Mg-3(BH4)(4)(NH2)(2) as Inorganic Solid Electrolyte with High Mg2+ Ionic Conductivity

Mg-3(BH4)(4)(NH2)(2) compound was synthesized through the investigation of the Mg(BH4)(2)-Mg(NH2)(2) phase diagram; its crystal structure was solved in a tetragonal unit cell with the space group I (4) over bar. Interestingly, Mg-3(BH4)(4)(NH2)(2) has a high thermal stability with a decomposition temperature above 190 degrees C and exhibits a high Mg2+ ionic conductivity of 4.1 x 10(-5) S.cm(-1) at 100 degrees C with a low activation energy (0.84 eV). The reversible Mg deposition/stripping was demonstrated at 100 degrees C when using Mg-3(BH4)(4)(NH2)(2) as solid electrolyte. Thus, Mg-3(BH4)(4)(NH2)(2) is a compound that could help to develop rechargeable Mg-ion solid-state batteries.