Marie Curie ITN ECOSTORE - "Novel Complex Metal Hydrides for Efficient and Compact Storage of Renewable Energy as Hydrogen and Electricity" (2013 - 2017)
The transition towards a sustainable, carbon-free and reliable energy system capable of meeting the increasing energy demand is considered one of the greatest challenges of the 21st century, as expressed e.g. by the 20/20/20 initiative of the European Commission. The alternative to fossil fuels and nuclear power (recall the Fukushima accident 2011 in Japan) are renewable energy sources like solar, wind, and wave energy. However, these sources are unevenly distributed both in location and time, which call for development of advanced energy storage systems with high capacity and efficiency. The most promising approaches are based on direct storage of electricity in batteries and storage of hydrogen produced by electrolysis, based on advanced materials, as supported by a recent European Commission’s report and the EERA Joint Program “Energy Storage”. Joint research and training on materials and systems for both approaches are the exact focus of the ECOSTORE Initial Training Network.
Metal hydrides, the scientific focus of ECOSTORE, are of special interest for both: obviously for hydrogen storage, but – as recently found - also for electrochemical energy storage as novel solid state ion conductors and anode conversion materials. They exhibit superior hydrogen and electrochemical energy storage capacities as well as high ionic conductivities at ambient temperatures. For further development of these highly promising materials, but also for transfer to industrial production and use in energy storage applications, well trained experts are needed, who not only have an in-depth knowledge of materials and characterisation techniques, but who also have an understanding of the production technologies and potential applications of these materials for all fields of energy storage technologies.
Borohydride- and nitride-based materials exhibit very high hydrogen storage capacities up to 18 wt%, and they also show excellent properties as novel solid room temperature ion conductors or negative electrode materials with improved capacity, thus allowing for very high energy storage densities. For commercial use a prerequisite is the cost efficient large scale production from abundant and relatively cheap raw materials combined with scale-up-ability, and to demonstrate the techno-economical readiness on the prototype scale. The objectives of ECOSTORE are therefore to obtain a fundamental understanding of metal hydride based energy storage materials, and to develop them towards industrial implementation, achieving high technical performance as well as cost effectiveness. Detailed fundamental studies in close collaboration with those for hydrogen and those for electrochemical energy storage, including use of more cost efficient raw materialswill enable ECOSTORE to go beyond the state-of-the-art and reach its targets on energy storage materials:
- Development of (i) novel bi- and tri-metal borohydrides, complex nitrogen based hydrides, their combinations and Reactive Hydride Composites with high hydrogen densities, low decomposition temperatures, high ion conductivities at low temperatures, and high electrochemical capacities, respectively, (ii) techniques for stabilisation of high temperature phases towards room temperature, exhibiting enhanced diffusion speeds for ions and other mobile active species, (iii) improved kinetics and thermodynamics of release and uptake of hydrogen or ions, respectively, and cycling stability using suitable additives and/or nanoconfinement for reduced phase separation and crystal growth during hydrogenation, (iv) improved safety of materials by nanoconfinement, (vi) facilitated hydrogenation by functionalised scaffolds containing catalytic nanoparticles.
- Theoretical modelling supported by advanced in situ and nanoscale characterisation, to obtain a full understanding of the materials structural, physical and chemical properties.
- Cost reduction by utilisation of less pure raw materials, available on a larger industrial scale, while still preserving storage performance of the materials.
- Evaluation of the techno-economical potentials, by studying the cycling and degradation behaviour of most promising materials in a prototype hydrogen storage tank, and in prototype battery cells, respectively.
 “The EU climate and energy package“, http://ec.europa.eu/clima/policies/brief/eu/package_en.htm
 EU Commission staff working pager, “Materials Roadmap Enabling Low Carbon Energy Technologies“, Brussels, 13.12.2011, section 3.5. Electricity storage, section 3.9 Hydrogen and Fuell Cells, http://ec.europa.eu/research/industrial_technologies/pdf/materials-roadmap-elcet-13122011_en.pdf