Abstract: The invention provides a lithium secondary battery which is excellent in long-term cycle property and in battery characteristics, such as electric capacity and storage property, and a nonaqueous electrolytic solution usable for such a lithium secondary battery. The present invention relates to a lithium secondary battery including a positive electrode, a negative electrode, and a nonaqueous electrolytic solution containing an electrolyte salt dissolved in a nonaqueous solvent, characterized in that the positive electrode is made of a material including a lithium compound oxide, in that the negative electrode is made of a material including graphite, and in that the nonaqueous electrolytic solution contains dialkyl oxalate and further contains vinylene carbonate and/or 1,3-propanesultone, and a nonaqueous electrolytic solution for use in such a battery.

Abstract: 1. A non-aqueous electrolytic solution comprising an electrolytic salt in a non-aqueous solvent, which further contains a pentafluorophenoxy compound having the formula (I): in which R represents a substituting group such as an alkylcarbonyl group, an alkoxycarbonyl group, an aryloxy-carbonyl group, and an alkanesulfonyl group, under the condition that at least one hydrogen atom contained in the substituting group can be substituted with a halogen atom or an aryl group.

Abstract: A non-aqueous electrolytic solution composed of two or more organic compounds dissolved in a solvent composed of a cyclic carbonate and a chain carbonate, in an amount of 0.01 to 8 weight % for each compound, in which both of the two organic compounds have a reduction potential higher than those of the cyclic and chain carbonates, and in which one of the organic compounds has a reduction potential equal to that of another organic compound or has a reduction potential lower or higher than that of another organic compound by a potential of less than 0.4 V is favorably employable for a non-aqueous secondary battery.

Abstract: A nonaqueous electrolytic solution for lithium secondary batteries. When the nonaqueous solvent comprises a combination of an ester of a tertiary carboxylic acid and a cyclic carbonate such as propylene carbonate or ethylene carbonate, a lithium salt having a fluorine atom is preferably used as the electrolyte salt. In this case, the ester of a tertiary carboxylic acid is preferably used in a relatively small amount, especially in an amount of about 0.5 to 35 wt. % based on the nonaqueous solvent.

Abstract: A discharge capacity retention of a non-aqueous secondary battery is enhanced by incorporating into its non-aqueous electrolytic solution a small amount of a substituted diphenyldisulfide derivative in which each of the diphenyl groups has a substituent such as alkoxy, alkenyloxy, alkynyloxy, cycloalkyloxy, aryloxy, acyloxy, alkanesulfonyloxy, arylsulfonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, halogen, CF3, CCl3, or CBr3. Preferably, a small amount of methyl 2-propylcarbonate, 2-propynyl methanesulfonate, 1,3-propanesultone, divinylsulfone, 1,4-butanediol dimethanesulfonate or cyclohexylbenzene is further incorporated.

Abstract: A method of increasing the discharge capacity retention of a non-aqueous lithium ion secondary battery having a positive electrode active material, a combination of a lithium element and a complex metal oxide, a negative electrode, and a non-aqueous electrolytic solution comprising an electrolyte dissolved in a non-aqueous solvent which is a combination of a cyclic carbonate and a linear carbonate by incorporating a disulfide derivative having the formula: R1—S—S—R2 wherein each of R1 and R2 independently represents a phenyl group, a benzyl group, a tolyl group, a pyridyl group, a pyrimidyl group, an alkyl group having 1 to 12 carbon atom, or a cycloalkyl group having 3 to 6 carbon atoms, in which each group has no substituent groups or has one or more alkyl groups into the non-aqueous electrolytic solution.

Abstract: An electrolysis solution for electrolytic capacitors including an aqueous organic solvent consisting of water and a water-compatible organic solvent and 1,6-decane-dicarboxylic acid or salt thereof dissolved therein. The solution further contains one or more additives selected from dinitriles, pivalic acid and salts thereof, diesters, alkylated lactones, cyanoalkanoic esters, monocarbboxylic acids each having a C3-7 alkyl chain and substituted with two C1-4 alkyl groups at the &bgr;-position to the carboxyl group and salts thereof, monocarboxylic acids each having C3-7 alkyl chain and substituted with one ethyl group at the &agr;-position to the carboxyl group and salts thereof, and monocarboxylic acids derived from cyclic saturated compounds each having five or six ring-constituting carbon atoms and salts thereof.

Abstract: A non-aqueous electrolyte comprising (i) a non-aqueous solvent, especially mainly composed of a cyclic carbonate and a cyclic ester and optionally a linear carbonate, and (ii) an electrolyte salt, especially LiBF4, dissolved therein and (iii) a vinyl sulfone derivative having the formula (I): 1

Abstract: In order to manufacture a lithium secondary battery having excellent performances in safety under overcharge condition, cycle property, electric capacity, and storage endurance, 0.1 wt. % to 10 wt. % of a tert-alkylbenzene compound is favorably incorporated into a non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, preferably in combination with 0.1 wt. % to 1.5 wt. % of a biphenyl compound.

Abstract: A non-aqueous electrolytic solution containing a ketone compound having the formula (I): 1

Abstract: An electrolysis solution for electrolytic capacitors comprising an aqueous organic solvent consisting of water and a water-compatible organic solvent and 1,6-decanedicarboxylic acid or a salt thereof dissolved therein, which solution further contains one or more additives selected from the group consisting of dinitriles, pivalic acid and salts thereof, diesters, alkylated lactones, cyanoalkanoic esters, monocarboxylic acids each having a C3-7 alkyl chain and being substituted with two C1-4 alkyl groups at the &bgr;-position to the carboxyl group and salts thereof, monocarboxylic acids each having a C3-7 alkyl chain and being substituted with one ethyl group at the &agr;-position to the carboxyl group and salts thereof, and monocarboxylic acids derived from cyclic saturated compounds each having five or six ring-constituting carbon atoms and salts thereof.

Abstract: A nonaqueous electrolytic solution for lithium secondary batteries. When nonaqueous solvent comprises a combination of an ester of a tertiary carboxylic acid and a cyclic carbonate such as propylene carbonate or ethylene carbonate, a lithium salt having a fluorine atom is preferably used as the electrolyte salt. In this case, the ester of a tertiary carboxylic acid is preferably used in a relatively small amount, especially in an amount of about 0.5 to 35 wt. % based on the nonaqueous solvent.

Abstract: A non-aqueous electrolyte comprising a non-aqueous solvent and a lithium salt dissolved therein, and a cyclic carbonate, linear carbonate, and vinylene carbonate having a chlorine content of 100 ppm or less, and a lithium secondary battery using the same.

Abstract: A non-aqueous electrolytic solution comprising a non-aqueous solvent and an electrolyte, which further contains a combination of a nitrile compound and an S═O group-containing compound (or a dinitrile compound) in an amount of 0.001 to 10 wt. % imparts improved cycle performance and storage property to a lithium battery, particularly a lithium secondary battery.

Abstract: A non-aqueous electrolyte comprising (i) a non-aqueous solvent, especially mainly composed of a cyclic carbonate and a cyclic ester and optionally a linear carbonate, and (ii) an electrolyte salt, especially LiBF4, dissolved therein and (iii) a vinyl sulfone derivative having the formula (I): 1

Abstract: A non-aqueous electrolyte containing a non-aqueous solvent, an electrolyte salt dissolved therein and a tert-butylbenzene derivative having the formula (I): wherein R1, R2, R3, R4 and R5 independently represent a hydrogen atom or C1 to C12 hydrocarbon group and a lithium secondary battery using the same.

Abstract: An electrolyte for a lithium secondary battery comprising (i) a non-aqueous solvent, especially consists essentially of a high dielectric solvent and a low viscosity solvent, and (ii) an electrolyte salt, dissolved therein and (iii) an alkyne derivative or an alkyne carbonate derivative and also a lithium secondary battery using the same are disclosed.

Abstract: A discharge capacity retention of a non-aqueous secondary battery is enhanced by incorporating into its non-aqueous electrolytic solution a small amount of a substituted diphenyldisulfide derivative in which each of the diphenyl groups has a substituent such as alkoxy, alkenyloxy, alkynyloxy, cycloalkyloxy, aryloxy, acyloxy, alkanesulfonyloxy, arylsulfonyloxy, alkoxycarbonyloxy, aryloxycarbonyloxy, halogen, CF3, CCl3, or CBr3. Preferably, a small amount of methyl 2-propylcarbonate, 2-propynyl methanesulfonate, 1,3-propanesultone, divinylsulfone, 1,4-butanediol dimethanesulfonate or cyclohexylbenzene is further incorporated.

Abstract: A non-aqueous electrolyte comprising (i) a non-aqueous solvent and (ii) an electrolyte salt dissolved therein and (iii) a disulfonate ester derivative having the formula (I): wherein R indicates a C1 to C6 alkyl group and X indicates a straight-chain alkylene group having a C2-C6 principal chain or a branched alkylene group having a C2-C6 principal chain with at least one side-chain composed of a. C1-C4 alkyl group, and also a lithium secondary battery using the same are disclosed.

Abstract: A lithium secondary battery electrolyte comprising a non-aqueous solvent and a lithium salt dissolved therein, said electrolyte containing at least one compound having the formula (I) or (II): wherein, R1 and R2 independently indicate, a C1 to C12 alkyl group, a C3 to C6 cycloalkyl group, or an aryl group, x indicates an oxygen atom or a sulfur atom, and n indicates an integer of 1 or 2; R3—S—M  (II) wherein, R3 indicates a C1 to C15 alkyl group or a C3 to C12 cycloalkyl group which may be substituted with at least one C1 to C4 alkyl group, a C7 to C15 benzyl group which may be substituted with at least one C1 to C4 alkyl group, or a C6 to C15 aryl group, which may be substituted with at least one C1 to C4 alkyl group, M indicates an alkali metal, and R3 may be substituted with at least one halogen atom; and a lithium secondary battery using the same.