1t-phase transition metal dichalcogenide nanosheets

Patent metadata

Field	Value
Publication number	US-2019352190-A1
Application number	US-201816478990-A
Country	US
Kind code	A1
Filing date	Jan 23, 2018
Priority date	Jan 23, 2017
Publication date	Nov 21, 2019
Grant date	—

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 nano sheets 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

1 . A method of 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.

2 . The method of claim 1 , wherein the counter electrode comprises a precious metal.

3 . The method of claim 1 , wherein the counter electrode is platinum.

4 . The method of claim 1 , wherein the electrolyte comprises a solvent which is selected from dimethyl carbonate, ethylene carbonate, propylene carbonate, and mixtures thereof.

5 . The method of claim 1 , wherein the electrolyte is a lithium salt in a mixture of dimethyl carbonate and ethylene carbonate.

6 . The method of claim 1 , wherein the lithium salt is LiClO 4 .

7 . The method of claim 1 , wherein the transition metal dichalcogenide is MoS 2 .

8 . The method of claim 7 , wherein at least 50% by weight of the 1T-transition metal dichalcogenide ‘few-layer nanosheets and/or monosheets’ is trilayer nanosheets.

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

10 . The method of claim 1 , wherein negative electrode is a pellet of compressed 2H-transition metal dichalcogenide powder.

11 . The method of claim 1 , wherein the negative electrode comprises a 2H-transition metal dichalcogenide crystal.

12 . 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.

13 . The electrochemical capacitor of claim 12 , wherein the composite electrode comprises graphene and MoS 2 nanosheets in a 1:1 weight ratio.

14 . A method of producing a composite electrode for use in an electrochemical capacitor, the method comprising combining 1T-MoS 2 nanosheets prepared by a method of claim 1 with graphene.

15 . The electrochemical capacitor of claim 12 , wherein the composite electrode comprises graphene and MoS 2 nanosheets in a 1:1 weight ratio and wherein the MoS 2 nanosheets of the composite electrode are at least 50% 1T phase.

16 . The electrochemical capacitor of claim 12 , wherein the composite electrode comprises graphene and the MoS 2 nanosheets of the composite electrode are at least 50% 1T phase.

17 . A method of producing a composite electrode for use in an electrochemical capacitor, the method comprising combining 1T-MoS 2 nanosheets prepared by a method of claim 8 with graphene.

Assignees

• Univ Manchester

Inventors

• Dryfe Robert
• Ejigu Andinet
• Kinloch Ian

Classifications

• C01P2002/82

  by IR- or Raman-data · CPC title

• H01G11/86

  specially adapted for electrodes (carbonisation or activation of carbon for the manufacture of electrodes H01G11/34) · CPC title

• C01P2002/85

  by XPS, EDX or EDAX data · CPC title

• C01P2006/40

  Electric properties · CPC title

• C01P2002/84

  by UV- or VIS- data · CPC title