TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The cathode electrode comprises carbon-based material and/or silicon-based material as anode active material. The carbon-based material is chosen from crystalline artificial graphite, crystalline natural graphite, amorphous hard carbon, crystalline soft carbon, carbon black, acetylene black, Ketchen Black (RTM: superconductive carbon black), Super P (RTM: conductive carbon black), graphene and carbon fibers. The electrolyte solution comprises lithium salt and nonaqueous solvent. The secondary battery contains anode containing lithium-transition metal oxide complex of formula: Lix1My1Mn2-y1O4-z1Az1 or (1-x)LiM'O2-y'2A'y'2-xLi2MnO3-y2A'y2, as anode active material, where M' is MnaMb, a+b is 1, x1 is 0.9-1.2, y1 is more than 0 to less than 2, z1 is 0 to less than 0.2, M is aluminum, magnesium, nickel, cobalt, iron, chromium, vanadium, titanium, copper, boron, calcium, zinc, zirconium, niobium, molybdenum, strontium, antimony, tungsten, titanium or bismuth, A is monovalent anion, x is more than 0 to less than 1, y'2 and y2 are more than 0 to 0.02, a is 0.5-1, b is 0-0.5 and A' is phosphate ion, borate ion, carbonate ion, fluoride ion or nitrate ion.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The lithium salt is chosen from lithium chloride, lithium bromide, lithium perchlorate, lithium tetrafluoroborate, lithium hexafluorophosphate, lithium trifluoromethanesulfonate, lithium triflate, lithium hexafluoroarsenate, lithium hexafluoroantimonate, lithium tetrachloroaluminate, lithium methanesulfonate, lithium trifluoromethanesulfonate and lithium bis(trifluoromethane)sulfonamide. The nonaqueous solvent is carbonate-based solvent and/or ester solvent. The electrolyte solution further includes additive chosen from vinylene carbonate, vinyl ethylene carbonate, fluoroethylene carbonate, salicylic acid, lithium tetrafluoroborate, lithium bis(trifluoromethylsulfonimide), lithium bis(oxalato)borate and lithium difluoro(oxalato)borate.    TECHNOLOGY FOCUS - POLYMERS - Preferred Composition: The separation film is nonwoven fabric or olefin-based porous polymer sheet.