Synthesis, stability and conductivity of BaCe0.8−xZrxY0.2O3−δ as electrolyte for proton conducting SOFC

Abstract

Barium cerate has high proton conductivity but poor chemical stability in presence of CO2 as well as H2O. However, barium zirconate is chemically stable but has poor protonic conductivity. To combine above two effects, BaCe0.8−xZrxY0.2O3−δ (BCZY, with x = 0.0, 0.2, 0.4, 0.6 and 0.8) powders were synthesized by a Pechini method. Lattice parameters as generated from X-ray diffraction studies were found to decrease with increase in Zr content. Compositions with x ≥ 0.4, were found to exhibit enhanced chemical stability in presence of carbon dioxide. Proton conductivity of BCZY samples were measured using impedance spectroscopy in moist N2 atmosphere and activation energy for proton conduction was determined. Based on this study, BaCe0.4Zr0.4Y0.2O3−δ composition was suggested as a suitable electrolyte material.