Contatto di riferimento: Laura Basiricò
Partecipanti: Prof. Marina Sheylapina: SPbU Saint Petersburg State University
Hydrogen storage is a key point for the extensive use of hydrogen as an energy carrier. The
safest way to store hydrogen is in solid metal hydrides, from which it can be recovered by
heating. To be economically feasible the metal or alloy used for hydrogen storage has to
exhibit high hydrogen storage capacity, low temperature of the hydrogen release and be
low cost. Unfortunately among many metals and alloys reacting with hydrogen there is no
such a material that meets all the necessary criteria.
Despite low hydrogen sorption kinetics and high stability magnesium is one of the mos
perspective materials for hydrogen storage. Numerous attempts have been made in orde
to improve its hydrogen absorbing-desorbing characteristics by alloying with transition
metals and their alloys, such as Ti-V-Cr, micro- and nanostructuring and so on. But the
fundamental issues of the impact, sometimes rather dramatic, of such modifications of Mg
on its stability and hydrogen sorption kinetics are not completely understood.
Density functional theory (DFT) is a powerful and valuable tool to study metal hydrogen
systems. It provides both a fundamental insight to the electronic and thermodynamic
properties of metal-hydrogen systems and guidance in searching for new hydrogen
storage materials.
Here we provide a brief overview of recent DFT studies of metal-hydrogen systems fo
hydrogen storage. We will focus on MgH2, both pure and doped with transition metals
and hydrides of disordered Ti-V-Cr alloys to discuss such properties as metal-hydrogen
bonding, phase stability, phase transformations and hydrogen diffusion. The results o
theoretical studies of hydrogen diffusivity in metal lattice will be compared with
experimental nuclear magnetic resonance (NMR) data.