Composite Electrolyte (cgo) <sub> X </ Sub> (scandia Stabilized Zirconia) <sub> 1-x </ Sub> Synthesis And Characterization,

Solid oxide fuel cell (SOFC) is a high efficient and clean energy conversion device, which converting the chemical energy of fuels and oxidants directly into electrical energy without combustion. It is then regarded as the green power source for the 21^st century. Electrolyte is one of the key materials for SOFC, influencing the performance of the cell system. The synthesis,microstructure,morphology and processing factors are of significant to improve the efficiency of SOFC.The thesis focuses on the processing of Gd₂O₃ doped CeO₂ (CGO),SC₂O₃ stabilized ZrO₂ (ScSZ) , and composite electrolyte (CGO)_x(ScSZ)_1-x.Oxalate co-precipitation method was employed to prepare ultra-fine CGO powders. The properties of the powders, including the phase composition, morphology, as well as sintering ability were characterized. Ultra-fine (40.7nm) and stable CGO powders can be synthesized at pH of 7 and calcination at 850℃for 2h.ScSZ powders were prepared by co-precipitation process. The properties of the powders, including the phase composition, morphology as well as sintering ability were characterized. ScSZ powders with high crystallinity and uniform size (20-30nm) were synthesized of pH above 9 and calcination at 850℃for 2h.The composite electrolyte (CGO)_x(ScSZ)_1-x were prepared by means of ball milling of CGO and ScSZ powders for 2h. In addition to the influence of composition x and temperature, the phase composition and morphology of the powders were studied. At room temperature, there was no chemical reaction between CGO and ScSZ after ball milling. While sintering at 1400℃for 2h, we got solid solution. The variation of lattice parameter (a) with composition x is linear as a = 5.078(3) + 0.344(0)x. With the increase of composition x, there was slightly increase of the interplanar distance and decease in diffraction angle.