Fabrication of Thin-Film, Flexible, and Transparent Electrodes Composed of Ruthenic Acid Nanosheets by Electrophoretic Deposition and Application to Electrochemical Capacitors

Abstract

Ruthenic acid nanosheet colloids were prepared by dispersing a tetrabutylammonium–ruthenic acid intercalation compound in acetonitrile or N,NN,N -dimethylformamide. Nanosheet electrodes were fabricated on gold, indium-tin oxide (ITO)-coated glass, and ITO-coated poly(ethylene terephthalate) (PET) electrodes by electrophoretic deposition using these colloids. Transparent or flexible electrodes could be fabricated by using ITO electrodes as the substrate. The deposited amount of material could easily be controlled by the extent of deposition, which was confirmed from the linear increase in specific capacitance as a function of deposition time. The ruthenic acid nanosheet electrodes using Au substrates exhibited gravimetric capacitance of 620F620F (g-RuO2)−1(g-RuO2)−1 . Specific capacitance of 0.82Fcm(geometric)−20.82Fcm(geometric)−2 was achieved at a scan rate of 2mVs−12mVs−1 with a film deposited at 5Vcm−15Vcm−1 for 1h1h .