1T-phase transition metal dichalcogenide nanosheets

Patent metadata

Field	Value
Publication number	US-10961127-B2
Application number	US-201816478990-A
Country	US
Kind code	B2
Filing date	Jan 23, 2018
Priority date	Jan 23, 2017
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

A method for the production of 1T-transition metal dichalcogenide few-layer nanosheets and/or monolayer nanosheets comprising electrochemical intercalation of lithium ions into a negative electrode comprising a bulk 2H-transition metal dichalcogenide to provide an intercalated electrode, and an exfoliation step comprising contacting the intercalated electrode with a protic solvent to produce 1T-transition metal dichalcogenide few-layer nanosheets and/or monolayer nanosheets. An electrochemical capacitor comprising a composite electrode comprising 1T-MoS2 nanosheets and graphene, and a method of producing a composite electrode for use in an electrochemical capacitor.

First claim

The invention claimed is:

1. An electrochemical capacitor comprising a composite electrode, the composite electrode comprising 1T-MoS 2 nanosheets and graphene, wherein the 1T-MoS 2 nanosheets is at least 50% by weight trilayer nanosheets and wherein the composite electrode comprises graphene and the MoS 2 nanosheets of the composite electrode are at least 50% 1T phase.

2. The electrochemical capacitor of claim 1 , wherein the composite electrode comprises graphene and MoS 2 nanosheets in a 1:1 weight ratio.

3. The electrochemical capacitor of claim 1 , wherein the composite electrode comprises graphene and MoS 2 nanosheets in a 1:1 weight ratio.

4. A method of producing an electrochemical capacitor of claim 1 , comprising:
producing 1T-transition metal dichalcogenide few-layer nanosheets and/or monolayer nanosheets, the method comprising:
(i) an electrochemical intercalation step in an electrochemical cell, the cell comprising a negative electrode comprising a bulk 2H-transition metal dichalcogenide, a counter electrode which is not lithium, and an electrolyte comprising a lithium salt in a solvent, wherein said solvent is capable of forming a solid electrolyte interface layer;
wherein the electrochemical intercalation step applying a potential difference to the cell so as to intercalate lithium ions into the negative electrode to provide an intercalated electrode; then
(ii) an exfoliation step comprising contacting the intercalated electrode with a protic solvent to produce 1T-transition metal dichalcogenide few-layer nanosheets and/or monolayer nanosheets,
wherein the transition metal dichalcogenide is MoS 2 which produces 1T-MoS 2 nanosheets and the 1T-MoS 2 nanosheets is at least 50% by weight trilayer nanosheets and wherein the MoS 2 nanosheets of the composite electrode are at least 50% 1T phase;

combining the 1T-MoS 2 nanosheets with graphene to produce the composite electrode comprising graphene for use in the electrochemical capacitor; and
producing the electrochemical capacitor comprising the composite electrode comprising graphene.

5. The method of claim 4 , wherein the counter electrode comprises a precious metal.

6. The method of claim 4 , wherein the counter electrode is platinum.

7. The method of claim 4 , wherein the electrolyte comprises a solvent which is selected from dimethyl carbonate, ethylene carbonate, propylene carbonate, and mixtures thereof.

8. The method of claim 4 , wherein the electrolyte is a lithium salt in a mixture of dimethyl carbonate and ethylene carbonate.

9. The method of claim 4 , wherein the lithium salt is LiClO 4 .

10. The method of claim 4 , wherein the potential difference is applied to the electrochemical cell for between 1 and 6 hours.

11. The method of claim 4 , wherein negative electrode is a pellet of compressed 2H-MoS 2 powder.

12. The method of claim 4 , wherein the negative electrode comprises a 2H-MoS 2 crystal.

Assignees

• Univ Manchester

Inventors

• Dryfe Robert
• Ejigu Andinet
• Kinloch Ian

Classifications

• C01P2002/82

  by IR- or Raman-data · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01G11/50

  specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation · CPC title

• C01P2004/24

  Nanoplates, i.e. plate-like particles with a thickness from 1-100 nanometer · CPC title

• H01B1/04

  mainly consisting of carbon-silicon compounds, carbon or silicon · CPC title