(LiNH2-MgH2):: a viable hydrogen storage system

One of the problems related to the employment of hydrogen-based fuel cells for vehicular transportation is "on board" storage. Hydrogen storage in solids has long been recognized as one of the most practical approaches for this purpose. The capacity of existing storage materials is markedly below that needed for vehicular use. Recently Chen et al. [Nature 420 (21) (2002) 302; J. Phys. Chem. B 107 (2003) 10967] reported a lithium nitride/imide system, with a high capacity, 11.5 wt.%, however, its operating temperature and pressure are not satisfactory for vehicular application. In this research a new storage material has been developed, which is from the partial substitution of lithium by magnesium in the nitride/imide system. The plateau pressure of this new Mg-substituted system is about 30 bar and 200degreesC with a H capacity of 4.5 wt.% and possibly higher. This is a very promising H-storage material for "on board" storage for vehicular applications. (C) 2004 Elsevier B.V. All rights reserved.