title: Importance of Ion Packing on the Dynamics of Ionic Liquids during Micropore Charging.
abstract: Molecular simulations of the diffusion of EMIM(+) and TFSI(-) ions in slit-shaped micropores under conditions similar to those during charging show that in pores that accommodate only a single layer of ions, ions diffuse increasingly faster as the pore becomes charged (with diffusion coefficients even reaching ∼5 × 10(-9) m(2)/s), unless the pore becomes very highly charged. In pores wide enough to fit more than one layer of ions, ion diffusion is slower than in the bulk and changes modestly as the pore becomes charged. Analysis of these results revealed that the fast (or slow) diffusion of ions inside a micropore during charging is correlated most strongly with the dense (or loose) ion packing inside the pore. The molecular details of the ions and the precise width of the pores modify these trends weakly, except when the pore is so narrow that the ion conformation relaxation is strongly constrained by the pore walls.
authors.affiliation: Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Yadong
authors.initials: Y
authors.lastname: He
authors.affiliation: Department of Mechanical Engineering, Virginia Tech , Blacksburg, Virginia 24061, United States.
authors.forename: Rui
authors.initials: R
authors.lastname: Qiao
authors.affiliation: Department of Materials Science & Engineering, University of Utah , Salt Lake City, Utah 84112, United States.
authors.forename: Jenel
authors.initials: J
authors.lastname: Vatamanu
authors.affiliation: Electrochemistry Branch, U.S. Army Research Laboratory , Adelphi, Maryland 20783, United States.
authors.forename: Oleg
authors.initials: O
authors.lastname: Borodin
authors.affiliation: Department of Materials Science & Engineering, University of Utah , Salt Lake City, Utah 84112, United States.
authors.forename: Dmitry
authors.initials: D
authors.lastname: Bedrov
authors.affiliation: Center for Nanophase Materials Sciences and Computer Science & Mathematics Division, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
authors.forename: Jingsong
authors.initials: J
authors.lastname: Huang
authors.affiliation: Center for Nanophase Materials Sciences and Computer Science & Mathematics Division, Oak Ridge National Laboratory , Bethel Valley Road, Oak Ridge, Tennessee 37831, United States.
authors.forename: Bobby G
authors.initials: BG
authors.lastname: Sumpter