Alanate-borohydride material systems for hydrogen storage applications
Abstract
Alteration of the thermodynamic stability of selected borohydride/alanate systems, including the combination of LiBH_4 with NaAlH_4 and LiBH_4 with CaCl_2 and LiAlH_4, was investigated to determine the possibility of forming intermediate stability mixed AlH_(4)^(−)–BH_(4)^(−) phase. Facile metathesis exchange reactions were observed when NaAlH_4 was combined with LiBH_4 resulting in the formation of LiAlH_4 and NaBH_4. Thermal analysis of this system showed that the 1st and 2nd decomposition of LiAlH_4 occurred irrespective of NaBH_4 illustrating the absence molecular level interaction between the AlH_(4)^(−) and the BH_(4)^(−) anions. On the other hand, in the case of CaCl_2, LiAlH_4, LiBH_4 combination, the results showed the formation of a calcium alanate type phase. Evaluation of the thermal property of this system showed an endothermic one step decomposition between 130 °C and 200 °C (2.3 wt% loss). Structural examination of this calcium alanate type phase revealed a different local coordination geometry of AlH_(4)^(−) from that observed in calcium alanate. The formation and properties of this phase are being attributed to molecular level AlH_(4)^(−)–BH_(4)^(−) interactions. These findings provide a pathway toward designing novel alanates-borohydrides systems for hydrogen storage applications. This article will show the methodologies followed and explain the results obtained.
Additional Information
© 2011 Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. Received 1 September 2011. Revised 12 October 2011. Accepted 15 October 2011. Available online 25 November 2011. The authors would like to thank Dr. Hanno Zur Loye at the Department of Chemistry and Biochemistry, University of South Carolina, for conducting the X-ray diffraction experiments and for the helpful discussions. Also, the authors would like to thank Dr. Ted Motyka at Savannah River National Laboratory for managing the research project and for his helpful insight. Finally, many thanks for Dr. Jason Graetz at Brookhaven National Laboratory for providing the Dow alane sample. Funding for the work was provided by Toyota Motor Engineering and Manufacturing North America. The NMR facility at Caltech was supported by the National Science Foundation (NSF) under Grant Number 9724240 and partially supported by the MRSEC Program of the NSF under Award Number DMR-520565.Additional details
- Eprint ID
- 30038
- DOI
- 10.1016/j.ijhydene.2011.10.076
- Resolver ID
- CaltechAUTHORS:20120409-112817839
- Toyota Motor Engineering and Manufacturing North America
- DMR-9724240
- NSF
- DMR-520565
- NSF
- Created
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2012-04-09Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field