Investigation and optimization of infiltration parameters for nanostructured cathode electrodes in solid oxide fuel cells

This study investigates the effects of various parameters on the performance of solid oxide fuel cells (SOFCs) by focusing on the infiltration of strontium-doped lanthanum manganate (LSM) into porous yttria-stabilized zirconia (YSZ) electrolyte layer. The infiltration process is optimized by adjusting the thickness of the YSZ scaffold, infiltration solution concentration, number of infiltration cycles, and infiltrate sintering temperature through microstructural and electrochemical analyses. Optimal results based on electrochemical performance are achieved with 13 infiltration cycles of a 0.5 M LSM solution into 25 μm thick porous YSZ layer, followed by sintering at a temperature of 1000 °C. The cell attains a maximum power density of 0.546 W/cm2 at 800 °C, whereas the conventional cell, which utilizes a cathode electrode prepared through screen printing of mechanically mixed LSM and YSZ powders, exhibits only 0.172 W/cm2 maximum power density under the same conditions. Additionally, a dual-infiltration approach involving NiO for the anode and LSM for the cathode achieves a peak power density of 0.750 W/cm2 at 800 °C and 0.210 W/cm2 at 600 °C, demonstrating a significant performance improvement along with a reduction of 200 °C in operating temperature without sacrificing the cell performance.