Structural and hydrogen storage capacity evolution of
Mg2FeH6hydride synthesized by reactive mechanical alloying①
Mg2FeH6hydride synthesized by reactive mechanical alloying①
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;2. Department of Mechanical Engineering, University of Waterloo,
Waterloo, Ontario, Canada N2L 3G1)
Waterloo, Ontario, Canada N2L 3G1)
Abstract: Mg-based metal hydrides are promising as hydrogen storage materials for fuel cell application. In this work,Mg2FeH6 complex hydride phase was synthesized by controlled reactive ball milling of 2Mg-Fe (atomic ratio) powder mixture in H2. Mg2FeH6is confirmed to be formed via the following three stages: formation of MgH2via the reaction of Mg with H2, incubation stage and formation of Mg2FeH6by reaction of fully refined MgH2 and Fe. The incubation stage is characterized by no traces of Mg or hydride crystalline phase by XRD. On the other hand, Mg is observed uniformly distributed in the milled powder by SEM-EDS. Also, almost the same amount of H2 as the first stage is detected stored in the powders of the second stage by DSC and TGA.
Key words: hydrogen storage materials; hydride; fuel cell; mechanical alloying; solid state synthesis