Experimental study on the effect of passive retardation method for thermal runaway mitigation of lithium-ion battery

Abstract

To delay and suppress the thermal runaway of 18650-type lithium-ion battery, three TRRs (thermal runaway retardants) with various mitigation mechanisms were proposed, and the results were compared to the commonly used thermal management material PA (paraffin). A 200 W heating rod was used to trigger thermal runaway, the flame height, battery temperature, and mass loss were recorded and the suppression effects of different materials were discussed. The results show that PA delays the onset of thermal runaway, however, the higher flame, faster temperature rise, and longer burning time are all a sign of increased danger. TRRH (phenoxy cyclophosphazene) with radical capture effect enables the reduction in flame height and peak temperature by 60.87% and 30.31% compared to a single battery. However, the lack of heat absorption prevents TRRH from reducing the battery surface temperature. TRRM (magnesium hydroxide) and TRRS (sodium acetate trihydrate) have a positive effect on the reaction rate, temperature rise, and flame of the battery. TRRS performs better, and lowering the battery surface temperature to below 400 °C and delaying the onset of thermal runaway by more than 25 min. This study brings novelty to the thermal runaway suppression of lithium-ion batteries, especially from the perspective of pre-filled materials.