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 negative electrode 10 for a lithium ion battery of the present invention includes a negative electrode current collector 11, protrusions 13 formed so as to be spaced apart from each other on a surface of the negative electrode current collector 11, columns 12 supported on the protrusions 13 one by one, and a coating layer 15 coating a surface of each of the columns 12. The columns 12 include a negative electrode active material including either one of silicon and tin, and further include lithium absorbed thereinto. The coating layer 15 contains at least one of lithium carbonate and lithium fluoride and is formed by exposing the columns 12 to an atmosphere with a dew point temperature of ?60° C. or higher and 0° C. or lower.

Abstract: A battery pack 1 includes a battery 10, thickness detection means 11, cycle number detection means 12, and first determination means 13. The battery 10 is an alloy-type secondary battery having an electrode assembly 20 which includes a positive electrode, a negative electrode including an alloyable active material, and an insulating layer. The thickness detection means 11 detects the thickness of the electrode assembly 20 of the battery 10. The cycle number detection means 12 detects the number of charge and discharge cycles of the battery 10. The first determination means 13 determines the replacement time of the battery 10 according to the detection results by the thickness detection means 11 and the cycle number detection means 12. This configuration allows the battery pack including the alloy-type secondary battery to estimate the replacement time of the alloy-type secondary battery almost accurately, thereby enhancing the convenience of the battery pack.

Abstract: A negative electrode for a non-aqueous electrolyte secondary battery including: a current collector; and an active material layer including at least two alloy-based active materials selected from the group consisting of silicon, tin, a silicon oxide, and a tin oxide. The active material layer includes a first portion supported on a surface of the current collector, a second portion supported on a surface of the first portion, and a third portion supported on a surface of the second portion. The first portion includes the silicon oxide or the tin oxide, and the oxygen content in the silicon oxide or the tin oxide in the first portion decreases continuously or stepwise as approaching the second portion. The second portion includes silicon or tin. The third portion includes the silicon oxide or the tin oxide, and the oxygen content in the silicon oxide or the tin oxide in the third portion increases continuously or stepwise with distance from the second portion.

Abstract: The invention relates to a battery current collector including a metal foil for carrying at least a positive electrode active material or a negative electrode active material. At least one side of the metal foil has a compressed base plane and non-compressed protrusions arranged at a predetermined interval, and the non-compressed protrusions are formed at the same time as formation of the base plane. The surface roughness of the base plane is different from the surface roughness of the protrusions, and the surface roughness of the base plane is preferably an arithmetic mean roughness of 0.8 ?m or less.

Abstract: A current collector including a substrate, a plurality of projections, and a chipped portion is provided. The substrate is a metal sheet. The projections are formed on the surface of the substrate. The chipped portion is an aggregate of two or more, preferably 2 to 100 of minute projections. The minute projections are formed on the substrate surface, and are the protrusions having the height of below 35% of the average height of the projections. By forming an electrode active material layer on the face of the current collector where the projections are formed to make an electrode, the detachment of the electrode active material layer, and the spread of the detachment are significantly curbed. By using this electrode, a non-aqueous electrolyte secondary battery which have high battery capacity and energy density, excellent charge and discharge cycle characteristics, and which is capable of keeping a high-output stably for a long period of time can be obtained.