Electrical and microstructural investigations of cermet anode/YSZ thin film systems

We describe the preparation, electrochemical and structural properties of the thin film Y-stabilized ZrO2 (YSZ), of interest for solid oxide fuel cell (SOFC) at an operating temperature of 800°C. Thin films of YSZ were prepared by reactive sputtering deposition of Zr–Y targets in Ar–O2 mixture atmospheres. The thickness of the YSZ film, deposited onto the porous NiO–YSZ substrates, is approximately 8 μm. The microstructure of the YSZ film was investigated using scanning electron microscope. The electrochemical properties of a thin film cell Ag/NiO–YSZ/YSZ/Ag were studied using impedance spectroscopy. The electrolyte and electrode (substrate) resistances were measured under different atmospheres as a function of temperature. Above 600°C the ohmic resistance of the cermet electrode (substrate) is comparable to the ionic resistance of the solid electrolyte. This is probably influenced by the cermet electrode microstructure.