Prevention of SOFC cathode degradation in contact with Cr-containing alloy

The effects of coating materials on Cr-containing alloy separators were examined for preventing the degradation of solid oxide fuel cell (SOFC) performance. Various oxide materials (YSZ, Y2O3, La2O3, LaAlO3 and (La,Sr)CoO3, LSCO) were coated on the alloys, and investigated for the degree of Cr-poisoning using a half-cell measurement method. In these oxides, (La,Sr)CoO3 coating was found to be effective for preventing the degradation. The LSCO-coated alloy was analyzed by X-ray diffractometry (XRD), scanning electron microscope (SEM) and energy dispersion X-ray (EDX) analysis. The interface between the cathode and the electrolyte was examined by electron probe micro analysis. Consequently, it was proved that a LSCO coating controls the growth of the Cr2O3 oxide layer on the Cr-containing alloy surface. And the effects of LSCO coating were further confirmed by a single-cell stack test.