Structural and Electrical Properties of Gadolinia-doped Ceria Mixed with Alkali Earth Carbonates for SOFC Applications

Abstract

The properties of composite materials based on mixtures of gadolinium-doped ceria (GDC) and Li2CO3-K2CO3 are analyzed as potential SOFC electrolytes. In a temperature range higher than 500{degree sign}C, their ionic conductivity is significantly higher than for single GDC. Discontinuities were found in the conductivity Arrhenius diagram (σ vs. 1/T) around the melting point of the carbonate mixture (490{degree sign}C), showing, at least partially, the contribution of molten carbonates. At this stage, precise mechanisms are still under analysis.