Abstract: A lithium ion secondary battery includes a positive electrode having a positive electrode active material layer on a current collector, a negative electrode having a negative electrode active material layer on a current collector, and a separator disposed between the positive electrode and the negative electrode and impregnated with a non-aqueous electrolyte solution. The positive electrode active material layer contains a positive electrode active material and a binder, the negative electrode active material layer contains a negative electrode active material and a binder, the binder of the negative electrode active material layer contains a copolymer of vinyl alcohol and an alkali metal neutralized product of ethylenically unsaturated carboxylic acid, and the separator includes a polymeric base material containing an inorganic compound or includes a polymer having a melting point or glass transition temperature of 140° C. or higher.

Abstract: Provided are a lithium ion secondary battery in which heat generation is suppressed when the battery is internally short-circuited by an external impact, such as nail penetration or collapse, or short-circuited by foreign matter contamination or the like; and an electrical appliance using the battery. More specifically, the following lithium ion secondary battery and electrical appliance comprising the lithium ion secondary battery are provided.

Abstract: There is provided an electrode binder that has sufficient binding force and can reduce the resistance of a nonaqueous electrolyte secondary battery. The binder for a nonaqueous electrolyte secondary battery electrode comprises a copolymer of a vinyl alcohol and an alkali metal-neutralized product of ethylenically unsaturated carboxylic acid; and at least one of poly(meth)acrylic acid and an alkali metal-neutralized product of poly(meth)acrylic acid.