Enhanced performance in mixture DMSO/ionic liquid electrolytes: Toward rechargeable Li -O2 batteries

A mixture electrolyte based on dimethyl sulfoxide (DMSO) and 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethylsulfonyl)imide, [BMP][NTf2], with excellent reversibility of oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) has been reported for Li-O2 batteries. The effect of the mixture electrolyte on current density, oxygen solubility, diffusion coefficient and oxygen reduction reaction (ORR) mechanism was investigated. The presence of [BMP][NTf2] increases the solubility of oxygen and while DMSO improves the reversibility of ORR and OER by facilitating the solubility of Li2Ox. Cyclic voltammetric studies showed that mixed electrolyte showed significantly enhanced current density and reversibility for ORR and OER compared to pure DMSO or [BMP][NTf2].