Synthesis and characterization of BaZr0.3Ce0.5Y0.2−xYbxO3−δ proton conductor for solid oxide fuel cells

The acceptor-doped BaCeO3-BaZrO3 solid solution shows a good compromise between conductivity and chemical stability. Y and/or Yb doped BaCeO3-BaZrO3 solid solution BaZr0.3Ce0.5Y0.2−xYbxO3−δ (x = 0, 0.05, 0.1, 0.15, 0.2) powders are synthesized via a typical citrate-nitrate combustion method in this work. The crystal structure and electrical conductivity of BaZr0.3Ce0.5Y0.2−xYbxO3−δ are investigated. The XRD results reveal all the powders possess orthorhombic perovskite structure. The electrical conductivity decreases monotonously with increasing the proportion of Yb, and BaZr0.3Ce0.5Y0.2O3−δ exhibits the highest electrical conductivity. Single cells with BaZr0.3Ce0.5Y0.2O3−δ as the electrolyte are fabricated and tested, and the cell outputs excellent power density and stability. The peak power density of the cell reaches as high as 513 and 396 mW cm−2 at 650 and 600 °C, suggesting that BaZr0.3Ce0.5Y0.2O3−δ-based fuel cells are promising solid oxide fuel cells (SOFCs) working at low temperatures.