Method for manufacturing negative electrode for secondary battery and negative electrode for secondary battery

Patent metadata

Field	Value
Publication number	US-2019237750-A1
Application number	US-201916376439-A
Country	US
Kind code	A1
Filing date	Apr 5, 2019
Priority date	Jul 31, 2017
Publication date	Aug 1, 2019
Grant date	—

Abstract

A method of manufacturing a negative electrode for a secondary battery includes a first step of preparing a lithium metal sheet coated with a lithium metal or to which the lithium metal is adhered in a form of a thin film on a release film and wound into a roll, a second step of laminating the lithium metal sheet to allow the lithium metal to be adjacent to a negative electrode material mixture, to thereby manufacture a negative electrode in which lithium metal is laminated and a third step of applying pressure to the negative electrode. The release film is coated with silicon. The negative electrode manufacturing method uniformly laminates or bonds lithium metal which is difficult to handle on the negative electrode material mixture of the secondary battery and advantageously enhances the speed of the pre-lithiation by using the patterned lithium metal.

First claim

1 . A method of manufacturing a negative electrode for a secondary battery, the method comprising:
a first step of preparing a lithium metal sheet formed by a release film coated with a lithium metal or to which the lithium metal is adhered in a form of a thin film and wound into a roll; a second step of laminating the lithium metal sheet to allow the lithium metal to be adjacent to a negative electrode material mixture, to thereby manufacture a negative electrode in which lithium metal is laminated; and a third step of applying a pressure to the negative electrode having the lithium metal laminated thereon to manufacture a negative electrode, wherein the release film is coated with silicon.

2 . The method of claim 1 , wherein the lithium metal has a stripe, mesh, wave, circular pattern.

3 . The method of claim 2 , wherein the lithium metal has a stripe pattern, wherein the stripe pattern is produced by cutting lithium metal, which is a base material, into thin-width metals.

4 . The method of claim 1 , wherein the lithium metal has a thickness of 2 to 200 μm.

5 . The method of claim 1 , wherein the applying of pressure to the negative electrode is performed by passing the negative electrode through a pair of rollers or plates.

6 . The method of claim 5 , wherein a temperature at the time of passing through the rollers or the plates is 5 to 100° C.

7 . The method of claim 5 , wherein the pressure at the time of passing through the roller or the plate is 10 to 100 kg/cm 2 .

8 . The method of claim 1 , wherein a thickness of the release film is 5 to 50 μm.

9 . The method of claim 1 , wherein the negative electrode material mixture is prepared by applying a negative electrode slurry containing silicon oxide on a current collector and then drying and rolling the negative electrode material mixture.

10 . A method of manufacturing a secondary battery, the method comprising:
manufacturing an electrode assembly by interposing a separator between a negative electrode and a positive electrode which negative electrode is manufactured by the method according to claim 1 ; injecting an electrolyte into the electrode assembly; and aging, wherein an initial charging is started by injecting the electrolyte.

11 . The method of claim 10 , wherein the aging is performed for 12 to 72 hours.

12 . A negative electrode for a secondary cell produced by the method according to claim 1 .

13 . A secondary battery having a feature that an initial charging is started by injecting an electrolyte into an electrode assembly including a negative electrode for a secondary battery manufactured by the method according to claim 1 .

Assignees

• Lg Chemical Ltd

Inventors

• Kim Ju Ri
• Kim In Chul
• Song Joo Yong
• Kim Seok Koo

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/0435

  Rolling or calendering · CPC title

• H01M4/1395 Primary

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/0404

  by coating on electrode collectors · CPC title

• H01M4/366

  as layered products · CPC title