Co-Intercalation-Free Ether-Based Weakly Solvating Electrolytes Enable Fast-Charging and Wide-Temperature Lithium-Ion Batteries

Ether-based electrolytes are competitive choices to meet the growing requirements for fast-charging and low-emperature lithium-ion batteries (LIBs) due to the low viscosity and low melting point of ether solvents. Unfortunately, the graphite (Gr) electrode is incompatible with commonly used ether solvents due to their irreversible co-intercalation into Gr interlayers. Here, we propose cyclopentyl methyl ether (CPME) as a co-intercalation-free ether solvent, which contains a cyclopentane group with large steric hindrance to obtain weakly solvating power with Li+ and a wide liquid-phase temperature range (-140 to +106 degrees C). A weakly solvating electrolyte ( WSE) based on CPME and fluoroethylene carbonate (FEC) cosolvents can simultaneously achieve fast desolvation ability and high ionic conductivity, which also induces a LiF-rich solid electrolyte interphase (SEI) on the Gr anode. Therefore, the Gr/Li half-cell with this WSE can deliver outstanding rate capability, stable cycling performance, and high specific capacity (319 mAh g(-1)) at an ultralow temperature of -60 degrees C. Furthermore, a practical LiFePO4 (loading approximate to 25 mg cm(-2))/Gr (loading approximate to 12 mg cm(-2)) pouch cell with this WSE also reveals outstanding rate capability and stable long-term cycling performance above 1000 cycles with a high Coulombic efficiency (approximate to 99.9%) and achieves an impressive lowtemperature application potential at -60 degrees C.