The effects of Co and Ni addition on the hydrogen storage properties of Mg_3Mm

摘要

The effects of Ni and Co addition on the hydrogen storage properties of Mg_3Mm alloy was studied by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and pressure-composition isotherm (PCI) measurement. The hydrogen absorption kinetics and the thermodynamic parameters (apparent AH, AS) for Mg_3Mm dehydrogenation reactions in Mg_3Mm, Mg_3MmNi_(0.1) and Mg_3MmNi_(0.1)Co_(0.1) alloys have been also investigated. The maximum hydrogen storage content of Mg_3Mm, Mg_3MmNi_(0.1) and Mg_3MmNi_(0.1)Co_(0.1) alloys was improved due to that the addition of Ni and/or Co further spurred the MmH_3 phase transforming to MmH_2 phase. On the other side, the kinetics curves show the addition of Co could enhance hydrogen absorption rate while the addition of Ni change the hydrogenation reaction mechanism.