Oxygen exchange and transport in dual phase ceramic composite electrodes

John William Richard Druce, Helena Tellez Lozano, Tatsumi Ishihara, John A. Kilner

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

Composites consisting of a perovskite-based electronic or mixed conductor with a fluorite-structured ionic conductor are often used as electrodes in solid oxide electrochemical energy conversion devices. After sintering the materials, there is often evidence for inter-reaction between the two phases, or inter-diffusion of cations or impurities between the two phases. We studied the 18O exchange properties of a composite consisting of CGO and LSCF in a 50 : 50 ratio. High resolution ToF-SIMS mapping reveals that the 18O fraction at the very outer surface of grains of the CGO phase is much higher than expected from D∗ and k∗ values for the single-phase parent material. Surface compositional analysis by ToF-SIMS and low energy ion scattering (LEIS) spectroscopy suggests that the surfaces of the CGO grains in the composite do not show the impurities which typically segregate to the surface in single-phase CGO. Thus, the "cleaning" of impurities from the CGO surface by dissolution into the perovskite phase may be one explanation for the apparent enhanced surface exchange for CGO in these composites.

Original languageEnglish
Pages (from-to)271-288
Number of pages18
JournalFaraday Discussions
Volume182
DOIs
Publication statusPublished - Jan 1 2015

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Ceramics
Electrodes
ceramics
Oxygen
composite materials
electrodes
Composite materials
oxygen
Oxides
Cations
Impurities
Spectrum Analysis
Secondary ion mass spectrometry
Ions
Equipment and Supplies
impurities
secondary ion mass spectrometry
conductors
Fluorspar
Surface analysis

All Science Journal Classification (ASJC) codes

  • Medicine(all)
  • Physical and Theoretical Chemistry

Cite this

Oxygen exchange and transport in dual phase ceramic composite electrodes. / Druce, John William Richard; Tellez Lozano, Helena; Ishihara, Tatsumi; Kilner, John A.

In: Faraday Discussions, Vol. 182, 01.01.2015, p. 271-288.

Research output: Contribution to journalArticle

Druce, John William Richard ; Tellez Lozano, Helena ; Ishihara, Tatsumi ; Kilner, John A. / Oxygen exchange and transport in dual phase ceramic composite electrodes. In: Faraday Discussions. 2015 ; Vol. 182. pp. 271-288.
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