SnO2–RuO2 composite films by chemical deposition for supercapacitor application

A chemical bath deposition method is used for preparing SnO2–RuO2 composite films. The films with varying RuO2 composition are prepared by varying the vol% of RuCl3 in the bath and their structural, morphological and supercapacitive properties are studied. The structural study revealed that the composite films are amorphous. FT-Raman spectrum showed the fundamental vibrations of SnO2 and RuO2, confirming the formation of SnO2–RuO2 composite. The elongated particle structures are observed from morphological studies. The supercapacitive studies showed highest specific capacitance of 150 F g−1 for SnO2–RuO2 composite containing 15 vol% of RuCl3 in the deposition bath. The charge–discharge curves showed the pseudocapacitive performance with maximum energy density of 4.9 Wh kg−1 at a power density of 0.42 kW kg−1 for optimized SnO2–RuO2 composite. An equivalent series resistance (ESR) of 12 Ω is observed from the electrochemical impedance studies.