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Thursday, April 25
Zero- to Three-Dimensional Carbon-Based
Yury Gogotsi, Drexel University, Philadelphia, Pennsylvania
Materials for Energy Storage
CNMS Discovery Seminar Series
11:00 AM — 12:00 PM, SNS Central Laboratory and Office Building (8600),
Iran Thomas Auditorium (Room A-103)
Contact: Peter Cummings (firstname.lastname@example.org), 865.241.4779
AbstractThis lecture will provide an overview of research activities in the area of nanostructured carbon and carbide materials used for capacitive storage of electrical energy. Electrochemical capacitors or "supercapacitors" are devices that store electrical energy electrostatically and are used in applications where batteries cannot provide sufficient power or charge/discharge rates, or when a long service life (up to 1 million of cycles) is needed. Until now, their higher cost, compared to batteries, has been limiting the use of supercapacitors in household, automotive and other cost-sensitive applications. We describe the material aspects of supercapacitor development, address unresolved issues and outline future research directions.
High surface area carbon materials are widely used as supercapacitor electrodes. Graphene, nanotubes, activated carbons, template carbons, carbon onions and carbon black are among many materials being used in supercapacitors. Extraction of metals from carbides can generate a broad range of potentially important carbon nanostructures, which range from porous carbon networks to onions and nanotubes. They are known as Carbide-Derived Carbons (CDC). The CDC structure depends on the crystal structure of the carbide precursor as well as process parameters including temperature, time and environment. Extraction of silicon, boron, aluminum, zirconium or titanium from their respective carbides by chlorine at 200-1200°C results in the formation of micro- and mesoporous carbons with the specific surface area up to 3000 m²/g. CDC technology allows the control of carbon growth on the atomic level, monolayer by monolayer, with a high accuracy. It will be shown that the pore size to ion size ratio determines the efficiency of electrochemical energy storage systems. Design of supercapacitor electrodes using nanoporous carbons (3-D), graphene (2-D), carbon nanotubes (1-D) and carbon onions (0-D) for will be addressed. Also, recently discovered 2-D carbides and carbonitrides known as MXenes (Ti3C2, Ti2C and others) will be described.