Method of making a composition comprising graphene sheets and at least one solvent, comprising dispersing a mixture of graphene sheets and graphite particles in a solvent, wherein the graphite particles have more than about 50 layers, separating the graphene sheets and the graphite particles to obtain a dispersion of graphene sheets that contains no more than 25% of graphite particles having more than about 50 layers, based on the total number of graphite particles and graphene sheets, and flocculating the dispersion of graphene sheets. The flocculated dispersion can be added to a polymer matrix to make a composite. The composite can be formed into articles.
Embodiments of the present invention relate to energy storage devices and associated methods of manufacture. In one embodiment, an energy storage device comprises an electrolyte. An anode is at least partially exposed to the electrolyte. A selectively permeable membrane comprising a graphene-based material is positioned proximate to the anode. The selectively permeable membrane reduces a quantity of a component that is included in the electrolyte from contacting the anode and thereby reduces degradation of the anode.
The present invention relates to conducting elastomers and assocd. fabrication methods. In one embodiment, the conducting elastomer comprises a filler powder and a polymer. The filler powder includes carbon black and functionalized graphene sheets. The polymer has a mol. wt. of about 200 g/mol to about 5000 g/mol and is a liquid at room temperature.
Embodiments of the present invention relate to battery electrodes incorporating composites of graphene and selenium-sulfur compds. for improved rechargeable batteries. In one embodiment, a conductive compn. comprises a conductive compn. having a Se-S compd., a conductive additive. The Se-S compd. is present as SexS8-x, wherein x is greater than zero and less than eight.
A method for the electrohydrodynamic deposition of carbonaceous materials utilizing an electrohydrodynamic cell comprising two electrodes comprised of a conductive material, by first combining a solid phase comprising a carbonaceous material and a suspension medium, placing the suspension between the electrodes, applying an electric field in a first direction, varying the intensity of the electric field sufficiently to drive lateral movement, increasing the electric field to stop the lateral transport and fix the layers in place, then removing the applied field and removing the electrodes. Among the many different possibilities contemplated, the method may advantageously utilize: varying the spacing between the electrodes; removing the buildup from one or both electrodes; placing the electrodes into different suspensions; adjusting the concentration, pH, or temperature of the suspension(s); and varying the direction, intensity or duration of the electric fields.