Crystalline Ag nanocluster-incorporated RuO₂ as an electrode material for thin-film micropseudocapacitors

We prepared crystalline Ag nanocluster-incorporated RuO2 electrodes using a radio frequency magnetron cosputtering system for use in thin-film micropseudocapacitors and investigated their structural and electrochemical properties. High-resolution electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy results show that crystalline Ag nanoclusters are well dispersed within an amorphous RuO2. The Ag nanocluster-incorporated RuO2 electrodes show much higher capacitance of ∼1306.0 F/ cm3 at 200 mV /s with superb high-rate performance compared to RuO2 -only electrodes. The improved capacitance is explained in terms of the presence of dispersed Ag nanoclusters embedded within the amorphous RuO2 matrix having good electrical conductivity.