A facile approach to the preparation of loose-packed Ni(OH)2 nanoflake materials for electrochemical capacitors

Loose-packed nickel hydroxides were successfully synthesized by a facile chemical precipitation method. Structure characterizations indicate that a nanoflake structure with low crystallinity for the nickel hydroxide samples was obtained. Electrochemical studies were carried out using cyclic voltammetry, chronopotentiometry technology, and alternating current impedance spectroscopy, respectively. A maximum specific capacitance of 2,055F/g could be achieved in 2M aqueous KOH with the potential range of 0 to 0.4V (vs. the saturated calomel electrode) in a half-cell setup configuration for the nanoflake Ni(OH)(2) electrode, suggesting its potential application in the electrode material for electrochemical capacitors. Furthermore, the effect of annealing temperatures on the electrochemical capacitance characteristics has also been systemically explored.