# US 12,763,334 B2 · Copper foil capable of preventing tear or wrinkle defects, electrode comprising the same, secondary battery comprising the same, and method for manufacturing the same

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- Number: US 12,763,334 B2
- Document ID: US12763334B2
- Status: Granted
- Kind: B2
- Application number: 18/392,730
- Filed: 2023-12-21
- Published: 2024-06-27
- Granted: 2026-10-13
- Earliest claimed: 2022-12-27
- Assignees: SK Nexilis Co., Ltd.
- Applicants: SK Nexilis Co., Ltd.
- Inventors: Shan Hua Jin; Min Seok Yoon
- Web page: https://patentgrep.com/patent/US12763334B2

## CPC

- H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)}
- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/667: {in the form of layers, e.g. coatings}
- H01M 4/75: Wires, rods or strips
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY

## Abstract

According to one embodiment of the present disclosure, there is provided a copper foil including a copper film including 99.9 wt % or more of copper, wherein the copper foil has a first stress factor in a range of 2.8 to 3.2, a second stress factor in a range of 2.5 to 3.0, and a third stress factor in a range of 3.5 to 4.5, and a method for manufacturing the copper foil.

## Claims

### Claim 1

A copper foil comprising a copper film including 99.9 wt % or more of copper,
wherein the copper foil has a first stress factor of 2.8 or more, a second stress factor of 2.5 or more, and a third stress factor of 3.5 or more,
wherein the first stress factor is calculated by Equation 1,
first
⁢
stress
⁢
factor
=
A
/
A
′
+
B
/
B
′
+
C
/
C
′
,
[
Equation
⁢
1
]
the second stress factor is calculated by Equation 2,
second
⁢
stress
⁢
factor
=
A
/
B
+
A
′
/
B
′
,
[
Equation
⁢
2
]
and
the third stress factor is calculated by Equation 3 below,
third
⁢
stress
⁢
factor
=
A
/
C
+
A
′
/
C
′
,
[
Equation
⁢
3
]
wherein A in Equation 1 is a stress at 50% elongation in a machine direction (MD direction),
A′ in Equation 1 is a stress at 50% elongation in a transverse direction (TD direction),
B in Equation 1 is a stress at 10% elongation in the MD direction,
B′ in Equation 1 is a stress at 10% elongation in the TD direction,
C in Equation 1 is a stress at 5% elongation in the MD direction, and
C′ in Equation 1 is a stress at 5% elongation in the TD direction.

### Claim 2 (depends on 1)

The copper foil of claim 1, further comprising a protective layer formed on the copper film.

### Claim 3 (depends on 2)

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