Electric vehicle adoption depends heavily on reliable battery thermal management systems, which directly influence performance, lifespan, and safety. Lithium-ion batteries generate substantial heat during discharge cycles, and inadequate cooling can reduce efficiency and accelerate degradation. Researchers recently conducted a detailed computational analysis of thermal performance in a 5×5 cylindrical battery pack using air cooling, comparing conventional circular inlets with an optimized bell-shaped inlet design.
The study employed three-dimensional conjugate heat-transfer modeling in ANSYS Fluent to evaluate performance across multiple discharge rates (0.5C to 3C) and inlet air velocities (5 to 13 m/s). Results demonstrated significant improvements with the bell-shaped inlet configuration. At maximum air velocity (13 m/s) and 1C discharge rate, peak battery temperature decreased from 32.2°C to 30.1°C—a 6.52% reduction. Performance gains were more pronounced at higher discharge rates; at 2C, maximum temperature fell from 50.8°C to 42.5°C, representing a 16.34% improvement. Temperature uniformity also improved, with inter-pack temperature differentials dropping from 19.7°C to 17.5°C.
The enhanced thermal performance stems from superior airflow redistribution through inter-cell passages and reduced hotspot formation. The bell-shaped inlet geometry facilitates more uniform air distribution, preventing localized overheating that typically occurs at pack peripheries. This approach is particularly valuable for light-duty EV applications, offering a simple, lightweight solution requiring minimal structural modifications.
The findings highlight how strategic cooling design can extend battery cycle life, improve charging efficiency, and enhance vehicle safety margins—all critical factors as OEMs push toward higher energy density packs and faster charging protocols. Such innovations support the industry's push for cost-effective thermal management without adding substantial weight or complexity, making them attractive for near-term vehicle platforms.
