Utilization of liquid nitrogen as efficient inhibitor upon thermal runaway of 18650 lithium ion battery in open space

The thermal runaway (TR) of lithium-ion batteries (LIBs) has become a potential danger of serious fire and explosion, which threatens people's life and property safety. Therefore, the timely and effective methods are urgently needed to suppress this hazardous process. Therefore, it is of great significance to develop efficient TR inhibitors. Liquid nitrogen (LN) has been widely concerned as an efficient and environmentally friendly fire extinguishing medium. In this paper, TR device of LIBs in open space is investigated, and the effectiveness of LN in restraining the TR of LIBs is studied under different heating power, spray direction, state of charge (SOC) and spray time. The results show that LN has excellent inhibition effect on TR, and the mean cooling rate of LIBs surface temperature decreases with the increase of heating power. Vertical spraying is better than horizontal spraying for cooling and extinguishing. The average cooling rate of battery surface temperature decreases with the increase of SOC. The average cooling rate of battery surface temperature decreases with the shortening of the time.