453434 Non-Coulombic Structure of Ionic Liquid Confined in Carbon Micropores with HR MC-Aided X-Ray Scattering

Tuesday, November 15, 2016: 8:30 AM
Cyril Magnin II (Parc 55 San Francisco)
Katsumi Kaneko1, Ryusuke Futamura1, Taku Iiyama2, Yuma Takasaki3, Mathieu Salanne4, Yury Gogotsi5, Mark Biggs6 and Patrice Simon7,8, (1)Center for Energy and Environmental Science, Shinshu University, Nagano, Japan, (2)Faculty of Science, Shinshu University, Matsumoto, Japan, (3)Faculty of Science, Shinshu University, (4)Sorbonne Universités, (5)Department of Materials Science and Engineering, Drexel University, Philadelphia, PA, (6)Institute for Materials and Processes, Edinburgh, United Kingdom, (7)Université Paul Sabatier, (8)Réseau sur le Stockage Electrochimique de l’Energie


We applied the HRMC simulation-aided X-ray scattering for elucidation of the 3D structure of  ionic liquid of 1-ethyl-3-methylimidazolium bis(trifluorometanesulfonyl) imide (EMI-TFSI) confined in nanopores of carbide-derived carbons of 0.7 nm and 1.0 nm in width. We analyzed the plausible anion-anion, cation-cation, and anion-cation structures using the corresponding electron radial distribution functions obtained from the HRMC. We found the unprecedented accumulation of co-ions in the first coordination shell of EMI-TFSI in the nanopores, although the co-ions in the first coordination shell should be highly repulsive electrostatically. The occupation percents of anions around an anion in 0.7 nm-pores and in bulk liquid are 23 % and 7 %, respectively.  The unusual accumulation of co-ions cannot be understand by Coulomb’s law. The high accumulation of co-ions at the first coordination shell can be ascribed to the creation of image charges in the electrical conductive carbon walls.

Extended Abstract: File Not Uploaded
See more of this Session: Molecular Simulation of Adsorption I
See more of this Group/Topical: Separations Division