Capacitive characteristics of binary manganese-nickel oxides prepared by anodic deposition

Because the rate of anodic deposition for manganese oxide is much larger than that for nickel oxide, the nickel content of binary Mn-Ni oxide can be increased by using a relatively positive potential region and a high Ni2+/Mn2+ ratio (10/1) in the deposition solution. The capacitive characteristics of this binary oxide in a mixed electrolyte consisting of 0.1 M Na2SO4 with pH 10.1 adjusted by 0.01 M NaOH are much more ideal than that measured in 0.1 M Na2SO4. The effects of introducing Ni oxide into the MnOx matrix on the capacitive performance are systematically investigated. The nanostructure of this Mn-Ni oxide deposit is demonstrated from the scanning electron microscopic morphology. (C) 2003 The Electrochemical Society.