Effect of Nickel Addition on Sintering Behavior and Electrical Conductivity of BaCe0.35Zr0.5Y0.15O3-δ

The effect of different Ni-containing additives on the sintering behavior and electric conductivity of the proton conducting electrolyte BaCe0.35Zr0.5Y0.15O3-delta (BCZY5) was investigated. Ni-doped, NiO-added, and BaY2NiO5(BYN)-added (all 4 mol%) BCZY5 samples were prepared by the solid state synthesis method and sintered at 1400 degrees C for 6 h. Among the three samples, the onset of densification was observed at the lowest temperature for NiO-added BCZY5, which is attributed to the formation of an intermediate phase at a low melting temperature. The BYN-added sample, where no consumption of the constitutional elements of the electrolyte was expected during sintering, exhibited the highest electrical conductivity whereas the doped sample had the lowest conductivity. The electrical conductivities at 500 degrees C under humid argon atmosphere were measured to be 2.0, 4.8, and 6.2 mS center dot cm(-1) for Ni-doped and NiO- and BYN-added samples, respectively.