Novel BaCe0.7In0.2Yb0.1O3−δ proton conductor as electrolyte for intermediate temperature solid oxide fuel cells

Novel proton conductor BaCe0.7In0.2Yb0.1O3−δ (BCIYb) has been successfully synthesized by a modified Pechini method and characterized as electrolyte for intermediate temperature solid oxide fuel cells. Acceptable tolerance to wet CO2 environment was found during chemical stability tests. No interaction between the BCIYb electrolyte and La0.6Sr0.4Co0.2Fe0.8O3−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−1 at 800 °C in dry air, wet air, wet H2 and wet N2, respectively. The maximum cell power outputs of single cells with the configuration of Ni–BaZr0.1Ce0.7Y0.2O3−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.

► BaCe0.7In0.2Yb0.1O3−δ (BCIYb) proton conductor has been synthesized by a modified Pechini method.
► BCIYb shows acceptable tolerance to wet CO2 environment at 700 °C for 24 h.
► BCIYb shows conductivities of 8 × 10−3 and 4.5 × 10−3 S cm−1 at 800 °C in wet air and wet H2, respectively.
► Single cells with BCIYb as electrolyte showed maximum power output of 0.28 W cm−2 at 700 °C.
► Single cell with BCIYb as electrolyte shows stable performance during the 25-h test at 0.7 V and 600 °C.