Thermal Management of Lithium-Ion Batteries in Electric Vehicles: Comparative Analysis of Dielectric Fluids in Single-Phase Liquid Immersion Cooling Systems

Global warming and air pollution drive the transition towards electric vehicles (EVs), which are efficient and have minimal emissions compared to internal combustion engine vehicles. Lithium-ion batteries (LIBs) are the preferred power source for EVs due to their high energy density and longevity. However, the thermal performance of LIBs is a critical challenge, as temperature significantly impacts their efficiency, capacity, charging, and lifespan. This study investigates the thermal management of LIBs using direct liquid cooling with dielectric fluids to address these issues. A numerical analysis compares the thermal performance of various dielectric coolants—mineral oil, deionized water, and coconut oil—in a single-phase liquid immersion cooling setup for cylindrical ۱۸,۶۵۰ battery cells. The study evaluates temperature homogeneity and maximum temperature across different coolant flow rates. The results highlight the cooling effectiveness and practical considerations of each dielectric fluid, providing insights into optimizing LIB thermal management for improved safety and performance in EV applications