Preparation of SOFC Cathodes by Infiltration into LSF-YSZ Composite Scaffolds

Fabrication of SOFC cathodes by infiltration of La 0.8 Sr 0.2 Co 0.2 Fe 0.8 O 3-δ (LSCF) into porous scaffolds that were 50-wt% composites of La 0.8 Sr 0.2 FeO 3-δ (LSF) and YSZ were investigated for purposes of reducing the number of infiltration steps required to make conductive electrodes. XRD patterns of porous, LSF-YSZ composites prepared by tape casting and calcined to 1723 K showed only fluorite and perovskite phases and were sufficiently conductive that 30-μm thick films attached to YSZ electrolytes did not substantially contribute to the ohmic resistance in symmetric cells or SOFC. Non-ohmic losses at 973 K were reduced from 1.4 Ωcm 2 to 0.16 Ωcm 2 by two infiltration cycles of LSCF.