A New Look at the Stability of Dimethyl Sulfoxide and Acetonitrile in Li-O2 Batteries

Dimethyl sulfoxide (DMSO) and acetonitrile (MeCN) have recently been highlighted as promising electrolyte solvents for Li-O2 batteries. Possible reactions between these two solvents and Li2O2 are here discussed using X-ray photoelectron spectroscopy to analyze surface of the Li2O2 powder after direct contact with the solvents for different times of exposure. The results indicated that Li2O2 decomposes DMSO solvents, whereas no indication of degradation of MeCN by Li2O2 was observed.