A-deficit LSCF for intermediate temperature solid oxide fuel cells

A-deficit La0.54Sr0.44Co0.2Fe0.8O3 − δ cathode material for intermediate temperature solid oxide fuel cells (IT-SOFCs) was synthesized by a citrate complexation (Pechini) route. Using La0.54Sr0.44Co0.2Fe0.8O3 − δ as cathode material, a superior cell performance with the maximum power density of 309, 470 and 855 mW cm− 2 at 600, 650 and 700 °C was achieved, in contrast with the maximum power density of 266, 354 and 589 mW cm− 2 using conventional La0.6Sr0.4Co0.2Fe0.8O3 − δ as cathode material at the same temperatures. The reason of this improvement was analyzed on the basis of defect chemistry. Thermal shrinkage experiment testified that the oxygen vacancies in La0.54Sr0.44Co0.2Fe0.8O3 − δ are more mobile than in La0.6Sr0.4Co0.2Fe0.8O3 − δ. Furthermore, theoretical calculation in terms of their composition and the shift of peak position in XRD pattern showed that the concentration of oxygen vacancies of La0.54Sr0.44Co0.2Fe0.8O3 − δ is higher than that of La0.6Sr0.4Co0.2Fe0.8O3 − δ. Therefore, the oxygen ion conductivity via vacancies transfer mechanism is enhanced, which induces the polarization resistance of La0.54Sr0.44Co0.2Fe0.8O3 − δ being decreased with a result of cell performance improved.