MnO/reduced graphene oxide sheet hybrid as an anode for Li-ion batteries with enhanced lithium storage performance

Relatively small hysteresis in voltage, appropriate electromotive force and low average delithiation voltage make MnO, among many transition metal oxides. MnO/reduced graphene oxide sheet (MnO/RGOS) hybrid is synthesized by a two-step electrode design consisting of liquid phase deposition of MnCO3 nanoparticles on the surface of graphene oxide sheets followed by heat treatment in flowing nitrogen. As an anode for Li-ion batteries, the MnO/RGOS hybrid electrode shows a reversible capacity of 665.5 mA h g(-1) after 50 cycles at a current density of 100 mA g(-1) and delivers 454.2 mA h g(-1) at a rate of 400 mA g(-1), which is obviously better than that of bare MnO electrode. Those reasons for such enhanced electrochemical properties are investigated by galvanostatic intermittent titration technique (GITT) as well as electrochemical impedance spectroscopy (EIS). The probable origins, in the term of thermodynamic and kinetic factors, for the marked hysteresis in voltage observed between charge and discharge are also discussed. (C) 2012 Elsevier BM. All rights reserved.