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Title: Li + solvation and kinetics of Li +–BF 4 -/PF 6 - ion pairs in ethylene carbonate. A molecular dynamics study with classical rate theories

Using our polarizable force-field models and employing classical rate theories of chemical reactions, we examine in this paper the ethylene carbonate (EC) exchange process between the first and second solvation shells around Li + and the dissociation kinetics of ion pairs Li +–[BF 4] and Li +–[PF 6] in this solvent. We calculate the exchange rates using transition state theory and correct them with transmission coefficients computed by the reactive flux, Impey, Madden, and McDonald approaches, and Grote-Hynes theory. We found that the residence times of EC around Li + ions varied from 60 to 450 ps, depending on the correction method used. We found that the relaxation times changed significantly from Li +–[BF 4] to Li +–[PF 6] ion pairs in EC. Finally, our results also show that, in addition to affecting the free energy of dissociation in EC, the anion type also significantly influences the dissociation kinetics of ion pairing.
Authors:
ORCiD logo [1] ;  [2]
  1. Univ. of Wisconsin-Parkside, Kenosha, WI (United States). Dept. of Chemistry
  2. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Physical Sciences Division
Publication Date:
Report Number(s):
PNNL-SA-125713
Journal ID: ISSN 0021-9606
Grant/Contract Number:
AC05-76RL01830
Type:
Accepted Manuscript
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 147; Journal Issue: 16; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics (AIP)
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; disperse systems; condensed matter properties; optical metrology; optical properties; thermodynamic properties; computational methods; solvents; chemical solutions; computer simulation; optical constants
OSTI Identifier:
1430712
Alternate Identifier(s):
OSTI ID: 1371791

Chang, Tsun-Mei, and Dang, Liem X. Li+ solvation and kinetics of Li+–BF4-/PF6- ion pairs in ethylene carbonate. A molecular dynamics study with classical rate theories. United States: N. p., Web. doi:10.1063/1.4991565.
Chang, Tsun-Mei, & Dang, Liem X. Li+ solvation and kinetics of Li+–BF4-/PF6- ion pairs in ethylene carbonate. A molecular dynamics study with classical rate theories. United States. doi:10.1063/1.4991565.
Chang, Tsun-Mei, and Dang, Liem X. 2017. "Li+ solvation and kinetics of Li+–BF4-/PF6- ion pairs in ethylene carbonate. A molecular dynamics study with classical rate theories". United States. doi:10.1063/1.4991565. https://www.osti.gov/servlets/purl/1430712.
@article{osti_1430712,
title = {Li+ solvation and kinetics of Li+–BF4-/PF6- ion pairs in ethylene carbonate. A molecular dynamics study with classical rate theories},
author = {Chang, Tsun-Mei and Dang, Liem X.},
abstractNote = {Using our polarizable force-field models and employing classical rate theories of chemical reactions, we examine in this paper the ethylene carbonate (EC) exchange process between the first and second solvation shells around Li+ and the dissociation kinetics of ion pairs Li+–[BF4] and Li+–[PF6] in this solvent. We calculate the exchange rates using transition state theory and correct them with transmission coefficients computed by the reactive flux, Impey, Madden, and McDonald approaches, and Grote-Hynes theory. We found that the residence times of EC around Li+ ions varied from 60 to 450 ps, depending on the correction method used. We found that the relaxation times changed significantly from Li+–[BF4] to Li+–[PF6] ion pairs in EC. Finally, our results also show that, in addition to affecting the free energy of dissociation in EC, the anion type also significantly influences the dissociation kinetics of ion pairing.},
doi = {10.1063/1.4991565},
journal = {Journal of Chemical Physics},
number = 16,
volume = 147,
place = {United States},
year = {2017},
month = {7}
}