Examination of methods to determine free-ion diffusivity and number density from analysis of electrode polarization

Wang, Yangyang; Sun, Che-Nan; Fan, Fei; Sangoro, Joshua; Berman, Marc B.; Greenbaum, Steve; Zawodzinski, Thomas A.; Sokolov, Alexei P.

doi:10.1103/physreve.87.042308

Cited by 94 publications

(102 citation statements)

References 33 publications

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“…1 for comparison with previous reported data on 5CB [33,36,50]. It can be seen, that the impedance (dielectric) spectra of the liquid crystal 5CB are typical for materials with ionic conductivity [12,13,[30][31][32].…”

Section: Analysis Of the Impedance Frequency Dependencementioning

confidence: 59%

Influence of dielectric layers on estimates of diffusion coefficients and concentrations of ions from impedance spectroscopy

Khazimullin

Lebedev

2019

Phys. Rev. E

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We present the analysis of the impedance spectra for a binary electrolyte confined between blocking electrodes with dielectric layers. An expression for the impedance is derived from Poisson-Nernst-Planck equations in the linear approximation taking into account the voltage drop on the dielectric layer. The analysis shows, that characteristic features of the frequency dependence of the impedance are determined by the ratio of the Debay length and the effective thickness of the dielectric layer. The impact of the dielectric layer is especially strong in the case of high concentrated electrolytes, where the Debay length is small and thus comparable to the effective thickness of the dielectric layer. To verify the model, measurements of the impedance spectra and transient currents in a liquid crystal 4-n-pentyl-4'-cyanobiphenyl (5CB) confined between polymercoated electrodes in cells of different thicknesses are performed. The estimates for the diffusion coefficient and ion concentration in 5CB obtained from the analysis of the impedance spectra and the transient currents are consistent and agree with previously reported data. We demonstrate that calculations of the ion parameters from the impedance spectra without taking into account the dielectric layer contribution lead in most cases to incorrect results. Application of the model to analyze violations of the low-frequency impedance scaling and contradictions in the estimates of the ion parameters recently found in some ionic electrolytes are discussed. * maxim@anrb.ru arXiv:1804.04843v1 [cond-mat.soft]

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Section: Analysis Of the Impedance Frequency Dependencementioning

confidence: 59%

Influence of dielectric layers on estimates of diffusion coefficients and concentrations of ions from impedance spectroscopy

Khazimullin

Lebedev

2019

Phys. Rev. E

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“…). Although the Debye description of a charged double layer is good for dilute solutions, it is known to break down at charge carrier concentrations as low as 10 mM . The breakdown of the Debye model results in a systematic underestimation of charge density, increasing in magnitude with concentration, allowing only qualitative comparisons of relative charge densities at high concentrations.…”

Section: Resultsmentioning

confidence: 99%

“…The breakdown of the Debye model results in a systematic underestimation of charge density, increasing in magnitude with concentration, allowing only qualitative comparisons of relative charge densities at high concentrations. It does, however, permits determination of lower limits for the actual carrier concentration within a material, and provides an accurate measure of E a for ion pairing even at high concentrations …”

Section: Resultsmentioning

confidence: 99%

Probing microphase separation and proton transport cooperativity in polymer‐tethered 1H‐tetrazoles

Chaloux

Ricks-Laskoski

Miller

et al. 2014

J Polym Sci B Polym Phys

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To elucidate the driving forces for phase separation and proton conductivity in polystyrenic alkoxy 1H‐tetrazole (PS‐Tet), an analogous polystyrenic alkoxy carboxylic acid (PS‐HA) was synthesized and the conductivity and chain dynamics of both materials measured. Proton and polymer motions illustrate dramatic differences in the nonaqueous behavior of carboxylic acids and 1H‐tetrazoles, belying similarities in their aqueous properties. Exceptional interactions between 1H‐tetrazoles drive phase separation not observed in PS‐HA or reported for other azole‐containing homopolymers. PS‐HA and PS‐Tet exhibit both dry (0% relative humidity) and hydrated proton dissociations proportional to their aqueous pKas, with residual water acting as the proton acceptor in both polymers. While water is the sole contributor to mobility in PS‐HA, PS‐Tet exhibits dynamic interactions with water allowing 1H‐tetrazole moieties to contribute to proton conduction even in the hydrated state. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 1375–1387

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“…It follows that the PNP-model is valid only in the limit of small bulk density of ions, in such a manner that the influence of the ions on the dielectric constant can be neglected. 13 The solution of the fundamental equations of the model requires to define the boundary conditions on current densities at the electrodes.…”

Section: Introductionmentioning

confidence: 99%

Evidence for frequency dependent diffusion in hydrogel

Scalerandi

Barbero

Alexe-Ionescu

2014

Journal of Applied Physics

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The electrical response of a hydrogel to an external periodic voltage is investigated by means of the impedance spectroscopy technique. We show that the experimental data, obtained in the linear regime, for the real and imaginary parts of the electric impedance can be interpreted using the Poisson-Nernst-Planck model, taking into account the frequency dependence of viscosity and the non blocking character of the electrodes. We estimate the parameters (ion density, electrode conductivity, and diffusion coefficient) when varying the quantity of salt in the hydrogel. Our experimental data indicate that the bulk density of ions increases with the salt concentration, tending to a saturation value, whereas the electrode conductivity is independent of it. Finally, the parameters defining the dispersion of the diffusion coefficient depend weakly on the salt concentration.

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Examination of methods to determine free-ion diffusivity and number density from analysis of electrode polarization

Cited by 94 publications

References 33 publications

Influence of dielectric layers on estimates of diffusion coefficients and concentrations of ions from impedance spectroscopy

Influence of dielectric layers on estimates of diffusion coefficients and concentrations of ions from impedance spectroscopy

Probing microphase separation and proton transport cooperativity in polymer‐tethered 1H‐tetrazoles

Evidence for frequency dependent diffusion in hydrogel

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