MnO-encapsulated graphene cubes derived from homogeneous MnCO3-C cubes as high performance anode material for Li ion batteries

Abstract

Nanocomposites containing high capacity anode materials (such as Si, Sn or transition metal oxides) and carbon matrix, are widely studied to obtain high performance anodes for Li ion batteries (LIBs). However, these nanocomposites often suffer from low structural stability and high irreversible Li storage. Here, MnO-encapsulated graphene cubes are produced by calcination of homogeneous MnCO3-C composite cubes. The cubic graphene shells provide high conductivity and excellent structural stability to the MnO cores, and the high calcination temperature of 1200 °C can significantly reduce the specific surface area of the MnO@graphene cubes and thus reduce their irreversible capacity. The MnO@graphene cubes exhibit high Li storage capacity (1092 mAh g−1 at 50 mA g−1 and 790 mAh g−1 at 500 mA g−1) at a voltage platform ∼ 1 V, superior rate capability (586 mAh g−1 at 1000 mA g−1) and excellent long term cycling performance (undiminished after 500 cycles). Our results provide a useful method to design high performance graphene-based anode composites for LIBs.