One-step synthesis of composite electrolytes of Eu-doped ceria and alkali metal carbonates

Abstract

Europium-doped ceria (EDC, Ce0.9Eu0.1O2-delta)/alkaline carbonate (LNC, (Li,Na)(2)CO3) composite ceramics prepared through a one-step citrate-based route were analyzed by powder X-ray diffraction, infrared and laser Raman spectroscopies as well as scanning and transmission electron microscopy. The electrochemical behavior of the electrolyte material was studied by impedance spectroscopy in air, CO2 and N-2 + H-2 (90/10 vol%, respectively) gas mixtures, in the temperature range 300-600 degrees C. The sub micrometric and even nanosized ceramic particles appeared as merged inside the mixed carbonates, with modest grain to grain necking. The EDC/LNC composite electrolytes showed a conductivity of 0.27 S cm(-1) at 600 degrees C in air, amongst the best ever reported, exceeding the usual requirements for fuel cell applications. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.