Identification of phase in-homogeneities in Na-SrSiO3 electrolytes for low temperature SOFCs

Abstract

In this work we have synthesized and characterized sodium doped SrSiO3 electrolyte, for use in low and intermediate temperature solid oxide fuel cells (SOFCs). Great interest was placed onto this material after its first report in 2012, which was later dampened by conflicting reports about the properties of this class of materials. It is imperative to resolve this issue from the viewpoint of development of low and intermediate temperature SOFCs. Here, we report the most comprehensive data till date on the properties of this class of materials. Although it is desired to synthesize a single phase material, strong evidences presented here suggest that it is a multiphase material. The reason for obtaining a multiphase material is discussed considering the reaction thermodynamics. Additional data presented here establish that at the operating temperature (~750 °C) of SOFC devices, amorphous phases in the material transforms into a crystalline phase.