Optimized NiCo2O4/rGO hybrid nanostructures on carbon fiber as an electrode for asymmetric supercapacitors

The NiCo2O4 nanowires and reduced graphene oxide (rGO) hybrid nanostructure has been constructed on carbon fibers (NiCo2O4/rGO/CF) via a hydrothermal method. The effects of graphene oxide (GO) concentration on the structure and performance of the NiCo2O4/rGO/CF were investigated in detail to obtain the optimized electrode. When the GO concentration was 0.4 mg ml(-1), the rGO/NiCo2O4/CF composite exhibited a maximum specific capacitance of 931.7 F g(-1) at 1 A g(-1), while that of NiCo2O4/CF was 704.9 F g(-1). Furthermore, the NiCo2O4/rGO/CF//AC asymmetric supercapacitor with a maximum specific capacitance of 61.2 F g(-1) at 1 A g(-1) was fabricated, which delivered a maximum energy density (24.6 W h kg(-1)) and a maximum power density (8477.7 W kg(-1)). Results suggested that the NiCo2O4/rGO/CF composite would be a desirable electrode for flexible supercapacitors.