Proton trapping in yttrium-doped barium zirconate

Yoshihiro Yamazaki, Frédéric Blanc, Yuji Okuyama, Lucienne Buannic, Juan C. Lucio-Vega, Clare P. Grey, Sossina M. Haile

Research output: Contribution to journalArticlepeer-review

205 Citations (Scopus)

Abstract

The environmental benefits of fuel cells have been increasingly appreciated in recent years. Among candidate electrolytes for solid-oxide fuel cells, yttrium-doped barium zirconate has garnered attention because of its high proton conductivity, particularly in the intermediate-temperature region targeted for cost-effective solid-oxide fuel cell operation, and its excellent chemical stability. However, fundamental questions surrounding the defect chemistry and macroscopic proton transport mechanism of this material remain, especially in regard to the possible role of proton trapping. Here we show, through a combined thermogravimetric and a.c. impedance study, that macroscopic proton transport in yttrium-doped barium zirconate is limited by proton-dopant association (proton trapping). Protons must overcome the association energy, 29 kJ mol -1, as well as the general activation energy, 16 kJ mol -1, to achieve long-range transport. Proton nuclear magnetic resonance studies show the presence of two types of proton environment above room temperature, reflecting differences in proton-dopant configurations. This insight motivates efforts to identify suitable alternative dopants with reduced association energies as a route to higher conductivities.

Original languageEnglish
Pages (from-to)647-651
Number of pages5
JournalNature Materials
Volume12
Issue number7
DOIs
Publication statusPublished - Jul 2013
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Proton trapping in yttrium-doped barium zirconate'. Together they form a unique fingerprint.

Cite this