scholarly journals Electrochemical Behavior of Inductively Sintered Al/TiO2 Nanocomposites Reinforced by Electrospun Ceramic Nanofibers

Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4319
Author(s):  
Hany S. Abdo ◽  
Ubair Abdus Samad ◽  
Mohamed S. Abdo ◽  
Hend I. Alkhammash ◽  
Muhammad Omer Aijaz
Keyword(s):  
Electrochemical Impedance ◽  
Sol Gel ◽  
High Energy ◽  
Optical Microscope ◽  
Corrosion Studies ◽  
Vacuum Atmosphere ◽  
Sol Gel Process ◽  
Before And After ◽  
Energy Ball ◽  
Ceramic Nanofibers

This study is focuses on the investigation of the effect of using TiO2 short nanofibers as a reinforcement of an Al matrix on the corrosion characteristics of the produced nanocomposites. The TiO2 ceramic nanofibers used were synthesized via electrospinning by sol-gel process, then calcinated at a high temperature to evaporate the residual polymers. The fabricated nanocomposites contain 0, 1, 3 and 5 wt.% of synthesized ceramic nanofibers (TiO2). Powder mixtures were mixed for 1 h via high-energy ball milling in a vacuum atmosphere before being inductively sintered through a high-frequency induction furnace at 560 °C for 6 min. The microstructure of the fabricated samples was studied by optical microscope and field emission scanning electron microscope (FESEM) before and after corrosion studies. Corrosion behavior of the sintered samples was evaluated by both electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques (PPT) in 3.5% NaCl solution for one hour and 24-h immersion times. The results show that even though the percentage of ceramic nanofibers added negatively control corrosion resistance, it is still possible to increase resistance against corrosion for the fabricated nanocomposite by more than 75% in the longer exposure time periods.

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%.

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.

Effect of Shot Peening on Microstructure and Properties of 34CrMo4 Alloy

2018 ◽  
Vol 934 ◽  
pp. 105-110 ◽  
Author(s):  
Ke Jian Li ◽  
Qiang Zheng ◽  
Yue Lin Qin ◽  
Xiao Wei Liu
Keyword(s):  
Plastic Deformation ◽  
Corrosion Resistance ◽  
Shot Peening ◽  
Electrochemical Impedance ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Microstructure And Properties ◽  
Before And After ◽  
Sever Plastic Deformation ◽  
Evolution Of Microstructure

Plastic deformation can induce surface modification, such as shot peening (SP) on workpiece surface is the hot issue of recent scientific research. SP is the efficient way to improve mechanical behavior of specimens by inducing sever plastic deformation on their surface. Nevertheless, this surface treatment induced complex microstructural evolutions such as grain refinement, will enhance the corrosion resistance of specimens. In this work, the microstructure and properties of 34CrMo4 alloy of before and after SP for 20 min have been investigated. The evolution of microstructure and properties were analyzed from the surface and cross-section. The microstructure morphology at the different depth was determined by optical microscope. The results show grain size is increasing with the depth, and the microhardness and compressive residual stress decrease gradually. In terms of corrosion resistance, the 50 μm depth specimen has the best property than other depth, which the potential and corrosion current density are-0.484 V and-5.72 Acm-2, respectively. The maximum polarization resistance is 2055 Ωcm2by capacitive arc radius of electrochemical impedance spectroscopy.

Optimizing Performance of Li4Ti5O12 (LTO) by Addition of Sn Microparticle in High Loading as Anode for Lithium-Ion Batteries

2020 ◽  
Vol 1000 ◽  
pp. 20-30
Author(s):  
Bambang Priyono ◽  
Reza Miftahul Ulum ◽  
Anne Zulfia Syahrial ◽  
Stefanie Trixie ◽  
Heri Jodi ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Lithium Ion Batteries ◽  
Surface Area ◽  
Electrochemical Impedance ◽  
Lithium Ion ◽  
High Energy ◽  
Solid State Method ◽  
High Energy Ball Mill ◽  
Before And After ◽  
Two Peaks

Li4Ti5O12/Sn was successfully synthesized by a solid-state method using the High Energy Ball Mill Machine as anode for Lithium-Ion batteries. The addition of various (10%, 20%, 30%) Sn-micro particle is aimed to enhance LTO's conductivity and capacity. Characterization of the sample's structure was performed using X-ray diffraction (XRD), which expose the presence of TiO2 rutile and Sn in each sample. The surface area of samples observed using Brunner-Emmet-Teller (BET), which indicates the different surface area of each Sn addition. Scanning electron microscopy (SEM) suggested agglomeration and poor distribution appear in every sample. Cyclic voltammetry (CV) was performed to measure the battery's performance. Two peaks occur as a sign of reversible reaction. The impedance of Li4Ti5O12/Sn measured using electrochemical impedance spectroscopy (EIS), the test performed before and after Cyclic voltammetry (CV), each test showed the different result for each sample. Other than EIS and CV, Charge-Discharge (CD) also performed, examinations in different C-rate were performed, and higher Sn concentration leads to lower stability in high C. The result reveals that the addition of 20% Sn optimizes Li4Ti5O12 in enhancing capacity and conductivity.

Recycling of Zircaloy Machining Chips by VAR Remelting and Powder Metallurgy Techniques

2012 ◽  
Vol 727-728 ◽  
pp. 356-361 ◽  
Author(s):  
Hidetoshi Takiishi ◽  
J.H. Duvaizen ◽  
I.M. Sato ◽  
J.L. Rossi ◽  
L.A.T. Pereira ◽  
...  
Keyword(s):  
Powder Metallurgy ◽  
Nuclear Reactor ◽  
Reactor Core ◽  
High Energy ◽  
Powder Metallurgy Method ◽  
High Energy Ball Mill ◽  
Before And After ◽  
Energy Ball ◽  
Near Net Shape ◽  
Small Parts

In the fabrication of nuclear reactor core parts, machining chips of Zircaloy are generated. These alloys are strategic for nuclear technology and cannot be discarded. In the present work are presented two methods for recycling of Zircaloy chips. One of the methods is by melting in VAR furnace and the other by powder metallurgy method. By this method the Zircaloy was submitted to hydriding process and milled in a high-energy ball mill. The powder was cold isostatically pressed and vacuum sintered. The elemental composition of the samples obtained by both ways was determined by XRF and compared to the specifications. The phase composition was determined by XRD. The microstructures resulting of both processing methods, before and after rolling were characterized using optical and scanning electron microscopy. The good results of the powder metallurgy method suggest the possibility of producing small parts, like cladding cap-ends, using near net shape sintering.

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.

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.

Processing Aluminum Scrap Vial Mechanical Alloying and Subsequently Hot Extrusion

2008 ◽  
Vol 591-593 ◽  
pp. 212-217
Author(s):  
Rodrigo Estevam Coelho ◽  
Paulo Jesus Costa Esteves ◽  
Jorge Ferreira Brito
Keyword(s):  
Weight Ratio ◽  
Hot Extrusion ◽  
Tensile Tests ◽  
High Energy ◽  
Optical Microscope ◽  
Fine Powders ◽  
High Energy Ball Mill ◽  
Energy Ball ◽  
Recycle Aluminum ◽  
Aluminum Cans

Recycle aluminum cans, an alternative route is presented in this work. The aluminum cans are cut in little flakes with a shears, and then the materials were milled, obtained fine powders. The weight ratio of the balls to powder was 10 to 1. Equipment of a horizontal high energy ball mill was utilized. The powder mixture was processed during 0.5, 1 and 2 hours at 950 rpm and after milling, the powders were directly hot extrusion. The extruder bars were submitted at a tensile tests and samples microstructures were analyzed by optical microscope. Experimental results obtained shows that the technique utilized in this work is very important for economized routes and consequently, less expensive, as compared with conventional methods.

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