An overview of the different types of metal hydrides and complex hydrides being investigated for on-board (reversible) and off-board (non-reversible) hydrogen storage will be presented along with a few new approaches to improving the hydrogenation- dehydrogenation properties. In the interest of high gravimetric capacities, much of the current metal hydride reasearch is focused on hydrides composed primarily of light elements (Z ≤ 13). For reversible hydrides, much attention has recently been devoted to the complex hydrides, where the hydrogen atoms are covalently bonded to a central atom in an anion complex (e.g. [AlH6]3-, [AlH4]-, [BH4]-, [NH2]-) and stabilized by a cation, typically an alkali (e.g. Li) or alkaline earth metal (e.g. Mg). These compounds have appreciable gravimetric hydrogen storage capacities, but are plaqued by slow kinetics and high decomposition temperatures. 
 
The development of an off-board ... More