Direct Characterization by a Porous-Microelectrode of Powder Materials for Electrochemical Capacitors-Hydrous Ruthenium Oxide as a Benchmark

Abstract

Powders of RuO_2•0.5H₂O have been successfully characterized for their electrochemical capacitive performance using a microporous electrode (PME) that does not require the use of binder. The cavity at the tip of the PME was filled with less than 100 ng of RuO_2•0.5H₂O powder. Cyclic voltammetry; constant current charge-discharge, and electrochemical impedance spectroscopy were carried out in 0.5 M H₂SO₄ aqueous solution. Capacitances as high as 950 F g^-1 are reported for the first time concerning this material. These values are more than 25% larger than these previously reported in the literature for RuO_2•0.5H₂O characterized by means of composite electrodes.