scholarly journals Enhancing the Stability of LiNi0.5Mn1.5O4 by Coating with LiNbO3 Solid-State Electrolyte: Novel Chemically Activated Coating Process versus Sol-Gel Method

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 548
Author(s):  
Valeriu Mereacre ◽  
Pirmin Stüble ◽  
Ahmad Ghamlouche ◽  
Joachim R. Binder
Keyword(s):  
Electrochemical Properties ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Coating Material ◽  
Coating Process ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Coated Materials ◽  
The Stability

LiNbO3-coated LiNi0.5Mn1.5O4 spinel was fabricated by two methods: using hydrogen-peroxide as activating agent and sol-gel method. The structure of the obtained cathode materials was investigated using a scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and the electrochemical properties of the prepared cathodes were probed by charge-discharge studies. The morphology of the coating material on the surface and the degree of coverage of the coated particles were investigated by SEM, which showed that the surface of LiNi0.5Mn1.5O4 particles is uniformly encapsulated by lithium innovate coating. The influence of the LiNbO3 coating layer on the spinel’s properties was explored, including its effect on the crystal structure and electrochemical performance. XRD studies of the obtained coated active materials revealed very small expansion or contraction of the unit cell. From the capacity retention tests a significant improvement of the electrochemical properties resulted when a novel chemically activated coating process was used. Poorer results, however, were obtained using the sol-gel method. The results also revealed that the coated materials by the new method exhibit enhanced reversibility and stability compared to the pristine and reference ones. It was shown that the morphology of the coating material and possible improvement of communication between the substrates play an important role.

scholarly journals Effects of Palladium Doping on the Structure and Electrochemical Properties of LiFePO4/C Prepared using the Sol-gel Method

2014 ◽  
Vol 17 (2) ◽  
pp. 091-097 ◽  
Author(s):  
M. Talebi-Esfandarani ◽  
O. Savadogo
Keyword(s):  
Electrochemical Properties ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Lithium Ion ◽  
Lattice Parameters ◽  
Area Measurement ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Palladium Doping

LiFePO4/C, LiFe0.98Pd0.02PO4/C, and LiFe0.96Pd0.04PO4/C composite cathode materials were synthesized using the sol-gel method. The effect of palladium on the structure and electrochemical properties of LiFePO4/C have been investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), surface area measurement (BET), charge/discharge testing, and cyclic voltammetry (CV). The results indicate that palladium doping facilitates the formation of impurities, like Li3PO4. Also, the lattice parameters of the LiFePO4 structure decrease in size as the palladium content increases. In addition, the particles become larger and agglomerated by palladium incorporation. The electrochemical results show that palladium doping decreases the electrochemical performance of LiFePO4/C, owing to shrinking lattice parameters and the difficulty of achieving the diffusion of lithium ions into the structure during the intercalation/de-intercalation process. These results suggest that palladium doping by sol-gel method changes significantly the LiFePO4 structure which may impact it performances as cathode for the lithium ion battery applications.

scholarly journals Synthesis, characterization and in vitro cytotoxicity study of Co and Ni ferrite nanoparticles prepared by sol-gel method

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Alexandre Pancotti ◽  
Dener Pereira Santos ◽  
Dielly Oliveira Morais ◽  
Mauro Vinícius de Barros Souza ◽  
Débora R. Lima ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Test Sample ◽  
In Vitro Cytotoxicity ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Transmission Electron ◽  
Crystallite Sizes

AbstractIn this study, we report the synthesis and characterization of NiFe2O4 and CoFe2O4 nanoparticles (NPs) which are widely used in the biomedical area. There is still limited knowledge how the properties of these materials are influenced by different chemical routes. In this work, we investigated the effect of heat treatment over cytotoxicity of cobalt and niquel ferrites NPs synthesized by sol-gel method. Then the samples were studied using transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), Fourier Transform Infrared Spectroscopy Analysis (FTIR), and X-ray fluorescence (XRF). The average crystallite sizes of the particles were found to be in the range of 20–35 nm. The hemocompatibility (erythrocytes and leukocytes) was checked. Cytotoxicity results were similar to those of the control test sample, therefore suggesting hemocompatibility of the tested materials.

Magnetic Properties of Bulk Zn0.95-XMnXFe0.05O2 Prepared by Sol-Gel Method and Subsequent Hot Pressing

2011 ◽  
Vol 268-270 ◽  
pp. 356-359 ◽  
Author(s):  
Wen Song Lin ◽  
C. H. Wen ◽  
Liang He
Keyword(s):  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Raw Materials ◽  
Sol Gel ◽  
Secondary Phase ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Doped Zno

Mn, Fe doped ZnO powders (Zn0.95-xMnxFe0.05O2, x≤0.05) were synthesized by an ameliorated sol-gel method, using Zn(CH3COO)2, Mn(CH3COO)2and FeCl2as the raw materials, with the addition of vitamin C as a kind of chemical reducer. The resulting powder was subsequently compacted under pressure of 10 MPa at the temperature of 873K in vacuum. The crystal structure and magnetic properties of Zn0.95-xMnxFe0.05O2powder and bulk samples have been investigated by X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). X-ray photoelectron spectroscopy (XPS) was used to study chemical valence of manganese, iron and zinc in the samples. The x-ray diffraction (XRD) results showed that Zn0.95-xMnxFe0.05O (x≤0.05) samples were single phase with the ZnO-like wurtzite structure. No secondary phase was found in the XRD spectrum. X-ray photoelectron spectroscopy (XPS) showed that Fe and Mn existed in Zn0.95-xMnxFe0.05O2samples in Fe2+and Mn2+states. The results of VSM experiment proved the room temperature ferromagnetic properties (RTFP) of Mn, Fe co-doped ZnO samples.

Effect of Synthesis Conditions on the Structure and Electrochemical Properties of LiNi1/2Mn1/2O2 by Sol Gel Method

2011 ◽  
Vol 399-401 ◽  
pp. 1447-1450
Author(s):  
Zhi Yong Yu ◽  
Han Xing Liu
Keyword(s):  
Electrochemical Properties ◽  
Sol Gel ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
Capacity Fading ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Synthesis Conditions ◽  
A Current

The layered LiNi1/2Mn1/2O2 cathode materials were synthesized by a sol gel method. The effects of calcination temperature and time on the structural and electrochemical properties of the LiNi1/2Mn1/2O2 were investigated. The prepared samples were characterized by X-ray diffraction (XRD) and electrochemical analysis. The results revealed that the layered LiNi1/2Mn1/2O2 material could be optimal synthesized at temperature of 900°C for 10h. The sample prepared under the above conditions has the highest initial discharge capacity of 151 mAh/g and showed no dramatic capacity fading during 20 cycles between 2.5-4.5V at a current rate of 20mA/g.

CHARACTERISTIC ANALYSIS ON GaN NANOCRYSTALLINE POWDER PREPARED BY SOL–GEL METHOD

2007 ◽  
Vol 14 (06) ◽  
pp. 1181-1185 ◽  
Author(s):  
ENLING LI ◽  
XUEWEN WANG ◽  
SHANSHAN WANG ◽  
GUICAN CHEN
Keyword(s):  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Nanocrystalline Powder ◽  
Band Edge Emission ◽  
Characteristic Analysis ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Luminescence Peak ◽  
Strong Luminescence

Gallium nitride ( GaN ) nanocrystalline powder has been prepared by sol–gel method. The GaN powder has been confirmed as single-crystalline GaN with wurtzite structure by X-ray diffraction (XRD) and selected-area electron diffraction (SAED), and the diameter of the grains of GaN powder changes from 30 to 100 nm under transmission electron microscopy (TEM). Having been excited by 240 nm light at room temperature, GaN powder has a strong luminescence peak located at 395 nm and a weak luminescence peak located at 295 nm, attributed to GaN band-edge emission and blue-shift of the band-gap emission. Moreover, X-ray photoelectron spectroscopy (XPS) confirms the formation of the bond between Ga and N , and Raman scattering spectrum confirms A1 (TO) and E1 (TO) vibrational modes of GaN .

Preparation and Photocatalytic Properties of La, Ce and Nonmetal N Co-Doped TiO2

2016 ◽  
Vol 680 ◽  
pp. 193-197
Author(s):  
San Ti Yi ◽  
Si Qin Zhao
Keyword(s):  
Photocatalytic Activity ◽  
Photoelectron Spectroscopy ◽  
Diffuse Reflectance Spectroscopy ◽  
Uv Light ◽  
Sol Gel ◽  
Light Response ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Co Doped

TiO2, 1%La/TiO2, 1%Ce/TiO2 and a series of Laand Ce co-doped TiO2 photocatalysts were prepared by sol-gel method. Using sol-gel method combine with hydrothermal method prepared rare earth La, Ce and nitrogen co-doped TiO2 photocatalysts. The microstructure, spectroscopy performance and ion doped form of prepared samples were characterized by X-ray powder diffraction (XRD), UV-Vis diffuse reflectance spectroscopy techniques and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity of doped TiO2 were examined by measuring the photodegradation of methyl orange. The results showed that the products were all anatase TiO2 nano powder, doping Laor Cehinder the growth of TiO2 particle, further more, doping Laand Cetogether hinder the growth of TiO2 particle more effective, doping N broaden the light response range of TiO2 photocatalyst. At the same time, the photocatalytic activity results indicated that the prepared samples showed superior UV light photocatalytic activity, the sample 1% (La:Ce,9:1)-N/TiO2 showed the highest UV-vis photocatalytic activity.

scholarly journals Flame Retardance and Char Analysis of Environmental Friendly Polyurethane Hyperbranched Organic-Inorganic Hybrid Using the Sol-Gel Method

2020 ◽  
Author(s):  
Ming-Yuan Shen ◽  
Chen-Feng Kuan ◽  
Hsu-Chiang Kuan ◽  
Cing-Yu Ke ◽  
Chin- Lung Chiang*
Keyword(s):  
Flame Retardant ◽  
Hybrid Material ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
Flame Retardance ◽  
Inorganic Hybrid ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Nitrogen Phosphorus

This study used the sol–gel method to synthesize a non-halogenated hyperbranched flame retardant containing nitrogen, phosphorus and silicon, HBNPSi, which was then added to a polyurethane (PU) matrix to form an organic–inorganic hybrid material. Using 29Si nuclear magnetic resonance, energy-dispersive X-ray spectroscopy of P- and Si-mapping, scanning electron microscopy, and X-ray photoelectron spectroscopy, this study determined the organic and inorganic dispersity, morphology, and flame retardance mechanism of the hybrid material. The condensation density of the hybrid material PU/HBNPSi was found to be 74.4%. High condensation density indicates a dense network structure of the material. The P- and Si-mapping showed that adding inorganic additives in quantities of either 20% or 40% results in homogeneous dispersion of the inorganic fillers in the polymer matrix without agglomeration, indicating that the organic and inorganic phases had excellent compatibility. In the burning test, adding HBNPSi to PU resulted in the material passing the UL-94 standard at the V2 level, unlike the pristine PU, which did not meet the standard. The results demonstrated that after non-halogenated flame retardant was added to PU, the material’s flammability and dripping were lower, thereby proving that flame retardants containing elements such as nitrogen, phosphorus, and silicon exert an excellent flame retardant synergistic effect.

Characterization of LiMn0.3Co0.3Ni0.3Cr0.1O2 and LiMn0.333Co0.333Ni0.333O2 Synthesized via Sol-Gel Method: XRD, SEM and XPS Studies

2012 ◽  
Vol 545 ◽  
pp. 148-152
Author(s):  
Jaafar Mohd Hilmi ◽  
Rusdi Roshidah ◽  
Mohamed Nor Sabirin ◽  
Rosiyah Yahya ◽  
Norlida Kamarulzaman
Keyword(s):  
Layered Structure ◽  
Photoelectron Spectroscopy ◽  
Sol Gel ◽  
High Energy ◽  
Binding Energies ◽  
High Energy Density ◽  
Sem Images ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method

One of the aspects most intensively researched in the continuing improvisation of lithium battery is the search for high capacity, high energy density and high performance cathode materials. Substitution of the electroactive elements with heteroatoms is one of the promising methods. In this study, a potential cathode material with a layered structure was successfully synthesized via a sol-gel method. As a comparison, the well-known LiMn1/3Co1/3Ni1/3O2(LiMn0.333Co0.333Ni0.333O2) was also synthesized using exactly the same method and conditions. Both materials were characterized using simultaneous thermogravimetric analysis (STA), X-ray powder diffraction (XRD), field-emission scanning electron microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). The stoichiometries of the compounds were also confirmed through energy-dispersive X-ray spectroscopy (EDX) measurement. XRD results show that both compounds are single phase and impurity-free with well-ordered hexagonal layered structure characteristics of R-3m space group. Both compounds also show similar morphologies with well-formed crystals and clean surfaces as depicted by the SEM images. XPS measurement reveals that the introduction of chromium into LiMn1/3Co1/3Ni1/3O2results in a considerable change in the chemical environment as observed by significant changes in the binding energies (BE) of manganese, cobalt and nickel respectively.

Additive-Coated Si3N4 Powder Prepared By The Sol-Gel Method

1994 ◽  
Vol 346 ◽  
Author(s):  
Manzheng Ge ◽  
Honghua Kan ◽  
Hui Yang ◽  
Jianmin Qiao ◽  
Zhonghua Jiang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Coating Layer ◽  
Sol Gel ◽  
Particle Size Analysis ◽  
Size Analysis ◽  
X Ray Diffraction ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Electron Microscopies

ABSTRACTThe Y2O3-La2O3 additive-coated Si3N4 powders of about 1.5 μm in size were prepared by the sol-gel method. X-ray diffraction, X-ray photoelectron spectroscopy, differential thermal analysis, thermogravimetric analysis, electron microscopies, and particle size analysis were used to study the coating on the Si3N4 particles. The results show that properties of the bulk Si3N4 powder are not affected by using the sol-gel coating and the powders are homogeneously coated by a thin layer of the Y2O3-La2O3 additives. The structure of the Y2O3-La2O3 coating layer is amorphous or microcrystalline with a submicron thickness. The coated powders are then more sinterable, and the mechanical properties of the ceramics prepared from such powders are improved.

scholarly journals Flame Retardance and Char Analysis of an Eco-Friendly Polyurethane Hyperbranched Hybrid Using the Sol–Gel Method

2021 ◽  
Vol 13 (2) ◽  
pp. 486
Author(s):  
Ming-Yuan Shen ◽  
Chen-Feng Kuan ◽  
Hsu-Chiang Kuan ◽  
Cing-Yu Ke ◽  
Chin-Lung Chiang
Keyword(s):  
Flame Retardant ◽  
Hybrid Material ◽  
Photoelectron Spectroscopy ◽  
Flame Retardants ◽  
Sol Gel ◽  
Flame Retardance ◽  
Gel Method ◽  
X Ray ◽  
Sol Gel Method ◽  
Nitrogen Phosphorus

This study used the sol–gel method to synthesize a non-halogenated, hyperbranched flame retardant containing nitrogen, phosphorus, and silicon (HBNPSi), which was then added to a polyurethane (PU) matrix to form an organic–inorganic hybrid material. Using 29Si nuclear magnetic resonance, energy-dispersive X-ray spectroscopy of P- and Si-mapping, scanning electron microscopy, and X-ray photoelectron spectroscopy, this study determined the organic and inorganic dispersity, morphology, and flame retardance mechanism of the hybrid material. The condensation density of the hybrid material PU/HBNPSi was found to be 74.4%. High condensation density indicates a dense network structure of the material. The P- and Si-mapping showed that adding inorganic additives in quantities of either 20% or 40% results in homogeneous dispersion of the inorganic fillers in the polymer matrix without agglomeration, indicating that the organic and inorganic phases had excellent compatibility. In the burning test, adding HBNPSi to PU made the material pass the UL-94 test at the V2 level, unlike the pristine PU, which did not meet the standard. The results demonstrate that after non-halogenated flame retardant was added to PU, the material’s flammability and dripping were lower, thereby proving that flame retardants containing elements such as nitrogen, phosphorus, and silicon exert an excellent flame-retardant synergistic effect.

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