Negative electrode for secondary battery, and secondary battery including same

Patent metadata

Field	Value
Publication number	US-2026051479-A1
Application number	US-202519370611-A
Country	US
Kind code	A1
Filing date	Oct 27, 2025
Priority date	Apr 3, 2020
Publication date	Feb 19, 2026
Grant date	—

Abstract

The technology relates to a negative electrode for a secondary battery, and a secondary battery including same. The negative electrode comprises a composite material layer having a double-layer structure, but includes silicon oxide and carbon nanotubes in only one layer, such that it is possible to increase the capacity of a battery while preventing structural deterioration of the negative electrode due to changes in electrode volume during charging and discharging.

First claim

What is claimed is:

1 . A negative electrode for a secondary battery, comprising:
a current collector; and a mixture layer formed on one or both surfaces of the current collector, wherein the mixture layer has a two-layer structure in which a first mixture layer and a second mixture layer are stacked, wherein the first mixture layer includes a first carbon material and a silicon oxide as a first active materials in a weight ratio of 90:10 to 99:1 and a first needle type carbon-based conductive material as a first conductive material, wherein the second mixture layer includes a second carbon material as a second active material and a second sphere type carbon-based conductive material as a second conductive material, wherein the first mixture layer is disposed directly on the current collector, wherein the second mixture layer is disposed on a surface of the first mixture layer on which the current collector is not disposed, and wherein the silicon oxide is included only in the first mixture layer.

2 . The negative electrode of claim 1 , wherein the first conductive material includes the needle type carbon-based conductive material and a first sphere type carbon-based conductive material in a weight ratio of 0.01:5 to 1:0.5.

3 . The negative electrode of claim 1 , wherein the first mixture layer and the second mixture layer include first and second binders, respectively, and
wherein a weight ratio (B1:B2) of the first binder content (B1) to the second binder content (B2) is in a range of 1.0:1 to 3.6:1.

4 . The negative electrode of claim 3 , wherein the first mixture layer includes the first binder in an amount of 1 to 10 parts by weight based on a total weight of the first mixture layer.

5 . The negative electrode of claim 1 , wherein the first mixture layer includes:
90 to 100 parts by weight of the first carbon material and 1 to 10 parts by weight of silicon oxide as the first active materials; 0.01 to 1 parts by weight of the first needle type carbon-based conductive material and 0.5 to 5 parts by weight of the first conductive material; and 1 to 10 parts by weight of a first binder.

6 . The negative electrode of claim 1 , wherein the second mixture layer includes:
90 to 100 parts by weight of the second carbon material as the second active material; 0.5 to 5 parts by weight of the second sphere type carbon-based conductive material as the second conductive material; and 1 to 10 parts by weight of a second binder.

7 . The negative electrode of claim 1 , wherein the second sphere type carbon-based conductive material is carbon black, and
wherein the first needle type carbon-based conductive material is a carbon nanotube (CNT), a vapor-grown carbon fiber (VGCF), a carbon nanofiber (CNF), or a mixture of two or more thereof.

8 . The negative electrode of claim 1 ,
wherein a ratio (D1 D2) of an average thickness (D1) of the first mixture layer to an average thickness of the second mixture layer (D2) is in a range of a thickness ratio of 0.1:1 to 0.9:1.

9 . A secondary battery comprising:
a negative electrode for a secondary battery according to claim 1 ; a positive electrode containing lithium-containing oxide as an active material; and a separator interposed between the negative electrode and the positive electrode.

10 . The secondary battery of claim 9 , wherein the lithium-containing oxide has a structure represented by one of following chemical formulas:

11 . The negative electrode of claim 1 , wherein the needle type carbon-based conductive material is included in only the first mixture layer.

12 . The negative electrode of claim 1 , wherein the needle type carbon-based conductive material has an aspect ratio in a range of 50 to 650.

13 . The negative electrode of claim 1 , wherein the needle type carbon-based conductive material has an aspect ratio in a range of 100 to 300.

14 . The negative electrode of claim 1 , wherein the needle type carbon-based conductive material comprises a carbon nanotube (CNT).

15 . The negative electrode of claim 1 , wherein the needle type carbon-based conductive material comprises a vapor-grown carbon fiber (VGCF).

16 . The negative electrode of claim 1 , wherein the needle type carbon-based conductive material comprises a carbon nanofiber (CNF).

Assignees

• Lg Energy Solution Ltd

Inventors

• Sung Ki Won
• Lee Eun Ju
• Kim Ju Ri

Classifications

• H01M2004/028

  Positive electrodes · CPC title

• H01M2004/027

  Negative electrodes · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · 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 Primary

  for inserting or intercalating light metals · CPC title