Li+ Solvation and Transport Properties in Ionic Liquid/Lithium Salt Mixtures: A Molecular Dynamics Simulation Study

摘要: Molecular dynamics simulations of N-methyl-N-propylpyrrolidinium (pyr(13)) bis(trifluoromethanesulfonyl)imide (Ntf(2)) ionic liquid [pyr(13)][Ntf(2)] mixed with [Li][Ntf(2)] salt have been conducted using a polarizable force field. Mixture lithium mole fractions between 0% and 33% at 363 423 K yield densities, ion self-diffusion coefficients, conductivities in very good agreement available experimental data. In all investigated electrolytes, each Li(+) cation was found to be coordinated, on average, by 4.1 oxygen atoms from surrounding anions. At lower concentrations (x ≤ 0.20), the be, coordinated slightly more than three Ntf(2) anions two contributing single atom one anion coordination. highest concentration, however, there were, 3.5 coordinating cation, corresponding fewer bidendate monodentate coordination sphere. This trend is due increased sharing higher concentrations. [pyr(13)][Ntf(2)]/[Li][Ntf(2)] diffusivity significantly smaller that organic electrolytes not only greater viscosity solvent but also formation clusters resulting cations. The conductivity decrease increasing effect being temperature. Finally, we contribution does increase proportionally concentration saturates doping levels.