THE IMPEDANCE OF LITHIUM ELECTRODES IN LIPF6-BASED ELECTROLYTES

被引：54

作者：

TAKAMI, N ^{[1
]}

OHSAKI, T ^{[1
]}

INADA, K ^{[1
]}

机构：

[1] TOSHIBA BATTERY CORP,SHINAGAWA KU,TOKYO 140,JAPAN

来源：

JOURNAL OF THE ELECTROCHEMICAL SOCIETY | 1992年 / 139卷 / 07期

关键词：

D O I：

10.1149/1.2069510

中图分类号：

O646 [电化学、电解、磁化学];

学科分类号：

081704 ;

摘要：

The impedance spectrum of a lithium electrode in an LiPF6-based electrolyte exhibits one or two semicircles. The variation of the two semicircles with immersion time indicates the presence of two kinds of passivating surface films. The change in resistance (DELTA-R1) associated with the first film during the first 24 h immersion time increased with increasing LiPF6 concentration. The large value of DELTA-R1 in a degraded LiPF6 electrolyte indicated that the decomposition of PF6- would lead to the formation of a thick passivating film. DELTA-R1 was well correlated with the oxidation potential of the solvent, which measures the stability of the solvent against lithium. The change in resistance (DELTA-R2) of the second film over 24 h was smaller than for the first film. The most effective solvent for decreasing DELTA-R1 was an ethylene carbonate (EC)/2-methyl-tetrahydrofuran (2MeTHF) mixed solvent. The lithium cycling efficiency in various solvent systems was demonstrated to increase with a decrease in DELTA-R1. The efficiency of the LiPF6-EC/2MeTHF electrolyte varied significantly with LiPF6 concentration.

引用

页码：1849 / 1854

页数：6

共 15 条

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