Dense YSZ electrolyte films prepared by modified electrostatic powder coating

A dense yttria-stabilized zirconia (YSZ, 8 mol% Y2O3) film was successfully fabricated by an electrostatic powder-coating process associated with suspension modifying on a porous anode (NiO/YSZ) substrate. The YSZ green powder layer formed by the unmodified process consisted of the loosely packed particles and could not be densified by sintering. After modifying this green layer by a suspension, a dense wet layer was formed that could be sintered at 1450 °C. SEM observations showed the film to be dense and approximately 8 μm thick. A single cell with this YSZ electrolyte on Ni/YSZ anode and Ag as cathode was assembled and tested in the temperature range from 550 to 750 °C. The open circuit voltage (OCV) and peak power density of the single cell at 750 °C was 1.1 V, which is very close to the theoretical value, and 142 mW/cm2, respectively. The results illustrate that YSZ membranes fabricated by this process are quite dense and gas tight.