TY - JOUR
T1 - Reversible Zinc Electrodeposition at −60 °C Using a Deep Eutectic Electrolyte for Low-Temperature Zinc Metal Batteries
AU - Hawkins, Brendan E.
AU - Schoetz, Theresa
AU - Gordon, Leo W.
AU - Kt, Surabh
AU - Wang, Jonah
AU - Messinger, Robert J.
N1 - Publisher Copyright:
© 2023 American Chemical Society.
PY - 2023/3/9
Y1 - 2023/3/9
N2 - Rechargeable zinc (Zn) metal batteries are attractive for use as electrochemical energy storage systems on a global scale because of the low cost, high energy density, inherent safety, and strategic resource security of Zn metal. However, at low temperatures, Zn batteries typically suffer from high electrolyte viscosity and unfavorable ion transport properties. Here, we studied reversible Zn electrodeposition in mixtures of 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ([EMIm]TFSI) ionic liquid, γ-butyrolactone (GBL) organic solvent, and Zn(TFSI)2 zinc salt. The electrolyte mixtures enabled reversible Zn electrodeposition at temperatures as low as −60 °C. An electrolyte composed of 0.1 M Zn(TFSI)2 in [EMIm]TFSI:GBL with a volume ratio of 1:3 formed a deep eutectic solvent that optimized electrolyte conductivity, viscosity, and the zinc diffusion coefficient. Liquid-state 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and molecular dynamic (MD) simulations indicate increased formation of contact ion pairs and the reduction of ion aggregates are responsible for the optimal composition.
AB - Rechargeable zinc (Zn) metal batteries are attractive for use as electrochemical energy storage systems on a global scale because of the low cost, high energy density, inherent safety, and strategic resource security of Zn metal. However, at low temperatures, Zn batteries typically suffer from high electrolyte viscosity and unfavorable ion transport properties. Here, we studied reversible Zn electrodeposition in mixtures of 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)imide ([EMIm]TFSI) ionic liquid, γ-butyrolactone (GBL) organic solvent, and Zn(TFSI)2 zinc salt. The electrolyte mixtures enabled reversible Zn electrodeposition at temperatures as low as −60 °C. An electrolyte composed of 0.1 M Zn(TFSI)2 in [EMIm]TFSI:GBL with a volume ratio of 1:3 formed a deep eutectic solvent that optimized electrolyte conductivity, viscosity, and the zinc diffusion coefficient. Liquid-state 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and molecular dynamic (MD) simulations indicate increased formation of contact ion pairs and the reduction of ion aggregates are responsible for the optimal composition.
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U2 - 10.1021/acs.jpclett.3c00150
DO - 10.1021/acs.jpclett.3c00150
M3 - Article
C2 - 36848484
AN - SCOPUS:85149992319
SN - 1948-7185
VL - 14
SP - 2378
EP - 2386
JO - Journal of Physical Chemistry Letters
JF - Journal of Physical Chemistry Letters
IS - 9
ER -