Electrochemical, topographical, and morphological properties of thermally-prepared Ir-x-Ru1-x-oxide coatings of various compositions (0 < x 1), formed on a Ti metal substrate, were investigated for their potential application as supercapacitor (SC) electrodes employing scanning electron microscopy and electrochemical techniques of cyclic voltammetry, galvanostatic charge/discharge cycling, and electrochemical impedance spectroscopy. A current state-of-the-art pure ruthenium oxide (RuO2) coating showed relatively low performance compared to other bimetallic IrxRu1-x-oxide coatings operated under the same experimental conditions. An electrochemically-activated Ir0.4Ru0.6-oxide coating yielded the highest capacitance value (85 mF cm(-2)). Prolonged electrochemical cycling of the Ir/Ru-oxide coatings in a corrosive phosphate-buffered saline pH=7.4, performed within an extreme potential window of 5V, revealed an excellent stability of the coatings. In addition, this cycling procedure enabled a significant increase in capacitance for all coating compositions. It was shown that the areal capacitance (C-GA) of these coatings is strongly dependent upon the nature of the components of which the metal oxide is composed. The addition of IrO2 to RuO2 improved the stability and capacitive performance of the thermally-prepared Ir-Ru-oxide coatings.