Coulombic liquid-liquid phase separation of dilithium hexafluoropropane-1,3-bis[sulfonylbis(trifluoromethylsulfonyl)methanide] solutions in diethylcarbonate

Coulombic liquid-liquid phase separation, which is known for several tetraa lkylammonium salt solutions, may also take place in various battery electro lytes and thereby prevent their use in electrochemical cells, especially wh en 2:1 salts in low-dielectric-constant solvents are considered. We report here on such a phase separation for dilithium hexafluoropropane-1,3-bis[sul fonylbis(trifluoromethylsulfonyl)methanide] solutions in diethyl carbonate which shows a highly asymmetric phase diagram. The critical exponent is in accordance with nonclassical (Ising) behavior. (C) 1999 The Electrochemical Society. S1099-0062(98)12-076-X. All rights reserved.