▎ 摘　　要

NOVELTY - A negative-electrode active material comprises short-length cup-stack type carbon nanotube of length 3 mu m or less obtained by laminating two or more of graphene sheet of cup type structure and graphene sheet of cup type structure in which the bottom is opened. USE - Negative-electrode active material is used for negative electrodes (claimed) of lithium ion secondary batteries used in hybrid electric vehicles and electric vehicles. ADVANTAGE - The negative-electrode active material has high capacity. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for negative electrode consisting of a negative mix layer containing the active material which can occlude/release lithium ion, formed on both surfaces of collector. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the cup-type nanocarbon.