Method of preparing and application of carbon-selenium composites

Patent metadata

Field	Value
Publication number	US-11843109-B2
Application number	US-201916426228-A
Country	US
Kind code	B2
Filing date	May 30, 2019
Priority date	Sep 22, 2015
Publication date	Dec 12, 2023
Grant date	Dec 12, 2023

Abstract

The present invention discloses a preparation method to make lithium selenium secondary battery cathode materials with a high energy density and stable electrochemical performances. Two dimensional carbon materials prepared from the presently-disclosed method is not only made from readily-available low-cost raw materials, but is also of simple preparation method. It can effectively shorten the migration distance of lithium ions in the charging and discharging process and improve conductivity and utilization of selenium after compounded with carbon and selenium; the selenium carbon cathode material can be assembled into lithium selenium secondary batteries with high energy density and stable electrochemical performances. By further scaling up, the assembled lithium selenium pouch-cell batteries still hold excellent electrochemical performances and high energy density, showing broad application prospects.

First claim

What is claimed is:

1. A lithium selenium secondary battery, comprising:
a two-dimensional selenium carbon composite material as a cathode material, the two-dimensional selenium carbon composite material prepared by a method comprising:
(a) carbonizing an alkali metal organic salt or an alkaline earth metal organic salt, washing the carbonized salt with an acid, and drying to obtain a two-dimensional carbon nanomaterial; and
(b) mixing the two-dimensional carbon material obtained in step (a) with an organic solvent and selenium, evaporating the organic solvent from the mixture, and then conducting a multistage heat ramping and soaking process to form the two-dimensional selenium carbon composite material;

a lithium-containing anode;
a separator; and
an electrolyte, wherein
the lithium selenium secondary battery has a discharge specific capacity of at least 580 mAh/g and up to 756 mAh/g after 50 cycles of a constant current charge — discharge test with a test voltage range between 1.0 and 3.0 V and a test temperature of 25° C., and
the two-dimensional selenium carbon composite material is free of sulfur.

2. The lithium selenium secondary battery of claim 1 , wherein the lithium-containing anode comprises one or more of lithium metal, a lithiated graphite material, and a lithiated silicon carbon material.

3. The lithium selenium secondary battery of claim 1 , wherein the separator is selected from a Celgard® membrane; a Whatman® membrane; a cellulose membrane; or a polymer membrane.

4. The lithium selenium secondary battery of claim 1 , wherein the electrolyte is one or more of a carbonate electrolyte, an ether electrolyte, and ionic liquids.

5. The lithium selenium secondary battery of claim 4 , wherein the carbonate electrolyte comprises a solvent of one or more of diethyl carbonate ester (DEC), dimethyl carbonate (DMC), ethylene carbonate (EC), ethyl methyl carbonate (EMC), propylene carbonate (PC), and a solute selected from one or more of lithium hexafluoro phosphate (LiPF 6 ), lithium Bis(trifluoromethane)sulfonimide (LiTFSI), lithium perchlorate (LiClO 4 ) and lithium bis(fluorosulfonyl)imide (LiFSI).

6. The lithium selenium secondary battery of claim 4 , wherein the ether electrolyte comprises a solvent of one or more of 1,3-dioxolane (DOL), ethylene glycol dimethyl ether (DME) and triethylene glycol dimethyl ether (TEGDME), and a solute selected from one or more of lithium hexafluorophosphate (LiPF 6 ), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium perchlorate (LiClO 4 ) and lithium bis(fluorosulfonyl)imide (LiFSI).

7. The lithium selenium secondary battery of claim 4 , wherein the ionic liquids comprise one or more of room temperature ionic liquids selected from [EMIm] NTf 2 (1-ethyl-3-methylimidazolium bis trifluoromethane sulfonimide salt), [Py13] NTf 2 (N-Propyl-N-methylpyrrolidine bis trifluoromethane sulfonimide salt), [PP13] NTf 2 (N-propyl-methylpiperidine alkoxy-N-Bis trifluoromethane sulfonimide salts), and a solute selected from one or more of lithium hexafluorophosphate (LiPF 6 ), lithium Bis(trifluoromethane)sulfonimide (LiTFSI), lithium perchlorate (LiClO 4 ) and lithium bis fluorosulfonylimide (LiFSI).

8. The lithium selenium secondary battery of claim 1 , wherein the battery is a pouch-cell battery.

9. The lithium selenium secondary battery of claim 1 , wherein the reduction of the discharge specific capacity between the first cycle and the fiftieth cycle of the constant current charge—discharge test is no more than about 34%.

10. The lithium selenium secondary battery of claim 1 , wherein the battery has a first cycle Coulomb efficiency ranging from 70 to 78.1%.

11. A lithium selenium secondary battery, comprising:
a two-dimensional selenium carbon composite material as a cathode, the two-dimensional selenium carbon composite material prepared by a method comprising:
(a) carbonizing an alkali metal organic salt or an alkaline earth metal organic salt at a temperature≥600° C.;
(b) washing the carbonized salt of step (a) with an acid;
(c) drying the washed carbonized salt of step (b) to obtain a two-dimensional carbon nanomaterial;
(d) mixing the two-dimensional carbon nanomaterial of step (c) with selenium and an organic solvent;
(e) heating the mixture of step (d) to evaporate the organic solvent to form an organic solvent evaporated mixture; and
(f) subjecting the organic solvent evaporated mixture of step (e) to a multistage heat ramping and soaking process to form the two-dimensional selenium carbon composite material;

a lithium-containing anode;
a separator; and
an electrolyte, wherein
the lithium selenium secondary battery has a discharge specific capacity of at least 580 mAh/g and up to 756 mAh/g after 50 cycles of a constant current charge— discharge test with a test voltage range between 1.0 and 3.0 V and a test temperature of 25° C., and
the two-dimensional selenium carbon composite material is free of sulfur.

12. The lithium selenium secondary battery of claim 11 , wherein the lithium-containing anode comprises one or more of lithium metal, a lithiated graphite, and a lithiated silicon carbon.

13. The lithium selenium secondary battery of claim 11 , wherein the separator is a commercial Celgard® membrane, a commercial Whatman® membrane, a cellulose membrane, or a polymer membrane.

14. The lithium selenium secondary battery of claim 11 , wherein the electrolyte is one or more of a carbonate electrolyte, an ether electrolyte, and an ionic liquid.

15. The lithium selenium secondary battery of claim 14 , wherein the carbonate electrolyte comprises a solvent and a solute; the solvent being one or more of diethyl carbonate ester (DEC), dimethyl carbonate (DMC), ethylene carbonate (EC), ethyl methyl carbonate (EMC), and propylene carbonate (PC); and the solute being one or more of lithium hexafluoro phosphate (LiPF 6 ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium perchlorate (LiClO 4 ) and lithium bis(fluorosulfonyl)imide (LiFSI).

16. The lithium selenium secondary battery of claim 14 , wherein the ether electrolyte comprises a solvent and a solute; the solvent being one or more of 1,3-dioxolane (DOL), ethylene glycol dimethyl ether (DME) and triethylene glycol dimethyl ether (TEGDME); and the solute being one or more of lithium hexafluorophosphate (LiPF 6 ), lithium bis (trifluoromethanesulfonyl) imide (LiTFSI), lithium perchlorate (LiClO 4 ) and lithium bis(fluorosulfonyl)imide (LiFSI).

17. The lithium selenium secondary battery of claim 14 , wherein the ionic liquid comprises a room temperature ionic liquid and a solute; the room temperature ionic liquid being one or more [EMIm] NTf 2 (1-ethyl-3-methylimidazolium bis trifluoromethane sulfonimide salt), [Py13] NTf 2 (N-Propyl-N-methylpyrrolidine bis trifluoromethane sulfonimide salt), [PP13] NTf 2 (N-propyl-methylpiperidine alkoxy-N-Bis trifluoromethane sulfonimide salts); and the solute being one or more of lithium hexafluorophosphate (LiPF 6 ), lithium bis(trifluoromethanesufonyl)imide (LiTFSI), lithium perchlorate (LiClO 4 ) and lithium bis (fluorosulfonyl)imide (LiFSI).

18. The lithium selenium secondary battery of claim 11 , wherein the battery is a pouch-cell battery.

19. The lithium selenium secondary battery of claim 11 , wherein the reduction of the discharge specific capacity between the first cycle and the fiftieth cycle of the constant current charge—discharge test is no more than about 34%.

20. The lithium selenium secondary battery of claim 11 , wherein the battery ha

Assignees

• Ii Vi Delaware Inc

Inventors

• Guo Yu-Guo
• Zhang Shuaifeng
• Yin Yaxia

Classifications

• H01M4/134 Primary

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/362 Primary

  Composites · CPC title

• H01M4/38

  of elements or alloys · CPC title

• H01M4/625

  Carbon or graphite · CPC title