Effects of microstructure and electrochemical properties of Ti/IrO2–SnO2–Ta2O5 as anodes on binder-free asymmetric supercapacitors with Ti/RuO2–NiO as cathodes

Abstract Ti/IrO2–SnO2–Ta2O5 was prepared by thermal decomposition. The phase structure, surface morphology and capacitive properties of the electrodes annealed at different temperatures were analyzed in detail. The electrodes annealed at 370 °C had the largest area of the cyclic voltammogram, the smallest Zim, the minimum relaxation time, and the largest specific capacitance of 382.9 F/g, which was lager than those of IrO2–SnO2 and IrO2–Ta2O5. The conductive nanocrystalline particles was homogeneously distributed in the amorphous matrix, which could greatly improve the conductivity of electrons in coatings, but it did not sacrifice the conductivity of protons. Ti/IrO2–SnO2–Ta2O5 electrodes prepared at 370 °C and Ti/RuO2–NiO electrode prepared in the same way were assembled to be a supercapacitor, which provided energy density of 12.8wh kg−1 and 1.86wh kg−1 respectively and the power density of 29w kg−1 and 252.7w kg−1. The energy density and power density in acidic solution could be detected without using binder materials. The prepared method was simple, economical and did not require binder which provided a possibility for the large-scale industrial production of pseudocapacitor.