Experimental and modeling study of the combustion of ethyl methyl carbonate, a battery electrolyte

Abstract

Ethyl methyl carbonate (EMC) is one of the main constituents of the electrolyte in lithium-ion batteries (LIBs). To understand better fire events involving LIBs and try to prevent them, the combustion of EMC was studied experimentally, and the results were analyzed using modern detailed kinetics models. Shock tubes were used to collect ignition delay times (IDTs) and CO time histories, while laminar flame speeds were measured in a closed vessel. All experiments were carried out near atmospheric pressure. The shock tube experiments were performed for three equivalence ratios (0.5, 1.0, and 2.0) with the IDTs measured with “fuel-air” mixtures and the CO spectroscopic laser measurements in mixtures highly diluted in 99.25% He/Ar. Comparisons with results obtained for other linear carbonates typically found in LIBs, such as dimethyl carbonate and diethyl carbonate, are also presented. Numerical predictions from recent detailed chemical kinetics mechanisms (Takahashi et al., 2022, Grégoire et al., 2023) did not capture well the combustion behavior of EMC in some of our conditions. Sensitivity analyses suggest that EMC decomposition reactions and subsequent combustion chemistry of the formed intermediates, i.e. methanol and ethylene, still need improvement.