Nanoarchitectonics of yttrium-doped barium cerate-based proton conductor electrolyte for solid oxide fuel cells

Abstract

As the third generation of fuel cells, solid oxide fuel cell (SOFC) provides a clean and low-pollution technology. Electrolyte material, which often plays a vital role in SOFC, has always been the focus and difficulty of research. Y-doped barium cerate-based proton conductor electrolyte, BaCe_1–xY_xO_3–δ (x = 0, 0.05, 0.1, 0.15), were prepared using the nitrate-citrate-glycine combustion method. A series of tests and characterizations were performed to examine the structural, morphological, and electrical properties. X-ray diffraction (XRD) analysis proved that the BCY powders with pure cubic perovskite structure were formed after calcined at 1100 °C. SEM results showed that the BCY ceramics sintered at 1350 °C were dense and well-developed grains. The electrochemical performance of BCY proton conductor electrolyte was determined using the electrochemical impedance spectroscopy in dry air and wet air atmosphere at 400–800 °C. Results showed that Y-doped BaCeO₃-based material had superior conductivity in air and the conductivity of proton conductor was significantly improved under wet air environment. Furthermore, the electrical conductivity of BCY samples was related to the amount of Y³⁺ doping. The conductivity in a water vapor environment achieved a maximal value of 0.039 S cm⁻¹ at 800 °C when x = 0.15. So BaCe_1–xY_xO₃-based materials can be used as a proton conductor electrolyte for SOFC in the medium temperature range.