Copper foil, current collector and lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-2025297340-A1
Application number	US-202519084131-A
Country	US
Kind code	A1
Filing date	Mar 19, 2025
Priority date	Mar 19, 2024
Publication date	Sep 25, 2025
Grant date	—

Abstract

A copper foil is provided, including 5 ppm to 25 ppm silver. 0.5 ppm to 8 ppm titanium, and 5 ppm to 85 ppm sulfur. Also provided are a current collector for a lithium ion secondary battery and a lithium ion secondary battery.

First claim

1 . A copper foil, comprising 5 ppm to 25 ppm of silver, 0.5 ppm to 8 ppm of titanium and 5 ppm to 85 ppm of sulfur.

2 . The copper foil of claim 1 , comprising 5 ppm to 20 ppm of silver.

3 . The copper foil of claim 1 , comprising 0.5 ppm to 5 ppm of titanium.

4 . The copper foil of claim 1 , comprising 5 ppm to 70 ppm of sulfur.

5 . The copper foil of claim 1 , having a tensile strength ranging from 45 kg/mm 2 to 85 kg/mm 2 .

6 . The copper foil of claim 1 , having a tensile strength ranging from 60 kg/mm 2 to 80 kg/mm 2 .

7 . The copper foil of claim 1 , having an electrical conductivity of 80% IACS or more.

8 . The copper foil of claim 1 , having a first surface and an opposite second surface, wherein the first and second surfaces of the copper foil respectively have a ten-point mean roughness (Rz) of 2.5 μm or less.

9 . The copper foil of claim 1 , having an elongation of 1% to 15%.

10 . The copper foil of claim 1 , having a thickness of 3 μm to 35 μm.

11 . The copper foil of claim 1 , comprising a copper layer and a treatment layer.

12 . The copper foil of claim 11 , wherein the treatment layer is formed on at least one surface of the copper layer, and the treatment layer is formed from an organic material or an inorganic material.

13 . The copper foil of claim 12 , wherein the inorganic material comprises at least one selected from the group consisting of chromium, nickel, zinc, cobalt, manganese, and tin.

14 . The copper foil of claim 12 , wherein the organic material comprises at least one selected from the group consisting of carbon, oxygen, nitrogen, sulfur, and silicon.

15 . The copper foil of claim 12 , wherein the organic material comprises at least one selected from the group consisting of porphyrin compounds, silane compounds, benzotriazole compounds, and triazine trithiol compounds.

16 . A current collector for a lithium ion secondary battery, comprising the copper foil of claim 1 .

17 . A lithium ion secondary battery, comprising the current collector of claim 16 .

Assignees

• Chang Chun Petrochemical Co Ltd

Inventors

• Chiu Sheng-Han
• Cheng Kuei-Sen

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M4/667

  in the form of layers, e.g. coatings · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M4/661 Primary

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

• H01M10/0525

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