Influence of sintering activators on electrical property of BaZr0.85Y0.15O3-δ proton-conducting electrolyte

In this study, the influence of CuO and ZnO sintering activators on the densification behavior, distribution of sintering activators, and electrical properties of Y-doped BaZrO3-delta proton conducting oxide were examined over a wide range of oxygen and water vapor partial pressures. With the use of 1 mol% CuO and 4 mol% ZnO, a relative density above 97% was achieved at sintering temperatures of 1500 degrees C and 1300 degrees C, respectively. The bulk and grain boundary conductivities of fully sintered BaZr0.85Y0.15O3-delta, Ba(Zr0.84Y0.15Cu0.01)O3-delta, and Ba (Zr0.81Y0.15Zn0.04)O3-delta were assessed using electrochemical impedance spectroscopy. The amount of sintering activators incorporated into the bulk was investigated using an energy dispersive spectrometer equipped with a high-resolution transmission electron microscope, whereas the equilibrium concentrations of proton and oxygen vacancies as a function of water vapor pressure were estimated by thermogravimetric analysis. Using these results, the total electrical conductivities of the three compositions at 800 degrees C over a wide range of oxygen and water vapor partial pressures were analyzed via a non-linear fitting based on the defect structure of Y-doped BaZrO3-delta. As a result, the proton, oxygen ion, and hole partial conductivities were calculated, and the proton transference numbers of the three compositions were compared.

Automated summary

This study investigated the influence of CuO and ZnO sintering activators on the densification behavior, distribution of sintering activators, and electrical properties of Y-doped BaZrO3-delta proton conducting oxide. The results showed that high relative density can be achieved at specific sintering temperatures, and the proton conductivity and defect structure of different compositions were analyzed to compare their performance.