Patent ID: 8216718

Claim:
An anode for lithium-ion secondary battery comprising: a current collector; and an active material-containing layer formed on the current collector, wherein the active material-containing layer is comprised of an outermost layer disposed on the farthest side from the current collector, and a lower layer composed of at least one layer disposed between the outermost layer and the current collector, the outermost layer has a structure in which active material particles are bound by a binder, and the lower layer has a structure in which active material particles are bound by a binder, wherein a degree of flexion of the outermost layer is larger than a degree of flexion of the lower layer, wherein the degree of flexion of the lower layer is not less than 1.8 nor more than 3.0, and wherein an average particle size of the active material particles contained in the outermost layer is smaller than an average particle size of the active material particles contained in the lower layer, the degree of flexion of the outermost layer and the degree of flexion of the lower layer being defined as ratio: L′/L where L is a thickness of a layer, which is any of the outermost layer and the lower layer, obtained by drawing a straight line A perpendicular to the layer, and L′ is a numerical value, in the same unit as L, of a sum of maximum diameters of active material particles crossing the straight line A in a lateral direction perpendicular to the straight line A.