Granules of graphene oxide by spray drying

Abstract

Granules of graphene oxide may be produced from a dispersion of nanoscale graphene oxide sheets by a spray drying method. Such granules have a three-dimensional corrugated morphology. The complexity of the corrugations, and the size distribution of the granules can be varied through selection of the spray-drying equipment used, and variation of the composition of the dispersion and the spray-drying parameters. Structural modifiers may be included in the graphene oxide dispersion to control the ultimate morphology of the granules. The granules of graphene oxide may be thermally reduced at a moderate temperature of 220° C. to increase the granules' electrical conductivity. The reduced granules may be used to fabricate electrodes for supercapacitors. The power and energy density of such an electrode material is comparable to those of conventional / commercial activated carbon-based electrodes.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present application claims the benefit of U.S. Provisional Patent Application No. 61 / 754,223, filed on Jan. 18, 2013, the disclosure of which is incorporated by reference herein.FIELD OF THE INVENTION[0002]The present invention relates to granules of graphene oxide and methods of making same, and, more specifically, to granules of graphene oxide useful for fabricating electrical components.BACKGROUND OF THE INVENTION[0003]Graphene has recently received significant attention due to its many attractive properties, including: chemical and electrochemical stability; electrical conductivity; and high theoretical surface area (e.g., 2630 m2 / g). This theoretical surface area compares well to those of: carbon nanotubes (CNT) (e.g., 1315 m2 / g); and is commercially available activated carbon (typically, 500 m2 / g). A common method of producing CNT is chemical vapor deposition (CVD), which has remained quite expensive despite several decades of r...

AI Technical Summary

Benefits of technology

The present invention relates to granules containing corrugated graphene nanosheets that have significantly greater surface area and longer ion pathways compared to non-corrugated granules of similar size. These granules can also have a structural modifier that enhances the corrugations. The granules can contain reduced graphene oxide and are useful in making electrodes for capacitors. These technical effects improve the performance and efficiency of the resulting devices.

Problems solved by technology

In some embodiments, the granules include a structural modifier that modifies the morphology of the granules, and increases the degree and complexity of the corrugations.

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