Hollow Carbon Microspheres/MnO2 Nanosheets Composites: Hydrothermal Synthesis and Electrochemical Behaviors

Abstract

This article reported the electrochemical behaviors of a novel hollow carbon microspheres/manganese dioxide nanosheets (micro-HC/nano-MnO₂) composite prepared by an in situ self-limiting deposition method under hydrothermal condition. The results of scanning electron microscopy reveal that MnO₂ nanosheets homogeneously grow onto the surface of micro-HC to form a loose-packed microstructure. The quantity of MnO₂ required in the electrode layer has thereby been reduced significantly, and higher specific capacitances have been achieved. The micro-HC/nano-MnO₂ electrode presents a high capacitance of 239.0 F g^-1 at a current density of 5 mA cm^-2, which is a strong promise for high-rate electrochemical capacitive energy storage applications.