Alkoxyethyl Acetate Electrolytes for High‐Voltage Lithium Metal Batteries
6 affiliations
- 1Chemical Sciences and Engineering Division Argonne National Laboratory Lemont Illinois USA
- 2Nanoscience and Technology Division Argonne National Laboratory Lemont Illinois USA
- 3Department of Chemical and Biological Engineering Northwestern University Evanston Illinois USA
- 4General Motors Global Research and Development Center Warren Michigan USA
- 5SUNCAT Center for Interface Science and Catalysis, Department of Chemical Engineering Stanford University Stanford California USA
- 6Materials Science Division Argonne National Laboratory Lemont Illinois USA
Abstract
High‐energy‐density lithium metal batteries (LMBs) require electrolytes that can simultaneously support stable lithium metal anodes and high‐voltage cathodes such as NMC811 operated up to 4.5 V. Here, a molecular engineering strategy is introduced in which a carbonyl group and a trifluoromethyl group are incorporated into a glycol‐ether‐type backbone to produce a fluorinated alkoxyethyl acetate solvent, 2‐(2,2,2‐trifluoroethoxy)ethyl acetate (TFE‐EA), used as the main solvent in LiFSI–TFE‐EA–FEC electrolytes. This design breaks the symmetric bidentate solvation typical of ether solvents, establishes carbonyl‐dominant solvation, and depresses the solvating ability and oxidation reactivity of the ethereal oxygen, as revealed by combined DFT, NMR, FTIR, Raman, and AIMD analyses. The resulting TFE‐EA‐based electrolyte exhibits enhanced oxidative stability, improved lithium plating/stripping efficiency, dense and uniform lithium deposition, and robust cathode–electrolyte interphases in Li||NMC811 cells cycled to 4.5 V, delivering markedly superior capacity retention and Coulombic efficiency compared with ethereal counterparts. Parallel studies on the non‐fluorinated alkoxyethyl acetate MEA and its ether analog EME confirm that ester introduction alone improves oxidative stability and cycling, while fluorination further amplifies these benefits. This work establishes alkoxyethyl acetates, exemplified by TFE‐EA, as a promising solvent platform for practical, high‐voltage LMB electrolytes.
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BibTeX
@article{li2026alkoxyethyl,
title = {{Alkoxyethyl Acetate Electrolytes for High‐Voltage Lithium Metal Batteries}},
author = {Xinlin Li and Xianyang Wu and Xueping Qin and Sapna L. Ramesh and Hasnain Hafiz and Jeffrey Lopez and Changzhi Ai and Matthew Li and Rachid Amine and Meinan He and Chi‐Cheung Su and Khalil Amine},
journal = {Angewandte Chemie (International Ed. in English)},
year = {2026},
month = sep,
doi = {10.1002/anie.2561729},
url = {https://doi.org/10.1002/anie.2561729},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Alkoxyethyl Acetate Electrolytes for High‐Voltage Lithium Metal Batteries
AU - Xinlin Li
AU - Xianyang Wu
AU - Xueping Qin
AU - Sapna L. Ramesh
AU - Hasnain Hafiz
AU - Jeffrey Lopez
AU - Changzhi Ai
AU - Matthew Li
AU - Rachid Amine
AU - Meinan He
AU - Chi‐Cheung Su
AU - Khalil Amine
PY - 2026
DA - 2026/09/22
JO - Angewandte Chemie (International Ed. in English)
DO - 10.1002/anie.2561729
UR - https://doi.org/10.1002/anie.2561729
AB - High‐energy‐density lithium metal batteries (LMBs) require electrolytes that can simultaneously support stable lithium metal anodes and high‐voltage cathodes such as NMC811 operated up to 4.5 V. Here, a molecular engineering strategy is introduced in which a carbonyl group and a trifluoromethyl group are incorporated into a glycol‐ether‐type backbone to produce a fluorinated alkoxyethyl acetate solvent, 2‐(2,2,2‐trifluoroethoxy)ethyl acetate (TFE‐EA), used as the main solvent in LiFSI–TFE‐EA–FEC electrolytes. This design breaks the symmetric bidentate solvation typical of ether solvents, establishes carbonyl‐dominant solvation, and depresses the solvating ability and oxidation reactivity of the ethereal oxygen, as revealed by combined DFT, NMR, FTIR, Raman, and AIMD analyses. The resulting TFE‐EA‐based electrolyte exhibits enhanced oxidative stability, improved lithium plating/stripping efficiency, dense and uniform lithium deposition, and robust cathode–electrolyte interphases in Li||NMC811 cells cycled to 4.5 V, delivering markedly superior capacity retention and Coulombic efficiency compared with ethereal counterparts. Parallel studies on the non‐fluorinated alkoxyethyl acetate MEA and its ether analog EME confirm that ester introduction alone improves oxidative stability and cycling, while fluorination further amplifies these benefits. This work establishes alkoxyethyl acetates, exemplified by TFE‐EA, as a promising solvent platform for practical, high‐voltage LMB electrolytes.
SN - 1433-7851
SN - 1521-3773
ER -