The mechanism of HF formation in LiPF6 based organic carbonate electrolytes

被引：412

作者：

Lux, S. F. ^{[1
,2
]}

Lucas, I. T. ^{[2
]}

Pollak, E. ^{[2
]}

Passerini, S. ^{[1
]}

Winter, M. ^{[1
]}

Kostecki, R. ^{[2
]}

机构：

[1] Univ Munster, Inst Phys Chem, MEET Labs, D-48149 Munster, Germany

[2] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Environm Energy Technol Div, Berkeley, CA 94720 USA

来源：

ELECTROCHEMISTRY COMMUNICATIONS | 2012年 / 14卷 / 01期

关键词：

Lithium ion batteries; Hydrofluoric acid; Spectroscopic ellipsometry; LiPF6; degradation; ION BATTERY ELECTROLYTES; STABILITY; SALT; CONDUCTIVITY; TEMPERATURE; ELECTRODES; PF5;

D O I：

10.1016/j.elecom.2011.10.026

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

Spectroscopic ellipsometry was used to study the time-dependent formation of HF upon the thermal degradation of LiPF6 at 50 degrees C in a lithium ion battery electrolyte containing ethylene carbonate and diethyl carbonate. The generated HF was monitored by following the etching rate of a 300 nm thick SiO2 layer, grown on both sides of a silicon wafer substrate, as a function of the immersion time in the electrolyte at 50 C degrees. It was found that the formation of HF starts after 70 h of exposure time and occurs following several different phases. The amount of generated HF was calculated using an empirical formula correlating the etching rate to the temperature. Combining the results of the HF formation with literature data, a simplified mechanism for the formation of the HF involving LiPF6 degradation, and a simplified catalytical reaction pathway of the formed HF and silicon dioxide are proposed to describe the kinetics of HF formation. (C) 2011 Elsevier B.V. All rights reserved.

引用

页码：47 / 50

页数：4