Au-coated carbon cathodes for improved oxygen reduction and evolution kinetics in aprotic Li-O2 batteries

Metal-oxygen systems are an attractive option to enhance the specific energy of secondary batteries. However, their power is limited by the oxygen electrode. In this communication we address the issue of the sluggish kinetics of the oxygen cathode in the aprotic Li-O2 batteries. The electrochemical performances of newly designed carbon electrodes coated with 50 Å thick Au layer are evaluated and compared with those of unmodified electrodes. Despite the low noble metal content (~ 2 wt.%), the Li-O2 batteries built with the abovementioned Au-coated cathodes show considerably enhanced kinetics as demonstrated by the higher onset potentials for the oxygen reduction reaction (~ 2.6 V at a current rate of 1000 mA g− 1), together with reduced oxygen evolution potentials.