| abstract |
A lithium ion battery current collector which is used in a lithium ion battery in contact with an electrode active material at one principal surface, characterized in that the current collector is provided with a surface layer on the principal surface in contact with the electrode active material, and an uneven structure is provided on a surface in which the surface layer is in contact with the electrode active material, the uneven structure is any of a plurality of recesses composed of closed figures as seen from above, a network structure, or a pattern of recesses and protrusions, which is provided in an outermost layer of the surface layer, and a depth of the recess is 10 to 45 μm, a length of a shortest portion of lengths passing through a centroid of the recess is 30 to 105 μm, and a proportion of an area of the recess as seen from above is 19% to 61% with respect to an area of a surface of the current collector provided with the recess as seen from above. |