Negative electrode for lithium secondary battery and lithium secondary battery comprising same

Patent metadata

Field	Value
Publication number	US-2023082675-A1
Application number	US-202217993191-A
Country	US
Kind code	A1
Filing date	Nov 23, 2022
Priority date	Nov 13, 2017
Publication date	Mar 16, 2023
Grant date	—

Abstract

A negative electrode for a lithium secondary battery including a lithium metal layer; a first protective layer formed on a surface of the lithium metal layer; and a second protective layer formed on a surface of the first protective layer opposite the lithium metal layer, wherein the first protective layer and the second protective layer are different from each other in at least one property selected from the group consisting of ion conductivity and electrolyte uptake.

First claim

1 . A negative electrode for a lithium secondary battery comprising:
a lithium metal layer; a first protective layer formed on a surface of the lithium metal layer; and a second protective layer formed on a surface of the first protective layer opposite the lithium metal layer, wherein the first protective layer and the second protective layer are different from each other in at least one property selected from the group consisting of ion conductivity and electrolyte uptake.

2 . The negative electrode for the lithium secondary battery according to claim 1 , wherein the first protective layer and the second protective layer have different modulus values from each other.

3 . The negative electrode for the lithium secondary battery according to claim 1 , wherein the electrolyte uptake of the first protective layer is 150% or more and the electrolyte uptake of the second protective layer is less than 150%.

4 . The negative electrode for the lithium secondary battery according to claim 1 , wherein the ion conductivity of the first protective layer is 10 −4 S/cm or more and the ion conductivity of the second protective layer is less than 10 −4 S/cm.

5 . The negative electrode for the lithium secondary battery according to claim 2 , wherein the modulus value of the first protective layer is less than 10 7 Pa, and the modulus value of the second protective layer is 10 7 Pa or more.

6 . The negative electrode for the lithium secondary battery according to claim 1 , wherein the first protective layer comprises (a) one or more first polymer selected from the group consisting of a first polyethylene oxide (PEO) based polymer and a first polypropylene oxide (PPO) based polymer, and (b) a first lithium salt.

7 . The negative electrode for the lithium secondary battery according to claim 6 , wherein the first polymer is at least one selected from the group consisting of PEO, PPO, copolymers of PEO and PPO, and a blending of PEO and PPO.

8 . The negative electrode for the lithium secondary battery according to claim 1 , wherein the second protective layer comprises (a) one or more second polymer selected from the group consisting of a second polyethylene oxide (PEO) based polymer and a second polypropylene oxide (PPO) based polymer, (b) a second lithium salt and (c) an oligomer comprising an acrylate functional group.

9 . The negative electrode for the lithium secondary battery according to claim 8 , wherein the second polymer is at least one selected from the group consisting of PEO, PPO, copolymers of PEO and PPO, and a blending of PEO and PPO.

10 . The negative electrode for the lithium secondary battery according to claim 8 , wherein the oligomer comprising the acrylate functional group is an oligomer having 6 acrylate functional groups.

11 . The negative electrode for the lithium secondary battery according to claim 1 , wherein the first protective layer has a thickness of 0.1 to 5 μm.

12 . The negative electrode for the lithium secondary battery according to claim 1 , wherein the second protective layer has a thickness of 0.1 to 5 μm.

13 . A lithium secondary battery comprising a positive electrode; the negative electrode of claim 1 ; and an electrolyte solution.

14 . The lithium secondary battery according to claim 13 , wherein the positive electrode comprises a sulfur compound in an active material.

Assignees

• Lg Energy Solution Ltd

Inventors

• Koh Dongwook
• Yang Doo Kyung

Classifications

• H01M4/137

  Electrodes based on electro-active polymers · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/366 Primary

  as layered products · CPC title

• H01M50/46

  Separators, membranes or diaphragms characterised by their combination with electrodes · CPC title