Study On Hydrogen Storage Properties Of Mg-Ti-Based Solid Solution

In the present work,(MgH2)50TiH2(40-x)Ni10Fex (x=0,3,6,9) and Mg(50-x)Ti40Ni10Alx(x=2,4,6,8) solid solution have been prepared by means of mechanical alloying (MA), besides, Mg(50-x)Ti40Ni10Alx(x=2,4,6,8) and Mg48Ti40Ni10Al2+5wt%M(M=V2O5, CeCl3) solid solution have been prepared by powder sintering and mechanical alloying. Various measurements have been carried out to determine the structure and hydrogen storage properties of these solid solution.For (MgH2)50TiH2(40-x)Ni10Fex(x=0,3,6,9), the study found that FCC appeared after50h ball-milling; BCC appeared after ball-milling for100h; with the increase of the ball-milling time, the peak of FCC weaken gradually, and the peak of BCC became sharp and wider progressively. The increase of Fe in samples was contributed to the appearance of BCC, but it reduced hydrogen storage properties. After ball-milling for100h, the hydrogen absorption of (MgH2)50TiH2(40) Niio (at300℃under30atm) amount to2.24wt%.As for Mg (5o-x) Ti40Ni10Alx(x=2,4,6,8) solid solution, prepared by mechanical alloying method under the condition of5atmH2, the results showed that the time and rules, appearance of FCC and BCC in the samples, were consistent with the former experiment, which demonstrated that the structure of the samples would not be influenced by using Mg to replace MgH2and Ti to replace TiH2. But the hydrogen absorption capacity of samples decreased obviously.The Mg(50-x)Ti40Ni10Alx(x=2,4,6,8) solid solution, prepared by powder sintering followed by mechanical alloying under the condition of5atm H2, the experiment exhibited that the time, FCC turning into BCC, shorten and simultaneously the hydrogen absorption capacity could improve after the sintering and ball-milling. Hydrogen absorption capacity of Mg50Ti40Ni10amount to5.25wt%through the sintering and then ball-milling for150h, while hydrogen absorption capacity is1.34%with ball-milling for150h directly without sintering. But after the sintering process and ball-milling, the content of hydrogen desorption reduced.The Mg48Ti40Ni10Al2+5wt%M (M=V2O5, CeCl3) solid solution, produced by powder sintering and then mechanical alloying under condition of60atmH2, the study showed that the rate of hydrogen absorption and the desorption capacity would be improved after ball-milling at60atmH2. The ability of absorption and desorption would reduce with the addition of5%wtCeCl3which also reduced the initial temperature of absorption of hydrogen and reaction enthalpy; with the addition of5wt%V2O5in sample, the ability of absorption and desorption reduced, at the same time, the initial temperature of hydrogen desorption rose and the reaction enthalpy decreased.