Preparation of Pr0.35Nd0.35Sr0.3MnO3−δ/YSZ composite cathode powders for tubular solid oxide fuel cells by microwave-induced monomer gelation and gel combustion synthesis process

A microwave-induced monomer gelation and gel combustion synthesis process was successfully developed to synthesize well-dispersed Pr0.35Nd0.35Sr0.3MnO3−δ (PNSM)/YSZ composite cathode powders for tubular solid oxide fuel cells (SOFCs). The thermo-gravimetric (TG) analysis of as-prepared ash indicated the decomposition process of most of metal nitrates during gel combustion. The X-ray diffraction (XRD) pattern of the powders calcined at 1000 °C showed only pure PNSM and YSZ phase. Transmission electron microscopy (TEM) revealed that the morphology of powders was characterized with the YSZ particles enwrapped by fine PNSM particles so that PNSM/YSZ composite powders were much better-dispersed compared with the powders made simply by mechanical mixing process. The cell made from PNSM/YSZ composite powder showed lower cathode ohmic resistance and polarization resistance, and produced higher power density subsequently.