Deposition of Ni–CGO composite anodes by electrostatic assisted ultrasonic spray pyrolysis method

Deposition of composite films of Ni and Gd-doped ceria was carried out using the electrostatic assisted ultrasonic spray pyrolysis method for the first time. The composite films were highly homogeneous, as revealed by element mapping via energy-dispersive spectrometry. Scanning electron microscope examinations revealed that deposition temperature and electric field strength had profound influence on resultant microstructure, while composition of the precursor solution had little effect. A highly porous cauliflower structure ideal for solid oxide fuel cell anode performance was obtained with a deposition temperature of 450 °C under an electric field introduced by an applied voltage of 12 kV. Films obtained with a lower deposition temperature of 250 °C or a higher applied voltage of 15 kV resulted in denser films with low porosity, while lower applied voltages of 7 or 5 kV resulted in thinner or discontinuous films due to the insufficient electrostatic attraction on the aerosol droplets. As revealed by AC impedance measurement, the area specific resistances of the Ni–CGO anode with porous cauliflower structure were rather low and a value of 0.09 Ω cm2 at 550 °C was obtained.