Experimental Study on the Explosion Intensity of Lithium-Ion Batteries in Air and Helium Environments

Lithium-ion batteries are widely employed in electric vehicles. However, the batteries can generate heat during charging or discharging. Improper management of heat generation in the battery may cause thermal runaway and explosions. As a result, an efficient battery thermal management system (BTMS) is essential to reduce the risk of explosions. The purpose of this study was to investigate the thermal runaway characteristics of batteries at various states of charge (SOC) in both air and helium environments. Battery explosion in the controlled chamber was experimentally performed and analysed in this study. The influence of cloaking with air or helium and varying SOC on explosion intensity was examined. Surprisingly, the most intense thermal runaway, as represented by battery temperature, occurred in the battery with 75% SOC rather than the one with 100% SOC. This was because the battery with 100% SOC experienced considerable mass loss, leading to the dissipation of an enormous amount of heat into the chamber, resulted in a lower maximum battery temperature. The research also discovered that the surrounding environment significantly affected the severity and the explosion’s characteristics. The use of helium gas achieved the reduction of thermal runway intensity, while using air resulted in more violent explosion compared to helium. This was due to the existence of oxygen, resulting in higher combustion temperatures.