Nano structured lanthanum based iron and cobalt-containing perovskite has a high potential for a cathode material in intermediate temperature solid oxide fuel cells (IT-SOFCs) (700 - 800 οC) due to its high electro-catalytic activity at a relatively low operating temperature. In this study, nanocrystalline La0.58Sr0.4Co0.2Fe0.8O3-δ (LSCF) materials are successfully synthesized using a complex method with carbon black (CB) and aqueous dispersion of carbon black (AqCB) as inorganic nanodisperasnts. When AqCB is used as dispersants, the surface areas of LSCF powder increase from 25 m2g-1 to 40 m2g-1. The cathode sintered at 800 οC of LSCF with CB shows polarizations of 0.10 Ωcm2 and 0.28 Ωcm2 at 700 οC and 650 οC, respectively. The polarizations of LSCF with AqCB are 0.08 Ωcm2 and 0.13 Ωcm2 at 700 οC and 650 οC, respectively. The increment in surface area of AqCB-LSCF results in a lower cathode polarization and a higher electro-catalytic activity. The aqueous dispersion of CB is a good candidate as an inorganic dispersant for synthesis of nanocrystalline cathode materials in views of enhanced catalytic activity and lowered contamination.
Keywords: Solid oxide fuel cell, La0.58Sr0.4Co0.2Fe0.8O3-δ, Nanodispersant, Anode supported cell, Mixed ionic electronic conductor