Structural and electrochemical properties of yttrium-doped barium zirconate by addition of CuO

The influences of CuO doping on the sintering behavior, phase formation and electrochemical properties of yttrium-doped barium zirconate were investigated in this study. Unmodified yttrium-doped barium zirconate was difficult to densify. 1-2 mol% CuO can markedly enhance the sinterability of yttrium-doped barium zirconate. No CuO was detected in the CuO-modified samples, which suggested that the CuO might dissolve into the perovskite lattice structure. The electrical conductivity of 1 mol% CuO-modified yttrium-doped barium zirconate was close to that of unmodified one at the testing temperatures ranging from 500 °C to 800 °C in moisture-saturated hydrogen. Electromotive force measurements under fuel cell conditions revealed that the ionic transport number of CuO-modified yttrium-doped barium zirconate was large enough to apply the material as electrolyte in solid oxide fuel cell.