Novel Synthesis of 3D Graphene-CNF Electrode Architectures for Supercapacitor Applications.

摘要

This manuscript presents a novel synthetic pathway for the generation of three-dimensional architectures which main structural component includes the combination of Graphene (G) and Carbon Nanofibers (CNF). The Reduction Expansion Synthesis (RES) approach was used for both, the exfoliation of Graphitic Oxide to produce Graphene, and the simultaneous reduction of a nickel salt to generate Ni catalyst. Carbon Nanofibers were grown from Ni following procedures previously reported. The use of dry and wet conditions for the RES synthesis was explored and the variability of sample properties due to such change analyzed. Resulting composites, Graphene/Carbon Nanofibers/Nickel nanoparticles (G/CNF/Ni) were characterized by X-ray diffraction, Scanning Electron Microscopy and BET surface area analysis. Some specimens were oxidized to produce G/CNF/NiO. All the materials were then used as electrodes in supercapacitor cells and the capacitance of the same evaluated. The growth of carbon nanofibers within the Graphene layers prevented the collapse of the layers when the material was laid as a paste in the current collectors and increased both ion and charge transport between the Graphene sheets. When combined with pseudocapacitive effects of NiO, a 350 percent increase in specific capacitance was attained for the G/CNF/NiO material when compared with its individual components.