Abstract:
In the fuel cell family, the most competent device for converting energy is the solid oxide fuel
cell (SOFC) and has gained high considerable attention. The efficiency of SOFC highly depends
on electrolyte materials that can work well at low temperatures. Ionic conductivity is good in a
co-doped ceria-based electrolyte material. The most promising electrolyte materials for
intermediate temperature solid oxide fuel cells (IT-SOFCs) have been ceria and doped ceria
because it shows good ionic conductivity at 600-800 ºC which is still very high and a barrier
towards commercialization. Therefore, in this project, the co-doped ceria electrolyte materials
(GBDC, CBDC and SBDC) were developed using sol-gel and co-precipitation method. The
functionalities of electrolyte materials are investigated in this research. Prominent bands at peak
positions 360, 461, 482, 600, 602, 1059 and 1080 cm−1 wavelengths are observed through
Raman spectra of co-doped ceria electrolytes, analogous to GdO F2g mode, the first order F2g
active mode of CeO2's cubic fluorite structure, structure of CeO2 that shows symmetric stretching
modes of O ions around Ce ions, indication of Ca-O, and Ba-O. Ceria based materials behaves as
an excellent electrolyte material. The vibratory characteristics are studied through FTIR
spectroscopy; different peaks are obtained that indicates different vibrational modes. The direct
band gap of the synthesized electrolyte materials were calculated by Tauc plot and obtained 2.5
and 1.5 eV of Gd0.1Ba0.1Ce0.8 .and Ca0.1Ba0.1Ce0.8 respectively. The structural properties are
studied with the help of XRD and obtained a cubic fluorite structure of SBDC electrolyte
material. DC Conductivity measurements of samples are evaluated by four point probe method.
The sample CBDC has maximum ionic conductivity values of 0.82 Scm-1 at 400 ˚C temperature.
The results indicate that developed ceria based electrolytes materials are good for SOFC.