Co(OH) 2/SBA-15 molecular sieves nanocomposite materials for electrochemical capacitors

Abstract

A nano-flake network cobalt hydroxide and well-ordered hexagonal mesoporous silica SBA-15 molecular sieves nanocomposite materials (designated as Co(OH) 2/SBA-15) for electrochemical capacitor electrode have been prepared using a liquid-precipitated method. The electrochemical capacitance characterization of the Co(OH) 2/SBA-15 materials was performed using cyclic voltammetry, chronopotentiometry, and impedance spectroscopy, respectively. These nano-flakes cobalt hydroxide maintain high utilization at high rates of discharge. A maximum specific capacitance of 467.5 F g −1 can be achieved in 2 M aqueous KOH with the potential range from −0.2 to 0.4 V (vs. SCE) in a three-electrode glass cell at room temperature for the Co(OH) 2/SBA-15 electrode, suggesting its potential application in electrochemical capacitors. Furthermore, the effect of annealing temperatures on the electrochemical capacitance characteristics has also been explored.