Synthesis and characterization of BaBi0.05Co0.8Nb0.15O3−δ as a potential IT-SOFCs cathode material

The BaBi0.05Co0.8Nb0.15O3−δ (BBCN) oxide has been synthesized by the traditional solid-state reaction method and characterized for its application as new cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The single phase BBCN having a cubic perovskite structure is obtained by Bi and Nb doping on the Co site in BaCoO3−δ. The electrical conductivities of the BBCN sample are 8.8-12.5 S cm−1 in the temperature range 600-800 °C in air. The average thermal expansion coefficient (TEC) is 20.7 × 10−6 K−1 in the range of 30-1000 °C in air. The activity of BBCN for oxygen reduction reaction (ORR) is tested by symmetrical cell and single fuel cell tests. The area specific resistance (ASR) of a BBCN cathode with LSGM electrolyte is 0.073 Ω cm2 at 700 °C in air. A maximal power density of 610 mW cm−2 is achieved at 800 °C. The BBCN cathode has shown a good electrochemical stability for 24 h short-term cell test. The experimental results indicate that BBCN can be a promising cathode candidate for IT-SOFCs.