Study of Electrochemical and Crystallographic Changes During Initial Stabilization of La0.75Sr0.25Cr0.5Mn0.3Ni0.2O3−δ Reversible Solid Oxide Cell Electrode

Abstract

AbstractThe electrochemical and crystalline structure of mixed ionic‐electronic conductive La0.75Sr0.25Cr0.5Mn0.3Ni0.2O3–δ (LSCMN) electrode in porous scandia ceria stabilized zirconia (ScCeSZ) electrolyte matrix during the first 140 h has been studied in an operando XRD experiment. Intense degradation of electrochemical performance in a fuel cell as well as in electrolysis modes has been observed. However, the mechanism of the degradation was seen to be different for the two operation modes. The formation of the new ceramic phase was observed on the surface of the electrode using the Grazing incidence X‐ray diffraction at the pulsed laser deposited LSCMN model electrode. Instability of the LSCMN phase in the ScCeSZ matrix at SOFC working conditions has been demonstrated using the novel operando XRD technique. The decrease in wt.% of the LSCMN during degradation was approximately 27 ± 4.5%. A slow increase of the ScCeSZ lattice parameter was observed and attributed to the doping of electrolytes with some LSCMN components.