Pyrrole Copolymers with Enhanced Ion Diffusion Rates for Lithium Batteries

1997 ◽  
Vol 496 ◽  
Author(s):  
Paul Calvert ◽  
Zack Gardlund ◽  
Trey Huntoon ◽  
H. K. Hall ◽  
Anne Padias
Keyword(s):  
Diffusion Coefficient ◽  
Lithium Batteries ◽  
Fold Increase ◽  
Anion Transport ◽  
Ion Diffusion ◽  
Discharge Characteristics ◽  
Anion Diffusion ◽  
Relaxation Measurements ◽  
Current Densities ◽  
Diffusion Rates

ABSTRACTCopolymers of pyrrole with a polyether-substituted pyrrole were tested as cathodes for lithium batteries. The charge and discharge characteristics showed that anion transport was much faster in the copolymer than in polypyrrole. As a result these electrodes store and release much more charge at higher current densities but are similar to polypyrrole at low currents. Pulse and relaxation measurements of the ion diffusion showed that this difference was due to a ten-fold increase in the anion diffusion coefficient.

Lithium Ion Diffusion Through Glassy Carbon Plate

1997 ◽  
Vol 496 ◽  
Author(s):  
M. Inaba ◽  
S. Nohmi ◽  
A. Funabiki ◽  
T. Abe ◽  
Z. Ogumi
Keyword(s):  
Diffusion Coefficient ◽  
Glassy Carbon ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Irreversible Capacity ◽  
Oxidation Current ◽  
Current Curve ◽  
Carbon Plate ◽  
Lithium Ion Diffusion

ABSTRACTThe electrochemical permeation method was applied to the determination of the diffusion coefficient of Li+ion (DLi+) in a glassy carbon (GC) plate. The cell was composed of two compartments, which were separated by the GC plate. Li+ions were inserted electrochemically from one face, and extracted from the other. The flux of the permeated Li+ions was monitored as an oxidation current at the latter face. The diffusion coefficient was determined by fitting the transient current curve with a theoretical one derived from Fick's law. When the potential was stepped between two potentials in the range of 0 to 0.5 V, transient curves were well fitted with the theoretical one, which gaveDLi+ values on the order of 10−8cm2s−1. In contrast, when the potential was stepped between two potentials across 0.5 V, significant deviation was observed. The deviation indicated the presence of trap sites as well as diffusion sites for Li+ions, the former of which is the origin of the irreversible capacity of GC.

scholarly journals MgFeSiO4 as a potential cathode material for magnesium batteries: ion diffusion rates and voltage trends

2017 ◽  
Vol 5 (25) ◽  
pp. 13161-13167 ◽  
Author(s):  
Jennifer Heath ◽  
Hungru Chen ◽  
M. Saiful Islam
Keyword(s):  
Energy Density ◽  
Cathode Material ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Diffusion Rates ◽  
Magnesium Batteries ◽  
Rechargeable Magnesium Batteries

Developing rechargeable magnesium batteries has become an area of growing interest as an alternative to lithium-ion batteries largely due to their potential to offer increased energy density from the divalent charge of the Mg ion.

Synthesis and Electrochemical Properties of Spherical LiFePO4/C Composite via Spray Drying

2015 ◽  
Vol 1120-1121 ◽  
pp. 554-558 ◽  
Author(s):  
Juan Mei Wang ◽  
Bing Ren ◽  
Ying Lin Yan ◽  
Qing Zhang ◽  
Yan Wang
Keyword(s):  
Diffusion Coefficient ◽  
Electrochemical Properties ◽  
Spray Drying ◽  
Electrochemical Impedance ◽  
Retention Rate ◽  
Lithium Ion ◽  
Constant Current ◽  
Ion Diffusion ◽  
Electrochemical Tests ◽  
Li Ion

In this work, spherical LiFePO4/C composite had been synthesized by co-precipitation and spray drying method. The structure, morphology and electrochemical properties of the samples were characterized by X-ray diffraction (XRD), scanning electron micrograph (SEM), transmission electron microscope (TEM), constant current charge-discharge tests and electrochemical impedance spectroscopy (EIS) tests. The spherical LiFePO4/C particles consisted of a number of smaller grains. The results showed that the morphology of LiFePO4/C particles seriously affected the Li-ion diffusion coefficient and electrochemical properties of lithium ion batteries. Electrochemical tests revealed the spherical LiFePO4/C composite had excellent Li-ion diffusion coefficient which was calculated to be 1.065×10-11 cm2/s and discharge capacity of 149 (0.1 C), 139 (0.2 C), 133 (0.5 C), 129 (1 C) and 124 mAhg-1(2 C). After 50 cycles, the capacity retention rate was still 93.5%.

(Invited) In situ muon spin relaxation for probing ion diffusion in lithium batteries

2021 ◽  
Vol MA2021-01 (7) ◽  
pp. 461-461
Author(s):  
Serena Corr ◽  
Innes McClelland ◽  
Samuel G. Booth ◽  
Hany El-Shinawi ◽  
Beth I.J Johnston ◽  
...  
Keyword(s):  
Spin Relaxation ◽  
Lithium Batteries ◽  
Muon Spin ◽  
Muon Spin Relaxation ◽  
Ion Diffusion

scholarly journals Molecular Modeling to Estimate the Diffusion Coefficients of Drugs and Other Small Molecules

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5340
Author(s):  
Shuichi Miyamoto ◽  
Kazumi Shimono
Keyword(s):  
Diffusion Coefficient ◽  
Molecular Modeling ◽  
Small Molecules ◽  
Einstein Equation ◽  
Diffusion Coefficients ◽  
Small Deviation ◽  
Molecular Transport ◽  
Diffusion Rates ◽  
Van Der Waals Radii ◽  
Potential Use

Diffusion is a spontaneous process and one of the physicochemical phenomena responsible for molecular transport, the rate of which is governed mainly by the diffusion coefficient; however, few coefficients are available because the measurement of diffusion rates is not straightforward. The translational diffusion coefficient is related by the Stokes–Einstein equation to the approximate radius of the diffusing molecule. Therefore, the stable conformations of small molecules were first calculated by molecular modeling. A simple radius rs and an effective radius re were then proposed and estimated using the stable conformers with the van der Waals radii of atoms. The diffusion coefficients were finally calculated with the Stokes–Einstein equation. The results showed that, for the molecules with strong hydration ability, the diffusion coefficients are best given by re and for other compounds, rs provided the best coefficients, with a reasonably small deviation of ~0.3 × 10−6 cm2/s from the experimental data. This demonstrates the effectiveness of the theoretical estimation approach, suggesting that diffusion coefficients have potential use as an additional molecular property in drug screening.

The law of the hydrogen ion diffusion coefficient in acid rock reaction

2016 ◽  
Vol 146 ◽  
pp. 694-701 ◽  
Author(s):  
Qin Li ◽  
Xiangyi Yi ◽  
Yuan Lu ◽  
Gensheng Li ◽  
Wenling Chen
Keyword(s):  
Diffusion Coefficient ◽  
Hydrogen Ion ◽  
Ion Diffusion ◽  
Acid Rock ◽  
The Law

scholarly journals The Steady-State Transport of Oxygen through Hemoglobin Solutions

1966 ◽  
Vol 49 (4) ◽  
pp. 663-679 ◽  
Author(s):  
K. H. Keller ◽  
S. K. Friedlander
Keyword(s):  
Diffusion Coefficient ◽  
Brownian Motion ◽  
Steady State ◽  
Effective Diffusion ◽  
Close Correlation ◽  
Oxygen Electrode ◽  
Low Oxygen ◽  
Diffusion Rates ◽  
Oxygen Tensions ◽  
Diffusion Coefficient Of Oxygen

The steady-state transport of oxygen through hemoglobin solutions was studied to identify the mechanism of the diffusion augmentation observed at low oxygen tensions. A novel technique employing a platinum-silver oxygen electrode was developed to measure the effective diffusion coefficient of oxygen in steady-state transport. The measurements were made over a wider range of hemoglobin and oxygen concentrations than previously reported. Values of the Brownian motion diffusion coefficient of oxygen in hemoglobin solution were obtained as well as measurements of facilitated transport at low oxygen tensions. Transport rates up to ten times greater than ordinary diffusion rates were found. Predictions of oxygen flux were made assuming that the oxyhemoglobin transport coefficient was equal to the Brownian motion diffusivity which was measured in a separate set of experiments. The close correlation between prediction and experiment indicates that the diffusion of oxyhemoglobin is the mechanism by which steady-state oxygen transport is facilitated.

scholarly journals Determination of the Lithium Ion Diffusion Coefficient in Graphite

1999 ◽  
Vol 146 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Ping Yu ◽  
B. N. Popov ◽  
J. A. Ritter ◽  
R. E. White
Keyword(s):  
Diffusion Coefficient ◽  
Lithium Ion ◽  
Ion Diffusion ◽  
Lithium Ion Diffusion
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