ZHU Minzheng 1, 2, YANG Biao 1, YI Li 1, ZHU Lejie 2
(1. School of Energy Materials and Chemical Engineering, Hefei University, Hefei 230000, Anhui, China; 2. School of Chemistry and Civil Engineering, Shaoguan University, Shaoguan 512000, Guangdong, China)
Abstract: Bi1.8SrxGd0.1Er0.1−xO3 (0≤x≤0.08) electrolyte materials were prepared by using a sol-gel method. The samples were analyzed by using thermogravimetric differential thermal analysis, infrared spectrometer, X-ray diffraction (XRD), scanning electron microscopy (SEM), Archimedes drainage method and AC impedance meter. It is found that the powders calcined at 600℃ are single phase with cubic fluorite structure. The Bi1.8SrxGd0.1Er0.1−xO3ultrafine powders have high sintering activity. After sintering at 800 ℃ for 8 h, the relative density reaches 96%. Grain sizes of the Bi1.8Sr0.06 Gd0.1Er0.04O3 powder are in the range of 3–6 μm, while its relative density reached 98.2%. The electrolyte materials have high conductivity and low conduction activation energy, at the test temperature of 800 ℃. Bi1.8Sr0.06 Gd0.1Er0.04O3showed the maximum conductivity (σ=0.159 S·cm−1) and the minimum conduction activation energy (Ea=0.67 eV).
Key words: SOFC; δ-Bi2O3; doping; sol-gel method; conductivity