Chloride-Free Electrolyte Based on Tetrabutylammonium Triflate Additive for Extended Anodic Stability in Magnesium Batteries

Chloride-Free Electrolyte Based on Tetrabutylammonium Triflate Additive for Extended Anodic Stability in Magnesium Batteries

Nano Letters

10.1021/acs.nanolett.3c03740

http://dx.doi.org/10.1021/acs.nanolett.3c03740

Deviprasath Chinnadurai, Yuanjian Li, Chang Zhang, Gaoliang Yang, Wei Ying Lieu, Sonal Kumar, Zhenxiang Xing, Wei Liu, Zhi Wei Seh

Batteries

22 November 2023

Chinnadurai, D., Li, Y., Zhang, C., Yang, G., Lieu, W. Y., Kumar, S., Xing, Z., Liu, W., & Seh, Z. W. (2023). Chloride-Free Electrolyte Based on Tetrabutylammonium Triflate Additive for Extended Anodic Stability in Magnesium Batteries. Nano Letters, 23(23), 11233–11242. https://doi.org/10.1021/acs.nanolett.3c03740

Rechargeable magnesium batteries (RMBs) have been proposed as a promising alternative to currently commercialized lithium-ion batteries. However, Mg anode passivation in conventional electrolytes necessitates the use of highly corrosive Cl– ions in the electrolyte. Herein for the first time, we design a chloride-free electrolyte for RMBs with magnesium bis(hexamethyldisilazide) (Mg(HMDS)2) and magnesium triflate (Mg(OTf)2) as the main salts and tetrabutylammonium triflate (TBAOTf) as an additive. The TBAOTf additive improved the dissolution of Mg salts, consequently enhancing the charge-carrying species in the electrolyte. COMSOL studies further revealed desirable Mg growth in our modulated electrolyte, substantiated by homogeneous electric flux distribution across the electrolyte–electrode interface. Post-mortem chemical composition analysis uncovered a MgF2-rich solid electrolyte interphase (SEI) that facilitated exceptional Mg deposition/dissolution reversibility. Our study illustrates a highly promising strategy for synthesizing a corrosion-free and reversible Mg battery electrolyte with a widened anodic stability window of up to 4.43 V.

Publisher Copyright

This research is supported by core funding from: Science and Engineering Research Council
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This research / project is supported by the Agency for Science, Technology and Research (A*STAR) - Central Research Fund
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This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see 10.1021/acs.nanolett.3c03740.

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