A niobium and tungsten co-doped SrFeO3-δ perovskite as cathode for intermediate temperature solid oxide fuel cells

Nb and W co-doped SrFeO3-delta perovskite SrNb0.1W0.1Fe0.8O3-delta (SNWF) is exploited as a novel cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). SNWF has a cubic structure with Pm 3 m space group. Its thermal, electrical and electrochemical properties were examined in detail. Nb/W co-doping increased the oxygen vacancy density of SNWF in comparison with that of Nb and W single-doped SrNI30.2Fe0.803.6 (SNF) and SrW0.2Fe0.8O3-delta (SWF) perovskites. Nb/W co-doping resulted in the decrease of electrical conductivity and the enhancement of thermal expansion coefficients (TECs) as well as the electrochemical performance. The average TEC value during 30-1000 degrees C is 19.6 x 10(-6) K-1 for SNWF. At 750 degrees C, the area specific resistance (ASR) and the maximum power density are 0.113 Omega cm(2) and 832 mW cm(-2) for the cells based on SNWF electrode and La0.8Sr0.2Ga0.8Mg0.1O3 (LSGM) electrolyte. Good ORR activity and output performance indicate SNWF can be a good alternative cathode material for IT-SOFC.