Conductivities and Electrochemical Stabilities of Lithium Salts of Polyfluoroalkoxyaluminate Superweak Anions

Six lithium salts of tris- and tetrakis(polyfluoroalkoxy)aluminate superweak anions have been studied for their potential use as battery electrolytes. Four of the six are based on the formula the other two are and The thermally stable electrolytes and were not oxidized at potentials less than or equal to 5.0 V vs. in dimethoxyethane (DME) or in 50:50% ethylene carbonate:dimethylcarbonate (EC:DMC). The electrolyte was not reduced at 0 V vs. in DME. Neither nor promoted the corrosion of aluminum at 5.0 V vs. The electrolyte underwent efficient, reversible reductive intercalation of with MCMB carbon or electrodes over the potential ranges 0-2 and 2.4-4.8 V, respectively, vs. but did not react in any other way with these electrode materials. The conductivities of some of the electrolytes in DME or in EC:DMC were high enough for them to be considered as potential replacements for in primary and secondary lithium batteries. © 2004 The Electrochemical Society. All rights reserved.