A novel magnesium electrolyte containing a magnesium bis(diisopropyl)amide-magnesium chloride complex for rechargeable magnesium batteries

摘要

We developed a unique class of non-Grignard, weakly nucleophilic magnesium electrolytes based on a simple mixture of magnesium compounds: magnesium bis(diisopropyl)amide (MBA) and magnesium chloride (MgCl2). A new active species [(C3H7)(2)N]MgCl2-MgCl confirmed by NMR spectroscopy and DFT theoretical calculations affords low over-potentials for overall Mg deposition-dissolution without extra conditioning or activation and high and stable cycling coulombic efficiencies. The reduced corrosive nature toward non-noble metals (up to 2.10 V on stainless steel and copper) can be achieved after the addition of AlCl3. The MBA-2MgCl(2)/THF electrolyte exhibits good compatibility with the Mo6S8 cathode and the MBA-2MgCl(2) + AlCl3/THF electrolyte is more applicable for high energy density Mg-S batteries. Overall, this study demonstrates a novel strategic approach to develop highly efficient new electrolyte systems for rechargeable magnesium batteries.