Environmentally benign production of graphene materials
AssigneeAngstron Materials
InventorsAruna Zhamu, Bor Z. Jang
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Abstract
An intercalated graphite compound composition, comprising a layered graphite with interlayer spaces or interstices and an intercalant residing in at least one of said interstices, wherein said intercalant comprises a carboxylic acid and an oxidant selected from Li2FeO4, Na2FeO4, K2FeO4, LixCoO4, NaxCoO4, KxCoO4, LixNiO4, NaxNiO4, KxNiO4, or a combination thereof. This compound can be produced in an environmentally benign process. The compound can be further treated to produce separate graphene sheets.
Claims20
An intercalated graphite compound for the production of exfoliated graphite, flexible graphite, or nano graphene platelets, said compound comprising a layered graphite with interlayer spaces or interstices and an intercalant or its component ions residing in at least one of said interstices, wherein said intercalant is sulfuric acid-free and comprises a carboxylic acid and an oxidant selected from Li2FeO4, Na2FeO4, K2FeO4, LixCoO4, NaxCoO4, KxCoO4, LixNiO4, NaxNiO4, KxNiO4, or a combination thereof, where x is from 1 to 2.
An intercalated graphite compound for the production of exfoliated graphite, flexible graphite, or nano graphene platelets, said compound comprising a layered graphite with interlayer spaces or interstices and an intercalant residing in at least one of said interstices, wherein said intercalant comprises sulfuric acid, and an oxidant selected from Li2FeO4, Na2FeO4, LixCoO4, NaxCoO4, KxCoO4, LixNiO4, NaxNiO4, KxNiO4, a combination thereof, or a combination with K2FeO4, where x is from 1 to 2, and said layered graphite material is selected from synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, graphitic nano-fiber, graphite oxide, graphite fluoride, chemically modified graphite, exfoliated graphite, expanded graphite, or a combination thereof.
A method of producing exfoliated graphite or separate sheets of a graphene material from an intercalated graphite compound, said method comprising:
- a) preparing said intercalated graphite compound from a layered graphite material using an electrochemical reaction process which uses an intercalant as both an electrolyte and an intercalate source, wherein said layered graphite material is selected from natural graphite, synthetic graphite, highly oriented pyrolytic graphite, graphite fiber, graphitic nano-fiber, graphite oxide, graphite fluoride, chemically modified graphite, exfoliated graphite, expanded graphite, or a combination thereof, and said intercalant contains an acid and an oxidant selected from Li2FeO4, Na2FeO4, K2FeO4, LixCoO4, NaxCoO4, KxCoO4, LixNiO4, NaxNiO4, KxNiO4, or a combination thereof;
- b) bringing said intercalated graphite compound into a dry powder form or a suspension containing said intercalated graphite compound dispersed in a fluid;
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- c) subjecting said suspension to an ultrasonication or mechanical shearing treatment with a desired sonication or shearing intensity for a length of time sufficient for producing said separate sheets of graphene, or exposing said dry intercalated graphite compound powder to a heat treatment at a temperature from 100° C. to 1,500° C. to produce said exfoliated graphite or, directly, said separate sheets of graphene.
Dependencies are inferred from the claim text.