scholarly journals Verification of Redox Flow Batteries’ Functionality by Electrochemical Impedance Spectroscopy Tests

Batteries ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 58 ◽  
Author(s):  
Daniel Manschke ◽  
Thorsten Seipp ◽  
Sascha Berthold ◽  
K. Friedrich
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Comparison Method ◽  
Redox Flow Batteries ◽  
Current Voltage ◽  
Flow Batteries ◽  
Quantitative Statement ◽  
Characteristic Values ◽  
Eis Measurements

The state-of-the-art functionality test of classic redox-flow-stacks measures the current–voltage characteristic with the technical electrolyte. This research paper aims to simplify the validation of redox flow batteries’ functionality by conducting electrochemical impedance spectroscopy (EIS) on redox flow stacks. Since the electrolyte used in the batteries is usually toxic and aggressive, it would be a significant simplification to verify the functionality with an alternative, non-toxic fluid. EIS measurements on batteries with larger sized electrodes, multiple cells, and different fluids were performed. It was demonstrated that all impedances are repeatable, thereby validating this procedure as a qualification method for full-size and complex batteries with an alternative fluid. EIS measurements were able to detect deliberately manipulated cells. This research uses three different analysis methods for the acquired data to identify errors. The respective approaches are, firstly, (1) a comparison of the Nyquist plots; secondly, (2) a comparison of the Bode plots; and thirdly, (3) a comparison of the calculated characteristic values of the equivalent circuits. The analysis found that all methods are suitable to detect errors in the batteries. Nevertheless, the bode-plot comparison method proves to be especially advantageous, because it enables a quantitative statement.

Resolving Losses at the Negative Electrode in All-Vanadium Redox Flow Batteries Using Electrochemical Impedance Spectroscopy

2014 ◽  
Vol 161 (6) ◽  
pp. A981-A988 ◽  
Author(s):  
Che-Nan Sun ◽  
Frank M. Delnick ◽  
Douglas S. Aaron ◽  
Alexander B. Papandrew ◽  
Matthew M. Mench ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Negative Electrode ◽  
Redox Flow Batteries ◽  
Flow Batteries ◽  
Vanadium Redox

scholarly journals Regularized Collocation in Distribution of Diffusion Times Applied to Electrochemical Impedance Spectroscopy

2020 ◽  
Vol 20 (3) ◽  
pp. 517-530 ◽  
Author(s):  
Sergei V. Pereverzev ◽  
Sergiy G. Solodky ◽  
Vitalii B. Vasylyk ◽  
Mark Žic
Keyword(s):  
Integral Equation ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Numerical Experiments ◽  
Electrochemical Impedance ◽  
Synthetic Data ◽  
Numerical Implementation ◽  
Integrable Kernel ◽  
Weighted Functional Spaces ◽  
Eis Measurements

AbstractThis paper is inspired by recently proposed approach for interpreting data of Electrochemical Impedance Spectroscopy (EIS) in terms of Distribution of Diffusion Times (DDT). Such an interpretation requires to solve a Fredholm integral equation of the first kind, which may have a non-square-integrable kernel. We consider a class of equations with above-mentioned peculiarity and propose to regularize them in weighted functional spaces. One more issue associated with DDT-problem is that EIS data are available only for a finite number of frequencies. Therefore, a regularization should unavoidably be combined with a collocation. In this paper we analyze a regularized collocation in weighted spaces and propose a scheme for its numerical implementation. The performance of the proposed scheme is illustrated by numerical experiments with synthetic data mimicking EIS measurements.

scholarly journals Impedimetric Characterization of Interdigitated Electrode Arrays for Biosensor Applications

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 899 ◽  
Author(s):  
Elisabeth Kostal ◽  
Stephan Kasemann ◽  
Can Dincer ◽  
Stefan Partel
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Gap Size ◽  
Electrode Arrays ◽  
Electrode Gap ◽  
Interdigitated Electrode ◽  
Eis Measurements ◽  
Biosensor Applications

We present recent results of the electrochemical impedance spectroscopy (EIS) measurements for interdigitated electrode arrays (IDAs) ranging from several micrometers down to hundreds of nanometers. Simulations have shown that the electric field strength between the electrodes scales with the gap size. Therefore, electrodes of varying gap sizes were fabricated and functionalized with ssDNA to empirically validate these findings. The results have shown that the impedimetric response strongly correlates with the width of the electrode fingers: the smaller the electrode gap, the larger the impedance increase.

scholarly journals Detection of the Plant Pathogen Pseudomonas Syringae pv. Lachrymans on Antibody-Modified Gold Electrodes by Electrochemical Impedance Spectroscopy

Sensors ◽  
2019 ◽  
Vol 19 (24) ◽  
pp. 5411 ◽  
Author(s):  
Zofia Cebula ◽  
Sabina Żołędowska ◽  
Karolina Dziąbowska ◽  
Marta Skwarecka ◽  
Natalia Malinowska ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Pseudomonas Syringae ◽  
Electrochemical Impedance ◽  
Reference Method ◽  
Sample Pretreatment ◽  
Label Free ◽  
Crop Species ◽  
Eis Measurements ◽  
Impedimetric Immunosensor

The present work describes an impedimetric immunosensor for Pseudomonas syringae pv. lachrymans (Psl) detection. This pathogen infects many crop species causing considerable yield losses, thus fast and cheap detection method is in high demand. In the assay, the gold disc electrode was modified with 4-aminothiophenol (4-ATP), glutaraldehyde (GA), and anti-Psl antibodies, and free-sites were blocked with bovine serum albumin (BSA). Sensor development was characterized by cyclic voltammetry (CV) and antigen detection by electrochemical impedance spectroscopy (EIS) measurements. Seven analyzed strains of Psl were verified as positive by the reference method (PCR) and this immunoassay, proving sensor specificity. Label-free electrochemical detection was in the linear range 1 × 103–1.2 × 105 CFU/mL (colony-forming unit) with an R2 coefficient of 0.992 and a detection limit (LOD) of 337 CFU/mL. The sensor did not interfere with negative probes like buffers and other bacteria. The assay was proven to be fast (10 min detection) and easy in preparation. The advantage was the simplicity and availability of the verified analyte (whole bacteria) as the method does not require sample pretreatment (e.g., DNA isolation). EIS biosensing technique was chosen as one of the simplest and most sensitive with the least destructive influence on the probes compared to other electrochemical methods.

scholarly journals Electrochemical Impedance Spectroscopy (EIS) in Food, Water, and Drug Analyses: Recent Advances and Applications

2020 ◽  
Author(s):  
Marwa El-Azazy
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
High Sensitivity ◽  
Electrochemical Technique ◽  
Water Safety ◽  
Food Contaminants ◽  
Sensitivity And Selectivity ◽  
Ac Current ◽  
Eis Measurements

Electrochemical impedance spectroscopy (EIS) is a potent electrochemical technique with a variety of applications. EIS measurements involve the application of an alternating current (AC) voltage (or current) to the system under investigation, followed by measurement of the response in the form of AC current (or voltage) as a function of frequency. By and large, EIS is an exceptionally attractive in terms of applications. Being nondestructive with a feasibility of implementation to the system to be measured and the usefulness of data obtained in characterizing the studied systems, electrochemical impedance spectroscopy has realms of applications. As food and water safety and security is becoming a universal concern, the need for a technique that can detect water and food contaminants with relatively high sensitivity and selectivity is evolving. EIS has started to realize its potential with a wide-term use in water and food analyses.

scholarly journals A New Integrated Multi-Pathogen In Situ Detection Platform Using Electrochemical Impedance Spectroscopy

Proceedings ◽  
2018 ◽  
Vol 2 (13) ◽  
pp. 1506
Author(s):  
Karlheinz Kellner ◽  
Jörg Ettenauer ◽  
Martin Brandl
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Pathogenic Bacteria ◽  
Electrochemical Impedance ◽  
Cell Model ◽  
Successful Implementation ◽  
Eis Measurements ◽  
In Situ Detection ◽  
Multiple Pathogens

Scientists are always searching for inventions and developing new methods for the detection of pathogenic bacteria in drinking water. Some of those techniques are based on electrochemical reactions, performed by a device called potentiostat. For in situ analysis, there is a high demand for hardware efficient instruments with a customized set of requirements including Electrochemical Impedance Spectroscopy (EIS) measurements. Therefore, we developed the ‘EcoStat’ device. As outcome of further developments, we demonstrate the successful implementation of an EIS feature and a multiplexing unit to achieve a detection platform for multiple pathogens. We present results performed on a simplified Randles Cell model.

Rapid analytical instrumentation for electrochemical impedance spectroscopy measurements

2019 ◽  
Author(s):  
yuan hu ◽  
Sean Brahim ◽  
Stefan Maat ◽  
Patricia Davies ◽  
Arpan Kundu ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Impedance ◽  
Low Cost ◽  
Wide Frequency Range ◽  
Measurement Time ◽  
Frequency Bands ◽  
Commercial Instrument ◽  
Adaptive Measurement ◽  
Eis Measurements

This work reports a low-cost custom electrochemical instrument capable of performing rapid and accurate electrochemical impedance spectroscopy (EIS) for supercapacitors over a broad frequency band (10 mHz to 2 kHz). Conventionally, EIS is measured via sinusoidal perturbations; however, such an approach suffers from lengthy measurement time. Chirp signals have been shown previously to reduce EIS measurement time for supercapacitors for relative narrow frequency bands (1 Hz to 2 kHz). However, to characterize supercapacitors comprehensively, much broader frequency bands are required. Here, we present a custom instrument with an adaptive measurement algorithm for performing EIS measurements in a wide frequency range of 10 mHz to 2 kHz with low measurement uncertainties. The results obtained using this new technique has been validated here with a commercial instrument on several types of supercapacitors. Furthermore, measurement time on average decreases from 1500 s to less than 400 s. The overall cost of the custom instrument is 90% lower as compared to the commercial instrument. The custom instrument's accuracy, time efficiency and low cost are expected to benefit electrochemical researchers.

scholarly journals Enrichment-Free Rapid Detection of Phthalates in Chinese Liquor with Electrochemical Impedance Spectroscopy

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 901
Author(s):  
Xinyue Jiang ◽  
Yuqun Xie ◽  
Duanji Wan ◽  
Fuping Zheng ◽  
Jun Wang
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Metal Ion ◽  
Electrochemical Impedance ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Faradaic Impedance ◽  
Chinese Liquor ◽  
Non Invasive ◽  
Eis Measurements

A non-invasive real-time detection technique for phthalates in Chinese liquor is proposed in this paper. This method is based on the measurement of Faradaic impedance in the presence of a redox probe, [Fe(CN)6]3−/4−, upon the absorption of phthalates to the graphene electrode surface. This absorption activity is according to the π–π stacking interactions between phthalates and the graphene working electrode which allows direct sampling and analyte preconcentration. The absorption of phthalates retards the interfacial electron-transfer kinetics and increases the charge-transfer resistance (Rct). Numerical values of Rct were extracted from a simulation of electrochemical impedance spectroscopy (EIS) spectra with the corresponding equivalent circuit. Cathodic polarization was employed prior to EIS measurements to effectively eliminate the metal ion interference. The results yielded a detection limit of 0.024 ng/L for diethyl phthalate (DEP) with a linear range from 2.22 ng to 1.11 µg. These results indicate a possibility of developing a household sensor for phthalate determination in Chinese liquor.

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