Conductive agent, electrode including the conductive agent, and secondary battery including the electrode

Patent metadata

Field	Value
Publication number	US-12322808-B2
Application number	US-202017604577-A
Country	US
Kind code	B2
Filing date	May 12, 2020
Priority date	May 15, 2019
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

A conductive agent includes a first particle and a second particle, wherein the first particle includes a secondary particle structure in which graphene sheets are connected to each other, the first particle includes a plurality of graphene sheets arranged in different directions, and the second particle is a carbon nanotube. An electrode including the conductive agent, and a secondary battery including the electrode are also provided.

First claim

The invention claimed is:

1. An electrode comprising:
a conductive agent comprising a first particle and a second particle,
wherein the first particle comprises a secondary particle structure in which graphene sheets are connected to each other,
the first particle comprises a plurality of graphene sheets arranged in different directions,
the second particle is a carbon nanotube,
wherein a weight ratio of the first particles to the second particle ranges from 2:8 to 5:5, and
wherein the plurality of graphene sheets have a lateral size of 10 nm to 200 nm.

2. The electrode of claim 1 , wherein an oxygen content of the first particle is in a range of 1 wt % to 10 wt % based on a total weight of the first particle.

3. The electrode of claim 1 , wherein the first particle has a D/G peak ratio of 0.9 to 2.0 during Raman spectrum measurement.

4. The electrode of claim 1 , wherein the first particle has a value calculated by Equation 1 of 0 to 0.2:

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a

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1

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wherein, in Equation 1, a is a specific surface area (m 2 /g) of the first particle which is measured by a nitrogen adsorption Brunauer-Emmett-Teller (BET) method, and b is an iodine adsorption value (mg/g) of the first particle.

5. The electrode of claim 1 , further comprising a connection portion connected to at least a part of the graphene sheets of the plurality of graphene sheets,
wherein the connection portion has a non-graphene shape.

6. The electrode of claim 5 , wherein at least a portion of each of the plurality of graphene sheets is connected to the connection portion.

7. The electrode of claim 1 , wherein the plurality of graphene sheets have an average thickness of 0.34 nm to 10 nm.

8. The electrode of claim 1 , wherein the first particle has a specific surface area (m 2 /g) measured by a nitrogen adsorption BET method of 200 m 2 /g to 1,100 m 2 /g.

9. The electrode of claim 1 , wherein the carbon nanotube has an average diameter of 1 nm to 200 nm.

10. The electrode of claim 1 , wherein the carbon nanotube is a multi-walled carbon nanotube.

11. The electrode of claim 1 , wherein the carbon nanotube has an average length of 0.1 μm to 100 μm.

12. A secondary battery comprising:
a positive electrode;
a negative electrode;
a separator disposed between the positive electrode and the negative electrode; and
an electrolyte,
wherein at least one of the positive electrode and the negative electrode is the electrode of claim 1 .

Assignees

• Lg Energy Solution Ltd

Inventors

• Kim Tae Gon
• Park Sin Young
• Lee Bo Ram
• Kim Seul Ki
• Yoo Tae Gu
• Kwak Min

Classifications

• H01M10/052 Primary

  Li-accumulators · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title

• C01B32/184

  Preparation · CPC title

• C01B32/174

  Derivatisation; Solubilisation; Dispersion in solvents · CPC title

• H01M4/625 Primary

  Carbon or graphite · CPC title