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

In order to improve the chemical stability of BaCeO3, Ti4+ was introduced into B site of BaCeO3 to modify the chemical stability. XRD test demonstrates that BaCe0.6Ti0.2Y0.2O3-delta (BCTY) keeps its original pervoskite-type structure at a high doping level of 20%. After exposure in 94% N-2+ 3% CO2+ 3% H2O at 700 degrees C for 10 h, BCTY exhibited adequate chemical stability while decomposition was found in BaCe0.8Y0.2O3-delta (BCY). Accordingly, the conductivity of BCTY reaches 0.0072 S/cm at 700 degrees C in humidified hydrogen which is a little lower than BCY (0.0085). Besides, BCTY displayed better sintering characteristics than BCY at high temperatures and the relative density reaches 96.4% and 94.8%, respectively. The two samples also exhibited similar thermal expansion behavior from 30 to 1,000 degrees C. A fuel cell with BCTY as electrolyte exhibited 244 mW/cm(2) at 700 degrees C and the stable short-term performance further proved the stability of BCTY.