Journal of Materials Science, Vol.50, No.19, 6491-6497, 2015
Electrochemical preparation and energy storage properties of nanoporous Co(OH)(2) via pulse current deposition
Nanoporous Co(OH)(2) films are electrochemically deposited on Ni foams by pulse current deposition for supercapacitor application. The pore size and density are controlled by reaction conditions including frequency modulation and reaction time. The morphology of the films is monitored by SEM, and the chemical composition and crystal structure are confirmed by XPS and XRD, respectively. The electrochemical performance of the Co(OH)(2) film is characterized by cyclic voltammetry and charge-discharge tests. The charge-transfer resistances of the electrodes are examined by electrochemical impedance spectroscopy. The Co(OH)(2) film exhibits an excellent specific capacity of 1681 F g(-1) at a current density of 2 A g(-1) in a potential range of -0.1 to 0.4 V from the charge/discharge test; this specific capacity is much higher than that obtained by direct current deposition (623 F g(-1) at the same condition) due to the highly porous structure.