The phase stability and conductivity of HoO-GdO co-doped electrolyte for solid oxide fuel cell.

Çorumlu, Vahit; Ermiş, İsmail; Acer, Semra; Çifci, Tuğba; Dağdemir, Yılmaz; Ari, Mehmet

In this study, BiO ternary system sample materials were synthesized by using solid state reaction method. Two oxides, HoO and GdO, were used to stabilize the δ (cubic) BiO phase used as an electrolyte of solid oxide fuel cell applications. The characteristics and electrical properties of these electrolyte samples for solid oxide fuel cells were evaluated by X-ray diffraction (XRD), scanning electron microscope and the four-point probe technique. According to XRD measurements, δ-phase (x = 0.05-0.1, y = 0.05, 0.1, 0.15, 0.2) samples were obtained with a stable structure. The results of the electrical measurements of the (BiO)(HoO)(GdO) ternary system show that the electrical conductivity increase with decreasing amount of GdO molar ratio at a fixed molar ratio of HoO. The value of highest conductivity was found as 2.53 × 10 S cm for the (BiO)(HoO)(GdO) ternary system (x = 0.05 mol% and y = 0.05 mol%) at 973 K. It was found that activation energy at low temperature varied from 1.10 to 1.29 eV and the activation energy at high temperature varied from 0.61 to 0.70 eV.

X-ray diffraction; ELECTROLYTES; SOLID oxide fuel cells; ACTIVATION energy; ELECTRIC conductivity

Journal of Materials Science: Materials in Electronics, 2016, Vol 27, Issue 6, p5839

0957-4522

Academic Journal

10.1007/s10854-016-4500-y