Negative electrode for lithium secondary battery, method for pre-lithiation thereof, and lithium secondary battery including same

Patent metadata

Field	Value
Publication number	US-2021218016-A1
Application number	US-201917254516-A
Country	US
Kind code	A1
Filing date	Jul 4, 2019
Priority date	Jul 6, 2018
Publication date	Jul 15, 2021
Grant date	—

Abstract

A negative electrode for a lithium secondary battery, a negative electrode in which the negative electrode is pre-lithiated, a method of manufacturing the negative electrode, and a lithium secondary battery including the negative electrode The pre-lithiated negative electrode may increase the capacity and improve the electrochemical performance of a lithium secondary battery by securing the initial reversibility of a negative electrode.

First claim

1 . A negative electrode for a lithium secondary battery comprising:
a first negative electrode active material layer on a surface of a negative electrode current collector, wherein the first negative electrode active material layer comprises a first negative electrode active material; a lithium metal layer on a surface of the first negative electrode active material layer, wherein the lithium metal layer comprises lithium metal; and a second negative electrode active material layer on a surface of the lithium metal layer, wherein the second negative electrode active material layer comprises a second negative electrode active material.

1 . The negative electrode for a lithium secondary battery of claim 1 , wherein the lithium metal layer consists of lithium metal powder or a lithium metal foil.

3 . The negative electrode for a lithium secondary battery of claim 1 , wherein the first negative electrode active material and the second negative electrode active material are each independently a mixture of a silicon-based negative electrode active material and a carbon-based negative electrode active material.

4 . The negative electrode for a lithium secondary battery of claim 1 , wherein the first negative electrode active material layer and the second negative electrode active material layer each independently comprise a silicon-based negative electrode active material and a carbon-based negative electrode active ma terial at a weight ratio of 1:99 to 50:50.

5 . A method for pre-lithiation of a negative electrode for a lithium secondary battery, the method comprising:
forming a first negative electrode active material layer on a surface of a negative electrode current collector: forming a lithium metal layer comprising a lithium metal on a surface of the first negative electrode active material layer; forming a second negative electrode active material layer on a surface of the lithium metal layer; and impregnating, the resulting negative electrode for the lithium secondary battery with a pre-lithiation solution to perform pre-lithiation.

6 . The method of claim 5 , wherein the pre-lithiation solution comprises an ionizable lithium salt and an organic solvent.

7 . The method of. claim 5 , wherein the impregnation is performed at a temperature of 10° C to 200° C. for 2 hours to 48 hours.

8 . The method of claim 5 , wherein the impregnation is performed at a temperature of 20° C. to 70° C. for 2 hours to 36 hours.

9 . A method of manufacturing a lithium secondary battery the method comprising:
forming a first negative electrode active material layer on a surface of a negative electrode current collector; forming a lithium metal layer comprising lithium metal on a surface of the first negative electrode active material layer; forming a second negative electrode active material layer on a surface of the lithium metal layer to manufacture a negative electrode for the lithium secondary battery; manufacturing an electrode assembly comprising the negative electrode, a. positive electrode, and a separator; inserting the electrode assembly in a battery case; injecting an electrolyte solution into the battery case; and impregnating the electrode assembly with the electrolyte solution by maintaining the electrode assembly at a temperature of 10° C. to 200° C. for 2 hours to 48 hours.

10 . (canceled)

Assignees

• Lg Chemical Ltd

Inventors

• Chae Oh Byong
• Woo Sang Wook
• Kim Ye Ri

Classifications

• Y02E60/10

  Energy storage using batteries · CPC title

• H01M10/052

  Li-accumulators · CPC title

• H01M10/049

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

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M10/058

  Construction or manufacture · CPC title