scholarly journals λ-MnO2 Thin Films with Sponge-Like Structures: Synthesis, Characterization and Physiochemical Applications

2021 ◽  
Vol 21 (5) ◽  
pp. 1187
Author(s):  
Khalid Abdelazez Mohamed Ahmed
Keyword(s):  
Thin Films ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Impedance Spectrum ◽  
Particle Growth ◽  
Crystal Form ◽  
Electrochemical Impedance Spectrum ◽  
Significant Research ◽  
Physicochemical Features ◽  
Adsorption Desorption

Manganese dioxide has acquired significant research attentiveness in many fields over the past years because of its exciting physicochemical features. The magnetized λ-MnO2 thin films with sponge-like structures (TSLs) were prepared by hydrothermal-soft chemical and delithiation-lithium manganese process. The XRD, XPS, EDX, FESEM, TEM, HR-TEM, and N2 adsorption-desorption techniques were used to characterize the as-prepared product’s structure composition, morphology, and surface area. The particle growth details of λ-MnO2 are postulated by the oxidation-ionic change-delithiation (OID) mechanism. The electrochemical property was analyzed by galvanostatic discharge-charging, electrochemical impedance spectrum (EIS), and cyclic voltammetry (CV). Special attention of λ-MnO2 S.L.s is given to their applications in the degradation of methyl orange (MO) from wastewater under O2 air bubble pump and cathodic substance in the lithium-ion battery. Due to the peculiarity crystal form and morphology face, the λ-MnO2 TSLs might be promisingly applied in the various physicochemical area.

Research on Lithium Ion Battery Material LiCoO2 for Hybrid Supercapacitor

2011 ◽  
Vol 287-290 ◽  
pp. 1565-1568 ◽  
Author(s):  
Sheng Li Zhang ◽  
Li Hua Ma ◽  
Xiao Gang Li ◽  
Yan Hua Song ◽  
Wei Li
Keyword(s):  
Leakage Current ◽  
Composite Electrode ◽  
Electrochemical Impedance ◽  
Retention Rate ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Impedance Spectrum ◽  
Constant Current ◽  
Electrochemical Impedance Spectrum ◽  
Hybrid Supercapacitor

The electrochemical performance of capacitor was studied with LiCoO2/AC as composite cathode and activated carbon (AC) as anode, in 1.0 mol/L LiPF6/EC+DMC electrolyte. Cyclic Voltammetary, Constant-Current Charge and Discharge, Electrochemical Impedance Spectrum (EIS) and Leakage Current Test were tested to study the characteristics of supercapacitors. The results illustrate that recharging voltage of hybrid supercapacitor can reach to 3.0 V and show good capacitance characteristics. The supercapacitor can rapidly charge and discharge and show good cycling performance. There is a great effect to the performance of the capacitors by adopting different proportional composite electrode. When the ratio of composite electrode is 6:4, we get maximum symmetrical Cyclic Voltammetary and short charge-discharge time only 26.4min; When the ratio is 7:3, the minimum AC impedance of 26.2W can be attained and least leakage current is only 19.92mA/g; When the ratio is 5:5, the best first specific capacity can reach to 70.17F/g but a lower capacity retention rate is 74.86%.

Study on Electrochemical Impedance Spectrum Analysis of LiFePO4 in Aqueous Solutions by Using Powder Microelectrode

2013 ◽  
Vol 805-806 ◽  
pp. 1348-1351
Author(s):  
Na Ha ◽  
Jie Min Liu
Keyword(s):  
Cathode Materials ◽  
Electrochemical Method ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
Impedance Spectrum ◽  
Electrochemical Impedance Spectrum ◽  
Quick Response ◽  
Modeling Process ◽  
Electrochemical Parameters ◽  
Powder Microelectrode

LiFePO4 is becoming promising lithium ion cathode material. Because period of testing call is long, sometimes it cannot accurately characterize for cathode materials. By using Electrochemical Impedance Spectrum, it would be better to describe performance of materials. The electrochemical parameters have been obtained by modeling process of insertion and desertion by Electrochemical Impedance Spectrum, which is helpful to analyze LiFePO4 electrochemical performance. Because of quick response and preciseness of electrochemical method, it would be better to analyze cathode materials.

scholarly journals The Influence of Dopant Concentration on Optical-Electrical Features of Quantum Dot-Sensitized Solar Cell

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2865
Author(s):  
Dang Huu Phuc ◽  
Ha Thanh Tung ◽  
Van-Cuong Nguyen ◽  
My Hanh Nguyen Thi
Keyword(s):  
Thin Films ◽  
Quantum Dot ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Photocurrent Density ◽  
Band Gap Energy ◽  
Electrochemical Impedance Spectrum ◽  
X Ray Diffraction ◽  
Electron Phonon Interaction ◽  
Optical Films

In this study, TiO2/CdS/CdxCu1−xSe, TiO2/CdS/CdxMn1−xSe, and TiO2/CdS/CdxAg2−2xSe thin films were synthesized by chemical bath deposition for the fabrication of photoanode in quantum-dot-sensitized solar cells. As a result, the structural properties of the thin films have been studied by X-ray diffraction, which confirmed the zinc Blende structure in the samples. The optical films were researched by their experimental absorption spectra with different doping concentrations. Those results were combined with the Tauc correlation to estimate the absorption density, the band gap energy, valence band and conduction band positions, steepness parameter, and electron–phonon interaction. Furthermore, the electrical features, electrochemical impedance spectrum and photocurrent density curves were carried out. The result was used to explain the enhancing performance efficiency.

scholarly journals PEO Infiltration of Porous Garnet-Type Lithium-Conducting Solid Electrolyte Thin Films

Ceramics ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 421-436
Author(s):  
Aamir Iqbal Waidha ◽  
Vanita Vanita ◽  
Oliver Clemens
Keyword(s):  
Thin Films ◽  
Solid State ◽  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Three Dimensional ◽  
Lithium Ion ◽  
Interfacial Resistance ◽  
Composite Electrolytes ◽  
Ion Conducting ◽  
Polymer Infiltration

Composite electrolytes containing lithium ion conducting polymer matrix and ceramic filler are promising solid-state electrolytes for all solid-state lithium ion batteries due to their wide electrochemical stability window, high lithium ion conductivity and low electrode/electrolyte interfacial resistance. In this study, we report on the polymer infiltration of porous thin films of aluminum-doped cubic garnet fabricated via a combination of nebulized spray pyrolysis and spin coating with subsequent post annealing at 1173 K. This method offers a simple and easy route for the fabrication of a three-dimensional porous garnet network with a thickness in the range of 50 to 100 µm, which could be used as the ceramic backbone providing a continuous pathway for lithium ion transport in composite electrolytes. The porous microstructure of the fabricated thin films is confirmed via scanning electron microscopy. Ionic conductivity of the pristine films is determined via electrochemical impedance spectroscopy. We show that annealing times have a significant impact on the ionic conductivity of the films. The subsequent polymer infiltration of the porous garnet films shows a maximum ionic conductivity of 5.3 × 10−7 S cm−1 at 298 K, which is six orders of magnitude higher than the pristine porous garnet film.

Estimation of Li-Ion Diffusion Coefficients in C60 Coated Si Thin Film Anodes Using Electrochemical Techniques

2012 ◽  
Vol 326-328 ◽  
pp. 87-92 ◽  
Author(s):  
Arenst Andreas Arie ◽  
Joong Kee Lee
Keyword(s):  
Thin Films ◽  
Diffusion Coefficients ◽  
Electrochemical Impedance ◽  
Silicon Film ◽  
Electrochemical Techniques ◽  
Lithium Ion ◽  
Chemical Vapor ◽  
Film Coating ◽  
Kinetic Properties ◽  
Silicon Thin Films

C60coated Si thin films were prepared sequentially by a plasma enhanced chemical vapor deposition and a plasma assisted thermal evaporation technique. The films were then utilized as anode materials for lithium ion batteries. The diffusion coefficients of Li-ions in the film electrodes were then estimated by typical electrochemical techniques such as cyclic voltammetry and electrochemical impedance spectroscopy. The diffusion coefficients determined by both methods were found to be consistent each other. The diffusion coefficient of coated samples was obviously higher than that of bare silicon thin films, indicated that the kinetic properties of lithium ion transport in silicon film electrodes were enhanced by the C60film coating on its surface.

scholarly journals Study on the Synthesize, Characterization, and Conductive Performance of Nickelzircomolybdnum Heteropoly Acid Salt with Keggin Structure

2019 ◽  
Vol 2019 ◽  
pp. 1-4
Author(s):  
Zhihong Zhang ◽  
Baoying Wang ◽  
Yijing Zhang ◽  
Gehong Zhang ◽  
Yujing Wang
Keyword(s):  
Conduction Mechanism ◽  
Heteropoly Acid ◽  
Electrochemical Impedance ◽  
Impedance Spectrum ◽  
Heteropoly Compound ◽  
Electrochemical Impedance Spectrum ◽  
Acid Salt ◽  
X Ray Diffraction ◽  
Protonic Conduction ◽  
X Ray

A novel heteropoly acid salt, Na6[Ni(Mo11ZrO39)]·20H2O, has been synthesized by the means of acidification and adding the reactants into the solution step by step. The heteropoly compound was characterized by elemental analysis, TGA/DSC, infrared spectrum, ultraviolet spectrum, X-ray diffraction, and SEM. Its protonic conduction was measured by the means of the electrochemical impedance spectrum. The results showed that it belongs to the Keggin type, and its conductivity value was 1.23 × 10–2 S/cm at 23°C when the relative humidity was 60%, and the conductivity enhanced with the elevated temperature. Its proton conduction mechanism was in accordance with vehicle mechanism, and the activation energy was 27.82 kJ/mol.

Fe-Doped UiO-66 Combined with ZnIn2S4 for Adsorption and Degradation of RhB Under Visible Light

NANO ◽  
2020 ◽  
Vol 15 (07) ◽  
pp. 2050089
Author(s):  
Litong Niu ◽  
Shaoping Hu ◽  
Yali Ma ◽  
Mingming Wang ◽  
Bolin Lv ◽  
...  
Keyword(s):  
Visible Light ◽  
Electrochemical Impedance ◽  
Diffuse Reflectance Spectroscopy ◽  
Photogenerated Electron ◽  
Impedance Spectrum ◽  
Solvothermal Reaction ◽  
Electrochemical Impedance Spectrum ◽  
X Ray Diffraction ◽  
One Pot ◽  
Ft Ir

Novel ZnIn2S4/FeUiO-66 (ZFeU) photocatalyst with different proportion of FeUiO-66 has been successfully prepared by a facile one-pot solvothermal reaction. The as-synthesized nanocomposites have been thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform-infrared spectroscopy (FT-IR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS), Brunauer–Emmett–Teller (BET) characterization, photoluminescence (PL) analysis and electrochemical impedance spectrum (EIS). The photocatalytic performance of ZFeU nanocomposites for the photodegradation of RhB under visible light irradiation was better than that of ZnIn2S4 and FeUiO-66 alone. The experiment results showed the 20% ZFeU nanocomposites had the best photocatalytic properties. At the same time, a probable mechanism was discussed and it was believed that introduction of FeUiO-66 on ZnIn2S4 would minimize the recombination of photogenerated electron-hole pairs, leading to the enhancement of the photocatalytic activity.

EIS Study of Corrosion Behavior of Hot-Dip Galvanized Steel in 5% NaCl Aqueous Solution

2011 ◽  
Vol 335-336 ◽  
pp. 779-782
Author(s):  
Shi Quan He ◽  
Hui Zhong
Keyword(s):  
Aqueous Solution ◽  
Equivalent Circuit ◽  
Corrosion Behavior ◽  
Immersion Time ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Impedance Spectrum ◽  
Corrosion Products ◽  
Galvanized Steel ◽  
Electrochemical Impedance Spectrum

Corrosion behaviour of hot-dip galvanized steel in 5% NaCl aqueous solution was studied by electrochemical impedance spectrum (EIS) technique. The results revealed that corrosion behaviour of hot-dip galvanized steel has a great relationship with immersion time. With the increase of immersion time, corrosion products are constantly changing, and the impedance of corrosion products are different. Parameters fitted by equivalent circuit show that the impedance of corrosion products increased at first, then decreased.

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