Author/Authors :
Deng, Ming-Jay National Cheng Kung University - Department of Chemistry, Taiwan , Huang, Fu-Lu National Cheng Kung University - Department of Chemistry, Taiwan , Sun, I-Wen National Cheng Kung University - Department of Chemistry, Taiwan , Tsai, Wen-Ta National Cheng Kung University - Department of Materials Science and Engineering, Taiwan , Chang, Jeng-Kuei National Cheng Kung University - Department of Materials Science and Engineering, Taiwan
Abstract :
A nano-structured Co oxide electrode (with a Ni substrate) was successfully prepared using an entirely electrochemical process, which included the co-deposition of a Ni–Cu alloy film, selective etching of Cu from the film, and anodic deposition of Co oxide on the obtained nano-porous Ni substrate which had an average pore size of approximately 100 nm and a pore density of about 1013 m−2. The excellent electrochemical activity of the prepared electrode was demonstrated in terms of its pseudocapacitive performance, which was evaluated using cyclic voltammetry (CV) in 1 M KOH solution. The specific capacitance of the nano-structured Co oxide measured at a potential scan rate of 10 mV s−1 was as high as 2200 F g−1, which is over ten times higher than that of a flat oxide electrode (209 F g−1). The highly porous Co oxide also had superior kinetic performance as compared to a flat electrode. At a high CV scan rate of 50 mV s−1, the two electrodes retained 94% and 59%, respectively, of their specific capacitances measured at 5 mV s−1.
