A stable BaCeO3-based proton conductor for intermediate-temperature solid oxide fuel cells

BaCe1−xGaxO3−δ (x = 0.1, 0.2) and BaCe0.8Y0.2O3 (BCY) powders are successfully synthesized by a solid-state reaction method. According to thermal gravity analysis in the atmosphere of CO2, BaCe0.9Ga0.1O3−δ (BCG10) and BaCe0.8Ga0.2O3−δ (BCG20) are quite stable while BaCeO3 shows obvious reaction and decomposes into CeO2 and BaCO3. A fuel cell with electrolyte of BaCe0.8Ga0.2O3−δ is prepared by a suspension spray combining with in situ sintering method and tested from 600 to 700 °C with humidified hydrogen (∼3% H2O) as the fuel and the static air as the oxidant. An open-circuit potential of 0.99 V and a maximum power density of 236 mW cm−2 are obtained for the single cell with an interface resistance 0.32 Ω cm2 at 700 °C.