January 1, 2015.
Supercapacitors, otherwise known as electrical double layer capacitors, are a new type of electrochemical capacitor whose storage capacity is governed by two principals: the electrostatic storage achieved by a separation of charge at the interface of an electrode with an electrolytic solution, and pseudocapacitance, whose electrical energy is achieved by faradaic redox reactions. This project reports the synthesis and characterization of vertically-oriented graphene grown on copper substrates as electrodes in electric double-layer capacitor. Graphene is a two-dimensional pure carbon material with a high potential for energy storage. With vertically-grown graphene, an exponentially-larger surface area is made available, allowing an increase in electrostatic storage. Nano-sheets of carbon were fabricated via plasma-enhanced chemical vapor deposition and characterized using cyclic voltammetry and Raman spectrometry. Specific capacitance was compared using with both aqueous and organic electrolytes, as well as variations with growth conditions and scan rates. Applications of the supercapacitor range from energy storage in space exploration to consumer electronics and transportation.
Michael M. Oye
NASA Ames Research Center (ARC)
This material is based upon work supported by the S.D. Bechtel Jr. Foundation and is made possible with contributions from the National Science Foundation under Grant No. 1340110, Howard Hughes Medical Institute, Chevron Corporation, National Marine Sanctuary Foundation, and from the host research center. Any opinions, findings, and conclusions or recommendations expressed in this material are solely those of the authors. The STAR Program is administered by the Cal Poly Center for Excellence in STEM Education on behalf of the California State University system.