Anodic composite deposition of RuO2 reduced graphene oxide carbon nanotube for advanced supercapacitors

Anodic composite deposition is demonstrated to be a unique method for fabricating a ternary ruthenium dioxide reduced graphene oxide carbon nanotube (RuO2 xH2O rGO CNT, denoted as RGC) nanocomposite onto Ti as an advanced electrode material for supercapacitors. The rGO CNT composite in RGCs acts as a conductive backbone to facilitate the electron transport between current collector and RuO2 xH2O nanoparticles (NPs), revealed by the high total specific capacitance (CS,T = 808 F g−1) of RGC without annealing. The contact resistance among RuO2 xH2O NPs is improved by low-temperature annealing at 150 °C (RGC-150), which renders slight sintering and enhances the specific capacitance of RuO2 xH2O to achieve 1200 F g−1. The desirable nanocomposite microstructure of RGC-150 builds up the smooth pathways of both protons and electrons to access the active oxy-ruthenium species. This nanocomposite exhibits an extremely high CS,T of 973 F g−1 at 25 mV s−1 (much higher than 435 F g−1 of an annealed RuO2 xH2O deposit) and good capacitance retention (60.5% with scan rate varying from 5 to 500 mV s−1), revealing an advanced electrode material for high-performance supercapacitors.