Carbon-sulfur complex, method for producing same, and cathode and lithium-sulfur battery comprising same

Patent metadata

Field	Value
Publication number	US-11038194-B2
Application number	US-201816094440-A
Country	US
Kind code	B2
Filing date	Feb 28, 2018
Priority date	Mar 7, 2017
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A carbon-sulfur composite including a carbon aggregate and sulfur, a method for preparing the same, and a positive electrode and a lithium-sulfur battery including the same.

First claim

The invention claimed is:

1. A carbon-sulfur composite comprising:
a carbon aggregate having a hierarchical porosity structure comprised with pores interconnected three-dimensionally and ordered,
wherein the carbon aggregate has a structure in which cylindrical carbon materials are entangled with each other; and
sulfur introduced to at least a part of an external surface and an inside of the carbon aggregate,
wherein the carbon aggregate comprises macropores having a diameter of 300 nm to 800 nm and mesopores having a diameter of 2 nm to 50 nm,
wherein the mesopores and macropores are formed between the cylindrical carbon materials, and
wherein the macropores are formed by removal of template particles, and
wherein the carbon aggregate has an average particle diameter of 1 μm to 500 μm.

2. The carbon-sulfur composite of claim 1 , wherein the cylindrical carbon materials are at least one selected from the group consisting of carbon nanotubes (CNT), graphite nanofibers (GNF), carbon nanofibers (CNF) and activated carbon fibers (ACF).

3. The carbon-sulfur composite of claim 1 , wherein the carbon aggregate has a porosity of 10% to 70%, and a total BET specific surface area of 50 m 2 /g to 1000 m 2 /g.

4. The carbon-sulfur composite of claim 1 , wherein the sulfur includes one or more types selected from the group consisting of elemental sulfur and sulfur series compounds.

5. The carbon-sulfur composite of claim 1 , comprising the carbon aggregate and the sulfur in a weight ratio of 9:1 to 1:9.

6. A method for preparing the carbon-sulfur composite according to claim 1 , comprising:
i) preparing a dispersion in which template particles and the cylindrical carbon materials are mixed;
ii) preparing a template particle-carbon composite by spray drying the dispersion;
iii) preparing the carbon aggregate by heat treating the template particle-carbon composite; and
iv) preparing the carbon-sulfur composite by impregnating sulfur into the carbon aggregate.

7. The method for preparing the carbon-sulfur composite of claim 6 , wherein the template particles are one type selected from the group consisting of polystyrene, polymethyl methacrylate, polyphenyl methacrylate, polyacrylate, poly-alpha-methylstyrene, poly(1-methylcyclohexyl methacrylate), polycyclohexyl methacrylate, polybenzyl methacrylate, polychlorobenzyl methacrylate, poly(1-phenylcyclohexyl methacrylate), poly(1-phenylethyl methacrylate), polyfurfuryl methacrylate, poly(1,2-diphenylethyl methacrylate), polypentabromophenyl methacrylate, polydiphenylmethyl methacrylate, polypentachlorophenyl methacrylate, copolymers thereof and combinations thereof.

8. The method for preparing the carbon-sulfur composite of claim 6 , wherein the template particles have an average particle diameter of 50 nm or greater.

9. The method for preparing the carbon-sulfur composite of claim 6 , wherein a dispersion medium of the dispersion is one or more type selected from the group consisting of water, alcohol, benzene, toluene, pyridine, acetone, tetrahydrofuran (THF) and dimethylformaldehyde (DMF).

10. The method for preparing the carbon-sulfur composite of claim 6 , wherein the spray drying is carried out using a method of spraying at room temperature/atmospheric pressure, pressurized spraying or electrostatic spraying.

11. The method for preparing the carbon-sulfur composite of claim 6 , wherein the heat treatment is carried out at 400° C. to 1200° C.

12. A lithium-sulfur battery comprising:
a positive electrode;
a negative electrode; and
an electrolyte,
wherein the positive electrode includes the carbon-sulfur composite of claim 1 .

13. The carbon-sulfur composite of claim 1 , wherein the carbon aggregate has a total BET specific surface area of 100 m 2 /g to 500 m 2 /g.

14. The carbon-sulfur composite of claim 1 , wherein the carbon aggregate has a total BET specific surface area of 200 m 2 /g to 300 m 2 /g.

Assignees

• Lg Chemical Ltd
• Univ Sogang Res Foundation

Inventors

• Yang Seungbo
• Cho Eunkyung
• Moon Jun Hyuk
• Sohn Kwonnam
• Yang Doo Kyung
• Gueon Donghee

Classifications

• H01M4/1397

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

• H01M4/38

  of elements or alloys · CPC title

• H01M4/5815

  Sulfides · CPC title

• H01M10/052 Primary

  Li-accumulators · CPC title

• H01M4/139

  Processes of manufacture · CPC title