ELECTRODEPOSITED COPPER FOIL WITH A UNIFORM MATTE SURFACE

1 . An electrodeposited copper foil, characterized in that:

the electrodeposited copper foil has an average thickness (T Ave ) of about 30 μm to about 400 μm;

the electrodeposited copper foil has a matte surface and a shiny surface;

the matte surface of the electrodeposited copper foil comprises a plurality of protrusions; and

a number (PA 50+ ) of the protrusions on the matte surface having flattened peaks after polishing with a surface area of 50 μm 2 or more per 1 mm 2 of the matte surface is 8.0 or less;

wherein

the average thickness is measured by a scanning electron microscope (SEM);

peaks of some protrusions on the matte surface are flattened by: a) placing the electrodeposited copper foil on a glass substrate with the matte surface in contact with the glass substrate, and b) polishing off about 1 μm of the shiny surface of the electrodeposited copper foil by using a silicon carbide sandpaper with a grit size of 1200;

the number and the surface area of the protrusions on the matte surface having flattened peaks after polishing is counted and measured by using an optical microscope having a magnifying power of 50 times or more and a resolution of at least 0.1 μm.

2 . The electrodeposited copper foil of claim 1 , wherein the matte surface of the electrodeposited copper foil has a PA 50+ per 1 mm 2 of the matte surface is 6.0 or less.

3 . The electrodeposited copper foil of claim 1 , wherein the matte surface of the electrodeposited copper foil has a uniformity factor (UF) of 5.5 μm or less, and the UF is calculated according to the equation 1 below:

UF

=

A

max

/

T

Ave

(

eq

.

1

)

wherein A max is a maximum surface area (A max ) of the protrusions on the matte surface having flattened peaks after polishing; and

T Ave is the average thickness of the electrodeposited copper foil.

4 . The electrodeposited copper foil of claim 1 , wherein the matte surface of the electrodeposited copper foil has a UF of 4.0 μm or less.

5 . A method for manufacturing the electrodeposited copper foil of claim 1 , comprising:

i) providing an electrolytic solution in an electrolytic cell;

ii) applying an electric current at a current density to an anode plate and a rotating cathode drum that are spaced apart from each other in the electrolytic solution;

iii) electrodepositing a copper foil on the rotating cathode drum; and

iv) separating the copper foil formed in step iii) to obtain an electrodeposited copper foil;

wherein

the electrodeposited copper foil has an average thickness of about 30 μm to about 400 μm;

the electrodeposition of step iii) is performed at a current density of about 30 A/dm 2 to about 100 A/dm 2 ;

the electrolytic solution comprises:

about 120 g/L to about 450 g/L of copper sulfate;

about 30 g/L to about 140 g/L of sulfuric acid;

about 0.1 ppm to about 60 ppm of chloride ion; and

about 0.1 ppm to about 50 ppm of an additive.

6 . The method of claim 5 , wherein the electrodeposition of step iii) is performed at a temperature of the electrolytic solution being about 20° C. to about 80° C.

7 . The method of claim 5 , wherein the additive in the electrolytic solution comprises gelatin, animal glue, cellulose, an organosulfonic acid or salts thereof, a nitrogen-containing cationic polymer, or mixtures thereof.

8 . The method of claim 7 , wherein the additive comprises a nitrogen-containing cationic polymer, and the nitrogen-containing cationic polymer has a weight-average molecular weight of from about 1,000 to about 10,000 g/mole.

9 . The method of claim 8 , wherein the nitrogen-containing cationic polymer is a reaction product of a diamine of Formula (I) or an imidazole of Formula (II) with an epoxide of Formula (III) or a diepoxide of Formula (IV):

wherein

R 1 , R 2 , R 3 , and R 4 are independently H or C 1 -C 3 alkyl;

R 5 is H or C 1 -C 6 alkyl;

each of R 6 , R 7 , R 8 is independently H or C 1 -C 6 alkyl, and R 7 and R 8 are optionally linked to each other to form a saturated ring;

R 9 and R 10 are independently H or C 1 -C 4 alkyl;

R 11 is a divalent linking group selected from C 2 -C 8 alkylene and C 5 -C 10 cycloalkylene, where R 11 is optionally substituted with C 1 -C 4 alkyl or OH;

A is a divalent linking group selected from C 2 -C 8 alkylene, C 5 -C 10 cycloalkylene, phenylene, and C 6 -C 20 arylene, where A is optionally substituted with C 1 -C 4 alkyl or OH;

Y is H or C 1 -C 4 alkyl;

X is halogen;

p, q, and r are each independently an integer of 0 to 10; and

n is an integer from 1 to 20.

10 . A surface-treated electrodeposited copper foil, comprising the electrodeposited copper foil of claim 1 that has at one surface of the electrodeposited copper foil has been applied with at least one surface treatment step.

11 . The surface-treated electrodeposited copper foil of claim 10 , wherein the surface treatment step includes a pickling step, a roughening step, a heat-resistant layer forming step, an antioxidant layer forming step, or an adhesion promotion layer forming step.

12 . An article, wherein the article comprises the electrodeposited copper foil of claim 1 or the surface-treated electrodeposited copper foil of claim 10 .

13 . The article of claim 12 , wherein the article is a negative electrode collector of a lithium-ion battery, a copper clad laminate, a flexible copper clad laminate, a heat dissipation plate, or a printed circuit board.