High performance supercapacitors using metal oxide anchored graphene nanosheet electrodes

Metal oxide nanoparticles were chemically anchored onto graphene nanosheets (GNs) and the resultant composites-SnO(2)/GNs, MnO(2)/GNs and RuO(2)/GNs (58% of GNs loading)-coated over conductive carbon fabric substrates were successfully used as supercapacitor electrodes. The results showed that the incorporation of metal oxide nanoparticles improved the capacitive performance of GNs due to a combination of the effect of spacers and redox reactions. The specific capacitance values (with respect to the composite mass) obtained for SnO(2)/GNs (195 F g(-1)) and RuO(2)/GNs (365 F g(-1)) composites at a scan rate of 20 mV s(-1) in the present study are the best ones reported to date for a two electrode configuration. The resultant supercapacitors also exhibited high values for maximum energy (27.6, 33.1 and 50.6 W h kg(-1)) and power densities (15.9, 20.4 and 31.2 kW kg(-1)) for SnO(2)/GNs, MnO(2)/GNs and RuO(2)/GNs respectively. These findings demonstrate the importance and great potential of metal oxide/GNs based composite coated carbon fabric in the development of high-performance energy-storage systems.