The development of carbon nanotubes/RuO2•xH2O electrodes for electrochemical capacitors

Carbon nanotubes were refluxed with nitric acid to create acid sites on the surface. After such treatment, amorphous or nano-scale crystalline RuO2. xH(2)O can be adhered to the surfaces of carbon nanotubes by a simple method. RuO2. xH(2)O became more amorphous with decreasing the fraction of carbon nanotubes. The capacitance can be enhanced significantly by the adherence. When the weight fraction of RuO2. xH(2)O in the composite electrodes reached 75%, a specific capac- itance of 560 Fg(-1) was achieved. On the other hand, carbon nanotubes/RuO2. xH(2)O capacitors exhibit excellent power delivery behavior. So the processing of carbon nanotubes/RuO2. xH(2)O composite electrodes is a new attempt to fabricate supercapacitors with both high energy and high power density.