How do lithium battery fire extinguishing devices prevent fires before they start?
Publish Time: 2026-02-12
With the widespread adoption of electric vehicles, energy storage power stations, electric bicycles, and portable electronic devices, lithium batteries have become the mainstream power source due to their high energy density. However, their potential thermal runaway risk—which, once triggered, can cause violent combustion or even explosion within seconds—poses a serious challenge to public safety. Traditional "post-incident firefighting" methods are no longer sufficient to address the suddenness and re-ignition potential of lithium battery fires. Lithium battery fire extinguishing devices no longer focus solely on "extinguishing the fire," but rather employ a four-pronged strategy of "early detection—precise early warning—active suppression—long-term prevention" to truly prevent fires before they start.1. Multi-parameter fusion sensing: Precisely capturing anomalies in the early stages of thermal runawayLithium battery thermal runaway typically goes through four stages: "gas production—temperature rise—smoke—fire." The first two stages are the golden window for intervention. Lithium battery fire extinguishing devices integrate multi-dimensional sensors for temperature, smoke, combustible gases, and voltage anomalies to construct a composite early warning system. For example, when the temperature of a single battery cell abnormally rises to 60–80°C accompanied by the release of trace amounts of characteristic gases, the system can identify this as a precursor to thermal runaway, far earlier than the appearance of open flames. Some high-end devices even employ infrared thermal imaging or fiber optic temperature measurement technology to achieve blind-spot-free monitoring of hot spots inside the battery module, with an early warning response time 5–10 minutes in advance, providing crucial time for intervention.2. Millisecond-level activation and directional spraying: Precisely suppressing initial fire sourcesOnce the risk is confirmed, the fire extinguishing device can activate within 100 milliseconds, directly spraying the extinguishing agent onto the thermally runaway battery cell through nozzles pre-embedded inside the battery pack or between modules. Unlike traditional full-pack flooding spraying, modern lithium battery fire extinguishing devices use "point-to-point" directional release technology to ensure efficient coverage of the core of the fire source. Commonly used extinguishing media such as perfluorohexanone, fine water mist, or composite aerosols not only rapidly cool the battery but also interrupt chain chemical reactions. Experiments show that perfluorohexanone can reduce the surface temperature of a battery cell from 500℃ to below 150℃ within 3 seconds, effectively blocking heat spread.3. Long-lasting Chemical Inhibition: Breaking the "Reignition Curse" of Lithium BatteriesThe most intractable problem in lithium battery fires is reignition—even if the open flame is extinguished, the residual high temperature can still ignite adjacent cells. To address this, advanced fire extinguishing devices introduce a dual-effect mechanism of "cooling + inhibition." For example, after perfluorohexanone vaporizes and absorbs heat, its decomposition products can form a free radical trapping layer, continuously inhibiting the electrolyte decomposition reaction; and some composite fire extinguishing agents also contain film-forming components that can form a heat-insulating barrier on the cell surface, delaying heat accumulation. Actual test data shows that systems equipped with long-lasting inhibition functions can reduce the reignition rate by more than 90%, truly achieving "one-time extinguishing, long-term stability."4. Intelligent Linkage and Remote Alarm: Building a System-Level Safety Defense LineAutomatic fire extinguishing devices do not operate in isolation but are deeply integrated into the battery management system and the vehicle/power station control platform. Once triggered, the system not only initiates fire suppression but also simultaneously cuts off the high-voltage circuit, closes ventilation ducts, sends fault location information to the cloud management platform, and triggers audible and visual alarms. In energy storage power stations, it can also link with the air conditioning system to lower the ambient temperature or activate smoke extraction devices to dilute the concentration of combustible gases. This multi-system collaboration upgrades single-device protection to a holistic safety ecosystem.5. Modular Design Adapts to Diverse Scenarios: From Electric Vehicles to Home Energy StorageFor different application scenarios, the lithium battery fire extinguishing device adopts a modular architecture. Electric vehicle battery packs embed micro-fire extinguishing units, which are small in size and respond quickly; large energy storage cabinets are equipped with distributed pipeline systems covering hundreds of cells; while home energy storage devices integrate small, unified devices, balancing safety and aesthetics. Regardless of the form, the core logic remains the same: identify risks before a fire occurs, intervene precisely in the initial stage, and prevent secondary disasters afterward.The lithium battery fire extinguishing device is moving from "passive fire suppression" to "active defense." Through intelligent front-end sensing, precise fire suppression response, long-lasting suppression effect, and system-wide collaborative coordination, it is no longer the last line of defense, but a safety guardian throughout the entire battery lifecycle. In today's accelerating energy transition, this ability to "prevent fires before they start" is a key cornerstone for building a trustworthy, reliable, and sustainable electrochemical energy system.
