"New developments in solid state hydrogen storage"
Relatore: Chiara Milanese- Pavia H2 Lab, Dipartimento di Chimica, Università di Pavia
Note: Seminario di Dipartimento
20 Novembre 2013 ore 16.30
|Hydrogen is a very promising energy carrier for a comprehensive clean energy concept in mobile and stationary applications. For on-board hydrogen storage, gravimetric and volumetric capacities as well as fast sorption kinetics still belong to some of the main challenges. Conventional
hydrogen storage methods such as high pressure gas or liquid hydrogen cannot fulfil the set future storage goals. Storage in solid state seems the safest and most promising way to reach the target. Many materials and composites have been explored in the last decade concerning their chemico-physical and hydrogen sorption properties, by using conventional and unconventional experimental techniques. In particular, MgH2 – based materials and C-based materials have been attracting interest. MgH2 is one of the most promising materials for hydrogen storage, due to its high gravimetric capacity and the good reversibility of the sorption reactions. However, its high dehydrogenation
enthalpy limits its practical use. One of the possibilities to decrease the enthalpy is mixing MgH2 with metals or metals oxides with catalysing and destabilising activities. In this frame, the Pavia Hydrogen Lab undertook a comprehensive study on the possible activities of transition metals and at the end realised a prototype composed of an electrolyser for hydrogen production, a Mg-based solid state tank (containing the fully innovative Mg-Mg2Ni-C-TiO2 quaternary composite) for the storage and a 1kW fuel cell for energy production. A second possibility to decrease MgH2 desorption enthalpy is to combine this hydride with light-metal hydrides in the so called Reactive Hydride Composite (RHC) strategy. Among RHCs, the Pavia H2 Lab focussed on the LiBH4 – MgH2 and NaBH4 – MgH2
systems. The optimization of the sorption characteristics of the first one allowed the realization of the first solid state tank based on RHC. Concerning the C-based materials, attention has been recently focused on fullerene and
graphene derivatives. The Pavia Hydrogen Lab is collaborating with the Carbon Nanostructures Lab of the Parma University in the characterization of fullerene derivatives with storage performance similar to the ones of the Mg-based materials. All the recent results on these topics will be described in this talk, together with a short
overview on the conventional and unconventional characterization methods for the solid state hydrogen storage materials.