Preparation and hydrogen storage properties of Mg-Ni-Mg2Ni laminate composites

A new method for producing laminated Mg-Ni binary hydrogen storage materials has been developed. This method is repetition of alternate stacking and cold rolling, combined with final heat treatment. Characterization of as-rolled specimens by SEM and SEM-EDS revealed that repetitive rolling results in a dispersion of fractured Ni grain in Mg matrix and the edge of Ni grains were gradually deformed. Characterization of heat-treated samples by SEM, EDS, XRD and hydrogen absorption-desorption test by Sieverts' apparatus also revealed that interdiffusion between Mg and Ni by heat treatment resulted in the formation of intermetallic compound Mg2Ni at the interface. Especially in the case of Mg/Ni = 2, single phase Mg2Ni was obtained, and the sample was hydrogenated to Mg2NiH4 completely.