This project is collaboration between Institute for Energy Technology (Dep. of Energy Systems and Dep. of Physics) and NTNU (Dep. of Materials Science and Engineering).
The project aims at significant improvement of the energy density characteristics and operating time of the Rechargeable Metal Hydride Batteries by development and use of the novel metal hydride materials with superior electrochemical performance. New Mg-based materials for energy storage will be in focus, as anode materials in rechargeabl e batteries and, also, as hydrogen storage materials.
Two classes of materials will be considered: Mg-substituted alloys based on AB3 and A2B7 hydrogen absorbing alloys and Mg-rich MgyTM1-y alloys (TM= transition metal) with y = 0.6-0.9. The former class is already proven effective as anode materials in RMHB. However, the fundamental properties and their dependence on the Mg-content are poorly understood and the work will be done to establish efficient synthesis routes for the optimized compounds and to p repare electrodes with superior energy density characteristics. The latter class is not yet considered for battery applications, mainly due to difficulties in the synthesis. Mg-rich, ordered phases of the type Mg6-7TMH~14 have been prepared in small amoun t under high pressure. Rutile-type MgyTM1-y alloys often require non-equilibrium synthesis techniques. They will both be synthesized in the present project with ball milling techniques which have proven effective for production of metastable phases. The m aterials will be systematically synthesized and their crystal structures, microstructures, thermodynamics, kinetics, corrosion behaviour and cycling stability will be investigated with X-ray and neutron diffraction, SEM, TEM, DSC, TPD, Sievert's technique and electrochemical techniques. Especially promising hydrides will be assembled into the MH anode electrodes and integrated into the prototype batteries. The project will train two postdocs.