Electrolytic solvents and applications of such solvents including electric current-producing devices. For example, a solvent can include a sulfone compound of R.sup.1--SO.sub.2--R.sup.2, with R.sup.1 being an alkyl group and R.sup.2 a partially oxygenated alkyl group, to exhibit high chemical and thermal stability and high oxidation resistance. For another example, a battery can include, between an anode and a cathode, an electrolyte which includes ionic electrolyte salts and a non-aqueous electrolyte solvent which includes a non-symmetrical, non-cyclic sulfone. The sulfone has a formula of R.sup.1--SO.sub.2--R.sup.2, wherein R.sup.1 is a linear or branched alkyl or partially or fully fluorinated linear or branched alkyl group having 1 to 7 carbon atoms, and R.sup.2 is a linear or branched or partially or fully fluorinated linear or branched oxygen containing alkyl group having 1 to 7 carbon atoms. The electrolyte can include an electrolyte co-solvent and an electrolyte additive for protective layer formation.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 The U.S. Government has a paid-up license in the present invention and the right in limited circumstances to require the patent owner to license others on fair and reasonable terms as provided by the terms of Grant No. DEFG039ER14378-003 and DEFG03945541 awarded by the U.S. Department of Energy.