Hydrogen storage measurements in novel Mg-based nanostructures produced via rapid solidification and devitrification
Nanostructured materials for hydrogen storage with a composition of Mg85Ni15-xMx (M=Y or La, x=0 or 5) are formed by devitrification of amorphous and amorphous-nanocrystalline precursors produced by melt-spinning. All three compositions exhibit a maximum storage capacity of about 5 mass % H at 573 K. When ball-milled for 30 min in hexanes, the binary alloy can be activated (first-cycle hydrogen absorption) at 473 K. Desorption in this sample begins at 525 K, compared to 560 K when the material is activated at 573 K. The decrease in desorption temperature is attributed to a decrease in hydride crystallite size, and is consistent with thermodynamic calculations. Additions of Y and La improve the degradation in storage capacity observed during cycling of the binary alloy by slowing microstructural coarsening. Alloying with La also shows a slight improvement in the thermodynamics of hydride formation and decomposition. The improved thermodynamics are discussed in terms of destabilization of the hydrides relative to new equilibrium phases introduced by alloying additions.
Hydrogen storage measurements in novel Mg-based nanostructures produced via rapid solidification and devitrification, International Journal of Hydrogen Energy, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=908160
(Accessed May 31, 2023)