Novel BaCe0.7In0.2Yb0.1O3-δ proton conductor as electrolyte for intermediate-temperature SOFCs

The novel proton conductor BaCe 0.7 In 0.2 Yb 0.1 O 3-δ (BCIYb) has been successfully synthesized by a modified Pechini method, and characterized as an electrolyte for intermediate-temperature solid oxide fuel cells. Acceptable tolerance to wet CO 2 environment was found during chemical stability tests. No interaction between the BCIYb electrolyte and the La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3-δ (LSCF) cathode was observed during the cathode fabrication process. Further, no detectable impurity phase was found when the BCIYb—LSCF mixed powders were calcined at 700°C for 50 h. BCIYb dense samples sintered at 1450°C for 5 h showed acceptable conductivities of 7.2 × 10 −3 , 8 × 10 −3 , 4.5 × 10 −3 and 3.1 × 10 −3 S/cm at 800°C in dry air, wet air, wet H 2 and wet N 2 , respectively. The maximum cell power outputs of single cells with the configuration of Ni—BaZr 0.1 Ce 0.7 Y 0.2 O 3-δ (BZCY)|BCIYb|BZCY—LSCF were 0.15, 0.218 and 0.28 W/cm 2 at 600, 650 and 700°C, respectively. No cell degradation was observed for cells operated at a constant voltage of 0.7 V in the 25 h short-term durability test.