Effect of La 0.1 Sr 0.9 Co 0.5 Mn 0.5 O 3− δ protective coating layer on the performance of La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3− δ solid oxide fuel cell cathode

This study investigates the interface reactivity between Lam Sr0.9Co0.5Mn0.5O3-delta (ESCM) protective coating layer and Crofer22H interconnects. Additionally, we report the mechanism of Cr poisoning of the La0.6Sr0.4Co0.8Fe0.2O3-delta (LSCF) cathode's electrochemical properties. The phase, chemical composition, and element distribution of compounds formed at the LSCM-Crofer22H interface are analyzed by X-ray diffraction (XRD) and electron dispersive microscopy (EDS). After heat treatment at 800 degrees C for 100 h, the LSCM/Crofer22H sample contains SrCrO3, a compound with good conductivity; the area specific resistance (ASR) for the LSCM/Crofer22H interconnect is approximately 17-40 m Omega cm(2). We found that the amount of (Mn0.98Fe0.02)(Mn0.02Fe0.48Cr1.5)O-4, Cr3O4, and (Fe,Cr)(2)O-3 oxides form in LSCF/LSCM/Crofer22H is significantly less than that in LSCF/Crofer22H. LSCF conductivity after heating at 800 degrees C for 100 h, is notably higher when in contact with LSCM/Crofer22H than it is when in contact with Crofer22H. These results demonstrate that the LSCM protective coating prevents LSCF cathode poisoning by Cr evaporated from the Corfer22H interconnects. (C) 2011 Elsevier B.V. All rights reserved.