Investigation of structural, electrical and electrochemical properties of La_0.8Sr_0.2Mn_1−xSc_xO_3−δ as cathode on yttria-stabilized zirconia electrolyte for intermediate temperature solid oxide fuel cell fabricated by one step dry pressing method

La_0.8Sr_0.2Mn_1−xSc_xO_3−δ perovskite oxides (x = 0.00, 0.05, 0.10, 0.15) were systematically examined as cathode materials for intermediate temperature solid oxide fuel cells (IT-SOFCs). This study encompassed structural attributes, temperature-dependent weight variations, the electrical conductivity of La_0.8Sr_0.2Mn_1−xSc_xO_3−δ compositions, and the single-cell electrochemical performance of La_0.8Sr_0.2Mn_1−xSc_xO_3−δ on yttria-stabilized zirconia (YSZ). Further characterizations were carried out through powder X-ray diffraction (XRD), thermogravimetric analysis, DC four-probe method, and impedance spectroscopy, respectively. The X-ray diffraction (XRD) analysis revealed a clear correlation between the increase in Sc³⁺ content at the B-site and an increase in both the lattice parameter and lattice volume. The electrical conductivity of La_0.8Sr_0.2Mn_1−xSc_xO_3−δ compounds at 750 °C were found to be 137.941, 198.07, 119.789, and 61.036 S cm⁻¹ for x = 0.00, x = 0.05, x = 0.10, and x = 0.15, respectively. When combined with YSZ in a single cell, the area-specific resistances for La_0.8Sr_0.2Mn_1−xSc_xO_3−δ were varied between 0.56 and 2.2 Ω cm². La_0.8Sr_0.2Mn_0.95Sc_0.05O_3−δ exhibited enhanced electrocatalytic activity, with an exchange current density of 39.35 mA cm⁻² at 750 °C suggesting the composition as a potential candidate for cathode material in IT-SOFC.