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.
1. A rolled copper foil for a lithium ion battery current collector, wherein a surface of the copper foil has a benzotriazole film, the benzotriazole film has a thickness of 0.6 nm or more and 4.6 nm or less, and wherein the rolled copper foil satisfies the following relationships:
40≤wet tension [mN/m]+thickness of benzotriazole film [nm]×10≤80;
0.01≤arithmetic average roughness Ra [μm]≤0.25; and
wet tension [mN/m]≥35.
2. The rolled copper foil for a lithium ion battery current collector according to claim 1 , wherein the rolled copper foil satisfies:
45≤wet tension [mN/m]+thickness of benzotriazole film [nm]×10≤75; and
wet tension [mN/m]≥39.
3. The rolled copper foil for a lithium ion battery current collector according to claim 1 , wherein the rolled copper foil satisfies an arithmetic average roughness Ra [μm]≥0.03.
4. The rolled copper foil for a lithium ion battery current collector according to claim 1 , wherein the rolled copper foil is for a negative electrode current collector of a lithium ion secondary battery.
5. A lithium ion battery comprising the rolled copper foil for a lithium ion battery current collector according to claim 1 .
6. The rolled copper foil for a lithium ion battery current collector according to claim 2 , wherein the rolled copper foil satisfies an arithmetic average roughness Ra [μm]≥0.03.
7. The rolled copper foil for a lithium ion battery current collector according to claim 2 , wherein the rolled copper foil is for a negative electrode current collector of a lithium ion secondary battery.
8. The rolled copper foil for a lithium ion battery current collector according to claim 3 , wherein the rolled copper foil is for a negative electrode current collector of a lithium ion secondary battery.
9. The rolled copper foil for a lithium ion battery current collector according to claim 4 , wherein the rolled copper foil is for a negative electrode current collector of a lithium ion secondary battery.
10. The rolled copper foil according to claim 1 , wherein the thickness of the benzotriazole film is 2.1 nm or more and 4.6 nm or less.