Effect of CaO concentration on enhancement of grain-boundary conduction in gadolinia-doped ceria

Pyeong Seok Cho, Sung Bo Lee, Yoon Ho Cho, Doh Yeon Kim, Hyun Min Park, Jong Heun Lee

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48 Citations (Scopus)

Abstract

This study examines the effect of calcium oxide (CaO) addition to Ce 0.9Gd0.1O1.95 (gadolinia-doped ceria, GDC) containing 500 ppm SiO2 on grain-interior and grain-boundary conduction. The GDC can be used as a solid electrolyte for intermediate and low-temperature solid oxide fuel cells. Doping with ≥2 mol% CaO results in a decrease in apparent grain-boundary resistivity at 300 °C from 746.7 kΩ cm to 2.8-3.5 kΩ cm. The total resistivity exhibits a minimum at 2 mol% CaO. Further increase in CaO concentration to 10 mol% results in an increase in grain-interior resistivity from 3.1 to 40 kΩ cm. Although most of the CaO is incorporated into the GDC lattice, a small amount of CaO scavenges the intergranular siliceous phase, which leads to a significant increase in grain-boundary conduction. The increase in grain-interior resistivity at high CaO concentration is attributed to defect association between Vo and Cace".

Original languageEnglish
Pages (from-to)518-523
Number of pages6
JournalJournal of Power Sources
Volume183
Issue number2
DOIs
Publication statusPublished - 2008 Sep 1

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Keywords

  • Calcium oxide
  • Gadolinia-doped ceria (GDC)
  • Grain-boundary conduction
  • Scavenging effect
  • Solid oxide fuel cell

ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Energy Engineering and Power Technology
  • Renewable Energy, Sustainability and the Environment
  • Physical and Theoretical Chemistry
  • Energy (miscellaneous)

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