Preparation of NiCo2S4 flaky arrays on Ni foam as binder-free supercapacitor electrode

Abstract NiCo 2 S 4 flaky structured arrays on nickel foam were prepared hydrothermally by means of an anion-exchange method, with NiCo 2 O 4 nanorod arrays as precursors, and were directly applied as a binder-free supercapacitor electrode. Such a 3D structured electrode combines the advantages of both one dimensional and two dimensional materials, and can effectively improve the electrochemical performance. As a result, the as-prepared NiCo 2 S 4 flaky structure electrode shows much enhanced electrochemical performance, with a high specific capacitance (2044 F g −1 at 1 A g −1 ) and good cycling stability (capacity retention of 77% after 2000 cycles), suggesting its promising application for electrochemical capacitors.