Synthesis and Characterizations of Doped Barium Zirconate – Alkali Carbonate Composite Electrolytes

Abstract Composite materials based on yttrium-doped zirconate (BaZr0.9Y0.1 O2.95, BZY) and eutectic compositions of alkali carbonates (Li2CO3, Na2CO3 and K2CO3) are investigated. These materials were characterized by X-ray diffraction, scanning electron microscopy and impedance spectroscopy. This study evidences that the combination of BZY with carbonate promotes the densification and enhances the ionic conductivity which reaches 87 mS.cm-1 at 400°C for the BZY – LNK40 composite. In addition, the increase of the conductivity as a function of pH2 suggests that protons are the main charge carriers. The obtained results are interpreted by the transfer of protons from the ceramic to the carbonate phase in the interfacial region.