylene glycol cooling significantly enhances battery thermal management performance and can be effectively utilized in electric vehicle battery packs and advanced energy storage applications. The proposed hybrid cooling system demonstrates strong potential for maintaining safe operating temperatures, improving battery reliability, and extending battery lifespan under continuous operating conditions.