Microstructural Control of LSM/YSZ Composite Cathode for Lower Temperature Operation of SOFC

• Published in: 2007 2nd IEEE International Conference on Nano/Micro Engineered and Molecular Systems pp. 316 - 319
• Main Authors: Chaichanawong, J., Sato, K., Abe, H., Murata, K., Fukui, T., Charinpanitkul, T., Tanthapanichakoon, W., Naito, M.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.01.2007
• Subjects: Cathodes; Current measurement; Fuel cells; LSM1YSZ composites; Microstructure; Particle size distribution; Polarization; Powders; Scanning electron microscopy; SOFC; Solids; Strontium; Temperature control
• ISBN: 9781424406104; 1424406102; 1424406099; 9781424406098
• DOI: 10.1109/NEMS.2007.351972

La 0.8 Sr 0.3 MnO 3 (LSM)/Y 2 O 3 stabilized ZrO 2 (YSZ) composite powders were mechanically prepared. By changing the mechanical device or processing time, three composite powders with different size distributions were obtained. Then the powders were formed into cathodes of solid oxide fuel cells (SOFCs). The microstructures of the cathodes were carefully characterized by scanning electron microscope (SEM). Losses by internal resistance (IR) and by polarization between the electrolyte and cathode were measured with the current interruption technique. The cathode fabricated by using the powder with the narrowest particle size distribution showed fine grains, uniform porous structure and good contact with the electrolyte layer, thereby resulting in low IR and polarization losses. In contrast, the cathode fabricated from the powder with the broadest particle size distribution contained a large mass of coarse particles and had less uniform structure in the grains and pores, thereby resulting in relatively high IR and polarization losses.