FY2010 - Oak Ridge National Laboratory

Seed Money Fund—
Materials Science and Technology Division
Communications article in Physical Review B (82, 020404, 2010) and received the prestigious “Editor’s
Choice” designation. A separate paper on the modeling technique was recently submitted to Physical
Review B. The agreement between the model and the experiment was excellent and allowed us to identify
the complex spin structure that exhibits multiferroic behavior. Thus, we have shown that the excitation
spectrum of a multiferroic material can be used as a dynamical “fingerprint’’ of the spin state. Feng Ye
gave an invited talk about this work during the June 2010 meeting of the American Neutron Scattering
Society in Ottawa.
Information Shared
Haraldsen, J. T., F. Ye, R. S. Fishman, J. A. Fernandez-Baca, Y. Yamaguchi, K. Kimura, and T. Kimura.
2010. “The Multiferroic Phase of Doped CuFeO 2 Identified Using Inelastic Neutron Scattering.”
Phys. Rev. B Rapid Commun. 82, 020404.
05861
High Throughput Synthesis and Chemical Modification of Graphene
Materials for High Capacity Supercapacitors
Nidia C. Gallego, Vinay V. Bhat, and Cristian I. Contescu
Project Description
The goal of this project is to prove the concept that energy storage capacity of graphene-based
supercapacitors can be enhanced via chemical modification. We synthesize graphene materials using a
high throughput chemical method and modify them in a way that would (1) lead to an increase in
electrical double-layer (EDL) capacitance and (2) introduce pseudocapacitance in the material. To
achieve this objective, the graphene materials will be modified by a controlled thermochemical method.
Modified graphenes will have more edge sites, where the amount of energy stored is ~10 times higher
than that on the basal planes. A simple calculation shows a more than 200% increase in the energy storage
capacity for graphenes with 50 vol % holes compared to unmodified ones could potentially be achieved.
The challenge of this task is to chemically modify the surface of graphene materials while maintaining
high surface area and preventing the collapse of the exfoliated structures in dry state. Preparing materials
with high surface area and porosity will ensure adequate electrolyte access to internal surfaces and will
fully use the intrinsic capacitance of graphene materials. Thermochemical treatment will selectively
introduce quinone-type surface groups that will add pseudocapacitance contributions to the total charge
storage.
Mission Relevance
Electrochemical energy storage is one of the key challenges that DOE is addressing in order to harness
renewable energy. EDL capacitors are electrical energy storage devices that bridge the gap between
conventional capacitors and batteries in terms of power and energy density. With their fast
charge/discharge rates and long life cycles, EDL capacitors complement batteries for transportation and
grid applications. The project can help improve the energy storage efficiency of EDL capacitors.
The success of the project will also benefit the Defense Advanced Research Projects Agency. An efficient
EDL capacitor can help to store energy for advanced defense equipment and vehicles that need high
power and fast charging.
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