NANO SIZED CERIA SOLID SOLUTIONS FOR INTERMEDIATE TEMPERATURE SOLID OXIDE FUEL CELLS

摘要

The effect of small amounts (<5 cat%) of dopants on the sintering characteristics and electrochemical performance of cerium oxide solid solutions have been evaluated. Ce_(0.8)Gd_(0.2)O_(2-x) powder with an average crystallite size of 20 nm served as model substance for electrolytes with a high oxygen ionic conductivity and low electronic conductivity. Sintering to >99% of the theoretical density has been achieved at temperatures below 900℃ resulting in an average grain size less than 150 nm in the sintered material. AC and DC conductivity measurements at different temperatures revealed that for doping levels below 2 cat% the ionic conductivity remains unchanged compared to the undoped CGO.