Preparation and Electrochemical Properties of Mesoporous Manganese Dioxide-Based Composite Electrode for Supercapacitor.

The mesoporous manganese dioxide with high specific surface area was obtained through a one-pot prepare procedure at ambient temperature under acidic conditions. And the graphene/mesoporous manganese dioxide composite was synthesized by a simple hydrothermal approach. As a comparison, silver nanowires also as a conductor was added to the mesoporous manganese dioxide. Both of the graphene and silver nanowires can increase the capacitance of the mesoporous manganese dioxide-based composite electrode materials. Compared with the graphene/mesoporous manganese dioxide composite, the silver nanowires/mesoporous manganese dioxide mixture has a better electrochemical performance, the specific capacitance and energy density is almost 2.2 times larger than that of the composites. The morphology and detail structure were investigated by the Scanning electron microscopy, X-ray diffraction, Raman spectra, Fourier transform infrared spectrometry and Nitrogen adsorption–desorption isotherms. The electrochemical performance was assessed by the cyclic voltammograms, galvanostatic charge/discharge and electrochemical impedance spectroscopy.