TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The content of the cyano cyclic ester carbonate in the electrolytic solution is 0.01-20 wt.%. The electrolytic solution includes one or more diester compound of formulae (R4-O-C(=O)-O-R5-O-C(=O)-O-R6) (II), (R7-C(=O)-O-(R8-O)n-C(=O)-R9) (III) or (R1-S(=O)(=O)-O-R11-O-S(=O)(=O)-R12) (IV), dilithium monofluorophosphate (Li2PFO3) (V), and lithium difluorophosphate (LiPF2O2) (VI). (II) is carbonic acid 2-ethoxycarbonyloxy-ethyl ester ethyl ester, carbonic acid 2-methoxycarbonyloxy-ethyl ester methyl ester, ethoxy-acetic acid ethoxycarbonyloxymethyl ester, carbonic acid 3-methoxycarbonyloxy-propyl ester methyl ester, carbonic acid 4-methoxycarbonyloxy-butyl ester methyl ester, carbonic acid methoxycarbonyloxymethyl ester methyl ester, carbonic acid propoxycarbonyloxymethyl ester propyl ester, carbonic acid butoxycarbonyloxymethyl ester butyl ester, carbonic acid 2-propoxycarbonyloxy-ethyl ester propyl ester, carbonic acid 2-methoxycarbonyloxy-ethyl ester methyl ester, carbonic acid 1-fluoro-2-methoxycarbonyloxy-ethyl ester methyl ester or carbonic acid 1,1-difluoro-2-methoxycarbonyloxy-ethyl ester methyl ester, (III) is one of 17 ester compounds e.g. acetic acid 2-(2-acetoxy-ethoxy)-ethyl ester, butyric acid 2-(2-(1-methylene-butoxy)-ethoxy)-ethyl ester, pentanoic acid 2-(2-(1-methylene-pentyloxy)-ethoxy)-ethyl ester, acetic acid 2-(2-(2-acetoxy-ethoxy)-ethoxy)-ethyl ester, butyric acid 2-(2-(2-butyryloxy-ethoxy)-ethoxy)-ethyl ester, pentanoic acid 2-(2-(2-pentanoyloxy-ethoxy)-ethoxy)-ethyl ester, acetic acid 2-(2-(2-(2-acetoxy-ethoxy)-ethoxy)-ethoxy)-ethyl ester, butyric acid 2-(2-(2-(2-butyryloxy-ethoxy)-ethoxy)-ethoxy)-ethyl ester, pentanoic acid 2-(2-(2-(2-pentanoyloxy-ethoxy)-ethoxy)-ethoxy)-ethyl ester and acetic acid 2-acetoxy-ethyl ester. (IV) is one of methanesulfonic acid 4-methanesulfonyloxy-butyl ester, methanesulfonic acid 2-methanesulfonyloxy-ethyl ester, methanesulfonic acid methanesulfonyloxymethyl ester, methanesulfonic acid 3-methanesulfonyloxy-propyl ester, butane-1-sulfonic acid 2-(butane-1-sulfonyloxy)-ethyl ester, butane-1-sulfonic acid 2-(butane-1-sulfonyloxy)-1,1,2,2-tetrafluoro-ethyl ester, butane-1-sulfonic acid 2-(2-(butane-1-sulfonyloxy)-ethoxy)-ethyl ester. The content of (II) to (VI) in the electrolytic solution is 0.001-2 wt.%.R4, R6, R7, R9, R10, R12 = monovalent hydrocarbon group, monovalent halogenated hydrocarbon group, monovalent oxygen-containing hydrocarbon group or monovalent halogenated oxygen-containing hydrocarbon group;R5, R8, R11 = divalent hydrocarbon group, divalent halogenated hydrocarbon group, divalent oxygen-containing hydrocarbon group or divalent halogenated oxygen-containing hydrocarbon group; andn = greater than 1. SPECIFIC COMPOUNDS - 24 Compounds (I) are specifically claimed, e.g. 5-fluoro-2-oxo-(1,3)dioxolane-4-carbonitrile of formula (Ia), 4-fluoro-2-oxo-(1,3)dioxolane-4,5-dicarbonitrile, 4,5-difluoro-2-oxo-(1,3)dioxolane-4,5-dicarbonitrile, 5-(4-fluoro-phenyl)-2-oxo-(1,3)dioxolane-4-carbonitrile and 5-fluoro-4-methyl-2-oxo-(1,3)dioxolane-4-carbonitrile.