TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The cell or battery further comprises a positive electrode (cathode) made of metallic lithium or a second lithium-containing alloy, different to or the same as the first lithium-containing alloy.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The electrolyte solution comprises solvent(s) from tetrahydrofurane, 2-methyltetrahydrofurane, dimethylcarbonate, diethylcarbonate, ethylmethylcarbonate, methylpropylcarbonate, methylpropylpropionate, ethylpropylpropionate, methylacetate, ethylacetate, propylacetate, dimetoxyethane, 1,3-dioxalane, diglyme (2-methoxyethyl ether), tetraglyme, ethylenecarbonate, propylencarbonate, gamma -butyrolactone, or sulfolane. The electrolyte solution comprises salt(s) from lithium hexafluorophosphate (LiPF6), lithium hexafluoroarsenate (LiAsF6), lithium perchlorate (LiClO4), lithium sulfonylimid trifluoromethane (LiN(CF3SO2)2) or lithium trifluorosulfonate (CF3SO3Li) or other lithium salts or salts of another alkali metal or their mixture. The concentration of lithium salt(s) is 0.1-90% of a concentration of a saturated solution of the used salt (salts) in an aprotic solvent (solvents mixture).    TECHNOLOGY FOCUS - POLYMERS - Preferred Component: The electrolyte additives are lithium polysulfides having the formula Li2Sn. The lithium polysulfide concentration is 0.01M to 90% of the concentration of the saturated solution of the used salt (salts) in the aprotic solvent (solvents mixture).n=2-20, preferably 2-12 or 12-20. EXAMPLE - Sublimated sulfur (2 g, 99.5%) and lithium sulfide (0.57 g, 98%) were ground together in a high speed mill for 15-20 minutes in an atmosphere of dry argon (moisture content of 20-25 ppm). The ground mixture of lithium sulfide and sulfur was placed into a flask. An electrolyte (1M solution of lithium trifluoromethanesulfonate in sulfolane (99.8%)) (50 ml) was added to the flask. The content of the flask was mixed for 24 hours by using a magnetic stirrer at room temperature. Thus, a 0.25M solution of lithium polysulfide (Li2S6) in 1M solution of lithium trifluoromethanesulfonate in sulfolane was made.