Low temperature processing of interlayer-free La0.6Sr0.4Co0.2Fe0.8O3−δ cathodes for intermediate temperature solid oxide fuel cells

Nanocrystalline La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF) powder with a specific surface area of 22.9 m2 g−1 and an average particle size of 175 nm was prepared by a nitrate-glycine solution combustion method and subsequent ball-milling. The LSCF precalcined at 800 °C (LSCF-800) shows very good low-temperature sintering activity, and can well adhere to electrolyte after sintering at 700 °C and above. The single cell Ni–YSZ/YSZ/LSCF-800 with the cathode sintered at 750 °C demonstrates the lowest polarization resistance and good electrical generation performance, but poor cathode microstructure stability. The sintering activity of LSCF cathode can be tailored through the control of the precalcination temperature of the precursor powder. Precalcining of LSCF powder at 900 °C (LSCF-900) increases the optimum sintering temperature of the cathode to 850 °C and improves the microstructure stability. The cell Ni–YSZ/YSZ/LSCF-900 with this cathode demonstrates excellent generation performances with the maximum power density greater than 1.0 W cm−2 and the power density of above 0.80 W cm−2 at 0.7 V under operation at 700 °C. Low temperature processing of the interlayer-free LSCF cathode with good microstructure is beneficial to simplifying the cell structure and improving fuel cell performance.