Negative electrode active material for rechargeable battery, method for producing the same, and rechargeable battery

Patent metadata

Field	Value
Publication number	US-12537191-B2
Application number	US-201917275022-A
Country	US
Kind code	B2
Filing date	Nov 22, 2019
Priority date	Nov 22, 2018
Publication date	Jan 27, 2026
Grant date	Jan 27, 2026

Abstract

A negative electrode active material for a rechargeable battery of the present invention includes a silicon composite composed of a silicon compound and at least one carbon material of graphite, non-graphitizable carbon, and soft carbon, a self-assembled monolayer which covers the surface of the silicon composite and has amino groups, and a carbon compound that is bonded to the self-assembled monolayer via the amino groups and contains carbon atoms as a main component.

First claim

The invention claimed is:

1 . A negative electrode active material for a rechargeable battery, comprising:
a silicon composite composed of a silicon compound and at least one carbon material of graphite, non-graphitizable carbon, and soft carbon; a self-assembled monolayer which covers the surface of the silicon composite and has amino groups; and a carbon compound that is bonded to the self-assembled monolayer via the amino groups and contains carbon atoms as a main component, wherein the carbon compound is a carbon nanotube, positively charged functional groups (—NH 3 + ) among amino groups formed on the self-assembled monolayer and carboxylic groups formed on the carbon nanotube are non-covalently bonded by an attractive force associated with an electrostatic interaction, the silicon composite has an amide bond with carboxylic groups of the carbon nanotubes, a plurality of the silicon composites are connected by the carbon nanotubes, and when waveforms of X-ray Photoelectron Spectroscopy (XPS) spectrums for each binding energy are separated, a first relative area ratio of a spectrum for the silicon composite having a non-covalent bond is larger than a second relative area ratio of a spectrum for the silicon composite having an amide bond.

2 . The negative electrode active material for a rechargeable battery according to claim 1 ,
wherein the silicon compound occupies 5% or more of the volume of the silicon composite.

3 . The negative electrode active material for a rechargeable battery according to claim 1 ,
wherein at least one of Si, SiO, and SiOx (x is a positive real number) is contained as the silicon compound in the silicon composite.

4 . A rechargeable battery comprising the negative electrode active material according to claim 1 .

5 . A method for producing the negative electrode active material for a rechargeable battery according to claim 1 , the method comprising:
a process of forming the carbon compound having the carboxylic groups; a process of forming the silicon composite having the amino groups; and a process of mixing the carbon compound and the silicon composite in a liquid and bonding the carboxylic groups and the amino groups.

6 . The method for producing the negative electrode active material for a rechargeable battery according to claim 5 ,
wherein a condensing agent is added to the liquid.

7 . The method for producing the negative electrode active material for a rechargeable battery according to claim 6 ,
wherein 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride is used as the condensing agent.

8 . The negative electrode active material for a rechargeable battery according to claim 1 ,
wherein the first relative area ratio is more than 43.7/20.2 times as large as the second relative area ratio.

Assignees

• Univ Shinshu
• Meijo Nano Carbon Co Ltd

Inventors

• Zettsu Nobuyuki
• Teshima Katsuya
• Kim Hyemin

Classifications

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/386 Primary

  Silicon or alloys based on silicon · CPC title

• C01B32/168

  After-treatment · CPC title

• H01M4/625

  Carbon or graphite · CPC title