Electrochemical performance and thermal stability of 18650 lithium-ion battery with water mist after high-temperature impact

Exposure of LIB to high temperatures may cause certain damage or even fail to work. In this study, the elec-trochemical performance, the thermal stability and the critical heat of 18650 LIBs with/without water mist after high-temperature impact are experimental investigated. The results demonstrate that water mist raises the critical temperature of battery damage by about 40 C. With increasing temperature, the electrochemical per-formance of the battery decreases, primarily caused by loss of lithium-ion. Moreover, water mist also improves the thermal stability of batteries after high-temperature impact, as demonstrated by the higher onset temperature of thermal runaway and activation barriers. Under the use of water mist, the critical heat that the battery per-formance is not affected and the critical heat for battery damage are obtained based on the increase and dis-tribution of temperature and double integral, which are 2489.46 & PLUSMN; 47.7 J and 4777.63 & PLUSMN; 71.55 J, respectively. This work reveals that water mist could alleviate the damage to the battery caused by high-temperature impact, but when the heat exceeds the critical heat, the damage is irreversible. These findings could provide suggestions for the use of water mist in the thermal safety design of batteries in the future.