Oxidative Synthesis of RuO[sub x]⋅nH[sub 2]O with Ideal Capacitive Characteristics for Supercapacitors

A simple method with a high product yield (about 99%), i.e. , chemical oxidation of with is successfully developed for the synthesis of hydrous ruthenium oxide (denoted as The main product of this chemical synthesis is with a significant amount of from the X-ray photoelectron spectroscopy results. All powders without and with annealing in air between 150 and 400°C for 2 h show an amorphous structure from the X-ray diffraction and electron diffraction analysis. The annealed with the amorphous structure exhibits the ideal capacitive performance ( i.e. , highly electrochemical reversibility, high-power property, and excellent stability). The specific capacitance of annealed measured at 25 mV/s from a -coated graphite electrode (denoted as is ⩾500 F/g when the annealing temperature is between 200 and 350°C. © 2004 The Electrochemical Society. All rights reserved.