Graphene-ionic liquid composites

Patent metadata

Field	Value
Publication number	US-2017186561-A1
Application number	US-201615242950-A
Country	US
Kind code	A1
Filing date	Aug 22, 2016
Priority date	Feb 17, 2012
Publication date	Jun 29, 2017
Grant date	—

Abstract

Method of making a graphene-ionic liquid composite. The composite can be used to make electrodes for energy storage devices, such as batteries and supercapacitors.

First claim

1 - 17 . (canceled)

18 . A method of making a graphene-ionic liquid composite:
combining fully exfoliated single sheets of graphite and at least one ionic liquid; coating the combination onto a substrate and heating the combination at a temperature of 200° C. to 450° C.; wherein the at least one ionic liquid comprises 1-ethyl-2-methylimidazolium tetrafluoroborate; and wherein the fully exfoliated single sheets of graphite are approximately ≦1 nm thick;
and have a X-ray diffraction pattern that displays no signature corresponding to graphite or graphite oxide.

19 . The method of claim 18 , wherein the at least one ionic liquid further comprises a member selected from the group consisting of 1-alkyl-3-methylimidazoliumtetrafluoroborates, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF 6 ]), 1-butyl-3-methylimidazolium hydroxide ([bmim]OH), 1-ethyl-3-methylimidazolium dicyanamide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium hexafluorophosphate, trioctylmethylammonium bis(trifluoromethyl-sulfonyl)imide, 1-butyl-3-methylimidazolium chloride, 2-Hydroxyethylammonium formate, 1,3-dialkyl-1,2,3-triazolium hexafluorophosphates, 1,3-dialkyl-1,2,3-triazolium bistriflimides, 1,3-dialkylimidazolium hexafluorophosphates, 1,3-dialkyl-1,2,3-triazolium bistriflimides, triethylsulfonium bis(trifluoromethylsulfonyl)imide, bis(pentafluoroethylsulfonyl)imide, 1-butyl-1-methylpiperidium tetrafluoroborate, choline acetate, 1-butyl-1-methylpiperidinium hexafluorophosphate, 4-ethyl-4-methylmorpholinium methyl carbonate 1-ethyl-1-methylpiperidinium methyl carbonate, triethylsulfonium bis(trifluoromethylsulfonyl)imide, 2-hydroxyethylammonium formate.

20 . The method of claim 18 , wherein the fully exfoliated single sheets of graphite are dispersed in at least one solvent, wherein the at least one solvent comprises an organic solvent.

21 . The method of claim 18 , wherein the fully exfoliated single sheets of graphite are dispersed in at least one solvent and the at least one ionic liquid is present in the composite at 70 wt % or more, based on the total weight of the ionic liquid and graphene source.

22 . The method of claim 18 , wherein the combination is applied to a substrate by a casting method or a printing method, prior to heating.

23 . The method of claim 22 , wherein the substrate is a metal.

24 . The method of claim 22 , wherein the substrate is a current collector.

25 . A method for making an electrode comprising:
combining fully exfoliated single sheets of graphite and at least one ionic liquid; coating the combination onto a substrate and heating the combination at a temperature of 200° C. to 450° C.; wherein the at least one ionic liquid comprises 1-ethyl-2-methylimidazolium tetrafluoroborate; and wherein the fully exfoliated single sheets of graphite are approximately ≦1 nm thick;
and have a X-ray diffraction pattern that displays no signature corresponding to graphite or graphite oxide.

26 . The method of claim 25 , wherein the at least one ionic liquid further comprises a member selected from the group consisting of 1-alkyl-3-methylimidazoliumtetrafluoroborates, 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF 6 ]), 1-butyl-3-methylimidazolium hydroxide ([bmim]OH), 1-ethyl-3-methylimidazolium dicyanamide, 1-butyl-3-methylimidazolium chloride, 1-butyl-3-methylimidazolium hexafluorophosphate, trioctylmethylammonium bis(trifluoromethyl-sulfonyl)imide, 1-butyl-3-methylimidazolium chloride, 2-Hydroxyethylammonium formate, 1,3-dialkyl-1,2,3-triazolium hexafluorophosphates, 3-dialkyl-1,2,3-triazolium bistriflimides, hexafluorophosphates, 1,3-dialkyl-1,2,3-triazolium bistriflimides, triethylsulfonium bis(trifluoromethylsulfonyl)imide, bis(pentafluoroethylsulfonyl)imide, 1-butyl-1-methylpiperidinium tetrafluoroborate, choline acetate, 1-butyl-1-methylpiperidinium hexafluorophosphate, 4-ethyl-4-methylmorpholinium methyl carbonate 1-ethyl-1-methylpiperidinium methyl carbonate, triethylsulfonium bis(trifluoromethylsulfonyl)imide, 2-hydroxyethylammonium formate.

27 . The method of claim 25 , wherein the fully exfoliated single sheets of graphite are dispersed in at least one solvent, wherein the at least one solvent comprises an organic solvent.

28 . The method of claim 25 , wherein the fully exfoliated single sheets of graphite are dispersed in at least one solvent and the at least one ionic liquid is present in the composite at 70 wt % or more, based on the total weight of the ionic liquid and graphene source.

29 . The method of claim 25 , wherein the substrate is a metal.

30 . The method of claim 25 , wherein the substrate is a current collector.

31 . The method of claim 25 , wherein the coating of the combination onto the substrate comprises a casting method and/or a printing method.

32 . The method of claim 28 , wherein the electrode has a specific capacitance of about 140 F/g.

33 . The method of claim 28 , wherein the electrode has an equivalent series resistance of up to 48 Ohms.

34 . The method of claim 18 , wherein the composite comprises no more that about 0.1 wt % solvent after heating.

35 . The method of claim 28 , wherein the combination comprises no more than about 0.1 wt % solvent after heating.

36 . An electrochemical sensor comprising an electrode formed by the method of claim 25 .

Assignees

• Univ Princeton
• Vorbeck Materials Corp

Inventors

• Aksay Ilhan A
• Korkut Sibel
• Pope Michael
• Punckt Christian

Classifications

• C01B2204/22

  Electronic properties · CPC title

• C09D5/24

  Electrically-conducting paints {(conductive materials H01B1/00)} · CPC title

• C01B31/0484

  Chemistry & Metallurgy · mapped topic

• H01M4/364

  as mixtures · CPC title

• C09D11/52

  Electrically conductive inks · CPC title