Copper foil having excellent adhesive strength, electrode comprising same, secondary battery comprising same, and manufacturing method therefor

1. A copper foil comprising:

a copper layer; and

an anticorrosive film disposed on the copper layer, wherein the copper foil has a Young's modulus of 3800 to 4600 kgf/mm 2 , a modulus bias factor (MBF) of 0.06 to 0.11, and a degree of increase of standard stretching, which is a ratio of elongation after heat treatment at 200° C. for 30 minutes to elongation before heat treatment, of 2.6 to 5.4,

wherein the modulus bias factor (MBF) is calculated using Equation 1 below,

MBF=(maximum modulus value−minimum modulus value)/(average modulus value)  [Equation 1]

where, in a case in which the Young's modulus of the copper foil is measured three times at three points on the copper foil in a lateral direction thereof, the Young's modulus at a point at which an average value thereof is the lowest is the minimum modulus value, the Young's modulus at a point at which the average value thereof is the highest is the maximum modulus value, and an overall average of the Young's modulus measured at the three points is the average modulus value, and,

wherein the copper foil has a (220) plane, and a texture coefficient (TC(220)) of the (220) plane is 0.48 to 1.28.

2. The copper foil according to claim 1 , wherein the copper foil has a yield strength of 21 to 63 kgf/mm 2 at a normal temperature of 23±3° C.

3. The copper foil according to claim 1 , wherein the copper foil has a maximum height roughness (Rmax) of 0.8 μm to 3.5 μm.

4. The copper foil according to claim 1 , wherein the anticorrosive film comprises at least one of chrome, a silane compound, or a nitrogen compound.

5. The copper foil according to claim 1 , wherein the copper foil has a thickness of 4 μm to 30 μm.

6. An electrode for secondary batteries, the electrode comprising:

the copper foil according to any one of claim 1 ; and

an active-material layer disposed on the copper foil.

7. A secondary battery comprising:

a cathode;

an anode disposed so as to be opposite the cathode;

an electrolyte disposed between the cathode and the anode for providing an environment in which lithium ions are movable therebetween; and

a separator for electrically isolating the cathode and the anode from each other, wherein

the anode comprises:

the copper foil according to any one of claim 1 ; and

an active-material layer disposed on the copper foil.

8. A flexible copper clad laminate comprising:

a polymer film; and

the copper foil according to any one of claim 1 , the copper foil being disposed on the polymer film.

9. A method of manufacturing the copper foil of claim 1 , the method comprising:

electrically conducting an electrode plate and a rotary electrode drum, disposed in an electrolytic solution comprising copper ions in a state of being spaced apart from each other, with a current density of 40 to 80 A/dm 2 in order to form a copper layer, wherein

the electrolytic solution comprises:

70 to 90 g/L of copper ions;

50 to 150 g/L of sulfuric acid;

0.05 g/L or less of carbon;

1.0 mg/L or less of chlorine (Cl); and

25 mg/L or less of molybdenum (Mo).

10. The method according to claim 9 , wherein variation in the current density in the rotary electrode drum in a lateral direction thereof is 3% or less.

11. The method according to claim 9 , wherein the electrolytic solution has a flow rate of 41 to 45 m 3 /hour.

12. The method according to claim 9 , further comprising soaking the copper layer in an anticorrosive solution.

13. The method according to claim 9 , wherein the anticorrosive solution comprises chrome (Cr).