How do lithium battery fire extinguishing devices achieve a dual fire suppression effect of rapid cooling and chemical inhibition when dealing with lithium battery thermal runaway?
Publish Time: 2026-01-31
With the widespread use of electric vehicles, energy storage systems, and portable electronic devices, the safety of lithium-ion batteries has become increasingly prominent. Once an internal short circuit, mechanical damage, or overcharging and over-discharging occurs, the battery is highly susceptible to triggering "thermal runaway"—a self-accelerating exothermic reaction that can raise the temperature to hundreds of degrees Celsius within seconds, releasing flammable gases, igniting open flames, or even causing an explosion. Traditional fire extinguishing methods have limited effectiveness against lithium battery fires. Lithium battery fire extinguishing devices, by integrating two core technologies—rapid physical cooling and efficient chemical inhibition—build a dual defense against thermal runaway, significantly improving fire suppression efficiency and preventing reignition.1. Rapid Cooling: The Key to Interrupting the Chain Reaction of Thermal RunawayThe essence of thermal runaway is a chain reaction involving multiple exothermic reactions, including the decomposition of the cathode material, electrolyte combustion, and SEI film collapse. To terminate this process, the battery temperature must be rapidly reduced below the critical point. Lithium battery fire extinguishing devices commonly employ high specific heat capacity cooling media to achieve rapid cooling. For example, fine water mist systems generate micron-sized water droplets through high-pressure nozzles, which rapidly vaporize upon contact with the high-temperature battery surface, absorbing a large amount of latent heat. Simultaneously, the water vapor dilutes the oxygen concentration. More advanced solutions utilize phase change materials or low-temperature inert gases to achieve millisecond-level localized cooling without conducting electricity, effectively preventing the heat spread from individual cells to adjacent modules.2. Chemical Inhibition: Interrupting Free Radical Chain Combustion ReactionsCooling alone is insufficient to completely extinguish lithium battery fires because continuous electrochemical reactions and flammable gas releases persist internally. Therefore, fire extinguishing devices must also possess chemical inhibition capabilities. Currently, mainstream technologies include perfluorohexanone, aerosols, and composite dry powders. These extinguishing agents actively capture hydroxyl and hydrogen free radicals generated during combustion, interrupting free radical chain reactions. For example, perfluorohexanone molecules decompose at high temperatures to produce active fluorine free radicals, which combine with active particles in the flame to form stable compounds, thereby "extinguishing" the flame in the gas phase. Meanwhile, it is non-conductive, residue-free, and environmentally friendly, making it particularly suitable for environments with precision electronic equipment.3. Synergistic Effect: Cooling + Inhibition = Preventing ReignitionA single mechanism is often insufficient to address the complexity of lithium battery fires. Advanced fire extinguishing devices emphasize the spatiotemporal synergy of cooling and chemical inhibition. For example, in the early stages of a fire, the system first releases chemical inhibitors to quickly extinguish open flames; subsequently, it continuously sprays cooling media to provide a prolonged "immersion" cooling of the battery pack, stabilizing the internal temperature below a safe threshold and preventing thermal runaway from being triggered again due to residual heat or internal short circuits. Some intelligent systems also integrate a temperature feedback loop, automatically initiating secondary spraying when a temperature rise trend is detected, achieving closed-loop management of "dynamic temperature control + precise flame suppression," fundamentally eliminating the risk of reignition.4. System Integration: End-to-End Optimization from Detection to ResponseEfficient dual fire extinguishing effects rely on close coordination between front-end sensing and back-end execution. Modern lithium battery fire extinguishing devices are typically linked to multi-sensor networks, triggering early warnings and initiating pre-spraying in the early stages of thermal runaway. Meanwhile, the device's structural design emphasizes redirection coverage and penetration capabilities, ensuring that the extinguishing medium can penetrate deep into the gaps between battery modules and reach the core of the heat source. In energy storage power stations or electric vehicle battery compartments, a strategy of zoned isolation combined with localized fire suppression is often employed to avoid resource waste and secondary damage caused by a "one-size-fits-all" approach to fire suppression.Faced with the high-risk and rapidly evolving nature of lithium battery thermal runaway fires, relying solely on traditional firefighting methods is no longer effective. Lithium battery fire extinguishing devices rapidly cool down the battery to cut off energy supply, combined with chemical inhibition to interrupt the combustion chain reaction, forming a "two-pronged" approach to fire suppression. In the future, with the deep integration of intelligent sensing, new extinguishing media, and thermal management technologies, these devices will further advance towards the goal of "early detection, precise intervention, and zero reignition," safeguarding the safety of the new energy era.
