Ba(Sr)Zr(CoFe)O3Particledispersed Ba0.5Sr0.5Co0.8Fe0.2O3-δMixed Conductor Composite

Dense oxygen permeable membranes are expected to have great impact on oxygen production and oxygeninvolved industrial processes. Ba0.5Sr0.5Co0.8Fe0.2O3-δ is of highest oxygen permeability at elevated temperatures. A novel composite ceramic preparation route for Ba0.5Sr0.5Co0.8Fe0.2O3-δ was developed by directly produced stable BaZrO3based secondary phase particles(SPP) via addition of ZrO2 and isomolar excess BaO, aiming at improving mechanical properties. It revealed that assynthesized composites could get a welldeveloped and finegrained microstructure, there being secondary phase particles as the grain growth inhibitor, and the mechanical properties and oxygen permeation are improved. For the composite with addition of 10% ZrO2+10% BaO, a welldeveloped and finegrained microstructure has been obtained. Compared to the pure phase BSCF5582, the threepoint bending strength of the composite with addition of 5% ZrO2+5% BaO increases by 68% and its oxygen permeation rate is much higher below 850℃ with the smaller apparent activation energy. Additionally, the electrical properties of the composites are also affected by the inclusion of SPP: conductivity decreases with the SPP content increasing, while the hysteresis of conductivity declines due to the relative stable carrier concentration.