Abstract: A positive electrode for secondary cell comprising a current collector which is comprised of aluminum or an aluminum alloy and a positive electrode active material layer, wherein the positive electrode active material layer contains a positive electrode active material, a water-based binder, an organic phosphonic acid compound, and a polyvalent metal compound is provided. According to the present invention, a positive electrode for secondary cell which is high in initial capacity and excellent in rate characteristics and high temperature cycle characteristics can be provided.

Abstract: Disclosed is a negative electrode active material for a lithium ion secondary battery, which is capable of further improving the charge/discharge cycle characteristics. Also disclosed is a lithium ion secondary battery which uses the negative electrode active material for a lithium ion secondary battery. The negative electrode active material for a lithium ion secondary battery is composed of composite particles each of which has a core/shell structure configured of a core part that is formed from a polymer and a shell part that is formed of a metal layer. The metal layer of the shell part is formed by metal plating. Preferably, the metal layer comprises at least a metal layer (a1) that is formed by electroless plating and a metal layer (a2) that is formed by electrolytic plating, in this order from the core part side.

Abstract: Disclosed is an electrode for a lithium-ion secondary battery which includes a porous membrane layer that is inhibited from decreasing in flexibility. The electrode for lithium-ion secondary battery comprises a current collector and, formed thereon in the following order, an electrode active-material layer comprising an electrode active material, a thickener, and a binder and a porous membrane layer containing an inorganic filler, wherein the binder is one which, when used to form a composite film comprising the binder and the thickener, forms a spherical island phase in a cross section of the composite film, the island phase having an average diameter of 0.5 ?m or larger. The binder preferably is an unsaturated carboxylic acid ester polymer having a content of alkyl acrylate monomer units of 85 mass % or higher.