Organic radicals for the enhancement of oxygen reduction reaction in Li-O2 batteriesElectronic supplementary information (ESI) available: Methods section and synthesis, supporting cyclic voltammetry data and UV-Vis spectra. See DOI: 10.1039/c5cc07242e

We examine for the first time the ability of inert carbon free-radicals as soluble redox mediators to catalyze and enhance the oxygen reduction reaction in a (TEGDME)-based electrolyte. We demonstrate that the tris(2,4,6-trichlorophenyl)methyl (TTM) radical is capable of chemically favoring the oxygen reduction reaction improving significantly the Li-O 2 battery performance. Carbon free-radicals are used as soluble redox mediators to catalyze ORR and enhance the discharge of Li-O 2 batteries.