TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises (a) reacting difluorofluorosulfonylacetylfluoride with triethylamine trihydrofluoride or tetramethylammoniumfluoride to form triethylammonium-2-sulfonyl-tetrafluoroethanolate or tetramethylammonium-2-sulfonyl-tetrafluoroethanolate, (b) methylating triethylammonium-2-sulfonyl-tetrafluoroethanolate or tetramethylammonium-2-sulfonyl-tetrafluoroethanolate to form 2-methoxy-1,1,2,2-tetrafluoro-ethanesulfonylfluoride and (c) reacting 2-methoxy-1,1,2,2-tetrafluoro-ethanesulfonylfluoride with lithium hydroxide.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The electrolyte comprises an aprotic solvent, an ionic liquid and/or a polymer matrix. The aprotic solvent is ethylene carbonate, diethyl carbonate, dimethyl carbonate (all preferred), propylene carbonate, ethylmethyl carbonate, acetonitrile, glutaronitrile, adiponitrile, pimelonitrile, gamma -butyrolactone, gamma -valerolactone, dimethoxyethane, 1,3-dioxalane and/or methyl acetate. The aprotic solvent comprises a mixture of ethylene carbonate and at least one further aprotic solvent, preferably diethyl comprises in a ratio of 1:9-9:1, preferably 3:7-1:1. The concentration of (I) in the electrolyte is 0.5-2.5, preferably 1-1.5M. EXAMPLE - Triethylamine (21 mmole) and triethylamine trihydrofluoride (11 mmole) were dissolved in dry dichloromethane (20 ml). The obtained solution was treated with liquid nitrogen at -196 degrees C and condensed with difluorofluorosulfonyl-acetyl (32 mmole). The reaction mixture was stirred for 3 hours at 20 degrees C to obtain triethylammonium-2-sulfonyl-tetrafluoroethanolate. Triethyl-2-sulfonyl-tetrafluoroethanolate (32 mmole) was dissolved in dry 2,2'-dimethoxydiethylether (20 ml). At 0 degrees C, dimethylsulfate (39 mmole) was added slowly. The reaction mixture was heated at 50 degrees C for 7 hours. The obtained product was fractionally distilled at under normal pressure to obtain 2-methoxy-1,1,2,2-tetrafluoro-ethanesulfonylfluoride. 2-Methoxy-1,1,2,2-tetrafluoro-ethanesulfonylfluoride (21 mmole) was dissolved in methanol. At 0 degrees C, 2N equivalent of lithium hydroxide was added. The suspension was stirred for 2 hours at room temperature and centrifuged for 15 minutes. The liquid phase was decanted and the solvent was deducted. The product was vacuum dried at 60 degrees C for 6 hours to obtain lithium-2-methoxy-1,1,2,2-tetrafluoro-ethane sulfonate in the form of white crystals.