Hydrogen-Storage Property Enhancement of Magnesium Hydride by Nickel Addition via Reactive Mechanical Grinding

作者：Kwak Young Jun; Lee Seong Ho; Park Hye Ryoung; Song Myoung Youp^*

来源：Journal of the Korean Institute of Metals and Materials, 2013, 51(8): 607-613.

DOI：10.3365/KJMM.2013.51.8.607

• hydrogen absorbing materials
• mechanical alloying/milling
• microstructure
• X-ray diffraction
• starting materials MgH2 and Ni

In this work, MgH2 was employed as a starting material rather than Mg. Samples with compositions of 94 wt% MgH2-6 wt% Ni and 85 wt% MgH2-15 wt% Ni were prepared by reactive mechanical grinding. They were named MgH2-6Ni and MgH2-15Ni, respectively. Their hydriding and dehydriding properties were then examined and compared. The activation of MgH2-6Ni and MgH2-15Ni was completed after just the first hydriding (under 12 bar H-2)-dehydriding (in vacuum) cycle at 573 K. MgH2-6Ni after reactive mechanical grinding has a larger specific area and a slightly smaller mean particle size (37 m(2)/g, 1.22 mu m) than MgH2-15Ni after reactive mechanical grinding (30 m(2)/g, 1.24 mu m). The activated MgH2-15Ni has slightly lower hydriding rates and a smaller quantity of hydrogen absorbed for 60 min at 573 K under 12 bar H-2 than MgH2-6Ni. At 573 K under 1.0 bar H-2, the activated MgH2-6Ni at first had a higher dehydriding rate than the activated MgH2-15Ni; however, the activated MgH2-15Ni had higher dehydriding rates after approximately 10 min and a larger quantity of hydrogen desorbed for 60 min than the activated MgH2-6Ni. The decrease in particle size and creation of defects due to Ni addition via reactive mechanical grinding are considered to increase the hydriding and dehydriding rates of MgH2.

• 出版日期2013-8