Online ISSN : 2186-2451
Print ISSN : 1344-3542
ISSN-L : 1344-3542
Transport Properties of Electrolyte Solution Comprising LiPF6, Ethylene Carbonate, and Propylene Carbonate
ジャーナル オープンアクセス

2021 年 89 巻 5 号 p. 439-446


In this study, we experimentally measure the viscosity, η, and ionic conductivity, σ, of 1 mol kg−1 LiPF6 dissolved in a binary solvent of ethylene carbonate (EC) and propylene carbonate (PC) by varying the EC content from 0 to 60 vol%. Replacing EC with PC does not significantly influence on the mechanism of flow and ionic conduction. The state of solvent solvating to Li+ is analyzed using Raman spectra and 13C-NMR; the quantitative analysis suggests that the preference of EC in the Li+ solvation shell is almost similar to that of PC. The diffusion coefficient, D, of each species, Li+, PF6, EC, and PC, is determined by pulse-gradient spin-echo NMR. In the electrolyte system dealt in this study, the molar conductivity is dominated by only the D of the charge carriers. The hydrodynamic Stokes radius of all constituent species is expressed in terms of D and η using the Stokes–Einstein relation. As for coordinated-Li+, a comparison between the Stokes radius and the van der Waals radius or the radius considering the free volume suggests that Li+ diffuses while dragging not only a coordination shell that can be spectroscopically detected but also an outer shell that binds loosely to Li+.

© The Author(s) 2021. Published by ECSJ.

This is an open access article distributed under the terms of the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 License (CC BY-NC-SA, http://creativecommons.org/licenses/by-nc-sa/4.0/), which permits non-commercial reuse, distribution, and reproduction in any medium by share-alike, provided the original work is properly cited. For permission for commercial reuse, please email to the corresponding author. [DOI: 10.5796/electrochemistry.21-00069].
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