Synthesis of the 3D porous carbon-manganese oxide (3D-C@MnO) nanocomposite and its supercapacitor behavior study

A 3D porous carbon-manganese oxide (3D-C@MnO) nanocomposite is successfully synthesized via a thermal plasma deposition method. The chemical bonds and compositions, phase structures, surface morphologies, etc. of as-obtained 3D-C@MnO nanocomposite were characterized by the various equipment, such as X-ray diffractometer, X-ray photoelectron spectroscopy, and electron microscopes. The electrochemical performances of the 3D-C@MnO nanocomposite electrode showed a specific capacitance of 780 F g−1 at a current density of 2 A g−1 and a capacitance retention rate of 99% after 5000 charge-discharge cycles at a high current density of 10 A g−1. These excellent capacitive performances may be attributed to the encapsulation of MnO nanoparticles by porous carbon sheets in the 3D-C@ MnO nanocomposite structure. It is believed that the carbon-encapsulated MnO nanoparticles can be protected from a volume deformation during the charge adsorption/desorption cycle and can be electrically improved by the encapsulated carbon sheets, resulting in better overall capacitive performance. In addition, this study also demonstrates the practical applicability by assembling a supercapacitor using the as-obtained 3D-C@MnO nanocomposite to glow a light emitting diode. Keywords: Nanocomposites, 3D-carbon, Manganese monoxide, Cathode material, Supercapacitor