Enhancement of Hydrogen Storage Characteristics of Mg by Addition of Nickel and Niobium (V) Fluoride via Mechanical Alloying

• Published in: Korean Journal of Metals and Materials Vol. 54; no. 3; pp. 210 - 216
• Main Authors: Song, Myoung Yeop, Kwak, Young Jun, Lee, Seong Ho, Park, Hye Pyoung
• Format: Journal Article
• Language: English
• Published: 대한금속·재료학회 01.03.2016
• Subjects: 재료공학
• ISSN: 1738-8228; 2288-8241
• DOI: 10.3365/KJMM.2016.54.3.210

A specimen with a composition of 80 wt% Mg+14 wt% Ni+6 wt% NbF5 (termed Mg-Ni-NbF5) was prepared by mechanical alloying. Its hydrogen absorption and release characteristics were then examined. Mg2NiH4 was formed by a reaction of Mg with nickel and hydrogen during mechanical alloying and hydrogen absorption-release cycling. The particles after hydrogen absorption-release cycling became smaller than those after mechanical alloying owing to the expansion and contraction of the particles upon cycling. The cycled Mg-Ni-NbF5 had a fairly high hydrogen absorption rate and a large hydrogen storage capacity, with an effective hydrogen storage capacity close to 5.6 wt% at 593 K. The cycled Mg-Ni-NbF5 absorbed 5.58 wt% H in 12 bar H2 and released 4.81 wt% H in 1.0 bar H2 at 573 K for 60 min. At 593 K, the cycled specimen absorbed 4.53 wt% H for 5 min, 5.27 wt% H for 10 min, 5.50 wt% H for 25 min, and 5.58 wt% H for 60 min in 12 bar H2, and released 1.28 wt% H for 5 min, 2.26 wt% H for 10 min, 4.13 wt% H for 30 min, and 4.81 wt% H for 60 min in 1.0 bar H2. KCI Citation Count: 20