Li2S BATTERIES HAVING HIGH CAPACITY, HIGH LOADING, AND HIGH COULOMBIC EFFICIENCY

Patent metadata

Field	Value
Publication number	US-2017179474-A1
Application number	US-201514971676-A
Country	US
Kind code	A1
Filing date	Dec 16, 2015
Priority date	Dec 16, 2015
Publication date	Jun 22, 2017
Grant date	—

Abstract

An electrochemical device includes a cathode containing graphene-wrapped Li 2 S nanoparticles. The graphene-wrapped Li 2 S 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 Li 2 S nanoparticles.

First claim

What is claimed is:

1 . An electrochemical device comprising a cathode comprising graphene-wrapped Li 2 S nanoparticles, wherein the graphene-wrapped Li 2 S nanoparticles are prepared by a method comprising 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 Li 2 S nanoparticles.

2 . The electrochemical device of claim 1 , further comprising an anode and a separator.

3 . The electrochemical device of claim 2 , wherein the anode is a metallic lithium anode.

4 . The electrochemical device of claim 3 , wherein the anode is substantially free of metallic lithium.

5 . A cathode comprising graphene-wrapped Li 2 S nanoparticles, wherein the graphene-wrapped Li 2 S nanoparticles are prepared by a method comprising 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 Li 2 S nanoparticles.

6 . The cathode of claim 5 , further comprising a current collector, a conductive carbon material, a binder, or any combination thereof.

7 . A method of preparing graphene-wrapped Li 2 S nanoparticles comprising 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 Li 2 S nanoparticles.

8 . The method of claim 7 , wherein the temperature is about 180° C. to about 800° C.

9 . The method of claim 7 , wherein the method comprises heating lithium metal and a carbon-sulfur source.

10 . The method of claim 9 , wherein the carbon-sulfur source is CS 2 .

11 . The method of claim 7 , 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 .

12 . The method of claim 7 , wherein the graphene-wrapped Li 2 S nanoparticles comprise Li 2 S nanoparticles encapsulated by graphene nanocages.

13 . The method of claim 12 , wherein the graphene nanocages are about 50 nm to 100 nm wide.

14 . The method of claim 12 , wherein the Li 2 S nanoparticles are uniformly distributed among and within the graphene nanocages.

15 . The method of claim 12 , wherein the graphene nanocages comprise at least 5 graphene layers.

16 . Graphene-wrapped Li 2 S nanoparticles prepared by the method of claim 7 .

Assignees

• Uchicago Argonne Llc

Inventors

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

Classifications

• H01M10/052

  Li-accumulators · CPC title

• Y10S977/735

  Carbon buckyball · CPC title

• H01M4/625

  Carbon or graphite · CPC title

• H01M4/5815

  Sulfides · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title