Phase Behavior in the LiBH4-LiBr System and Structure of the Anion-Stabilized Fast Ionic, High Temperature Phase

Irene Cascallana-Matias, David A. Keen, Edmund J. Cussen, Duncan H. Gregory

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The fast ionic, high temperature (HT) phase of LiBH4 can be stabilized by Br- substitution. Lithium borohydride bromide compounds, Li(BH4)1-xBrx, have been synthesized mechanochemically, with and without thermal treatment and the resulting phase behavior determined as a function of composition. Single phase materials exist for 0.29 ≤ x ≤ 0.50 with conductivity 2 orders of magnitude higher than LiBH4 at 313 K. Powder neutron diffraction has been used to resolve the details of the crystal structure of one such compound. These demonstrate that 7Li(11BD4)0.667Br0.333 retains the HT structure (hexagonal space group P63mc, a ≈ 4.2 Å, c ≈ 6.7 Å) from 293 to 573 K. The borohydride bromide exhibits considerable static and dynamic disorder, the latter invoking complex rotational motion of the (BH4)- anions.

Original languageEnglish
Pages (from-to)7780-7787
Number of pages8
JournalChemistry of Materials
Volume27
Issue number22
DOIs
Publication statusPublished - Oct 26 2015
Externally publishedYes

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Phase behavior
Bromides
Anions
Negative ions
Borohydrides
Neutron powder diffraction
Lithium
Substitution reactions
Crystal structure
Heat treatment
Temperature
Chemical analysis
lithium borohydride

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

Cite this

Phase Behavior in the LiBH4-LiBr System and Structure of the Anion-Stabilized Fast Ionic, High Temperature Phase. / Cascallana-Matias, Irene; Keen, David A.; Cussen, Edmund J.; Gregory, Duncan H.

In: Chemistry of Materials, Vol. 27, No. 22, 26.10.2015, p. 7780-7787.

Research output: Contribution to journalArticle

Cascallana-Matias, Irene ; Keen, David A. ; Cussen, Edmund J. ; Gregory, Duncan H. / Phase Behavior in the LiBH4-LiBr System and Structure of the Anion-Stabilized Fast Ionic, High Temperature Phase. In: Chemistry of Materials. 2015 ; Vol. 27, No. 22. pp. 7780-7787.
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