Abstract: A negative electrode for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes a base portion near the current collector and pillar-shaped portions formed on the base portion. A negative electrode for a nonaqueous electrolyte secondary battery according to another aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes pillar-shaped portions and the particle diameter of the negative electrode active material particle is 20% or less of the maximum diameter of the pillar-shaped portions.

Abstract: There are provided a negative electrode for a nonaqueous electrolyte secondary battery having excellent initial efficiency and good moldability of pillar portions included in a negative electrode mixture layer, and a nonaqueous electrolyte secondary battery. A negative electrode (20) for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode current collector (21) and a negative electrode mixture layer (22) formed on the negative electrode current collector (21) and containing a binder and a negative electrode active material particle that forms an alloy with lithium. The negative electrode mixture layer (22) includes a base portion (22a) near the negative electrode current collector (21) and pillar portions (22b) formed on the base portion (21a). The binder contains a polyimide resin. The polyimide resin has an average molecular weight of 60000 or more.

Abstract: Provided is a negative electrode active material, containing at least silicon, for nonaqueous electrolyte secondary batteries. Since the negative electrode active material contains silicon, the negative electrode active material has high capacity and excellent cycle characteristics. A negative electrode active material for nonaqueous electrolyte secondary batteries contains at least silicon. At least, one portion of the surface of each of primary particles containing silicon is covered with an inert phase made of a silicon compound with a silicon oxidation number higher than that of the silicon, a metal-silicon alloy, or metal. The primary particles containing silicon may form secondary particles. The silicon compound with a silicon oxidation number higher than that of silicon is preferably Li2Si2O5, Li2SiO3, or Li4SiO4. Furthermore, the metal-silicon alloy is preferably FeSi and the metal is preferably Ti. Furthermore, the crystallite size of silicon is 500 ? or less.

Abstract: There are provided a negative electrode for a nonaqueous electrolyte secondary battery having excellent initial efficiency and good moldability of pillar portions included in a negative electrode mixture layer, and a nonaqueous electrolyte secondary battery. A negative electrode (20) for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode current collector (21) and a negative electrode mixture layer (22) formed on the negative electrode current collector (21) and containing a binder and a negative electrode active material particle that forms an alloy with lithium. The negative electrode mixture layer (22) includes a base portion (22a) near the negative electrode current collector (21) and pillar portions (22b) formed on the base portion (21a). The binder contains a polyimide resin. The polyimide resin has an average molecular weight of 60000 or more.

Abstract: A nonaqueous electrolyte secondary battery which has a good capacity retention ratio (cycle characteristics) and in which the expansion and shrinkage during charging and discharging are small compared with the case where a negative electrode made of only a negative electrode active material that forms an alloy with lithium is used. A negative electrode for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode mixture layer formed on a current collector and containing a binder and a negative electrode active material particle that forms an alloy with lithium. The negative electrode mixture layer includes pillar portions, and a value of S1/S2 is 0.46 or more and 0.58 or less, where S1 represents a total area of the pillar portions in plan view and S2 represents a total area of one surface of the negative electrode current collector in plan view.

Abstract: A negative electrode for a nonaqueous electrolyte secondary battery according to one aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes a base portion near the current collector and pillar-shaped portions formed on the base portion. A negative electrode for a nonaqueous electrolyte secondary battery according to another aspect of the present invention includes a negative electrode mixture layer that contains a binder and a negative electrode active material particle that forms an alloy with lithium and is formed on a current collector. The negative electrode mixture layer includes pillar-shaped portions and the particle diameter of the negative electrode active material particle is 20% or less of the maximum diameter of the pillar-shaped portions.