Electrophoretic deposition of YSZ electrolyte coatings for solid oxide fuel cells

The main purpose of this study was to create crack-free thin film electrolyte coatings for solid oxide fuel cells at low cost. Electrophoretic deposition (EPD) technique was employed to prepare dense yttria-stabilized zirconia (YSZ) thin films on stainless steel and porous strontium-doped lanthanum manganite (LSM) substrates. The LSM substrates were produced by slurry casting and subsequent sintering. The suspensions of YSZ were prepared in pure acetylacetone, ethanol, and in mixtures of the two. The deposition experiments were performed with the YSZ suspensions in different solvents to examine the effects of the solvent on the EPD behavior. The effects of current density and powder concentration on the EPD rate were also studied. The deposited films were dried at room temperature and then sintered at high temperatures. The microstructures of the sintered coatings were observed with scanning electron microscopy. By using a partially sintered LSM substrate and an optimized set of deposition conditions, dense and continuous YSZ thin film coatings with thicknesses less than 10 μm were achieved.