Berlin 2008 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 39: SYM Hydrogen in Materials: New Developments III
MM 39.2: Hauptvortrag
Donnerstag, 28. Februar 2008, 14:30–15:00, H 1058
Hydrogen Storage in Light Weight Metal Hydrides: Mg-based Reactive Hydride Composites — •M. Dornheim, U. Bösenberg, C. Pistidda, G. Barkhordarian, J. Bellosta v. Colbe, and R. Bormann — GKSS-Research Centre Geesthacht, Institute of Materials Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany
Compared to conventional room temperature hydrides light weight metal hydrides have much higher gravimetric hydrogen storage densities. However, kinetic and/or thermodynamic restrictions limit the potential use of such high capacity hydrides.
There is still a large number of hydrides with high storage capacities which have to be considered as irreversible or at least require high pressures and/or very high temperatures for reversible hydrogenation / dehydrogenation as well as very long absorption and desorption times. Prominent examples are borohydrides like LiBH4.
Another crucial parameter is the reaction enthalpy. Most of the past attempts to alter and tailor the hydrogen reaction enthalpy of light weight metal hydrides like Mg either failed or led to dramatically reduced gravimetric hydrogen storage capacities.
An exciting and promising novel approach is the concept of the Reactive Hydride Composites (RHC). RHC consisting of MgH2 and borohydrides show significantly reduced total reaction enthalpies as well as improved ab- and desorption kinetics compared to the pure borohydrides while a high hydrogen storage capacity is maintained [1].
In this talk, an overview on the sorption behaviour of the doped nanocrystalline RHCs 2LiBH4+MgH2, 2NaBH4+MgH2 and Ca(BH4)2+MgH2 will be given.
Scripta Materialia 56 (2007) 841-846.