Experimental study on suppressing thermal runaway propagation of lithium-ion battery modules by using liquid nitrogen: Influence of injection pipe diameter and position

This paper aims to address the safety threats posed by thermal runaway (TR) in lithium-ion battery (LIB) modules. The focus is on evaluating the effectiveness of liquid nitrogen (LN) in inhibiting TR and its propagation in large-capacity lithium iron phosphate batteries. The following conclusions emerge by adjusting the LN injection pipe diameter and position: The best effective heat utilization efficiency of 6.1 % and total heat absorption of 526.9 kJ from the LIB by LN observed for a 20 mm diameter and top injection position. For diameters of 15 or 25 mm, the total heat absorbed by LN from LIB and effective heat utilization efficiency is lower at 470 kJ/5.3 % and 433.1 kJ/4.9 %, respectively. Injecting LN from the top of the module exposes the LIB undergoing TR directly to LN, resulting in optimal suppression of TR propagation. However, in other positions (back, left), TR propagates to the second battery, with the total heat absorbed by LN from the LIB and the effective heat utilization efficiency being only 222.2 kJ/2.6 % and 298.5 kJ/3.3 %, respectively. This work would provide valuable guidelines for suppressing TR and TR propagation in LIB modules.