Facile fabrication of carbon-coated spinel nickel–cobalt–sulfide hollow spheres to achieve high-performance supercapacitors
Abstract
This paper presents a simple method to prepare carbon-coated spinel nickel–cobalt–sulfide metal hollow spheres with excellent electrochemical properties, which can be considered as promising materials for supercapacitors. A type of Ni–Co coordination polymer sphere is identified as a precursor metal template as well; the prepared coordination polymer precursor sphere is vulcanized to obtain the NiCo2S4 hollow metal sphere. After that, glucose modified on the surface of the hollow metal sphere is the source of carbon. After hydrothermal sulfuration treatment the carbon-coated NiCo2S4 hybrid material is obtained, which is sintered in a tube furnace to improve the crystallinity of the materials. The compound materials reveal advanced specific capacitance (1367 F g−1 at 1 A g−1) and advantageous cycling stability (approximately 89.2% maintained after 6000 cycles at 10 A g−1).