Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 5: Topical Session Interface Dominated Phenomena - Poster
MM 5.6: Poster
Dienstag, 28. September 2021, 10:00–12:45, P
High hydrogen mobility in an amide-borohydride compound studied by quasielastic neutron scattering — •Neslihan Aslan1, Sebastian Busch1, Wiebke Lohstroh2, Claudio Pistidda3, and Martin Müller1,4 — 1German Engineering Materials Science Centre (GEMS) at Heinz Maier-Leibnitz Zentrum (MLZ), Helmholtz-Zentrum Hereon, Garching, Germany — 2Heinz Maier-Leibnitz Zentrum (MLZ), Technical University Munich (TUM), Garching, Germany — 3Institute of Hydrogen Technology, Helmholtz-Zentrum Hereon, Geesthacht, Germany — 4Institute of Materials Physics, Helmholtz-Zentrum Hereon, Geesthacht, Germany
The hydrogen storage performance of reactive hydride composites Mg(NH2)2 + 2 LiH can be significantly improved by the addition of LiBH4 and the subsequent formation of the amide-borohydride compound Li4(BH4)(NH2)3 during hydrogen release. To understand the chemical behaviour and atomic motions of Li4(BH4)(NH2)3, we present an in situ phase analysis with X-ray synchrotron diffraction and quasielastic neutron scattering (QENS) during heating.
Li4(BH4)(NH2)3 melts at 494 K and the crystallization of a second phase is detected and identified as LiNH2. In molten phase, the neutron measurements confirm a long-range diffusive motion of hydrogen-containing species with the diffusion coefficient D ∼ 10−6 cm2/s. In solid phase, localized rotational motions are observed that have been attributed to (BH4)- tetrahedra units mainly undergoing rotations around C3 axes.