Quantifying multi-ionic conduction through doped ceria-carbonate composite electrolyte by a current-interruption technique and product analysis

A composite electrolyte consisting of a samarium doped ceria and a binary eutectic carbonate phase is investigated in this work. It has been found that O2-/H+ conductions take place when H-2 and O-2 used as the reactants. The presence of CO2 in the cathode gas leads to the appearance of CO32- conduction. The overall conductivity of the composite electrolyte is measured with a current-interruption technique and the ions transferred by O2-/H+/CO32- respectively are obtained by a quantitative measurement of the reaction products, i.e. H2O and CO2. The change of the carbonate content in the composite electrolyte presents a great influence on the conductivity of each ion. According to these experimental facts, the pathways for the individual ionic conductions are proposed. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.