| abstract |
A subject for the invention is to provide a lithium secondary battery which can be improved in high-output/high-input characteristics based on a reduction in the thickness of an active material layer, has a long life, and is highly safe. The invention relates to: a negative-electrode active material for lithium secondary battery, which is in a carbonaceous powder form and in which when a dispersion prepared by dispersing 100 g of the active-material powder in 200 g of water together with 2 g of carboxymethyl cellulose is examined by the grind gauge method for determining the degree of dispersion in accordance with JIS K5400, the particle diameter at which particles begin to appear is 50 μm or smaller; a negative electrode for lithium secondary battery which comprises a current collector having provided thereon an active material layer comprising an active material and an organic material having binding and thickening effects, wherein the active material layer has a thickness of 50 μm or smaller and an arithmetic mean roughness (Ra) as measured in accordance with JIS B0601 of 5 μm or smaller; and a lithium secondary battery employing the negative electrode. |