Facile synthesis of NiCo2 O4/rGO nanowire array electrodes for supercapacitor cathodes

Abstract

In this study, NiCo2O4/rGO nanowire arrays (NWAs) were effectively synthesized, and these arrays were subsequently employed as components in supercapacitors. The phase structure of the materials was analyzed using X-ray diffraction spectroscopy, and the morphology of the materials was observed by scanning and transmission electron microscopy. By comparing with NiCo2O4 nanowire arrays without graphene oxide, it was found that the surface of NiCo2O4 arrays grown directly on nickel foams had a large number of accumulations, whereas the surface agglomerations of NiCo2O4/rGO nanowire arrays complexed with reduced graphene oxide were significantly improved. The NiCo2O4/rGO electrode with improved agglomeration phenomenon shows better performance. The specific capacitance of NiCo2O4/rGO NWAs is 2311 F·g-1 at 1 A·g-1 and remains at 1211 F·g-1 even at 50 A·g-1. In addition, the capacitance retention of this material could reach 83.5 % after 3,000 cycles at 10 A·g-1, demonstrating excellent multiplicative performance and cycling stability.