FDMB (2,2,3,3-Tetrafluoro-1,4-Dimethoxybutane, >99.0%) as Battery Electrolyte Co-Solvent and Additive, 5-25 g/bottle, CBESAFDMB

2,2,3,3-Tetrafluoro-1,4-dimethoxybutane (commonly designated as FDMB or fluorinated 1,4-dimethoxybutane) is a specialized fluorinated ether derivative engineered as an advanced solvent, co-solvent, and interphase-directing additive for next-generation lithium-metal, anode-free, and lithium-sulfur batteries. By incorporating strategic perfluoroalkylene segments (-CF2CF2-) into a traditional glyme-like backbone, FDMB bridges the high-solvation advantages of linear ethers with the exceptional electrochemical stability and safety profile of fluorinated media.

Its main functional roles in electrolyte engineering are: (1) Solvation Sheath Modulation & Anion Coordination: FDMB modifies the primary lithium-ion solvation shell, discouraging aggressive solvent-separated ion pairing and encouraging beneficial anion incorporation (such as with LiFSI salts) into the inner coordination sphere. (2) Robust Anode Passivation (SEI Engineering): Due to its tailored reduction potential, FDMB preferentially decomposes during initial electrochemical formation steps. This reductive pathway yields a dense, inorganic-rich Solid Electrolyte Interphase (SEI) heavily enriched with lithium fluoride (LiF), which isolates the reactive lithium surface and inhibits dendrite proliferation. (3) Polysulfide Trapping (Lithium-Sulfur Systems): The polar fluorinated structure exhibits strong binding affinity toward lithium polysulfides, effectively suppressing the destructive polysulfide shuttle phenomenon in high-energy sulfur cathodes. (4) Intrinsic Flame Retardancy: The dense fluorine content significantly enhances thermal stability and suppresses vapor-phase radical propagation, drastically lowering the flammability risk compared to conventional carbonate or volatile ether electrolytes.  

Its main electrochemical applications are: (1) High-Performance Lithium-Metal & Anode-Free Cells: Paired with salts like lithium bis(fluorosulfonyl)imide (LiFSI) to enable highly reversible stripping/plating behavior, driving Coulombic efficiencies past 99.5% in half-cells and unlocking practical anode-free pouch cell configurations. (2) Advanced Lithium-Sulfur (Li-S) Batteries: Deployed as a primary co-solvent to maintain high specific discharge capacity near theoretical limits while achieving exceptional long-term cycle retention.

Part Number	CBESAFDMB (C-BESA-FDMB)
CAS	2738080-99-2
Chemical Formula	C₆H₁₀F₄O₂
Appearance	Colorless Liquid
Purity	>99.0% (Battery Grade)
Molecular Weight	190.14 g/mol
Package Size	5 g, 10 g, and 25 g/bottle

Notes: Please store the FDMB in the glovebox due to its sensitivity to humidity and oxygen. 

References: 

1. M. W. Hasan, et al. A Synergistic Strategy for the Development of Advanced, Scalable Lithium–Sulfur Batteries, ACS Appl. Mater. Interfaces (2025) 17 (34): 48209–48219.
2. X. Zhu, et al. Molecular Engineering of Electrolyte Solvents for Lithium Metal Batteries: Strategies, Challenges, and Prospects, Batteries & Supercaps, 2025, 8, e202500246