Title:Ab Initio Study of Lithium-Boron and -Aluminum Hydrides Nanoparticles
VOLUME: 1 ISSUE: 2
Author(s):Fotios Michos and Michalis M. Sigalas
Affiliation:Department of Materials Science, University of Patras, GR-26504 Patras, Greece.
Keywords:Hydrogen storage, LiAl and LiB hydrides, density functional theory, nanoparticles, desorption energy, metal hydrides.
Abstract:Background: Hydrogen is considered as the fuel of the future since it has about three times
higher energy per mass relative to gasoline. However, it is difficult to be stored and there is intense effort
to find materials that can store as much as possible hydrogen. Lithium-Aluminium and -Boron hydrides
are some of the most important compounds used in hydrogen storage with promising hydrogen
weight percentages and low desorption energies.
Methods: The Density Functional Theory (DFT) have been used to calculate the desorption energies of
Hydrogen in Lithium-Aluminium, and -Boron nanoparticles.
Results: The type of nanoparticles studied were LinMnHxn with M = Al or B, n varying from 1 up to 20
and x between 0 and 4. Complex nanoparticles LinAln-yByH4n have been also examined. These type of
nanoparticles try to combine the low weight of LinBnH4n with the low desorption energies of LinAlnH4n.
Finally, NanAlnH4n nanoparticles have been studied. For all these cases, several different geometries
were examined and the lowest energy geometry was chosen.
Conclusion: For the fully hydrogenated NPs (x=4), the desorption energy reduces as n increases saturating
to about 135 and 47 kJ/mol for Li20B20H80 and Li20Al20H80, respectively, in close agreement with
measurements.
