Experimental and detailed kinetics modeling study of the fire suppressant properties of di(2,2,2trifluoroethyl) carbonate

To reduce the flammability of lithium-ion battery electrolytes, the fire suppressant effect of di(2,2,2trifluoroethyl) carbonate (DtFEC) was investigated experimentally and numerically using a new detailed kinetics model. DtFEC has a structure similar to diethyl carbonate (DEC), which is a very common component of battery electrolytes. This similar structure should allow for an integration of the fire suppressant without excessive degradation of the battery performance. To validate the model and assess the fire suppressant potential of DtFEC, several kinds of experiments were performed around atmospheric pressure. The high-temperature chemistry of DtFEC was investigated in shock tubes by measuring ignition delay times for a DtFEC/O₂/Ar mixture and by measuring the CO formation during its pyrolysis using a laser absorption diagnostic. DtFEC's fire suppressant potential was assessed by measuring the effects of a small DtFEC addition on the ignition delay times and laminar flame speeds of well-known fuels, namely H₂ and CH₄. A model was assembled using a well-validated and modern base mechanism (NUIGMech1.1) coupled with existing chemistry for fluoroalkanes. Using ab-initio calculations, the DtFEC module and corresponding thermodynamics data were implemented. The resulting model performs well at predicting the global kinetics data (ignition delay time, laminar flame speed), but improvements on CO time-history profiles are still necessary.