Prof. Abdelilah Benyoussef
Faculty of Science,
Mohammed V University
Rabat, Morocco
Magnesium is one of the most attractive materials for hydrogen storage applications, due to its high gravimetric and volumetric capacities (7.65 wt.% and 110 gH2/l, respectively) in the form of stoichiometric binary MgH2 [1]. However, its slow hydrogen absorption and desorption kinetics, as well as the high dissociation temperature of 573–673 K, essentially limit its application for hydrogen storage. In this talk Electronic structural studies of Mg-based alloy hydrides will be presented to show further modifications that could destabilize the corresponding hydrides by lowering the desorption temperature and enhance the hydrogen kinetics characteristics [2]. We propose a model to investigate the hydrogen storage ab/desorption kinetic properties for the pure and doped MgH2 using Kinetic Monte Carlo (KMC) simulations. To do such computations, the activation energies for different elementary processes have been estimated. Moreover, the different thermodynamical quantities of interest are determined by performing the ab-initio calculations. Then, we discuss the hydrogen diffusion in magnesium hydride (such as adsorption, diffusion and desorption). More precisely, we study the effect of each elementary mechanism on the diffusion that we characterize through the density distribution of hydrogen atoms including filling ratios, diffusion time, temperature and pressure [3, 4]. Thus, we show that the energy barriers of MgH2 when doped with a small amount of different metals,(Al, Ti, V, Fe and Ni) decrease considerably leading to a decreasing of both the stability and the desorption temperature and lowering considerably the ab/desorption time without reducing significantly the storage capacity of the material [4].
[1] Cabo M, Garrroni S, Pellicer E, Milanese C, Girella A, Marini A, Rossinyol E, Surinach S and Dolors Baro M 2011 International Journal of Hydrogen Energy 36 5400
[2] M. Bhihi, M. Lakhal, H. Labrim, A. Benyoussef, A. El Kenz, O. Mounkachi, and E. K. Hlil, Chin. Phys. B Vol. 21, No. 9 (2012) 097501
[3] M. Lakhal, M. Bhihi, H. Labrim, A. Benyoussef , S. Naji, A. Belhaj, B. Khalil, M. Abdellaoui, O. Mounkachi, M. Loulidi, A. El kenz, International Journal of Hydrogen energy 3 8 ( 2013) 8350-8356
[4] M. Lakhal, M. Bhihi, A. Benyoussef, A. El Kenz, M. Loulidi, S. Naji, International Journal of Hydrogen energy 4 0 ( 2015) 6137-6144
Biography
Abdelilah Benyoussef received his “Doctorat d’état” degree from the Paris-Sud University in 1983. He is a permanent member of the Moroccan Hassan II Academy of Science and Technology, since 2006. He is associate professor in the materials and nanomaterials center of the Moroccan Foundation for Advanced Science, Innovation and Research. He is National coordinator of the Competences Pole of Condensed Matter and Systems Modeling. He is also an editor in chief of the Moroccan Journal of Condensed Matter. He is President of the Moroccan Society of Statistical Physics and Condensed Matter. He has been visiting professor in many research centers, laboratories and Universities in Belgium, Canada, Egypt, France, Germany, Japan, Spain, Tunisia, and United states. The main interest topics of Abdelilah Benyoussef are Ab initio calculation and Monte carlo method in modeling and simulation of new materials for renewable energy; Magnetism and phase transition in condensed matter; complex systems and critical self organization in statistical physics.