Anodic deposition of hydrous ruthenium oxide for supercapacitors

摘要

This communication demonstrates the success in the anodic deposition of hydrous ruthenium oxide (denoted as RuO_2 centre dot xH_2O) from RuCl_3 centre dot xH_2O in aqueous media with/without adding acetate ions (CH_3COO~-, AcO~-) as the complex agent. The benefits of as-deposited RuO_2 centre dot xH_2O include the low electron-hopping resistance and the low contact resistance at the Ti-RuO_2 centre dot xH_2O interface which are clarified in electrochemical impedance spectroscopic (EIS) studies. The cycling stability, specific capacitance, and power performance of as-deposited RuO_2 centre dot xH_2O are further improved by annealing in air at 150 deg C for 2 h. The morphologies of as-deposited and annealed RuO_2 centre dot xH_2O films, examined by scanning electron microscopy (SEM), are very similar to that of thermally decomposed RuO_2. The high onset frequencies of 660 and 1650 Hz obtained from EIS spectra for the as-deposited and annealed RuO_2 centre dot xH_2O films, respectively, definitely illustrate the high-power merits of both oxide films prepared by means of the anodic deposition without considering the advantages of its simplicity, one-step, reliability, low cost, and versatility for electrode preparation.