ROLLED COPPER FOIL FOR LITHIUM ION BATTERY CURRENT COLLECTOR, AND LITHIUM ION BATTERY

Provided is a rolled copper foil for a lithium ion battery current collector, which has good adhesion to a negative electrode active material, generates less metal powder during ultrasonic welding, and has a rust prevention property. In the rolled copper foil for a lithium ion battery current collector, a surface of the copper foil has a BTA film, the BTA film has a thickness of 0.6 nm or more and 4.6 nm or less, and the rolled copper foil satisfies the following relationships: 40≤wet tension [mN]/m]+thickness of BTA film [nm]×10≤80; 0.01≤arithmetic average roughness Ra [μm]≤0.25; and wet tension [mN/m]≥35.