Magnesium Films for Hydrogen Storage

Abstract

Metal hydrides are one of the most promising systems for safe hydrogen storage. Among these, magnesium hydride is particularly attractive because of its high hydrogen storage capacity and low cost. Unfortunately, pure magnesium has poor hydrogenation characteristics : slow hydrogen sorption kinetics and high temperature of operation. New materials such as nanocrystalline alloys, materials prepared by plasma techniques and evaporation-condensation have been studied elsewhere in order to circumvent these disadvantages. In the present work, we studied pure magnesium films prepared by vacuum evaporation. The structural and hydrogen sorption properties of magnesium film are presented. Morphology and structural properties were studied by scanning electron microscopy (SEM), X-Ray Diffraction (XRD) and Rutherford Backscattering Spectrometry (RBS). Hydrogen sorption properties were studied using pressure-composition isotherm measurements. Pure magnesium films were found to have better hydrogen sorption kinetics compared to magnesium hydride powder although the temperature of operation is still high.