Nanostructured lithium-ion battery electrode composite materials via conformal graphene dispersion

Patent metadata

Field	Value
Publication number	US-11876168-B2
Application number	US-202117369058-A
Country	US
Kind code	B2
Filing date	Jul 7, 2021
Priority date	Feb 27, 2017
Publication date	Jan 16, 2024
Grant date	Jan 16, 2024

Abstract

Composites comprising anode and cathode active materials conformally coupled to few-layered graphene, corresponding electrodes and related methods of preparation.

First claim

We claim:

1. A method forming a composite for a lithium-ion battery electrode, comprising:
exfoliating a graphene source material with a medium comprising an organic solvent at least partially miscible with water and ethyl cellulose at least partially soluble in said organic solvent to obtain an exfoliated graphene-ethyl cellulose composition containing few-layered graphene comprising mono-, bi- and n-layered graphene, n being an integer selected from 3 to 6, and the ethyl cellulose;
agitating a mixture of nanoparticles of a material selected from lithium-ion cathode active materials for a lithium-ion battery and lithium-ion anode active materials for a lithium-ion battery, and said exfoliated graphene-ethyl cellulose composition in a solvent to disperse said nanoparticles and said few-layered graphene with the ethyl cellulose so as to prevent aggregation of said nanoparticles;
evaporating the solvent from the mixture to form a dispersion of said nanoparticles and said few-layered graphene with the ethyl cellulose; and
ambient annealing the dispersion at a temperature for a period of time to decompose the ethyl cellulose, thereby resulting in said composite,
wherein said few-layered graphene is not graphene oxide and is not reduced graphene oxide.

2. The method of claim 1 , wherein said cathode active material is selected from lithium cobalt oxide, lithium iron phosphate, lithium manganese oxide (LMO), lithium nickel manganese cobalt oxide and lithium nickel cobalt aluminum oxide.

3. The method of claim 2 , wherein said active material is LMO.

4. The method of claim 3 , wherein said nanoparticles comprise a spinel LMO structure.

5. The method of claim 1 , wherein said anode active material is selected from lithium titanate, natural graphite, artificial graphite, activated carbon, carbon black and silicon.

6. The method of claim 1 , wherein the temperature is 285° C., and the period of time is 3 hours.

7. The method of claim 1 , wherein in said composite, said nanoparticles are evenly mixed with said few-layered graphene, and individual said nanoparticles, rather than multi-particle particulates, are conformally coated with a combination of said few-layered graphene and said annealation product of the ethyl cellulose that comprises amorphous carbon with sp 2 -carbon content, such that Raman spectroscopy of said composite has a peak at 2D-band.

8. The method of claim 1 wherein said graphene source material is graphite.

Assignees

• Univ Northwestern

Inventors

• Hersam Mark C
• Chen Kan-Sheng
• Secor Ethan B

Classifications

• H01M10/0525 Primary

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

• H01M4/0416

  involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence) · CPC title

• H01M4/131

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/133

  Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/134

  Electrodes based on metals, Si or alloys · CPC title