Evolution of the phase structure and hydrogen storage thermodynamics and kinetics of Mg 88 Y 12 binary alloy

An investigation on hydrogen storage thermodynamics and kinetics of Nd–Mg–Ni-based alloys synthesized by mechanical milling

“…The experimental alloy with a chemical composition of NdMg 11 Ni was prepared using a vacuum induction furnace in a helium atmosphere at a pressure of 0.04 MPa to prevent Mg from volatilizing. The molten alloy was poured into a copper cooled mould and then a cast ingot was obtained.…”

“…Milling speed was 135 rpm and duration time was 5, 10, 20, 40 and 60 h, respectively. For simplicity, the chemical composition of ball-milled alloys were defined as NdMg 11 Ni þ x wt.% Ni (x ¼ 100, 200), and the hydrogen storage capacity of the samples were calculate based on NdMg 11 Ni (excluding the mass of carbonyl nickel powder during ball milling).…”

“…Most of the papers published by International Symposium on Metal Hydrogen System Fundamental and Applications, Manchester, UK, July 2014 (MH2014) still concentrate on the investigation of Mg-based hydrogen storage alloy. Especially, the Mg-rich rare eartheMg-based alloy has attracted increasing interest due to its gaseous hydrogen storage capacity of 3.7e6.0 wt.% [10,11] and theoretical electrochemical capacity of over 1000 mAh/g [12], much higher than that of MgeNi alloy. However, some inherent issues of Mg-based alloys, such as relatively high hydrogen desorption temperature, sluggish hydriding/dehydriding kinetics and extremely low electrochemical discharge capacity at room temperature, severely hinder their practical application.…”

“…Zhang et al [23] reported that the as-spun Mg 10 NiR (R ¼ La, Nd and Sm) alloys displayed superior hydriding and dehydriding kinetics as a result of adding different rare earth elements. Yartys et al [24] reported that the LaMg 11 Ni alloy solidified at the highest cooling rate exhibited the fastest hydrogenation kinetics, reaching maximum hydrogenation capacity of 5.02 wt.% H.…”

“…Hence, Mg in the NdMg 12 -type alloy was partially substituted by Ni in the present work. The nanocrystalline and amorphous NdMg 11 Ni þ x wt.% Ni (x ¼ 100, 200) alloys were prepared by mechanical milling, and the effects of Ni content and milling time on the hydrogen storage kinetics performance of alloys have been investigated in detail.…”