High-performance solid oxide fuel cell based on iron and tantalum co-doped BaCoO3-δ perovskite-type cathode and BaZr0.1Ce0.7Y0.1Yb0.1O3-δ electrolyte

Proton conducting solid oxide fuel cells (H–SOFCs) have attracted much interest for their various advantages. BaZr0.1Ce0.7Y0.1Yb0.1O3-δ (BZCYYb) displays both good proton conductivity and stability among all of the barium zirconate-cerate oxides such as BaZr0.1Ce0.7Y0.2O3-δ (BZCY) with proton conducting. In this study, an Fe and Ta co-doped perovskite-type oxide with the composition of BaCo0.7Fe0.2Ta0.1O3-δ (BCFT) is synthesized by the solid state reaction (SSR) method and studied as a high-performance cathode for H–SOFCs operated between 650 and 800 °C. The BCFT is chemically compatible with BZCYYb electrolyte, even co-sintering at 1000 °C for 10 h. The activating energy (Ea) of electrical conductivity for the BCFT sample is only 0.038 eV. The BCFT demonstrates superior oxygen reduction reaction (ORR) kinetics than that of BaCo0.7Fe0.2Nb0.1O3-δ (BCFN), when the Nb is completely substituted by Ta. The Ea of the polarization resistance (Rp) for BCFT is 0.911 eV, which is 0.11 eV lower than that of BCFN. The peak power density (PPD) of the anode-supported H–SOFC using BCFT is 1.65 W cm−2 and the Rp is 0.01 Ω cm2 at 800 °C. Therefore, the BCFT is a promising cathode for H–SOFCs based on BZCYYb electrolyte.