Enhancement of an IT-SOFC cathode by introducing YSZ: Electrical and electrochemical properties of La0.6Ca0.4Fe0.8Ni0.2O3-δ-YSZ composites

Abstract

Abstract La0.6Ca0.4Fe0.8Ni0.2O3-δ (LCFN) is synthesized by liquid mixed method. Its crystalline structure is investigated by using X-ray diffraction. The results show that it has an orthorhombic perovskite structure with Pnma space group symmetry. The 8\xa0mol % Y2O3-Stabilized ZrO2 (YSZ) is physically mixed with various weight percentages of LCFN to form composite cathodes. High-temperature 4-probe conductivity measurements are performed to investigate the electrical behavior of the system. Electrochemical impedance spectroscopy is carried out using symmetric cells with YSZ substrates under equilibrium condition from 850\xa0°C to room temperature. The electrical conductivity is reduced from 271.3\xa0S\xa0cm−1 to 49.5\xa0S\xa0cm−1 for LCFN and 10\xa0wt % of YSZ-added LCFN (LCFN-YSZ-9010), respectively. The best area specific resistance among all fabricated composites is 0.0080(1) Ω.cm2 at 850\xa0°C for LCFN-YSZ-9010 which exhibits almost 50% lower value than LCFN. The YSZ-based composites appear to be suitable than the other low temperature electrolyte based composite cathodes.