Evaluation and performance of cobalt-doped YSZ electrolyte

Cobalt doped yttria-stabilized zirconia (YSZ) was evaluated in terms of sintering behavior, electrical conductivity and microstmcture as well as performance in solid oxide fuel cells. Cobalt addition increased the total electrical conductivity of YSZ, unlike Mn addition which reduced the conductivity. YSZ doped with 1 at% Co has negligible electronic conductivity and is applicable as the electrolyte in galvanic cells. It is shown that cobalt doping reduces the sintering temperature of YSZ. Consequently, cell performance can be enhanced significantly due to the elimination of interface reaction by sintering at a lower temperature.