Negative electrode including first negative electrode active material layer and second negative electrode active material layer having polymer coating layer on a surface of the second negative electrode active material and lithium, method of producing the same and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-12107263-B2
Application number	US-201916982343-A
Country	US
Kind code	B2
Filing date	Mar 18, 2019
Priority date	Apr 17, 2018
Publication date	Oct 1, 2024
Grant date	Oct 1, 2024

Abstract

A negative electrode for a lithium secondary battery, a method of producing the negative electrode, a method of producing a pre-lithiated negative electrode by pre-lithiation of the negative electrode, and a lithium secondary battery including the negative electrode. The negative electrode can increase the capacity of a battery and improve the electrochemical performance by securing the initial reversibility of a negative electrode by pre-lithiation, and allow lithium ions to be diffused into a negative electrode active material layer during pre-lithiation without being lost.

First claim

The invention claimed is:

1. A negative electrode for a lithium secondary battery, comprising:
a negative electrode current collector;
a first negative electrode active material layer on a surface of the negative electrode current collector and comprising a first negative electrode active material; and
a second negative electrode active material layer adjacent to a surface of the first negative electrode active material layer and comprising a second negative electrode active material, and a polymer coating layer on a surface of the second negative electrode active material,
wherein the first negative electrode active material comprises a mixture of a silicon-based negative electrode active material and a carbon-based negative electrode active material, in which a weight ratio of the silicon-based negative electrode active material to the carbon-based negative electrode active material is 1:99 to 50:50,
wherein the second negative electrode active material layer further comprises lithium,
wherein the second negative electrode active material consists of lithiated graphene, and
wherein the polymer coating layer comprises one or more selected from the group consisting of polymethyl methacrylate, polyvinyl alcohol, polyacrylic acid, polyethylene, polypropylene, polyethylene terephthalate, polycarbonate, polyacrylate, polyethylene naphthalate, polyethersulfone and polysulfone.

2. A lithium secondary battery, comprising the negative electrode for a lithium secondary battery of claim 1 .

3. A method of producing the negative electrode for the lithium secondary battery of claim 1 , comprising the steps of:
forming the first negative electrode active material layer comprising the first negative electrode active material on the surface of the negative electrode current collector;
forming the polymer coating layer on the surface of the second negative electrode active material; and
forming the second negative electrode active material layer on the surface of the first negative electrode active material layer, which the second negative electrode active material layer comprises the second negative electrode active material having the surface on which the polymer coating layer is formed, wherein the second negative electrode active material layer further comprises lithium.

Assignees

• Lg Chemical Ltd
• Lg Energy Solution Ltd

Inventors

• Chae Oh Byong
• Woo Sang Wook
• Kim Je Young

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/364

  as mixtures · CPC title