Investigation On The Electronic Structures And Hydrogen Storage Properties Of Mg-based Hydrogen Storage Alloys

In this dissertation, the electronic structures and hydrogen storage properties of Mg-based hydrogen storage alloys have been investigated. For one thing, the electronic structures of Mg₂Ni alloys and its hydride were calculated by first-principle plane-wave pseudopotential method, and the bonding characteristics were analyzed. The difference in electronic structures between LT(low temperature phase)-Mg₂NiH₄ and HT(high temperature phase)-Mg₂NiH₄ were discussed. The electronic structures of La₂MgNi₉ and LaMg₂Ni₉ were studied by the same method. The difference in hydrogen storage properties between La₂MgNi₉ and LaMg₂Ni₉ were explained by the electronic structure analysis. For another, La_1+xMg_2-xNi₉ (x=0, 0.5, 1.0, 1.5) alloys were prepared in high frequency induction furnace under Ar atmosphere, the characteristics of alloy phases and the properties of hydrogen storage and electrochemistry at different contents of La and Mg were studied. In Mg₂NiH₄ compounds, there is strong s-p-d hybridization between Ni and H in Ni-H bonding areas, which is a reason why Mg₂NiH₄ compounds have poor dynamic property. After the LT→HT phase transformation, the...