Study On The Preparation Technology And Hydrogen Storage Property Of AB₃-type La_xMg_1-XNi_Y Alloys

Hydrogen energy is considered as the edeal energy in21th century for it has a series ofadvantage, such as widely source、easy recycling、cleaning、efficient and good combustionperformance. While hydrogen storage technology is the key factor which restrict theapplication of hyrdrogen energy. Hydrogen storage alloy has a series of advantages, such ashigher hydrogen storage density、high security、low cost and relatively mature technology,which leads to be considered as the ideal and meaningful hydrogen storage technology.La-Mg-Ni series AB₃type hydrogen storage alloys are considered as the alloys which mostpossibly replace AB5type hydrogen storage alloys to be the new generation of hydrogenstorage alloy for practical application. Focus on the present industrialized productionproblems of La-Mg-Ni series AB₃type hydrogen storage alloys, according to the actualconditions, the hydrogen storage properties and microstructure for the La-Mg-Ni series AB₃type hydrogen storage alloys were investigated using XRD、SEM and PCT.In this paper the effect of the preparation technology on the structure and properties ofthe hydrogen storage alloys have been studied. The results show that adding cover-agent caneffectively reduce volatilization of Mg during the melting process. Different teemingtechnologys have great influence on the structure and character of hydrogen storage alloys.With the fixed compostion for melting, the alloys prepared by Copper water-cooled castingtechnology have higher hydrogen storage capacity than that prepared by fast melting spinningtechnology, which is due to that water-cooled casting technology can limit the amount of Mgvolatilization in the alloys, the amount of Mg volatilization of the alloys is only10-15%andrelatively lower than that of prepared by melting spinning of higher than15%.The temperature of heat treatment and times for annealing process were also applied tostudy the relationship between the properties with the microstructure of La_0.7Mg_0.3Ni_3.25alloy.The result shows that La_0.7Mg_0.3Ni_3.25alloy annealed at1173K for4h has the highesthydrogen storage capacity and content of （LaMg）₂Ni₇phase.