MgTFSI 2 /MgCl 2  /DME Solution Structure Analysis

  • Salama M
  • Shterenberg I
  • Gofer Y
  • et al.
Citations of this article
Mendeley users who have this article in their library.
Get full text


Recently, MgTFSI 2 /MgCl 2 electrolyte solutions in dimethoxyethane (DME) have been shown to function as viable electrolyte solutions for secondary Mg batteries that can facilitate reversible magnesium deposition/dissolution 1 . MgCl 2 is a crucial component in these solutions. On its own, however, it is practically insoluble in DME. Therefore, the fact that it is readily dissolved in MgTFSI 2 /DME solution is remarkable. Addition of MgCl 2 greatly improves the electrochemical performance of MgTFSI 2 /DME electrolyte solutions. MgTFSI 2 /DME electrolyte show large overpotential for deposition (-0.6 V vs Mg) and dissolution (1.5V vs Mg). Furthermore this electrolyte exhibit poor magnesium deposition reversibility. Adding MgCl 2 to this electrolyte reduces the overpotentials for both deposition and dissolution and showed 98% columbic efficiency. Thus, identifying the species formed in MgTFSI 2 /MgCl 2 solutions are very intriguing. In this study, we identified numerus solution species that some of them were not previously identified. We believe that the newly discovered Mg x Cl y complexes play a crucial rule in the improved electrochemical performance of the MgTFSI 2 /DME electrolyte solutions. The complexes that were identified were Mg 3 Cl 4 2+ (figure 1) 2 , Mg 2 Cl 2 2+ .Furthermore we showed that the hexacoordinated nature of magnesium effectively dictate the solution structure. We showed that in THF based electrolyte Mg 2 Cl 3 + is the dominant solution specie and we didn’t see any evidence for its existence in DME based electrolytes(. We implemented a wide variety of analytical tools, including single crystal X-ray diffraction, multinuclear NMR, and Raman spectroscopy, to elucidate the structure of these solutions. Various solution species were determined, and a suitable reaction scheme is suggested(figure 1). We believe that this type of fundamental study is essential for designing new and improved electrolyte solutions for secondary magnesium batteries. Shterenberg, I.; Salama, M.; Yoo, H. D.; Gofer, Y.; Park, J.-B.; Sun, Y.-K.; Aurbach, D. Evaluation of (CF3SO2) 2N−(TFSI) based electrolyte solutions for Mg batteries. J. Electrochem. Soc. 2015 , 162 , A7118-A7128. Salama, M.; Shterenberg, I.; JW Shimon, L.; Keinan-Adamsky, K.; Afri, M.; Gofer, Y.; Aurbach, D. Structural Analysis of Magnesium-Chloride Complexes in Dimethoxyethane Solutions in the Context of Mg Batteries Research. The Journal of Physical Chemistry C 2017 . Figure 1




Salama, M., Shterenberg, I., Gofer, Y., & Aurbach, D. (2018). MgTFSI 2 /MgCl 2  /DME Solution Structure Analysis. ECS Meeting Abstracts, MA2018-01(3), 261–261.

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free