Synthesis and electrochemical properties of graphene/MnO2 composites

Abstract

Accordion-like MnO2-coated graphene composites were successfully prepared by a facile hydrothermal method at 160℃. The as-products were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray dif-fraction, energy dispersive spectrometry, BET and Raman spectroscopy. The high capacitance of 138 F·g-1 at 0.2 A·g-1 is achieved with MnO2/graphene composites as a supercapacitor electrode, much higher than that of a single MnO2 or graphene electrode. The ex-cellent electrochemical performance is attributed to the uniform MnO2 nanosheet morphology, large surface area of graphene and stable chemical bonding of MnO2 on the graphene substrate.