Abstract
La0.6Sr0.4Co0.8Fe0.2O3-delta (LSCF) cathode perovskite prepared by a Pechini method deposited on ceria co-doping Ce(0.8)Sm(0.17)Ln(0.03)O(1.9) (LnSDC), with (Ln = La, Y, and Nd) electrolytes was successfully prepared by the solid-state reaction method. In this preparation process, thick and thin films of LSCF were deposited upon dense Ln-doped ceria LnSDC electrolytes after 5 and 3 spin-coating and dip-coating cycles, respectively. Two layers of LSCF were deposited by screen-printing in order to obtain thick cathode films. After deposition, some structural and morphologic characterizations, such as X-ray diffraction analysis and scanning electron microscopy, have been conducted to understand the properties of the elaborated samples and to study the impact of doping on these properties. Electrochemical impedance spectroscopy measurements on symmetric cells were also performed to investigate the employability of L0.6Sr0.4Co0.8Fe0.2O3-delta as a cathode material deposited upon LnSDC electrolytes for intermediate-temperature solid oxide fuel cells (IT-SOFC). According to what was available and inferred after studying the images from a scanning electron microscope, no cracks or significant segregation were detected in the LSCF/LnSDC interface. This behavior is consistent with the good thermal expansion compatibility between the two materials. Electrochemical impedance spectroscopy investigations at 700 degrees C, indicate relatively low area-specific resistance between 0.048 and 0.1 ohm cm(2) for all symmetrical cell LSCF/doped electrolyte/LSCF. All the cells were previously sintered above 1400 degrees C, in air. All these results showed that L0.6Sr0.4Co0.8Fe0.2O3- delta can stand as a potential candidate for new cathode material in IT-SOFCs.