AC Impedance Analysis Research Articles

Electrical characteristics of (AgNPs-PVA)-based Schottky diode and its application as a low-voltage varistor devices

In this report, we studied the influence of silver nanoparticles (AgNPs) on the electrical conductivity of Polyvinyl Alcohol (PVA) as a semiconductor nanocomposites active layer. Here, the Schottky junction is constructed by mechanically pressing a copper (Cu) electrode onto a AgNPs-PVA nanocomposite, which shows rectification behavior at room temperature. The synthesis of silver nanoparticles (AgNPs) was achieved by the physical reduction of silver nitrate using an ultraviolet lamp. The nanocomposite films were created using a casting technique. An ultraviolet spectrophotometer (UV–vis), which displayed maximum absorbance at 430 nm, was used to confirm the synthesis of AgNPs and carry out the optical band gap. The charge carrier transport properties of AgNPs-PVA film were investigated by using impedance spectroscopy and I–V measurements. Then, AC impedance analysis was used to determine grain and grain boundary resistances; current-voltage analysis enabled the barrier height (Φ) to be determined. Moreover, the metal/semiconductor (Cu/AgNPs-PVA) Schottky barrier was confirmed as an equivalent circuit model via the Nyquist plot. Based on thermoionic emission theory, the characteristic I–V induced rectifying Schottky behavior can be understood. Moreover, the AgNPs-PVA nanocomposite exhibited hysteresis behavior under multiple repetitive measurements. For low voltage varistor devices, the nonlinear behavior may be completely utilized.

Study of structural, optical, photocatalytic, electromagnetic, and biological properties Co0.75Mg0.25CexFe2−xO4 of Mg-Co nano ferrites

Nano spinel ferrites with formula Co0.75Mg0.25CexFe2−xO4 (0 ≤ x ≤ 0.25 by step 0.05) were synthesized by using citrate gel auto combustion method and studied their structural characterization, optical studies, photocatalytic, biological and electromagnetic properties. Structural properties carried out by XRD, SEM, EDS, FTIR spectroscopy. The XRD studies confirm the crystalline size & lattice constant of Ce co-doped Co-Mg mixed nano ferrites. Morphology of the samples were examined by SEM and EDS analysis confirmed the proposed sample composition. FTIR spectral analysis help to confirm the formation of spinel structure in ferrite samples. Further optical studies confirm the band gap energy and cut off wavelength. Photocatalytic degradation of MB and AR dyes were carried out and good results were observed the degradation activity due to the catalyst heat treatment. Antibacterial studies confirmed that the nanoparticles are toxic to Bacillus subtilis, staphylococcus aureus (gram-positive strains) and Escherichia coli, Klebsiella pneumonia (gram-negative strains) Bacillus subtilis showed highest zone of inhibition of 13.3 mm. Saturation magnetization, coercivity, and remanence magnetization were calculated by VSM and Co0.75Mg0.25Ce0.25Fe1.75O4 was found to have high saturation magnetization that indicates that the sample behaves like a super para magnet. The Squareness of Co-Mg-Ce mixed nano ferrites initially decreases than increases hence the system changes from soft ferrites to hard ferrites. The electromagnetic properties such as AC conductivity (σAC), Dielectric constant (ε/), and impedance analysis are reported. The cole–cole plots shows the single semicircle behaviour.

Sustainable Low-Temperature Coating of LATP/C Solid Electrolyte Composites on LiNi1/3Co1/3Mn1/3O2 Cathode Based on Lithium Iodide Solvent-Recrystallization for Li-Ion Batteries

A mixed ionic (Li1.3Al0.3Ti1.7(PO4)3: LATP) and electronic conductor (porous carbon: C) hybrid layer can effectively enhance the electrochemical performance of cathode materials. In this work, a sustainable low-temperature synthesis strategy (≤200 °C) combining ball milling and solvent-recrystallization of lithium iodide is first proposed to prepare the LATP/C coated LiNi1/3Co1/3Mn1/3O2 (LNCMO) material. The characterizations of structures and morphology reveal that LATP and porous carbon powder are mixed into the ethanol dissolved lithium iodide by a simple ball milling process, then the lithium iodide is recrystallized to serve as a binder when ethanol is vaporized at a low temperature to coat uniform thickness and homogeneously distributed LATP/C on the surface of LNCMO cathode. The charge-discharge results illustrate that the cycling performance and rate discharge capability of the active materials coated with LATP/C are significantly superior to the bare LNCMO. AC impedance analysis confirms that lower charge transfer resistance and higher Li+ ion diffusion coefficient are achieved in cathode materials. This work successfully exploited a novel low-temperature cathode coating method based on lithium iodide solvent-recrystallization and obtained results comparable to high-temperature processes without suffering from side reaction problems.

Structural, electrical and dielectric studies of PVA based NaNO3 Polymer electrolytes for battery applications

Polyvinyl alcohol (PVA) with different concentrations of sodium nitrate (NaNO3) is prepared by the solution cast method. These polymer electrolytes’ structural, vibrational, thermal and electrical characteristics are studied by X-ray diffraction, Fourier transforms infrared spectroscopy, Differential scanning calorimetry and AC impedance analysis. Dielectric properties, DC conductivity and AC conductivity, are studied by electrical properties. The AC conductivity for all the samples of PVA with NaNO3 is analyzed at different frequencies in the temperature range 303–373 K. Maximum conductivity is observed at room temperature for the concentration of 70% PVA with 30% NaNO3, and it is 6.69 × 10−7 S/cm. XRD studies confirmed the amorphous nature of these prepared samples. Dielectric nature of PVA: NaNO3 polymer electrolyte samples are investigated by dielectric constant (ε1) and dielectric loss (ε11). The minimum phase transition occurred at 70% PVA: 30% NaNO3. The Swagelok cell verified the discharge characteristic of the highest conductivity membrane in the operating temperature range using laboratory methods.

Enhancement of electrical and electrochemical properties of sodium bromide incorporated with poly (ethylene oxide)/poly (vinylidene fluoride-hexafluoropropylene) solid blend polymer electrolytes for electrochemical double layer capacitors

Sodium-ion conducting solid blend polymer electrolytes are prepared with Poly (ethylene oxide) (PEO)/Poly (vinylidene fluoride-hexafluoropropylene) P(VdF-HFP)/Sodium Bromide (NaBr) by solution casting technique. Different analysis such as structural, vibrational, electrical and electrochemical studies reveal promising properties of the prepared solid polymer electrolytes (SPE). The XRD analysis illustrates the increase in amorphous nature of the sample up to 8 wt% NaBr salt concentration. The complexation between polymers and salt has been examined by FTIR analysis. To examine the electrical conductivity, AC impedance analysis was performed in the temperature range of 303–373 K. The higher ionic conductivity (σ) of 1.10 × 10−3 S cm−1 was found for the solid polymer electrolyte (SPE) containing 8 wt% NaBr at room temperature. The temperature dependence of ionic conductivity resembles Arrhenius behavior. The dielectric behavior has been analyzed using dielectric permittivity (ε*) and the relaxation frequency (τ) has been calculated from the loss tangent spectra (tan δ). The modulus spectra indicate the non-Debye nature of the material. Wagner's DC polarization technique was used to compute the transference number. According to the LSV analysis, the solid blend polymer electrolytes have the suitable electrochemical potential window to be used in electrochemical devices. The cyclic voltammetry (CV) and charge-discharge studies (GCD) of the assembled electrochemical double-layer capacitor (EDLC) show specific capacitance (Csp) values of 12.9 F/g and 10.4 F/g respectively. Further the better performance of EDLC is confirmed with its energy density (3.25 to 2.12 Wh/kg), power density (750 to 2623 W/kg) as well as coulombic efficiency (98.2 %) after 1500 cycles.

Defect Characterization in Gel Phantom Using Ac Impedance Spectroscopy

Gel phantoms are useful materials for medical diagnostics and impact testing. The gel phantoms can be tailored to suit various tissues from the bulk, microscopic and molecular components. These components have responses under an AC electric field. In this work, a gel phantom was prepared using a commercially-available gel powder. Cylindrical samples with varying degrees of defects were cut from the prepared gel phantom and tested using an AC impedance analyzer. The defects were created by piercing a needle along the center plane of the sample and the degree of defects was varied by increasing the number of piercings in the sample. The conductivity of the sample at lower frequencies was influenced by the mechanism involved in water leakage due to piercing while the conductivity at higher frequencies was dominantly affected by space charge relaxation and structural conductivity barriers. The Nyquist plots obtained were seen to exhibit modified Randles-type behavior. Equivalent circuit fittings showed the parameters to be distinct with varying degrees of defects.

Triethylammonium thiocyanate ionic liquid electrolyte-based supercapacitor fabricated using coconut shell-derived electronically conducting activated charcoal electrode material

Organic solvents are commonly used as commercial electrolytes in supercapacitors, but they have several drawbacks, such as high volatility, toxicity, and environmental issues. To overcome these problems, ionic liquids are used though their high costs hamper commercial applications. In this study, a novel and low-cost ionic liquid based on triethylammonium cation and thiocyanate anion were synthesized and used as the electrolyte in a low-cost supercapacitor fabricated using electronically conducting activated carbon derived from cleaned coconut shells as electrode material. The temperature dependence of electrolyte conductivity was investigated, in the frequency range of 1 Hz-500 kHz, using AC impedance analysis, in the temperature range from 30 °C - 90 °C in ten-degree increments and found to be in the range of 4.5 to 14.4 mS cm−1. The ion transport kinetics behaves according to the Vogel-Tammann-Fulcher (VTF) model with an activation energy (Ea) and the pre-exponential factor (AσT) of 0.0158 eV and 114.9 S m−1 K1/2, respectively. The activated carbon material developed has a high porosity and high electronic conductivity. The electrode fabrication methodology was optimized by varying the polyvinylpyrrolidone (PVP) binder amount with respect to the mass of activated carbon on a titanium sheet as a function of heat treatment temperature. The supercapacitor that gives the highest specific capacitance is based on the electrode constructed using 5 % w/w PVP in 0.50 g of activated carbon deposited on a titanium sheet by heat treating at 200 °C for 20 min. At the scan rate of 5 mV s−1, two-electrode CV studies revealed a specific capacitance of 36.8 F g−1 for the optimized supercapacitor assembly. The electrolyte triethylammonium thiocyanate (TAT) demonstrated good electrochemical stability and a large operating voltage window of 1.8 V and high stability, with 94.4 % capacity retention after 1000 cycles. The AC impedance studies also gave comparable results. Prime novelty statementThe manuscript describes a method to prepare a novel and low-cost ionic liquid material triethylammoniumthiocyanate starting from triethylamine and ammonium thiocyanate, and its application as the ionic liquid electrolyte in a low-cost supercapacitor. The electrode material used in the supercapacitor was fabricated using electronically conducting activated carbon derived from cleaned coconut shells, which were deposited firmly adhering to titanium sheets using polyvinylpyrrolidone binder under optimized heat treatment conditions. As such, both the ionic liquid electrolyte and the activated carbon electrode material are novel and attractive materials for the commercial production of low-cost supercapacitors.

Ameliorating the electrode/electrolyte interface compatibility in Li-ion solid-state batteries with plasticizer

Composite solid electrolytes (CSEs) based on poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/LiTFSI/LLZO/different wt% of tetra-ethylene-glycol-dimethyl-ether (TEGDME) were prepared using the facile solution casting method or phase-inversion method. X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy measurements were used to identify the structures and complexations of the prepared electrolyte films. The morphology and thermal stability of the electrolytes were investigated using field-emission scanning electron microscopy (FE-SEM) and thermogravimetric analysis (TGA). The ionic conductivity of all electrolyte films was analyzed using AC impedance analysis between 298 and 353 K. The data supports that the 30 wt% TEGDME CSE exhibited the highest ionic conductivity (6.2 × 10–5 S cm–1 at 25 ℃ and 3.6 × 10–4 S cm–1 at 60 ℃) and a wide electrochemical window (4.87 V vs. Li/Li+). A solid-state battery with LiFePO4/Li-metal was cycled using the 0.1 C rate at 60 °C for 100 cycles, resulting in a high initial discharge capacity of 157 mAh g–1 with a good coulombic efficiency of> 99%. This admirable electrochemical performance can be attributed to the high ionic conductivity of the electrolyte and its electrochemical stability. We emphasize the significant role of the TEGDME plasticizer in the performance of the CSE as well as the ionic conductivity and compatibility of the electrolyte with the electrode in the solid-state battery. All encouraging results confirm that the CSE has the potential to be a high-voltage electrolyte for Li-ion solid-state batteries.

Effect of nano TiO2 on the thransport, structural and thermal properties of PEMA-NaI solid polymer electrolytes for energy storage devices

Nano Titania (TiO2) added polymer electrolytes have been prepared successfully via conventional solvent casting technique using Poly (Ethyl Methacrylate) (PEMA) as the host polymer and Sodium Iodide (NaI) as salt. Different characterization techniques such as AC impedance spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), and Thermogravimetric differential thermal analysis (TG-DTA) have been employed. With the help of the AC impedance analyzer, the ionic conductivity for all samples has been calculated and higher ionic conductivity of 2.91 × 10−5 Scm−1 is achieved for the system PEMA/NaI/4 wt% TiO2 at room temperature. The shifting and disappearance of bands in FTIR spectroscopy confirm the mixing of polymer and salt in the homogeneous polymer electrolytes. The decrease in crystallinity and hence the increase in amorphous nature has been confirmed through XRD studies. The diffusion coefficient, mobility, and the number of mobile ion concentrations have been estimated for all compositions of nano TiO2 added PEMA/NaI systems. The thermal stability of the membranes has been investigated by TG-DTA analysis.

Realizing oxygen ion conduction in perovskite structure NaNbO3 by A-site Bismuth doping

The perovskite structure materials used as an oxygen ion conductor in solid oxide fuel cells have been widely studied. Here, we report novel property of NaNbO3-based ceramics about oxygen ion conduction. The grain size is significantly increased as well as the structural symmetry is enhanced with bismuth doping. Based on the analysis of AC impedance in serial pO2, nearly pure oxide ions conduction characteristic was realized in Na0.4Bi0.2NbO3 composition. Remarkably, electrical conductivity of Na0.4Bi0.2NbO3 sharply increased 3 orders of magnitude to 0.01 S/cm at 700 °C compared to that of NaNbO3 oxides. This study not only discovered the novel ionic conductor properties of Na0.4Bi0.2NbO3, but also provided a new candidate for the solid electrolyte of medium-temperature solid oxide fuel cells (IT-SOFCs).

An investigation on mechanical, electrical, and rheological characteristics of ultra‐high molecular weight (UHMW)‐EPDM/PP blends‐based conductive thermoplastic vulcanizates (CTPVs)

AbstractA new generation conductive thermoplastic vulcanizates (CTPVs) have been developed and characterized in detail, which is based on ultra‐high molecular weight (UHMW)‐EPDM rubber combined with conductive carbon black (CCB) filler. The influence of incorporation of CCB filler in the CTPV matrix on various relevant properties has been studied thoroughly. Physico‐mechanical properties indicate a significant improvement in the tensile strength, modulus, crosslink density, and tear strength together with quite good flexibility of the CTPVs. Rheological properties depict excellent processability and material strength (storage‐modulus and complex‐modulus), and stress relaxation shows a higher relaxation time of the CTPVs over the pristine‐TPV. Morphology study (AFM, FESEM, and TEM) reveals very well dispersion of the CCB‐filler and droplet type dispersed morphology has been achieved. The study of the electrical properties demonstrates that fair AC conductivity can be achieved for high filler loading. AC impedance analysis also proves the improvement for CTPVs over the pristine TPV. It is well described that due to the incorporation of the CCB‐filler, all the properties are improved, and from some of the results amount of CCB‐filler can also be optimized. UHMW‐EPDM/PP‐based conductive TPVs (CTPVs) can be potentially used as a sensitive stretchable conductor for various applications.

Diffusion mechanism in a sodium superionic sulfide-based solid electrolyte: Na11Sn2AsS12

Recently, in all solid-state batteries, sulfide-based solid electrolytes have received increased attention due to their high ionic conductivity, good mechanical features, and better chemical stability. Therefore, in the present study, we have synthesized a novel sodium superionic conducting sulfide-based inorganic solid electrolyte (Na11Sn2AsS12) using a solid-state reaction method. The prepared solid electrolyte (Na11Sn2AsS12) is characterized by different techniques such as x-ray diffractometry (XRD), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy, thermogravimetric analysis (TGA), electrochemical impedance spectroscopy, and linear sweep voltammetry to study its various properties such as structure, surface morphology, thermal stability, dielectric properties, ionic conductivity, and electrochemical stability window for sodium ion battery (SIB) applications. The XRD analysis confirms two coexisting phases—tetragonal and cubic, with phase fractions of 0.69 and 0.31, respectively. The SEM study reveals the irregular shape and dense morphology of the solid electrolyte. On the other hand, TGA shows that the prepared solid electrolyte is suitable for high temperature battery applications. The ionic and transport studies confirm that the synthesized Na11Sn2AsS12 is purely ionic in nature, with ionic conductivity found to be S cm−1 and negligible electronic conductivity ∼ S cm−1 at room temperature. Furthermore, the detailed ionic conduction mechanism is studied using temperature and frequency-dependent AC impedance analysis. In addition, the synthesized solid electrolyte Na11Sn2AsS12 exhibits a wide electrochemical window (∼7.0 V) and a high diffusion coefficient ( cm2 s−1) showing suitable electrolyte properties for solid-state SIB applications.

Preparation and Characterization of Electric Double-Layer Capacitors Having a 3D Stainless-Steel Fiber Sheet as the Current Collector.

One strategy to improve the performance of electric double-layer capacitors (EDLCs) is changing the current collector material. In this study, a three-dimensional porous current collector comprising stainless-steel fibers is fabricated using a relatively simple method. Capacitor properties of the EDLC using this unique current collector are characterized by cyclic voltammetry and charge–discharge tests. The voltammograms of the EDLC develop a more butterfly shape and an increased specific capacity at higher electrolyte concentrations. It shows reversible charge–discharge potential profiles, little capacity degradation (∼98% of the initial capacity at 1000th cycle), and a good rate performance at higher electrolyte concentrations (90% capacity retention for 2.5 times increase in discharge current). Its capacitance values (95–99 F g–1) are roughly twice the specific capacitance of an EDLC using the flat stainless-steel plate current collector (51 F g–1) without any performance degradation even at a higher loading of electrode active materials. Based on the AC impedance analysis, these good properties are attributed to the reduction in several resistances compared to the case of a flat stainless-steel plate: (i) the contact resistance between the electrode active material and the current collector, (ii) the resistance of the electrolyte in the finely branched space formed by the fibers and the active material, and (iii) the resistance in the diffusion layer. Increasing the electrolyte concentration further reduces the latter two resistances and the bulk electrolyte resistance, resulting in higher performance of the EDLC using the stainless-steel fiber sheet current collector.

Development and characterization of eco-friendly biopolymer gellan gum based electrolyte for electrochemical application

Abstract Magnesium ion conducting eco-friendly biopolymer electrolyte based on gellan gum has been developed by solution casting technique and characterized by XRD, FTIR, DSC, AC impedance analysis and LSV. Amorphous nature of the polymer electrolyte has been confirmed by XRD analysis. FTIR analysis confirms the complex formation between gellan gum and magnesium nitrate salt. Glass transition temperature of the polymer electrolytes have been found in DSC analysis. Ionic conductivity of polymer electrolyte membrane has been analysized by AC impedance studies, polymer electrolyte 1.0 g gellan gum with 0.7 wt% Mg (NO3)2 has highest ionic conductivity 1.392 × 10−2 S/cm at room temperature. Evan’s polarization method attributes Mg+ cationic transference number as 0.342 for high conducting polymer electrolyte. The high conducting polymer membrane has electrochemical stability 3.58 V. Using this high conducting polymer electrolyte, magnesium ion battery is constructed and the battery performance was studied. The open circuit voltage is found as 1.99 V.

AC Impedance Analysis of the Degeneration and Recovery of Argyrodite Sulfide-Based Solid Electrolytes under Dry-Room-Simulated Condition

AC Impedance Analysis of the Degeneration and Recovery of Argyrodite Sulfide-Based Solid Electrolytes under Dry-Room-Simulated Condition

Fabrication of Fluorite and Perovskite Functional Films by Solution Spray Pyrolysis

Solution Spray Pyrolysis (SST) was successfully implemented to fabricate thin perovskite and fluorite films on dense Yttria Stabilized Zirconia (YSZ) and Lanthanum Strontium Ferrate (LSF70) substrates. These composite structures are ubiquitous in solid oxide fuel cells and electrolyzers, CO gas sensors and ceramic membranes. With this technique, successful in situ manipulation of the film’s functional characteristics such as porosity and thickness is easily achieved by adjusting its functional parameters.In the present contribution, we report on the optimization of the physicochemical parameters of this open atmosphere technique with respect to the substrate temperature and deposition time for the fabrication of films of suitable morphology. Sintered films were characterized by XRD and SEM while thermal analysis was performed on the precursor salts. In addition, AC Impedance analysis was performed on some CGO films in order to assess their electron blocking capability in contact with the LSF substrates.

Effect of size of the filler on the electrical conductivity of magnesium ion conducting polymer electrolyte

The electrical characteristic studies on new polymer electrolyte system ((PMMA)x- ((Mg(CF3SO3)2)1-x)y - (TiO2)1-y have been explored in association with structural characterization, where in amorphous polymer PMMA is mixed with magnesium triflate salt and the filler TiO2.The constituent phases of the synthesized samples by solution casting technique were investigated by powder X-ray Diffraction analysis (XRD) and spectral analysis by Fourier Transform Infra-Red spectroscopy (FTIR).Surface morphology of the prepared samples were carried out by Scanning Electron Microscopy (SEM).The electrical conductivity studies were undertaken with the help of AC impedance analysis to the four different compositions of the synthesized System I with the addition of titanium dioxide of particle size 133 nm as filler and found to exhibit electrical conductivity of the order of 10-6 to 10-7 S cm−1 at room temperature (303 K). AC impedance analysis on four different compositions of the System II with the addition of titanium dioxide of particle size 76 nm as nano filler exhibits electrical conductivity values of the order of 10-6 Scm−1 at room temperature (303 K) with one magnitude increase in ionic conductivity. The particular composition with filler size of 76 nm (((PMMA)70 – (Mg(CF3SO3)2)30)90 - (TiO2)10 shows an ionic conductivity value of 1.78 × 10-6 Scm−1 at room temperature (303 K) which could be considered as best conducting composition.

AC Impedance Analysis of NCM523 Composite Electrodes in All-Solid-State Three Electrode Cells and Their Degradation Behavior

AC Impedance Analysis of NCM523 Composite Electrodes in All-Solid-State Three Electrode Cells and Their Degradation Behavior

A Dual-Function Cobalt Metal-Organic Framework for High Proton Conduction and Selective Luminescence Sensing of Histidine

Proton exchange membrane (PEM) is a key component of proton exchange membrane fuel cells (PEMFCs). In recent years, metal organic framework (MOF) and its composite membranes have become the research hotspots. [Co(L-Glu)(H2O)·H2O]n (Co-MOF, L-Glu = L-glutamate) was synthesized by hydrothermal method. Co2+ ions are coordinated with L-Glu ligands and water molecules to form one-dimensional chains extending along the a-axis, which are further bridged by L-Glu ligands to form a three-dimensional network structure. AC impedance analysis shows that the proton conductivity of Co-MOF reaches 3.14 × 10−4 S·cm−1 under 98% relative humidity (RH) and 338 K. To improve proton conductivity, different contents of Co-MOF were added in chitosan (CS) to form composite membranes Co-MOF@CS-X (mass fraction X = 5%, 10%, 15% wt). The results show the proton conductivity of the Co-MOF@CS-10 composite membrane is 1.73 × 10−3 S·cm−1 at 358 K and 98% RH, which is more than 3 times that of pure CS. As far as we known, this is the first composite made of amino acid MOFs and CS as proton exchange membrane. Furthermore, Co-MOF has an obvious quenching effect on L-histidine in aqueous solution, which can detect the content of L-histidine in water with high sensitivity, and the detection limit is 1 × 10−7 M.

Electrochemical Corrosion Behavior of Heat-Treated HVOF Coatings on ASTM SA213-T22 Steel

Herein the electrochemical corrosion behavior of pre- and post-heat-treated composite coatings of NiCrMoFeCoAl-30%SiO2 and NiCrMoFeCoAl-30%Cr2O3 on ASTM SA213-T22 boiler tube steel by a high-velocity oxygen fuel (HVOF) spraying technique are reported. The samples were subjected to hot molten salt (Na2SO4–60%V2O5) corrosion environment in a tubular furnace at 700°C under thermocyclic conditions. The microscopic, structural, and electrochemical investigations of post-heat-treated specimens reveal NiCrMoFeCoAl-30%Cr2O3 composite HVOF coating exhibits a superior corrosion resistance compared to NiCrMoFeCoAl-30%SiO2 composite coating and bare ASTM SA213-T22 steel boiler tube steel in neutral electrolyte. The room-temperature potentiodynamic and impedance investigations of heat-treated samples suggest high interfacial charge transfer resistance for HVOF coatings over a wide anodic potential window. This could be ascribed to the protective nature of the chromium-oxide-containing coatings on high-temperature treatment. AC impedance analysis reveals NiCrMoFeCoAl-30%Cr2O3 coating exhibits very high resistive behavior with very high charge transfer resistance, in the order of 106 Ω higher than the NiCrMoFeCoAl-30%SiO2 coating and uncoated ASTM SA213-T22 steel boiler tube steel. Furthermore, the high-temperature-induced formation of metal chromates/chromites along with the presence of Cr2O3 provides good resistance toward corrosion.