Abstract: A control method includes determining whether an internal resistance of a secondary battery is higher than a first threshold resistance, performing first discharge of the secondary battery if it is determined that the internal resistance is higher than the first threshold resistance, and performing at least one of a charge operation of the secondary battery and a discharge operation of the secondary battery after the first discharge is performed.

Abstract: A negative electrode for an electrochemical device includes: a negative current collector; a first negative electrode active material layer supported on a first surface of the negative current collector; and a second negative electrode active material layer supported on a second surface of the negative current collector. And capacity C1 per unit mass of the first negative electrode active material layer is greater than capacity C2 per unit mass of the second negative electrode active material layer. As a result, it is possible to provide a negative electrode suited for an electrochemical device having high capacitance, the electrochemical device being manufactured by pre-doping the negative electrode with lithium ions.

Abstract: A negative electrode for an electrochemical device includes: a negative current collector; a first negative electrode active material layer supported on a first surface of the negative current collector; and a second negative electrode active material layer supported on a second surface of the negative current collector. And capacity C1 per unit mass of the first negative electrode active material layer is greater than capacity C2 per unit mass of the second negative electrode active material layer. As a result, it is possible to provide a negative electrode suited for an electrochemical device having high capacitance, the electrochemical device being manufactured by pre-doping the negative electrode with lithium ions.

Abstract: The present invention provides an electrolyte highly reliable in charge and discharge in a high voltage condition, and an electrochemical capacitor using the same. The electrolyte of the present invention includes a solvent, an electrolyte salt having an anion having a perfluoro alkyl group represented by a following composition formula, and an acid inducing substance having a fluorine atom for an anion, characterized in that the weight ratio of the acid inducing substance is in a range of 0.0001 to 2.0 wt %: MX+[Q(Rf)yFz]X? (wherein Q is a group 13 or group 15 element in the periodic table, Rf is a perfluoro alkyl group (CnF2n+1), n is a natural number, 1?y<6, 1?z<6, MX+ is a cation of Xth valence, and X is a natural number from 1 to 3).

Abstract: A lithium ion capacitor includes a positive electrode, a negative electrode, and a non-protonic organic solvent electrolytic solution of a lithium salt. A positive electrode active material is a material capable of reversibly doping a lithium ion and/or an anion. A negative electrode active material is a material capable of reversibly doping a lithium ion. The lithium ion is doped in advance to either one or both of the negative electrode and the positive electrode so that a positive electrode potential after the positive electrode and the negative electrode are short-circuited is 2.0 V (relative to Li/Li+) or less when capacitance per unit weight of the positive electrode is C+(F/g), weight of the positive electrode active material is W+(g), capacitance per unit weight of negative electrode is C?(F/g), and weight of the negative electrode active material is W?(g), a value of (C?×W?)/(C+×W+) is 5 or more.

Abstract: A lithium ion capacitor includes a positive electrode made of a material capable of reversibly carrying either one or both of a lithium ion and an anion, a negative electrode made of a material capable of reversibly carrying a lithium ion, and an electrolytic solution made of a non-protonic organic solvent electrolytic solution of a lithium salt. A negative electrode active material is non-graphitizable carbon having a ratio of number of hydrogen atoms to number of carbon atoms of zero or more and less than 0.05. The lithium ion is doped in advance to either one or both of the negative electrode and the positive electrode so that a negative electrode potential when a cell is discharged to a voltage one half a charging voltage of the cell is 0.15 V or less relative to a lithium ion potential.

Abstract: The present invention provides an electrolyte highly reliable in charge and discharge in a high voltage condition, and an electrochemical capacitor using the same. The electrolyte of the present invention includes a solvent, an electrolyte salt having an anion having a perfluoro alkyl group represented by a following composition formula, and an acid inducing substance having a fluorine atom for an anion, characterized in that the weight ratio of the acid inducing substance is in a range of 0.0001 to 2.0 wt %: MX+[Q(Rf)yFz]X? (wherein Q is a group 13 or group 15 element in the periodic table, Rf is a perfluoro alkyl group (CnF2n+1), n is a natural number, 1?y<6, 1?z<6, MX+ is a cation of Xth valence, and X is a natural number from 1 to 3).

Abstract: A lithium ion capacitor having a high capacity retention at the time of continuous charge at a high temperature and excellent durability. The lithium ion capacitor includes a positive electrode, a negative electrode and an aprotic organic solvent electrolyte solution of a lithium salt as an electrolytic solution. The positive electrode active material is a material capable of reversibly supporting lithium ions and/or anions, a negative electrode active material is a material capable of reversibly supporting lithium ions, the negative electrode and/or the positive electrode is doped with lithium ions so that the potential of the positive electrode is at most 2.0 V after the positive electrode and the negative electrode are short-circuited, and the electrolytic solution contains vinylene carbonate or its derivative.

Abstract: A lithium ion capacitor including a positive electrode, a negative electrode, and an aprotic organic solvent solution of a lithium salt as an electrolytic solution. The positive electrode active material is capable of reversibly supporting lithium ions and/or anions, the negative electrode active material is capable of reversibly supporting lithium ions and anions, and the potentials of the positive electrode and the negative electrode are at most 2.0 V after the positive electrode and the negative electrode are short-circuited. The positive electrode and the negative electrode are alternately laminated with a separator interposed therebetween to constitute an electrode unit, the cell is constituted by at least two such electrode units, lithium metal is disposed between the electrode units, and lithium ions are preliminarily supported by the negative electrode and/or the positive electrode by electrochemical contact of the lithium metal with the negative electrode and/or the positive electrode.

Abstract: A lithium ion capacitor includes a positive electrode made of a material capable of reversibly carrying either one or both of a lithium ion and an anion, a negative electrode made of a material capable of reversibly carrying a lithium ion, and an electrolytic solution made of a non-protonic organic solvent electrolytic solution of a lithium salt. A negative electrode active material is non-graphitizable carbon having a ratio of number of hydrogen atoms to number of carbon atoms of zero or more and less than 0.05. The lithium ion is doped in advance to either one or both of the negative electrode and the positive electrode so that a negative electrode potential when a cell is discharged to a voltage one half a charging voltage of the cell is 0.15 V or less relative to a lithium ion potential.

Abstract: It is to provide a lithium ion capacitor having a high energy density, a high output density, a large capacity and high safety. A lithium ion capacitor comprising a positive electrode, a negative electrode and an aprotic organic solvent solution of a lithium salt as an electrolytic solution, wherein a positive electrode active material is a material capable of reversibly supporting lithium ions and anions, a negative electrode active material is a material capable of reversibly supporting lithium ions, and the potentials of the positive electrode and the negative electrode are at most 2.

Abstract: It is to provide a lithium ion capacitor having a high capacity retention at the time of continuous charge at a high temperature and excellent in durability. A lithium ion capacitor comprising a positive electrode, a negative electrode and an aprotic organic solvent electrolyte solution of a lithium salt as an electrolytic solution, characterized in that a positive electrode active material is a material capable of reversibly supporting lithium ions and/or anions, a negative electrode active material is a material capable of reversibly supporting lithium ions, the negative electrode and/or the positive electrode is doped with lithium ions so that the potential of the positive electrode is at most 2.0 V after the positive electrode and the negative electrode are short-circuited, and the electrolytic solution contains vinylene carbonate or its derivative.

Abstract: A lithium ion capacitor includes a positive electrode, a negative electrode, and a non-protonic organic solvent electrolytic solution of a lithium salt. A positive electrode active material is a material capable of reversibly doping a lithium ion and/or an anion. A negative electrode active material is a material capable of reversibly doping a lithium ion. The lithium ion is doped in advance to either one or both of the negative electrode and the positive electrode so that a positive electrode potential after the positive electrode and the negative electrode are short-circuited is 2.0 V (relative to Li/Li+) or less when capacitance per unit weight of the positive electrode is C+(F/g), weight of the positive electrode active material is W+(g), capacitance per unit weight of negative electrode is C?(F/g), and weight of the negative electrode active material is W?(g), a value of (C?×W?)/(C+×W+) is 5 or more.

Abstract: A lithium ion capacitor including a positive electrode, a negative electrode, and an aprotic organic solvent solution of a lithium salt as an electrolytic solution. The positive electrode active material is capable of reversibly supporting lithium ions and/or anions, the negative electrode active material is capable of reversibly supporting lithium ions and anions, and the potentials of the positive electrode and the negative electrode are at most 2.0 V after the positive electrode and the negative electrode are short-circuited. The positive electrode and the negative electrode are alternately laminated with a separator interposed therebetween to constitute an electrode unit, the cell is constituted by at least two such electrode units, lithium metal is disposed between the electrode units, and lithium ions are preliminarily supported by the negative electrode and/or the positive electrode by electrochemical contact of the lithium metal with the negative electrode and/or the positive electrode.

Abstract: A lithium ion capacitor includes a positive electrode including a positive electrode active material capable of reversibly doping either one or both of a lithium ion and an anion, a negative electrode including a negative electrode active material capable of reversibly doping a lithium ion, and a non-protonic organic solvent electrolytic solution of a lithium salt as an electrolytic solution. The lithium ion is doped to either one or both of the negative electrode and positive electrode so that the positive electrode potential after the positive electrode and negative electrode are short-circuited is 2.0 V or less. A surface of the negative electrode is covered with a polymer.

Abstract: It is to provide a lithium ion capacitor having a high energy density, a high output density, a large capacity and high safety. A lithium ion capacitor comprising a positive electrode, a negative electrode and an aprotic organic solvent solution of a lithium salt as an electrolytic solution, wherein a positive electrode active material is a material capable of reversibly supporting lithium ions and anions, a negative electrode active material is a material capable of reversibly supporting lithium ions, and the potentials of the positive electrode and the negative electrode are at most 2.