Introduction to Mg-based metal hydrides
This chapter gives an introduction to Mg-based metal hydrides for hydrogen storage applications.
Hydrogen absorption in magnesium is interesting for hydrogen storage applications due to its high weight capacity (7.6 wt%), its low cost, and abundance. However, MgH2 is very stable and should be desorbed at high temperature (573 K at 0.1 MPa). In addition, it is very sensitive to oxidation upon air exposure and has slow desorption kinetics. Therefore, many studies have been performed to improve the kinetics of H absorption and desorption in Mg by preparing nanometric powders and/or adding catalysts or additives to MgH2 [07S2, 09V1, 10A1, 10J1, 12C1]. The structural, thermodynamic, and kinetic properties of the Mg hydrides and the influence of nanostructuration and of various types of additives (metals, intermetallics, hydrides, oxide, carbon) will be presented.