Invention Summary:

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 as well as 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.

Background:

Graphene and its closely related graphene oxide nanosheets materials received significant attention due to its many attractive properties, including chemical and electrochemical stability, electrical conductivity and high theoretical surface area. Compared to other carbon allotropes such as carbon nanotube and fullerene, pristine graphene and graphene oxide can be produced by a number of diverse routes ranging from mechanical and chemical exfoliation to chemical vapor deposition. In the current state of research and applications, the production and processing of these nanomaterial have raised concerns about the negative effect of stacking and re-stacking of nanosheets on the properties.   

Market Applications: 

•Supercapacitor/battery electrodes utilizing high accessible surface area graphene oxide granules

•Sorbent oil spills and organic solvent in petroleum industry

•Water desalination utilizing capacitive deionization technology

•Water treatment utilizing granules for adsorption. 

Advantages:

•Scalability: Scale up easily from lab-scale to industrial production

•Performance: Mitigate stacking of graphene nanosheets

•Reliability: Avoid re-stacking during applications

•Safety: Circumvent ESH concerns associated with processing/handling of graphene sheets

Stage of Development or Future Work: Provisional Filed

Keywords:

Graphene, graphene oxide, granules, corrugation

Fig. 1: Spray Drying process to fabricate graphene oxide granules

Fig. 2: Microstructure of graphene oxide granules

Fig. 3:  Graphene oxide granules in supercapacitor electrodes applications