Early Detection of Mixed Volatile Organic Compounds to Circumvent Calamitous Li-Ion Battery Thermal Runaway

Abstract

Energy-dense lithium-ion batteries (LIBs) are susceptible to thermal runaway under abuse conditions yielding volatile organic compounds (VOCs) and gases below 100 °C; hence, early warning detection became very important. An impedance spectroscopy-based interdigitated platinum electrode with a submicron thick coating of poly(3,4-ethylene-dioxythiophene) polystyrene sulfonate (PEDOT–PSS) detected binary and ternary mixtures of VOCs. The impedance response of the sensor was recorded over the frequency range of 1 MHz to 1 Hz and analyzed for physical and chemical changes on interactions with binary and ternary VOCs. The single sensor was implemented to detect nine different binary mixtures and five different ternary mixtures chosen randomly of three VOCs, namely, ethyl methyl carbonate, methyl formate, and ethanol with 5, 15, and 30 ppm concentrations. Equivalent electrical parameters like charge transfer resistance and constant phase elements fitted with the goodness of fit value less than 10^–5, and the principal component analysis (PCA) method was used to distinguish responses into different classes. The application of multi-gas detecting sensors integrated with the battery management system (BMS) could facilitate cost-effective and efficient early warning before catastrophic thermal runaway events.