A Comparison Study of Hydrogen Storage Thermodynamics and Kinetics of YMg11Ni Alloy Prepared by Melt Spinning and Ball Milling

Abstract

Melt spinning (MS) and ball milling (BM) were employed to fabricate YMg 11 Ni alloy, and their structures and hydrogen storage performances were examined. The results reveal that the as-spun and as-milled alloys both exhibit the nanocrystalline and amorphous structure. The as-milled alloy shows a larger hydrogen absorption capacity as compared with the as-spun alloy. More than that, the as-milled alloy exhibits lower onset hydrogen desorption temperature than the as-spun one, which are 549.8 and 560.9 K, respectively. Additionally, the as-milled alloy shows a superior hydrogen desorption property to the as-spun one. On the basis of the time needed by desorbing hydrogen of 3 wt% H 2 , for the asmilled alloy, it needs 1106, 456, 343, and 180 s corresponding to hydrogen desorption temperatures of 593, 613, 633, and 653 K. However, for the as-spun alloy, the time needed is greater than 2928, 842, 356, and 197 s corresponding to the same temperatures. Hydrogen desorption activation energies of as-milled and as-spun alloys are 98.01 and 105.49 kJ/mol, respectively, which is responsible for that the as-milled alloy possesses a much faster dehydriding rate. By means of the measurement of pressure-composition-temperature (P-C-T) curves, the dehydrogenation enthalpy change of the alloys prepared by MS (DH de (MS)) and BM (DH de (BM)) is 81.84 and 79.46 kJ/mol, respectively, viz. DH de (MS) [ DH de (BM).

Temperature-Dependent SRS Behavior of 316L and Its Constitutive Model

“…Each model has its specialty and applicable scope. For example, Arrhenius model is based on the thermally activated theory and has significant physical meaning [28,29], but SRS, TS and SH behaviors are not clearly presented in this model. Moreover, the artificial neural network method is based on artificial intelligence technology as a black box, which cannot visually represent SRS and TS behaviors.…”

A Comprehensive Review on Hydrogen Absorption Behaviour of Metal Alloys Prepared through Mechanical Alloying

“…Furthermore, the hydriding kinetics of MgH2 hydride is relatively slow because the dissociation of molecular hydrogen into hydrogen atoms is difficult on the surface of Mg metal [43]. Several reports are found in the literature concerning synthesis and hydrogen properties of Mg-based alloys synthesized by mechanical alloying [3,[44][45][46]. Another interesting study is (a-c) were reprinted with permission from [36], with permission from Elsevier, 2016 (d) reproduced from [37], with permission from Elsevier, 2015; (e) reproduced from [38], with permission from Elsevier, 2000 and (f) reproduced from [39], with permission from Elsevier, 1999.…”

“…Furthermore, the hydriding kinetics of MgH 2 hydride is relatively slow because the dissociation of molecular hydrogen into hydrogen atoms is difficult on the surface of Mg metal [43]. Several reports are found in the literature concerning synthesis and hydrogen properties of Mg-based alloys synthesized by mechanical alloying [3,[44][45][46]. Another interesting study is Andreasen [31].…”

“…Melt-spinning technique is a useful method that is used to change structures of as-cast alloys to amorphous structure. This method improves the amorphous nature of materials by reducing their grain size [44]. The only problem related to this method is the poor cycle stability of the melt-spun alloys, due to the disappearing of the metastable structures generated by melt-spinning [78].…”

Hydrogen Storage Performances of Nanocrystalline and Amorphous NdMg11Ni + x wt% Ni (x = 100, 200) Alloys Synthesized by Mechanical Milling

“…Mg-based alloys are highly anticipated by researchers in the field of hydrogen vehicles due to their good capacity. The excellent gaseous hydrogen storage capacity of 3.7-6.0 wt% [4] and the theoretical electrochemical capacity (over 1000 mAh/g) [5] make researches play more and more attention to the REMg 12 -type (RE = Nd, Sm and La) Mg-based metallic hydrides. However, there are still unresolved questions such as sluggish dehydriding/hydriding kinetics, comparatively high temperature of dehydrogenation, bad cycle stability and dramatically low electrochemical discharging capacity, which are the main technical obstacles restricting the widespread use of Mg-based alloys in on-board hydrogen storage system and Ni-MH cell system.…”