Physicochemical, spectroscopic and electrochemical characterization of magnesium ion-conducting, room temperature, ternary molten electrolytes

• Published in: Journal of power sources Vol. 195; no. 13; pp. 4356 - 4364
• Main Authors: Narayanan, N.S. Venkata, Ashok Raj, B.V., Sampath, S.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2010; Elsevier
• Subjects: Acetamide-based eutectics; Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; Magnesium ion-conductivity; Magnesium rechargeable battery; Room temperature molten electrolyte; Magnesium ion-conductivity; Room temperature molten electrolyte; Acetamide-based eutectics; Magnesium rechargeable battery; Ionic conductivity; Molten electrolyte; Secondary cell; Magnesium; Physicochemical properties; Room temperature; Electrochemical characteristic
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/j.jpowsour.2010.01.070

Room temperature, magnesium ion-conducting molten electrolytes are prepared using a combination of acetamide, urea and magnesium triflate or magnesium perchlorate. The molten liquids show high ionic conductivity, of the order of mS cm −1 at 298 K. Vibrational spectroscopic studies based on triflate/perchlorate bands reveal that the free ion concentration is higher than that of ion-pairs and aggregates in the melt. Electrochemical reversibility of magnesium deposition and dissolution is demonstrated using cyclic voltammetry and impedance studies. The transport number of Mg 2+ ion determined by means of a combination of d.c. and a.c. techniques is ∼0.40. Preliminary studies on the battery characteristics reveal good capacity for the magnesium rechargeable cell and open up the possibility of using this unique class of acetamide-based room temperature molten electrolytes in secondary magnesium batteries.