Electrochemical performance of nickel hydroxide nanopetals for supercapacitor electrodes

Nickel hydroxide and nickel oxide were prepared via a facile chemical precipitation method, whose structure, morphology and electrochemical properties were compared. Nickel hydroxide demonstrated nanopetal-like morphology, pseudocapacitive nature, a superior specific capacitance of 701 F g(-1) at 1 Ag-1 and admirable capacitance retention of 84.16% even after 5000 consecutive charge-discharge cycles in 2 M KOH aqueous electrolyte. Meanwhile, nickel oxide grew into a cluster of randomly shaped nanostructures with pseudocapacitive behavior and comparatively lower specific capacitance of 171 F g(-1) at 1 A g(-1). In nickel hydroxide, the freedom of movement of electrolyte ions is responsible for its loftier charge storage capability. (C) 2018 Elsevier B.V. All rights reserved.