Abstract: Provided is a lithium secondary battery in which negative-electrode active material particles containing silicon and/or a silicon alloy are used and which prevents the occurrence of breakage of a binder itself and peel-off of the binder at the interfaces with the negative-electrode active material and the negative-electrode current collector and has a high energy density and an excellent cycle characteristic. The lithium secondary battery includes: a negative electrode in which a negative-electrode active material layer including negative-electrode active material particles containing silicon and/or a silicon alloy and a binder is formed on a surface of electrically conductive metal foil serving as a negative-electrode current collector; a positive electrode; and a nonaqueous electrolyte, wherein the binder contains a polyimide resin including a crosslinked structure formed by imidization of a hexavalent or higher-valent carboxylic acid or an anhydride thereof with a diamine.

Abstract: Provided is a nonaqueous electrolyte secondary battery which, even in the case of using a low-viscosity solvent having a narrow potential window, can increase the electrochemical stability of the nonaqueous electrolyte solution and suppress side reactions of the nonaqueous electrolyte solution during charge and discharge to reduce the degradation of the battery characteristics and has an excellent storage characteristic in high-temperature environments and a nonaqueous electrolyte solution for the nonaqueous electrolyte secondary battery.

Abstract: A lithium secondary battery which is unlikely to be deformed during charging and discharging. A lithium secondary battery includes a spiral-shaped electrode assembly and a cylindrical battery container. The battery container receives the electrode assembly. The electrode assembly includes a negative electrode, a positive electrode, and a separator. The negative electrode includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is disposed on the negative electrode collector. The negative electrode active material layer contains a negative electrode active material forming an alloy with lithium. The positive electrode faces the negative electrode. The separator is disposed between the negative electrode and the positive electrode. When A is a proof stress of the negative electrode collector multiplied by the thickness thereof and a capacity to be charged per unit area of the negative electrode is represented by B, A?0.

Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode having a positive-electrode active material, a negative electrode having a negative-electrode active material, and a nonaqueous electrolytic solution having a nonaqueous solvent dissolving a solute. The negative-electrode active material includes powdered silicon and/or a silicon alloy, the nonaqueous electrolytic solution includes additives composed of at least one fluorinated lithium phosphate selected from the group consisting of lithium monofluorophosphate, lithium difluorophosphate, and lithium trifluorophosphate and a diisocyanate compound, and the nonaqueous solvent includes a chain carbonate compound.

Abstract: The present invention is made to improve charge-discharge cycle performances under high temperature environment in a non-aqueous electrolyte secondary battery using a negative electrode containing a negative electrode active material of particulate silicon and/or silicon alloy and a binding agent.

Abstract: This invention provides a negative electrode material for a rechargeable battery with a nonaqueous electrolyte, characterized in that the negative electrode material contains polycrystalline silicon particles as an active material, the particle diameter of crystallites of the polycrystalline silicon is not less than 20 nm and not more than 100 nm in terms of a crystallite size determined by the Scherrer method from the full width at half maximum of a diffraction line attributable to Si (111) around 2?=28.4° in an x-ray diffraction pattern analysis, and the true specific gravity of the silicon particles is 2.300 to 2.320.

Abstract: A rechargeable lithium battery including a negative electrode made by depositing a noncrystalline thin film composed entirely or mainly of silicon on a current collector, a positive electrode and a nonaqueous electrolyte, characterized in that said nonaqueous electrolyte contains carbon dioxide dissolved therein.

Abstract: A method of charging and discharging a lithium secondary battery in which a negative electrode comprises an active material including silicon provided on a current collector which is a metal which does not form an alloy with lithium. The method is characterized in that the lithium secondary battery is charged and discharged within a range of state of charge (SOC) at which no peak corresponding to a compound of lithium and silicon is observed in an X-ray diffraction pattern during charging using CuK?-radiation as the X-ray source.

Abstract: Provided is a lithium secondary battery in which negative-electrode active material particles containing silicon and/or a silicon alloy are used and which prevents the occurrence of breakage of a binder itself and peel-off of the binder at the interfaces with the negative-electrode active material and the negative-electrode current collector and has a high energy density and an excellent cycle characteristic. The lithium secondary battery includes: a negative electrode in which a negative-electrode active material layer including negative-electrode active material particles containing silicon and/or a silicon alloy and a binder is formed on a surface of electrically conductive metal foil serving as a negative-electrode current collector; a positive electrode; and a nonaqueous electrolyte, wherein the binder contains a polyimide resin including a crosslinked structure formed by imidization of a hexavalent or higher-valent carboxylic acid or an anhydride thereof with a diamine.

Abstract: Provided is a nonaqueous electrolyte secondary battery which, even in the case of using a low-viscosity solvent having a narrow potential window, can increase the electrochemical stability of the nonaqueous electrolyte solution and suppress side reactions of the nonaqueous electrolyte solution during charge and discharge to reduce the degradation of the battery characteristics and has an excellent storage characteristic in high-temperature environments and a nonaqueous electrolyte solution for the nonaqueous electrolyte secondary battery.

Abstract: A lithium secondary battery contains a negative electrode binder containing a polyimide resin having a structure represented by the following chemical formula (1), and the polyimide resin having a molecular weight distribution such that the weight ratio of a polyimide resin having a molecular weight of less than 100,000 and a polyimide resin having a molecular weight from 100,000 to less than 200,000 is from 50:50 to 90:10: where n is an integer equal to or greater than 1, and R is a functional group represented by the following chemical formula (2) or (3):

Abstract: A lithium secondary battery of the present invention comprises a positive electrode formed by disposing a positive-electrode mixture layer containing a positive-electrode active material and a positive-electrode binder, on a surface of a positive-electrode current collector; a negative electrode formed by sintering a negative-electrode mixture layer containing a negative-electrode binder and a negative-electrode active material containing silicon and/or a silicon alloy, disposed on a surface of a negative-electrode current collector; a separator disposed between the positive electrode and the negative electrode; and a nonaqueous electrolyte; wherein an electrode unit obtained by setting the positive electrode and the negative electrode opposed to each other through the separator and rolling them in spirally rolled state is placed in a cylindrical battery container and wherein a curvature radius of the negative-electrode mixture layer opposed to the positive-electrode mixture layer through the separator in the

Abstract: A nonaqueous electrolyte secondary battery in which the decomposition of an electrolyte solution is reduced exhibits high coulombic efficiency and excellent charge and discharge cycle performance, and has high energy density. This nonaqueous electrolyte secondary battery includes a negative electrode that is formed by depositing a thin film of active material on a collector by a CVD method, sputtering, evaporation, thermal spraying, or plating, wherein the thin film of the active material can lithiate and delithiate and is divided into columns by cracks formed in the thickness direction, and the bottom of each column is adhered to the collector; a positive electrode that can lithiate and delithiate; and a nonaqueous electrolyte solution containing a lithium salt in a nonaqueous solvent. The electrolyte solution contains a compound expressed by a general formula (I).

Abstract: A non-aqueous electrolyte secondary battery has a positive electrode (1), a negative electrode (2), a separator (3) interposed between the positive electrode and the negative electrode, and a non-aqueous electrolyte solution in which a solute is dissolved in a non-aqueous solvent. The negative electrode contains a negative electrode active material capable of alloying with lithium and the non-aqueous solvent of the non-aqueous electrolyte solution contains one ore more fluorinated cyclic carbonates and a carboxylic ester. In addition, the non-aqueous electrolyte solution contains a nitrile compound having a chain saturated hydrocarbon group having two or more carbon atoms.

Abstract: A lithium ion secondary battery 1 includes a spirally wound electrode assembly 20 and a cylindrical battery container 10. The spirally wound electrode assembly 20 includes a negative electrode 21, a positive electrode 22 and a separator 23. The negative electrode 21 includes negative-electrode active material layers 21b and 21c containing a negative-electrode active material capable of forming an alloy with lithium. The lithium ion secondary battery 1 includes an urging part 20a. The urging part 20a is disposed in the center of and in contact with the spirally wound electrode assembly 20. The urging part 20a is contractible in diameter. The urging part 20a is configured to urge the spirally wound electrode assembly 20 radially outward at least when contracting in diameter.

Abstract: A rechargeable lithium battery including a negative electrode made by sintering, on a surface of a conductive metal foil as a current collector, a layer of a mixture of active material particles containing silicon and/or a silicon alloy and a binder, a positive electrode and a nonaqueous electrolyte, characterized in that the nonaqueous electrolyte contains carbon dioxide dissolved therein.

Abstract: Provided is a binder capable of realizing a lithium secondary battery that includes a negative electrode including a negative-electrode active material layer containing at least one of silicon and a silicon alloy as a negative-electrode active material and also containing a binder and has an excellent charge-discharge cycle characteristic. The binder for the lithium secondary battery contains a polyimide resin that is formed by imidizing either a tetracarboxylic acid or a tetracarboxylic anhydride and a diamine, the polyimide resin having a hydrolyzable silyl group.

Abstract: A lithium secondary battery has a positive electrode, a separator, and a negative electrode having a negative electrode current collector and a negative electrode mixture layer formed on a surface of the negative electrode current collector. The negative electrode mixture layer contains a negative electrode active material including a metal element capable of alloying with lithium. The negative electrode current collector includes a substrate made of a Cu—Fe—P alloy foil, and a surface layer provided on both surfaces of the substrate and made of pure copper. The surface layer has a Vickers hardness of 120 and less than that of the substrate. The negative electrode current collector has a proof stress of 308 MPa.

Abstract: A lithium secondary battery has a wound electrode assembly (5). The wound electrode assembly (5) has a negative electrode (2) having a negative electrode active material layer containing a negative electrode active material capable of alloying with lithium and having a filling density of 2.0 g/cc or less, a positive electrode (1) having a positive electrode active material layer containing a positive electrode active material made of a transition metal composite oxide, a separator (3) disposed between the positive and negative electrodes and having a penetration resistance of 500 g or greater, and a cylindrical hollow space (14) at a winding axis and in the vicinity thereof, wherein the positive electrode (1), the negative electrode (2), and the separator (3) are spirally wound. A columnar center pin (15) having a diameter of from 75% to 95% of the diameter of the hollow space is disposed in the hollow space.

Abstract: A nonaqueous electrolyte secondary battery includes a positive electrode having a positive-electrode active material, a negative electrode having a negative-electrode active material, and a nonaqueous electrolytic solution having a nonaqueous solvent dissolving a solute. The negative-electrode active material includes powdered silicon and/or a silicon alloy, the nonaqueous electrolytic solution includes additives composed of at least one fluorinated lithium phosphate selected from the group consisting of lithium monofluorophosphate, lithium difluorophosphate, and lithium trifluorophosphate and a diisocyanate compound, and the nonaqueous solvent includes a chain carbonate compound.