A comparative study on manganese-doped lanthanum-strontium chromite mixed with 8YSZ and 10ScSZ in oxidizing and reducing atmospheres

This paper reports a comparative assessment of the chemical and structural stability of LSCM perovskite composites fabricated with 8YSZ and 10ScSZ. Role of oxidizing and reducing atmospheres are examined on the processing and electrochemical performance of the composites. Higher density is obtained during the sintering of LSCM mixed with 10ScSZ when compared to composite mixtures containing 8YSZ in oxidizing as well as reducing atmosphere. Above composites also densified more in Ar-3%H2-3%H2O atmosphere than air along with the formation of SrZrO3 in reducing atmosphere. MnCr2O4 formation is found only in LSCM-8YSZ composite in Ar-3%H2-3%H2O. Electrochemical tests conducted using symmetric cell configurations indicates low polarization resistance and higher performance for Gas (air/fuel)/LSCM-10ScSZ//8YSZ/LSCM-10ScSZ/Gas (air/fuel). Unlike cell containing LSCM-8YSZ composite, no significant changes are identified in the polarization resistance of LSCM-10ScSZ cell for 80 h. Sr-segregation on the surface of LSCM in electrically tested LSCM-8YSZ cell is attributed to performance degradation in the reducing atmosphere.