SOFC composite cathodes based on LSM and co-doped cerias (Ce0.8Gd0.1X0.1O2-d, X = Gd, Cr, Mg, Bi, Ce)

Abstract

Ceria-based materials have been incorporated into LSM conventional cathodes in order to improve the electrochemical performance. Gadolinium and other elements (Mg, Cr and Bi) have been used as ceria codopants in order to enhance conduction and electrocatalytic properties of several LSM-ceria composites. Among the different tested LSM-ceria cathodes, Ce0.8Gd0.1Mg0.1O2-delta-based composite material offers the lowest electrode polarization resistance in the 700-900 degrees C temperature range. However, at the lowest tested temperatures these results are similar to those obtained for the Ce0.8Gd0.2O2-delta binary system, thus the selection of Gd-co-doping elements should principally address economic issues. Since LSM-based cathodes are pointed for high temperature applications (> 800 degrees C), this magnesium-co-doped ceria-gadolinia compound could be an alternative to the widely used Ce1-xGdxO2-delta binary system.