# US 2025/0096280 A1 · Current collector, electrode and lithium-ion secondary battery for electrical storage device, and method for manufacturing current collector

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- Number: US 2025/0096280 A1
- Document ID: US20250096280A1
- Status: Published application
- Kind: A1
- Application number: 18/729,348
- Filed: 2022-01-17
- Published: 2025-03-20
- Earliest claimed: 2022-01-17
- Assignees: TDK Corporation
- Applicants: TDK Corporation
- Inventors: Mingyu CHEN; Makoto ENDO; Yoshihiro KANBAYASHI; Takasi SATOU; Natsumi KOZAI; Yoshihiko TANABE; Syuji TSUKAMOTO; Miyuki YANAGIDA
- Web page: https://patentgrep.com/patent/US20250096280A1

## CPC

- H01M 4/668: {Composites of electroconductive material and synthetic resins}
- H01M 4/0404: {by coating on electrode collectors}
- H01M 4/66: Selection of materials
- H01M 4/661: {Metal or alloys, e.g. alloy coatings (H01M4/669 take precedence)}
- H01M 4/667: {in the form of layers, e.g. coatings}
- H01M 10/052: Li-accumulators
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A current collector including: a resin layer having first and second surfaces on opposites sides; and a metal layer including copper. The metal layer includes a first metal layer located on a side of the first surface of the resin layer. A yield stress σY1 of the current collector is smaller than a tensile fracture stress σB2 of the resin layer. The yield stress σY1 [MPa] is obtained by expressions (1) and (2) from a resin layer yield stress σY2 [MPa], a resin layer thickness D2 [μm], a yield stress σY3 [MPa] of the metal layer, and a thickness D3 [μm] of the metal layer: σ ⁢ Y ⁢ 1 = A × σ ⁢ Y ⁢ 3 + ( 1 - A ) × σ ⁢ Y ⁢ 2 ( 1 ) A = D ⁢ 3 / ( D ⁢ 2 + D ⁢ 3 ) . ( 2 ) The yield stress σY3 [MPa] is obtained by the following expression (3) from a half-value width β [°] of an X-ray diffraction peak having the highest intensity in an X-ray diffraction pattern of the metal layer σ ⁢ Y ⁢ 3 = ( - 103 + 1 ⁢ 6 ⁢ 44 × √ β ) . ( 3 )

## Claims

### Claim 1

A current collector comprising:
a resin layer having a first surface and a second surface located on a side opposite to the first surface; and
a metal layer including copper,
wherein the metal layer includes a first metal layer located on a side of the first surface of the resin layer,
wherein a yield stress σY1 of the current collector is smaller than a tensile fracture stress σB2 of the resin layer,
wherein the yield stress σY1 [MPa] of the current collector is a value obtained by the following expressions (1) and (2) from a yield stress σY2 [MPa] of the resin layer, a thickness D2 [μm] of the resin layer, a yield stress σY3 [MPa] of the metal layer, and a thickness D3 [μm] of the metal layer, and
σ
⁢
Y
⁢
1
=
A
×
σ
⁢
Y
⁢
3
+
(
1
-
A
)
×
σ
⁢
Y
⁢
2
(
1
)
A
=
D
⁢
3
/
(
D
⁢
2
+
D
⁢
3
)
(
2
)
wherein the yield stress σY3 [MPa] of the metal layer is a value obtained by the following expression (3) from a half-value width β [°] of an X-ray diffraction peak having the highest intensity in an X-ray diffraction pattern of the metal layer.
σ
⁢
Y
⁢
3
=
(
-
103
+
1
⁢
6
⁢
44
×
√
β
)
(
3
)

### Claim 2 (depends on 1)

The current collector according to claim 1, wherein the metal layer further includes a second metal layer located on a side of the second surface of the resin layer.

### Claim 3 (depends on 1)

The current collector according to claim 1, wherein the metal layer includes copper as a main component.

### Claim 4 (depends on 1)

The current collector according to claim 1, wherein the thickness D2 of the resin layer is 4 μm or more and 6 μm or less.

### Claim 5 (depends on 1)

The current collector according to claim 1, wherein the thickness D3 of the metal layer is 0.1 μm or more and 3 μm or less.

### Claim 6 (depends on 1)

The current collector according to claim 1, wherein the half-value width β is 0.25° or less.

### Claim 7 (depends on 1)

The current collector according to claim 1, wherein the thickness D2 of the resin layer and the thickness D3 of the metal layer satisfy the following expression.
0.02
≦
D
⁢
3
/
(
D
⁢
2
+
D
⁢
3
)
≦
0.44

### Claim 8 (depends on 1)

The current collector according to claim 1, further comprising an intervening layer between the first surface of the resin layer and the first metal layer, the intervening layer including a metal other than copper as a main component.

### Claim 9 (depends on 1)

The current collector according to claim 1, wherein the resin layer includes at least any one of polyethylene terephthalate, polyimide, polypropylene, polycarbonate, polyamide, and polyvinyl chloride.

### Claim 10 (depends on 1)

An electrode for a power storage device comprising:
a current collector according to claim 1; and
an active material layer located on a side of the metal layer opposite to the resin layer.

### Claim 11 (depends on 10)

A lithium ion secondary battery comprising:
a positive electrode;
a negative electrode;
a separator disposed between the negative electrode and the positive electrode; and
a non-aqueous electrolyte including lithium ions,
wherein the negative electrode is the electrode for a power storage device according to claim 10.

### Claim 12

A method for manufacturing a current collector that has a laminated structure that includes a resin layer and a metal layer including copper, the method comprising a step of designing a yield stress and a thickness of each of layers constituting the laminated structure such that a yield stress σY1 of the current collector is smaller than a tensile fracture stress σB2 of the resin layer.

### Claim 13 (depends on 12)

The method for manufacturing a current collector according to claim 12, wherein the step of designing includes a step of designing a yield stress σY3 of the metal layer on the basis of a crystal grain size of the metal layer or a half-value width β of an X-ray diffraction peak having the highest intensity in an X-ray diffraction pattern of the metal layer.

### Claim 14 (depends on 13)

The method for manufacturing a current collector according to claim 13, wherein the step of designing a yield stress σY3 of the metal layer includes a step of deriving a relational expression between the yield stress σY3 of the metal layer and the half-value width β.

### Claim 15 (depends on 13)

The method for manufacturing a current collector according to claim 13, wherein, in the step of designing a yield stress σY3 of the metal layer, the yield stress σY3 [MPa] of the metal layer is designed on the basis of the half-value width β [°] and the following expression.
σ
⁢
Y
⁢
3
=
(
-
103
+
1
⁢
6
⁢
44
×
√
β
)