Preparation and Electrochemical Properties of Polyaniline Composite Electrodes Prepared by In-Situ Polymerization in Hydrous Ruthenium Oxide Dispersed Aqueous Solution.

Polyaniline (PANI)/ruthenium oxide (RuO2) composites were prepared by a chemical oxidation polymerization with various amount of hydrous RuO2. In the PANI/RuO2 composites, RuO2 particles were surrounded by PANI. The morphology and structure of the PANI/RuO2 composites were examined by field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Analysis by TEM revealed that the aggregations of the composites were increased with the amounts of hydrous RuO2. Electrochemical performances of prepared composites were characterized by cyclic voltammetry (CV). The composites prepared with 20 wt% of hydrous RuO2 per aniline monomer showed the highest specific capacitance of 710 F/g at 5 mV/s among the prepared composites. However, the specific capacitance of the composites with excess amounts of hydrous RuO2 is lower than the highest one. The large aggregation of RuO2 particles prevents the participation in electrochemical reaction due to the long pathway from the electrolyte and a decrease of effective surface area.