A stable BaCe0.7Ta0.1In0.2O3−δ electrolyte membrane for proton-conducting solid oxide fuel cells

In and Ta co-doping BaCeO3−δ (BaCe0.7Ta0.1In0.2O3−δ) powders were synthesized by an improved route combining solid state reaction and wet chemical method. Green BaCe0.7Ta0.1In0.2O3−δ (BCTI) |NiO+BaCe0.7Zr0.1Y0.2O3−δ (BZCY) half cells were successfully fabricated by co-pressing BCTI powders on NiO–BZCY substrate, which were sintered at a relatively low temperature of 1300 °C for 5 h and then produced dense BCTI membrane. The stability testing showed that BCTI membrane is excellently stable against carbon dioxide and boiling water. A single fuel cell with 44 μm-thick BCTI electrolyte was assembled by brushing Sm0.5Sr0.5CoO3−δ Ce0.8Sm0.2O2−δ (SSC–SDC) composite cathode on dense electrolyte membrane, which generated maximum power densities of 59, 49, 34 mW/cm2 at 650, 600 and 550 °C, respectively. Meanwhile, the resistances of the cell were measured by electrochemical impedance spectroscopy under open circuit condition. Moreover, the long-term test of the cell showed stable power output and open circuit voltages. The above described performance indicates that BCTI is stable electrolyte material for intermediate-temperature solid oxide fuel cells. Besides, the super stable electrolyte material can be used as online high-temperature hydrogen sensor.