A stable La1.95Ca0.05Ce2O7−δ as the electrolyte for intermediate-temperature solid oxide fuel cells

The La1.95Ca0.05Ce2O7−δ (LCCO) material is successfully synthesized using the Pechini method. The synthesized powders are exposed to atmospheric CO2 and H2 with 3% H2O at 700 °C. The treated LCCO powders are investigated using X-ray diffraction (XRD) to study the chemical stability. According to the XRD results, LCCO is very stable and shows no reactions with CO2 or H2O. A fuel cell with the LCCO electrolyte is prepared using the suspension spray method and is tested in the range from 600 °C to 700 °C using humidified hydrogen (∼3% H2O) as the fuel and static air as the oxidant. An open-circuit potential of 0.832 V and a maximum power density of 259 mW cm−2 are obtained for a single cell with an interface resistance of 0.23 Ω cm2 at 700 °C.

► We prepare a novel electrolyte La1.95Ca0.05Ce2O7−δ for proton-conducting SOFCs. ► The electrolyte is very stable in CO2 at 700 °C for 100 h. ► The electrolyte is very stable in boiling water for 100 h. ► We prepare the electrolyte with the in situ reaction method.