Molecular Design of Mono-Fluorinated Ether-Based Electrolyte for All-Climate Lithium-Ion Batteries and Lithium-Metal Batteries.

Fluorinated-ethers are promising electrolyte solvents in lithium metal batteries, for their high antioxidant and excellent reductive stability on Li anode. However, fluorinated-ethers with high fluorination degree suffer from low ionic conductivity and narrow temperature adaptibility. Herein, we synthesize a mono-fluorinated linear ether of bis(2-fluoroethoxy) methane (BFME) with enhanced solvated ability.

A Fully Methylated Cyclic Ether Solvent Enables Graphite Anode Cycling at Low Temperatures.

Graphite anode suffers from great capacity loss and larger cell polarization under low-temperature conditions in lithium-ion batteries (LIBs), which are mainly caused by the high energy barrier for the Li desolvation process and sluggish Li transfer rate across the solid electrolyte interface (SEI). Regulating an electrolyte with an anion-dominated solvation structure could synchronously stabilize the interface and boost the reaction kinetics of the graphite anode. Herein, a highly ionic conductive electrolyte consisting of a fully methylated cyclic ether solvent of 2,2,4,4,5,5-hexamethyl-1,3-dioxolane (HMD) and fluoroethylene carbonate (FEC) cosolvent was designed.