Abstract:The hydrogen storage properties of the nanocomposite Mg₉₅Ni₃(MnO₂)₂ (mass fraction, %) were studied. The temperature changes in hydriding/dehydriding process were investigated. The nanocomposite was fabricated by ball milling process of mixed elemental Mg, Ni and oxide maganese MnO₂ under hydrogen pressure (approximately 0.6MPa). The hydrogen absorption and desorption properties of the samples milled for various times were investigated. A remarkable enhancement of hydrogen absorption kinetics and low operational desorption temperature have been found after the sample milled for over 57h. For example, this nanocomposite can absorb hydrogen more than 6.0% (mass fraction) in 60s at 200℃ under 2.0MPa, and desorption capacity also exceeds 6.0%  (mass fraction) in 400s at 310℃ under 0.1MPa. The storage properties of samples milled for various times were studied and the kinetics of the samples were analyzed.

Key words: mechanical milling; nanocomposite Mg-Ni-MnO₂; hydrogen storage materials