Mixed ionic liquids as electrolyte for reversible deposition and dissolution of magnesium

In this paper we reported for the first time mixing two ionic liquids of 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF4) and N-methyl-N-propylpiperidinium bis(ttifluoromethanesulfonyl)imide (PP13-TFSI) in the presence of 0.3 M Mg(CF3SO3)(2) for use as electrolyte of reversible magnesium deposition and dissolution. Three kinds of mixture with volume ratios of 2:1, 3:1 and 4:1 for BMIMBF4 and PP13-TFSI were chosen and the magnesium deposition-dissolution process was investigated via coin cells. The mixed solution provided lower initial deposition-dissolution overpotential than every single ionic liquid system and the overpotential decreased with increasing the content of BMIMBF4. The mixture with 4:1 exhibited extreme low initial overpotential and the reversible process can be maintained over 200 cycles. (c) 2006 Elsevier B.V. All rights reserved.