Thermal analysis of air-cooled cylindrical battery for improving electric vehicle performance: CFD analysis

Electric vehicles (EVs) have become more popular in recent years due to their various strong merits like pollution and rising fuel prices every day. The demand for EVs is rapidly increasing across the world due to advanced safety in thermal management in lithium-ion battery technology. Lithium-ion batteries are widely used in electric vehicles due to their various advantages, such as higher energy density, a large power-to-weight ratio, a longer life cycle, etc. The BTMS is essential for electric vehicles to improve their overall performance of electric vehicles. A recent study done numerically investigation of the thermal performance of a 5 × 5 cylindrical 18650 lithium-ion battery pack using air cooling. The performance evaluates a comparison of a circular and bell-shaped air inlet. A three-dimensional conjugate heat-transfer model was developed in ANSYS Fluent to analyse the effects of discharge rate at 0.5 C,1 C, 2 C, and 3 C and inlet air velocity from 5 m/s to 13 m/s. The circular inlet with a 20 mm diameter is considered as the reference configuration, while the proposed bell-shaped inlet was evaluated under identical operating conditions. At the 13 m/s air inlet velocity, the bell-shaped inlet reduced the maximum battery temperature from 32.2 °C to 30.1 °C at 1 C, corresponding to a 6.52% reduction, while at 2 C the maximum temperature reduced from 50.8 °C to 42.5 °C, corresponding to an 8.3 °C or 16.34% reduction. At 2 C, the temperature difference across the battery pack decreased from 19.7 °C to 17.5 °C. The improved thermal performance is attributed to more effective airflow redistribution through the inter-cell passages and reduced hotspot formation. The proposed configuration therefore provides a simple and lightweight approach for improving thermal control of cylindrical lithium-ion battery packs for light-duty EV applications.