Porous-sheet-assembled Ni(OH)2/NiS arrays with vertical in-plane edge structure for supercapacitor with high stability
Hierarchical arrays of transition metal compounds directly grown on a current collector to fabricate the binder-free electrode are a promising strategy to achieve high-performance hybrid supercapacitors owing to its high surface area and low inner resistance. To engineer the microstructure of the hierarchical structure can further efficiently improve capacitive performance. In this work, a hierarchically structured Ni(OH)2/NiS nano-sheet arrays, with the vertical growth of secondary nanosheets on their surface, are directly fabricated onto carbon cloth via an NH4F-induced method. Due to adequate exposed-edge planes available on the surface, the Ni(OH)2/NiS exhibits remarkable electrocapacitive properties with a high specific capacity of 668 μAh cm-2 at 2 mA cm-2 in 3 M KOH medium, as well as excellent cycling performance (97% capacitance retention after 10000 cycles). Besides, the Ni(OH)2/NiS electrode also delivers excellent performance as the flexible and lightweight electrode in a solid-state flexible supercapacitor.