Patent ID: 8795846

Claim:
A Ni-plated steel sheet for a battery can having excellent press formability, wherein an Fe—Ni diffusion layer and a softened Ni layer formed on the Fe—Ni diffusion layer are formed on a surface of a steel sheet corresponding to an outer surface of the battery can, a semi-bright Ni plating layer is formed on the softened Ni layer, a Ni coating weight of the Fe—Ni diffusion layer and the softened Ni layer formed on the Fe—Ni diffusion layer is set smaller than a Ni coating weight of the semi-bright Ni plating layer, average roughness Ra of the semi-bright Ni plating layer measured by a traceable roughness gauge is 1.0 μm or more and 2.0 μm or less, and a maximum height Ry of the semi-bright Ni plating layer measured by the traceable roughness gauge is 5 μm or more and 20 μm or less, and surface roughness Ra′ of a surface of the semi-bright Ni plating layer in an area of 2.5 μm×2.5 μm which is obtained by an atomic force microscope falls within a range from 5 to 22 nm.