| abstract |
Provided is a negative electrode power collection body for lithium ion secondary cell with high strength and large discharge capacity, wherein the negative electrode power collection body used copper covered steel foil 10 for supporting negative electrode active material of lithium ion secondary cell, in which copper covered steel foil 10 has steel sheet 6 as core material with copper cover layer 7 having an average film thickness tCu of 0.02 to 5.0 μ m for each single layer provided upon both faces of steel sheet 6, and an average thickness t including copper cover layer 7 is 3 to 100 μ m and tCu / t is not more than 0.3. Steel sheet 6 can be, for example, ordinary steel, austenitic stainless steel or ferritic stainless steel. Copper cover layer 7 is, for example, copper electroplated layer (including the one rolled after plating). Upon the surface of copper cover layer 7, for example, carbon-based active material layer being highly densified by intensive roll press is provided, and a negative electrode power collection body is constituted by copper covered steel foil 10 and the carbon-based active material layer. |