Abstract: The object of an exemplary embodiment of the invention is to provide a lithium ion secondary battery having an excellent charge and discharge cycle property. An exemplary embodiment of the invention is a lithium ion secondary battery, comprising a battery assembly in which a positive electrode and a negative electrode are stacked through a separator and a package in which the battery assembly and an electrolyte are placed; wherein the negative electrode comprises a negative electrode collector which is composed of a metal and a negative electrode active material layer which is formed on the negative electrode collector and which comprises a negative electrode active material and a binder; wherein the negative electrode collector and the negative electrode active material layer have a crack which is formed so as to be communicated with each of them; and wherein the crack reaches an outer peripheral edge from an inside of the negative electrode.

Abstract: An organic acid included in a nonaqueous electrolyte solution of a secondary battery is reduced. During preparation of a film-covered battery 1, the nonaqueous electrolyte solution is injected into an covering 5 of the film-covered battery 1 having an electrode including: the electrode active material, the binder, and the organic acid, the organic acid in the nonaqueous electrolyte solution is decomposed by electrical charging of a battery until a voltage level is equal to or above a decomposition voltage of the organic acid, and the gas that is produced by decomposition is degassed from the cut portion 6 of the covering 5.

Abstract: A mixed electrode for a nonaqueous electrolyte battery includes: a first active material; a second active material that reacts with water more easily than the first active material; an organic moisture capture agent; and an organic binder that binds the first active material and the second active material. The organic moisture capture agent is present in the organic binder and the first active material has a smaller specific surface area than the second active material. Thus, the storability of the mixed electrode is improved and when the mixed electrode is applied to the battery, the cycle characteristics of the battery are improved.

Abstract: A control system for a lithium secondary battery measures a voltage V of a negative electrode that uses silicon oxide as a negative electrode active material, with respect to a lithium reference electrode and a discharge capacity Q of the lithium secondary battery during discharge of the lithium secondary battery; generates a V?dQ/dV curve representing a relationship between dQ/dV, which is a proportion of an amount of change dQ in the discharge capacity Q to an amount of change dV in the voltage V, and the voltage V; calculates an intensity ratio of two peaks appearing on the V?dQ/dV curve for two voltage values in the voltage V; and senses a state of the negative electrode utilizing the intensity ratio.

Abstract: A mixed electrode for a nonaqueous electrolyte battery includes: a first active material; a second active material that reacts with water more easily than the first active material; an organic moisture capture agent; and an organic binder that binds the first active material and the second active material. The organic moisture capture agent is present in the organic binder and the first active material has a smaller specific surface area than the second active material. Thus, the storability of the mixed electrode is improved and when the mixed electrode is applied to the battery, the cycle characteristics of the battery are improved.

Abstract: Provided is a negative electrode active material for a lithium secondary cell, the material having the function of a binder for the active material, and being capable of stable reversible reactions with lithium. Also, provided are an extended-life lithium secondary cell having improved energy density and stable charge/discharge, and a method for producing the same. The negative electrode active material for a lithium secondary cell is polyimide represented by formula (1) (wherein R1 and R2 independently denote an alkyl, alkoxy, acyl, phenyl, or phenoxy group).

Abstract: Provided is a nonaqueous electrolytic solution secondary battery having a high energy density, and a positive electrode and a negative electrode used therefor. The nonaqueous electrolytic solution secondary battery includes a positive electrode and a negative electrode, wherein: the negative electrode contains a negative electrode active material having an initial charge/discharge efficiency of 75% or less when charged and discharged by employing metallic Li as a counter electrode; and the positive electrode contains a metal oxide (X) represented by AxMeOy (wherein A is Na and/or K, Me is Ni and/or Cu, x satisfies 1.9?x?2.1, and y satisfies 1.9?y?2.1).

Abstract: There is provided a negative electrode for a nonaqueous electrolyte secondary battery in which when a battery is formed, the energy density is high, and moreover, the decrease in charge and discharge capacity is small even if charge and discharge are repeated. By using silicon oxide particles having a particle diameter in a particular range as a starting raw material, and heating these particles in the range of 850° C. to 1050° C., Si microcrystals are deposited on the surfaces of the particles. Then, by performing doping of Li, a structure comprising a plurality of protrusions having height and cross-sectional area in a particular range is formed on the surfaces. The average value of the height of the above protrusions is 2% to 19% of the average particle diameter of the above lithium-containing silicon oxide particles.

Abstract: The object of an exemplary embodiment of the invention is to provide a negative electrode having excellent cycle property. An exemplary embodiment of the invention a method for doping and dedoping lithium for the first time after a negative electrode for a lithium secondary battery comprising silicon oxide as an active material is produced, comprising doping the lithium within the following current value range (A) and within the following doped amount range (B); current value range (A): a range of a current value in which a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve becomes maximum, wherein the V-dQ/dV curve represents a relationship between voltage V of the negative electrode with respect to a lithium reference electrode and dQ/dV that is a ratio of variation dQ of lithium dedoped amount Q in the negative electrode to variation dV of the voltage V, and doped amount range (B): a range of a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve.

Abstract: There is provided a control system for a lithium secondary battery that can quantitatively sense a deterioration state inherent in a lithium secondary battery using silicon oxide as a negative electrode active material, that is, the nonuniform reaction state of a negative electrode.

Abstract: A secondary battery according to the present exemplary embodiment is a secondary battery including a laminated electrode body provided with at least one pair of positive and negative electrodes and an outer enclosure that accommodates the laminated electrode body, wherein the outer enclosure includes one or more concave portions, inside a border corresponding to an outer edge of an electrode surface of an outermost layer of the laminated electrode body, on a surface facing the electrode surface, and wherein, when a band-shaped outer circumferential region having an area that is a half of an area inside the border is set inside the border, at least one of the concave portions is located inside the outer circumferential region.

Abstract: There is provided a control system for a lithium secondary battery that can quantitatively sense a deterioration state inherent in a lithium secondary battery using silicon oxide as a negative electrode active material, that is, the nonuniform reaction state of a negative electrode.

Abstract: An organic acid included in a nonaqueous electrolyte solution of a secondary battery is reduced. During preparation of a film-covered battery 1, the nonaqueous electrolyte solution is injected into an covering 5 of the film-covered battery 1 having an electrode including: the electrode active material, the binder, and the organic acid, the organic acid in the nonaqueous electrolyte solution is decomposed by electrical charging of a battery until a voltage level is equal to or above a decomposition voltage of the organic acid, and the gas that is produced by decomposition is degassed from the cut portion 6 of the covering 5.

Abstract: In a lithium ion secondary battery including a positive electrode, a separator, a negative electrode, and a package body, the negative electrode includes simple substance silicon as a negative electrode active material, and a negative electrode binder, and is doped with lithium, and the following formulas (1) and (2) are satisfied: 1.2?Ma/Mc?1.9??(1) 1.0<Ma/(Mc+MLi)<1.6??(2) wherein an amount of lithium inserted into the negative electrode until the negative electrode reaches a potential of 0.02 V with respect to metal lithium is Ma (a number of atoms), an amount of lithium released from the positive electrode until the positive electrode reaches a potential of 4.3 V with respect to metal lithium is Mc (a number of atoms), and an amount of lithium with which the negative electrode is doped is MLi (a number of atoms).

Abstract: The object of an exemplary embodiment of the invention is to provide a lithium ion secondary battery having an excellent charge and discharge cycle property. An exemplary embodiment of the invention is a lithium ion secondary battery, comprising a battery assembly in which a positive electrode and a negative electrode are stacked through a separator and a package in which the battery assembly and an electrolyte are placed; wherein the negative electrode comprises a negative electrode collector which is composed of a metal and a negative electrode active material layer which is formed on the negative electrode collector and which comprises a negative electrode active material and a binder; wherein the negative electrode collector and the negative electrode active material layer have a crack which is formed so as to be communicated with each of them; and wherein the crack reaches an outer peripheral edge from an inside of the negative electrode.

Abstract: The object of an exemplary embodiment of the invention is to provide a negative electrode having excellent cycle property. An exemplary embodiment of the invention a method for doping and dedoping lithium for the first time after a negative electrode for a lithium secondary battery comprising silicon oxide as an active material is produced, comprising doping the lithium within the following current value range (A) and within the following doped amount range (B); current value range (A): a range of a current value in which a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve becomes maximum, wherein the V-dQ/dV curve represents a relationship between voltage V of the negative electrode with respect to a lithium reference electrode and dQ/dV that is a ratio of variation dQ of lithium dedoped amount Q in the negative electrode to variation dV of the voltage V, and doped amount range (B): a range of a doped amount in which only one peak appears at 1 V or less on the V-dQ/dV curve.

Abstract: Provided is a lithium secondary cell in which elution of manganese from a manganese olivine compound into an electrolyte is suppressed, a high level of safety is obtained, the charge/discharge cycle efficiency and suppression of leakage of manganese during storage can be maintained over a long period, a long lifespan is obtained, a rapid decrease in cell voltage near the end of discharge is suppressed, and output characteristics are enhanced, when a manganese olivine compound having excellent stability during charge/discharge is used as the principal component in the positive electrode active material. The positive electrode contains a positive electrode active material containing an olivine compound represented by LiMm1-aXaPO4 (where X represents Mg and/or Fe, and a represents a value that satisfies 0?a?0.3) and a lithium nickel oxide represented by LiNi1-bZbO2 (where Z represents one or more selected from Co, Mn, Al, Mg, and V; and b represents a value that satisfies 0?b?0.

Abstract: Provided is a negative electrode active material for a lithium secondary cell, the material having the function of a binder for the active material, and being capable of stable reversible reactions with lithium. Also, provided are an extended-life lithium secondary cell having improved energy density and stable charge/discharge, and a method for producing the same. The negative electrode active material for a lithium secondary cell is polyimide represented by formula (1) (wherein R1 and R2 independently denote an alkyl, alkoxy, acyl, phenyl, or phenoxy group).

Abstract: In a nonaqueous electrolyte secondary battery using silicon and silicon oxide as a negative electrode active material, the charge and discharge cycle characteristics are improved. A nonaqueous electrolyte secondary battery in the exemplary embodiment comprises a sheet-shaped negative electrode comprising a negative electrode active material layer comprising a composite of silicon and silicon oxide formed on a negative electrode current collector, and a sheet-shaped positive electrode comprising a positive electrode active material layer formed on a positive electrode current collector, wherein the negative electrode is disposed opposed to the positive electrode via a separator, a peripheral edge portion of the negative electrode active material layer is disposed within a peripheral edge portion of the positive electrode active material layer, and a relationship of 1.00<c is satisfied when a charge capacity of the positive electrode is a, a charge capacity of the negative electrode is b, and b/a=c is set.

Abstract: Provided is a nonaqueous electrolytic solution secondary battery having a high energy density, and a positive electrode and a negative electrode used therefor. The nonaqueous electrolytic solution secondary battery includes a positive electrode and a negative electrode, wherein: the negative electrode contains a negative electrode active material having an initial charge/discharge efficiency of 75% or less when charged and discharged by employing metallic Li as a ocounter electrode; and the positive electrode contains a metal oxide (X) represented by AxMeOy (wherein A is Na and/or K, Me is Ni and/or Cu, x satisfies 1.9?x?2.1, and y satisfies 1.9?y?2.1).