SURFACE-TREATED STEEL SHEET FOR USE AS BATTERY CASING, BATTERY CASING, AND BATTERY

摘要

This invention provides a surface-treated steel sheet (100) for use as a battery casing, said surface-treated steel sheet being obtained by plating a steel sheet (10) with an iron-nickel alloy and then performing a heat treatment. Said surface-treated steel sheet (100) is characterized in that the topmost layer thereof is an iron-nickel alloy layer (20) and the average grain size in the top surface of said iron-nickel alloy layer (20) is between 1 and 8 µm, inclusive. This invention makes it possible to provide the following: a surface-treated steel sheet that, when used as a battery casing, inhibits elution of iron inside the battery, thereby increasing the service life of the battery, and also improves battery characteristics such as discharge characteristics; and a battery casing and battery obtained using said surface-treated steel sheet.