The effects of NiO addition on the structure and transport properties of proton conducting BaZr0.8Y0.2O3-δ

20 mol% yttrium doped barium zirconate, BaZr0.8Y0.2O3-delta (BZY), a proton-conducting electrolyte with 2 wt.% NiO, has been successfully prepared by a solid state reaction and sintered at 1450 degrees C for 5 h. The pellets sintered under O-2 show relative density higher than 95%. The total conductivity of BZY with 2 wt.% NiO in wet Ar is 3.1 x 10 (3) S cm(-1) at 600 degrees C, which is similar to values previously reported for BZY with the aid of sintering and smaller than that of pristine BZY. The hydration constant of BZY with 2 wt.% NiO is determined by thermogravimetry and the obtained result is in good agreement with pristine BZY. The total ion transport number of BZY with 2 wt.% NiO exceeds 0.92 at temperature of 500-800 degrees C. The maximum power density of the electrolyte supported cell (Pt/BZY/Pt) is 5.5 mW cm(-2) at 700 degrees C, which is comparable to the pristine BZY electrolyte supported cell. (C) 2014 Elsevier B.V. All rights reserved.