Sr-Yb Co-doping of BaCe_0.4Zr_0.6O₃ Proton-Conducting Electrolyte for Solid Oxide Fuel Cells

Ba_0.9Sr_0.1Ce_0.4Zr_0.6−xYb_xO_3−δ(x = 0.05, 0.1, 0.15, 0.2) proton-conducting electrolyte powders were synthesized by the nitrate combustion method. The effects of co-doping of Sr and Yb on the phase composition and electrochemical performance were studied. X-ray diffraction (XRD) results indicate that Sr and Yb were successfully doped into the lattice of BaCe_0.4Zr_0.6O₃, forming a single perovskite phase. The AC impedance technique was used to investigate the total conductivity of the materials under air and water vapor atmospheres at 400–800°C. The results show that BSCZY20 demonstrated the highest electrical conductivity of 0.033 S cm⁻¹ at 800°C in water vapor. This suggests that the co-doping strategy can effectively enhance the conductivity of BaCe_0.4Zr_0.6O₃ proton-conducting material, which provides valuable insight for the development of high-performance proton-conducting solid oxide fuel cells.