Chemical diffusion coefficient of lithium ion in Li3V2(PO4)3 cathode material

2009 ◽  
Vol 63 (27) ◽  
pp. 2396-2398 ◽  
Author(s):  
Anping Tang ◽  
Xianyou Wang ◽  
Guorong Xu ◽  
Ronghua Peng ◽  
Huidong Nie
Keyword(s):  
Diffusion Coefficient ◽  
Cathode Material ◽  
Lithium Ion ◽  
Chemical Diffusion ◽  
Chemical Diffusion Coefficient

Synthesis and Characterization of LiVOPO4 Cathode Material by Solid-State Method

2012 ◽  
Vol 554-556 ◽  
pp. 436-439 ◽  
Author(s):  
An Ping Tang ◽  
Ze Qiang He ◽  
Jie Shen ◽  
Guo Rong Xu
Keyword(s):  
Solid State ◽  
Cathode Material ◽  
Lithium Ion ◽  
Chemical Diffusion ◽  
Chemical Diffusion Coefficient ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Solid State Method ◽  
X Ray ◽  
State Method

Lithium vanadyl phosphate (β-LiVOPO4) cathode material for lithium ion batteries was prepared via a novel solid state method. The microstructure and electrochemical properties of the sample were characterized by X-ray diffraction, scanning electron microscopy, galvanostatically discharge/discharge and cyclic voltammetry techniques, respectively. X-ray diffraction patterns showed that β-LiVOPO4 has an orthorhombic structure with space group of Pnma. The discharge capacity of LiVOPO4 sample is 89.9 mAh•g-1 in the first cycle, and in the 50th cycle it is 76.2 mAh•g-1 at the current density of 10 mA•g-1 between 3.0-4.5 V. The chemical diffusion coefficient ( ) value determined from CV is about 10-11 cm2 s-1. Experimental results indicate that further efforts are needed to improve electrochemical performances of LiVOPO4 material synthesized by solid state method; however, it has a higher discharge plateau around 3.9 V.

scholarly journals Femtosecond Laser Processing of Thick Film Cathodes and Its Impact on Lithium-Ion Diffusion Kinetics

2019 ◽  
Vol 9 (17) ◽  
pp. 3588 ◽  
Author(s):  
Wilhelm Pfleging ◽  
Petronela Gotcu
Keyword(s):  
Diffusion Coefficient ◽  
Thick Film ◽  
Active Material ◽  
Lithium Ion ◽  
Chemical Diffusion ◽  
Chemical Diffusion Coefficient ◽  
Ion Diffusion ◽  
Femtosecond Laser Processing ◽  
Specific Discharge ◽  
Li Ion

Quantitative experiments of lithiation/delithiation rates were considered for a better understanding of electrochemical intercalation/deintercalation processes in laser structured thick film cathodes. Besides galvanostatic cycling for evaluation of specific discharge capacities, a suitable quantitative approach for determining the rate of Li-ion insertion in the active material and the rate of Li-ion transport in the electrolyte is expressed by chemical diffusion coefficient values. For this purpose, the galvanostatic intermittent titration technique has been involved. It could be shown that laser structured electrodes provide an enhanced chemical diffusion coefficient and an improved capacity retention at high charging and discharging rates.

scholarly journals Boundary layer analysis for a 2-D Keller-Segel model

2020 ◽  
Vol 18 (1) ◽  
pp. 1895-1914
Author(s):  
Linlin Meng ◽  
Wen-Qing Xu ◽  
Shu Wang
Keyword(s):  
Boundary Layer ◽  
Diffusion Coefficient ◽  
Approximate Solution ◽  
Chemical Diffusion ◽  
Singular Perturbation Theory ◽  
Energy Estimates ◽  
Chemical Diffusion Coefficient ◽  
Boundary Layer Problem ◽  
Classical Energy ◽  
Layer Analysis

Abstract We study the boundary layer problem of a Keller-Segel model in a domain of two space dimensions with vanishing chemical diffusion coefficient. By using the method of matched asymptotic expansions of singular perturbation theory, we construct an accurate approximate solution which incorporates the effects of boundary layers and then use the classical energy estimates to prove the structural stability of the approximate solution as the chemical diffusion coefficient tends to zero.

Diffusion und Korrelation in goldreichen Gold—Zinn-Mischkristallen / Diffusion and Correlation in Gold-Rich Gold—Tin Solid Solutions

1972 ◽  
Vol 27 (7) ◽  
pp. 1109-1118 ◽  
Author(s):  
Chr. Herzig ◽  
Th. Heumann
Keyword(s):  
Diffusion Coefficient ◽  
Impurity Content ◽  
Chemical Diffusion ◽  
Correlation Factor ◽  
Coarse Grained ◽  
Pure Gold ◽  
Large Temperature ◽  
Chemical Diffusion Coefficient ◽  
Self Diffusion ◽  
Different Temperatures

Abstract The diffusion of Sn-113 and Au-195 in pure gold and dilute tin -gold alloys has been measured at different temperatures and tin concentrations in coarse-grained specimens. In addition the dependence on concentration of the chemical diffusion coefficient and the diffusion of tin in gold at very low impurity concentrations has been determined using the electron microprobe. It was found, that the self-diffusion coefficient of tin as well as that of gold increased strongly with in-creasing impurity content. The thermodynamic factor is equal to one up to ca. 0.5 at.-% tin. For the correlation factor of the diffusion of tin in gold, calculated by the relation of Lidiard, an essentially temperature independent value is obtained. A comparison of the experimental results with the model of Le Claire concerning the impurity diffusion in metals shows, that this model seems to require a too-large temperature dependence of the correlation factor

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