Preparation And Sintering Behaviors Of The BaZr_0.9Y_0.1O₃Proton Conductor

Solid oxide fuel cells （SOFCs） provide many advantages over other type offuel cells because of high energy conversion efficiency,no pollutants,fuel flexibilityand environmental safety. High temperature proton conductors （HTPCs） oxideshave gained widespread interest as electrolyte materials alternative to oxygen-ionconductors because water vapor produces at anode side without diluting the fuel,which reduced the complexity of battery systems.Compared to other proton conductors,zirconium barium based protonconductor is chemically stable in intermediate temperatures rang of400℃⁷00℃,as no reaction with acidic gases such as CO2happen,together with no water vapourto form carbonates and hydroxides. However, zirconium barium electrolyte has poorconductivity due to higher grain boundary resistance since poor sinteringbehavior.Therefore,improvement of the zirconium barium matrix sinteringperformance is one of the research focuses for the realization of applications.In this paper, nanoceramic powders of proton conducting BaZr0.9Y0.1O3-delta(BZY₁₀) have been prepared at low crystallization temperature by inorganic sol-gelsynthesis route. Fators that influencing the performance of BZY₁₀powder, includingthe calcined temperature,pH,complexing agents,holding time were investigated onmorphology of the crystal, average particle size and barium carbonate （BaCO₃）content. It is found that when the calcined temperature is1000°C,pH=8⁹,theration of citric acid to EDTA is1,the average particle size is the smallest，regardless of the holding time.Different content of lithium oxide （Li₂O）,zinc oxide （ZnO） and bismuth oxide（Bi₂O₃） sintering aids were investigated on the zirconium barium morphology,sintering properties and electrical conductivity,and the sintering aids5mol%ofBi₂O₃dopanted electrolyte sintering temperature move up by about100℃and at1500℃, the relative density ofelectrolyte is up to95%,so5mol%of Bi₂O₃playsthe best role.The shrinkage rate and the sintering activation energy have been studied forBZY₁₀with5mol%Bi₂O₃. It is found that the activation energy Q is5.01±0.6eV.