One-step Electrophoretic Deposition of Ni-Decorated Activated-Carbon Film as an Electrode Material for Supercapacitors

Ni-decorated activated-carbon film is deposited directly onto the stainless steel substrate by using electrophoretic deposition (EPD) in the activated-carbon suspension containing nickel nitrate additive. The adsorption of nickel ions on the external surface and interior pores of activated carbons considerably increases the measured zeta potential and consequently favors the dispersion and EPD of activated carbons. More importantly, when an activated carbon arrives at the substrate in the EPD process, nickel ions adsorbed on the activated carbon are reduced electrochemically to a form metallic nickel layer. The deposited nickel layer plays an important role in improving the adhesion, wettability, and electrochemical reaction of the Ni-decorated activated-carbon film. Therefore, the Ni-decorated activated-carbon film exhibits an excellent capacitive behavior compared with the bare activated-carbon film.