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Vol.52, No.12, 1031 ~ 1037, 2014
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| Title |
| Enhancement of Hydrogen-Storage Characteristics of Magnesium Hydride via Reaction-Involved Milling with Nickel and Lithium Borohydride |
| Myoung Youp Song , Young Jun Kwak , Seong Ho Lee , Hye Ryoung Park |
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| Abstract |
| Ni and LiBH4 with a high hydrogen-storage capacity of 18.4 wt% were added to MgH2. A sample with a composition of 86 wt% MgH2-10 wt% Ni-4 wt% LiBH4 (named MgH2-10Ni-4LiBH4) was prepared by milling under H2 (reaction-involved milling, RIM), and its hydriding and dehydriding properties were then examined. The activation of MgH2-10Ni-4LiBH4 for hydriding and dehydriding reactions was not required. The as-milled sample absorbed 2.54 wt% H for 5 min, 3.72 wt% H for 10 min, 4.90 wt% H for 20 min, and 4.90 wt% H for 60 min at 623 K under 12 bar H2, absorbing nearly 5 wt% H for 60 min. The as-milled sample desorbed 2.86 wt% H for 5 min, 4.78 wt% H for 15 min, and 4.94 wt% H for 60 min at 623 K under 1.0 bar H2. The inverse dependence of the hydriding rate on temperature is due to a decrease in the driving force for the hydriding reaction (the difference between applied hydrogen pressure and equilibrium plateau pressure) as the temperature increases. |
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| Key Words |
| hydrogen absorbing materials, mechanical alloying/milling, microstructure, X-ray diffraction, Mg-x wt% TaF5 |
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