Ceria (Sm3+, Nd3+)/carbonates composite electrolytes with high electrical conductivity at low temperature

Composite electrolytes composed of Sm3+ and Nd3+ co-doped ceria (SNDC) and binary carbonates (Li2CO3–Na2CO3) were investigated with respect to their microstructure, morphology and electrical conductivity. As a function of temperature, the electrical conductivity of the composite electrolytes was measured in air. The addition of (Li/Na)2CO3 to SNDC enhanced the high temperature conductivity. The conductivity also rose sharply around the intenerating and melting point of carbonates. The best performance of 0.01 S/cm at 481 °C was achieved for the composite electrolyte containing 20 wt.% carbonates. It is also estimated that the reason for the conductivity enhancement of SNDC is that the number of oxygen transfer routes increases at the interface between SNDC and (Li/Na)2CO3.