TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The electrolytic solution includes non-cyano compounds of formulae (R11-O-C(=O)-O-R12-O-C(=O)-O-R13) (III), (R14-C(=O)-O-(R15-O-)n-C(=O)-R16) (IV) and (R17-S(=O)2-O-R18-O-S(=O)2-R9) (V), and lithium difluorophosphate and dilithium monofluorophosphate. The cyano-group-containing group is one of a group obtained by substituting each of part or all of hydrogen groups in a saturated and unsaturated hydrocarbon group by a cyano group. The halogenated groups comprise one or more of a fluorine group, a chlorine group, a bromine group, and an iodine group. The content of the cyano compound is 0.01-20 wt.% and the non-cyano compound is 0.001-2 wt.%. (I) preferably comprises bis(cyanomethyl) carbonate, 1-cyanoethyl dicyanomethyl carbonate, 1-cyanoethyl phenyl carbonate, cyanomethyl dicyanomethyl carbonate, cyanomethyl phenyl carbonate, cyanomethyl tricyanomethyl carbonate, dicyanomethyl methyl carbonate, methyl tricyanomethyl carbonate, allyl cyanomethyl carbonate, bis(1-cyanoethyl) carbonate, bis(2-cyanoethyl) carbonate, cyanomethyl cyclohexyl carbonate, cyanomethyl prop-2-ynyl carbonate, cyanomethyl vinyl carbonate, (4-cyanophenyl) methyl carbonate, dicyanomethyl methoxy carbonate, dicyanomethyl tricyanomethyl carbonate, bis(tricyanomethyl) carbonate, (cyano(difluoro)methyl) (4-fluorocyclohexyl) carbonate, (cyano(difluoro)methyl) (4-fluorophenyl) carbonate, (cyano(difluoro)methyl) 1,1,3-trifluoroprop-2-ynyl carbonate, (cyano(difluoro)methyl) 1,2,2-trifluorovinyl carbonate, (dicyano(fluoro)methyl) trifluoromethoxy carbonate and (dicyano(fluoro)methyl) trifluoromethyl carbonate. (II) preferably comprises dicyanomethyl propanoate, tricyanomethyl propanoate, 1-cyanoethyl 2-phenylacetate, cyanomethyl but-3-enoate, cyanomethyl 2-phenylacetate, (4-cyanophenyl) 2-phenylacetate, (4-cyanophenyl) propanoate, dicyanomethyl butanoate, dicyanomethyl 3-methylbutanoate, tricyanomethyl butanoate, (cyano(difluoro)methyl) 2,2,3,4,4-pentafluorobut-3-enoate, (cyano(difluoro)methyl) 2,2,3,3,5-pentafluoropent-4-ynoate, cyanomethyl benzoate, cyanomethyl cyclohexanecarboxylate, cyanomethyl 4-fluorobenzoate, cyanomethyl 4-fluorocyclohexanecarboxylate, cyanomethyl pent-4-enoate, cyanomethyl pent-4-ynoate, cyanomethyl trifluoromethyl carbonate, (dicyano(fluoro)methyl) 1,1,2,2,2-pentafluoroethyl carbonate and dicyanomethyl methyl carbonate. (III) preferably comprises butoxycarbonyloxymethyl ethyl carbonate, 2-ethoxycarbonyloxyethyl ethyl carbonate, ethoxycarbonyloxymethyl ethyl carbonate, 4-methoxycarbonyloxybutyl methyl carbonate, 2-methoxycarbonyloxyethyl methyl carbonate, methoxycarbonyloxymethyl methyl carbonate, 3-methoxycarbonyloxypropyl methyl carbonate, 2-propoxycarbonyloxyethyl propyl carbonate, propoxycarbonyloxymethyl propyl carbonate, (CH3-O-C(=O)-O-C2H3F-O-C(=O)-O-CH3), (CH3-O-C(=O)-O-C2H3F2-O-C(=O)-O-CH3) and methyl (1,1,2,2-tetrafluoro-2-methoxycarbonyloxy-ethyl) carbonate. (IV) preferably comprises 3-(2-(2-acetoxyethoxy)ethoxy)propyl butanoate, 2-(2-(3-acetoxypropoxy)ethoxy)ethyl acetate, 2-(2-pentanoyloxyethoxy)ethyl pentanoate, 2-(2-acetoxyethoxy)ethyl acetate, 2-(3-(2-oxopentoxy)propoxy)ethyl butanoate, acetoxymethoxymethoxymethoxymethyl acetate, acetoxymethyl acetate, 3-acetoxypropyl acetate, butanoyloxymethoxymethoxymethoxymethyl butanoate, butanoyloxymethoxymethoxymethyl pentanoate, butanoyloxymethyl butanoate, pentanoyloxymethoxymethoxymethoxymethyl pentanoate, pentanoyloxymethoxymethoxymethyl pentanoate, pentanoyloxymethyl pentanoate, propanoyloxymethyl propanoate and (1,1,2,2-tetrafluoro-2-pentanoyloxy-ethyl) pentanoate. (V) preferably comprises 2-butylsulfonyloxyethyl butane-1-sulfonate, 4-methylsulfonyloxybutyl methanesulfonate, 2-methylsulfonyloxyethyl ethanesulfonate, 2-methylsulfonyloxyethyl methanesulfonate, methylsulfonyloxymethyl methanesulfonate, 3-methylsulfonyloxypropyl methanesulfonate, 2-propylsulfonyloxyethyl propane-1-sulfonate, 2-(2-butylsulfonyloxyethoxy)ethyl butane-1-sulfonate and (2-butylsulfonyloxy-1,1,2,2-tetrafluoro-ethyl) butane-1-sulfonate.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The saturated hydrocarbon group is one of a 1-12C-alkyl group and 3-18C-cycloalkyl group, and the unsaturated hydrocarbon group is one of a 6-18C-aryl group, 2-12C-alkenyl group and 2-12C-alkynyl group. The oxygen-containing saturated hydrocarbon group is 1-12C-alkoxy group. The monovalent hydrocarbon group and the monovalent oxygen-containing hydrocarbon group encompass -12C-alkyl group, 2-12C-alkenyl group, 1-12C-alkynyl group, 6-18C-aryl group, 3-18C-cycloalkyl group and 1-12C-alkoxy group. The divalent hydrocarbon group is one of 1-12C-alkylene group, 2-12C-alkenylene group, 2-12C-alkynylene group, 6-18C-arylene group or 3-18C-cycloalkylene group, where each group is obtained by bonding two or more of the foregoing groups to one another and includes an ether bond (-O-).