Surface chemistry degradation in La0.6Sr0.4Co0.2Fe0.8O3-d cathodes as a function of aging temperature

BAQUÉ, LAURA; SOLDATI, ANALIA L.; TEIXERA NETO, ERICO; TROIANI, HORACIO; SCHREIBER, ANJA; VOSS, ANDREA; GIEBELER, LARS; SERQUIS, ADRIANA C.

Lucerna

Conferencia; EFCF 2018 - 13th European SOFC & SOE Forum; 2017

European Fuel Cell Forum

This work aims atstudying the degradation of the oxygen reduction reaction (ORR) kinetics at La0.6Sr0.4Co0.2Fe0.8O3-d(LSCFO) cathodes induced by aging at different temperatures (i.e. 700 and 800ºC) in air for up to 240 h. The studied porous cathodes are mainly composed ofparticles within the micrometric range which facilitates the occurrence ofsurface Sr-enrichment[1,2]. The evolution of the cathode electrochemicalproperties was continuously monitored by Electrochemical Impedance Spectroscopy(EIS) during the aging treatment while the surface compositional and microstructuralchanges were characterized before and after the aging treatment by ScanningElectron Microscopy (SEM), Scanning Transmission Electron Microscopy-EnergyDispersive Spectroscopy (TEM-EDS), and inductivelycoupled plasma-opticalemission spectrometry (ICP-OES). This methodology allowed us establishing a correlationbetween the cation surface characteristics and theelectrochemical behavior as afunction of the aging temperature