Preparation and properties of porous metal hydride compacts

Analyses of hydrogen sorption kinetics and thermodynamics of magnesium–misch metal alloys

“…The recharging of an exhausted hydride pellet-tank is also expected to require less time than a powder-tank because, compared to the alloy powder, the alloy pellets have faster hydriding kinetics and lesser gas impedance. The Mg-x wt.% Mm alloy pellets also demonstrated a marked resistance to decrepitation similar to the pressed composites of high thermal conductors, which contain Al and Cu powder [12][13][14][15]. Although the heat of dehydrogenation of the Mg-x wt.% Mm hydrides in this study is relatively high, the dehydrogenation could be kept continuous if the waste heat produced by the energy converter (or exhaust system) could be directed to the system, as suggested in Fig.…”

A powder metallurgy approach for the production of a MgH2–Al composite material

“…Aluminum was chosen in view of several features interesting for this application, such as very good heat transfer capabilities, low density and relative low sintering pressure/temperature. The weight fraction of 20 wt.% has been chosen according to the investigation of Ron et al [10], who achieved promising results. Moreover, Al powder was cryomilled, as described in the following, so to keep the composite porosity as high as possible, not to hinder the inward and outward flux of gaseous hydrogen.…”

“…Different approaches to avoid the decrepitation during cycling have been suggested, all of them based on a similar principle. A second phase, such as ductile metals [10], expanded graphite [11], silica [7] or a polymer [9], is employed to reinforce the resulting composite and to prevent the hydride phase to decrepitate into smaller fragments. The matrix material should fulfill several requirements, including low density, high thermal conductivity and thermal stability.…”

Microencapsulation of Mg‐Ni hydrogen storage alloy

“…Compacting the storage materials into pellets is an effective method to avoid these problems. Ron et al (1980) proposed porous metallic matrix hydrides (PMHs) with which powdered hydrides and aluminum were thoroughly mixed, compacted and then sintered under high hydrogen pressure. They showed that PMHs have larger strength and higher thermal conductivity.…”