Do fire blankets work on lithium battery fires?
Fire blankets have limited effectiveness on lithium battery fires due to the self-sustaining chemical reactions and high temperatures (exceeding 400°C) generated during thermal runaway. While they may temporarily smother flames by oxygen deprivation, lithium batteries internally produce oxygen and flammable electrolytes, allowing fires to reignite. Pro Tip: Use water immersion immediately for small lithium battery fires—it cools cells and disrupts reactions more effectively than smothering.
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Why can’t fire blankets fully extinguish lithium battery fires?
Lithium battery fires involve self-oxygenation and chain reactions that bypass traditional smothering methods. Fire blankets lack cooling capacity to halt internal thermal runaway, which sustains temperatures above 400°C.
Lithium battery combustion generates its own oxygen through decomposition of lithium metal oxides, rendering oxygen-deprivation tactics ineffective. The thermal runaway process creates a feedback loop: heat triggers electrolyte vaporization, which ignites and releases more heat. A fire blanket might suppress visible flames temporarily, but residual energy in cells often reignites the fire within minutes. For example, a 2023 lab test showed a covered 18650 cell reigniting twice within 15 minutes. Pro Tip: Pair fire blankets with continuous water application—the cooling effect extends containment time by 30-50%.
What alternatives work better than fire blankets?
Water immersion and Class D extinguishers outperform fire blankets by addressing both heat and chemical reactions. Large-scale tests show water reduces fire duration by 60% compared to smothering.
Water cools battery cells below thermal runaway thresholds (typically 80-120°C) while diluting flammable electrolytes. Though lithium reacts with water, the hydrogen gas risk is manageable in open spaces. Class D extinguishers with copper-based agents form a crust over burning cells, blocking oxygen and dissipating heat. For instance, a 228Ah LiFePO4 pack required 18L of water versus 3 fire blankets in controlled extinguishing trials. Pro Tip: Prioritize water access—every liter applied within the first minute reduces reignition probability by 25%.
| Method | Time to Extinguish | Reignition Risk |
|---|---|---|
| Fire Blanket | 2-5 mins | High (70%) |
| Water Immersion | 30-90 secs | Low (15%) |
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FAQs
No—thermal runaway pressures exceed 2,000 kPa, easily rupturing standard blankets. Use blast-resistant containers for critical battery storage.
How much water is needed for a phone battery fire?
Submerge the device in 5+ liters of water. Even small Li-ion cells require sustained cooling to prevent reignition.