Nonflammable organic electrolyte solution based on perfluoro-ether solvent for lithium ion batteries

Ethyl nonafluorobutyl ether (EFE) has been used as a co-solvent of nonflammable electrolyte for lithium ion batteries. The charge and discharge performances of graphite negative and lithiated metal oxide (LiCr0.1Mn1.9O4) positive electrodes were examined in the EFE-based electrolyte. High reversible capacity was obtained for the graphite negative electrode but less rechargeability of the metal oxide positive electrode was observed in the EFE-based electrolyte. Addition of a small amount of biphenyl in the electrolyte improved the rechargeability of the oxide. The AC impedance responses proved that the organic additive modifies the properties of the interface between the EFE-based electrolyte and the lithiated metal oxide cathode.