On the Application of the Kramers‐Kronig Relations to Evaluate the Consistency of Electrochemical Impedance Data

Esteban, J. M.; Orazem, Mark E.

doi:10.1149/1.2085580

Cited by 87 publications

(49 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…0.3 V, and 0.2 V is shown in Figure 6. The data did not appear to be Kramers-Kronig consistent, 41 presumably because even though the voltage degradation rate appears manageable, the baseline of the EIS measurement was changing over the time scale of the experiment, 2-3 hours. We were able to measure the internal cell resistance and charge transfer resistances from the EIS.…”

Section: Resultsmentioning

confidence: 90%

A Direct Methanol Alkaline Fuel Cell Based on Poly(phenylene) Anion Exchange Membranes

Janarthanan

Pilli

Horan

et al. 2014

J. Electrochem. Soc.

View full text Add to dashboard Cite

The Investigation of the performance of poly(phenylene) based anion exchange membranes (AEMs) in a direct methanol fuel cell is reported. The fuel cell performances were tested with different anode gas diffusion layers as a function of concentrations of fuel and electrolyte using two commercially available platinum catalysts supported on carbon. Normalized current density values demonstrated good performance for a poly(phenylene) AEM, with a cation consisting of six methylene spacers attached to a trimethyl ammonium group, with a maximum current density of 11.8 mA cm −2 mg −1 in a KOH free fuel. The platinum catalyst (46%) from Tanaka showed a better performance (10.4 mA cm −2 mg −1 ) compared to the platinum catalyst from E-TEK (5.1 mA cm −2 mg −1 ) in 1M methanol fuel feed under identical conditions. We observed that the MEA with a Zoltek gas diffusion layer on the anode showed the best performance (226 mA cm −2 and 53.8 mW cm −2 ) in the presence of KOH, suggesting that a hydrophilic gas diffusion layer plays a significant role in improving the fuel cell performance. A durability test for a MEA in 1M methanol and 1M KOH for 67 h showed an overall degradation rate of 400 μV h Direct methanol fuel cells based on proton exchange membranes (PEMs) have received considerable attention, as compared to hydrogen fuel cells, they have potential system simplicity, high system energy density, improved volumetric fuel storage and fuel supply. 1,2Direct methanol alkaline fuel cells (DMAFCs) which employ an anion exchange membrane (AEM) electrolyte are more attractive than devices based on PEMs as they should provide improved electrode kinetics, simple water management, lower methanol permeability, and use of non-platinum metal catalysts.3-6 Solid-state AEM electrolytes are more attractive than the conventional liquid KOH electrolytes as the carbonates and bicarbonates formed during operation do not precipitate as the cation is the AEM, and although adding an additional ionic resistance to the electrode, do diffuse through the cationic ionomer. 7,8 In spite of these advantages, it is important to note that except for a few reports, high performance in DMAFCs are shown only in the presence of the aqueous basic electrolyte, even for commercially available AEMs.9,10 In general, alkaline DMFC studies employ commercially available AEMs, such as Tokuyama A-006, A-010, Fumatech FAA-2, and Morgane ADP from Solvay. [9][10][11][12][13][14][15][16] Radiation grafted membranes have been demonstrated to be promising AEMs for DMAFCs with a KOH free methanol fuel.17,18 Still a great amount of research is being focused on improving the performance of available commercial AEMs as well as on development of new AEMs to achieve stable, highly conducting, and mechanically robust membranes for fuel cells with high performance and long durability.There are very few alkaline direct methanol fuel cell reports where neat methanol is used and aqueous methanol is still the fuel of choice, in fact high power densities have only been achieved for these ...

show abstract

Section: Resultsmentioning

confidence: 90%

A Direct Methanol Alkaline Fuel Cell Based on Poly(phenylene) Anion Exchange Membranes

Janarthanan

Pilli

Horan

et al. 2014

J. Electrochem. Soc.

View full text Add to dashboard Cite

show abstract

“…The calculated component can then be compared with the experimental one; and conclusions about the compliance of the KK relations can be extracted. The main limitation of this method is that KK relations direct integration requires data in the frequency range from 0 to infinity [40]; and the data obtained in practice only cover a finite frequency range. Thus, extrapolation of the data is required.…”

Section: Kramers-kronig Relationsmentioning

confidence: 99%

“…Thus, extrapolation of the data is required. Several extrapolation methods have been used in literature: the Kendig method [41][42]; the Macdonald method [43]; the Haili method [44] and the Esteban-Orazem method [40]. However, any of these methods can be used if the measured frequency range is too narrow; or if the maximum imaginary component point has not been obtained experimentally [36].…”

Section: Kramers-kronig Relationsmentioning

confidence: 99%

Montecarlo based quantitative Kramers–Kronig test for PEMFC impedance spectrum validation

Giner-Sanz

Ortega

Pérez-Herranz

2015

International Journal of Hydrogen Energy

View full text Add to dashboard Cite

Electrochemical Impedance Spectroscopy (EIS) is a very powerful tool to study the behaviour of electrochemical systems. At present, it is widely used in the fuel cell field in order to study challenging cutting edge issues as membrane drying or gas diffusion layer flooding amongst others. The proper analysis of impedance data requires the fulfilment of four fundamental conditions: causality, linearity, stability and finiteness. The non compliance with any of these conditions may lead to biased, or even misguided, conclusions. Therefore it is critical to verify the compliance of these conditions before accepting any analysis performed on an experimental spectrum. This is even more important in a fuel cell experimental spectrum analysis, since fuel cells are markedly non stationary systems. The aim of this work is to establish an impedance spectrum quantitative validation technique to validate the whole experimental spectrum and to identify the individual points within a spectrum that do not comply any of the four conditions, in order to remove these inconsistent points from the analysis. The designed validation method consists in a Kramers-Kronig (KK) validation test, by equivalent electrical circuit fitting, coupled with a Montecarlo error propagation method. In a first step, the experimental spectrum is fitted to a particular electrical equivalent circuit, which satisfies the KK relations. Then, in a second step, a statistical Montecarlo method is used in order to propagate the model fitting parameter uncertainty through the model. Using this approach, a consistency region is built for a given confidence level: the experimental points inside this region are considered consistent for the given confidence level, whereas the outside points are rejected. The method was used on PEMFC experimental impedance spectra; and it successfully managed to identify inconsistent points, associated to no stationarities.2

show abstract

“…(33), cf. Esteban and Orazem, 1991), we can thereby compare fitting parameters of Cole-Cole Eq. (38), e.g.…”

Section: Crim Simulationmentioning

confidence: 99%

Wideband impedance spectroscopy from 1mHz to 10MHz by combination of four- and two-electrode methods

Volkmann

2015

Journal of Applied Geophysics

View full text Add to dashboard Cite

Impedance Spectroscopy (IS) measurements allow to study a wide range of polarization mechanisms associated with different frequency ranges. Experimental devices usually cover limited frequency ranges with sufficient accuracy. We propose (a) a combination of four-electrode and two-electrode devices and (b) a data combination and mutual verification procedure using the actual sample under test. Hereby, we cover a frequency range from 1 mHz to 10 MHz. The data combination relies on the precondition that any dispersive disturbance decayed at some mutual point within an overlapping frequency range between 1 Hz and 45 kHz. We validate our data combination procedure by IS measurements on simple reference systems and comparison with widely accepted model functions, e.g. the complex refractive index model (CRIM) for high frequency behavior and Kramers-Kronig relations in terms of data consistency. In this respect, our suggested processing approach is superior to two selected alternative approaches. We successfully adapt typical empirical model functions, e.g. multi-Cole-Cole, to the resulting wideband data to show that they are fully applicable for further data analysis.

show abstract

On the Application of the Kramers‐Kronig Relations to Evaluate the Consistency of Electrochemical Impedance Data

Cited by 87 publications

References 14 publications

A Direct Methanol Alkaline Fuel Cell Based on Poly(phenylene) Anion Exchange Membranes

A Direct Methanol Alkaline Fuel Cell Based on Poly(phenylene) Anion Exchange Membranes

Montecarlo based quantitative Kramers–Kronig test for PEMFC impedance spectrum validation

Wideband impedance spectroscopy from 1mHz to 10MHz by combination of four- and two-electrode methods

Contact Info

Product

Resources

About