Dong Quanfeng

MnO/Nitrogen-doped graphene composite cathode for high performance lithium oxygen batteries

MnO/nitrogen-doped graphene (MnO/NG) composite cathode was fabricated by a facile one-pot method as cathode catalyst for non-aqueous lithium oxygen batteries. It exhibited superior electrochemical performance with higher round-trip efficiency and better cyclic stability. It showed a high round-trip efficiency of 84.6% at the current density of 0.05 mA cm−2 with the discharge and charge overpotentials of 0.11 and 0.41 V, respectively. Through scanning electron microscopy, transmission electron microscopy and X-ray photoelectron spectroscopy, it was confirmed that MnO nanoparticles were homogeneously dispersed on NG surface. The density functional theory calculations demonstrated that the superior electrochemical performance of MnO/NG might be attribute to the exposure of stoichiometric MnO (100) surface, with the ORR and OER overpotential only to be 0.21 and 0.24 V, respectively. The discharging-charging voltage gap is 0.45 V, in good agreement with the experimental value of 0.52 V.