ASSESSMENT OF MECHANICAL DAMAGES IN THE PRIMARY Zn-MnO2 BATTERIES BY ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY

Abstract

By current study determined dependence between changing of the average capacitance of the destroyed electrodes of chemical current sources, surface geometry and chemical composition of electrodes surface. In case of the minimum destruction of the surface of the electrode, the maximum value of the average capacity is achieved with the ratio Zn: Mn = 2: 1. The minimum capacity was been at a maximum concentration of manganese on the surface (Zn: Mn = 1: 3) and the maximum degree of destruction. That is, the destruction of the surface of the electrodes leads to a change in the ratio of Zinc and Manganese and with strong surface destruction, the number of Manganese increases significantly. The using of the second frequency-dependent parameter (capacitance dispersion) as a lumped parameter was allowed the application of the principles of electric current commutation for register the layered change in the electric characteristics of the destroyed electrodes. Due to that mathematical technique was obtained a visual picture of the quantitative and qualitative changes on the destroyed surfaces. The general view of the received diagrams repeated the contours of the SEM microphoto images of the same surfaces. There is a presence of sites with the local concentrated deviations from the total distribution of the capacitance in the specific frequency range in case of deep damage in the diagrams. Thus, these diagrams (EIS images) give a clear picture of the electrodes surface of and can be used to evaluate the type of surface damage and the degree of destruction of the electrodes of chemical current sources.

EFFECT OF CONCENTRATION AND NATURE OF LITHIUM SALT ON CHARACTERISTICS OF GEL ELECTROLYTES DMSO-PVDF-LiAn

“…The presence of these extremes, as a rule, is observed in a relatively short period of time, which corresponds to the accepted ideas about the rapid formation of the disordered structure of the SEF [24]. An exception is electrolytes 3, 4, and 8, that is, elec-trolytes based on lithium perchlorate and fluoroborate, where the SEF disorder persists throughout the entire measurement time and may be due to corrosion processes, which is known for solutions with lithium perchlorate in DMSO [28]. With an increase in the contact time of lithium with an electrolyte, the degree of film ordering increases.…”

“…In this case, the graph is presented in the form of a triple diagram of the dependence of the rate of change of capacitance C in a certain time interval ∆t, which is proportional to the capacitance at the beginning of the time interval superimposed on the variation curve of the capacitance as a function of frequency. Taking into account that the dispersion of the capacitance reflects surface disorder arising due to the unevenness of atomic scales and energy inhomogeneities at the electrode -electrolyte interface [25][26][27][28][29], this approach can be Fig.4. EIS images of the changes of the lithium surface in the electrolytes depending on the storage time.…”

Thermo-Galvanic Effects in a Non-Isothermal Element Based on the of Iron-Carbon Compositional Electrode and Alkaline Electrolyte

“…Therefore, it was considered the dependence of the sample capacity distribution and its dispersion in the frequency range 10 1 -10 -1 Hz. The capacity and the dispersion of the capacity were calculated from the impedance spectra according to the technique [20][21][22][23]. By the resulting calculations have been established a correlation between the increasing of OCV, the amount of iron and the increasing of the dispersion of the capacity with a decrease of the measurement's frequency (Fig.…”