Novel sol-gel synthesis route of carbide-derived carbon composites for very high power density supercapacitors

Abstract

Sol-gel synthesis process was applied to obtain titanium carbide and titanium carbide/carbon nanotubes composites. These materials were used as precursors for the synthesis of carbide-derived carbon materials for supercapacitor electrodes. The results of X-ray diffraction, scanning electron microscopy and Raman spectroscopy showed that the synthesized CDC materials have average dimensions from 10 to 50µm and are dominantly amorphous with some relatively small graphitic crystallites inside particles. The low-temperature sorption experiments were performed and the specific DFT surface area up to 276m2g−1 for the synthesized carbides and up to 1710m2g−1 for carbon composites were obtained. Compared to traditional titanium carbide-derived carbons the materials exhibit larger specific DFT surface areas and a unique pore size distribution with more mesopores between 2 and 10nm.The energy-related properties of the supercapacitors based on the synthesized carbon materials in 1M (C2H5)3CH3NBF4 solution in acetonitrile were investigated using the cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge methods. The materials demonstrate nearly ideal capacitive behavior even at very high charging/discharging currents (10Ag−1) and potential scan rates (500mVs−1). The Ragone plots have been calculated from constant power tests, demonstrating high gravimetric energy densities (20Whkg−1) at high power densities (200kWkg−1).