Anode for lithium secondary battery, method for manufacturing lithium secondary battery, and lithium secondary battery

Patent metadata

Field	Value
Publication number	US-2024258512-A1
Application number	US-202218561099-A
Country	US
Kind code	A1
Filing date	Nov 22, 2022
Priority date	Nov 29, 2021
Publication date	Aug 1, 2024
Grant date	—

Abstract

A negative electrode for a lithium secondary battery, a method for manufacturing a lithium secondary battery, and a lithium secondary battery are disclosed. The negative electrode includes a negative electrode current collector; a negative electrode active material layer on one surface or both surfaces of the current collector; and an electrolyte solution dissolution layer on a surface of the negative electrode active material layer opposite to a surface of the negative electrode active material layer facing the negative electrode current collector layer. The electrolyte solution dissolution layer has a thickness of 0.1 μm or more and 5 μm or less. The electrolyte solution dissolution layer comprises a binder copolymer comprising a monomer unit comprising a fluoro group, and the monomer unit is present in an amount of 5 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the binder copolymer.

First claim

1 . A negative electrode for a lithium secondary battery, comprising:
a negative electrode current collector layer; a negative electrode active material layer on one surface or both surfaces of the negative electrode current collector layer; and an electrolyte solution dissolution layer on a surface of the negative electrode active material layer opposite to a surface of the negative electrode active material layer brought into contact with facing the negative electrode current collector layer, wherein the electrolyte solution dissolution layer has a thickness of 0.1 μm or more and 5 μm or less, and wherein the electrolyte solution dissolution layer comprises a binder copolymer comprising a monomer unit comprising a fluoro group, and wherein the monomer unit is present in an amount of 5 parts by weight or more and 20 parts by weight or less based on 100 parts by weight of the binder copolymer.

2 . The negative electrode of claim 1 , wherein the monomer unit comprises a perfluoro olefin.

3 . The negative electrode of claim 1 , wherein the electrolyte solution dissolution layer further comprises an acrylic polymer, and wherein the binder copolymer is present in an amount of 1 part by weight or more and 20 parts by weight or less based on 100 parts by weight of the electrolyte solution dissolution layer.

4 . The negative electrode of claim 1 , wherein the negative electrode active material layer comprises: a silicon-containing active material; a negative electrode conductive material; and a negative electrode binder, and
wherein the silicon-containing active material comprises one or more selected from the group consisting of SiOx, wherein x=0, SiOx, wherein 0<x<2, SiC, a metal impurity, and a Si alloy.

5 . The negative electrode of claim 4 , wherein the silicon-based silicon-containing active material comprises one or more selected from the group consisting of SiOx, wherein x=0, and SiOx, wherein 0<x<2, and comprises 70 parts by weight or more of the SiOx, wherein x=0, based on 100 parts by weight of the silicon based silicon-containing active material.

6 . The negative electrode of claim 1 , wherein the negative electrode current collector layer has a thickness of 1 μm or more and 100 μm or less, and
wherein the negative electrode active material layer has a thickness of 20 μm or more and 500 μm or less.

7 . A method for manufacturing a lithium secondary battery, the method comprising:
forming a negative electrode current collector layer and a negative electrode active material layer on one surface or both surfaces of the negative electrode current collector layer; forming an electrolyte solution dissolution layer by coating a surface of the negative electrode active material layer opposite to a surface of the negative electrode active material layer facing the negative electrode current collector layer with an electrolyte solution dissolution layer composition to form a negative electrode for the lithium secondary battery; transferring lithium metal to a surface of the electrolyte solution dissolution layer opposite to a surface of the electrolyte solution dissolution layer facing the negative electrode active material layer; forming a positive electrode current collector layer and a positive electrode active material layer on one surface or both surfaces of the positive electrode current collector layer to form a positive electrode for a lithium secondary battery; laminating a separator between the negative electrode and the positive electrode and placing the resulting laminate in a battery pouch; and pre-lithiating the negative electrode by introducing an electrolyte solution into the battery pouch.

8 . The method of claim 7 , wherein the pre-lithiating of the negative electrode by introducing the electrolyte solution into the battery pouch is performed under a pressurized condition of 5 kgf/cm 2 to 20 kgf/cm 2 under a temperature condition of 60° C. to 80° C.

9 . The method of claim 7 , wherein a time of completing the pre-lithiation in the pre-lithiating of the negative electrode by introducing the electrolyte solution into the battery pouch is 6 hours and more and 24 hours or less.

10 . The method of claim 7 , wherein the transferring of the lithium metal to the surface of the electrolyte solution dissolution layer opposite to the surface of the electrolyte solution dissolution layer facing the negative electrode active material layer comprises preparing a transfer laminate comprising a substrate layer and lithium metal provided on the substrate layer;
laminating the transfer laminate on the electrolyte solution dissolution layer wherein a surface opposite to a surface of the lithium metal facing the substrate layer faces a surface opposite to a surface of the electrolyte solution dissolution layer facing the negative electrode active material layer; and removing the substrate layer.

11 . The method of claim 10 , wherein a release layer is formed on the surface of the transfer laminate with which the substrate layer and the lithium metal are brought into contact.

12 . The method of claim 7 , wherein the lithium metal has a thickness of 1 μm or more and 10 μm or less.

13 . A lithium secondary battery manufactured by the method according to claim 7 .

Assignees

• Lg Energy Solution Ltd

Inventors

• Jeon Seoyoung
• Kim Sarah
• Lee Ilha
• Joo Mun Kyu
• Kwon Yohan
• Chae Jonghyun

Classifications

• H01M4/044

  Activating, forming or electrochemical attack of the supporting material · CPC title

• H01M10/049

  Processes for forming or storing electrodes in the battery container · CPC title

• H01M50/105

  Pouches or flexible bags · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title