F4DEE {1,2-Bis(2,2-difluoroethoxy)ethane, >99.0%} as Battery Electrolyte Co-Solvent and Additive, 5-25 g/bottle, CBESAF4DEE

F4DEE (1,2-bis(2,2-difluoroethoxy)ethane) is a high-purity, linear fluorinated ether solvent and co-solvent engineered specifically for advanced next-generation energy storage systems. By incorporating terminal 2,2-difluoroethoxy groups onto a central ethylene glycol diether backbone, F4DEE provides an exceptional balance of oxidative stability, ionic transport, and interphase-directing capability for lithium-metal and lithium-sulfur batteries.

Its functional roles in electrolyte engineering are: (1) Robust Solid Electrolyte Interphase (SEI) Passivation: Due to its tailored reduction potential, F4DEE preferentially decomposes during initial electrochemical cycling to assist in building a dense, inorganic-rich SEI layer heavily enriched with lithium fluoride (LiF) on lithium metal anodes, effectively suppressing dendrite propagation and dead lithium accumulation. (2) Enhanced Oxidative and High-Voltage Stability: The electron-withdrawing inductive effect of the terminal fluorine atoms lowers the Highest Occupied Molecular Orbital (HOMO) energy level, elevating the anodic stability threshold and preventing premature electrolyte oxidation. (3) Optimized Polysulfide Solubility: In sulfur-based systems, F4DEE exhibits a moderate dissolving power toward lithium polysulfide (LiPS) intermediates, helping contain the polysulfide shuttle effect while maintaining active reaction kinetics. (4) Localized High-Concentration Electrolyte (LHCE) Integration: When deployed as a co-solvent or diluent, F4DEE lowers bulk viscosity and enhances separator wettability without disrupting the primary ion-solvent coordination clusters characteristic of concentrated systems.

Part Number	CBESAF4DEE (C-BESA-F4DEE)
CAS	1691328-94-5
Chemical Formula	C6H10F4O2
Appearance	Colorless liquid
Purity	>99.0%
Molecular Weight	190.14 g/mol
Density	1.17 g/mL at 25 °C
Boiling Point	172.8 °C
Package Size	5 g, 10 g, and 25 g/bottle

Notes: Please store the F4DEE liquid in the dry place (glovebox is the best).

References: 

1. J. Yang, et al. Tailoring Electrolytes by Decoupling the Roles of Li+ and Lithium Polysulfides in Li–S Batteries, ACS Energy Lett. (2025) 10 (11): 5674–5683.
2. R. Jayakumar, et al. Ethylene sulfate-enabled stable interphases in fluorinated ether electrolytes for high-performance sodium-ion batteries, Journal of Power Sources, 2026, 662, 238753