Dynamics of Electrochemical Noise of the Lithium Electrode in Aprotic Organic Electrolytes

Abstract

Processes that occur on the lithium electrode under open-circuit conditions and when polarized cathodically and anodically are studied by means of the electrochemical-noise method. The study is carried out in such aprotic organic electrolytes as 1 M solution of LiClO 4 in 1,3-dioxolane; 1 M solution of LiPF 6 in a mixture of ethylene carbonate and diethyl carbonate; and 1 M solution of LiN(CF 3 SO 2 ) 2 in 1,3-dioxolane. An analysis of the noise characteristics of the polarized electrode confirms that the electrochemical process is localized under the passivating film. Potential fluctuations of the electrode polarized at high current densities depend on the electrolyte nature. The amplitude of the electrochemical noise is maximum in the electrolyte system 1 M LiPF 6 in a mixture of ethylene carbonate and diethyl carbonate. The fluctuation intensity is found to correlate with the electrode stability when cycled. This fact suggests that the method can be used for express assessment of organic electrolytes intended for lithium batteries.

The Dependence of Properties of the Electroplated Coatings on the Spectrum of the Variable Components of the Current (Voltage)

“…Thus, if the stationary corrosion transforms into the nonstationary one, i.e., if we have to do with the corrosion localization (the pitting formation), it can be identified by the method of the "noises" record, using certain techniques and special equipment and apparatuses [1]. The above method of electrochemical noises can also be used for the diagnosis of organic electrolytes of accumulators with a metal lithium electrode [5], as well as to determine the degree of a source discharge. V. A. Tyagai found that a slow discharge, fluctuations of reagents in the near-cathode region, the rate of a chemical reaction, photoexitation, intensive gas release (hydrogen, oxygen) on the electrodes, circuit resistance, etc., can be the sources of fluctuations in the electrical circuit rectifier-bath.…”

New methodology of electrochemical noise analysis and applications for commercial Li-ion batteries

“…Noise measurements have been widely used not only in the 1960s in relation to communication systems [7] and semiconductors [8] but also from time to time in electrochemical studies [9][10][11][12]. Electrochemical noise can be caused by different phenomena such as turbulent mass transfer [13][14][15][16][17], gas evolution [18][19][20], electrode corrosion [21][22][23][24] and passivation [25], or water transfer in fuel cells [26].…”