A novel three-dimensional cathode with stable long cycling performance for lithium oxygen batteries

Non-aqueous Li-O-2 battery has attracted plenty of interest due to its super theoretical energy density. Nevertheless, it also faces formidable challenges with respect to an unaccepted overpotential during charge process and a low round trip efficiency, which leads to a poor cycle life. Herein, we present a novel binder-free composite cathode comprised of MgCo2O4@3D graphene with a three-dimensional structure, which has never been used in the lithium oxygen batteries, as a cathode applied in the non-aqueous Li-O-2 battery. The MgCo2O4 nanowires as the catalyst is grown on the graphene substrate supported by the nickel foam. The discharge product Li2O2 formed with a flake-like morphology decompose at a low potential ascribed to excellent catalytic activity from MgCo2O4. Finally, we demonstrate a non-aqueous Li-O-2 battery capable of operating over 480 cycles with limiting capacity and rate values at 400 mAhg(-1) and 200 mAg(-1).