Electrochemical Impedance Spectroscopy (EIS) is a powerful non-invasive technique used to characterize Lithium-ion cells. Its application allows to identify and track the evolutions of cell degradation processes within a short testing time. This review collects all the available works which have used EIS spectra either to characterize Li-ion cell degradation or to develop Electric Circuit Models (ECMs). The objectives of this work are: (i) to highlight the influence of different aging test conditions on the EIS spectra; (ii) to find the correlations between EIS spectra variations and the underlying degradation mechanisms and (iii) to list the available options to formulate ECMs from EIS spectra of aged cells. After an exhaustive analysis of the state-of-the-art, a critical review is presented to discuss the existing links between degradation mechanisms and the most reliable solutions to model them.

The present study aims at deposition of zinc phosphate coatings with the incorporation of nano Titanium dioxide particles by chemical phosphating method. Zinc phosphate coatings were developed on low carbon steel by using nano TiO2 in the standard phosphating bath. The Coated low carbon steel samples were assessed for corrosion studies using electrochemical impedance spectroscopy and potentiodynamic polarisation techniques in 3.5% NaCl solution. Chemical composition of the coatings was analysed by energy dispersive X-ray spectroscopy (EDX). Significant variations in the coating weight, porosity and corrosion resistance were observed with the addition of nano TiO2 in the phosphating bath. Corrosion rate of nano TiO2 incorporated chemical phosphate coated samples was found to be 3.5 mpy which was 4 times less than the bare uncoated low carbon steel (~14 mpy). Electrochemical impedance spectroscopy studies revels in the reduction of porosity in nano TiO2 phosphate coated samples. It was found that nano TiO2 particles in the phosphating solution yielded phosphate coatings of higher coating weight, greater surface coverage and enhanced corrosion resistance than the normal zinc phosphate coatings (developed using normal phosphating bath).

The electrical percolation of alternating current through two-phase polyethylene/graphite composite electrodes with different contents of graphite microparticles immersed in aqueous KCl solutions has been studied. Above the graphite content of the first percolation threshold, the electrochemical impedance response of this electrode is associated with an equivalent circuit of resistance Ru in series with a constant phase element CPE. An insulator material+conductive filler model is proposed in which the electroactive surface is considered as the intersection of the percolation cluster through the solid and the cluster associated with the interfacial region. CPE is analyzed assuming a distribution of micro-capacitors of the graphite particles in contact with the dielectric solution and inside the dielectric polymeric phase.

Featured Application: Bio-electronic devices take advantages of some specific duties of biological matter. The specific ability of some proteins to use sunlight is considered for the realization of photo-electronic devices . Here the focus is on the role of the pH, whose variations seem to affect the protein conductance

1-[(4-ethyl-2-phenyl-4,5-dihydro-1,3-oxazol-4-yl)methyl]-4-phenyl-1H-1,2,3-triazole (Ph4) and1-[(4-ethyl-2-phenyl-4,5-dihydro-1,3-oxazol-4-yl)methyl]-5-phenyl-1H-1,2,3-triazole (Ph5) are new isomers of the triazole derivative family, were synthesized and tested on the corrosion of mild steel in molar hydrochloric acid molar media using weight loss, electrochemical polarization and impedance spectroscopy. Then the experimental results were confirmed by quantum chemical calculations using DFT at B3LYP /6-31G (d,p). The compound Ph4 is the best inhibitor and its inhibitory efficiency increased with increasing concentration and reaching 95% at 10⁻³ M. Polarization curves studies show that both compounds tested are mixed-type inhibitors. Nyquist curves presented a single capacitive loop, their diameter increases progressively with both inhibitors concentration. The change of the substitution phenyl from position 5 to position 4 in the triazole ring increases the inhibitory effect of the triazole compounds. The effect of temperature on the corrosion behavior of iron indicates that the inhibitory efficiency of the two inhibitors decreases with increasing temperature in the range of 308 to 338K. DFT study is in good correlationwith the experimental results.

A novel manufacturing process is presented for producing Nano powders and thin films of CuCoO₂ (CCO) material. This process utilizes three cost-effective synthesis methods: hydrothermal, sol-gel, and solid-state reactions. The resulting delafossite CuCoO₂ samples were deposited onto transparent substrates through spray pyrolysis, forming innovative thin films with a Nano crystal powder structure. Prior to the transformation into thin films, CuCoO₂ powder was first produced using a low-cost approach. The precursors for both powders and thin films were deposited onto glass surfaces using a spray pyrolysis process, and their characteristics were examined through X-ray diffraction, scanning electron microscopy, HR-TEM, UV-visible, and Electrochemical impedance spectroscopy (EIS) analyses was conducted to determine the conductivity in transversal direction of this groundbreaking material for solar cell applications. On the other hand, the sheet resistance of the samples was investigated using the four probe-method to obtain the sheet resistivity and them calculate the in plane conductivity of the samples. We also investigated the aging characteristics of different precursors with varying durations. The functional properties of CuCoO2 samples were explored by studying chelating agent and precursor solution aging periods. Resuming, this study thoroughly discusses the synthesis of delafossite powders and their conversion into thin films, which hold potential as hole transport layers in transparent optoelectronic devices.

This work aims to follow the corrosion behavior of copper in 3 wt% NaCl solution in the presence of a bio-oily extract. Spent coffee grounds (SCG), a highly recyclable and usable biomass - often thrown away and becoming a serious threat to the environment - , has a fraction of oils (12%) that we have opted to use as a corrosion inhibitor for copper. The extraction was carried out using n-hexane as the solvent for the decoction. The oily fraction was analyzed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Potentiodynamic polarization measurements have revealed SCG extract acts as a cathode-type inhibitor for copper in saline media, mainly preventing the diffusion of oxygen molecules toward the substrate. As the extract concentration increased, the inhibition efficiency has improved as well, reaching 95.78 % with 0.6 g/L of SCG extract. The obtained results by electrochemical impedance spectroscopy (EIS) are in accordance with the order of inhibitory efficiency obtained by potentiodynamic polarization. We have found that the SCG extract adsorption process on copper surface is spontaneous and complies with Langmuir isotherm.

To achieve a fast testing on barrier properties of organic coatings, immersion test, AC-DC-AC test, and coupled test of AC-DC-AC with hydrostatic pressure were conducted in seawater for a glass flake epoxy coating. Electrochemical impedance spectroscopy (EIS) was used to characterize the degradation processes of the coating during the tests, and the surface of the coating was analyzed using optical microscope, scanning electron microscope (SEM) and Fourier transform infrared spectrometer (FTIR). The results show that the periodically cathodic polarization coupled with high hydrostatic pressure can accelerate the degradation of the coating by facilitating the diffusion and uptake of electrolyte and the delamination of the coating. The coupled test method has the largest acceleration due to the synergetic effect of AC-DC-AC and hydrostatic pressure.

The aims of this work were to examine the new electrode, based on polymer bacteria modified aluminum electrode for simultaneous production of electricity and degradation of phenol. This electrode is based aluminum modified by bacteria inserted in the polymer matrix, developed in situ on the surface. This electrode, designated subsequently by bacteria-polymer-aluminum, Showed stable response and was characterized with voltametric methods, as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The experimental results revealed that the prepared electrode could be a feasible for degradation of hazardous phenol pollutants. The sensor was successfully applied to the determination of phenol in a real sample with satisfactory results.

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In recent years extensive studies have been continuously undertaken on the design of bioactive and biomimetic dental implant surfaces due to the need for improvement of the implant-bone interface properties. In this paper, the titanium dental implant surface was modified by a bioactive vitamin D3 coating prepared by self-assembly process. Surface characterization of the modified implant was performed by field emission scanning electron microscopy (FE-SEM), attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), and contact angle measurements (CA). Implant’s electrochemical stability during exposure to an artificial saliva solution was monitored in situ by electrochemical impedance spectroscopy (EIS). Experimental results obtained were corroborated by means of quantum chemical calculations at the density functional theory level (DFT). The formation mechanism of the coating onto the titanium implant surface was proposed. During a prolonged immersion period, the bioactive vitamin D3 coating effectively prevented the underlying titanium from corrosive attack (polarization resistance in order of 10⁷ Ω cm²) with ~95% protection effectiveness.

In this work, unmodified screen-printed electrode (bare SPE) and Sb-film modified SPE (SbFSPE) sensors were employed for the analysis of trace amounts of Pb(II) in non-deaerated water solutions. The modified electrode was performed in situ in 0.5 mg/L Sb(III) and 0.01 M HCl. The methodology was validated for an accumulation potential of –1.1 V vs. Ag/AgCl and an accumulation time of 60 s. A comparative analysis of bare SPE and SbFSPE showed that the detection and quantification limits decrease for the bare SPE. The method with the bare SPE showed a linear response in the 69.8–368.4 µg/L concentration range, whereas linearity for the SbFSPE was in the 24.0–319.1 µg/L concentration range. This work also reports the reason why the multiple standard addition method instead of a linear calibration curve for Pb(II) analysis should be employed. Furthermore, the analytical method employing SbFSPE was found to be more accurate and precise compared to the use of bare SPE when sensors were employed for the first time, however this performance changed significantly when these sensors were reused in the same manner. Furthermore, electrochemical impedance spectroscopy was used for the first time to analyse the electrochemical response of sensors after being used for multiple successive analyses. Surface characterisation before and after multiple successive uses of bare SPE and SbFSPE sensors, with atomic force microscopy and field emission scanning electron microscopy, showed sensor degradation. The interference effect of Cd(II), Zn(II), As(III), Fe(II), Na(I), K(I), Ca(II), Mg(II), NO₃^– Bi(III), Cu(II), Sn(II), and Hg(II) on the Pb(II) stripping signal was also studied. Finally, the application of SbFSPE was tested on a real water sample (from a local river), which showed high precision (RSD = 8.1%, n = 5) and accurate results.

The performance of modified electrode of nanocomposite film consisting of polypyrrole-chitosan-titanium dioxide (Ppy-CS-TiO2) has been explored as non-enzymatic glucose biosensors. The synergy effect of TiO2 nanoparticles and conducting polymer on the current response of electrode resulted in higher sensitivity for nanocomposite modified electrode. The incorporation of TiO2 nanoparticles in the nanocomposite films were confirmed by XPS spectra. The FESEM and HR-TEM provided more evidences for the presence of TiO2 in Ppy-CS structure. Glucose biosensing properties were determined by amperommetry and cyclic voltammetry (CV) methods. The interfacial properties of nanocomposite electrodes were studied by electrochemical impedance spectroscopy (EIS). The developed biosensors showed a good sensitivity over the liner range of 1-14 mM with a detection limit of 614 μM for glucose. It also exhibited good selectivity and long term stability with no interference effect. The Ppy-CS-TiO2 nanocomposites film presented high electron transfer kinetics.

Food pathogens contaminate food products that allow their growth on the shelf and also under refrigerated conditions. Therefore, it is of utmost importance to lower the limit of detection (LOD) of the method used and to obtain the results within hours to few days. Biosensor methods exploit the available technologies to individuate and provide an approximate quantification of the bacteria present in a sample. The main bottleneck of these methods depend on the aspecific binding to the surfaces and on a change in sensitivity when bacteria are in a complex food matrix in respect to bacteria in a liquid food sample. In this review we introduce Surface Plasmon Resonance (SPR), new advancements in SPR techniques, and Electrochemical Impedance Spectroscopy (EIS), as label-free biosensing technologies for the detection of L. monocytogenes in foods. The application of the two methods has made possible the detection of L. monocytogenes with LOD of 1 log CFU/mL. Further advancement are envisaged through the combination of biosensor methods with immunoseparation of bacteria from larger volumes.

In this work, electrochemical deposition (galvanostatic and potentiostatic) techniques were used to obtain of new composite polymer: 3-methylpyrrole - sodium dodecyl sulfate/poly 2-methythiophene (P3MPY-SDS/P2MT) coatings on cobalt -based alloy sample for anticorrosion protection. The sodium dodecyl sulfate as a dopant ion used in electropolymerization practice can have a relevant effect at the anticorrosion protection of the composite polymer layer by blocking the entry of aggressive ions. The cobalt -based alloy substrate had an important influence on the electrochemical performance of the composite coating and this together with the presence of the polymeric layer was achieved by simultaneously formation of a complex oxides film and polymeric layers. The polymeric coatings were analyzed by cyclic voltammetry, Fourier transform infrared (FT-IR) spectroscopy and scanning electron microscopy (SEM) methods. The corrosion protection of P3MPY-SDS/P2MT coated cobalt based alloy has been explored by potentiostatic and potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) procedures in1 M HCl medium. The corrosion establishment of P3MPY-SDS/P2MT covered cobalt based alloy was observed to be ~10 times less than that uncoated specimen and the effectiveness of these composite layers of this coating is above than 90%. The superior efficacy is achieved by the electrochemical polymerization of P3MPY-SDS/P2MT obtained at 0.5 mA/cm2 and 1mA/cm2 current densities and at 0.9V and 1.0V potential applied and in molar ratio 5:1. Corrosion tests result indicated that P3MPY-SDS/P2MT coatings provide good corrosion protection of cobalt -based alloy in aggressive environments.

A new approach to fabricate TiNi surfaces combining the advantages of both monolithic and porous materials for implants is used in this work. New materials were obtained by depositing a porous TiNi powder onto monolithic TiNi plates followed by sintering at 1200°C. Then, further modification of the material surface with a high-current-pulsed electron beam (HCPEB) was carried out. Three materials obtained (one after sintering and two after subsequent beam treatment by 20 and 30 pulses, respectively) were studied by XRD, SEM, EDX, EIS methods, profilometry and OCP measurements. Structural and compositional changes caused by HCPEB treatment were investigated. Surface properties of the samples during their storage in saline for 10 days were studied and a model experiment with cell growth (MCF-7) was carried out for the sample unmodified with electron beam to detect cell appearance on different surface locations.

Premature failure and degradation of layers are the main problems for transportation infrastruc-ture. Addressing these issues necessitates implementing structural health monitoring (SHM) for transportation layers. This strategic approach is instrumental in mitigating maintenance expenses, prolonging the operational lifespan, and preventing accidents resulting from abrupt layer col-lapse. To this end, this research investigated the stress/strain and damage detection capabilities of a self-sensing cementitious composite developed for potential utilization in the construction of an intelligent subgrade layer. The prepared self-sensing cementitious composite consisted of 10% cement and hybrid conductive fillers, including multiwalled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) in sand. Initial findings reveal that the electrical resistivity of the composite is significantly affected by the concentration of MWCNTs/GNPs, with a minimum concentration of more than 0.5% needed to achieve a responsive cementitious composite. More-over, the piezoresistive analysis indicates that an increase in the concentration of MWCNTs/GNPs and stress levels leads to an improvement in the stress/strain sensing perfor-mance. When the self-sensing cementitious composite is subjected to equivalent stress levels, variations in the FCR exhibit an increasing trend with decreasing resilient modulus, stemming from a decrease in stiffness due to the increased concentration of MWCNTs/GNPs. Additionally, the EIS analysis demonstrates a contraction for the Nyquist curves under compressive ramp loading prior to failure, followed by the expansion of these curves postfailure. Scanning electron microscopy (SEM) images visually showcase the bridging effects of MWCNTs and the filling ef-fects of GNPs within the composite structure.

Retired Electric vehicles (EVs) batteries are reused in second life energy storage applications. However, the overall performance of repurposed energy storage system (ESS) is limited by the unevenness of individual batteries use in it. Therefore, battery grading is required for optimal performance of ESS. Electrochemical impedance spectroscopy (EIS) based evaluation of battery aging is a promising way to grade lithium-ion batteries. However, it is not practical to measure impedance of mass retired batteries due to high complexity and slowness. In this paper, a broadband multi-sine binary signal (MSBS) perturbation integrated with multichannel EIS system is presented to measure impedance spectra for high-speed aging evaluation of lithium-ion batteries or modules. The measurement speed is multi-times higher than conventional EIS with single-channel configuration. The broadband MSBS is validated with reference sinusoidal sweep perturbation and corresponding root-mean-square error (RMSE) analysis is performed. Moreover, the accuracy of the presented multichannel EIS system is validated by impedance spectra measurement of Samsung INR18650-29E batteries and comparing it with those measured with commercial EIS instrument. A chi-squared error under 0.641% is obtained for all 8-channels. Since the non-linearity of battery has significant impact on quality of impedance spectra. Therefore, Kronig-Kramer (KK) transform validation is also performed.

This paper presents three approaches to estimating battery parameters of the electrical equivalent circuit model (ECM) based on electrochemical impedance spectroscopy (EIS); these approaches are referred to as (a) least squares (LS), (b) exhaustive search (ES), and (c) nonlinear least squares (NLS). The ES approach is assisted with the LS method for the rough determination of the lower and upper bound of the ECM parameters, and the NLS approach is incorporated with the Monte Carlo run such that different initial guesses can be assigned to improve the goodness of EIS fitting. The proposed approaches are validated using both simulated and real EIS data. Compared to LS approach, the ES and NLS approaches show better fitting accuracy at various noise levels; whereas both in the validation using simulated EIS data and actual EIS data collected from LG 18650 and Molicel 21700 batteries, the NLS approach shows better fitting accuracy than that of LS and ES approaches. In all cases, compared with the ES approach, the computational time of the NLS approach is significantly faster, and compared with the LS approach, the NLS approach shows a minimal difference in computational time and considerably better fitting performance.