Interconnected NiS nanosheets supported by nickel foam: Soaking fabrication and supercapacitors application

In this article, interconnected and staggered nickel sulfide nanosheets grown on nickel foam have been successfully prepared by an ultrasound-assisted soaking method using nickel hydroxide nanosheets as precursor. As electrode material for supercapacitor, the nickel sulfide nanosheets are characterized by cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS) measurements. Owing to the unique structure, the nickel sulfide nanosheets exhibit excellent electrochemical performance, including high area capacitances (2.64 F cm(-2)) and remarkable cycling stability (90% retaining after 2000 cycling). Therefore, such a novel and facile synthetic route to synthesis the high-performance nickel sulfide nanosheets may open a new pathway to prepare sulfide materials with distinctive nanostructures and outstanding electrochemical performance. At the same time, asymmetric supercapacitor is fabricated with NiS-NF as positive material and active carbon as negative material. The asymmetric supercapacitor shows excellent long-term electrochemical stability and high energy density. All these results illustrate that the NiS-NF electrode is promising for potential application in supercapacitors and other fields. (C) 2014 Elsevier B.V. All rights reserved.