As electric vehicles permeate our daily life, and with significant advancements in energy density, safety is a growing concern. News coverage of spontaneous electric vehicle battery fires are frightening, especially when they occur in a garage or near a home. For this reason, detection of an off normal event, such as gas release, is necessary to give advanced warning for intervention. That is, advanced warning so that we may potentially stop the occurrence of thermal runaway, and thus a battery fire, and/or advanced warning to allow movement of individuals away from a dangerous situation.

This works utilized a gas sensing tool to quantify key metrics in early detection of gases emitted from battery cells in the pouch format. The times between the detection of an off normal event, venting, and thermal runaway were determined in a controlled environment and under abusive conditions. The importance of sensor proximity to the time between detection and an off normal event was evaluated. This testing used an array of sensors positioned throughout an abuse testing bay. Batteries with LFP or NMC cathodes were subjected to two abuse modes, external heating, and overcharge. The gas composition was verified by FTIR to rule out the possibility of early detection by some other substance, such as an adhesive. This work gives insight into the ability of gas detection to give advanced warning with different battery chemistries and failure modes.