Preparation And Application Of Barium Zirconate-based Proton Conductors

Y-doped BaZrO3 proton conductors show protonic conductivity under containing hydrogen atmosphere at elevated temperatures.With the combining merits of chemical stability and high bulk conductivity,but it have the poor sinterability and extremely high grain boundary resistance.The sinterability and electrical conductivity are improved by doping metal elements and adding sintering additives.A double-sintering aid of CH3COOLi/Zn(NO3)2·6H2O was evaluated the sinterability of BaZr0.8Y0.2O3-?.The BaZr0.8Y0.2O3-? with 2 mol%CH3COOLi/2 mol%Zn(NO3)2·6H2O as double sintering aid was sintered at 1400 ? for 8 h.The BaZr0.8Y0.2O3-? sample achieved the relative bulk density of 95.6%,and the conductivity of 6.90×10-3 S·cm-1 at 700 ? in wet air atmosphere.The hydrogen permeation flux reached up to 0.09 mL·min-1·cm-2 at 800 ? with 1.0 mm thickness when the flow rates of the 50%H2/N2.A new chemically stable proton conductor BaZr0.8-x Hfx Y0.2O3-?(0.05?x?0.25)was synthesized by the solid state method.A doping metal element of Hf was evaluated the sinterability and the electrical conductivity of BaZr0.8Y0.2O3-?.The BaZr0.6Hf0.2Y0.2O3-? was sintered at 1400 ? for 8 h.The BaZr0.6Hf0.2Y0.2O3-? sample achieved the relative bulk density of 94.79%,and the conductivity of 8.42×10-3 S·cm-1 at 700 ? in wet air atmosphere.The sintering aid of Zn(NO3)2·6H2O,CH3 COOLi,Ni O was evaluated for the sinterability of BaZr0.6Hf0.2Y0.2O3-?.The BaZr0.6Hf0.2Y0.2O3-? with 4 mol% Zn(NO3)2·6H2O as sintering aid was sintered at 1400 ? for 8 h,which is 200 ? lower than the sintering temperature of BaZr0.6Hf0.2Y0.2O3-? with no sintering aid.The sample achieved the relative bulk density of 95.75%,and the conductivity of 8.74×10-3 S·cm-1 at 700 ? in wet air atmosphere.