MgO-decorated few-layered graphene as an anode for Li-ion batteries

Abstract

Combustion of magnesium in dry ice and a simple subsequent acid treatment step resulted in a MgO-decorated few-layered graphene (FLG) composite that has a specific surface area of 393 m2/g and an average pore volume of 0.9 cm3/g. As an anode material in Li-ion batteries, the composite exhibited high reversible capacity and excellent cyclic performance in spite of high first-cycle irreversible capacity loss. A reversible capacity as high as 1052 mAh/g was measured during the first cycle. Even at the end of the 60th cycle, more than 83% of the capacity could be retained. Cyclic voltammetry results indicated pseudocapacitance behavior due to electrochemical absorption and desorption of lithium ions onto graphene. An increase in the capacity has been observed during long-term cycling owing to electrochemical exfoliation of graphene sheets. Owing to its good thermal stability and superior cyclic performance with high reversible capacities, MgO-decked FLG can be an excellent alternative to graphite as an anode material in Li-ion batteries, after suitable modifications.