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

Abstract

Abstract In this study, NiCo 2 O 4 /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 NiCo 2 O 4 nanowire arrays without graphene oxide, it was found that the surface of NiCo 2 O 4 arrays grown directly on nickel foams had a large number of accumulations, whereas the surface agglomerations of NiCo 2 O 4 /rGO nanowire arrays complexed with reduced graphene oxide were significantly improved. The NiCo 2 O 4 /rGO electrode with improved agglomeration phenomenon shows better performance. The specific capacitance of NiCo 2 O 4 /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.