TECHNOLOGY FOCUS - CERAMICS AND GLASS - Preferred Materials: The positive electrode active substance is a lithium manganese complex oxide having a spinel structure. The negative electrode active substance is a lithium titanium complex oxide and/or a lithium iron complex sulfide. The positive electrode electroconductive agent comprises a carbonaceous substance having a plane distance of the (002) plane (d002) of 0.344-0.352 microns and an average particle diameter of 0.1-10 microns. The positive electrode active substance comprises a compound of formula LiMO2.M=Ni, Mn, Co, or Al.It may be LiCoO2, LiNi1/3Mn1/3Co1/3O2, LiNi0.75CO0.20Al0.05O2, or LiNi0.5Mn0.5O2. The lithium manganese complex oxide comprises a complex oxide of formula Li1-xMn1.5-yNi0.5-zMy+zO4.M=Mg, Al, Ti, Fe, Co, Ni, Cu, Zn, Ga, Nb, Sn, Zr, or Ta;x=0-1;y+z=0-0.15.It is preferably LiMn1.5Ni0.5O4. The positive electrode active substance comprises LixCoO2, LixMn2O4, LixMnO2, LixNiO2, LiNi1-yCOyO2, LiMnyCo1-yO2, LixFePO4, LixFe1-yMnyPO4, or LixCoPO4. The lithium titanium complex oxide comprises a complex oxide of formula Li4+xTi5O12.x=0-3.The lithium iron complex sulfide comprises a complex sulfide of formula LixFeSy.x=0-4; andy=0.9-2.1.    TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Components: The negative electrode comprises a negative electrode collector (4a) and a negative electrode layer (4b) formed on at least one of surfaces of the negative electrode collector. The negative electrode layer has a thickness of 10-60 microns. The negative electrode layer comprises the negative electrode active substance, a negative electrode electroconductive agent and a binder. The positive electrode further comprises a positive electrode electroconductive agent and a binder. The outer housing comprises a laminated film having a thickness of less than or equal to0.2 mm. The laminated film may be a multilayer film containing a metallic layer and a resin layer coating the metallic layer.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Compounds: The electrolyte may comprise lithium tetrafluoroborate (LiBF4) and/or lithium hexafluorophosphate (LiPF6).    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Compounds: The nonaqueous electrolyte comprises an electrolyte including an imide lithium salt, preferably lithium perfluoromethylsulfonylimide (Li(CF3SO2)2N), lithium perfluoroethylmethylsulfonylimide (Li(CF3SO2)(C2F5SO2)N) or lithium perfluoroethylsulfonylimide (Li(C2F5SO2)2N), wherein the electrolyte is dissolved in the nonaqueous solvent. Preferred Composition: The electrolyte comprises 2-50 mole% imide lithium salt. The nonaqueous solvent comprises 85-90 vol.% diethyl carbonate.