Hierarchical nanospheres of NiCoS/NF for high-performance supercapacitors

Abstract

Transition metal sulfides are promising electrode materials due to the better conductivity and higher electrochemical activity compared to transition metal oxides. NiS and NiCoS was synthesized using a simple hydrothermal deposition method for high-performance supercapacitor (SC) applications. The resulting NiS and NiCoS electrodes were characterized by X-ray diffraction, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The electrochemical performance of the prepared electrodes was examined by cyclic voltammetry, galvanostatic charge–discharge, and electrochemical impedance spectroscopy. The NiCoS/NF delivered a high specific capacitance of 922.06 F g−1 at a current density of 0.62 A g−1 and outstanding capacitance retention of 92.1% after 3000 cycles at 2.5 A g−1. The superior specific capacitance and cycling performance of the NiCoS/NF composite can be attributed to rapid transfer path for electrons and ions, large surface area, and suitable surface morphology, highlighting its potential applications in SCs.