Copper foil for current collector of lithium secondary battery

Patent metadata

Field	Value
Publication number	US-11962014-B2
Application number	US-201816222066-A
Country	US
Kind code	B2
Filing date	Dec 17, 2018
Priority date	Dec 4, 2017
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

Electrodeposited copper foils having adequate puncture strength to withstand both pressure application during consolidation with negative electrode active materials during manufacture, as well as expansion/contraction during repeated charge/discharging cycles when used in a rechargeable secondary battery are described. These copper foils find specific utility as current collectors in rechargeable secondary batteries, particularly in lithium secondary battery with high capacity. Methods of making the copper foils, methods of producing negative electrode for use in lithium secondary battery and lithium secondary battery of high capacity are also described.

First claim

We claim:

1. An electrodeposited copper foil having a drum side and a deposit side, each of the deposit side and drum side comprise a grain size, wherein the difference in grain size is less than 0.55 μm and the number of voids in the electrodeposited copper foil is less than 5 per μm 2 , wherein each void in the number of voids is defined as a void having a circular diameter of at least 0.01 μm.

2. The electrodeposited copper foil of claim 1 , which copper foil has a puncture strength, wherein the puncture strength of the drum side and deposited side is at least 2.85 N.

3. The electrodeposited copper foil of claim 1 , further comprising a surface roughness (Rz) of the deposit side is less than 2.0 μm.

4. The electrodeposited coper foil of claim 1 , wherein the copper foil further comprises nickel, which nickel was electrodeposited simultaneously with the deposition of the copper foil.

5. The electrodeposited copper foil of claim 2 , wherein the area weight of the electrodeposited copper foil is in the range of 26.7-329.4 g/m 2 .

6. A negative electrode comprising a consolidated electrode active material on the electrodeposited copper foil of claim 1 .

7. A rechargeable secondary battery comprising the negative electrode of claim 6 .

8. The rechargeable secondary battery of claim 7 , in the form of a stack of alternating positive and negative electrodes separated by a separator, wherein at least one of the current collectors in the alternating stack comprises the negative electrode active material.

9. An electric vehicle (EV) comprising the rechargeable secondary battery of claim 8 .

Assignees

• Chang Chun Petrochemical Co Ltd

Inventors

• Huang Huei-Fang
• Cheng Kuei-Sen
• Lai Yao-Sheng
• Chou Jui-Chang

Classifications

• H01M4/661 Primary

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

• C25D1/04 Primary

  Wires; Strips; Foils · CPC title

• C25D3/38

  of copper · CPC title

• C25D7/0614

  Strips or foils · CPC title

• C25D7/0642

  Anodes · CPC title