Abstract: In a charge/discharge method for a positive-electrode active material in a lithium secondary battery, the lithium secondary battery includes a positive electrode containing a positive-electrode active material capable of occluding and releasing lithium ions, a negative electrode containing a negative-electrode active material capable of occluding and releasing lithium ions, a separator located between the positive electrode and the negative electrode, and an electrolyte having a lithium ion conductivity; and the positive-electrode active material contains a nickel-type lithium-containing complex oxide. The positive electrode, which has been charged, is discharged until having a first potential VDp1 which is no less than 2.7 V and no more than 3.4 V on a lithium metal basis, and then the discharge is finished. Owing to this, the charge/discharge cycle life can be improved while the capacity of the lithium secondary battery is secured.

Abstract: Having a current collector having a concave portion and a convex portion at least on one side, and a columnar body formed on the convex portion of the current collector, the columnar body contains an active material for inserting and extracting lithium ions bonding at least with oxygen, and the oxygen content ratio of the active material of the columnar body becomes smaller as going away from the interface of the current collector.

Abstract: Disclosed is a negative electrode for a lithium ion secondary battery, the negative electrode including a negative electrode current collector with protrusions formed on a surface thereon, and columnar bodies being carried on the protrusions and comprising an alloy active material capable of absorbing and releasing lithium ions. The columnar bodies each have a multilayer structure in which a plurality of unit layers comprising the alloy active material are stacked sequentially on the surface of the protrusion, and the average layer thickness of the unit layer in a region within 20% of the thickness of the columnar body extending from the surface of the protrusion is smaller than that in a region within 80% of the thickness of the columnar body extending from the top of the columnar body.

Abstract: A negative electrode for a lithium ion secondary battery includes a negative electrode core member and a negative electrode mixture layer adhering to the negative electrode core member. The negative electrode mixture layer includes active material particles, a cellulose ether compound, and rubber particles. The cellulose ether compound has a degree of etherification of 0.25 or more and 0.7 or less and an average degree of polymerization of 20 or more and 1200 or less. The negative electrode mixture layer contains remaining particles including a water-insoluble portion of the cellulose ether compound and having a mean particle size of 1 ?m or more and 75 ?m or less. The bonding strength between the active material particles is 98 N/cm2 or more.

Abstract: An electrode for a lithium secondary battery including a sheet-like current collector and an active material layer carried on the current collector. The active material layer is capable of absorbing and desorbing lithium, and the active material layer includes a plurality of columnar particles having at least one bend. An angle ?1 formed by a growth direction of the columnar particles from a bottom to a first bend of the columnar particles, and a direction normal to the current collector is preferably 10° or more and less than 90°. When ?n+1 is an angle formed by a growth direction of the columnar particles from an n-th bend counted from a bottom of the columnar particles to an (n+1)-th bend, and the direction normal to the current collector, and n is an integer of 1 or more, ?n+1 is preferably 0° or more and less than 90°.

Abstract: In order to enhance charge and discharge efficiency and to improve cycle characteristics by increasing a facing area between a positive electrode active material and a negative electrode active material, in a negative electrode for lithium secondary battery having a current collector and an active material layer carried on the current collector, the active material layer includes a plurality of columnar particles. The columnar particles include an element of silicon, and are tilted toward the normal direction of the current collector. Angle ? formed between the columnar particles and the normal direction of the current collector is preferably 10°??<90°.

Abstract: According to a deterioration detecting method for rechargeable lithium batteries, battery voltages of a rechargeable lithium battery before and after the completion of charging or discharging are measured. An evaluation value is calculated based on the measured battery voltages. This evaluation value is compared with a reference value of the rechargeable lithium battery stored in advance. A deterioration level of the rechargeable lithium battery is estimated based on this comparison result. In addition, further deterioration can be suppressed by controlling charging and discharging of the rechargeable lithium battery based on the estimated deterioration level.

Abstract: A nonaqueous electrolyte secondary battery includes: a positive electrode 1; and a negative electrode 2. When the battery is charged in an environment of 25° C. at a constant current of 0.7 C until a voltage value reaches 4.2 V, and is charged at a constant voltage of 4.2 V until a current value decreases to 0.05 C, capacity of the electrode per unit area is 3.5 mAh/cm2 to 7.0 mAh/cm2, both inclusive, and charge capacity of the negative electrode active material is 300 mAh/g to 330 mAh/g, both inclusive. Internal resistance of the battery is controlled in such a manner that the voltage value reaches 4.2 V when the battery is charged to 50% to 85%, both inclusive, of standard capacity in the environment of 25° C. at the constant current of 0.7 C.

Abstract: To provide a lithium secondary battery which has high capacity while maintaining excellent cycle characteristic. The lithium secondary battery cathode of the present invention includes a cathode collector formed of a conductive substance, and a cathode active material layer formed of a sintered lithium composite oxide sheet. The cathode active material layer is bonded to the cathode collector by the mediation of a conductive bonding layer. A characteristic feature of the present invention resides in that the cathode active material layer has a thickness of 30 ?m or more, a voidage of 3 to 30%, and an open pore ratio of 70% or higher.

Abstract: To provide a lithium secondary battery which has high capacity while maintaining excellent cycle characteristic. The lithium secondary battery cathode of the present invention includes a cathode collector formed of a conductive substance, and a cathode active material layer formed of a sintered lithium composite oxide sheet. The cathode active material layer is bonded to the cathode collector by the mediation of a conductive bonding layer. A characteristic feature of the present invention resides in that the cathode active material layer has a thickness of 30 ?m or more, a mean pore size of 0.1 to 5 ?m, and a voidage of 3% or more and less than 15%.

Abstract: In order to enhance charge and discharge efficiency and to improve cycle characteristics by increasing a facing area between a positive electrode active material and a negative electrode active material, in a negative electrode for lithium secondary battery having a current collector and an active material layer carried on the current collector, the active material layer includes a plurality of columnar particles. The columnar particles include an element of silicon, and are tilted toward the normal direction of the current collector. Angle ? formed between the columnar particles and the normal direction of the current collector is preferably 10°??<90°.

Abstract: A non-aqueous electrolyte secondary battery comprising at least a negative electrode having a current collector provided thereon with convex portions and columnar bodies formed on the convex portions, each of the columnar bodies comprising n stages (where n?2) of overlaid columnar body portions alternately tilted to different orientations along a longitudinal direction of the current collector, a positive electrode having a positive electrode current collector provided on both surfaces thereof with a positive electrode mixture layer containing a positive electrode active material capable of inserting and extracting lithium ions reversibly, and a separator interposed between the positive electrode and the negative electrode in a confronting manner, wherein tip portions of the columnar body portions at the uppermost stage of the columnar bodies on the negative electrode are tilted toward a trailing end of winding direction.

Abstract: A negative electrode for a non-aqueous electrolyte secondary battery includes a negative electrode core member and a negative electrode mixture layer adhering to the negative electrode core member. The negative electrode mixture layer includes graphite particles, a water-soluble polymer coating the surfaces of the graphite particles, and a binder bonding the graphite particles coated with the water-soluble polymer. The negative electrode mixture layer has a specific surface area of 2.2 to 3 m2/g, and the bonding strength between the graphite particles coated with the water-soluble polymer is 14 kgf/cm2 or more. A non-aqueous electrolyte secondary battery including this electrode has good coulombic efficiency, since decomposition of the components of the non-aqueous electrolyte due to reaction between the graphite particles and the non-aqueous electrolyte is suppressed.

Abstract: A battery pack includes at least a lithium ion secondary battery, a voltage sensor, and a control unit. The control unit controls discharge of the battery by a relatively high end-of-discharge voltage when the use frequency of the battery is relatively low during discharge of the battery. On the other hand, the control unit controls discharge of the battery by a relatively low end-of-discharge voltage when the use frequency of the battery is relatively high. Consequently, it is possible to prevent the utilizable capacity from decreasing more than a practical decrease in the capacity due to increase in the use frequency.

Abstract: In a charging method for a non-aqueous electrolyte secondary battery which includes a positive electrode including a lithium-containing composite oxide as an active material, a negative electrode including an alloy-formable negative electrode active material, and a non-aqueous electrolyte, a voltage of the secondary battery is detected. When the detected value is smaller than a predetermined voltage x, charging is performed at a comparatively small current value B. When the detected value is equal to or greater than the predetermined voltage x and smaller than a predetermined voltage z, charging is performed at a comparatively great current value A. When the detected value is equal to or greater than the predetermined voltage z and smaller than a predetermined voltage y, charging is performed at a comparatively small current value C. When the detected value is greater than the predetermined voltage y, constant-voltage charging is performed or charging is terminated. Here, x<z<y.

Abstract: A non-aqueous electrolyte secondary battery comprising a negative electrode having a current collector provided with convex portions and concave portions on both surfaces, a first columnar body formed in a tilting orientation on the convex portion on one of the surfaces of the current collector, and a second columnar body formed in a tilting orientation on the convex portion on the other surface, a positive electrode having a positive electrode current collector provided with a positive electrode mixture layer containing a positive electrode active material capable of reversibly inserting and extracting lithium ions on both surfaces, and a separator interposed between the positive electrode and the negative electrode in a confronting manner, wherein the first columnar body and the second columnar body on the negative electrode are tilted to an orthogonal direction of a winding direction of the current collector.

Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode (4), a negative electrode (5), a porous insulating layer (6), and a nonaqueous electrolyte. In the positive electrode (4), a positive electrode mixture layer (4B) is provided on at least one surface of a positive electrode current collector (4A). A tensile extension percentage of the positive electrode (4) is 3.0% or more. The positive electrode current collector (4A) contains iron. A porosity of the positive electrode mixture layer (4B) is 17% or less.

Abstract: A negative electrode for a non-aqueous electrolyte secondary battery reversibly inserting and extracting lithium ions, and including current collector having concave portion and convex portion on at least one surface thereof; and columnar body formed on convex portion of current collector and including columnar body portions laminated in n stages (n?2) in which a content ratio of an element sequentially changes in the longitudinal direction of the current collector. The content ratio of an element is different between in an odd stage and in an even stage of columnar body portions.

Abstract: A non-aqueous electrolyte secondary battery including: a positive electrode; a negative electrode, and a non-aqueous electrolyte. The negative electrode includes a negative electrode active material that includes at least Si. The non-aqueous electrolyte includes lithium hexafluorophosphate as a main supporting electrolyte and has an acid content of not less than 50 ppm and not more than 200 ppm. The negative electrode has a potential of not less than 0.6 V and not more than 1.5 V relative to a Li electrode at an end-of-discharge voltage of the battery. The battery is prevented from suffering degradation of storage characteristics caused by the dissolution reaction of Si from the negative electrode during charging and the precipitation reaction of the dissolved Si.

Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode (4), a negative electrode (5), and a porous insulating layer (6). The porous insulating layer (6) is provided between the positive electrode (4) and the negative electrode (5). A tensile extension percentage of the positive electrode (4) is 3% or more. In other words, a positive electrode current collector (4A) contains an aluminum particle whose average particle size is 1 ?m or more. A positive electrode mixture layer (4B) is provided on at least one surface of the positive electrode current collector (4A), and contains a positive electrode active material and an organic material whose melting point or softening point is higher than 200° C.