Ionic diffusion and structural changes in lithium compounds

Koichi Nakamura, Hiroshi Hirano, Daisuke Nishioka, Shigeki Endou, Kazuya Itsuki, Yoshitaka Michihiro, Toshihiro Moriga, Naoaki Kuwata, Junichi Kawamura

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

7Li NMR measurements have been performed to study milling effects on ionic diffusion in lithium cobalt oxide, LiCoO2 and piezoelectric compound, LiNbO3 prepared by mechanical milling method. The milling process gives quite different effects on NMR spectra of these compounds. Both 7Li MAS and static NMR spectra of the milled LiCoO2 show the line broadening with increasing milling time. 59Co static spectra also show specific changes in the line shape with increasing milling time. These results would be attributed to the change in an electronic state of Co 3d orbitals because of charge compensation associated with oxygen vacancies and/or defects. 7Li static NMR spectrum of milled LiNbO3 shows complicated line shape with increasing milling time. It is explained by superposition of two spectra arising from mobile Li+ ions and non-mobile ones settled on the fixed site. It is shown that the ratio of mobile Li+ ions increases up to a maximum of 9.4% with increasing milling time. Milling effects on the Li+ ionic diffusion in LiCoO2 and LiNbO3 are discussed in connection with changes in local structure.

Original languageEnglish
Pages (from-to)621-625
Number of pages5
JournalSolid State Ionics
Volume180
Issue number6-8
DOIs
Publication statusPublished - 2009 May 14

Keywords

  • LiCoO
  • LiNbO
  • Lithium ionic diffusion
  • Mechanical milling
  • NMR

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

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