Lithium electrochemical systems

To model the characteristics of lithium-sulfur batteries based on the experimental evaluation of the electrochemical properties of electrode materials, the software "Battery Designer", included in the software package “ElChemLab”, was developed. The possibilities of software are described. The specific energy of lithium-sulfur batteries is compared for different surface capacitances of a positive electrode and for different amounts of electrolyte.

The influence of lithium-fluorocarbon glass leads on the stability and preservation, as well as the behavior of differentcurrent leads of insulator is studied. It is shown that the most resistant glass for lithium output is silicon-free glass C62. The behavior of the fluorocarbon cathode current lead (titanium, niobium, molybdenum-rhenium) during storage is investigated. Discovered high corrosion niobium current lead correlation between OCV element and the intensity of corrosion of niobium current lead.

The review of cathode materials for lithium-ion batteries is presented, the analysis of advantages and application prospects of cathode materials on the basis of lithiated transition metals oxides is carried out. A method of heterovalent modification by ions of highly negative elements, lanthanum and its analogues for improving the electrochemical indices and stability of lithium manganese spinel is proposed. The effectiveness of fullerene, lithium fluoride, fullerenes halogen derivatives as modifying additive for MnO₂ cathode materials has been noticed.

DOI: https://doi.org/10.18500/1608-4039-2018-18-3-133-140

DOI: https://doi.org/10.18500/1608-4039-2018-18-3-122-127

Impedance spectroscopy was used to study the initial stages of lithium anode dissolution in SAFT LS-33600 cells at frequencies more than 35 Hz. It was found that experimental results can be described by the dissolution of metals covered by a passive film, including the stages of film dilatation and breakdown of the film.

DOI: https://doi.org/10.18500/1608-4039-2018-18-3-113-121

This article discusses methodical approaches to diagnostics of the state of electrochemical objects including evaluation of the depth of discharge of chemical current sources. Techniques of experiments and software package for data collection and processing are described. The study is focused on identifying the acoustic spectroscopy parameters most closely related to the depth of discharge of chemical current sources.

DOI: https://doi.org/10.18500/1608-4039-2018-18-2-98-108

DOI: https://doi.org/10.18500/1608-4039-2018-18-2-51-76

DOI: https://doi.org/10.18500/1608-4039-2018-18-1-20-25

Low-frequency electrochemical impedance spectroscopy in the frequency range from 12.5 to 5 ⋅ 10⁻⁴ Hz was used to study changes in standard lithium-thionyl chloride cells during their discharge. Analysis of possible equivalent circuits describing the experimental data shows that the behavior of the cells discharged to 70% can be simulated by finite diffusion impedance in this frequency range.

DOI: https://doi.org/10.18500/1608-4039-2018-18-1-13-19

This article discusses the issue of increasing the reliability of evaluation of the depth of discharge of primary chemical sources of electric current by means of acoustic methods, which have never been used for this purpose, and integration of data of acoustic spectroscopy and impedance and noise spectroscopy.