Abstract: A lithium-ion secondary cell includes a winding electrode assembly. The exposed area of the positive-electrode metal current collector body is formed at one end in a winding axis direction of the winding electrode assembly, and the exposed area of the negative-electrode metal current collector body is formed at another end in the winding axis direction of the winding electrode assembly; and the negative-electrode metal current collector body is a copper foil rolled to a thickness between 6 ?m and 15 ?m in which one or more of additive elements of Zr, Ag, Au, Pt, Cr, Cd, Sn, Sb, and Bi are added to Cu having a purity of equal to or greater than 99.9%, and the negative-electrode active material mix layer has a cavity volume ratio of between 30% and 60%.