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

In and Ta co-doping BaCeO3-delta (BaCe0.7Ta0.1In0.2O3-delta) powders were synthesized by an improved route combining solid state reaction and wet chemical method. Green BaCe0.7Ta0.1In0.2O3-delta (BCTI) vertical bar NiO+BaCe0.7Zr0.1Y0.2O3-delta (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 degrees 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 pm-thick BCTI electrolyte was assembled by brushing Sm0.5Sr0.5CoO3-delta Ce0.8Sm0.2O2-delta (SSC-SDC) composite cathode on dense electrolyte membrane, which generated maximum power densities of 59, 49, 34 mW/cm(2) at 650, 600 and 550 degrees 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. (C) 2012 Elsevier Ltd and Techna Group S.r.l. All rights reserved.