TTE (1,1,2,2-Tetrafluoroethyl 2,2,3,3-tetrafluoropropylether, >99.95%) as Battery Electrolyte Co-Solvent, 50-200 g/bottle, CBESTTE

TTE (1,1,2,2-Tetrafluoroethyl 2,2,3,3-tetrafluoropropylether, or HFE-458), is a symmetrical, hydrofluoroether (HFE) used as a non-solvating fluorinated diluent / co-solvent in localized high-concentration electrolytes (LHCEs) and high-voltage, wide-temperature battery formulations. Its highly fluorinated aliphatic structure gives it extremely low donor power, high oxidation resistance, low viscosity, and high non-flammability.

Non-Solvating Diluent in LHCE Systems: Similar to BTFE, TTE serves as a classic diluent in Localized High-Concentration Electrolyte (LHCE) designs: (1) Preservation of Solvation Structures: Because of the strong electron-withdrawing fluorinated tails on both sides of the ether bridge, TTE exhibits negligible donor ability (low Gutmann Donor Number). It does not dissolve lithium salts directly and stays outside the primary Li+ solvation sheath. (2) Viscosity & Conductivity Optimization: Adding TTE to an ultra-high-concentration salt-in-solvent mixture (e.g., 4M LiFSI in DME or trimethyl phosphate) lowers bulk viscosity and improves wetting and wettability of thick porous electrodes without disrupting the beneficial Contact Ion Pair (CIP) and Aggregate (AGG) solvation clusters.

Highly Inorganic LiF-Rich Interphase Construction: Under reductive potentials at the lithium-metal or graphite anode, TTE undergoes sacrificial decomposition to form an inorganic-rich Solid Electrolyte Interphase (SEI) dominated by lithium fluoride (LiF). LiF provides high interfacial energy against metallic lithium, preventing dendrite propagation and suppressing continuous electrolyte consumption during extended cycling. 

Wide Electrochemical Stability & Flame Retardancy: (1) Anodic Oxidation Limit: TTE exhibits a low Highest Occupied Molecular Orbital (HOMO) energy level, expanding the oxidative stability window of ether-based electrolytes beyond 4.5-5.0 V vs. Li/Li+. This allows high-voltage cathodes (such as NMC811, NMC955, or LCO) to operate stably in ether-rich environments. (2) Safety: TTE possesses a high flash point and strong flame-retardant characteristics, significantly reducing thermal runaway risks.

Part Number	CBESTTE (C-BES-TTE)
CAS	16627-68-2
Chemical Formula	C5H4F8O
Appearance	Colorless Liquid
Purity	>99.95%
Molecular Weight	232.07 g/mol
Density	1.54 g/mL
Boling Point	92 °C
Package Size	50 g, 100 g, and 200 g/bottle

Notes: Please store the TTE solvent in the glovebox due to its sensitivity to humidity and oxygen 

References: 

1. D. Ouyang, et al. An all-fluorinated electrolyte with 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropylether as co-solvent for lithium-ion cells with advanced electrochemical and safety properties at high voltage, J. Power Sources, 2024, 615, 235095.
2. D. Ouyang, et al. A 1,1,2,3,3,3-hexafluoropropyl 2,2,2-trifluoroethyl ether diluted all-fluorinated electrolyte for outstanding high-voltage lithium-ion cells, Chem. Engineering J., 2025, 524, 169568.