Early Detection Technology for Lithium-Ion Battery Fires Using Raman LiDAR Sensors

This study examined the applicability of Raman LiDAR as a non-contact and remote technique for the detection of hydrogen gas released during lithium-ion battery fires in electric vehicles (EVs). A thermal runaway phenomenon was induced in the battery cells, and the hydrogen off-gas was continuously monitored. The results showed that approximately 1,400 ppm of hydrogen was detected within 2-3 min of ignition, and the concentration increased to a maximum of 4,850 ppm as combustion progressed. Distinct Raman signals for hydrogen were observed at approximately 390 nm, while Rayleigh scattering at 371 nm provided complementary insights into combustion stages and gas release behavior. These findings demonstrate that EV battery fires are not merely thermal events but also involve the release of large amounts of hydrogen, posing additional hazards. The proposed Raman LiDAR technique effectively overcomes the limitations of conventional contact-based sensors in open environments and enables the real-time monitoring of hydrogen under high-risk conditions. This study provides fundamental insights into strategies for enhancing EV fire safety and contributes to future efforts in safety management and standardization of hydrogen-based infrastructures.