Composites of Single/Double Perovskites as Cathodes for Solid Oxide Fuel Cells

The state-of-art cathode materials PrBaCo2O5+ (PBC) and La0.4Sr0.6Co0.2Fe0.8O3- (LSCF) are mixed into a composite cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Analysis by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM) demonstrates that a structure comprising a single and double perovskite is obtained upon sintering in air at 1000 degrees C. Possible chemical interdiffusion between PBC and LSCF grains is further investigated by transmission electron microscopy and scanning transmission electron microscopy combined with electron energy loss spectroscopy. The composite cathode PBC+LSCF (with mass ratio 6:4) shows improved performance compared to either PBC or LSCF alone, achieving total area resistance (ASR) values in air of 0.017, 0.032, 0.07, 0.16, and 0.32cm(-2) at 800, 750, 700, 650, and 600 degrees C, respectively. The PBC-LSCF64 cell delivered power densities of 1103mWcm(-2) at 750 degrees C, which were enhanced by 26% and 35% compared to the initial PBC and LSCF powders, respectively.