By: Islam El-Sakka
The industry is moving toward expanding its response to lithium battery fires by deploying unmanned reconnaissance systems and broadening detection scope to include the phase before visible flames appear. Detecting thermal runaway faces significant challenges given that changes in voltage and temperature remain minimal until just before the incident occurs.
Thermal Runaway Challenges and Residual Battery Risks
The thermal runaway phenomenon is a major cause of battery fires and is difficult to monitor early. Moreover, residual batteries pose a continuous risk after a fire is extinguished, as they can reignite, making human entry into sites perilous. Current safety systems rely on the flame appearance phase, while fires actually begin prior to that as a result of charge accumulation, temperature rises, electrolyte decomposition, and gas leakage.
Early Gas Sensing Technologies
The sector is working on developing detection systems based on sensing off-gases as an early warning method. Experiments by the Sandia National Laboratories in the United States have demonstrated the effectiveness of volatile organic compound (VOC) sensors, as they were able to provide a warning 7.1 minutes before thermal runaway occurred, allowing the electrical current to be cut off and ignition prevented. In South Korea, a research team from Hanyang University is working on developing methods to detect thermal runaway in pouch-type batteries that lack immediate safety valves.
Using Robotics in Reconnaissance Operations
After fires are extinguished, robotics are relied upon instead of human personnel to inspect sites. Examples include the 'Vine robot' developed by the National Fire Research Institute in cooperation with a research team led by Professor Yoo Ji-hwan from the Korea Advanced Institute of Science and Technology (KAIST). This robot is characterized by its ability to extend through openings without applying pressure to the ground, avoiding the risk of causing additional thermal runaway due to heavy weight, and it transmits real-time data on temperatures and battery deformation.
International Standards and Expansion of Application
The use of gas detection and unmanned reconnaissance technologies is expected to spread in battery cell factories, especially with the gradual adoption of international standards requiring gas monitoring. The insurance company FM Global has updated its standards to include automatic isolation of energy storage systems in the event of detected temperature rises or gas leaks, and the National Fire Protection Association (NFPA 76) standards in the United States require monitoring of electrolyte vapors in facilities with high battery density.
