Sprecher
Beschreibung
The hydrogen storage in light-weight hydrides for mobile applications is an extensively discussed but a rather controversial topic. Is it safe enough? Is it efficient enough? Does the hydrogen energy have future? The questions are numerous and complicated and hardly any of them has a definite answer yet. A complex hydride system 6Mg(NH2)2:9LiH with LiBH4 as a dopant is one of promising candidates on a role of on-board hydrogen storage, since it it actively decomposes with hydrogen-only emission already at the 180oC. The role of the LiBH4 is expressed in forming of an low-melting liquid-phase with high hydrogen mobility with an intermediate product LiNH2, which highly enhances the rate of the dehydrogenation reaction. There are 2 mixed phases with a high Li-ion conductivity described: a metastable Li2BH4NH2 and a peritectically melting Li4BH4(NH2)3, and both of these phases were registered while performing DSC and XRD measurements. This 2-component system is investigated and a number of ratios was analyzed and thereupon a phase diagram was plotted. Its lowest melting point, i.e. eutectic point is located at 33% LiNH2 and at 90oC. The behavior under heating and the intrinsic structure of this eutectic composition was investigated by neutron total scattering. The composition corresponding to this eutectic mixture would be 6Mg(NH2)2:9LiH:6LiBH4.
