Hydrous RuO2/carbon black nanocomposites with 3D porous structure by novel incipient wetness method for supercapacitors

For supercapacitor electrode material, hydrous RuO2/carbon black nanocomposites were prepared by the novel incipient wetness method using a fumed silica nanoparticle. First, hydrous RuO2/fumed silica/Ketjen black (KB) was synthesized by the sol-gel-based method. After dissolving the fumed silica, the hydrous RuO2/KB nanocomposite, which is composed of RuO2 nanoparticles (20 - 60 nm) dispersed on the high-surface-area KB (1180 m(2) g(-1)), was formed with 3D porous structure at high loading of 60 wt % RuO2 (Ru content is 46 wt %). The hydrous RuO2/KB nanocomposite electrode exhibited a specific capacitance of 647 F g(-1) with high charge utilization of RuO2 (72%), which is significantly higher than reported values by other workers at similar loading of RuO2. The high capacitance and the high charge utilization were probably due to enhanced proton paths within the 3D porous structure of the nanocomposite materials. (c) 2005 The Electrochemical Society. [DOI: 10.1149/1.2140677] All rights reserved.