ELECTROLYTIC COPPER FOIL AND MANUFACTURING METHOD THEREFOR, CURRENT COLLECTOR FOR LITHIUM SECONDARY BATTERY COMPRISING ELECTROLYTIC COPPER FOIL, AND LITHIUM SECONDARY BATTERY

摘要

An electrolytic copper foil according to one embodiment of the present invention is used as a current collector for a lithium secondary battery, and the electrolytic copper foil has a fracture characteristic coefficient (f) ranging from 5.0 to 18.0 after the electrolytic copper foil is annealed at 190°C for an hour, wherein the fracture characteristic coefficient (f) is defined as f={(C-B)/A}×1000 where A denotes stress of the electrolytic copper foil at a moment when the fracture of the electrolytic copper foil is initiated, B denotes elongation at a moment when the fracture of the electrolytic copper foil is initiated, and C denotes elongation at a moment when the fracture of the electrolytic copper foil is terminated in a tension test of the electrolytic copper foil, wherein the moment when the fracture of the electrolytic copper foil is initiated corresponds to the moment when the stress, which has increased with an increase of the elongation of the electrolytic copper foil, begins to decrease in the tension test, and the moment when the fracture of the electrolytic copper foil is terminated corresponds to the moment when the electrolytic copper foil is broken into two or more fragments.