Stable lithium/electrolyte interphase enabled by tailoring Li+ solvation structure and FEC additive in LiOTf/LiNO3 dual-salt sulfolane-based nonflammable electrolyte for lithium metal batteries
Abstract
Developing nonflammable electrolytes with stable lithium-metal interfaces and reversible Li plating/stripping remains a critical challenge for lithium metal batteries. Herein, a sulfolane-based nonflammable electrolyte containing lithium trifluoromethanesulfonate (LiOTf), lithium nitrate (LiNO 3 ) and fluoroethylene carbonate (FEC) is developed by regulating Li + solvation and interfacial chemistry. NMR spectroscopy and ab initio molecular dynamics simulations reveal that partial substitution of LiOTf with LiNO 3 redistributes the first Li + solvation shell, reducing sulfolane coordination while increasing anion participation. Raman and FT-IR analyses further indicate that FEC modifies the local interaction network among electrolyte components. The optimized Li[OTf/NO 3 ]-FEC electrolyte exhibits a low viscosity of 34.4 cP, an ionic conductivity of 0.63 mS cm −1 and favorable self-extinguishing behavior. FEC also promotes an inorganic-rich SEI containing LiF, Li 3 N, LiN x O y , Li 2 O, Li 2 SO 4 and Li 2 SO 3 , resulting in lower interfacial resistance and more uniform Li deposition. Consequently, Li//Li cells exhibit an overpotential of ∼0.12 V and stable cycling for ∼270 h at 0.5 mA cm −2 and 0.5 mAh cm −2 , while Li//Cu cells maintain 97–98% Coulombic efficiency for over 100 cycles with an average efficiency of 96.48% by the modified Aurbach method. Li//LiMn 2 O 4 cells retain 85.7% capacity after 587 cycles at 100 mA g −1 and 67.2% after 1600 cycles at 500 mA g −1 . These results demonstrate that combining Li + solvation regulation with FEC-assisted interphase engineering is an effective strategy for stable, nonflammable lithium metal batteries.
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BibTeX
@article{pan2026stable,
title = {{Stable lithium/electrolyte interphase enabled by tailoring Li+ solvation structure and FEC additive in LiOTf/LiNO3 dual-salt sulfolane-based nonflammable electrolyte for lithium metal batteries}},
author = {Chun-Jern Pan and Yi-Yu Chen and Jia-He Peng and Jia-Yun Jhang and Li-Ying Yu},
journal = {Electrochemistry Communications},
year = {2026},
month = oct,
doi = {10.1016/j.elecom.2026.108266},
url = {https://linkinghub.elsevier.com/retrieve/pii/S1388248126001621},
note = {CC BY-NC 4.0},
}
RIS
TY - JOUR
TI - Stable lithium/electrolyte interphase enabled by tailoring Li+ solvation structure and FEC additive in LiOTf/LiNO3 dual-salt sulfolane-based nonflammable electrolyte for lithium metal batteries
AU - Chun-Jern Pan
AU - Yi-Yu Chen
AU - Jia-He Peng
AU - Jia-Yun Jhang
AU - Li-Ying Yu
PY - 2026
DA - 2026/10/30
JO - Electrochemistry Communications
DO - 10.1016/j.elecom.2026.108266
UR - https://linkinghub.elsevier.com/retrieve/pii/S1388248126001621
AB - Developing nonflammable electrolytes with stable lithium-metal interfaces and reversible Li plating/stripping remains a critical challenge for lithium metal batteries. Herein, a sulfolane-based nonflammable electrolyte containing lithium trifluoromethanesulfonate (LiOTf), lithium nitrate (LiNO 3 ) and fluoroethylene carbonate (FEC) is developed by regulating Li + solvation and interfacial chemistry. NMR spectroscopy and ab initio molecular dynamics simulations reveal that partial substitution of LiOTf with LiNO 3 redistributes the first Li + solvation shell, reducing sulfolane coordination while increasing anion participation. Raman and FT-IR analyses further indicate that FEC modifies the local interaction network among electrolyte components. The optimized Li[OTf/NO 3 ]-FEC electrolyte exhibits a low viscosity of 34.4 cP, an ionic conductivity of 0.63 mS cm −1 and favorable self-extinguishing behavior. FEC also promotes an inorganic-rich SEI containing LiF, Li 3 N, LiN x O y , Li 2 O, Li 2 SO 4 and Li 2 SO 3 , resulting in lower interfacial resistance and more uniform Li deposition. Consequently, Li//Li cells exhibit an overpotential of ∼0.12 V and stable cycling for ∼270 h at 0.5 mA cm −2 and 0.5 mAh cm −2 , while Li//Cu cells maintain 97–98% Coulombic efficiency for over 100 cycles with an average efficiency of 96.48% by the modified Aurbach method. Li//LiMn 2 O 4 cells retain 85.7% capacity after 587 cycles at 100 mA g −1 and 67.2% after 1600 cycles at 500 mA g −1 . These results demonstrate that combining Li + solvation regulation with FEC-assisted interphase engineering is an effective strategy for stable, nonflammable lithium metal batteries.
SN - 1388-2481
SN - 1873-1902
ER -