Application of sonochemical processing to LSC(La0.6Sr0.4CoO3)/SDC(Sm2O3-doped CeO2) composite cathodes for solid oxide fuel cells involving CeO2-based electrolytes

Nanocrystalline Sm2O3-Doped CeO2 (SDC) powders were synthesized in a single- and two-phase material system by using sonochemical processing with high-frequency agitation. The synthesized SDC nanocrystalline powders were used to coat the mixed-conducting La0.6Sr0.4CoO3 (LSC) cathode materials. The combined synthesis processing allows the artificial coating of the LSC materials with the ionic-conducting SDC electrolyte. The electrochemical polarizations of the SDC/LSC composites are characterized using a geometrically constricted contact between the ionic probe and the SDC/LSC composites. The lowest cathode polarization was obtained for the LSC (85 wt%)/SDC (15 wt%). The lowest electrode polarization is believed to result from the high density of the triple-phase boundaries when the constituent phases are interconnected in a 3-dimensional manner.