Impedance Spectroscopy

Evgenij Barsoukov's collection of impedance spectroscopy resources


Abstracts and full-text papers of Evgenij Barsoukov

(full-text links to be added soon)

G.S.Popkirov, E. Barsoukov, "In situ impedance measurements
during oxidation and reduction of conducting polymers:
significance of capacitive currents",
J. Electroanal. Chem. 383 (1995) 155

An attempt has been made to model mathematically the capacitive component of the current obtained in cyclic voltammograms of polymer-coated electrodes. The capacitance data used were obtained by means of electrochemical impedance spectroscopy (EIS) measurements performed in situ during the potential sweeps. It was shown that the capacitive current flowing during the oxidation and reduction processes strongly depends on both the low frequency capacitance of the polymer and its changes during the sweep.

G.S. Popkirov, E. Barsoukov and R.N. Schindler "Electrochemical
impedance spectroscopy of twin working electrodes bridged with
conducting polymer layer", Electrochim. Acta 40 (1995) 1857

A new technique is described for electrochemical impedance spectroscopic (EIS) investigations in the plane of a polymer layer coating an electrode without crossing the interface polymer-electrolyte. For this purpose a twin-working electrode configuration was constructed, that consists of two practically identical electrodes with a gap of a few micrometers width between them. This gap was bridged by a polymer layer of polybithiophene. Its behavior was studied during electrochemical deposition on the twin electrode and during transition from insulating to conducting state upon oxidation. It is shown that for lower frequencies the impedance spectra obtained depend predominantly on the polymer conductivity and are not determined by the macroscopic external polymer/electrolyte interface. Contribution of capacitive ac currents that cross microscopic internal polymer-electrolyte interfaces in the deep pores of the polymer become considerable only in the higher frequency range.

G.S. Popkirov, E. Barsoukov and R.N. Schindler
"Investigation of conducting polymer electrodes
by impedance spectroscopy under galvanostatic conditions"
J. Electroanal. Chem., 425 (1997) 209-216

Electrochemical impedance spectroscopy was used to investigate the electrochemical polymerization of bithiophene under galvanostatic conditions. The impedance spectra obtained on layers with different thicknesses were analyzed by a fitting procedure, based on theoretical models known from the literature. It was shown that the model of Ho at al. (C. Ho, I.D. Raistrick and R.A. Huggings, J.Electrochem. Soc., 127 (1950) 343) can be applied successfully in studying the impedance spectra of relatively thin polybithiophene layers, deposited at low current density. The model of Paash at al. (G. Paasche, K. Micka and P. Gersodorf, Electrochim. Acta, 38 (1993) 2653) in a simplified form is better suited to describe the spectra of thicker, supposedly porous polymer layers, obtained at higher current density. It was suggested that the deposition of polymer film onto a metal electrode follows a 3D growth mechanism during the first stages of polymerization, and pseudo-2D growth form polymerization at charges higher than 15 to 20 mC/cm-2. Important parameters of the polymer film, such as the apparent diffusion coefficient, apparent diffusion length, ionic and polymer layer thickness were estimated.

Jong Hyun Kim, Jong Hun Kim, Evgenij Barsoukov, Chul Oh Yoon, and Hosull Lee
“Li NMR Study of Li Intercalated Carbons Prepared by Electrochemical Method”, Mol.Chyst.Liq.Cryst. 310 (1998) 297

Li solid-state nuclear magnetic resonance (NMR) is employed to investigate the mechanism of electrochemical lithium-intercalation in various carbon materials. Multiple resonance line shapes observed in fully lithiated carbons indicate that several intercalant sites exist under distinct spin-interaction environment, and they are substantially dependent upon physical nature of host structure. The temperature dependence of resonance spectra in disordered carbons prepared at relatively low carbonization temperature considerably differs from that observed in lithiated carbons with graphite structure.

Evgenij Barsoukov, Jong Hyun Kim, Jong Hun Kim, Chul Oh Yoon, and Hosull Lee
“Effect of Low-Temperature Conditions on Passive Layer Growth on Li Intercalation Materials: In sity Impedance Study”, J.Electrochem.Soc. 145/8 (1998) 2711.

Electrochemical impedance spectroscopy has been applied to investigate the formation of insulating layers at the surfaces of microscopic particles of mesocarbon microbeads (MCMB), graphite and hard carbon during the first Li-intercalation into these materials at ambient temperature as well as at -20 oC. Investigations were carried out in a 3-electrode sandwich cell, designed for impedance measurements in the frequency range 64kHz-5mHz. The impedance spectra, obtained in the potential range 1.5 and 0.02 V during the first charge, were analyzed by complex non-linear least square fits. A new model, taking into account the porous structure of the intercalation material, electrochemical processes at the interface, as well as spherical diffusion of Li ions toward the centers of the particles, has been used for this analysis. First intercalation at -20oC results in formation of an insulating layer, which is about 90 times thinner than in the room temperature case, as concluded from the analysis of experimental results. The irreversible capacity loss, which is 1.3 times larger at -20 oC than at room temperature, is ascribed to the formation of a porous precipitate of electrolyte decomposition products on the particle surface. Additional reduction at room temperature results in irreversible capacity loss of 26% from the initial value, and formation of a composite layer, including low-temperature and room-temperature deposited components.

Evgenij Barsoukov, Jong Hyun Kim, Chul Oh Yoon, and Hosull Lee
“Kinetics of lithium intercalation into carbon anodes: in sity impedance investigation of thickness and potential dependence”, Solid State Ionics, 116 (1999) 249.

Electrochemical impedance spectroscopy (EIS) in 3-electrode sandwich configuration was applied to investigate the kinetics of Li intercalation into mesocarbon-microbeads (MCMB) based anodes. A new frequency domain model, considering porous macroscopic structure of the active material and spherical diffusion inside the particles, has been applied to analyze the potential and thickness dependence of impedance spectra. Values of several kinetics-relevant parameters like specific conductivity of the layer of intercalation material (2.6 10-4 S cm-1), chemical diffusion coefficient of Li-ions in MCMB (2.2 10-9 cm2 sec), charge transfer resistance (184 ? cm2), are obtained from the analysis. Applicability of proposed model to prediction of time-domain charge curves has been tested using numerical inversion of Laplace transformation (NILT). The time domain modeling lead to conclusion, that phase nucleation at the boundaries between Li-rich and Li-poor phases coexistent during intercalation is the rate-limiting step at initial stage of the impulse-discharge.

Chul Oh Yoon, Hyun Kyung Sung, Jong Hun Kim, Evgenij Barsoukov, Jong Hyun Kim, Hosull Lee, “The effect of low-temperature conditions on the electrochemical polymerization of polypyrrole films with high density, high electrical conductivity and high stability”, Synthetic metals, 99 (1999) 201.

High-quality polypyrrole-hexafluorophosphate (PPy-PF6) films with high density (~1.4 g/cm3), high conductivity (>300 S/cm for unstretched film) and high electrochemical stability are obtained reproducibly by galvanostatic polymerization at low-temperature conditions. The optimal polymerization current density of Jp=0.02-0.05 mA/cm2 was obtained at the polymerization temperature of Tp=-40oC. The surface morphology of the film sensitively varies depending upon the properties of electrode and its surface conditions. The transport measurements characterize the high-density PPy-PF6 film as a disordered metal close to the boundary of disorder induced metal-insulator (M-I) transition. The X-ray diffraction measurements suggest that partially crystalline structure of PPy-PF6 film is related to the transport properties. The uniaxial stretching induces an increase of the conductivity up to ~930 S/cm in a direction parallel to stretching as well as the anisotropy of conductivity. The comparative studies of thermogravimetric analysis (TGA), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) for PPy-PF6 films prepared at room-temperature and low-temperature conditions show that the latter exhibit better thermal stability as well as electrochemical stability under long oxidative polarization.

Evgenij Barsoukov, Jong Hyun Kim, Chul Oh Yoon, and Hosull Lee, “Universal battery parameterization to yield a non-linear equivalent circuit valid for battery simulation at arbitrary load”, J.Power Sources, 83 1/2 (1999) 61

A method of numerical representation for electrical storage cells based on measurement of wide frequency range impedance spectra at a number of different states of charge and measurement of the depth-of-discharge dependence of equilibrium voltage are developed. Applicability of this method to batteries with various chemistries and sizes are established by comparing numerical prediction to experiment. The model represents all tested batteries with accuracy (less than 1% in average deviation) in processes ranging from time constants of 1 ms to 10 h and from current densities of C/10 to 3C. The method includes the fitting of impedance spectra to physically relevant static linear transmission-line model and the use of parameters determined at different discharge levels to create a non-linear dynamic model. Formalization of the model as a non-linear equivalent circuit enables its direct application as a part of any electric device in digital circuit simulators like SPICE.

Evgenij Barsoukov, Jong Hyun Kim, Dong Hwan Kim, Chul Oh Yoon, and Hosull Lee, “Parametric analysis using impedance spectroscopy: relationship between material properties and battery performance”, Journal of New Materials for Electrochemical Systems, 3, (2000) 303-310.

The possibility of prediction of battery material performance based on parameterization of impedance spectra measured at different states of charge in boundaries of non-linear equivalent circuit model (numerical image) is demonstrated. An impedance parameterization procedure developed in this laboratory was used to obtain all kinetically relevant parameters of LiCoO2 based composite Li-ion battery cathode materials. The accuracy of performance prediction was tested by comparing voltage profiles, calculated on basis of numerical image, at discharge rates ranging from 1/10C to 3C with experimental data. Model parameters were used to compare the relative influence from different kinetic steps on discharge behavior of composite electrode. Predicted thickness dependence of electrode impedance was compared with experimental impedance spectra measured on samples with active material thickness from 20 to 60 ?m. The change of relative contributions of kinetic parameters with thickness has been investigated.

Evgenij Barsoukov, Jee Hwan Jang, and Hosull Lee
"Measurement of Li-ion batteries thermal impedance spectrum using heat-pulse response analysis", J. Power Sources, 109 (2002) 313

A novel characterization of thermal properties of battery has been introduced by defining its frequency-dependent thermal impedance function. Thermal impedance function can be approximated as a thermal impedance spectrum by analyzing experimental temperature transient which is related to the thermal impedance function through Laplace transformation.
In order to obtain temperature transient, a process has been devised to generate external heat pulse with heating wire and to measure the response of battery. This process is used to study several commercial Li-ion batteries of cylindrical type. The thermal impedance measurements have been performed using potentionstat/galvanostate controlled digital signal processor, which is more commonly available than flow-meter usually applied for thermal property measurements.
Thermal impedance spectra obtained for the batteries produced by different manufactures are found to differ considerably. Comparison of spectra at different states of charge indicates independence of thermal impedance on charging state of battery.  It is shown that thermal impedance spectrum can be used to obtain simultaneously thermal capacity and thermal conductivity of battery by non-linear complex least-square fit of the spectrum to thermal-impedance model.

Evgenij Barsoukov, Jee Hwan Jang, and Hosull Lee
"Eectrochemical impedance spectrometer based on carrier function Laplace-transform", J. Electroanal. Chemistry, 536/1, (2002), 109

A novel impedance spectrometer has been developed to obtain good quality spectrum for electrochemical cell or device in the minimum time required by Nyquist theorem for the lowest frequency in spectrum. The new method based on a simple instrumental design resolves the known problems of existing methods such as long measurement time and fairly complicated design of frequency response analyzer (FRA), as well as poor quality of obtained spectrum for pulse-response analysis based systems.
The spectrometer applies a simple excitation such as current pulse, instantly connected resistance, or current interrupt, followed by measurement of response such as voltage or current against time. The response is fitted to an analytical function (carrier function), and the values of parameters obtained in the fit are applied to the expression of analytical Laplace transformation of this function. The carrier function is selected so that it approximates well the transient response of most electrochemical systems.  An analytical expression of impedance function is obtained by dividing the Laplace transform of the carrier function by the the Laplace transform of excitation signal. The frequency dependent impedance spectrum is obtained by evaluating this analytical expression at required frequencies.

E. Barsoukov?, D.H. Kim, H.S. Lee and H. Lee (1); Marina Yakovleva, Yuan Gao and John F. Engel (2),
“Comparison of kinetic properties of LiCoO2 and LiTi0.05Mg0.05Ni0.7Co0.2O2 by impedance spectroscopy”, Solid State Ionics, submitted (2002)
(1) Kumho Chemical Laboratories, Korea Kumho Petrochemical Company
57-1 Hwaam Yuseong, Daejeon 305-348, Rep. of Korea
(2) FMC Corporation

New material based on LiNiO2 with some nickel atoms substituted for other metals has become increasingly popular as cathode materials for Li-ion battery due to higher capacity of LiNiO2 compared to traditionally used LiCoO2 and improved material stability and safety due to substitutes. However, rate capability of new materials was not extensively researched. Purpose of this investigation was to characterize by impedance spectroscopy all major kinetic steps of Li-intercalation into conventional LiCoO2 and substitution stabilized material LiTi0.05Mg0.05Ni0.7Co0.2O2 samples, provided by FMC Corporation. Very wide frequency range of impedance measurements (to 200 ?Hz) with acceptable duration was made possible by using Kumho Chemical Laboratories one-shot FFT-impedance spectrometer. Availability of such low frequency data allowed confident estimation of diffusion and phase-change kinetic parameters. Results were analyzed in terms of transmission-line model considering composite structure of electrode. Effects of particle size and mechanism of samples degradation with cycling were also investigated.

Abstracts and full-text patents of Evgenij Barsoukov

"Method and apparatus for measuring battery capacity by impedance spectrum measurement" Kumho Petrochemical, by C.O.Yoon, E.Barsoukov, J.H.Kim,  Korean Patent No. 264515 (00/6/1), Japan Patent No. 3162346 (01/3/23), US Patent No. 6208147 (01/3/27)

United States Patent  6,208,147
Yoon ,   et al.  March 27, 2001

Method of and apparatus for measuring battery capacity by impedance spectrum analysis
Provided with a method of measuring battery capacity by impedance spectrum analysis, which is to measure a characteristic impedance spectrum of primary and secondary batteries and determine the battery capacity the method including the steps of: (1) measuring the characteristic impedance spectrum of a battery in a predetermined frequency region; (2) determining a parameter from the measured impedance spectrum; (3) monitoring in advance the correlation between the determined parameter and the battery capacity measured by a real-time discharge technique; and (4) determining the battery capacity from the characteristic impedance spectrum of a battery having an unknown capacity based on the monitored correlation.


Inventors:  Yoon; Chul Oh (Taejeon, KR); Barsukov; Yevgen (Taejeon, KR); Kim; Jong Hyun (Seoul, KR)
Assignee:  Korea Kumho Petrochenical Co., Ltd. (Chongno-ku)
Appl. No.:  260438
Filed:  March 2, 1999

"Method of and apparatus for measuring battery capacity using voltage response signal based on pulse current", Kumho Petrochemical, by C.O.Yoon, E.Barsoukov, J.H.Kim, Korean Patent No. 262465 (00/5/2), Japan Patent No. 19234A2 (00/1/21), US Patent No. 6118275 (00/9/12), PCT Application No. 66340A1 (99/12/23, 7 countries including EU, Canada, Israel and Taiwan)

United States Patent  6,118,275
Yoon ,   et al.  September 12, 2000

Method and apparatus for measuring battery capacity using voltage response signal based on pulse current
A method of measuring battery capacity using a voltage response signal based on a pulse current, where the method includes the steps of: measuring a voltage response signal based on a pulse current signal applied to a primary or secondary battery; performing an approximation of the measured voltage response signal to an equivalent circuit model composed of resistors, capacitors and transmission lines to determine the model parameters; and determining the unknown battery capacity from the voltage response characteristics based on a correlation between the measured capacity and the model parameters, which correlation is previously determined by a real-time discharge method, thereby takes a shorter time than a real-time discharge method and delivering efficiency and reliability in determining model parameters of an equivalent circuit which are in close correlation with the charge/discharge condition of the battery.


Inventors:  Yoon; Chul Oh (Taejeon, KR); Barsukov; Yevgen (Taejeon, KR); Kim; Jong Hyun (Seoul, KR)
Assignee:  Korea Kumho Petrochemical Co., Ltd. (Seoul, KR)
Appl. No.:  216181
Filed:  December 18, 1998

"Battery parameterization system" Kumho Petrochemical, by C.O.Yoon, E.Barsoukov, J.H.Kim, Korean Patent Application No. 98-49700 (98/11/19), Japan Patent No. 3190313 (01/5/18),US Patent No. 6160382 (00/12/12), PCT Application No. 31557A1 (00/6/2, 16 countries including EU, Canada, Israel and Taiwan)

United States Patent  6,160,382
Yoon ,   et al.  December 12, 2000

Method and apparatus for determining Characteristic parameters of a charge storage device
A method and an apparatus for determining characteristic parameters of a charge storage device based on a wide frequency range of impedance measurement and a non-linear equivalent circuit model by which the parameters of the non-linear equivalent circuit model indicative of the characteristics of various charge storage devices such as a primary battery, secondary battery, capacitor, supercapacitor and fuel cell are determined, the method comprising the steps of: (1) measuring voltage and current characteristics in a process of charging/discharging of the charge storage device by applying a voltage/current at a predetermined discharge rate; (2) measuring impedance spectra at a predetermined range of frequency by measuring the current and voltage from both terminals of the charge storage device or from an electrical load directly connected to the charge storage device at a plurality of states of charge within the entire charge/discharge interval; and (3) obtaining the parameters of the non-linear equivalent circuit of the charge storage device from the charge or discharge characteristics measured in step (1) and the characteristic impedance spectrum in the predetermined range of frequency measured in step (2).


Inventors:  Yoon; Chul Oh (Taejeon, KR); Barsukov; Yevgen (Taejeon, KR); Kim; Jong Hyun (Seoul, KR)
Assignee:  Korea Kumbho Petrochemical Co., Ltd. (Seoul, KR)
Appl. No.:  358264
Filed:  July 21, 1999

"Laplace transform impedance spectrometer" Kumho Petrochemical, by C.O.Yoon, E.Barsoukov, J.H.Kim, Korean Patent Application No. 8460 (99/3/13), Japan Patent No. 3069346 (00/5/19), US Patent Application No. 746452 (99/12/30), PCT Application (15 countries including EU, Canada, Israel and Taiwan) in process


This disclosure describes a method of measuring impedance based on carrier function Laplace transform. The measurement includes detecting a response signal from a device under test to which signal excitation such as pulse, interrupt or constant load is applied. Resulting data is fitted to a carrier function, selected so as to be capable to provide a good fit and for which an analytical Laplace transform is known, in order to obtain parameters of such function providing best fit. Obtained parameters are further substituted into analytical expression of Laplace transform of carrier function which is used to calculate a frequency dependent impedance function in the Laplace domain. The resulting impedance function is used for calculating the impedance spectrum in a frequency domain and for calculating the measurement error of the frequency domain impedance spectrum using the standard deviations of the parameters, obtained during fitting of time-domain data.


"Method to obtain performance characteristics of electrochemical power source by multidimensional correlation of parameters obtained by measurement", Kumho Petrochemical, by H.K.Sung, E.Barsoukov, J.H.Jang, Korean Patent Application in process, US Patent Application in process

A method of obtaining performance characteristic such as but not restricted to state of charge, state of health, manufacturing quality (grade), cycling life etc. of electrochemical power sources such as primary battery, secondary battery or fuel-cell by multidimensional (also known as multi-variant) correlation between the desired performance characteristic and 2 or more parameters obtained from test measurements performed on the multiple entities of power source having different values of the performance characteristic to be obtained. Test measurement which results are used to obtain parameters employed by this method has to be of shorter time duration or less destructive then the direct measurement of desired performance characteristic, such as but not restricted to impedance measurement.
 Method includes: (a) performing test measurements on multiple power sources of same design but with different values of desired performance characteristic; (b) performing direct measurement of the desired performance characteristic on all electrochemical power sources for which test a) was performed; (c) obtaining 2 or more parameters p1,p2...pN for each of tested power sources by analysis of the results of test measurement performed in a); (d) performing multi-dimensional correlation between the desired performance characteristic and parameters obtained in c) using suitable means  such as but not restricted to localized multi-variant regression to obtain set of regression parameters k1,k2...kN which define multidimensional functional or algorithmic dependence in form V=f(p1,p2...pN, k1,k2...kN) where V is the desired performance characteristic and p1,p2...pN are parameters obtained in c); (e) Performing same test measurement as in (a) on power source with unknown performance charachteristic; (g) obtaining from test measurement results set of 2 or more parameters u1,u2...uN using same method as in c); (h) substituting the obtained in (g) parameters u1,u2...uN into multidimensional functional or algorithmic dependence obtained in (d) and calculating the desired performance characteristic V1=f(u1,u2...uN,k1,k2...kN);


"Method for grouping quality of batteries to build optimal packs using pattern matching technology of impedance spectrum", Kumho Petrochemical, by H.K.Sung, E.Barsoukov, J.H.Jang, Korean Patent Application in process, US Patent Application in process

Method to assign single cells of power sources to several groups in order to improve performance of cell-packs made of cells residing in one group as compared to packs made of randomly selected batteries using parameters obtained by equivalent circuit analysis of impedance spectrum as criterion of grouping. .
 Method includes: (a) Performing impedance spectra measurement measurements on statistically representative number of power sources of same design but with different values of performance. Impedance spectra are measured at several frequencies in frequency range sufficient to obtain parameters of chosen equivalent circuit used for analyzing the spectrum.; (b) finding resistive and capacitate parameters of an equivalent circuit by fitting the measured impedance spectra to known impedance function of the equivalent circuit. Equivalent circuit is chosen so that it allows best possible extrapolation of experimental data to 0 frequency; (c) Using one or several of obtained parameters to calculate approximation of the total resistance (real part of impedance at zero frequency, or DC resistance). (d) Assigning all batteries intended for making battery packs to several groups distinguished by similarity of the  value of total resistance obtained in step d. Selection of group ranges is optimized based on known distribution of the total resistance value of the cells.

Impedance Fitting Programs: download / request links and comparative analysis

This is a “Multiple EIS parameterization” software that uses LEVM engine for fitting but adds to it ability to analyze multiple spectra together and observe tendencies of parameter changes. It supports automatic pre-fit of initial guesses, which eliminate the need of manual guessing and allows forcing of time-constant order to different elements. Graphical presentation of the spectra, results and parameters is also included. In addition it includes rich library of commonly used equivalent circuits and distributed elements (such as limited length diffusion), that can be included as part of the circuits. There is also a graphical circuit editor that allows to create arbitrary circuits, as well as support of user created models as DLLs.

Here are few example screen-shots. Single fit window:

Circuit library:

Unfortunately commercial version of this program is no longer available because project was discontinued.
On the bright side, there was a fully-functional trial version that was freely distributed (get it here). So it looks to me that since
commercial version no longer exists, it is a fair game to use the trial version as long as you want. It appears also that
due to some changes in Windows OS, the expiration mechanism no longer works.

MEISP works fine in Windows XP. Make sure to unzip installer files into a directory with short name without blanks (like c:\install), this installer does not like directories with blanks.

For Vista and Windows 7 users, two comments:

1) This program has very sophisticated help system. For example if you click on a distributed element in circuit editor, and than F1, you will get detailed description of the element with literature references, equations and figures. But, in Vista the MS has for some reason decided not to support their own *.hlp format. No problem – once you try using help and get an error message, follow the link on the error message to install support for *.hlp files from Microsoft web-site. It took me a minute, and you will get help system work as intended.

2) Due to some additional protections in Vista and Windows 7, it does not allow programs to write anything to “Program Files” folder This causes a problem because MEISP is trying to write to its root folder, and  will give error message when you try to create a new circuit.
       No worry, it can be fixed. After installation, copy the entire folder  MEISP from C:\Program Files\Powergraphy into a directory outside of “Program Files”, for example “c:\tools”. Start MEISP.exe from there.
Than create an example project in the directory c:\tools\MEISP\examples\Moly (or some other place, but NOT inside Program Files!). After you add files into the project, do some fitting and save the project, MEISP will remember this directory and will not try to write anything into its original folder. Also make sure to open example files from the new directory where you moved MEISP, and not from the place under “Program Files”.


Happy Fitting!


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