Preparation And Application Of Proton Conducting Solid Electrolyte With High Stability

With the transformation of the global economic model, the development and utilization of hydrogen energy become very important, while the proton conductors play an important role in this field. Doped BaCeO3 has good proton conductivity at high temperature, but the stability is very poor, which seriously limits its industrial application. Therefore, improving its stability without affecting its electrical conductivity is significant. BaCe_0.9Y_0.1O_3-δ（BCY10） modified by ZnO and Br doped BaCe_0.9Y_0.1O_3-δ were prepared by high temperature solid-state method, and BaCe0.8Y0.2O3-δ-BaZr0.7Pr0.1Y0.2O3-δ（BCY20-BZPY20） with core-shell structure was prepared by sol-gel method. The phase composition, microstructure and electrical properties were characterized by XRD, SEM and AC impedance. At the same time, the stability of CO2 and boiling water was studied. Finally, the material was applied on the impedance-type hydrogen sensor, and the sensitivity to hydrogen was studied.Both of the two modification methods improved the sintering of BCY10. The structure of BCY10 modified by Zn（NO3）2（BCYZn2） was the most dense. The stability test results showed that the stability of BCY10 in CO2 atmosphere was improved, but the stability in boiling water was not improved.BCY20-BZPY20 with dense structure was obtained at 1300 oC. The addition of BZPY20 brought about decline of electrical conductivity, but with the increase of BZPY20, the stability of materials in CO2 and boiling water was enhanced.Br doped BCY10 had formed a good and pure phase. However, the doping of Br had influence on the sintering of materials. As the content of Br increased, the porosity of the material increased and the electrical conductivity decreased. The stability test results showed that the incorporation of Br could improve the stability of BCY10 in CO2. The sensor sensitivity test results indicated that: in a range of hydrogen concentration, the total impedance of the sensor decreased with the increasing of hydrogen concentration. Therefore, the sensor was sensitive to hydrogen concentration.