Electrolytic copper foil having excellent handling characteristics in postprocessing, and manufacturing method therefor
The present invention relates to an electrolytic copper foil having excellent handling characteristics in the manufacture of copper foil and in post-processing for manufacturing a secondary battery. The present invention provides an electrolytic copper foil having a first surface and a second surface, wherein the texture coefficient of the ( 220 ) plane of the electrolytic copper foil is 0.4-1.32, the difference (|Δ(Rz/Ra)|) between Rz/Ra on the first surface and Rz/Ra on the second surface, of the electrolytic copper foil, is less than 2.42, and the difference (|ΔPD|) in peak density (PD) between the first surface and the second surface, of the electrolytic copper foil, is 96 ea or less.
1. An electrolytic copper foil having a first surface and a second surface, wherein
a texture coefficient of (220) plane of the electrolytic copper foil defined by Equation 1 below is 0.4 to 1.32,
TC
(
220
)
=
I
(
220
)
I
0
(
220
)
1
n
∑
I
(
hkl
)
I
0
(
hkl
)
(
Equation
1
)
a difference (|Δ(Rz/Ra)|) between Rz/Ra at the first surface of the electrolytic copper foil and Rz/Ra at the second surface of the electrolytic copper foil is less than 2.42, and
a difference (|ΔPD|) between a peak density (PD) at the first surface of the electrolytic copper foil and a peak density (PD) at the second surface of the electrolytic copper foil is 96 ea or less.
2. The electrolytic copper foil according to claim 1 , wherein
the second surface is an M surface, and
Rz/Ra at the second surface is 4.2 to 9.0.
3. The electrolytic copper foil according to claim 2 , wherein
the first surface is an S surface, and
Rz/Ra at the S surface of the electrolytic copper foil is 5.1 to 6.8.
4. The electrolytic copper foil according to claim 1 , wherein the electrolytic copper foil has a tensile strength, measured at room temperature, of 30 to 65 kgf/mm 2 .
5. The electrolytic copper foil according to claim 1 , wherein the electrolytic copper foil has an elongation, measured at room temperature, of 3% or more.
6. The electrolytic copper foil according to claim 1 , wherein the electrolytic copper foil has a lateral weight deviation of 5% or less.
7. The electrolytic copper foil according to claim 1 , wherein an arithmetic mean of measured heights of corners of four protruding incision portions of the electrolytic copper foil, formed by incising electrolytic copper foil in a form of a cross having a size of 8 cm×8 cm so as to be vertically divided into two parts, is less than 10 mm.
8. The electrolytic copper foil of claim 1 , wherein the electrolytic copper foil is manufactured by:
buffing a surface of a rotary negative electrode drum using a brush having a grit of 500 # to 3000 #;
electrodepositing the copper foil on the buffed rotary negative electrode drum by applying electric current between a positive electrode plate and the buffed rotary negative electrode drum, wherein the positive electrode plate and the buffed rotary negative electrode drum are disposed in an electrolytic solution and spaced apart from each other; and
winding the electrodeposited copper foil,
wherein the electrolytic solution comprises 70 to 90 g/L of copper ions, 80 to 120 g/L of sulfuric acid, 10 to 20 ppm of chlorine ions, 3 to 12 ppm of a sulfide-based compound, 25 to 50 ppm of molybdenum (Mo), and 5 to 25 ppm of polyethylene glycol (PEG).
9. The electrolytic copper foil of claim 8 , wherein the sulfide-based compound is selected from a group consisting of bis-(sodium sulfopropyl) disulfide (SPS), 3-mercapto 1-propane sulfonate (MPS), and 3-(benzothiazolyl-2-mercapto)-propyl-sulfonate (ZPS).
10. The electrolytic copper foil of claim 8 , wherein the sulfide-based compound is SPS.