The slurry and sheet made from Yttria-stabilized zirconia (YSZ) powder are known to be affected by the powder characteristics. For the purpose of controlling the characteristics of YSZ sheet, two types of commercial YSZ powder with different particle sizes were used to produce slurries, with which sheets were molded. Then, the effects of the powder characteristics on the slurry and sheet were observed. As the YSZ particle size diseased, there was an increase in the amount of dispersant required for a stable dispersion, an increase in the viscosity of the slurry and a decrease in the packing density of the sheet. However, a correlation between the packing density and the organic content was not clearly established. In the case of YSZ powder with a particle size of 150 nm, the strength and the elongation both increased along with the rise in the binder content, while a decrease in strength and an increase in the elongation were observed when the plasticizer/binder ratio was increased. As for the YSZ powder with a particle size of 65 nm, almost no correlation was observed between the binder and plasticizer contents and the sheet properties, and low strength and high elongation were observed in all conditions. These tendencies are thought to be caused by the failure of the slurry polymer to perform its intended function after reacting with the metal ions that dissoluve from the surface of the powder particles.

Keywords: SOFC, Tape casting, YSZ, Gelation