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Title: Intermediate Phases Observed During Decomposition of LiBH4

Abstract

Lithium tetrahydridoboranate is among the materials with the highest hydrogen content and has great potential as a possible H2-storage material, although, the release and uptake of H2 is not fully understood. In this work, LiBH4 was studied by in situ synchrotron radiation powder X-ray diffraction (PXD) and solid state CP/MAS NMR both at variable temperatures. This study revealed two new phases observed during dehydrogenation of LiBH4. Phase I is hexagonal, a = 4.93(2) and c = 13.47(3) Angstroms and is observed in the temperature range {approx}200-300 C, and phase II is orthorhombic, a = 8.70(1), b = 5.44(1) and c = 4.441(8) Angstroms and is observed in the temperature range {approx}300-400 C applying a constant heating rate of 5 C/min. Apparently, I transforms into II, e.g. at a constant temperature of T = 265 C after 5 h. Furthermore, a third phase, III, is observed in the temperature range RT to 70 C, and is caused by a reaction between LiBH4 and water vapor from the atmosphere. Hydrogen release is associated with the decomposition of III at ca. 65 C.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Brookhaven National Laboratory (BNL) National Synchrotron Light Source
Sponsoring Org.:
Doe - Office Of Science
OSTI Identifier:
959684
Report Number(s):
BNL-82670-2009-JA
Journal ID: ISSN 0925-8388; JALCEU; TRN: US1005778
DOE Contract Number:
DE-AC02-98CH10886
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Alloys and Compounds; Journal Volume: 446-447
Country of Publication:
United States
Language:
English
Subject:
08 HYDROGEN; 43 PARTICLE ACCELERATORS; DEHYDROGENATION; HEATING RATE; HYDROGEN; LITHIUM; SYNCHROTRON RADIATION; WATER VAPOR; X-RAY DIFFRACTION; national synchrotron light source

Citation Formats

Mosegaard,L., Moller, B., Jorgensen, J., Bosenberg, U., Dornheim, M., Hanson, J., Cerenius, Y., Walker, G., Jakobsen, H., and et al. Intermediate Phases Observed During Decomposition of LiBH4. United States: N. p., 2007. Web. doi:10.1016/j.jallcom.2007.03.057.
Mosegaard,L., Moller, B., Jorgensen, J., Bosenberg, U., Dornheim, M., Hanson, J., Cerenius, Y., Walker, G., Jakobsen, H., & et al. Intermediate Phases Observed During Decomposition of LiBH4. United States. doi:10.1016/j.jallcom.2007.03.057.
Mosegaard,L., Moller, B., Jorgensen, J., Bosenberg, U., Dornheim, M., Hanson, J., Cerenius, Y., Walker, G., Jakobsen, H., and et al. Mon . "Intermediate Phases Observed During Decomposition of LiBH4". United States. doi:10.1016/j.jallcom.2007.03.057.
@article{osti_959684,
title = {Intermediate Phases Observed During Decomposition of LiBH4},
author = {Mosegaard,L. and Moller, B. and Jorgensen, J. and Bosenberg, U. and Dornheim, M. and Hanson, J. and Cerenius, Y. and Walker, G. and Jakobsen, H. and et al},
abstractNote = {Lithium tetrahydridoboranate is among the materials with the highest hydrogen content and has great potential as a possible H2-storage material, although, the release and uptake of H2 is not fully understood. In this work, LiBH4 was studied by in situ synchrotron radiation powder X-ray diffraction (PXD) and solid state CP/MAS NMR both at variable temperatures. This study revealed two new phases observed during dehydrogenation of LiBH4. Phase I is hexagonal, a = 4.93(2) and c = 13.47(3) Angstroms and is observed in the temperature range {approx}200-300 C, and phase II is orthorhombic, a = 8.70(1), b = 5.44(1) and c = 4.441(8) Angstroms and is observed in the temperature range {approx}300-400 C applying a constant heating rate of 5 C/min. Apparently, I transforms into II, e.g. at a constant temperature of T = 265 C after 5 h. Furthermore, a third phase, III, is observed in the temperature range RT to 70 C, and is caused by a reaction between LiBH4 and water vapor from the atmosphere. Hydrogen release is associated with the decomposition of III at ca. 65 C.},
doi = {10.1016/j.jallcom.2007.03.057},
journal = {Journal of Alloys and Compounds},
number = ,
volume = 446-447,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
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