| 초록 |
Perovskite oxides such as La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) are cathode materials widely used in solid oxide fuel cells (SOFC) with high catalytic activity and mixed ion and electron ion conductivity (MIEC) [1,2]. However, in the low temperature region (＜750 oC), since the ionic conductivity is generally lowered, it is mixed with an ionic conductive material to lower the cathode polarization resistance [3]. Moreover, much research has been done to effectively improve the oxygen reduction reaction (ORR) activity of the cathode by increasing the surface area with nano-sized of the porous cathode structure. However, nanoparticles are easily agglomerated and difficult to mix uniformly with composite nanoparticles due to its high surface energy, resulting in significant coarsening between adjacent particles during high-temperature heat treatment. In this study, LSCF-GDC nanocomposite powders were synthesized by modified sol-gel method. The physicochemical properties of the synthesized nanocomposite powders such as sintering behavior, phase stability, etc. were investigated. Based on the relative density and total conductivity of the sintered GDC pellets, optimal sintering conditions of GDC nanopowders were assessed. In addition, Electrochemical Impedance Spectroscopy (EIS) was used to evaluate the electrochemical properties of the LSCF-GDC nanocomposite cathodes. The LSCF-GDC nanocomposite cathode's microstructural characteristics were quantified via a 3D reconstruction technique and compared to the electrochemical performance of the Ni-YSZ anode supported single cell SOFC. |
