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Home and abroad, in the system La-Mg-Ni Department of Non-AB above 5 alloy research focuses on the La-Mg-Ni based AB 2 -type alloy and AB 3 -type alloy characteristics of the crystal structure, hydrogen storage characteristics as well as two types of this alloy structure and hydrogen storage performance with distinction, and a preliminary analysis of the AB 3 type alloy hydride structure. Research for La 2-x of of MgNi , 9-5x (x = 0.0 to 1.0) alloy microstructure characterized by XRD and Rietveld method. The study showed that: La 2-x the of MgNi 9-5x (x = 0.0 to 1.0) alloy mainly by LaMgNi 4 and (La, Mg ) Ni 3 phase. In LaMgNi 4 phase, Mg occupies the the 4C position of La occupy 4a position. Mg easy access to La 1-x Mg x Ni 2 phase, with the increase in Mg / La ratio of until 1:1 alloy structure from a pseudobinary MgCu 2 -type disordered structure into three yuan MgCu 4 Sn-ordered super-structure, the structure remained stable form LaMgNi 4 phase. The remaining Mg element into the (La, Mg) Ni 3 phase of the Laves phase structure unit. Electrochemical and PCT test: LaMgNi 4 single-phase alloys at 50 ° C and 18atm hydrogen pressure maximum hydrogen absorption capacity 3.8H/fu LaMgNi 4 alloy absorption and desorption narrower than the poor and reversibility hydrogen PCT curve platform area resulting in lower electrochemical capacity for only 170mAh.g -1 . (La, Mg) Ni 3 phase, Mg occupy 6C position, its share is about 0.4, the PuNi 3 -La 2 MgNi 9 has the higher the electrochemical capacity La 2 the of MgNi 9 alloy electrochemical capacity reach 392mAh.g - 1 . By XRD and EPMA analysis of Al, Mn, Co, Sn, and Cu on the LaMgNi 4 alloy Alternate. LaMgNi 3.7 M 0.3 (M = Ni, Al, Mn, Co, Sn, Cu) alloy main phases are LaMgNi 4 phase, while contain a small amount of the impurity phase. Different alloying elements in LaMgNi 4 Sn, Al phase solid solubility of certain differences, in descending order of the solid solubility of Mn gt; of Cu gt; Co. gt; Al gt; Sn element added is not conducive to LaMgNi 4 phase formation. Maximum discharge capacity of the alloy electrode by 245.2mAh.g -1 (M = Sn) changes to 293.2mAh.g -1 (M = Co), and the cycle stability are poor. High rate discharge capacity of the alloy electrode HRD (I d = 900mA / g) order of Al gt; Sn gt; Cu gt; Mn gt; Ni gt; Co, hydrogen atoms in the alloy play a major role in the proliferation of high-rate discharge performance alloy MH electrode. Induction melting and casting La 0.67 Mg 0.33 Ni 3.0 alloys La elements burning control in 4% and Mg burning amount control in about 20% of the cases, the cast alloy after annealing at 850 ° C and 75h can guarantee that the relative abundance PuNi 3 -type phase at about 82wt%. Annealing time of growth can be the single phase better PuNi 3 -type alloy. The the XRD Rietveld method study La 1-x the Mg x Ni 3 (x = 0,0.33,0.67), alloy showed that: in PuNi 3 -type phase as the Mg content increases, the distance between the La, Mg, and Ni, and Ni and Ni atoms have a decreasing trend. And La LaNi 3 0.67 Mg 0.33 Ni 3 alloy between AB 2 0.67 Mg 0.33 Ni 3 to La 0.33 Mg 0.67 Ni 3 alloy between the amount of change. This may be the increase of the Mg content, the storage of the number of hydrogen atoms in the unit Aeromonas reduced and the amount of change of the hydrogen storage capacity of the Laves unit has accelerated the trend of one of the main. La 0.67 Mg 0.33 Ni 2.5 Co 0.5 by XRD and NRD (neutron diffraction) and La 0.75 Mg 0.25 Ni 3.0 Co 0.5 alloy microstructure analysis showed that: in PuNi 3 -type structure, Mg elements occupy Laves unit 6c position, Co elements occupy in 18h and 6C position, and Co elements are mainly distributed in the PuNi 3 -type structure AB 5 unit , and AB of 5 unit AB 2 unit coherent surface in the AB 2 the 3b position within the unit does not seem to exist. CE 2 Ni 7 -type structure, Mg elements occupy the position of the Laves unit 4f, Co elements occupy 4e, 4f, 6h, and 121, while in the interior of the Laves unit the 2b position missing found no Co atom, Co atoms mainly distributed in the Ce 2 Ni 7 -type structure the AB 5 unit and AB 5 unit AB 2 coherent surface of the unit. Analysis by Rietveld method
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