DFT Study on the Oxidation Mechanism of Common Cyclic Carbonates in the Presence of BF4-Anions

Oxidative decomposition reactions of common cyclic carbonates in the presence of BF4- anions were investigated using density functional theory. A polarized continuum model was utilized to model solvent effects in the oxidation of ethylene carbonate (EC) and propylene carbonate (PC) clusters. We have found that the presence of BF4- significantly reduces EC and PC oxidation stability, from 7.11 to 6.17 and from 7.10 to 6.06 V (vs Li+/Li), respectively. The sequence of EC and PC oxidative decomposition paths and the oxidative products were affected by the BF4- anion. The decomposition products of the oxidized ECBF4- contained CO2, vinyl alcohol, and acetaldehyde, while the decomposition products of the oxidized PC-BF4- contained CO2, acetone, and propanal, in agreement with the previous experimental studies. The oxidative decomposition reactions for PC-BF4- are compared with those for the isolated PC, PC2, PCClO4-, and PC-PF6-.