Superhalogens are species whose electron affinity (EA) or vertical detachmentenergy (VDE) exceed to those of halogen. These species typically consist of acentral electropositive atom with electronegative ligands. The EA or VDE ofspecies can be further increased by using superhalogen as ligands, which aretermed as hyperhalogen. Having established BH4- as a superhalogen, we havestudied BH4-x(BH4)x- (x = 1 to 4) hyperhalogen anions and their Li-complexes,LiBH4-x(BH4)x using density functional theory. The VDE of these anions islarger than that of BH4-, which increases with the increase in the number ofperipheral BH4 moieties (x). The hydrogen storage capacity of LiBH4-x(BH4)xcomplexes is higher but binding energy is smaller than that of LiBH4, a typicalcomplex hydride. The linear correlation between dehydrogenation energy ofLiBH4-x(BH4)x complexes and VDE of BH4-x(BH4)x- anions is established. Thesecomplexes are found to be thermodynamically stable against dissociation intoLiBH4 and borane. This study not only demonstrates the role of superhalogen indesigning new materials for hydrogen storage, but also motivatesexperimentalists to synthesize LiBH4-x(BH4)x (x = 1 to 4) complexes.
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