A cobalt-free bismuth ferrite-based cathode for intermediate temperature solid oxide fuel cells

High catalytic activity of cathode material is one of the key requirements for the practical application of solid oxide fuel cells (SOFC). Here we designed and evaluated a novel non-metal P-doped (Bi, Sr)FeO3_?, i.e., Bi0.5Sr0.5Fe0.95P0.05O3_? (BSFP) oxide, as cathode material. BSFP with a cubic structure presents excellent chemical compatibility with Ce0.9Gd0.1O1.95 (GDC) electrolyte after sintering at 1100 ?C. Impedance analysis reveals its polarization resistance (Rp) is as low as 0.18 0 cm2 at 700 ?C. Further kinetics study suggests the lowfrequency process is the rate-limiting step of the oxygen reduction reaction (ORR). An anode-supported single cell delivers attractive power output of 0.56 W cm_ 2 at 700 ?C. The electroactivity is superior to undoped (Bi, Sr) FeO3_?, indicating that BSFP perovskite could be a promising cathode for SOFC operating at intermediate temperatures.

Automated summary

BSFP oxide, as a cathode material for SOFC, shows excellent chemical compatibility and low polarization resistance, suggesting its promising application in SOFC operation at intermediate temperatures.