Ni-induced destabilization dynamics of crystalline zinc borohydride

Fundamental understanding of the role of Ni additives in promoting the dehydrogenation mechanism of hydrogen desorption in zinc borohydride [Zn(BH4)(2)] is a key factor for using this material in hydrogen storage. A systematic theoretical study of the energetics and hydrogen dynamics was carried out to understand this dehydrogenation mechanism. The energetic calculations reveal that Ni substitutes Zn in preference to B. H atoms are pulled toward these doped Ni atoms, which introduce instability via the breaking of multiple B-H bonds in the complex borohydride. The mechanistic understanding gained from this study can be applied to the design of better hydrogen storage materials. (C) 2008 American Institute of Physics.