Determination of Mass Transfer Parameters and Ionic Association of LiPF6: Organic Carbonates Solutions

被引：57

作者：

Krachkovskiy, Sergey A. ^{[1
]}

Bazak, J. David ^{[1
]}

Fraser, Sean ^{[1
]}

Halalay, Ion C. ^{[2
]}

Goward, Gillian R. ^{[1
]}

机构：

[1] McMaster Univ, Dept Chem, Hamilton, ON L8S 4L8, Canada

[2] Gen Motors Global R&D, Warren, MI 48090 USA

来源：

JOURNAL OF THE ELECTROCHEMICAL SOCIETY | 2017年 / 164卷 / 04期

基金：

加拿大自然科学与工程研究理事会;

关键词：

TRANSPORT PROPERTIES; SPIN ECHOES; DIFFUSION MEASUREMENTS; BATTERY ELECTROLYTES; DIELECTRIC-CONSTANTS; FIELD GRADIENT; SOLVATION; NUMBERS; CONDUCTIVITY; MIXTURES;

D O I：

10.1149/2.1531704jes

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

We report herein on the determination of several mass transport properties (diffusion coefficients for cations, anions, and neutral ionic aggregates; cation transference number) and degree of salt association in electrolyte solutions of practical interest (LiPF6 solutions in binary organic carbonate mixtures), through an analysis of pulsed field gradient NMR and specific conductivity data. Results were obtained as a function of LiPF6 salt concentration in a binary ethylene carbonate (EC) - dimethyl carbonate (DMC) mixture at 1: 1 volume ratios and 30 degrees C, also from 5 degrees C to 35 degrees C for 1 M LiPF6 dissolved in binary mixtures of EC with DMC and EMC at 3: 7, 1: 1 and 7: 3 volume ratios. Li+ transference numbers have significantly lower values than the transport numbers, ranging from 0.31 to 0.35, and display a correct (decreasing) variation with salt concentration, contrary to the trend observed for transport numbers. A remarkably high degree of ion pairing (from 36% to 67%) was observed for the solutions investigated in the present work. (C) 2017 The Electrochemical Society. All rights reserved.

引用

页码：A912 / A916

页数：5

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