Thermal oxidation characteristics for smoke particles from an abused prismatic Li(Ni_0.6Co_0.2Mn_0.2)O₂ battery

Smoke particles form a major component of flammable and toxic emissions from a failed battery. Insight into smoke-particle ignition mechanisms and reactions with air can provide a better basis for analyzing thermal hazards. This paper reports studies of thermal abusive tests for a 50-Ah prismatic Li(Ni_0.6Co_0.2Mn_0.2)O₂ battery in an inert experimental atmosphere without fire or any spark spots. By combined thermogravimetic (TG), differential thermal analysis (DTA), and Fourier transform infrared (FTIR) tests, the thermal oxidation characteristics and oxidizability of smoke particles have been analyzed and assessed. The results show marked size effects on the thermal oxidizability of the particles, which are divided into five samples by size. Fine particles suffer greater fractional mass loss fraction than coarse particles, also a larger mass transformation rate, greater absorption peak for CO₂, a smaller value of differential thermal gravimetric curve, and higher enthalpy. These characteristics can be attributed to the fact that specific surface area gets larger as particle size becomes smaller. This work deepens the understanding of the ignition mechanism for smoke particles and provides references for battery system fire risk assessment and its hazard prevention.