Cerium and niobium doped SrCoO3−δ as a potential cathode for intermediate temperature solid oxide fuel cells

Sr0.9Ce0.1Co0.9Nb0.1O3−δ (SCCN) has been synthesized using solid state reaction, and investigated as a new cathode material for intermediate temperature solid oxide fuel cells (ITSOFCs). SCCN material exhibits sufficiently high electronic conductivity and excellent chemical compatibility with SDC electrolyte. Highly charged Ce4+ and Nb5+ successfully stabilize the perovskite structure to avoid order-disorder phase transition. The electrical conductivity reaches a high value of 516 S cm−1 at 300 °C in air. The area specific resistances of the SCCN-50 wt.% Ce0.8Sm0.2O1.9 (SDC) cathode are as low as 0.027, 0.049, and 0.094 Ω cm2 at 700, 650, and 600 °C, respectively, with the corresponding peak power densities of 1074, 905, and 589 mW cm−2. A relatively low thermal expansion coefficient of SCCN-SDC is 14.3 × 10−6 K−1 in air. All these results imply that SCCN holds tremendous promise as a cathode material for ITSOFCs.