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. TS2−TS1≥20(In Equation 1, TS1 is the tensile strength (MPa) of the plated sheet, and TS2 is the tensile strength (MPa) of the nickel-plated heat-treated steel sheet.)