TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The content of the chlorine ions is less than or equal to 50 wt.ppm. (I) is at least one of (1,2,5)oxadithiolane 2,2,5,5-tetraoxide, (1,2,6)oxadithiane 2,2,6,6-tetraoxide, (1,2,7)oxadithiepane 2,2,7,7-tetraoxide, 3-methyl-(1,2,5)oxadithiolane 2,2,5,5-tetraoxide, 3,4-dimethyl-(1,2,5)oxadithiolane 2,2,5,5-tetraoxide, 3-fluoro-(1,2,5)oxadithiolane 2,2,5,5-tetraoxide, 3,3,4,4-tetrafluoro-(1,2,5)oxadithiolane 2,2,5,5-tetraoxide, 4-methyl-(1,2,6)oxadithiane 2,2,6,6-tetraoxide, 4-fluoro-(1,2,6)oxadithiane 2,2,6,6-tetraoxide, 3,3,4,4,5,5-hexafluoro-(1,2,6)oxadithiane 2,2,6,6-tetraoxide, (1,2,5)oxadithiole 2,2,5,5-tetraoxide, 3H-(1,2,6)oxadithiane 2,2,6,6-tetraoxide, 3-methyl-(1,2,5)oxadithiolane 2,2,5,5-tetraoxide, 4-methyl-(1,2,6)oxadithiane 2,2,6,6-tetraoxide, benzo(1,2,5)oxadithiole 1,1,3,3-tetraoxide, 5-fluoro-benzo(1,2,5)oxadithiole 1,1,3,3-tetraoxide, 5,6-difluoro-benzo(1,2,5)oxadithiole 1,1,3,3-tetraoxide, 4-fluoro-benzo(1,2,5)oxadithiole 1,1,3,3-tetraoxide or 4-oxa-3,5-dithia-tricyclo(5.2.1.0asterisk2,6asterisk)dec-8-ene 3,3,5,5-tetraoxide, and (II) is at least one of 2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathiolan-5-one, 2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathian-6-one, 2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathiepan-7-one, 2,2-dioxo-2H-2 lambda asterisk6asterisk-(1,2)oxathiol-5-one, 2,2-dioxo-2,5-dihydro-2 lambda asterisk6asterisk-(1,2)oxathiin-6-one, 3-methyl-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathiolan-5-one, 4-methyl-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathiolan-5-one, 3,4-dimethyl-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathiolan-5-one, 3-fluoro-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathiolan-5-one, 3,3,4,4-tetrafluoro-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathiolan-5-one, 4-fluoro-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathian-6-one, 3,3,4,4,5,5-hexafluoro-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathian-6-one, 4-methyl-2,2-dioxo-2 lambda asterisk6asterisk-(1,2)oxathian-6-one, 4-methyl-2,2-dioxo-2,5-dihydro-2 lambda asterisk6asterisk-(1,2)oxathiin-6-one or 3,3-dioxo-4-oxa-3 lambda asterisk6asterisk-thia-tricyclo(5.2.1.0asterisk2,6asterisk)dec-8-en-5-one. The content of the sulfonic acid anhydride in the non-aqueous solvent is 0.001-5 wt.%. The anode contains a carbon material, lithium metal or a material that is able to insert and extract lithium ion and that has at least one of a metal element and a metalloid element as an element as an anode active material. The anode contains a material having silicon and/or tin as an element as an anode active material. Preferred Definitions:    X, Y1 = optionally branched 2-4C alkylene, optionally branched 2-4C alkenylene, arylene or their derivatives.    EXAMPLE - Lithium hexafluorophosphate was dissolved in mixture of ethylene carbonate and dimethyl carbonate (30:70 weight ratio). Then sulfonic acid anhydride was added to the reaction mixture to obtain electrolytic solution having 50 ppm of chloride ions.