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

BaCe0.8-xNbxSm0.2O3-delta (x = 0, 0.05, 0.1) powders were prepared by a solid-state reaction method. After boiling in water for 3 h, the BaCe0.8Sm0.2O3-delta powders obviously decomposed into CeO2 and BaCO3 while the other two powder samples containing Nb element in B site were hardly affected. According to thermal gravity analysis, the BaCeo,8Smo.203-6 powders displayed obvious reaction with CO2 while the BaCe0.7Nb0.1Sm0.2O3-delta powders were quite stable. Moreover, the sintered BaCe0.7Nb0.1Sm0.2O3-delta sample exhibited a conductivity value of 0.0026S/cm at 700 degrees C in wet hydrogen. A fuel cell with BaCe0.7Nb0.1Sm0.2O3-delta as electrolyte was prepared by a suspension spray combining within situ sintering method and tested in hydrogen from 600 degrees C to 700 degrees C. The peak power densities respectively reached 245 mW/cm(2) at 700 degrees C, 110 mW/cm(2) at 650 degrees C and 75 mW/cm(2) at 600 degrees C. The interface resistances were 0.31 Omega cm(2) at 700 degrees C, 0.43 Omega cm(2) at 650 degrees C and 1.2 Omega cm(2) at 600 degrees C, correspondingly. (C) 2008 ElsevierB.V. All rights reserved.