LSM-GDC Composite Cathodes Derived from a Sol-Gel Process

Electrodes consisting of strontium-doped lanthanum manganite (LSM) and gadolinium-doped ceria (GDC) were developed with a modified sol-gel process for honeycomb solid oxide fuel cells based on stabilized zirconia electrolytes. The sol-gel derived cathodes show much lower interfacial polarization resistances than those prepared by slurry coating or spray deposition. The interfacial polarization resistances were 0.65 and at 650 and 750°C, respectively, as determined using impedance spectroscopy. The high performance is attributed to the small grain size, high porosity, and large specific surface area of the cathode, demonstrating the dramatic effect of microstructure on electrode performance.