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

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 co-dopants in order to enhance conduction and electrocatalytic properties of several LSM-ceria composites. Among the different tested LSM-ceria cathodes, Ce0.8Gd0.1Mg0.1O2−δ-based composite material offers the lowest electrode polarization resistance in the 700–900 °C temperature range. However, at the lowest tested temperatures these results are similar to those obtained for the Ce0.8Gd0.2O2−δ 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 °C), this magnesium-co-doped ceria-gadolinia compound could be an alternative to the widely used Ce1−xGdxO2−δ binary system.

► Composite SOFC cathodes were prepared by mixing LSM and multidoped ceria. ► Total conductivity and electrode polarization were measured and correlated. ► Impedance analysis allowed distinguishing three different electrode contribution. ► The best cathode contained Mg and Gc co-doped ceria mixed with LSM.