Abstract: Abstract: To ensure the safe development of the electrochemical energy storage industry, an "immersed" battery fire protection system was designed and experimented for the lithium-iron phosphate battery system. The experiment uses overcharge to trigger the thermal runaway of the battery, accompanied by the burning of open fire, and studies the fire suppression effect of the "immersed" fire protection system of the battery pack in the design fire scenarios. The experiment results show that the "immersed" fire protection system can not only extinguish the fire quickly, but also effectively inhibit the heat spread of lithium-iron phosphate battery, and ensure the safety of lithium-iron phosphate battery system.

Key words: electrochemical energy storage, lithium-iron phosphate battery, fire protection system, "immersed" system