Abstract: In a charging method for a lithium ion battery, constant current charging of the lithium ion battery is performed. The constant current charging includes at least three consecutive charging stages. The at least three consecutive charging stages include consecutive first, second, and third charging stages. The second charging stage has a set current value which is set lower than set current values of the first and third charging stages.

Abstract: In a charging method for a lithium ion battery, constant current charging of the lithium ion battery is performed. The constant current charging includes at least three consecutive charging stages. The at least three consecutive charging stages include consecutive first, second, and third charging stages. The second charging stage has a set current value which is set lower than set current values of the first and third charging stages.

Abstract: The method for producing a non-aqueous electrolyte secondary battery of the invention includes: (a) a step of preparing an electrode mixture slurry, (b) an ionization step of oxidizing and ionizing a metal impurity present in the electrode mixture slurry, and (c) a step of producing an electrode by using the electrode mixture slurry after the ionization step. In the invention, when the electrode mixture is in the form of a slurry, the metal impurity contained in the electrode mixture is ionized to minimize the amount of the impurity. Therefore, the invention can provide a highly reliable non-aqueous electrolyte secondary battery while minimizing a decrease in production yield by the metal impurity.

Abstract: A method for charging a non-aqueous electrolyte secondary battery including the step of repeating pulse charging and charging pause, in which a pulse charging time is arbitrarily set between a lower limit value and an upper limit value, the lower limit value being an inverse time Tx of a frequency Fx of the high frequency side at which an imaginary part of an alternating current impedance of the non-aqueous electrolyte secondary battery is a first local maximum value, or of a frequency adjacent to Fx, and the upper limit value being an inverse time Ty of a frequency Fy at the low frequency side at which an imaginary part of the alternating current impedance of the non-aqueous electrolyte secondary battery is a second local maximum value, or of a frequency adjacent to Fy.

Abstract: An object of the present invention is to provide a method for measuring information relating to the impedance characteristics of a powder with high accuracy. To achieve such an object, the method for measuring powder properties according to the present invention includes a step in which the impedance characteristics of a powder are obtained by an alternating current impedance method, using a function setting a pressure applied to the powder or a density of the powder as a variable. From the obtained impedance characteristics, information relating to at least one of the components can be extracted, the components being a first component that is dependent on the variable, and a second component that is not dependent on the variable.

Abstract: A lithium ion secondary battery with improved safety against both internal short-circuiting and overcharge is provided. This lithium ion secondary battery includes a positive electrode comprising a composite lithium oxide, a negative electrode, and a non-aqueous electrolyte. At least one of the positive electrode and the negative electrode has a porous film, comprising an inorganic oxide filler and a binder, on the surface facing the other electrode, and the electrode surface having the porous film partially has a protruded part. This protruded part may be a protruded part formed on the porous film itself or a protruded part formed on an electrode mixture layer. Further, a separator can also be incorporated therein. Instead of the above-mentioned porous film, the separator can be provided with a porous film.

Abstract: A method for evaluating an electrode material for a non-aqueous electrolyte secondary battery including the steps of: (A) vibrating an electrode material for a non-aqueous electrolyte secondary battery at a prescribed frequency successively in two or more levels of magnetic fields that have different magnetic flux densities; (B) detecting induced magnetizations that are synchronous with the vibrations generated in the electrode material; and (C) determining saturation magnetization of the electrode material from the induced magnetizations.

Abstract: Disclosed is a non-aqueous electrolyte secondary battery having an electrode group in which a positive electrode and a negative electrode are spirally wound with a separator interposed therebetween. The positive electrode contains a positive electrode active material and a binder. The positive electrode active material contains a mixture of two different particulate substances having different average particle sizes. The two different particulate substances are lithium composite metal oxides containing nickel as an essential element. The binder includes fluorocarbon resin and rubber particles. The fluorocarbon resin contains at least a vinylidene fluoride unit. The amount of the rubber particles per 100 parts by weight of the fluorocarbon resin is 1 to 25 parts by weight.

Abstract: A non-aqueous electrolyte secondary battery comprises a negative electrode including a negative electrode active material, a positive electrode including a positive electrode active material, and a non-aqueous electrolyte; the positive electrode active material is LiNi1-y-zMnyCozO2, wherein y and z satisfy 0<y?0.5, 0?z?0.5, and 0<y+z?0.75; and an upper limit voltage for charging the non-aqueous electrolyte secondary battery is 4.25 to 4.70 V. It is possible to obtain a non-aqueous electrolyte secondary with high capacity, high reliability, and long life by properly setting the composition of a composite oxide of lithium which is a positive electrode active material and the charging conditions of the battery using this composite oxide of lithium as a positive electrode active material as described above.

Abstract: The method for producing a non-aqueous electrolyte secondary battery of the invention includes: (a) a step of preparing an electrode mixture slurry, (b) an ionization step of oxidizing and ionizing a metal impurity present in the electrode mixture slurry, and (c) a step of producing an electrode by using the electrode mixture slurry after the ionization step. In the invention, when the electrode mixture is in the form of a slurry, the metal impurity contained in the electrode mixture is ionized to minimize the amount of the impurity. Therefore, the invention can provide a highly reliable non-aqueous electrolyte secondary battery while minimizing a decrease in production yield by the metal impurity.

Abstract: An object of the present invention is to provide a method for measuring information relating to the impedance characteristics of a powder with high accuracy. To achieve such an object, the method for measuring powder properties according to the present invention includes a step in which the impedance characteristics of a powder are obtained by an alternating current impedance method, using a function setting a pressure applied to the powder or a density of the powder as a variable. From the obtained impedance characteristics, information relating to at least one of the components can be extracted, the components being a first component that is dependent on the variable, and a second component that is not dependent on the variable.

Abstract: A method for charging a non-aqueous electrolyte secondary battery including the step of repeating pulse charging and charging pause, in which a pulse charging time is arbitrarily set between a lower limit value and an upper limit value, the lower limit value being an inverse time Tx of a frequency Fx of the high frequency side at which an imaginary part of an alternating current impedance of the non-aqueous electrolyte secondary battery is a first local maximum value, or of a frequency adjacent to Fx, and the upper limit value being an inverse time Ty of a frequency Fy at the low frequency side at which an imaginary part of the alternating current impedance of the non-aqueous electrolyte secondary battery is a second local maximum value, or of a frequency adjacent to Fy.

Abstract: A lithium ion secondary battery with improved safety against both internal short-circuiting and overcharge is provided. This lithium ion secondary battery includes a positive electrode comprising a composite lithium oxide, a negative electrode, and a non-aqueous electrolyte. At least one of the positive electrode and the negative electrode has a porous film, comprising an inorganic oxide filler and a binder, on the surface facing the other electrode, and the electrode surface having the porous film partially has a protruded part. This protruded part may be a protruded part formed on the porous film itself or a protruded part formed on an electrode mixture layer. Further, a separator can also be incorporated therein. Instead of the above-mentioned porous film, the separator can be provided with a porous film.

Abstract: Disclosed is a non-aqueous electrolyte secondary battery having an electrode group in which a positive electrode and a negative electrode are spirally wound with a separator interposed therebetween. The positive electrode contains a positive electrode active material and a binder. The positive electrode active material contains a mixture of two different particulate substances having different average particle sizes. The two different particulate substances are lithium composite metal oxides containing nickel as an essential element. The binder includes fluorocarbon resin and rubber particles. The fluorocarbon resin contains at least a vinylidene fluoride unit. The amount of the rubber particles per 100 parts by weight of the fluorocarbon resin is 1 to 25 parts by weight.

Abstract: A process of producing a positive electrode for lithium secondary batteries, including: at least, a coating preparing step of preparing a coating for a positive electrode material that includes an active material, which is a Li-containing mixed oxide, a conductive additive, a binder and a solvent; a coating step of coating the coating for a positive electrode material onto a current collector; a drying step of removing the solvent from the coating coated on the current collector; and a rolling step, wherein in the above described coating preparing step and coating step, the ratio of the total volume of the active material and the conductive additive to the volume of the solvent in the coating is kept in the range expressed by the following equation: 0.05?(volume of active material 1c+volume of conductive additive 1d)/volume of solvent?1.00.

Abstract: A non-aqueous electrolyte secondary battery comprises a negative electrode including a negative electrode active material, a positive electrode including a positive electrode active material, and a non-aqueous electrolyte; the positive electrode active material is LiNi1-y-zMnyCozO2, wherein y and z satisfy 0<y≦0.5, 0≦z≦0.5, and 0<y+z≦0.75; and an upper limit voltage for charging the non-aqueous electrolyte secondary battery is 4.25 to 4.70 V.