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

Patent metadata

Field	Value
Publication number	US-11088392-B2
Application number	US-201815906776-A
Country	US
Kind code	B2
Filing date	Feb 27, 2018
Priority date	Feb 27, 2017
Publication date	Aug 10, 2021
Grant date	Aug 10, 2021

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 composite, comprising:
few-layered graphene, comprising mono-, bi- and n-layered graphene, wherein n is an integer selected from 3 to 6;
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
an annealation product of an ethyl cellulose;
wherein said composite is formed by
agitating a mixture of said nanoparticles, said few-layered graphene and the ethyl cellulose 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 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 the 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; and
wherein said few-layered graphene is not graphene oxide and is not reduced graphene oxide.

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

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

5. The composite 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 composite of claim 3 , wherein the packing density of said LMO is 2.1 g cm −3 .

7. The composite of claim 1 , wherein a cathode comprising said nanoparticle/graphene composite has a volumetric energy density between 800 and 1200 Wh L −1 at 0.2C current rate.

8. The composite of claim 7 , wherein said cathode comprising said nanoparticle/graphene composite has a volumetric energy density of 1030 Wh L −1 at 0.2C current rate.

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

10. The composite of claim 1 , wherein the mixture contains 66.7 wt. %, 7.3 wt. %, and 26 wt. % of said nanoparticles, said few-layered graphene, and ethyl cellulose, respectively.

11. The composite of claim 3 , wherein said LMO is at least 80 wt. % of said composite.

Assignees

• Univ Northwestern

Inventors

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

Classifications

• H01M4/133

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

• H01M4/131

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

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/136

  Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy · CPC title

• H01M4/139

  Processes of manufacture · CPC title