scholarly journals Импедансная спектроскопия пористых кремниевых и кремний-углеродных анодов, полученных спеканием

2020 ◽  
Vol 54 (3) ◽  
pp. 310
Author(s):  
Д.А. Ложкина ◽  
А.М. Румянцев ◽  
Е.В. Астрова
Keyword(s):  
Diffusion Coefficient ◽  
Solid Phase ◽  
Effective Diffusion ◽  
Double Electric Layer ◽  
Electrochemical Process ◽  
Electrical Circuit ◽  
Li Ion Batteries ◽  
Li Ion ◽  
And Diffusion ◽  
Lithium Incorporation

Dry sintered macroporous Si electrodes for Li-ion batteries are first studied using spectral impedance measurements (EIS). The obtained EIS spectra in the lithiated and delithated state are modeled by an equivalent electrical circuit, the parameters of which make it possible to determine the main stages of the electrochemical process of lithium incorporation / extraction caused by the surface layer of solid-state electrolyte (SEI), a double electric layer, and diffusion in the solid phase of the electrode material. It was shown that the effective diffusion coefficient of Li in Si increases with rising degree of lithiation from D = 6.5·10 ^ (-12) cm2/s to D = 2.6·10^ (-10) cm2/s. The effect of carbonization by sucrose pyrolysis was studied, which led to a decrease in impedance and an increase in the diffusion coefficient of lithium to D = 2.2·10^(-10) - 1.7·10^(-9) cm2/s.

Dynamic Modeling of Li-Ion Batteries Using an Equivalent Electrical Circuit

2011 ◽  
Vol 158 (3) ◽  
pp. A326 ◽  
Author(s):  
T. K. Dong ◽  
A. Kirchev ◽  
F. Mattera ◽  
J. Kowal ◽  
Y. Bultel
Keyword(s):  
Dynamic Modeling ◽  
Electrical Circuit ◽  
Equivalent Electrical Circuit ◽  
Li Ion Batteries ◽  
Li Ion

Comparative Studies on VS2 Bilayer and VS2/Graphene Heterostructure as the Anodes of Li Ion Battery

2021 ◽  
Vol 894 ◽  
pp. 61-66
Author(s):  
Rui Zhi Dong
Keyword(s):  
Binding Energy ◽  
Diffusion Barrier ◽  
First Principles ◽  
Electronic Devices ◽  
Lithium Ion ◽  
First Principles Calculations ◽  
Li Ion Batteries ◽  
Capacity Loss ◽  
Li Ion ◽  
And Diffusion

Due to the development of various mobile electronic devices, such as electric vehicles, rechargeable ion batteries are becoming more and more important. However, the current commercial lithium-ion batteries have obvious defects, including poor safety from Li dendrite and flammable electrolyte, quick capacity loss and low charging and discharging rate. It is very important to find a better two-dimensional material as the anode of the battery to recover the disadvantages. In this paper, first principles calculations are used to explore the performances of VS2 bilayer and VS2 / graphene heterostructure as the anodes of Li ion batteries. Based on the calculation of the valences, binding energy, intercalation voltage, charge transfer and diffusion barrier of Li, it is found that the latter can be used as a better anode material from the perspective of insertion voltage and binding energy. At the same time, the former one is better in terms of diffusion barrier. Our study provides a comprehensive understanding on VS2 based 2D anodes.

Li ion Conduction in Cross-Linked Peo-LiCF3SO3 Complex

1988 ◽  
Vol 135 ◽  
Author(s):  
Jun Tsuchiya
Keyword(s):  
Diffusion Coefficient ◽  
Room Temperature ◽  
Transport Number ◽  
Diffusion Measurement ◽  
Poly Ethylene Oxide ◽  
Li Ion ◽  
Poly Ethylene ◽  
Pfg Nmr ◽  
And Diffusion ◽  
Ion Transport Number

AbstractIonic migration of cross-linked amorphous Poly (Ethylene Oxide)-LiCF3SO3was investigated by measuring ionic conductivity and diffusion coefficient. Pulsed-Field-Gradient NMR (PFG-NMR) was used for the diffusion measurement. The measurements were carried out at a temperature region between room temperature and 120°C. The PFG-NMR mea-surement shows the two modes of migration of both cation(Li) and anion (CF3 SO3-) for specimens containing plasticizer (CH30(CHeiH20)gH3C). The two modes of migration for anion are present for specimens without the plasticizer. Li+ transport number is found to be less than 0.1 for specimens without the plasticizer. Plasticizer is found to increase the Li+ ion transport number.

scholarly journals Comparison of Sr Transport in Compacted Homoionous Na and Ca Bentonite Using a Planar Source Method Evaluated at Ideal and Non-Ideal Boundary Condition

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1520
Author(s):  
Lucie Baborová ◽  
Eva Viglašová ◽  
Dušan Vopálka
Keyword(s):  
Diffusion Coefficient ◽  
Surface Diffusion ◽  
Effective Diffusion Coefficient ◽  
Effective Diffusion ◽  
Ideal Boundary ◽  
Batch Sorption ◽  
Compacted Bentonite ◽  
Source Method ◽  
Planar Source ◽  
And Diffusion

With the aim to determine the influence of dominant interlayer cation on the sorption and diffusion properties of bentonite, diffusion experiments with Sr on the compacted homoionous Ca- and Na-forms of Czech natural Mg/Ca bentonite using the planar source method were performed. The bentonite was compacted to 1400 kg·m−3, and diffusion experiments lasted 1, 3 or 5 days. Two methods of apparent diffusion coefficient Da determination based on the analytical solution of diffusion equation for ideal boundary conditions in a linear form were compared and applied. The determined Da value for Ca-bentonite was 1.36 times higher than that for Na-bentonite sample. Values of Kd were determined in independent batch sorption experiments and were extrapolated for the conditions of compacted bentonite. In spite of this treatment, the use of Kd values determined by batch sorption experiments on a loose material for the determination of effective diffusion coefficient De values from planar source diffusion experiments proved to be inconsistent with the standard Fickian description of diffusion taking into account only the pore diffusion in compacted bentonite. Discrepancies between Kd and De values were measured in independent experiments, and those that resulted from the evaluation of planar source diffusion experiments could be well explained by the phenomenon of surface diffusion. The obtained values of surface diffusion coefficients Ds were similar for both studied systems, and the predicted value of total effective diffusion coefficient De(tot) describing Sr transport in the Na-bentonite was four times higher than in the Ca-bentonite.

scholarly journals Association and Diffusion of Li+in Carboxymethylcellulose Solutions for Environmentally Friendly Li-ion Batteries

ChemSusChem ◽  
2016 ◽  
Vol 9 (14) ◽  
pp. 1804-1813 ◽  
Author(s):  
Mosè Casalegno ◽  
Franca Castiglione ◽  
Marco Passarello ◽  
Andrea Mele ◽  
Stefano Passerini ◽  
...  
Keyword(s):  
Environmentally Friendly ◽  
Li Ion Batteries ◽  
Li Ion ◽  
And Diffusion
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