Electrophoretic Deposition of Thin Film Zirconia Electrolyte on Non-conducting NiO-YSZ Substrate

Abstract

Eight (8) mol% yttria stabilized zirconia (YSZ), an electrolyte material for solid oxide fuel cell (SOFC), has been deposited onto porous non-conducting NiO-YSZ substrate using electrophoretic deposition technique (EPD) from a stable non-aqueous suspension of YSZ. Normally, EPD cannot be performed on a non-conducting substrate, but, in this present study, YSZ particulate film has been successfully deposited on a non-conducting NiO-YSZ substrate following two different EPD approaches:(a) using a conducting metallic plate on the reverse side of the porous NiO-YSZ anode substrate and (b) using a conducting polymer coated NiO-YSZ substrate. The deposited films are then formed dense coatings of 5-15 µm after sintering at 1400°C for 6 h in air. Surface and cross-sectional morphologies of green and sintered films deposited by different EPD approaches are investigated using SEM. La0.65Sr0.3MnO3 (LSM), a cathode for SOFC, is then screen-printed onto the electrolyte layer of such sintered half cells (anode+electrolyte) prepared by both the above approaches to construct SOFC single cells. A maximum output power density of 0.37 W.cm–2 is obtained using single cells prepared by conducting metallic plate assisted EPD compared to that of 0.73 W.cm–2 for polymer coated at 800°C using H2 as fuel and O2 as oxidant.