Lithium ion secondary battery, current collector constituting the negative electrode of the secondary battery, and electrolytic copper foil constituting the negative electrode current collector

摘要

Excellent coatability of active material slurry, high battery capacity, little deterioration of battery capacity even after repeated charge / discharge cycles, and the same shape on both sides where active material coating layer does not peel from copper foil as negative electrode current collector To provide an electrolytic copper foil. To provide a lithium ion secondary battery using the electrolytic copper foil as a current collector, a negative electrode in which an active material is deposited on the current collector, and incorporating the negative electrode. An electrolytic copper foil constituting a negative electrode current collector of a lithium ion secondary battery, wherein both sides of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposited surface is an electrolytic copper foil having a crystalline structure of granular crystals. is there. Further, in the current collector made of the electrolytic copper foil constituting the negative electrode of the lithium ion secondary battery, both surfaces of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposition surface is composed of a granular crystal structure. .