Laser-induced breakdown spectroscopy (LIBS) was used to characterize the ejecta released by lithium-ion (Li-ion) cells at thermal runaway conditions. Commercial AAA-size, rechargeable, 3.7 V, 350 mAh, Li-ion battery cells were heated in a N2 -atmosphere tubular chamber up to about 165 ℃ to induce thermal decomposition. Through measurements of the chamber internal temperature and LIBS emission intensities over, time the onset temperature of thermal runaway (≈143 ℃) and the duration of the cells outgassing (>40 minutes) were determined. Relatively high-intensity atomic emissions from C, F, H, Li, Na, and P were detected at different times during the heating experiments. The detection of analytes such as C and H was continuous over time. On the contrary, detection of F, Li, Na, and P was more irregular, indicating the presence of solid-phase analytes or analyte-bearing particles. A calibration scheme for estimation of the total mass/volume concentration of all carbon-based species sampled within the laser-induced plasma was developed.
Keywords: LIBS; Laser-induced breakdown spectroscopy; cell venting; lithium-ion battery cells; thermal runaway.