A cobalt-free bismuth ferrite-based cathode for intermediate temperature solid oxide fuel cells
Juntao Gao, Qiang Li, Zhiping Zhang, Zhe Lü, Bo Wei
Abstract
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−δ, i.e., Bi0.5Sr0.5Fe0.95P0.05O3−δ (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 Ω cm2 at 700 °C. Further kinetics study suggests the low-frequency 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−δ, indicating that BSFP perovskite could be a promising cathode for SOFC operating at intermediate temperatures.