Simulation-Based Evaluation of Battery Thermal Management Systems for Cylindrical Li-Ion Batteries in Electric Vehicles

Cylindrical lithium-ion batteries are widely used in electric vehicles due to their high energy density and compact size. However, effective thermal management is crucial for their optimal performance and safety. This study evaluated the thermal performance of a battery pack by simulating three cooling strategies: air cooling, water-based liquid cooling, and ethylene glycol-based liquid cooling using CFD simulations in Ansys Fluent. The results demonstrated that ethylene glycol-based liquid cooling achieved the most uniform temperature distribution within the battery pack, with a minimum temperature of 293.2 K and a maximum temperature of 306.6 K. This indicates superior heat dissipation capabilities and improves thermal management compared to the other cooling methods. These findings provide valuable insights for optimizing battery pack design and enhancing the overall performance and lifespan of electric vehicles. Major Findings: The study found that ethylene glycol-based liquid cooling (Geometry 2) was the most effective cooling strategy, achieving a uniform temperature distribution with a minimum of 293.2 K and a maximum of 306.6 K. In contrast, air and immersed cooling methods exhibited limitations such as uneven temperature distribution, excessive heat absorption at the inlet, and insufficient heat removal at the outlet, which could lead to hotspots and accelerate battery degradation. Geometry 2 with ethylene glycol significantly improved temperature uniformity, reduced temperature variations, and minimized the risk of thermal runaway, ultimately enhancing battery performance and lifespan.