Synthesis of Graphene Foam with Controllable Pore Sizes
Opportunity
3D graphene foam shows great promises in energy storage. As an electrode material for energy storage devices like secondary batteries and lithium air batteries, or in hydrogen storage for fuel cells, graphene foam is an attractive option due to its high porosity and electrical conductivity. Growing demand for graphene-based applications across the energy, electronics, automotive, and chemical industries is expected to propel the global graphene market at a CAGR of 43% to reach US$811 million by 2023.
The widespread use of graphene foam, however, is currently hampered by its large pore size and therefore limited surface area. Pore size is a critical parameter in the synthesis of graphene foam as it affects the material’s physiochemical properties but controlling it continues to be a challenge. Reducing pore size and increasing surface area can potentially improve the effectiveness of graphene foam as an electrode material or as a coating for electrodes.
Technology
This invention relates to a novel method of synthesizing 3D structured graphene foam that is very porous (i.e. having a large surface area) and highly crystalline. The resultant graphene foam has a plurality of pore sizes of 5 nm or less. It is a simple and low-cost method with the added benefit of controllable pore sizes and surface areas, and therefore strengthens the feasibility of producing graphene foam on a commercial basis.
The method comprises mixing a carbon source and a skelet powder together to obtain a uniform mixture, applying pressure to the uniform mixture to obtain a closed packed structure, applying temperature and pressure to the closed packed structure to form a graphene sheet layered around the skelet powder and removing the skelet powder from the closed packed structure to obtain the porous 3D crystalline graphene foam. Unlike conventional synthesis methods where material loss, and therefore cost, is significant, this invention offers a simple yet efficient way to synthesise graphene foam.
Process of synthesizing the graphene foam.
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