At present there is no solid state hydrogen storage material available fulfilling all requirements for practical use in mobile applications. These are 1. high storage density, 2. temperatures and heats of operation compatible with PEM fuel cells, 3. high hydrogen loading and unloading speeds in the range of a few minutes and 4. low production costs. FlyHy focuses especially on the first three points while using commercially upscalable materials preparation processes. High hydrogen capacity materials like alane or borohydrides as well as so called Reactive Hydride Composites (mixtures of borohydrides with selected other hydrides), nowadays suffering from too high or too low reaction temperatures and heats, shall be modified by substituting halogens for part of the hydrogen or hydrogen containing complexes. The project partners IFE, GKSS and AU have shown that by this approach novel mixed hydrido-halogenide compounds can be prepared. Fluorine substituted Sodium Alanate exhibited drastically increased desorption pressures at the same reaction temperature or lowered reaction temperatures at the same pressure resp. Targets of the FlyHy project are (i) to exploit these findings on materials destabilisation and stabilisation resp. by halogen substitution for alane, borohydrides and Reactive Hydride Composites , in order to achieve a breakthrough in the thermodynamic properties of these materials exhibiting the highest hydrogen capacities known at present, (ii) to obtain an in depth scientific understanding of the sorption properties of the substituted materials by extended structural and thermodynamical characterisation and modelling, for materials optimisation, (iii) determine tank relevant materials properties like e.g. densification behaviour and heat conductivity, and, if applicable, do first tests in a prototype tank.