TECHNOECONOMIC INSIGHTS INTO METAL HYDRIDES FOR

Metal hydride energy storage

Metal hydrides (MH x) are the most technologically relevant class of hydrogen storage materials because they can be used in a range of applications including neutron moderation, 1 electrochemical cycling, 2 thermal storage, 3 heat pumps, 4 and purification/separation. 5 While many alkali or sp metals also form saline or covalent hydrides, the recognition that transition metal hydrides, in particular, are in fact distinct compounds as distinguished from solid solutions of hydrogen is attributable to the band structure calculations of Switendick. 6 However, the attribute of relevance where application solutions are sought is the solid solution region of the phase diagram, between metal and hydride phases as shown in Figure 1.