scholarly journals Determination of Concentration Gradient and Diffusion Coefficient in Electrolyte of Li-ion Batteries

Author(s):  
Д.А. Ложкина ◽  
А.М. Румянцев ◽  
Е.В. Астрова

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.


2021 ◽  
Vol 894 ◽  
pp. 61-66
Author(s):  
Rui Zhi Dong

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.


Author(s):  
Lei Xu ◽  
Yi Yang ◽  
Ye Xiao ◽  
Wen-Long Cai ◽  
Yu-Xing Yao ◽  
...  
Keyword(s):  

2004 ◽  
Vol 84 (23) ◽  
pp. 4765-4767 ◽  
Author(s):  
S. Blaya ◽  
A. Murciano ◽  
P. Acebal ◽  
L. Carretero ◽  
M. Ulibarrena ◽  
...  

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