Experimental and theoretical study of compositional inhomogeneities in LaNi5Dx owing to temperature gradients and pressure hysteresis, investigated using spatially resolved in-situ neutron diffraction

Pressure cells for in situ neutron total scattering: time and real-space resolution during deuterium absorption

“…The transition process from the deuterium solid-solution phase to the deuteride phase up to an equilibrium pressure of 1.8 MPa at room temperature was investigated every 10 s, but a metastable intermediate phase was not detected (Fig. 4) (Joubert et al, 2006;Gray et al, 2011;Mohammadshahi et al, 2017). The lattice constant of the intermediate phase is close to that of the hydride (Machida et al, 2014) and it is difficult to distinguish between them in neutron diffraction, where the main scattering factor is the diffraction peak of deuterium, whose atomic displacement is larger than that of the metal.…”

Postsynthetic Modification of a Network Polymer of Intrinsic Microporosity and Its Hydrogen Adsorption Properties

“…However, although some of these materials exhibit high capacities, there are practical drawbacks, such as high enthalpies of the formation that subsequently require temperatures over 300 °C [e.g., MgNH 4 and Na + (BH 4 ) − ], poor kinetics for the release of hydrogen (e.g., MgH 2 ), and irreversible dehydrogenation or rehydrogenation reactions (e.g., LiAlH 4 ). , A success story in energy storage has been the development of nickel–metal hydride batteries, demonstrating that it is feasible to store large amounts of hydrogen in intermetallic alloys (archetype LaNi 5 ) providing high intrinsic kinetics and relatively low enthalpies. However, it is worth noting that even this enthalpy constrains the size of the system or requires extensive heat management. − In addition, effective intermetallic alloys are heavy, limiting their application to stationary systems …”