The phase stability and conductivity of HO2O3-Gd^sub 2^O3 co-doped electrolyte for solid oxide fuel cell

• Published in: Journal of materials science. Materials in electronics Vol. 27; no. 6; p. 5839
• Main Authors: Çorumlu, Vahit, Ermis, Ismail, Acer, Semra D, Çifci, Tuba, Dademir, Yilmaz, Ari, Mehmet
• Format: Journal Article
• Language: English
• Published: New York Springer Nature B.V 01.06.2016
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-016-4500-y

In this study, Bi^sub 2^O3 ternary system sample materials were synthesized by using solid state reaction method. Two oxides, HO2O3 and Gd^sub 2^O3, were used to stabilize the δ (cubic) Bi^sub 2^O3 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 (Bi^sub 2^O3)^sub 1-x-y^(HO2O3)^sub x^(Gd^sub 2^O3)^sub y^ ternary system show that the electrical conductivity increase with decreasing amount of Gd^sub 2^O3 molar ratio at a fixed molar ratio of HO2O3. The value of highest conductivity was found as 2.53 × 10^sup -1^ S cm^sup -1^ for the (Bi^sub 2^O3)^sub 1-x-y^(HO2O3)^sub x^(Gd^sub 2^O3)^sub y^ 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.