TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Composition: The negative electrode material in battery cell comprises natural or artificial graphite which is pure or admixed with one or more of non-graphitic carbon, lithium terephthalate, lithium vanadium oxide (Li1+xVO2, where x is 0-1), lithium titanium oxide (Li4Ti5O12), lithium iron nitride (Li3+yFeN2, where y is -1 to 1), lithium titanium nitride (Li5+xTiN3), or three-phase mixture (2(1-z)LiH+(1-z)Mg+zMgH2, where z is 0-1). The positive electrode material in battery cell comprises layered oxide (LixM1O2, where M1 is cobalt, nickel or manganese) or spinel (LixMn2O4), in which a fraction of less than 15 wt.% transition elements are replaced by aluminum, magnesium or lithium, lithium nickel manganese oxide compound (LixNi0.5Mn1.5O4), lithium phosphate (LixM2PO4, where M2 is iron or manganese), in which a fraction of less than 10 wt.% transition elements are replaced by magnesium, sodium, or yttrium, fluorophosphates (Li1+xFePO4F or LixFePO3F2), and/or fluorosulfate (LixFeSO4F).    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Composition: The supporting portion contains pure iron having less than 2 wt.% impurities, and less than 0.1 wt.% carbon, and is foil-shaped having thickness of 50 mu m or less.    TECHNOLOGY FOCUS - METALLURGY - Preferred Composition: The supporting portion comprises a thin layer of copper or copper alloy arranged in contact with the electrode material. The supporting portion comprises an iron or iron alloy foil laminated with aluminum or aluminum alloy foil.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The electrolyte (11) in battery cell comprises a salt dissolved in a solvent, liquid, gel, or polymer. The salt comprises lithium hexafluorophosphate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, lithium trifluoromethaneborate, lithium pentafluoroethyltrifluoroborate, lithium cyanide compounds (Li(C(CN)3)), Li(CF3COC(CN)2), Li(CF3SO2C(CN)2), 2-trifluoromethyl-4,5-dicyanoimidazole, 2-trifluoroethyl-4,5-dicyanoimidazole, lithium sulfide compound (Li(RfSO2NSO2Rf), where Rf is fluoride, trifluoromethyl, pentafluoroethyl, C4F9, or C6F13). The electrolyte comprises a solvent containing one or more organic carbonates chosen from alicyclic or cyclic carbonates, such as ethylene and propylene carbonate, amides and urea containing dimethyl formamide, N-methylpyrrolidinone, N-ethyl-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, l,3-dimethyl-3,4,5,6-tetrahydro-2(lH)-pyrimidinone, dimethyl and diethyl-cyanamide, dimethyl sulfoxide, dimethyl sulfone, ( gamma )-butyrolactone, and a gelling agent chosen from polyvinylidene fluoride, its copolymers with hexafluoropropene, poly(alkyl)acrylate, poly(alkyl)methacrylate, or polyacrylonitrile, poly(ethylene oxide) as solvating polymers, polymers having more than 60% of ethylene oxide repeating units. An additive contained in electrolyte is chosen from vinylene carbonate, vinyl-ethylene carbonate, fluoro-ethylene carbonate, fluoromethyl-ethlylene carbonate, and bis(trifluoroethyl)-carbonate.