NEGATIVE ELECTRODE COLLECTOR COPPER FOIL FOR LITHIUM ION SECONDARY BATTERY, LITHIUM ION SECONDARY BATTERY AND REDUCTION ROLL

摘要

PROBLEM TO BE SOLVED: To obtain: a negative electrode collector copper foil for a lithium ion secondary battery, capable of improving adhesion between a negative electrode collector copper foil and a negative electrode active material; a lithium ion secondary battery; and a reduction roll used in rolling a negative electrode collector copper foil for a lithium ion secondary battery.SOLUTION: In a negative electrode active material layer, a plurality of projecting parts are arranged to be in parallel each other on at least one main surface thereof. The projecting parts are respectively arranged line-symmetrically with respect to an axis that passes the center of a negative electrode collector copper foil in a direction orthogonal to the rolling direction of the negative electrode collector copper foil and is parallel in the rolling direction.