Experimental and Numerical Study on Thermal and Energy Management of a Fast-Charging Lithium-Ion Battery Pack with Air Cooling

To comprehensively investigate the thermal and energy characteristics of air-cooling battery thermal management systems (BTMSs) during fast charging, a battery pack with 32 lithium-ion batteries was studied at various charge rates and air velocities. The evaluation parameters of the thermal performance during fast charging were experimentally obtained, and the energy characteristics of active air-cooling BTMSs with external and internal air circulation were analyzed and compared by combining experimental results and numerical models. The results show that, compared with the external air circulation system, the active air-cooling BTMS with internal air circulation can save up to 69.4% of the total energy consumption in a 30°C environment and 83.6% at 40°C. In the internal air circulation BTMS, the refrigeration energy consumption can constitute between 90.2% at maximum and 46.5% at minimum of the total energy consumption, and the remaining energy is consumed in supplying airflow. The energy consumed for each 1°C reduction of the maximum temperature rise decreases with increasing charge rate.