Oleg Borodin

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Molecular dynamics (MD) simulations using a many-body polarizable force field were performed on ethylene carbonate (EC) doped with lithium bistrifluoromethanesulfonamide (LiTFSI) salt as a function of temperature and salt concentration. At 313 K Li+ was coordinated by 2.7-3.2 EC carbonyl oxygen atoms and 0.67-1.05 TFSI- oxygen atoms at EC:Li = 10 and 20(More)
Molecular dynamics simulation studies of the structure and the differential capacitance (DC) for the ionic liquid (IL) N-methyl-N-propylpyrrolidinium bis(trifluoromethane)sulfonyl imide ([pyr(13)][TFSI]) near a graphite electrode have been performed as a function temperature and electrode potential. The IL exhibits a multilayer structure that extends 20-30(More)
The liquid-vapor interfacial properties of semifluorinated linear alkane diblock copolymers of the form F(3)C(CF(2))(n-1)(CH(2))(m-1)CH(3) are studied by fully atomistic molecular dynamics simulations. The chemical composition and the conformation of the molecules at the interface are identified and correlated with the interfacial energies. A modified form(More)
Lithium Iodide (LiI) is reported as a promising electrolyte additive for lithium-sulfur batteries. It induces formation of Li-ion-permeable protective coatings on both positive and negative electrodes, which prevent the dissolution of polysulfides on the cathode and reduction of polysulfides on the anode. In addition to enhancing the cell cycle stability,(More)
Quantum chemistry studies of ethylene carbonate (EC) and dimethyl carbonate (DMC) complexes with Li+ and LiPF6 have been conducted. We found that Li+ complexation significantly stabilizes the highly polar cis-trans DMC conformation relative to the nearly nonpolar gas-phase low energy cis-cis conformer. As a consequence, the binding of Li+ to EC in the gas(More)
Lithium-ion batteries raise safety, environmental, and cost concerns, which mostly arise from their nonaqueous electrolytes. The use of aqueous alternatives is limited by their narrow electrochemical stability window (1.23 volts), which sets an intrinsic limit on the practical voltage and energy output. We report a highly concentrated aqueous electrolyte(More)
High throughput screening of solvents and additives with potential applications in lithium batteries is reported. The initial test set is limited to carbonate and phosphate-based compounds and focused on their electrochemical properties. Solvent stability towards first and second reduction and oxidation is reported from density functional theory (DFT)(More)
Classical many-body polarizable force fields were developed for n-alkanes, perflouroalkanes, polyethers, ketones, and linear and cyclic carbonates on the basis of quantum chemistry dimer energies of model compounds and empirical thermodynamic liquid-state properties. The dependence of the electron correlation contribution to the dimer binding energy on(More)
Energy-filtered transmission electron microscopy (EFTEM) was used to determine the distribution of lithium ions in solid polymer electrolytes for lithium batteries. The electrolytes of interest are mixtures of bis(trifluoromethane)sulfonimide lithium salt and symmetric poly(styrene-block-ethylene oxide) copolymers (SEO). In contrast to current solid and(More)
Lithium metal is an ideal battery anode. However, dendrite growth and limited Coulombic efficiency during cycling have prevented its practical application in rechargeable batteries. Herein, we report that the use of highly concentrated electrolytes composed of ether solvents and the lithium bis(fluorosulfonyl)imide salt enables the high-rate cycling of a(More)