Evaluation of the Microstructure and the Electrochemical Properties of Ce(0.8(1-x))Gd(0.2(1-x))Cu(x)O([1.9(1-x)+x])Electrolytes for IT-SOFCs

Abstract

The influence of copper addition (0.5-2 mol%) on the crystal structure, densification microstructure, and electrochemical properties of Ce(0.8)Gd(0.2)O(1.9)synthesized in a one-step sol-gel combustion synthesis route has been studied. It has been found that Cu is very active as sintering aids, with a significative reduction of GDC firing temperature. A reduction of 500 degrees C with a small amount of copper (0.5 mol%) was observed achieving dense bodies with considerable ionic conductivities. Rietveld refined was used to investigate the crystal structure while relative density and microstructural examination were performed in the sintering temperature range of 1000-1200 degrees C after dilatometer analysis. High dense bodies were fabricated at the lowest sintering temperature, which promotes the formation of Ce(0.8(1-x))Gd(0.2(1-x))Cu(x)O([1.9(1-x)+x])solid solution and the absence of secondary phase Cu-rich or the segregation or copper at the grain boundary. As compared to the pure GDC an improvement of total conductivity was achieved with a maximum for the highest copper content of 2.23 center dot 10(-3)-9.19 center dot 10(-2)S cm(-1)in the temperature range of 200-800 degrees C.