Tang S.-L.,Central South University |
Li S.-L.,Central South University |
Fang Y.-H.,Central South University |
Fang Y.-H.,Haicang Branch Company |
And 3 more authors.
Fenmo Yejin Cailiao Kexue yu Gongcheng/Materials Science and Engineering of Powder Metallurgy | Year: 2010
Desorption properties are critical factor for Mg-based hydrogen storage materials applying. In the present paper, Mg2FeH6 composite and LaNi5 were synthesized by reactive mechanical alloying and melting, respectively. Then 70% (mass fraction) Mg2FeH6 composite was mixed with 30% LaNi5 to form a new composite by mechanical balling. Desorption measurements show that the new composite has good desorption kinetics. During desorption, the composite can desorb 1.46% (mass fraction) hydrogen at 553 K, while it only needs 120 s to releases 80% of total hydrogen desorption at 653 K, and the final hydrogen desorption is 3.6%. The addition of LaNi5 leads to the decrease of desorption temperature of Mg2FeH6 composite and the increase of desorption rate.
Zhou Z.,General Research Institute for Nonferrous Metals, China |
Zhou Z.,Haicang Branch Company |
Song Y.,General Research Institute for Nonferrous Metals, China |
Cui S.,General Research Institute for Nonferrous Metals, China |
And 5 more authors.
Journal of Alloys and Compounds | Year: 2010
MmNi4.2Co0.3Mn0.4Al0.3Mg 0.03 hydrogen storage alloy was prepared by single-roll rapid quenching followed by different annealing treatments for 8 h at 1133 K, 1173 K, 1213 K, and 1253 K, respectively. Alloy structure, phase composition, pressurecompositiontemperature (PCT) properties, and electrochemical performance of different annealed alloys have been investigated by X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), energy dispersion spectrometer (EDS), automatic Sieverts-type apparatus, and electrochemical experiments. Electrochemical experiments indicate that the annealing treatment at 1213K extends cycle life from 193 cycles to 358 cycles, increases the maximum discharge capacity, and slightly decreases the activation behavior. Alloy structure analyses show that the improvement in cycle life is attributed to the formation of a single CaCu5-type structure or the relief of an Mg-containing AlMnNi2-type second phase. Pressure composition isotherms results illustrate that both the hydrogen absorption capability and the dehydriding equilibrium pressure go up with increased annealing temperature. For its good performance/cost ratio, the Mg-added low-Co alloy annealed at 1213K would be a promising substitution for MmNi4.2Co0.3Mn 0.4Al0.3Mg0.03 alloy product. © 2010 Elsevier B.V. All rights reserved.