Evaluation of Fire Spread and Suppression Techniques in Micro-Mobility Battery Packs

Abstract

Lithium-ion battery packs used in micro-mobility devices, such as e-bikes and e-scooters can lead to substantial safety hazards should a single cell go into thermal runaway. In this paper we explore the extent and severity of e-mobility battery fires resulting from a single cell thermal runaway failure and evaluate various suppression techniques a user may attempt to implement if they experience a battery fire at home. We tested a household water hose as well as different fire blankets deployed both before the forced thermal runaway event and after initiation. The water hose was unable to supply a sufficient amount of water to extinguish the thermal event, however, the average pack temperature was decreased and the cell-to-cell propagation rate was slowed. Neither fire blanket tested was able to contain the flames or debris ejected from the battery packs and both acted to hold in the heat from the event, increasing the temperature, rather than allowing it to dissipate. In addition, we also demonstrated how various design approaches, such as added thermal insulation between cells, can help prevent cell-to-cell propagation and reduce the severity of a battery pack failure.

Keywords

• lithium-ion battery
• e-mobility
• battery safety
• thermal testing
• battery abuse testing
• fire safety