Synthesis, Characterization and Pseudocapacitive Behaviour of MnOx/CNT Heterostructures

2013 ◽  
Vol 1577 ◽  
Author(s):  
Chung-Ying Tsai ◽  
Kanchan Mondal ◽  
S. Talapatra
Keyword(s):  
Manganese Oxide ◽  
Specific Capacitance ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Manganese Acetate ◽  
Hybrid Sample ◽  
Sol Gel Process ◽  
Electrode Systems ◽  
Superior Electrochemical Properties ◽  
Dominant Phase

ABSTRACTManganese oxide based nanoparticles were synthesized by sol-gel process. Methanol, ethanol, and propanol were used as alternative solvent during sol-gel process with manganese acetate as precursor for the preparation of pristine manganese oxide. Hybrid MnOx modified by additions of carbon nanotubes was further prepared. Smallest particle size was observed for manganese oxide prepared from propanol, with diameters range from 16 nm to 50nm. XRD results showed that the as prepared manganese oxide based samples at calcination temperature of 300°C and above were composed of Mn2O3 as dominant phase, with Mn3O4 as minor phase. Specific capacitance measured from two electrode systems of manganese oxide prepared from methanol, ethanol, and propanol at scan rate of 10 mV/s were 88.3, 66.0, 104.8 F/g and the result for the hybrid sample was 140.5 F/g. The highest capacitance of the MnOx revealed a specific capacitance of 231.4 F/g when a 1:1 mixture of propanaol and methanol was employed as the solvent for the sol preparation. Results from electrochemical impedance spectroscopy (EIS) also showed superior electrochemical properties of the hybrid sample over pristine manganese oxide samples.

Electrochemical Performance Optimization of Li2NixFe1−xSiO4 Cathode Materials for Lithium-Ion Batteries

2017 ◽  
Vol 14 (2) ◽  
Author(s):  
Atef Y. Shenouda ◽  
M. M. S. Sanad
Keyword(s):  
Performance Optimization ◽  
Electrochemical Impedance ◽  
Coulombic Efficiency ◽  
Sol Gel ◽  
Lithium Ion ◽  
Electrochemical Impedance Spectra ◽  
Cell Parameters ◽  
Sol Gel Process ◽  
Eis Measurements ◽  
And Function

Li2NixFe1−xSiO4 (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) samples were prepared by sol–gel process. The crystal structure of prepared samples of Li2NixFe1−xSiO4 was characterized by XRD. The different crystallographic parameters such as crystallite size and lattice cell parameters have been calculated. Scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) investigations were carried out explaining the morphology and function groups of the synthesized samples. Furthermore, electrochemical impedance spectra (EIS) measurements are applied. The obtained results indicated that the highest conductivity is achieved for Li2Ni0.4Fe0.6SiO4 electrode compound. It was observed that Li/Li2Ni0.4Fe0.6SiO4 battery has initial discharge capacity of 164 mAh g−1 at 0.1 C rate. The cycle life performance of all Li2NixFe1−xSiO4 batteries was ranged between 100 and 156 mAh g−1 with coulombic efficiency range between 70.9% and 93.9%.

Amorphous Thin Film Ruthenium Oxide as an Electrode Material for Electrochemical Capacitors

1995 ◽  
Vol 393 ◽  
Author(s):  
T.R. Jow ◽  
J.P. Zheng
Keyword(s):  
Specific Capacitance ◽  
Chloride Solution ◽  
Sol Gel ◽  
Ruthenium Oxide ◽  
Metal Alkoxide ◽  
Oxide Electrode ◽  
Preparation Temperature ◽  
Amorphous Thin Film ◽  
Sol Gel Process ◽  
Alkoxide Precursor

ABSTRACTRuthenium oxide thin films of an amorphous phase were successfully prepared on a titanium (Ti) substrate at temperatures below 160 °C. The sol-gel process using metal alkoxide precursor in nonaqueous solvents was used to prepare these films. The preliminary results showed that a specific capacitance of 430 F/g can be achieved for amorphous ruthenium oxide electrode in sulfuric acid. Films prepared by this method are compared with the films prepared by the thermal decomposition of the aqueous ruthenium chloride solution at temperatures above 300 °C. The specific capacitance, the crystalline structure, and the surface morphology of these films as a function of the preparation temperature were also discussed.

scholarly journals Improved Electrochemical Performance of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 Cathode Material Synthesized by the Polyvinyl Alcohol Auxiliary Sol-Gel Process for Lithium-Ion Batteries

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
He Wang ◽  
Mingning Chang ◽  
Yonglei Zheng ◽  
Ningning Li ◽  
Siheng Chen ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Cathode Material ◽  
Discharge Capacity ◽  
Electrochemical Impedance ◽  
Coulombic Efficiency ◽  
Sol Gel ◽  
Rate Capability ◽  
Lithium Ion ◽  
Transfer Resistance ◽  
Sol Gel Process

A lithium-rich manganese-based cathode material, Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2, was prepared using a polyvinyl alcohol (PVA)-auxiliary sol-gel process using MnO2 as a template. The effect of the PVA content (0.0–15.0 wt%) on the electrochemical properties and morphology of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 was investigated. Analysis of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 X-ray diffraction patterns by RIETAN-FP program confirmed the layered α-NaFeO2 structure. The discharge capacity and coulombic efficiency of Li1.25Ni0.2Co0.333Fe0.133Mn0.333O2 in the first cycle were improved with increasing PVA content. In particular, the best material reached a first discharge capacity of 206.0 mAhg−1 and best rate capability (74.8 mAhg−1 at 5 C). Meanwhile, the highest capacity retention was 87.7% for 50 cycles. Finally, electrochemical impedance spectroscopy shows that as the PVA content increases, the charge-transfer resistance decreases.

Novel Electrode Materials for Ultracapacitors:Structural and Electrochemical Properties of Sol-Gel-Derived Manganese Dioxide Thin Films

1999 ◽  
Vol 575 ◽  
Author(s):  
Suh-Cern Pang ◽  
MarcA Anderson
Keyword(s):  
Thin Films ◽  
Specific Capacitance ◽  
Electrode Materials ◽  
Sol Gel ◽  
High Specific Capacitance ◽  
Potential Range ◽  
Proton Mobility ◽  
Reversible Redox ◽  
Sol Gel Process ◽  
Nickel Substrates

ABSTRACTNanoparticulate MnO2thin films fabricated by the sol-gel process have been shown to be an outstanding novel electrode material for Ultracapacitors. The average specific capacitance of sol-gel-derived MnO2thin-films on nickel substrates as determined by cyclic voltammetry ranged from 566 to 698 F/g. These films also exhibited good cycling stability within the potential range of 0.0-0.9V (vs SCE) in unbuffered aqueous electrolyte. Both CV and XPS studies showed that MnO2films have remained chemically and structurally intact after 1,500 cycles. The XRD spectra and SEM micrographs showed that the microstructure of MnO2thin films are highly porous, and poorly crystalline or amorphous in nature. The high specific capacitance of MnO2may be predominantly due to pseudocapacitance associated with homogenous and reversible redox reactions of proton insertion into and out of the MnO2lattice. Any variation in the microstructure and thickness of films might affect proton mobility within the oxide matrix and thereby affecting their cycling behaviors. Further optimization of the cycling behaviors is envisaged with better microstructural and thickness control of these sol-gelderived nanoparticulate MnO2thin films.

scholarly journals High Specific Capacitance of the Electrodeposited MnO2 on Porous Foam Nickel Soaked in Alcohol and its Dependence on Precursor Concentration

Materials ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 181 ◽  
Author(s):  
Ming Zhang ◽  
Xiaoli Dai ◽  
Cuixian Zhang ◽  
Yuanwu Fuan ◽  
Dingyu Yang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Specific Capacitance ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Retention Rate ◽  
Nickel Foam ◽  
Three Dimensional ◽  
High Specific Capacitance ◽  
Manganese Acetate ◽  
Mixed Solution

In this work, we used the mixed solution of manganese acetate and sodium sulfate to deposit manganese dioxide on the three-dimensional porous nickel foam that was previously soaked in alcohol, and then the effects of solution concentrations on their capacitance properties were investigated. The surface morphology, microstructure, elemental valence and other information of the material were observed by scanning electron microscope (SEM), Transmission Electron Microscope (TEM), X-ray photoelectron spectroscopy (XPS), etc. The electrochemical properties of the material were tested by Galvanostatic charge-discharge (GCD), Cyclic Voltammetry (CV), Chronoamperometry (CA), Electrochemical impedance spectroscopy (EIS), etc. The MnO2 electrode prepared at lower concentrations can respectively reach a specific capacitance of 529.5 F g−1 and 237.3 F g−1 at the current density of 1 A g−1 and 10 A g−1, and after 2000 cycles, the capacity retention rate was still 79.8% of the initial capacitance, and the energy density can even reach 59.4 Wh Kg−1, while at the same time, it also has a lower electrochemical impedance (Rs = 1.18 Ω, Rct = 0.84 Ω).

scholarly journals Corrosion Behavior of Amorphous Sol–Gel TiO2–ZrO2 Nano Thickness Film on Stainless Steel

Coatings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 988
Author(s):  
Lidija Ćurković ◽  
Helena Otmačić Ćurković ◽  
Irena Žmak ◽  
Mihone Kerolli Mustafa ◽  
Ivana Gabelica
Keyword(s):  
Stainless Steel ◽  
Corrosion Behavior ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Chelating Agent ◽  
Dip Coating ◽  
Emission Spectrometry ◽  
Aisi 316L ◽  
Corrosion Properties ◽  
Sol Gel Process

In this work, a single-layer TiO2–ZrO2 thin film is deposited on the AISI 316L austenitic stainless steel by the sol–gel process and the dip coating method to improve its corrosion resistance properties. For the sol preparation, titanium isopropoxide and zirconium butoxide are used as the precursors, yttrium acetate hydrate is used for the ZrO2 stabilization, i-propanol as the solvent, nitric acid as the catalyst, acetylacetone as the chelating agent, and the distilled water for the hydrolysis. The deposited films are annealed at 400 °C or 600 °C. Morphology and phase composition of the sol–gel TiO2–ZrO2 films and powders are analyzed by scanning electron microscopy (SEM) equipped with EDX detector and X-ray diffraction (XRD), respectively. The thickness of the sol–gel TiO2–ZrO2 films deposited on the stainless steel is determined by glow discharge optical emission spectrometry (GD-OES). The corrosion behavior of the stainless steel, coated by amorphous films, is evaluated in 3 wt% NaCl and 0.5 mol dm−3 HCl by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. It is found that the sol–gel TiO2–ZrO2 films with the amorphous structure, deposited by the sol–gel process, and calcined at 400 °C significantly enhance the corrosion properties of AISI 316L in both chloride media.

scholarly journals A Sol-Gel Process for the Synthesis of NiCo2O4Having Improved Specific Capacitance and Cycle Stability for Electrochemical Capacitors

2012 ◽  
Vol 159 (8) ◽  
pp. A1262-A1266 ◽  
Author(s):  
Mao-Cheng Liu ◽  
Ling-Bin Kong ◽  
Chao Lu ◽  
Xiao-Ming Li ◽  
Yong-Chun Luo ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Sol Gel ◽  
Electrochemical Capacitors ◽  
Cycle Stability ◽  
Sol Gel Process
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