Singlet Oxygen Formation during the Oxygen Reduction Reaction in DMSO LiTFSI on Lithium Air Battery Carbon Electrodes

Abstract

Formation of singlet oxygen,1O2, during the O2 electroreduction reaction (ORR) on carbon electrode in Lithium bis‐(tri‐fluoromethylsulfonyl)imide (LiTFSI) dimethyl sulfoxide (DMSO) electrolyte has been detected “in‐operando” by fluorescence quenching of 9,10‐dimethylanthracene, DMA. Furthermore, the formation of 1O2 during ORR requires Li+ ions, while in the presence of the efficient physical 1O2 quencher, sodium azide, DMA fluorescence quenching is negligible. Addition of Li+ ions to superoxide solution in DMSO formed by ORR enhances DMA quenching, which is a proof that 1O2 results from superoxide bimolecular disproportionation.