Atom-efficient synthesis of a benchmark electrolyte for magnesium battery applications.

The benchmark magnesium electrolyte, [Mg 2 Cl 3 ] + [AlPh 4 ] - , can be prepared in a 100% atom-economic fashion by a ligand exchange reaction between AlCl 3 and two molar equivalents of MgPh 2 . NMR and vibrational spectroscopy indicate that the reported approach results in a simpler ionic composition than the more widely adopted synthesis route of combining PhMgCl with AlCl 3 . Electrochemical performance has been validated by polarisation tests and cyclic voltammetry, which demonstrate excellent stability of electrolytes produced via this atom-efficient approach.