Mesoporous carbon materials as electrodes for electrochemical supercapacitors

In this paper, we report the synthesis and characterization of mesoporous carbons, which were obtained using SBA-15 silica as the template material and sucrose as the carbon source. The prepared silica template and mesoporous carbons were characterized by nitrogen adsorption-desorption, low angle X-ray diffraction (XRD) and transmission electron microscopy (TEM). Synthesized carbons were used to prepare composite electrodes for solid-state supercapacitors. The electrochemical characteristics of mesoporous carbons in supercapacitors were studied by cyclic voltammetry and electrochemical impedance spectroscopy. The study showed that a value of specific capacitance of 132 F g-1 (for a single electrode) was obtained with the CMK-3A mesoporous carbon, which was 68% higher than that of an activated carbon that was used as a reference material. The superior performance was 127% (12.05 ?F cm-2 vs. 5.3 ?F cm-2) when the double-layer capacitance of the mesoporous carbon was compared to that of the reference carbon. These findings for the mesoporous carbon-based supercapacitor were explained on the basis of a high pseudo-capacitance and other physico-chemical properties of this carbon, such as the pore structure, accessibility of pores to the electrolyte, and surface wettability by surface functional groups. All of these properties were improved compared to those of the activated carbon.