Constant Phase Element Research Articles

Structural and impedance spectroscopic investigations of eco-friendly alkali phosphoborate glass-ceramics containing zirconium ion.

Glass-ceramics with novel composition xZrO2.7P2O5.19CaO.24Na2O.(50-x)B2O3 (x = 0, 2, 4, 6, and 8mol%) have been synthesized using melt quench technique. The synthesized compositions were characterized and analyzed by X-ray diffraction, field emission scanning electron microscopy, infrared absorption, and impedance spectroscopy. X-ray diffraction profiles of prepared samples confirm the existence of phases corresponding to Na3Ca6(PO4)5 crystal (with crystallite size ~ 23nm). Infrared absorbance spectra reveal the presence of phosphate and borate units (PO3, PO4, BO3, BO4) in the glass matrix. Different dielectric parameters such as dielectric loss, electric modulus, and tangent loss were evaluated. Their variations with temperature and frequency confirm the non- Debye relaxation behavior of prepared samples. A phenomenal description of the capacitive behavior was studied by considering the circuit having a parallel combination of constant phase element and bulk resistance. The conduction is found to be governed by overlapping large polaron tunneling (OLPT) and follow OLPT model. The results indicate that ZrO2 substituted alkali phosphoborate glass-ceramics can be used as eco-friendly and safe dielectric materials.

Highly Ordered Supramolecular Assembled Networks Tailored by Bioinspired H-Bonding Confinement for Recyclable Ion-Transport Materials

Highly Ordered Supramolecular Assembled Networks Tailored by Bioinspired H-Bonding Confinement for Recyclable Ion-Transport Materials

Effect of irradiation on pyroelectric and electrocaloric parameters in lead-free relaxor ferroelectric ceramic

Ferroelectric materials have a renaissance due to various photosensitive characteristics. In this study, temperature-dependent dielectric, impedance, and ferroelectric measurements were carried out on lead-free Ba0.6(Bi0.5Li0.5)0.4TiO3 (BBLT) ferroelectric ceramic under the dark and exposure of monochromatic 405 nm light conditions. Profound analysis of complex impedance spectroscopy shows a noticeable reduction in bulk capacitance, relaxation time, and constant phase element parameters under illuminated conditions. Relevant phenomenological approaches towards modified Cole−Cole models confirm that the light induces photogenerated nonequilibrium charge carriers. Thus, the trapped charges alter the internal electric field distribution energy. Under illumination, the enhanced polarization and corresponding pyroelectric coefficient enhanced by 40 % and ~260 % at 5 Hz and 10 Hz, respectively, at 20 ℃ were observed. The cross-coupled Electrocaloric (EC) parameters ∆T and ∆S enhanced 600 % and 571 % at 10 Hz, respectively, and 219 % and 218 %, at 5 Hz respectively at 20 ℃ under illumination. This study provides a comprehensive understanding and new insights into the light-dependent dielectric, ferroelectric, pyroelectric and electrocaloric mechanisms in BBLT electroceramics, which encourages the design of modern thermal sensor devices.

A compact model of the ZARC for circuit simulators in the frequency and time domains

Equivalent-circuit models containing fractional-order elements are often employed to make use of fractional-order calculus in the frequency and time domains in a variety of applications. Many of these circuits contain constant-phase elements that appear in parallel with a resistor in a configuration called ZARC. But to avoid fractional order derivatives and include it in circuit simulators, the ZARC itself can also be replaced by equivalent circuit models that only contain integer order elements, such as resistors and capacitors. In this article, a novel compact model is presented to substitute the ZARC by a multiple-RC network. This model is valid for a continuous value of the order exponent and is applicable over a very wide range of frequencies, making it useful in both the frequency and time domains. Since it uses only basic functions and operators, it has been easily implemented as a subcircuit in circuit simulators. The validity of the model has been verified and it has been compared with some previously proposed passive circuit models. The model has also been discussed in relation to the initialization problem, which is an often overlooked challenge in fractional-order circuits.

Salt Solution Concentration Effects on the Electrochemical Impedance Spectroscopy of Poly(3,4‐ethylenedioxythiophene) (PEDOT)

AbstractPoly(3,4‐ethylenedioxythiophene) (PEDOT) has become a widely used modifier for biomedical electrodes because of its ability to significantly decrease the impedance at low frequencies (below 1 kHz). However, in past studies the role of the solution concentration (ionic conductivity) on the electrochemical impedance behavior has not been well established. Here we describe the electrochemical impedance spectroscopy of the conjugated polymer (PEDOT) using standard screen‐printed electrodes and various standard salt (NaCl) solutions with known conductivities from 1.0E‐2 S/cm to 3.1E‐6 S/cm. Changing the conductivity of the salt solution used for impedance measurements had a dramatic influence on the experimentally obtained spectra. An equivalent circuit consisting of a constant phase element in series with a parallel resistor and second constant phase element was used to match and describe these systems. Our results make it possible to better elucidate the influence of electrode, solution, and polymer coating on the resulting impedance response.

Evaluation of Conducting and Tensile Properties of Reduced Graphene Oxide/ Polybutylene Adipate Terephthalate (Rgo/Pbat) Nanocomposites

This study was focused on evaluation of conducting and tensile properties of rGO/ Polybutylene adipate terephthalate (PBAT) nanocomposite intended to use in electronic applications which require biodegradability. This study was also considered to be worthwhile since very little work has been done in this regard so far. PBAT was specifically selected for the study as it is an extensively used biodegradable polymer for variety of applications. The solvent casting method was employed to prepare rGO/PBAT nanocomposites where rGO was dispersed in a solution of PBAT by ultrasonication followed by evaporation of the solvent components. Electrical conductivity (σ) of rGO/PBAT nanocomposites showed a percolation behavior as rGO content was increased from the 0.5 % to 1.5 % (σ increased drastically with the increase of rGO content). The percolation threshold was approximately 0.0045, (i.e., 0.75 w/w % of rGO). The average critical exponent (t) related to the percolation theory was 1.49 ± 0.19 which is well within the expected range 1< t < 2. According to impedance studies, the electrical impedance of GO/PBAT composites decreased with the increasing rGO content, which agreed well with the behavior of the electrical conductivity investigated previously. The same equivalent circuit was shown by each composite except the values for constant phase element CPE and resistor R; the equivalent electrical circuit was a parallel combination of CPE and R. The dielectric analysis of the composites indicated that dielectric parameters ϵ”, ϵ’ and dissipation factor increased significantly with increasing rGO content. The tensile strength of the composites was better than that of neat PBAT up to 1.5 % of rGO loading and decreased on further increasing of rGO. However, their tensile strain at break decreased with increasing rGO content. The results indicated that PBAT/rGO polymer composite is promising candidate for various electronic applications.

Ferroelectric and photoelectrochemical studies of lead-free Ba0.925Bi0.05 □0.025(Ti0.65Zr0.30Sn0.05)O3 ceramic and its application to Rhodamine B oxidation under solar light

New materials with general formula Ba 0.925 Bi 0.05 □ 0.025 (Ti 0.65 Zr 0.30 Sn 0.05 )O 3 (symbolized BBiTZS) were prepared by high-temperature solid-state reaction. The room X-ray diffraction pattern suggests a cubic perovskite structure. The thermal variation of the permittivity at different frequencies showed a relaxor ferroelectric behavior. The Raman spectroscopy was in accordance of the dielectric measurements. The diffuse phase transition parameters were determined from the modified Curie–Weiss law, while the relaxor behavior was highlighted by a good fit to the Vogel–Filcher relationship. The capacitance-potential ( C sc −2 − E ) graph at pH ∼ 7 is characteristic of n -type behavior with a flat band potential ( E fb ) of −0.52 V SCE and an electron density ( N A ) of 2.7 × 10 18 cm −3 . The Electrochemical Impedance Spectroscopy, measured in the region (1 mHz - 10 5 Hz), showed a semicircle, assigned with the bulk property (27 kΩ cm 2 ); a constant phase element (CPE) is responsible for the depletion angle (−9°). With an optical of 2.00 eV, the ferroelectric BBiTZS possesses appealing photocatalytic capability and was successfully experimented for the oxidation of Rhodamine B (Rh B) exposed to solar light. According to the band diagram, electrons from the conduction band of BBiTZS are injected into dissolved oxygen, resulting in O 2 radicals, which are employed in the Rh B oxidation. UV–Visible spectrophotometry was used to follow the Rh B discoloration. On a solar irradiation of 97 mW cm −2 , a conversion of 50% is achieved in Rh B solution (10 mg L −1 ) within 100 min., and the degradation follows a first order kinetic model with a half photocatalytic-life of 90 min.

Sintering Aid‐Assisted Growth of 0.95(K0.5Na0.5)NbO3–0.05(Bi0.5Na0.5)(Zr0.85Sn0.15)O3 Single Crystals by the Solid‐State Crystal Growth Method and Their Characterization

In this work, 0.95(K0.5Na0.5)NbO3–0.05(Bi0.5Na0.5)(Zr0.85Sn0.15)O3 (KNN–BNZS) lead‐free piezoelectric single crystals are grown by the solid‐state crystal growth (SSCG) method and their phase transitions and properties characterized. Addition of an appropriate amount of Li2CO3 and Bi2O3 sintering aids considerably promotes single‐crystal growth. Chemical composition of the single crystal is similar to the nominal composition with a slight deficiency in Na and K as evaluated by electron probe microanalysis (EPMA). X‐Ray diffraction (XRD), electrical property measurements, and temperature‐controlled Raman scattering reveal that the phase transition near room temperature is from a rhombohedral to an orthorhombic or tetragonal phase. Wide temperature range Raman scattering and dielectric properties consistently indicate transitions associated with the phase transformations or boundaries of a phase coexistence region and further details. Nontrivial frequency dependence of dielectric properties is successfully parameterized by capacitance relaxations described by Debye and Cole–Cole responses with special constant phase elements with fixed exponents of 0.5 (Warburg elements). High‐frequency dielectric constants and additional dielectric relaxations and dc relaxations are deconvoluted. The modeling parameters indicate the phase transition temperatures (or boundaries of the phase coexistence region) unambiguously. Polarization–electric field and bipolar strain–electric field hysteresis loops show that the single crystal is a classic lossy ferroelectric material.

Reverse bias dependent impedance and dielectric properties of Al/n-NC FeSi2/p-Si/Pd heterostructures formed by facing-targets sputtering

Al/n-NC FeSi2/p-Si/Pd heterostructures were formed by facing-targets sputtering. From the dark J-V results, the device showed rectifying action with leakage current. In this work, impedance spectroscopy was employed to study the electrochemical characteristics of the heterostructures, which were inspected within a frequency (f) range from 20 Hz to 2 MHz. The range of the biased voltage (V) was −1 V to 0 V. All plots of real and imaginary impedances possessed single semi-circular arcs for all bias V values. The relaxation time was 2.00 μs at −1 V, and it became faster at 0 V with 0.42 μs. The equivalent circuit for the heterostructures consisted of series resistance (Rs) combined with three sets of shunt circuits of resistance (Rp) and a constant phase element (CPE), representing grain, grain boundary, and junction, respectively. The simulated Rs and Rp values decreased, while all CPE values increased as the biased V increased. For the dielectric properties, the real permittivity (ε′) values of 86.70 at 0 V and 20.22 at −1 V were disclosed at 100 Hz; all ε′ values decreased as the f value was increased. The loss tangent revealed to be very high due to dielectric loss being much higher than ε′ values, indicating the device to be leaky. The alternating conductivities plotted against f started at a low level in low f zones and grew exponentially when f reached higher values for all V values. Direct current conductivity was observed at 1.66 × 10−4 S m−1 at 0 V, which reduced to 2.67 × 10−5 S m−1 at −1 V. The dimensionless exponent of the conductivity results was higher than 1, indicating the hopping movement within the local site.

EIS and relaxation times study for CO adsorbed on bimetallic Pt-Mo catalysts during the methanol oxidation reaction

Both Pt/C and PtMo/C catalysts were synthesized by Platinum and Molybdenum phases with Vulcan Carbon as support. The behavior of Pt-based catalysts in electrolytic media was analyzed and its Electrochemical Impedance Spectroscopy (EIS) was fitted as electric circuits to elucidate mechanisms such as adsorption, desorption and oxidation that developed during the methanol oxidation reaction through Direct Methanol Fuel Cells (DMFC). Special attention was paid to the carbon monoxide oxidation reaction on the catalyst surfaces to detect the CO poisoning effect. EIS data were used to propose the modified Randles electric circuits, which consisted of a Constant Phase Element (CPE) connected in parallel with the series of Charge Transfer Resistance (RCT) and a Finite Diffusion Warburg Element (ZW), aimed at identifying the mass transfer process. Distribution of Relaxation Times analysis (DRT) was estimated to identify other characteristics of the individual processes for both catalysts and to detect the poisoning effect of the species adsorbed on the catalyst surface.

Transport Mechanisms and Dielectric Features of Mg-Doped ZnO Nanocrystals for Device Applications.

Magnesium-doped zinc oxide “ZnO:Mg” nanocrystals (NCs) were fabricated using a sol gel method. The Mg concentration impact on the structural, morphological, electrical, and dielectric characteristics of ZnO:Mg NCs were inspected. X-ray diffraction (XRD) patterns display the hexagonal wurtzite structure without any additional phase. TEM images revealed the nanometric size of the particles with a spherical-like shape. The electrical conductivity of the ZnO NCs, thermally activated, was found to be dependent on the Mg content. The impedance spectra were represented via a corresponding circuit formed by a resistor and constant phase element (CPE). A non-Debye type relaxation was located through the analyses of the complex impedance. The conductivity diminished with the incorporation of the Mg element. The AC conductivity is reduced by raising the temperature. Its plot obeys the Arrhenius law demonstrating a single activation energy during the conduction process. The complex impedance highlighted the existence of a Debye-type dielectric dispersion. The various ZnO:Mg samples demonstrate high values of dielectric constant with small dielectric losses for both medium and high-frequency regions. Interestingly, the Mg doping with 3% content exhibits colossal dielectric constant (more than 2 × 104) over wide temperature and frequency ranges, with Debye-like relaxation. The study of the electrical modulus versus the frequency and at different temperatures confirms the non-Debye relaxation. The obtained results reveal the importance of the ZnO:Mg NCs for device applications. This encourages their application in energy storage.

Investigation of the distribution of relaxation times of a porous electrode using a physics-based impedance model

Recently, the analysis of the distribution of relaxation times (DRT) has drawn wide attention in battery engineering due to its nondestructive nature and the ability to separate the electrochemical processes with different time constants. Since proposed, the DRT is only interpreted using the equivalent circuit model (ECM), and an interpretation based on physicochemical model is still missing. To characterize the cell parameters and extract the valuable information more effectively, a new theory is developed based on the deep understanding of the physics-based impedance model and the DRT method. Particularly, a closed-form analytical expression for the DRT spectrum is derived, therefore the DRT spectrum can be explained and interpreted with a clear physical meaning. In addition, it is found that the relaxation time dispersion of EIS may have multiple origins: the porous structure of the electrode, the regularization technique used to calculate the DRT and the constant phase element type behavior of the active material particles. Based on the theory developed in this work, an optimized data analysis framework is created to better interpret the DRT spectrum. Finally, the developed DRT analysis framework is applied to the impedance data of a commercial LIB to demonstrate its advantages and effectiveness.

The kinetics of cathodic hydrogen evolution on titanium disilicide in a sulphuric acid solution

The kinetics and mechanism of hydrogen evolution reaction on the TiSi2 electrode in x M H2SO4 + (0.5 – x) M Na2SO4 (x = 0.5; 0.35; 0.20; 0.05) solutions were studied using the methods of polarisation and impedance measurements. The cathodic polarisation curves of TiSi2 were characterised by a Tafel section with a slope of 0.116–0.120 V at E ranging from –0.30 to –0.48 V (SHE). The value of hydrogen evolution overpotential at i = 1 A/cm2 for TiSi2 was 0.90–0.96 V. The kinetic parameters of the hydrogen evolution reaction on silicide were close to the theoretical values for the slow stage of charge transfer. Based on the measurements of the differential capacitance of the TiSi2 electrode (at f = 10 kHz), depending on the cathodic polarisation and acidity of the electrolyte, it was concluded that a thin dielectric film of silicon dioxide (Si + 2H2O →SiO2 + 4H+ + 4e–) was present on the surface of the silicide. The film was not reduced with low cathodic polarisations. The impedance spectra of the TiSi2 electrode at the potentials of the Tafel region were capacitive semicircles with a misplaced centre. The impedance spectra were described by an equivalent electrical circuit, the Faraday impedance of which consisted of a series-connected charge transfer resistance R1 and a parallel R2C2 chain corresponding to the adsorption of atomic hydrogen on the electrode surface. The impedance of the double layer capacitance was modelled using the constant phase element CPE1. The χ2 criterion for the circuit was (1.3-3.7)·10-4 (when using data modulus weighting), the sum of square deviations was (1.5–4.1)·10–2, and the error in the determination of the values of circuit parameters did not exceed 10 %.The experimental values of the slopes of lg R1,E-, lg R2,E-, and lg C2,E-dependences were close to the theoretical values of the slopes for the discharge-electrochemical desorption mechanism, in which both stages were irreversible and the transfer coefficients of the stages were not equal, when the Langmuir isotherm for adsorbed atomic hydrogen was fulfilled. The reaction of absorption of hydrogen with the kinetic control proceeded at the same time as the hydrogen evolution reaction.

Insights into the optical and electrochemical features of CuAl2O4 nanoparticles and it use for methyl violet oxidation under sunlight exposure

Herein, the synthesis, optical, and electrochemical characteristics of the spinel CuAl2O4 synthesized by co-precipitation are the focus of this research. As per to the X-ray diffraction (XRD), the obtained sample crystallizes in a cubic symmetry (SG: fd-3m) with a lattice constant of 8.0790 Å. The TEM image revealed spherical nanoparticles with an average build of ∼9 nm and d-spacing of 0.248 nm of the reticular the planes (3 1 1), suggesting the formation of the CuAl2O4 crystalline structure. The optical and dielectric constants, including the extinction coefficient (k), refractive index n (λ), optical conductivity (σopt), dissipation factor (tan δ) and relaxation time (τ) were determined based on diffuse reflectance. The (C−2 - E) graph, plotted in Na2SO4 showed that CuAl2O4, is feature of n-type conduct with a flat band potential of 0.42 VRHE. The EIS spectroscopy displays a semicircle feature with the presence of a constant phase element (CPE) and a bulk resistance of 558 Ω cm2 that lowers to 462.7 Ω cm2 under visible irradiation. As application, the catalytic performance of CuAl2O4 was examined in the breakdown of Methyl violet dye (MV) under sunlight. Within 3 h, an abatement of 89% was obtained, and the oxidation of MV (10 mg/L) follows a first-order kinetic model with a half-life of 82 min. The catalyst can be reused without loss of activity for the first four cycles where •OH and •O2− are accountable of the MV oxidation.

Experimental observation of ohmic impedance

Impedance spectroscopy measurements are often confounded by electrode-geometry-induced high-frequency phenomena associated with a frequency-dependent complex ohmic impedance. The ohmic impedance was obtained by Levenberg-Marquardt regression of a process model that used the Havriliak-Negami equation to account for the ohmic impedance. Experimental results obtained for the ferri/ferrocyanide redox species on a gold disk used as a model system were interpreted using a physical description expressed in terms of an ohmic impedance and an expression that accounted for the influence of a local constant-phase element on the faradaic reaction and the convective diffusion impedance. Regressions were weighted by the experimentally determined error structure of the data, and the resulting parameters characteristic of the ohmic impedance were in excellent agreement with numerical simulations.

Activated carbons prepared from hazelnut shell waste by phosphoric acid activation for supercapacitor electrode applications and comprehensive electrochemical analysis

In this study, the activated carbon was produced from hazelnut-shell wastes using a single-step chemical activation. The activated carbon with a specific surface area of 1363 m2 g−1 and micropore volume of 0.52 cm3 g−1 was used to synthesize magnetic activated carbon to investigate the influence of the magnetization on the capacitive performance. The porous carbon samples were characterized using various techniques and analyses including N2 adsorption-desorption isotherms, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, Raman, and vibrating sample magnetometer. The prepared electrodes were evaluated by cyclic voltammetry, galvanostatic charge-discharge, and electrochemical impedance spectroscopy. The specific capacitance values of the activated carbon electrode and magnetic-activated carbon electrode were 247.8 F g−1 and 76.23 F g−1 at 0.75 A g−1, respectively. Moreover, the impedance responses were mathematically modeled using an equivalent electric circuit. Although a more homogeneous current distribution was obtained for the magnetic activated carbon, the higher constant phase element coefficient of the activated carbon demonstrated a higher capability of adsorption of mobile ions. The results showed the higher capacitive performance of the activated carbon electrodes for energy applications.

Impedimetric Chemosensing of Volatile Organic Compounds Released from Li-Ion Batteries.

Detection of toxic and flammable gases and volatile organic compounds (VOCs) released from Li-ion batteries during thermal runaway can generate an early warning. A submicron (∼0.15 μm)-thick poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) sensor film is coated on a platinum electrode through a facile aqueous dispersion. The resulting sensor reliably detected different volatile organic compounds (VOCs) released during the early stages of thermal runaway of lithium-ion batteries (LIBs) even at low concentrations. The single-electrode sensor utilizes impedance spectroscopy to measure ethyl methyl carbonate and methyl formate concentrations at 5, 15, and 30 ppm independently and in various combinations using ethanol as a reference. In contrast to DC resistance measurement, which provides a single parameter, impedance spectroscopy provides a wealth of information, including impedance and phase angle at multiple frequencies as well as fitted charge transfer resistance and constant-phase elements. Different analytes influence the measurement of different parameters to varying degrees, enabling distinction using a single sensing material. The response time for ethyl methyl carbonate was measured to be 6 s. Three principal components (PCs) preserve more than 95% of information and efficiently enable discrimination of different classes of analytes. Application of low-power PEDOT:PSS-based gas sensors will facilitate cost-effective early detection of VOCs and provide early warning to battery management systems (BMS), potentially mitigating catastrophic thermal runaway events.

Tuning the electrical properties of colloidal nanoalloys by varying their composition

Colloidal nanoalloys have been shown to have combined advantageous properties of their metallic constituents. However, the research on the electrical properties of colloidal nanoalloys is still lacking. We report an electrical properties study of gold-silver nanoalloys of various compositions suspended in Milli-Q water using impedance spectroscopy. We model the impedance spectra with an equivalent electrical circuit that consists of a constant phase element (CPE) in series with a parallel of a resistor and a capacitor. Through this model, we can extract information about the conductivity, relative permittivity, and electrode/solution interface properties of the colloidal nanoalloys. We have found that the conductivity and relative permittivity increase almost linearly with the increase of gold molar fraction in the solution. This means that the electrical properties of colloidal nanoalloys can be easily tuned by varying their composition. A possible direct application of these findings is for tailoring nanoparticles as contrast agents in applications such as electrical impedance tomography.

Analysis of failure causes of epoxy-phenolic coated tinplate after boiling sterilization

This work aimed to study the “blushing” phenomenon occurring on epoxy-phenolic coated tinplate after boiling sterilization at 127 ℃ for 1 h. The corrosion resistance of the “blushing” coating and intact coating were measured in NaCl solutions. The possible failure causes were investigated by electrochemical impedance spectroscopy (EIS) combined with surface and cross-section morphology analyses. Electrochemical equivalent circuit (EEC) analyses revealed that, the coating resistance of the “whitening” sample was ∼ 6 times lower than the intact sample, while the charge transfer resistance at the tinplate/coating interface of the “whitening” sample was ∼ 10 times lower than the intact sample. The capacitance arc at low frequency range showed a constant phase element (CPE) behavior (a time constant dispersion at the tinplate/coating interface), which was due to the material composition inhomogeneity at that interface. Severe underfilm corrosion and coating disbondment were observed on the “whitening” sample after immersing into NaCl solution for 3d, which was due to the poor anticorrosion resistance of the epoxy-phenolic coating and poor coating adhesion. Thin thickness, poor adhesion and disbondment led to a “white” appearance after boiling sterilization.

Electrochemical behaviour of LiCl-KCl eutectic melts containing moisture as impurity. Part II: Uranium electrode

In Part I, LiCl-KCl eutectic melt purified by chlorine and LiCl-KCl + xwt.% H2O prepared by thermal equilibration of eutectic mixture with H2O at 500 °C were analysed for moisture content using acid-base titration. They were further investigated by electrochemical impedance spectroscopy (EIS) at inert tungsten electrode. It was established that cathodic reduction of H2O led to formation of OH- that adsorbed on tungsten electrode in potential range −0.80 to −1.50 V. The OH- film contributed to capacitive response as well as it offered a resistance to any other faradaic process occurring in that potential range. In this work, same LiCl-KCl eutectic melts were used to explore the anodic dissolution of uranium electrode in potential range −1.40 to −0.90 V by EIS. Complex impedance data in all melts were fitted to different equivalent circuit models. Presence of OH- film, which influenced the dissolution of uranium in LiCl-KCl + H2O melts, was modelled using additional resistor and constant phase elements in the equivalent circuit. Impedance data were further validated by Kramers-Kronig transforms where pseudo-χ2 values varied from 8.5×10−6 to 1.2×10−4 confirming a good compliance with spread of fit residuals across logω limited to less than ±3%. After EIS measurements, melts were again analysed by cyclic voltammetry and additional voltammetric features complicating the redox behaviour of U3+|U couple were analyzed.