Ab initio study of the charge storage mechanism of ruthenium dioxide as an electrochemical ultracapacitor

The charge storage mechanisms of ruthenium dioxide were investigated by first principles calculations. Both H-injected bulk and H-adsorbed RuO2(110) surface have been studied in order to obtain a whole picture of the discharging process of ruthenium dioxide as a supercapacitor. We have predicted the crystal structure of ruthenium-oxy-hydroxide (ROOH). By ab-inito voltage calculations, we also found that the RuO2(110) surface is completely hydrated before the usual voltammagram measurements, which suggests that the redox reactions happen in deep layers and should be diffusion dominated processes.