Process-Property Relation of Protonic Ceramic Electrolytes

The influence of the sintering temperature and ratio of zirconium to cerium on the properties of B-site dopants of BaZrxCe0.8-xY0.1Yb0.1O3-δ (BZCYYb) is studied. The experimental results reveal that the secondary phase formation is more pronounced as the sintering temperature and cerium content increases. At high sintering temperatures, barium defects and cerium loss due to barium evaporation cause the migration of the B-site material, which is the cause of the Y/Yb dominant secondary phase. In addition, variations in the electrochemical performance with changes in the electrolyte and sintering conditions are studied by fabricating a thin film of BZCYYb on an anode-support cell. Irrespective of the composition ratio of the electrolyte, at a sintering temperature of 1400 °C or higher, an increase in the resistance at the interface due to the Y/Yb secondary phase increases the ohmic resistance. At a sintering temperature of 1300 °C, a high ohmic resistance is observed owing to the insufficient densification of the electrolyte. The sample sintered at 1350 °C exhibits the best performance and a low resistance at 500 °C. Therefore, the BZCYYb 2611 cell sintered at 1350 °C is chemically stable and exhibits the best performance among the studied samples.