LITHIUM ION SECONDARY CELL, CURRENT COLLECTOR CONSTITUTING NEGATIVE ELECTRODE OF SECONDARY CELL, AND ELECTROLYTIC COPPER FOIL CONSTITUTING NEGATIVE-ELECTRODE CURRENT COLLECTOR

摘要

Provided is an electrolytic copper foil having excellent coatability by an active material slurry, high cell capacity, minimal cell capacity loss even after repeated charge-discharge cycles, and nearly the same morphology on both sides thereof, such that an active material coating film does not peel away from the copper foil as a negative-electrode current collector. Also provided is a lithium ion secondary cell wherein the electrolytic copper foil is a current collector, an active material is deposited on the current collector to form a negative electrode, and the negative electrode is incorporated into the lithium ion secondary cell. The electrolytic copper foil constitutes a negative-electrode current collector of the lithium ion secondary cell, both sides of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposited sides have a granular crystalline structure. In the current collector comprising the electrolytic copper foil constituting the negative electrode of the lithium ion secondary cell, both sides of the electrolytic copper foil are formed by electrolytic deposition, and the electrolytic deposited sides are configured from a granular crystalline structure.