TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - The positive-electrode current collector comprises any one of aluminum, and/or titanium. The positive-electrode active material comprises any one of a metal compound having a layered structure, activated carbon, and a lithium-containing composite oxide. The negative-electrode current collector comprises any one of copper, aluminum, nickel, and/or titanium. The negative-electrode active material comprises any one of carbon material, silicon material, and silicon alloy material. The first insulator and the second insulator comprises at least one of acrylic resin, polyimide resin, polyimide amide resin, phenol resin, epoxy resin, resist, silicon oxide, silicon oxide containing nitrogen, silicon nitride containing oxygen, and silicon nitride.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - The solvent of the electrolyte includes any one of cyclic carbonate, ethylene carbonate, propylene carbonat, butylene carbonate, vinylene carbonate, acyclic carbonate, dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, methylpropyl carbonate, methylisobutyl carbonate, dipropyl carbonate, aliphatic carboxylic acid ester, methyl formate, methyl acetate, methyl propionate, ethyl propionate, gamma -lactones, gamma -butyrolactone, acyclic ether, 1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxy ethane, cyclic ether, tetrahydrofuran, 2-methyltetrahydrofuran, dimethylsulfoxide, 1,3-dioxolane, alkyl phosphate ester, trimethyl phosphate, triethyl phosphate, and trioctyl phosphate and/or fluorides.    TECHNOLOGY FOCUS - POLYMERS - The separator includes any one of cellulose, paper, nonwoven fabric, glass fiber, nylon, polyamide, vinylon, polyester, acrylic, polyolefin, polyurethane, fluorine-based polymer, polyethylene, polypropylene, polyethylene oxide, polypropylene oxide, polyacrylonitrile, polyvinylidene chloride, polymethyl methacrylate, polymethylacrylate, polyvinyl alcohol, polymethacrylonitrile, polyvinyl acetate, polyvinylpyrrolidone, polyethyleneimine, polybutadiene, polystyrene, polyisoprene, and/or its derivatives.