Lithium-ion batteries are widely used in electric vehicles and energy storage power stations due to their high energy density and long cycle life. However, the fire risk caused by thermal runaway remains a core challenge in the field of safety. Lithium battery fire extinguishing devices utilize multi-dimensional, highly sensitive early detection technologies, combined with intelligent algorithms and coordinated control, to construct a fire prevention and control system covering the entire battery lifecycle, providing crucial protection for the safe application of lithium-ion batteries.
Early detection of lithium-ion battery fires needs to overcome the limitations of traditional single-parameter monitoring. While traditional temperature sensors can capture changes in battery surface temperature, they are easily affected by environmental factors and cannot reflect the internal chemical reaction process of the battery. Modern lithium battery fire extinguishing devices employ multi-sensor fusion technology, integrating temperature, gas, smoke, pressure, and electrical parameter monitoring modules to form a three-dimensional sensing network. For example, gas sensors can detect characteristic gases of thermal runaway, such as hydrogen and carbon monoxide, in real time, with sensitivity down to the ppm level; smoke detectors capture tiny particles generated by the decomposition of electrolyte inside the battery through laser scattering or photoelectric effects, achieving very early fire warnings.
Multi-feature fusion algorithms are the core of improving the accuracy of early warnings. The thermal runaway process of lithium batteries involves dynamic changes in multiple parameters such as temperature, voltage, internal resistance, and gas concentration. Judging by a single parameter threshold can easily lead to false alarms or missed alarms. A lithium battery fire extinguishing device uses machine learning algorithms to establish a multi-parameter correlation model, which can identify early characteristic patterns of thermal runaway. For example, when an abnormal temperature rise is accompanied by a surge in carbon monoxide concentration, the system will determine it as the early stage of thermal runaway, rather than simply overheating or gas leakage. This algorithm, trained on massive amounts of historical data, can adapt to the characteristics of different types of lithium batteries, significantly reducing the false alarm rate.
Very early detection technology significantly advances the warning time. Traditional detection methods often trigger alarms only after the battery temperature reaches a critical value or an open flame appears, at which point the fire is difficult to control. The new lithium battery fire extinguishing device uses cutting-edge technologies such as ultrasonic detection and electrochemical impedance spectroscopy to intervene in the early stages of the thermal runaway chain reaction. For example, ultrasonic sensors can detect signs of electrode material decomposition before temperature rises by monitoring changes in acoustic impedance caused by gas generation inside the battery. Electrochemical impedance spectroscopy, on the other hand, analyzes the frequency domain characteristics of the battery's internal resistance to capture microscopic processes such as SEI film damage and lithium dendrite growth, achieving "pre-ignition" of thermal runaway.
Seamless linkage between detection devices and fire extinguishing systems is crucial for prevention and control. Lithium battery fire extinguishing devices typically integrate detection units, control units, and actuators to form a closed-loop control system. When the detector issues a warning signal, the control unit immediately initiates an emergency procedure: on the one hand, it cuts off the battery charging or discharging circuit to prevent further deterioration of thermal runaway; on the other hand, it activates the fire extinguishing device to precisely release inhibitors at the fire location. For example, perfluorohexanone fire extinguishing agents can cover the fire source within seconds, extinguishing the flames through a dual action of physical cooling and chemical inhibition, while preventing battery reignition.
Distributed detection networks enhance the safety of large-scale energy storage systems. In scenarios such as energy storage power stations, lithium batteries are densely arranged in a modular form, and localized thermal runaway can trigger a chain reaction. The lithium battery fire extinguishing device employs a layered deployment strategy, installing composite detectors at the battery pack level to monitor the status of individual cells in real time; and setting up a centralized detection unit at the compartment level to coordinate overall safety. This grid-like monitoring system can quickly locate fire sources and upload data to a cloud platform via CAN bus or wireless communication for remote monitoring and intelligent decision-making.
Early detection and warning technology for lithium battery fire extinguishing devices is evolving towards higher sensitivity and lower false alarm rates. With improved sensor accuracy, algorithm optimization, and the application of new materials, future lithium battery fire extinguishing devices will achieve "zero-delay" identification of thermal runaway risks, building a solid last line of defense for the safe application of lithium batteries.
