Evaluating Fire and Smoke Risks with Lithium-Ion Cells,\nModules, and Batteries

The study included\ncharacterization of the components of fire and\nsmoke during thermal runaway for NMC and LFP cells, modules, and batteries\nand to determine if the size and volume of fire and smoke released\nscaleup linearly when one goes from the cell to module and then to\na battery configuration for the same cathode chemistry. Thermal runaway\ntests were conducted in ambient as well as inert environments to characterize\ngas release with and without combustion. During thermal runaway, the\ntest articles exhibited fire, smoke, or both. Gas analysis exhibited\nhydrocarbons as well as hydrogen and carbon dioxide that could accumulate\nabove the lower flammability limit (LFL) of the gas mixture if released\ninto an enclosure. The nature of fire and volume of smoke released\ndo not always scale linearly with an increasing number of cells, showing\nthat testing in the relevant configuration and environment is imperative.\nA good understanding of gases released into a certain enclosed space\nwill help with safer vent and deflagration designs and provide a warning\nto first responders and firefighters of the expected nature of gases.