Copper foil having improved adhesive force, electrode including the same, secondary battery including the same, and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-2018261850-A1
Application number	US-201815914568-A
Country	US
Kind code	A1
Filing date	Mar 7, 2018
Priority date	Mar 9, 2017
Publication date	Sep 13, 2018
Grant date	—

Abstract

Provided is a copper foil. The copper foil includes a copper layer and a protective layer disposed on the copper layer, wherein a surface of the protective layer has a maximum height roughness (R max ) of 0.6 μm to 3.5 μm, a peak density (PD) of 5 to 110, and an oxygen atomic amount of 22 at % (atomic %) to 67 at %.

First claim

What is claimed is:

1 . A copper foil comprising:
a copper layer; and a protective layer disposed on the copper layer, wherein a surface of the protective layer has a maximum height roughness (R max ) of 0.6 μm to 3.5 μm, a peak density (PD) of 5 to 110, and an oxygen atomic amount of 22 at % (atomic %) to 67 at %.

2 . The copper foil of claim 1 , wherein the protective layer includes at least one of chromium, a silane compound, and a nitrogen compound.

3 . The copper foil of claim 1 , wherein the copper foil has a yield strength of 25 kgf/mm 2 or more at a room temperature of 25±15° C.

4 . The copper foil of claim 1 , wherein the copper foil has an elongation of 2% or more at a room temperature of 25±15° C.

5 . The copper foil of claim 1 , wherein the copper foil has a yield strength ratio of 0.55 kgf/mm 2 or more represented by the following Equation 1:
Yield strength ratio(kgf/mm 2 )=Yield strength(kgf/mm 2 )×Elongation value,   [Equation 1]
wherein, the elongation value has no unit.

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

7 . A secondary battery electrode comprising:
a copper foil; and an active material layer disposed on the copper foil, wherein the copper foil includes:
a copper layer; and
a protective layer disposed between the copper layer and the active material layer,
wherein a surface of the copper foil has a maximum height roughness (R max ) of 0.6 μm to 3.5 μm, a peak density (PD) of 5 to 110, and an oxygen atomic amount of 22 at % to 67 at %.

8 . The secondary battery electrode of claim 7 , wherein the protective layer includes at least one of chromium, a silane compound, and a nitrogen compound.

9 . The secondary battery electrode of claim 7 , wherein the copper foil has a yield strength of 25 kgf/mm 2 or more and an elongation of 2% or more at a room temperature of 25±15° C.

10 . A secondary battery comprising:
a cathode; an anode including the secondary battery electrode according to any one of claims 7 to 9 ; an electrolyte configured to provide an environment in which lithium ions move between the cathode and the anode; and a separator configured to electrically insulate the cathode from the anode.

11 . A method of manufacturing a copper foil, the method comprising:
forming a copper layer by running a current having a density of 40 to 80 A/dm 2 from a positive electrode plate to a rotating negative electrode drum which are disposed to be spaced apart from each other in an electrolytic solution containing copper ions; and immersing the copper layer in an antirust solution containing chromium (Cr) and forming a protective layer on the copper layer, wherein the antirust solution has a pH of 1.5 to 4.2 and a dissolved oxygen amount of less than 5 ppm.

12 . The method of claim 11 , wherein the electrolytic solution contains 70 to 90 g/L of copper ions and 80 to 120 g/L of sulfuric acid.

13 . The method of claim 11 , wherein total inorganic carbon (TIC) in the electrolytic solution is 0.05 g/L or less.

14 . The method of claim 11 , wherein a concentration of iron (Fe) ions in the electrolytic solution is 0.30 g/L or less.

15 . The method of claim 11 , wherein the forming of the copper layer includes filtering the electrolytic solution using activated carbon.

Assignees

• Ls Mtron Ltd

Inventors

• Kim Seung Min
• Jin Shan Hua

Classifications

• H01M4/661

  Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence) · CPC title

• C25D1/20

  Separation of the formed objects from the electrodes {with no destruction of said electrodes} · CPC title

• C23C22/24

  containing hexavalent chromium compounds · CPC title

• H01M4/483

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title