The present invention pertains to non-aqueous electrolyte solvents which comprise a non-symmetrical, non-cyclic sulfone and which are suitable for use in secondary electric current producing cells. The present invention also pertains to electrolyte elements comprising such solvents, electric current producing cells comprising such electrolyte elements, and methods for making such electric current producing cells. More particularly, the present invention pertains to electrolyte elements comprising a non-aqueous electrolyte solvent, which solvent comprises a non-symmetrical, non-cyclic sulfone of the general formula R.sup.1 --SO.sub.2 --R.sup.2, wherein R.sup.1 and R.sup.2 are independently linear or branched alkyl or partially or fully fluorinated linear or branched alkyl groups having 1 to 7 carbon atoms, wherein R.sup.1 and R.sup.2 are different, and wherein --SO.sub.2 -- denotes the sulfone group.
Parts of the invention described in this application may have been made with the aid of U.S. government support. As such, the U.S. government may have certain rights in the invention.