scholarly journals Galvanostatic Intermittent Titration Technique Reinvented: Part II. Experiments

2021 ◽  
Vol 168 (12) ◽  
pp. 120503 ◽  
Author(s):  
Stephen Dongmin Kang ◽  
Jimmy Jiahong Kuo ◽  
Nidhi Kapate ◽  
Jihyun Hong ◽  
Joonsuk Park ◽  
...  
Keyword(s):  
Particle Surface ◽  
Chemical Diffusion ◽  
Total Conductivity ◽  
Diffusion Measurement ◽  
Chemical Diffusivity ◽  
Modified Method ◽  
Titration Procedure ◽  
Galvanostatic Intermittent Titration Technique ◽  
Li Ion ◽  
Titration Technique

Following a critical review of the galvanostatic intermittent titration technique in Part I, here we experimentally demonstrate how to extract chemical diffusivity with a modified method. We prepare dense bulk samples that ensure diffusion-limitation. We utilize the scaling with t relax + τ − t relax (t relax: relaxation time; τ: pulse duration), avoiding problems with composition-dependent overpotentials. The equilibrium Nernst voltage is measured separately using small porous particles. This separation between the diffusion measurement and the titration procedure is critical for performing each measurement in a reliable setting. We report the chemical diffusion coefficients of LixNi1/3Mn1/3Co1/3O2 and their activation energy. We extract ionic conductivity and compare it with total conductivity to confirm ion-limitation in chemical diffusion. The measurements suggest that the time scale for diffusion in typical Li-ion battery particles could be much shorter than that of the intercalation/deintercalation processes at the particle surface (Biot number less than 0.1).

Li-ion diffusion behavior in Sn, SnO and SnO2 thin films studied by galvanostatic intermittent titration technique

2010 ◽  
Vol 181 (35-36) ◽  
pp. 1611-1615 ◽  
Author(s):  
J. Xie ◽  
N. Imanishi ◽  
A. Hirano ◽  
Y. Takeda ◽  
O. Yamamoto ◽  
...  
Keyword(s):  
Thin Films ◽  
Ion Diffusion ◽  
Diffusion Behavior ◽  
Galvanostatic Intermittent Titration Technique ◽  
Li Ion ◽  
Sno2 Thin Films ◽  
Titration Technique

A Basic Thin Film Study of Spinel Limn204As a Possible Cathode Material for Lithium Secondary Cells

1995 ◽  
Vol 393 ◽  
Author(s):  
Takashi Miura ◽  
Tomiya Kishi
Keyword(s):  
Single Phase ◽  
Chemical Diffusion ◽  
Phase Region ◽  
Chemical Diffusion Coefficient ◽  
Galvanostatic Charge ◽  
Active Materials ◽  
Film Study ◽  
Galvanostatic Intermittent Titration Technique ◽  
Titration Technique ◽  
Charge Discharge

ABSTRACTIn a series of fundamental studies on the cathode active materials for a lithium secondary cell using geometrically well-defined sample electrodes, thin films of spinel LiMn204on a platinum plate were investigated in this work in an LiCl04/propylene carbonate solution. These pyrolytically prepared films exihibit reversible extraction/insertion behavior for lithium under galvanostatic charge/discharge cycling between 4.3-3.5 V. The chemical diffusion coefficient of lithium in LixMn204determined by the galvanostatic intermittent titration technique (GITT) was in the order of 10−7-10−10cm2- s−1within a spinel single-phase region of 0.6<x<1.0 and increased with increasingx.

Li Ion diffusion measurements in crystalline and amorphous V2O5 thin-film battery cathodes

1999 ◽  
Vol 575 ◽  
Author(s):  
Jeanne M. McGraw ◽  
Christian S. Bahn ◽  
Philip A. Parilla ◽  
John D. Perkins ◽  
Dennis W. Readey ◽  
...  
Keyword(s):  
Diffusion Coefficients ◽  
Single Phase ◽  
General Trend ◽  
Pulsed Laser ◽  
Chemical Diffusion ◽  
Laser Deposition ◽  
Ion Diffusion ◽  
Thin Film Battery ◽  
Li Ion ◽  
Titration Technique

ABSTRACTThin films of crystalline and amorphous V2O5 were deposited by pulsed laser deposition (PLD) and the chemical diffusion coefficients, , were measured by the potentiostatic intermittent titration technique (PITT). In crystalline V2O5 films, the maximum and minimum were found to be 1.7 × 10−2 cm2/s and 5.8 × 10−15 cm2/s respectively, with a general trend for to rise in single-phase regions. The changes in correlated well to the known phases in LiV2O5. In amorphous V2O5 films, exhibited a smooth, continuous decrease as the Li concentration increased.

Performance Impacts of Tailored Surface Geometry in Li-Ion Battery Cathodes

2013 ◽  
Author(s):  
George J. Nelson
Keyword(s):  
Surface Area ◽  
Solid Phase ◽  
Particle Surface ◽  
Surface Characteristics ◽  
Analytical Models ◽  
Li Ion Battery ◽  
Fractal Structures ◽  
Surface Geometry ◽  
Trade Offs ◽  
Li Ion

Analytical models developed to investigate charge transfer in Li-ion battery cathodes reveal distinct transport regimes where performance may be limited by either microstructural surface characteristics or solid phase geometry. For several cathode materials, particularly those employing conductive additives, surface characteristics are expected to drive these performance limitations. For such electrodes gains in performance may be achieved by modifying surface geometry to increase surface area. However, added surface area may present a diminishing return if complex structures restrict access to electrochemically active interfaces. A series of parametric studies has been performed to better ascertain the merits of complex, tailored surfaces in Li-ion battery cathodes. The interaction between lithium transport and surface geometry is explored using a finite element model in which complex surfaces are simulated with fractal structures. Analysis of transport in these controlled structures permits assessment of scaling behavior related to surface complexity and provides insight into trade-offs in tailoring particle surface geometry.

scholarly journals Modified method of conductometric data analysis to calculate the conductivity of surfactant ions

2019 ◽  
Vol 124 ◽  
pp. 03009
Author(s):  
O. S. Zueva
Keyword(s):  
Infinite Dilution ◽  
Specific Conductivity ◽  
Total Conductivity ◽  
Mathematical Form ◽  
Modified Method ◽  
Straight Line ◽  
Ion Conductivities ◽  
Electrical Conductivities ◽  
Minimum Number ◽  
Onsager Theory

Methodology for simple analytical refinement of the equivalent electrical conductivities of surfactant ions and counterions was proposed in the framework of the Debye – Hückel – Onsager theory as applied to surfactant dispersions at various concentrations. The developed methodology is based on the use of the mathematical form for the concentration dependencies of the specific conductivity in the premicellar region and makes it possible to calculate the equivalent conductivities of surfactant ions both under infinite dilution conditions and near the CMC. One of the advantages of the described method is the possibility of calculating the ion conductivities in the presence of a minimum number of experimental points (formally, a straight line can be constructed and its tangent of the angle of inclination can be determined even by two points corresponding to region 0.2 CMC — 0.8 CMC). Using the values of the equivalent conductivities of surfactant ions and counterions calculated for the required concentrations, allows to determine the parameters of the solution more accurately, including the contribution of micelles to the total conductivity of the solution.

scholarly journals Modified method of conductometric data analysis to calculate the degree of ionization and conductivity of micelles

2019 ◽  
Vol 124 ◽  
pp. 03008
Author(s):  
O. S. Zueva
Keyword(s):  
Data Analysis ◽  
Micellar Solution ◽  
Specific Conductance ◽  
Total Conductivity ◽  
Calculation Methods ◽  
Degree Of Ionization ◽  
Modified Method ◽  
High Concentrations ◽  
Onsager Theory ◽  
New Formula

Methods for calculation of specific conductance of ions and micelles and the degree of micelle ionization using conductometric data in various approximations of the Debye – Hückel – Onsager theory were considered. The analysis of the existing calculation methods was carried out to identify their drawbacks and to suggest ways of their elimination. The calculation method of the micellar parameters on the basis of conductometric data using micellar size was modified, and a new formula for determining the degree of micelle ionization was obtained. All calculations using the modified method were performed in the first and the second approximations, and the newly obtained values of the micellar parameters are in greater agreement with the results of other studies. Based on the calculations performed, it was shown that the contribution of micelles to the total conductivity of micellar solution cannot be neglected, since at high concentrations the contribution of micelles exceeds the contribution of counterions and can exceed 50%.

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