Easily handleable electrolytic copper foil, electrode comprising the same, secondary battery comprising the same, and method for manufacturing the same

Patent metadata

Field	Value
Publication number	US-10811689-B2
Application number	US-201715696360-A
Country	US
Kind code	B2
Filing date	Sep 6, 2017
Priority date	Oct 12, 2016
Publication date	Oct 20, 2020
Grant date	Oct 20, 2020

Abstract

An easily handleable electrolytic copper foil securing a highly durable secondary battery, an electrode including same, a secondary battery including same, and a method of manufacturing same. The electrolytic copper foil including first and second surfaces includes a copper layer including a matte surface facing the first surface and a shiny surface facing the second surface, a first protective layer formed on the matte surface of the copper layer, and a second protective layer formed on the shiny surface of the copper layer. A coefficient of thermal expansion of the electrolyte copper foil measured using thermomechanical analyzer while heating the electrolytic copper foil from 30 to 190° C. at 5° C./min ranges from 16 to 22 μm/(m·° C.), tensile strength of the electrolytic copper foil measured after heat treatment at 190° C., ranges from 21 to 36 kgf/mm2, and weight deviation of the electrolytic copper foil is 5% or less.

First claim

What is claimed is:

1. An electrolytic copper foil, which includes a first surface and a second surface opposite the first surface, the electrolytic copper foil comprising:
a copper layer including a matte surface facing the first surface and a shiny surface facing the second surface;
a first protective layer on the matte surface of the copper layer; and
a second protective layer on the shiny surface of the copper layer,
wherein:
a coefficient of thermal expansion of the electrolytic copper foil, which is measured using a thermomechanical analyzer (TMA) while heating the electrolytic copper foil from 30° C. to 190° C. at a speed of 5° C./min, ranges from 16 to 22 μm/(m·° C.),
a tensile strength of the electrolytic copper foil, which is measured after a heat treatment at a temperature of 190° C. for 1 hour, ranges from 21 to 36 kgf/mm 2 ,
a weight deviation of the electrolytic copper foil is 5% or less,
a peak count (Pc) of each of the first and second surfaces of the electrolytic copper foil ranges from 3 to 92, and
each of the first and second surfaces has a surface roughness (R z ) of 3.5 μm or less.

2. The electrolytic copper foil of claim 1 , having an elongation of 3% or more at room temperature.

3. The electrolytic copper foil of claim 1 , wherein each of the first and second protective layers includes at least one of chromium (Cr), a silane compound, and a nitrogen compound.

4. The electrolytic copper foil of claim 1 , having a thickness of 4 to 30 μm.

5. The electrolytic copper foil of claim 1 , having a coefficient of thermal expansion of 17.3 to 22 μm/(m·° C.).

6. A secondary battery electrode comprising:
an electrolytic copper foil including a first surface and a second surface opposite the first surface; and
a first active material layer on the first surface of the electrolytic copper foil,
wherein the electrolytic copper foil comprises:
a copper layer including a matte surface facing the first surface and a shiny surface facing the second surface;
a first protective layer on the matte surface of the copper layer; and
a second protective layer on the shiny surface of the copper layer,

wherein a coefficient of thermal expansion of the electrolytic foil, which is measured using a TMA while heating the electrolytic copper foil from 30° C. to 190° C. at a speed of 5° C./min, ranges from 16 to 22 μm/(m·° C.),
wherein a tensile strength of the electrolytic copper foil, which is measured after a heat treatment at a temperature of 190° C. for 1 hour, ranges from 21 to 36 kgf/mm 2 ,
wherein a weight deviation of the electrolytic copper foil is 5% or less,
wherein a peak count (Pc) of each of the first and second surfaces of the electrolytic copper foil ranges from 3 to 92, and
wherein each of the first and second surfaces has a surface roughness (R z ) of 3.5 μm or less.

7. The secondary battery electrode of claim 6 , wherein the first active material layer includes at least one active material selected from the group consisting of carbon, a metal (Me) such as Si, Ge, Sn, Li, Zn, Mg, Cd, Ce, Ni, or Fe, an alloy containing the metal (Me), an oxide of the metal (MeO x ), and a composite of the metal (Me) and carbon.

8. The secondary battery electrode of claim 6 , wherein the first active material layer comprises Si.

9. The secondary battery electrode of claim 6 , further comprising a second active material layer on the second protective layer.

10. A secondary battery comprising:
a cathode;
an anode including a secondary battery electrode;
an electrolyte configured to provide an environment in which lithium ions may move between the cathode and the anode; and
a separator configured to electrically insulate the cathode from the anode,
wherein the secondary battery electrode comprises:
an electrolytic copper foil including a first surface and a second surface opposite the first surface; and
a first active material layer on the first surface of the electrolytic copper foil,

wherein the electrolytic copper foil comprises:
a copper layer including a matte surface facing the first surface and a shiny surface facing the second surface;
a first protective layer on the matte surface of the copper layer; and
a second protective layer on the shiny surface of the copper layer,

wherein a coefficient of thermal expansion of the electrolytic foil, which is measured using a TMA while heating the electrolytic copper foil from 30° C. to 190° C. at a speed of 5° C./min, ranges from 16 to 22 μm/(m·° C.),
wherein a tensile strength of the electrolytic copper foil, which is measured after a heat treatment at a temperature of 190° C. for 1 hour, ranges from 21 to 36 kgf/mm 2 ,
wherein a weight deviation of the electrolytic copper foil is 5% or less,
wherein a peak count (Pc) of each of the first and second surfaces of the electrolytic copper foil ranges from 3 to 92, and
wherein each of the first and second surfaces has a surface roughness (R z ) of 3.5 μm or less.

Assignees

• Ls Mtron Ltd
• Kcf Tech Co Ltd

Inventors

• Kim Seung Min

Classifications

• C25D1/00

  Electroforming · CPC title

• C25D1/20

  Separation of the formed objects from the electrodes {with no destruction of said electrodes} · CPC title

• C25D3/58

  containing more than 50% by weight of copper · CPC title

• C25D1/04

  Wires; Strips; Foils · CPC title

• H01M10/052

  Li-accumulators · CPC title