(La0.8Sr0.2)0.9MnO3-Gd0.2Ce0.8O1.9 composite cathodes prepared from (Gd, Ce)(NO3)x-modified (La0.8Sr0.2)0.9MnO3 for intermediate-temperature solid oxide fuel cells

Development of high performance cathodes with low polarization resistance is critical to the success of solid oxide fuel cell (SOFC) development and commercialization. In this paper, (La0.8Sr0.2)(0.9)MnO3 (LSM)-Gd0.2Ce0.8O1.9(GDC) composite powder (LSM similar to 70 wt%, GDC similar to 30 wt%) was prepared through modification of LSM powder by Gd0.2Ce0.8(NO3) (x) solution impregnation, followed by calcination. The electrode polarization resistance of the LSM-GDC cathode prepared from the composite powder was similar to 0.60 Omega cm(2) at 750 degrees C, which is similar to 13 times lower than that of pure LSM cathode (similar to 8.19 Omega cm(2) at 750 degrees C) on YSZ electrolyte substrates. The electrode polarization resistance of the LSM-GDC composite cathode at 700 degrees C under 500 mA/cm(2) was similar to 0.42 Omega cm(2), which is close to that of pure LSM cathode at 850 degrees C. Gd0.2Ce0.8(NO3) (x) solution impregnation modification not only inhibits the growth of LSM grains during sintering but also increases the triple-phase-boundary (TPB) area through introducing ionic conducting phase (Gd,Ce)O2-delta, leading to the significant reduction of electrode polarization resistance of LSM cathode.