New functionalized ionic liquids (ILs), comprised of multi-methoxyethyl substituted quaternary ammonium cations (i.e. [N(CH2CH2OCH3)4−n (R) n ]+; n =1, R=CH3OCH2CH2; n =1, R=CH3, CH2CH3; n =2, R=CH3CH2), and two representative perfluorinated sulfonimide anions (i.e. bis(fluorosulfonyl)imide (FSI−) and bis(trifluoromethanesulfonyl)imide (TFSI−)), were prepared. Their fundamental properties, including phase transition, thermal stability, viscosity, density, specific conductivity and electrochemical window, were extensively characterized. These multi-ether functionalized ionic liquids exhibit good capability of dissolving lithium salts. Their binary electrolytes containing high concentration of the corresponding lithium salt ([Li+] >1.6molkg−1) show Li+ ion transference number ( t L i + ) as high as 0.6–0.7. Their electrochemical stability allows Li deposition/stripping realized at room temperature. The desired properties of these multi-ether functionalized ionic liquids make them potential electrolytes for Li (or Li-ion) batteries.