The work has started with a thorough study of tbe bibliography on the metal hydrides application as hydrogen storage materials in solid gas process. This study has made possible to determine two families of intermetallic compounds able to reach the needs of the specific application: the AB5-type compounds with MmNi5-xSnx compositions (Mm stands for mischmetal, a mixture of La, Ce, Nd and Pr) as well as tbe AB2-type compounds with Zr1-pTipMn2-r-sNirVs

In the frame of the development of a hydrogen production and storage unit to supply a 40 kW stationary fuel cell, a metal hydride storage tank was chosen according to its reliability and high energetic efficiency. For this purpose, theAB5-type system MmNi5-xSnx (Mm stands for mischmetal) has been investigated. Hydrogen absorption and desorption plateau pressures were adapted to the working range by adjusting the tin content. The structural and thermodynamic

The diffraction peak broadening induced by hydrogen absorption–desorption cycling has been analyzed in four different Laves phase compounds with the C14 and C15 structures. The broadening is due to strain most probably originating from dislocations generated at the interface between the a and b hydride phases in connection with the cell volume difference between the two phases. It has been shown that it is strongly compound dependent. In the case