Li2S batteries having high capacity, high loading, and high coulombic efficiency

Patent metadata

Field	Value
Publication number	US-10170756-B2
Application number	US-201514971676-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Dec 16, 2015
Publication date	Jan 1, 2019
Grant date	Jan 1, 2019

Abstract

An electrochemical device includes a cathode containing graphene-wrapped Li2S nanoparticles. The graphene-wrapped Li2S nanoparticles are prepared by a method including heating lithium metal, and a carbon-sulfur source or a carbon source and a sulfur source in a sealed container at a temperature to produce lithium vapors, and vapors of the carbon-sulfur source or vapors of the carbon source and vapors of the sulfur source; and cooling the sealed container to produce the graphene-wrapped Li2S nanoparticles.

First claim

What is claimed is:

1. A method of preparing graphene-wrapped Li 2 S nanoparticles, the method comprising:
heating lithium metal and a carbon-sulfur source or lithium metal, a carbon source, and a sulfur source in a sealed container at a temperature to produce lithium vapors and vapors of the carbon-sulfur source, or lithium vapors, vapors of the carbon source, and vapors of the sulfur source; and
cooling the sealed container to produce the graphene-wrapped Li 2 S nanoparticles.

2. The method of claim 1 , wherein the temperature is about 180° C. to about 800° C.

3. The method of claim 1 , wherein the method comprises heating lithium metal and a carbon-sulfur source.

4. The method of claim 3 , wherein the carbon-sulfur source is CS 2 .

5. The method of claim 1 , wherein the graphene-wrapped Li 2 S nanoparticles have a Li 2 S loading of about 1 mg/cm 2 to about 15 mg/cm 2 .

6. The method of claim 1 , wherein the graphene-wrapped Li 2 S nanoparticles comprise Li 2 S nanoparticles encapsulated by graphene nanocages.

7. The method of claim 6 , wherein the graphene nanocages are about 50 nm to 100 nm wide.

8. The method of claim 6 , wherein the Li 2 S nanoparticles are uniformly distributed among and within the graphene nanocages.

9. The method of claim 6 , wherein the graphene nanocages comprise at least 5 graphene layers.

10. Graphene-wrapped Li 2 S nanoparticles prepared by the method of claim 1 .

11. A cathode comprising the graphene-wrapped Li 2 S nanoparticles of claim 10 .

12. The cathode of claim 11 , further comprising a current collector, a conductive carbon material, a binder, or any combination thereof.

Assignees

• Uchicago Argonne Llc

Inventors

• Lu Jun
• Xu Rui
• Amine Khalil
• Ji Xiulei

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• Y10S977/842

  for carbon nanotubes or fullerenes · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• Y10S977/735

  Carbon buckyball · CPC title