Experimental Study of Air-Cooling System for Thermal Runaway Prevention of Nickel-Manganese-Cobalt Oxide (NMC) Battery Cells in Electric Vehicles

Battery thermal runaway (BTR) is a critical safety concern in electric vehicles (EVs), where heat generated within the battery can spread to adjacent cells, potentially causing explosions. This study investigates 18650-type NMC cylindrical cells to develop strategies for preventing battery fires linked to internal short circuits (ISCs) and self-heating, which can lead to BTR. We analyzed the impacts of battery surface temperature, blower speed, and cooling duration on preventing BTR. An air-cooling system was utilized to maintain surface temperatures at 90 ℃, 95 ℃ and 100 ℃, with air velocities at 1.92 m/s and cooling times of 5, 10, and 15 minutes. While BTR occurred with insufficient cooling time, cells cooled for at least 10 minutes at 90 ℃ and 95 ℃ showed no BTR signs. Importantly, at 100 ℃, no ISCs were observed after 15 minutes of cooling, demonstrating the effectiveness of proper cooling in preventing BTR.