Keywords: hydrogen storage alloys, hydriding combustion synthesis, HCS, mechanical milling, magnesium, nickel, absorption capacity, vehicle applications, magnesium-based materials
Magnesium-nickel hydrogen storage alloys prepared by hydriding combustion synthesis followed by mechanical milling
Recent progress is reviewed in the preparation of highly active magnesium-based hydrogen storage alloys by the combined process of Hydriding Combustion Synthesis (HCS) and Mechanical Milling (MM). The structural transformation of the alloys during MM determined by means of X-ray Diffraction (XRD) and the hydrogen storage properties of the alloys measured by means of Pressure-Concentration-Temperature (PCT) are reported. The HCS alloy of Mg98Ni2 after MM showed the highest hydrogen capacity of 5.60 wt.% at 373 K within 100 s and the dehydriding onset decreased from about 640 K of the HCS product to 480 K of the HCS + MM product. Besides, the absorption capacity at 373 K in 30 s increased from 3.85 wt.% for the HCS + MM product of Mg95Ni5 without Nb2O5 to 5.09 wt.% for that with 1 at.% Nb2O5. The results demonstrated that the method of HCS + MM has potential in the preparation of magnesium-based materials for vehicular application.