Stable dispersions of single and multiple graphene layers in solution
AssigneeBelenos Clean Power Holdings AG
InventorsReinhard Nesper, Tommy Kaspar
Life of this patent
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Abstract
A method for producing colloidal graphene dispersions comprises the steps of: (i) dispersing graphite oxide in a dispersion medium to form a colloidal graphene oxide or multi-graphene oxide dispersion, and (ii) thermally reducing the graphene oxide or multi-graphene oxide in dispersion. Depending on the method used for the preparation of the starting dispersion, a graphene or a multi-graphene dispersion is obtained that can be further processed to multi-graphene with larger inter-planar distances than graphite. Such dispersions and multi-graphenes are, for example, suitable materials in the manufacturing of rechargeable lithium ion batteries.
Claims27
A method for producing stable colloidal graphene dispersions or stable multi-graphene dispersions, the method comprising the steps of:
- (i) stirring graphite oxide in an aqueous dispersion medium to form a dispersion;
- (ii) determining if the dispersion is optically clear in a light microscope at 1000 fold magnification after 1 to 5 hours of stirring, and, if not clear, removing any undissolved impurities in the dispersion, in order to form a colloidal graphene oxide dispersion, or a multi-graphene oxide dispersion, that is optically clear in a light microscope at 1000 fold magnification;
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- (iii) forming a stable colloidal graphene dispersion or a stable multi-graphene dispersion by thermally reducing the graphene oxide, or the multi-graphene oxide, in dispersion in the aqueous dispersion medium at a temperature between 120° C. and 170° C. under pressure in order to ensure that the dispersion medium is not evaporated.
A method for producing stable colloidal graphene dispersions or stable multi-graphene dispersions, the method comprising the steps of:
- (i) dispersing graphite oxide in an aqueous dispersion medium to form a colloidal graphene oxide dispersion, or to form a multi-graphene oxide dispersion, that is optically clear in a light microscope at 1000 fold magnification;
- (ii) forming a stable colloidal graphene dispersion or a stable multi-graphene dispersion by thermally reducing the graphene oxide, or the multi-graphene oxide, in dispersion in the aqueous dispersion medium at a temperature between 120° C. and 130° C. under pressure in order to ensure that the dispersion medium is not evaporated.
A method for producing stable colloidal graphene dispersions or stable multi-graphene dispersions, the method comprising the steps of:
- (i) stirring not intercalated graphite oxide in an aqueous dispersion medium to form a dispersion;
- (ii) determining if the dispersion is optically clear in a light microscope at 1000 fold magnification after 1 to 5 hours of stirring, and, if not clear, removing any undissolved impurities in the dispersion, in order to form a colloidal graphene oxide dispersion, or a multi-graphene oxide dispersion, that is optically clear in a light microscope at 1000 fold magnification;
- and
- (iii) forming a stable colloidal graphene dispersion or a stable multi-graphene dispersion by thermally reducing the graphene oxide, or the multi-graphene oxide, in dispersion in the aqueous dispersion medium at a temperature between 120° C. and 170° C. under pressure in order to ensure that the dispersion medium is not evaporated.
Dependencies are inferred from the claim text.