Synthesis of BaCe0.7Zr0.1Y0.1Yb0.1O3-δ proton conducting ceramic by a modified Pechini method

BaCe0.7Zr0.1Y0.1Yb0.1O3-δ proton conducting material for intermediate temperature solid oxide fuel cell (IT-SOFC) applications has been prepared by a modified Pechini method. Pure perovskite structured material has been obtained after calcining at temperatures T ≥ 1000 °C. The microstructures of the samples sintered at different temperatures from 1350 to 1550 °C have been evaluated, revealing denser microstructures with higher sintering temperatures. The sample sintered at 1400 °C shows the highest conductivity, indicating that the beneficial effects on conductivity from denser samples is counteracted by the segregation of secondary phases in the grain boundaries at higher sintering temperatures. The thermal expansion coefficient (TEC) for BaCe0.7Zr0.1Y0.1Yb0.1O3-δ is in the range of 9.1–9.8 × 10− 6 K− 1 from 25 to 1200 °C, favorably matched to that of Pr based perovskite cathode materials for SOFC applications.

Research Highlights
► BaCe0.7Zr0.1Y0.1Yb0.1O3-δ proton conductor was prepared by a modified Pechini method.
► Sample sintered at 1400°C showed the highest conductivity.
► Secondary phase segregation deteriorated conductivity for samples sintered > 1400 °C.
► The TEC value is favorably matched to that of Pr based perovskite cathode materials.