Nanostructured zirconia thin film fabricated by electrophoretic deposition technique

Abstract

A simple strategy based on electrophoretic deposition (EPD) technique is presented to fabricate nanostructured 8 mol% yttria stabilized zirconia (YSZ) thin film onto NiO-YSZ anode substrate. As a prerequisite for EPD technique, stable suspension of YSZ nanoparticles has been prepared in isopropanol medium using phosphate ester (PE) as dispersant. Effect of PE concentration on zeta potential, pH, electrical conductivity and stability of the suspension is studied in detail to optimize the suspension chemistry. Due to broad size distribution of YSZ particles in the initial suspension, supernatant is taken after centrifugation for subsequent EPD. This supernatant suspension produced uniform deposit with high packing density (in as-deposited stage) onto non-conducting NiO-YSZ porous substrate. Such as-deposited film resulted in thin and dense YSZ coating (thickness ∼ 3 μm) when fired at 1200 °C/2 h. The half-cells (anode + electrolyte) thus obtained is then used to construct SOFC coupon cell by applying a screen-printed La0.65Sr0.3MnO3 cathode layer on the top of the electrolyte. A maximum current density of 1.08 Acm−2 is obtained at 800 °C and 0.7 V using hydrogen and oxygen as fuel and oxidant respectively.