Evaluation of Fe-doped CGO electrolyte for application in IT-SOFCs

Abstract

A challenge encountered with intermediate temperature solid oxide fuel cells (IT-SOFCs) is lowering the densification temperature of the doped ceria electrolyte and improving its ionic conductivity. Ceria doped with 10 mol% gadolinium oxide and 0, 1, 5 mol% iron oxide were synthesized by a low temperature precipitation route based on hexamethylenetetramine as the precipitating agent. The as-synthesized precursors are nanocrystalline powders with a homogeneous morphology. Co-doping with Fe3+ changes the sintering behaviour of the doped cerium oxide and favours densification at lower temperatures. Through a comprehensive elementary, structural, microstructural and electrochemical analysis of the co-doped cerium oxide, it was established the doping mechanism of Fe3+ and its effect on the bulk and grain boundary conductivities. The overall aim is to evaluate its suitability for application as an electrolyte in IT-SOFC applications.