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

The BaBi 0.05 Co 0.8 Nb 0.15 O 3− 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 BaCoO 3− 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   cm 2 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.