The effect of Fe doping on the properties of SOFC electrolyte YSZ

Pure YSZ (8 mol% yttria stabilized zirconia) and Fe-doped (2 mol% and 4 mol%) YSZ electrolytes were prepared and sintered at 1200 °C and 1400 °C, respectively by solid state method. Their crystal structure, microstructure, sintering behavior, electrical conductivity, and performance as SOFC electrolyte were investigated. Fe can be dissolved into YSZ lattice and decrease the lattice parameter. When sintered at 1200 °C, Fe dopant can make the YSZ electrolyte denser and increase its total conductivity. When sintered at 1400 °C, the total conductivities of samples decrease for higher Fe dopant concentrations though the densities of samples increase. All the SOFCs with Fe-doped YSZ electrolytes show better performance than those with Fe-free electrolytes. The mechanisms of the effect of Fe doping on the properties of YSZ were analyzed.