Influence of Complexing Additives on the Reversible Deposition/Dissolution of Magnesium in an Ionic Liquid

Aiming at a fundamental understanding of the synergistic effects different additives on electrochemical Mg deposition/dissolution in an ionic liquid, we have systematically investigated these processes combined and theoretical study, using 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl) imide (BMP-TFSI) as solvent cyclic ether (18-crown-6) magnesium borohydride additives. Both crown BH4− improve deposition, its reversibility, cycling stability. The presence both their concentration relative to that Mg2+ are decisive for more facile reversible deposition/dissolution. These results those quantum chemical calculations indicate 18-crown-6 can partly displace TFSI− from direct coordination Mg2+. Furthermore, interaction between directly coordinated is weakened by with 18-crown-6, preventing Mg+-induced decomposition. Finally, deposition improved weaker overall upon reduction Mg+.