Hydrous–ruthenium–oxide thin film electrodes prepared by cathodic electrodeposition for supercapacitors

Hydrous ruthenium oxide (RuO2·nH2O) thin film electrodes were fabricated by cathodic electrodeposition on titanium substrates. The surface morphological characteristics of the RuO2·nH2O films were examined by scanning electron microscopy, and their images show the uniform spherical grains with nanometer sizes and porous network structure of the RuO2·nH2O films on Ti substrate. The electrochemical performances of the composite for supercapacitors were investigated by cyclic voltammetry, electrochemical impedance spectroscopy and charge/discharge technique. The RuO2·nH2O films exhibit good capacitive behavior, such as high reversible characteristics, excellent cycle stability, and superior power characteristics. The maximum specific capacitance of the RuO2·nH2O film electrode is 786 F g− 1 achieved with deposit mass of 0.17 mg.