Carbon nanotube capacitor materials loaded with different amounts of ruthenium oxide

Ruthenium oxide-carbon nanotubes composites with different loadings of RuO2 on carbon nanotubes have been synthesized. In order to design nanotube-based ruthenium oxide coated supercapacitor electrodes with large surface area, a new sol-gel process for the preparation of ultrafine RuO2 particles was developed. The composite electrodes consisting of carbon nanotube and RuO2 . xH(2)O were developed by the deposition of RuO2 on the surface of carbon nanotube. Maximum capacitance was observed after heat treatment at 250degreesC for all the composites. Supercapacitors based on the composite electrodes show much higher specific capacitance than those based on pure carbon nanotube ones. A specific capacitance of 570 F . g(-1) can be achieved when the weight percent, of RuO2 . xH(2)O in the composite electrodes reaches 100%. In addition, supercapacitors based on the composite electrodes show both high energy density and high power density characteristics.