(42b) LiMn(BH4)3 for On-Board Hydrogen Storage

In
this study, a promising complex borohydride LiMn(BH₄)₃
was evaluated for on-board hydrogen storage.  This new complex hydride was
prepared from the precursor materials LiBH₄ and MnCl₂via
the solid state mechano-chemical process.  The B-H stretch occurrence at 2374
cm^-1in addition to two other B-H bonding bands of LiBH₄
(2228 and 2297 cm^-1) from the FTIR investigation confirm the
formation of LiMn(BH₄)₃ at room temperature.  Gas
chromatography studies of both undoped and doped LiMn(BH₄)₃
demonstrate that the evolved gas is mainly hydrogen and does not contain
members of the borane family.  Though this complex LiMn(BH₄)₃
exhibits high theoretical hydrogen storage capacity (~8 wt.%) at lower
temperature (<150 ^oC), the reversible hydrogenation and
dehydrogenation cycling is not promising.  A strategy has been adopted to convert
this new material to become reversible, and these results will also be presented.