Effect of Screen-Printing Mesh Opening Diameter on Microstructural and Electrical Properties of La0.6Sr0.4Co0.2Fe0.8O3-delta Thick Films

摘要

The performance of solid oxide fuel cells (SOFCs) is hampered by the large polarization and ohmic losses across the cathode-electrolyte interface. To minimize these losses, in most SOFCs the cathode is obtained by thick-film deposition techniques. Since the properties of such films depend upon the starting materials and screen-printing parameters, the effect of the mesh opening diameter on the physiochemical properties of cathodes for intermediate-temperature (IT)-SOFCs has been studied. Combustion-synthesized La0.6Sr0.4Co0.2Fe0.8O3-delta powder with specific surface area of 11.64 m(2) g(-1) was utilized in film formation. All films were porous in nature, and the thickness was observed to increase with the mesh opening diameter. The electrical conductivity showed a decreasing trend with film thickness. Typically, film with 7 mu m thickness showed moderate conductivity of 16.4 S cm(-1) with E (a) = 0.1 eV.