Preparation and electrical conductivity of BaZr0.8Y0.2O3-δ/(ZrO2)0.92(Y2O3)0.08 proton/oxygen ion conducting composite ceramic

Abstract

To improve the sintering performance of doped barium zirconate, (ZrO2)0.92(Y2O3)0.08 (YSZ) was added and BaZr0.8Y0.2O3-δ (BZY)-x%YSZ (x = 20, 30 and 50% by weight) composite ceramics were prepared by mechanical ball milling combined with high-temperature sintering in air. The crystalline structure, chemical composition, microstructure and electrical properties of the composite electrolytes were characterized by XRD, SEM, TEM, EDS and EIS, respectively. The composite electrolytes only consist of BZY and YSZ phases, and there are no precipitates in BZY/YSZ grain boundaries according to the HR-TEM analysis. YSZ addition can improve the sintering properties of the composite electrolytes. When the composite ceramics with YSZ content of 50 wt% are sintered at 1450 °C for 6 h, the relative density and linear shrinkage are optimal. At 700 °C, the electrical conductivity of BZY-50%YSZ ceramic reaches 1.95 × 10−4 S/cm and 1.67 × 10−4 S/cm in the dry air and moist air, respectively.