Electrolyte-supported IT-SOFC with LSCF–SCFN composite cathode

In this work the evaluation of the usage of LSCF–SCFN composite cathode for intermediate temperature solid oxide fuel cell is presented. For the cathode preparation, typically used perovskite oxide La0.8Sr0.2Co0.2Fe0.8O3–δ was mixed with different quantities of highly catalytic SrCo0.2Fe0.6Ni0.2O3–δ material. The obtained cathode pastes were used in the construction of identical, electrolyte-supported IT-SOFC cells, consisting of the composite cathode, Ce0.85Gd0.15O1.925 electrolyte and 8YSZ–Ni cermet anode. Open circuit voltage (OCV), current density–voltage and cell power density characteristics were measured in the 600–800 °C temperature range. Additionally, the analysis of recorded impedance spectra allowed us to determine the temperature dependence of ohmic resistance, charge transfer resistance and diffusion resistance of the cells. ing to the cell with unmodified cathode, substantial increase (60%–70%) of the maximum power density was observed for the cell with cathode modified by an addition of 20 wt.% of SrCo0.2Fe0.6Ni0.2O3–δ. Such an increase occurred despite that the impedance spectroscopy measurements suggest that the ohmic resistance of the electrolyte is a power limiting factor of the constructed cells.