介电谱
电极
电解质
相间
阳极
材料科学
电化学
电阻抗
化学物理
分析化学(期刊)
硅
等效电路
化学
电压
光电子学
电气工程
物理化学
生物
遗传学
工程类
色谱法
作者
Etienne Radvanyi,Kristof Van Havenbergh,Willy Porcher,S. Jouanneau,Jean‐Sébastien Bridel,Stijn Put,Sylvain Franger
标识
DOI:10.1016/j.electacta.2014.06.069
摘要
The instability of the Solid Electrolyte Interphase (SEI) at the surface of nano-silicon electrodes has been recognized as one of the key issues to explain the rapid capacity fading of theses electrodes. In this paper, two distinct Si-based systems are studied by using Electrochemical Impedance Spectroscopy (EIS). First, several EIS spectra are recorded along the second electrochemical cycle. Although the active material, the electrode formulation, and the experimental conditions are different for the two systems, the same phenomena are observed in both cases: (i) the SEI deposit around 50 kHz, (ii) the charge transfer (CT) with a characteristic frequency varying from 300 to 1 500 Hz, and (iii) an inductive loop at ∼1 Hz which appears only when the potential of the electrode is below 0.35 V vs Li. As the latter has never been reported for Si-based electrodes, the second step of the work consists in understanding this phenomenon. Thanks to the results obtained in a set of several complementary experiments, we finally attribute the inductive loop to the constant formation/deposition of SEI products, in competition with the CT process. In addition, we propose a mechanism for this specific phenomenon and the equivalent circuit to fit the recorded EIS spectra.
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