Analysis of impact of sintering temperature on microstructure of LSCF-SDC composite cathodes using nano-CT

ABSTRACT Composites of La 0.4 Sr 0.6 Co 0.8 Fe 0.2 O 3i d (LSCF) with samarium doped ceria (SDC) have been extensively used as cathodes for solid oxide fuel cells (SOFCs) to lower its operation temperature. The ability to visualize three-dimensional (3D) microstructural changes in LSCF-SDC composite cathodes can help elucidate the impact of microstructure on cathode performance. This study reports that we utilize the nano-computed tomography (nano-CT) technique to image the 3D microstructures of La 0.4 Sr 0.6 Co 0.2 Fe 0.8 O 3 (LSCF) - Ce 0.8 Sm 0.2 O 1.9 (SDC) composite cathodes which were sintering at 800, 1000, and 1200 o C, respectively, for 2 h based on the Fe K-absorption edge. Using the reconstructions of LSFC-SDC composite cathodes submitted to different temperatures, the key microstructural properties, such as volume fraction of each phase, connected volume fraction, surface area, triple-phase boundary length, and pore size were measured. The effect of sintering temperature on the microstructure of LSFC-SDC cathodes was discussed and compared with theoretical simulation. With increasing sintering temperature in the range from 800 to 1200