A lithium-ion secondary battery is provided where the production process line that fabricated it can be identified. The lithium-ion secondary battery includes a jelly roll, a positive electrode tab, a negative electrode tab, a positive electrode can, and a lid. The jelly roll is made by rolling the positive electrode and the negative electrode with an interposed separator, and is contained in the casing. The positive electrode tab has one end connected to the positive electrode of the jelly roll and the other end connected to the lid. The negative electrode tab has one end connected to the negative electrode of the jelly roll and the other end connected to a terminal provided on the lid. The other end of the negative electrode tab has a shape with a cut at a cut angle determined in accordance with the production process line that fabricated the lithium-ion secondary battery.