Abstract: A nonaqueous electrolyte secondary battery having an enhanced capacity and a long charge/discharge cycle life is disclosed. The nonaqueous electrolyte secondary battery comprises a positive electrode housed in a case and containing a chalcogen compound as an active material, a negative electrode arranged in the case such that a separator is sandwiched between the positive and negative electrodes and containing a carbonaceous material as an active material that absorbs and discharges lithium ions and a nonaqueous electrolyte contained in the case and prepared by dissolving 0.5 mol/l to 1.5 mol/l of electrolytic salt selected from the group consisting of LiPF.sub.6, LiBF.sub.4, LiAsF.sub.6 and LiCF.sub.3 SO.sub.3 in a solvent mixture comprising at least one first nonaqueous solvent selected from the group consisting of noncyclic carbonate, cyclic carbonate, .gamma.

Abstract: A nonaqueous electrolyte secondary battery comprising a positive electrode housed in a case a negative electrode arranged in the case so that a separator is sandwiched between the positive and negative electrodes consisting of lithium or lithium-containing material, and a nonaqueous electrolyte contained in the case and prepared by dissolving an electrolytic salt consisting of lithium phosphate hexafluoride (LiPF.sub.6) or lithium borofluoride (LiBF.sub.4) in a solvent mixture consisting of ethylene carbonate, 2-methyltetrahydrofuran, and at least one ester-based nonaqueous solvent selected from the group consisting of butylene carbonate, dimethyl carbonate, .gamma.-butyrolactone, and sulfolane.

Abstract: There is disclosed a secondary battery having a negative electrode composed of an active substance and a carrier carrying the active substance, which comprises(1) the active substance is lithium or an alkali metal mainly composed of lithium,(2) the carrier is a mixture composed of(a) a carbonaceous material having(i) an atomic ratio of hydrogen/carbon of less than 0.15 and(ii) a spacing of (002) planes (d.sub.002) as determined by X-ray wide angle diffraction of 3.37 .ANG. or more and a crystallite size in the direction of c axis of 150 .ANG. or less, and(b) a metal capable of forming an alloy with the active substance and/or an alloy with the active substance.