| Title |
Hydrogen Storage and Release Properties of Transition Metal-Added Magnesium Hydride Alloy Fabricated by Grinding in a Hydrogen Atmosphere |
| Authors |
(Sung Nam Kwon); (Hye Ryoung Park); (Myoung Youp Song) |
| DOI |
https://doi.org/10.3365/KJMM.2016.54.7.510 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
hydrogen absorbing materials; mechanical alloying/milling; microstructure; X-ray diffraction; addition of transition metals to magnesium hydride |
| Abstract |
90 wt% MgH2+5 wt% Ni+2.5 wt% Fe+2.5 wt% Ti (called MgH2+Ni+Fe+Ti), a hydrogen storage and release material, was fabricated by grinding in a hydrogen atmosphere, and then its quantities of stored and released hydrogen as a function of time were examined. A nanocrystalline MgH2+Ni+Fe+Ti specimen was made by grinding in a hydrogen atmosphere and subsequent hydrogen storage-release cycling. The crystallite size of Mg and the strain of the Mg crystallite after ten hydrogen storage-release cycles, which were obtained using the Williamson-Hall method, were 38.6 (±1.4) nm and 0.025 (±0.0081) %, respectively. The MgH2+Ni+Fe+Ti sample after the process of grinding in a hydrogen atmosphere was highly reactive with hydrogen. The sample exhibited an available storage capacity of hydrogen (the amount of hydrogen stored during 60 minutes) of about 5.7 wt%. At the first cycle, the MgH2+Ni+Fe+Ti sample stored hydrogen of 5.53 wt% in 5 minutes, 5.66 wt% in 10 minutes and 5.73 wt% in 60 minutes at 573 K and 12 bar of hydrogen. The MgH2+Ni+Fe+Ti after activation released hydrogen of 0.56 wt% in 5 minutes, 1.26 wt% in 10 minutes, 2.64 wt% in 20 minutes, 3.82 wt% in 30 minutes, and 5.03 wt% in 60 minutes. †(Received November 6, 2015; Accepted February 13, 2016) |