SYNTHESIS OF NANOCRYSTALLINE CE0.9GD0.1O1.95 SOLID ELECTROLYTE BY POLYMER COMPLEX METHOD
Keywords:
Polymer Complex Method, Nanocrystalline Powder, GDC Electrolyte, Electrical ConductivityAbstract
Gadolinium-doped ceria (GDC) is to date the most promising solid electrolyte to replace the standard yittria-stabilised zirconia as an electrolyte for solid oxide fuel cells (SOFCs) operating at intermediate temperature. In order to synthesize the electrolyte material used at an intermediate temperature, nanocrystalline GDC powder with a composition of Ce0.9Gd0.1O1.95 was successfully prepared by the polymer complex (PC) method. The observation by transmission electron microscopy (TEM) revealed that the prepared nanocrystalline GDC powder had an average particle size of 5.5 nm after calcination at 400OC for 2 h. The x-ray diffraction (XRD) patterns of the calcined powders showed a pure cubic fluorite phase. For the electrical property, the total conductivity of the Ce0.9Gd0.1O1.95 pellets sintered at 1400OC for 4 h was found to be 1.52 S/m at 600OC with the activation energy (Ea) of 0.75 eV in the temperature range of 300-600OC, which results are in the same range as commercial powders produced by combustion spray pyrolysis. This study shows that the simple and low cost PC method could be a good candidate for making nano-sized GDC electrolyte for SOFCs.
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