Probing Ion Behavior in Porous Carbon Membranes Under Applied Electric Potential Through\textit{ In Situ }SAXS Experiments.

Ion transport and sorption kinetics in soft-templated mesoporous carbon is being studied using small-angle x-ray scattering technique (SAXS). Previous voltage-dependent small-angle neutron scattering (SANS) experiments have shown that this technique can be used to detect structural changes due to ion adsorption at the solid-liquid interface and in the structure of the carbon membranes as the voltage is varied. The average structure of the MC-127 membrane is being determined through the use of SAXS and SASview analysis software. MC-127 has a cylindrical morphology with an average pore-pore distance of 9.4nm. Other properties contribute to its SAXS signal: these include a small spherical shape due to micropores as well as the presence of a second structural correlation at distances larger than the pore-pore distance. To probe ion behavior, a prototype electrochemical cell previously used for SANS is being modified. Efforts are underway to test the cell's performance in a vacuum environment, and the overall electrochemical performance for a given electrode/electrolyte assembly. The current effort will aid the development of better supercapacitors with an optimized electrolyte and electrode geometry combination.