Structural insight into the magnesium borohydride - ethylenediamine solid-state Mg-ion electrolyte system.

A highly complex crystal structure of stoichiometric Mg 5 ( en ) 6 (BH 4 ) 10 was solved from single crystal synchrotron X-ray diffraction and confirmed by neutron powder diffraction (NPD) on isotopically substituted Mg( en ) 1.2 ( 11 BD 4 ) 2 . We highlight the role of the amorphous Mg(BH 4 ) 2 in the reactivity of the Mg(BH 4 ) 2 - en system and characterized a previously overlooked phase, Mg( en ) 2 (BH 4 ) 2 .