Phase structure and electrochemical properties of laser sintered La2MgNi9 alloys were studied. The sintered alloys contained a main phase, LaNi5, and a ternary La-Mg-Ni phase, with a PuNi3 structure and a small amount...Phase structure and electrochemical properties of laser sintered La2MgNi9 alloys were studied. The sintered alloys contained a main phase, LaNi5, and a ternary La-Mg-Ni phase, with a PuNi3 structure and a small amount of LaMgNi4. The ternary La-Mg-Ni phase with a PuNi3 structure had the composition of La1.8Mg1.2Ni9 and La2MgNi9, for alloys laser sintered at 1000 and 1400 W, respectively. Owing to further reactions between LaNi5 and LaMgNi4, the amount of the PuNi3 phase increased for alloys sintered at 1400 W. Both alloys had good activation property （three charge/discharge cycles）. The discharge capacities of the sintered alloys were 321.8 and 344.8 mAh/g, respectively. Compared with the alloy laser sintered at 1000 W, the poor cyclic stability of the alloy sintered at 1400 W was mainly attributed to the lower corrosion resistance of the La2MgNi9 phase.展开更多
The hydrogen absorption amount and kinetics of the slurry formed by suspending the MgNi alloy powder in liquid benzene were studied. It is discovered that hydrogen is absorbed by both the solid phase(alloy) and liquid...The hydrogen absorption amount and kinetics of the slurry formed by suspending the MgNi alloy powder in liquid benzene were studied. It is discovered that hydrogen is absorbed by both the solid phase(alloy) and liquid phase(C 6H 6) and the hydrogen absorption rate varies with the temperature and the content of the Mg-Ni in the slurry. Most hydrogen absorption curves of the slurry fall into two regions, in which the mechanism of hydriding reaction in the slurry system is different. In the former region, the hydriding of the alloy proceeds with hydrogen diffusing through C 6H 6. The part in the second region is the outcome of the hydrogenation of C 6H 6. At 548 K and under the hydrogen pressure of 4.5 MPa the saturation capacity for the slurry of 80% C 6H 6(mass fraction)+20% MgNi(mass fraction) is 5.9% (mass fraction) hydrogen, which is 97% of the theoretic capacity of the slurry system. The hydride of the alloy MgNi, which is only the hydride of Mg 2Ni phase, Mg 2NiH 4, is an efficient catalyst for the hydrogenation of C 6H 6 into C 6H 12(C 6H 6+3H 2→C 6H 12) in the slurry system.展开更多
基金the Natural Science Foundation of Anhui Province (070414159)the Science Research Foundation for the Candidates of Academic Leaders of Anhui Proince
文摘Phase structure and electrochemical properties of laser sintered La2MgNi9 alloys were studied. The sintered alloys contained a main phase, LaNi5, and a ternary La-Mg-Ni phase, with a PuNi3 structure and a small amount of LaMgNi4. The ternary La-Mg-Ni phase with a PuNi3 structure had the composition of La1.8Mg1.2Ni9 and La2MgNi9, for alloys laser sintered at 1000 and 1400 W, respectively. Owing to further reactions between LaNi5 and LaMgNi4, the amount of the PuNi3 phase increased for alloys sintered at 1400 W. Both alloys had good activation property （three charge/discharge cycles）. The discharge capacities of the sintered alloys were 321.8 and 344.8 mAh/g, respectively. Compared with the alloy laser sintered at 1000 W, the poor cyclic stability of the alloy sintered at 1400 W was mainly attributed to the lower corrosion resistance of the La2MgNi9 phase.
文摘The hydrogen absorption amount and kinetics of the slurry formed by suspending the MgNi alloy powder in liquid benzene were studied. It is discovered that hydrogen is absorbed by both the solid phase(alloy) and liquid phase(C 6H 6) and the hydrogen absorption rate varies with the temperature and the content of the Mg-Ni in the slurry. Most hydrogen absorption curves of the slurry fall into two regions, in which the mechanism of hydriding reaction in the slurry system is different. In the former region, the hydriding of the alloy proceeds with hydrogen diffusing through C 6H 6. The part in the second region is the outcome of the hydrogenation of C 6H 6. At 548 K and under the hydrogen pressure of 4.5 MPa the saturation capacity for the slurry of 80% C 6H 6(mass fraction)+20% MgNi(mass fraction) is 5.9% (mass fraction) hydrogen, which is 97% of the theoretic capacity of the slurry system. The hydride of the alloy MgNi, which is only the hydride of Mg 2Ni phase, Mg 2NiH 4, is an efficient catalyst for the hydrogenation of C 6H 6 into C 6H 12(C 6H 6+3H 2→C 6H 12) in the slurry system.
