Copper foil having excellent heat resistance property

Patent metadata

Field	Value
Publication number	US-2021135233-A1
Application number	US-201916668735-A
Country	US
Kind code	A1
Filing date	Oct 30, 2019
Priority date	Oct 30, 2019
Publication date	May 6, 2021
Grant date	—

Abstract

Electrodeposited copper foils are described having improved thermal properties. The copper foils include a drum side and deposited side where both sides have a roughness Rz lower than 2 μm and wherein, when the electrodeposited copper foil is subjected to a thermal gravimetric analysis (TGA), the electrodeposited copper foil exhibits a primary weight increase of 105 wt. % when a primary temperature (T105 wt %) is reached during the TGA, wherein the T105 wt % is in a range of 350° C. to 501° C. The TGA characterization comprises heating at a rate of 5° C./min and an air flow at a rate of 95 mL/min. Ultrasonic welding of the copper foils to nickel foils provides an excellent weld with low detachment providing a good mechanical and electrical contact for applications such as in lithium-ion secondary batteries.

First claim

1 . An electrodeposited copper foil comprising a drum side and a deposited side;
wherein each of the drum side and the deposited side of the electrodeposited copper foil have a ten-point average roughness, Rz, in the range of 1.0 μm to less than or equal to 2 μm, and each of the drum side and the deposited side of the electrodeposited copper foil further comprise a chromium coating, wherein the electrodeposited copper foil exhibits a primary weight increase of 105 wt. %, when a primary temperature (T 105 wt % ) is reached during thermal gravimetric analysis (TGA), wherein the primary temperature (T 105 wt % ), is in a range of 350° C. to 501° C., and wherein the TGA comprises heating the electrodeposited copper foil at a rate of 5° C./min and an air flow at a rate of 95 mL/min.

2 . The electrodeposited copper foil according to claim 1 , wherein the electrodeposited copper foil exhibits a secondary weight increase of 100.1 wt. % when a secondary temperature (T 100.1 wt % ) is reached during the TGA, wherein the T 100.1 wt % is in a range of 130° C. to 230° C.

3 . The electrodeposited copper foil according to claim 2 , wherein the T 100.1 wt % is in a range of 130° C. to 200° C.

4 . (canceled)

5 . The electrodeposited copper foil according to claim 1 , wherein the electrodeposited copper foil exhibits an onset temperature (T onset ) during the TGA, wherein the T onset is in a range of 300° C. to 430° C.

6 . The electrodeposited copper foil according to claim 5 , wherein the T onset is in a range of 320° C. to 430° C.

7 . The electrodeposited copper foil according to claim 5 , wherein the electrodeposited copper foil exhibits a Weight Increase Rate (WIR) in a range of 0.068 to 0.313 wt %/° C., wherein the WIR is defined by Formula I:

W
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I
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R

=

5
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(

wt
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%

)

T

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%

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(

°
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.

)

-

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n
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I
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8 . The electrodeposited copper foil according to claim 7 wherein the WIR is in a range of 0.068 to 0.25 wt. %/° C.

9 . The electrodeposited copper foil according to claim 7 , wherein the WIR is in a range of 0.068 to 0.20 wt. %/° C.

10 . A secondary lithium-ion battery comprising the electrodeposited copper foil of claim 1 and an active material coated on the electrodeposited copper foil, wherein the electrodeposited copper foil is welded to a nickel connecting tab.

11 . (canceled)

Assignees

• Chang Chun Petrochemical Co Ltd

Inventors

• Lai Yao-Sheng
• Chou Jui-Chang

Classifications

• C25D3/04

  of chromium · CPC title

• C25D7/0614

  Strips or foils · CPC title

• C25D3/38

  of copper · CPC title

• H01M4/72

  Grids · CPC title

• H01M4/667

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