Investigation of structural, electrical and electrochemical properties of La0.6Sr0.4Fe0.8Mn0.2O3-δ as an intermediate temperature solid oxide fuel cell cathode---International Journal of Hydrogen Energy 45 (2020) 8915

Investigation of structural, electrical and electrochemical properties of La0.6Sr0.4Fe0.8Mn0.2O3-δ as an intermediate temperature solid oxide fuel cell cathode

International Journal of Hydrogen Energy 45 (2020) 8915

ABSTRACT 

La0.6Sr0.4Fe0.8Mn0.2O3 (LSFM) compound is synthesized by sol-gel method and evaluated as a cathode material for the intermediate temperature solid oxide fuel cell (IT-SOFC). X-ray diffraction (XRD) indicates that the LSFM has a rhombohedral structure with R-3c space group symmetry. The XRD patterns reveal very small amount of impurity phase in the LSFM and Y2O3-stabilized ZrO2 (YSZ) mixture powders sintered at 600, 700, 800 and 850 °C for a week. The maximum electrical conductivity of LSFM is about 35.35 S cm−1 at 783 °C in the air. The oxygen chemical diffusion coefficients, DChem, are increased from 1.39 × 10−6 up to 1.44 × 10−5 cm2 s−1. Besides, the oxygen surface exchange coefficients, kChem, are obtained to lie between 2.9 × 10−3 and 1.86 × 10−2 cm s−1 in a temperature range of 600–800 °C. The area-specific resistances (ASRs) of the LSFM symmetrical cell are 7.53, 1.53, 1.13, 0.46 and 0.31 Ω cm2 at 600, 650, 700, 750 and 800 °C respectively, and related activation energy, Ea, is about 1.23 eV.