Hydrogen storage properties of the mechanically milled MgH2–V nanocomposite

Effect of reactive mechanical grinding on chemical and hydrogen sorption properties of the Mg+10 wt.% Co mixture

“…It also allows the activation procedure (which is generally required prior to the first absorption reaction) to be suppressed. However, results published elsewhere [17], [19] and [20] using MgH 2 as a starting material are always slightly better than our results. Some experiments are underway on the MgH 2 -Co mixture submitted to RMG.…”

“…and C=kD H (P 0 1/2 −P eq 1/2 ) where r is the crystallite radius, k the rate constant which depends on temperature and pressure, P o the applied pressure and P eq the equilibrium pressure (calculated according to the thermodynamic properties published by Liang et al [17] i.e. ln P eq =−74 400/RT+133.5/R).…”

New FCC Mg–Zr and Mg–Zr–ti deuterides obtained by reactive milling

“…However, the high thermal stability and slow kinetics of its rutile-type structure significantly hinder its widespread use in commercial energy storage systems. Many factors such as a chemical composition [2][3][4] , addition of catalytic species [5][6][7][8][9][10] , processing technologies 5,[11][12][13][14] and microstructural parameters, particularly grain size 6,[15][16][17] , have an effect on the hydrogen storage capacity, kinetics and/or thermodynamics of Mg-based intermetallic compounds. Conventional crystalline alloys often suffer from relatively slow hydrogen sorption kinetics even at high temperatures, while nanocrystalline and amorphous materials exhibit much faster kinetics at lower temperatures, as their large number of interfaces, defects and grain boundaries, provide easy pathways for hydrogen diffusion [18][19][20][21] .…”

Magnesium Hydride: From the Laboratory to the Tank

“…In order to increase the milling efficiency, we changed both the rotation speed and the number of balls in the vials. Then, for the same mixtures (i. e. Mg + 10 % Cr 2 O 3 ) it was possible to reach a full conversion of Mg into MgH 2 in 5 h with a rotation speed of 300 rpm and with 34 balls, whereas at 200 rpm and with 17 balls, the fraction of MgH 2 was only about 80 % after 10 h. Liang et al [12] have even reached a full conversion in less than an hour by heating the vials to 200 • C during milling. In this last case the milling energy is added to the thermal energy and thus the hydrogenation of magnesium becomes very fast.…”