MnCo2O4 Nanowires Anchored on Reduced Graphene Oxide Sheets as Effective Bifunctional Catalysts for Li-O2 Battery Cathodes

A hybrid composite system of MnCo2O4 nanowires (MCO NWs) anchored on reduced graphene oxide (RGO) nanosheets was prepared as the bifunctional catalyst of a Li-O-2 battery cathode. The catalysts can be obtained from the hybridization of one-dimensional MCO NWs and two-dimensional RGO nanosheets. As O-2-cathode catalysts for Li-O-2 cells, the MCO@RGO composites showed a high initial discharge capacity (ca. 11092.1 mAhgcarbon(-1)) with a high rate performance. The Li-O-2 cells could run for more than 35 cycles with high reversibility under a limited specific capacity of 1000 mAhgcarbon(-1) with a low potential polarization of 1.36 V, as compared with those of pure Ketjenblack and MCO NWs. The high cycling stability, low potential polarization, and rate capability suggest that the MCO@ RGO composites prepared here are promising catalyst candidates for highly reversible Li-O-2 battery cathodes.