Doped Bismuth Ferrite-based Perovskite Type Cathode Materials for IT-SOFCs
Date Issued
2016
Date
2016
Author(s)
Wang, Dan
Abstract
The effects of nickel, cobalt and manganese doping in bismuth-based ferrite perovskite (Bi0.7Sr0.3FeO3-δ) used as cathode of solid oxide fuel cells have been investigated in this study. The cathode powders were synthesized by EDTA-citric acid method. The phase purity of synthesized perovskites were analyzed by X-ray Diffraction (XRD). The solubility limit of Ni was 3 at%, while Mn can substitute for Fe at least 50 at% in BSF. Electrical conductivity by 2-probe and 4-probe DC methods showed that the 50 mol% doping of Mn on B-site improved the electrical conductivity significantly. The oxygen nonstoichiometry was analyzed by X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) to reveal the deficiency of oxygen and ionic conductivity in the ferrites. The ionic conductivity of BSF was 4.21 x10-3 S.cm-1 at 800 oC. Anode disk of 300 μm thick coated with thin layer (μm layer thickness) of electrolyte by spin-coating method. The polarization resistance and contact resistance of the half-cell with an 8YSZ-N flat layer and cathode sintered by different sintering temperatures were analyzed by electrochemical impedance spectra analysis (EIS). Finally, the optimal cathode (Bi0.7Sr0.3Fe0.5Mn0.5O 2.88-0.034+20 SDC) was assembled to a full cell and the maximum power output was 119 mW.cm-2 at 800 oC.
Subjects
bismuth-based ferrite perovskite
cathode
conductivity
oxygen nonstoichiometry
SOFC
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-105-R03527068-1.pdf
Size
23.54 KB
Format
Adobe PDF
Checksum
(MD5):5023bc03b442888bd2a826ed0d8263a5