Abstract: The suppression effect of aerogel?based fire extinguishing agent on thermal runaway of lithium?ion battery has been investigated through comparative experiments. The thermal runaway characteristics of fully charged 100 Ah lithium iron phosphate batteries have been studied, and three inflection points were identified as the guidance for the application of fire extinguishing agents. The fire mitigation effect of aerogel?based fire extinguishing agent and water mist was compared under same condition. Results show that both agents exhibit similar cooling efficiency and thermal runaway can be effectively mitigated when released before battery ignition. The aerogel?based fire extinguishing agent shows more excellent fire suppression effect. Once attach to the high temperature surface, the agent will form dense foam and can effectively block oxygen. In the case of thermal runaway, the aerogel?based fire extinguishing agent can significantly shorten the duration of jet fire, leading to the reduced fire hazard.

Key words: lithium?iron phosphate battery, thermal runaway characteristics, aerogel?based fire extinguishing agent, water mist, energy storage battery, jet fire