432788 First-Principles-Based Analysis of the Potential Benefits of Graphene Oxide for Supercapacitor Applications

Tuesday, November 10, 2015: 2:35 PM
251F (Salt Palace Convention Center)
Alexander Pak and Gyeong Hwang, McKetta Department of Chemical Engineering, University of Texas at Austin, Austin, TX

In recent years, graphene oxide has been widely-explored as an alternative electrode material for use in supercapacitors.  One of the primary drivers for interest in this material is their ease in solution-based processing, which is highly scalable.  Experimental studies have demonstrated encouraging performance through utilization of these materials, although the observed benefits appear widely scattered and sensitive to the reduction process.  To help clarify the influence of graphene oxide reduction on the interfacial capacitance, we perform combined density functional theory and molecular dynamics simulations to study the influence of oxygen-moiety coverage on graphene at different O:C ratios.  In this talk, we present the sensitivity of the interfacial capacitance to O:C by decoupling the contributions from the quantum and electric double layer capacitances.  In particular, we demonstrate that, under certain conditions, the overall capacitance can be most enhanced when the quantum capacitance effectively mitigates the double layer capacitance.  Our findings clearly demonstrate that graphene oxide is a promising material to consider, in which careful control and optimization of both the concentration and composition of oxygen-containing groups along the basal surface will be required to achieve superior performance in supercapacitors.

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