Synergistic interaction between pseudocapacitive FeO nanoparticles and highly porous silicon carbide for high-performance electrodes as electrochemical supercapacitors.

Composites of micro- and mesoporous SiC flakes (SiCF) and ferroferric oxide (FeO), SiCF/FeO, were prepared via the chemical deposition of FeO on SiCF by the chemical reduction of an Fe precursor. The SiCF/FeO electrodes were fabricated at different FeO feeding ratios to determine the optimal FeO content that can maintain a high total surface area of SiCF/FeO composites as well as cause a vigorous redox reaction, thereby maximizing the synergistic effect between the electric double-layer capacitive effects of SiCF and the pseudo-capacitive effects of FeO. The SiCF/FeO electrode fabricated with a FeO/SiCF feeding ratio of 1.5:1 (SiCF/FeO(1.5)) exhibited the highest charge storage capacity, showing a specific capacitance of 423.2 F g at a scan rate of 5 mV s with a rate performance of 81.8% from 5 to 500 mV s in an aqueous 1 M KOH electrolyte. The outstanding capacitive performance of the SiCF/FeO(1.5) electrode could be attributed to the harmonious synergistic effect between the electric double-layer capacitive contribution of the SiCF and the pseudocapacitive contribution of the FeO nanoparticles introduced on the SiCF surface. These encouraging results demonstrate that the SiCF/FeO(1.5) electrode is a promising high-performance electrode material for use in supercapacitors.