HIGH STRENGTH NICKEL-PLATED HEAT-TREATED STEEL SHEET FOR BATTERY CASE AND MANUFACTURING METHOD THEREOF

The present disclosure relates to a high-strength nickel-plated heat-treated steel sheet for a battery case and a manufacturing method thereof. In one embodiment, the nickel-plated heat-treated steel sheet comprises a base steel sheet containing 0.002 to 0.05 wt % of carbon (C); a nickel layer formed on at least one surface of the base steel sheet; and a nickel-iron (Ni—Fe) diffusion layer formed between the base steel sheet and the nickel layer, wherein the nickel-plated heat-treated steel sheet is manufactured by subjecting a plated sheet, in which a nickel plating layer is formed on at least one surface of the base steel sheet, to an alloying heat treatment, and satisfies the condition of the following Equation 1. (In Equation 1, TSis the tensile strength (MPa) of the plated sheet, and TSis the tensile strength (MPa) of the nickel-plated heat-treated steel sheet.)