Ti-doped Lithium Iron Phosphate (LiFePO4) Cathode Materials: Synthesis and Electrochemical Evaluation

2012 ◽  
Vol 15 (2) ◽  
pp. 63-69 ◽  
Author(s):  
Keqiang Ding ◽  
Wenjuan Li ◽  
Hongwei Yang ◽  
Suying Wei ◽  
Zhanhu Guo
Keyword(s):  
Electron Microscope ◽  
Lithium Iron Phosphate ◽  
Iron Phosphate ◽  
Cycling Performance ◽  
X Ray Diffraction ◽  
Materials Synthesis ◽  
Sem Images ◽  
Solid State Method ◽  
Transmission Electron ◽  
Xrd Patterns

The Ti doped LiFePO4 samples, i.e., LiFe1-xTixPO4 (X=0.01, 0.03 and 0.05), were prepared by a modified solid state method. The obtained samples were thoroughly characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). XRD patterns indicated that an olivine-type LiFePO4 was fabricated, and SEM images revealed that the particle size of LiFe0.99Ti0.01PO4 was the smallest among the obtained samples. The charge-discharge curves showed that LiFe0.99Ti0.01PO4 delivered the discharge capacity of 153.5 mAh/g at 0.2 C, the largest one among the as-prepared samples, which is rather different from the published report that LiFe0.97Ti0.03PO4 manifested the most promising cycling performance among the samples of LiFe1-xTixPO4 (X=0.01, 0.03, 0.05, 0.07 and 0.09).

Single-Crystal Iron Nanowire Arrays

2007 ◽  
Vol 121-123 ◽  
pp. 17-20 ◽  
Author(s):  
Yue Ling Sun ◽  
Ying Dai ◽  
L.Q. Zhou ◽  
Wen Chen
Keyword(s):  
Electron Microscope ◽  
Single Crystal ◽  
Hysteresis Loops ◽  
Nanowire Arrays ◽  
X Ray Diffraction ◽  
Easy Magnetization ◽  
Transmission Electron ◽  
Iron Nanowires ◽  
Xrd Patterns ◽  
Different Diameters

Highly ordered single-crystal iron nanowire arrays with different diameters have been fabricated in anodic aluminum oxide (AAO) templates by DC electrodeposition method. The Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) show that the iron nanowires are highly uniform and exhibit a single crystal structure. The X-ray diffraction (XRD) patterns of iron nanowire arrays indicate that most of the iron nanowire arrays have the obvious preferred orientation along the [200] direction. From the hysteresis loops of the iron nanowires, it reveals that the easy magnetization axes of nanowire arrays are along the long axis. The sample with smaller diameter (d=35nm) has a high square ratio (up to 98%) and a high coercive filed (1265Oe) when the external magnetic field is applied along axis of the nanowires. When the diameter decreases, the square ratio and the coercive field increase due to the single-domain structure and the strong shape anisotropy in the smaller diameter nanowire arrays.

Synthesis of RePO4 (Re=La, Nd, Pr, or Y) Nanowires by Chemical Precipitation in Nanochannels

2011 ◽  
Vol 181-182 ◽  
pp. 495-500 ◽  
Author(s):  
Cheng Mu ◽  
Jun Hui He
Keyword(s):  
Rare Earth ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Aao Template ◽  
Sem Images ◽  
Transmission Electron ◽  
Rare Earth Phosphate ◽  
Xrd Patterns ◽  
Uniform Diameter

Monodisperse nanowires of rare earth phosphates were synthesized by chemical precipitation method using anodic aluminum oxide (AAO) template. Scanning electron microscope (SEM) images indicated that rare earth phosphate nanowires are parallelly arranged in AAO template, all of which are in uniform diameter of about 50 nm. X-ray diffraction (XRD) patterns and high magnification transmission electron microscopy (HRTEM) images showed that the nanowires were polycrystal structure.

Improvement of the Crystallinity of La2CuO4 Nanoparticles Using the Vacuum Treatment

2021 ◽  
Vol 1028 ◽  
pp. 44-49
Author(s):  
Anita Eka Putri ◽  
Suci Winarsih ◽  
Budhy Kurniawan ◽  
Dicky Rezky Munazat ◽  
Dhawud Sabilur Razaq ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Vacuum Treatment ◽  
Vacuum Pressure ◽  
Morphological Properties ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Xrd Patterns

Nanoparticles of La2CuO4 (LCO) with different particles and crystallite size have been synthesized by the sol-gel method. The samples have been sintered at 600, 650, and 700°C. The sintering process have been performed in atmospheric pressure and vacuum pressure. The structural and morphological properties of the samples have been investigated by the X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Transmission Electron Microscope (TEM). The XRD patterns of the samples have shown that all samples crystallize in orthorhombic structure with Bmab space group. Additionally, Rietveld refinement process have shown that higher sintering temperature, as well sintering process under vacuum pressure, can improve both phase purity and the crystallinity of the samples. SEM and TEM results have also shown that higher sintering temperature results in a sample with larger particle size.

THE ASSEMBLY OF CHAIN-LIKE Ni ARRAYS UNDER MAGNETIC FIELD AND ITS ENHANCED PROPERTIES

2010 ◽  
Vol 09 (05) ◽  
pp. 543-547 ◽  
Author(s):  
JUN WANG ◽  
SHIHE CAO ◽  
SIHUA XIA ◽  
NING GAN
Keyword(s):  
Magnetic Field ◽  
Electron Microscope ◽  
External Magnetic Field ◽  
Self Assembly ◽  
Hydrothermal Process ◽  
X Ray Diffraction ◽  
Vertical Arrays ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Facile Hydrothermal Process

Chain-like nickel arrays assembled from magnetic Ni spheres were successfully prepared through a facile hydrothermal process at 200°C under a 0.25 T external magnetic field. The external magnetic field is strongly believed to be the driving force of the self-assembly. The sample was highly crystalline as confirmed by the X-ray diffraction (XRD) patterns. The scanning electron microscope (SEM) and transmission electron microscope (TEM) images show that all Ni spheres are closely interconnected to form chains, with ~ 950 nm in diameter and ~ 1 cm in length, which arrange into vertical arrays on the silicon substrate. The coercivity and remnant magnetization ratio of the sample, 670 Oe and 0.612, respectively, are substantially higher than for the sample prepared without an applied external magnetic field (68 Oe and 0.336). Such enhancements can be attributed to their novel superstructure, shape anisotropy, reduced demagnetization factor, etc. This process can be used to fabricate large arrays of uniform chains of magnetic materials and modulate their magnetic properties.

Investigation on structure of BaTi1−x NbxO3 compound prepared by rotary-hydrothermal synthesis methods

2014 ◽  
Vol 32 (3) ◽  
pp. 430-435 ◽  
Author(s):  
Arsia Khanfekr ◽  
Morteza Tamizifar ◽  
Rahim Naghizadeh
Keyword(s):  
Electron Microscope ◽  
Hydrothermal Reaction ◽  
Phase Evolution ◽  
Synthesis Methods ◽  
Structure And Properties ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractBaTi1−x NbxO3 compounds (with x = 0.0, 0.01, 0.03, 0.06, and 0.09) were synthesized by rotary-hydrothermal (RH) method. The process was conducted at 180 °C for 5 hours in a Teflon vessel that was rotated at a speed of 160 rpm during the hydrothermal reaction. The effects of donor concentration on the structure and properties of BaTi1−x NbxO3 compounds were investigated. The experiments for the BaTiO3±Nb2O3 system produced by a solid state reaction at high temperature at different concentrations of niobium, with the use of RH processing have not been reported in previous works. For the phase evolution studies, X-ray diffraction patterns (XRD) were analyzed and Raman spectroscopy measurements were performed. The transmission electron microscope (TEM) and the field emission scanning electron microscope (FE-SEM) images were taken for the detailed analysis of the grain size, surface and morphology of the compound.

ARC Discharge for the Synthesis of Monoclinic Ga2O3 Nanowires

1999 ◽  
Vol 581 ◽  
Author(s):  
Young Chul Choi ◽  
Dong Jae Bae ◽  
Seung Mi Lee ◽  
Young Soo Park ◽  
Young Hee Lee ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Arc Discharge ◽  
Average Diameter ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Crystalline Nature ◽  
Twin Defects ◽  
Xrd Patterns ◽  
Gallium Oxides ◽  
Ft Raman

ABSTRACTMonoclinic gallium oxide (β-Ga2O3) nanowires were catalytically synthesized by electric arc discharge of GaN powders mixed with a small amount (less than 5 %) of transition metals under a pressure of 500 Torr (80 %-Ar + 20 %-O2). Scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) images showed that the average diameter of the wires were about 30 nm and their lengths were as long as up to one hundred micrometer, resulting in extremely large aspect ratio. Fourier diffractogram was indicative of single crystalline nature of the β-Ga2O3 wire. HRTEM image also showed β-Ga2O3 with twin defects at the center of the wire which might play as nucleation seeds. Both X-ray diffraction (XRD) patterns and FT-Raman spectra of the wires identified the observed nanowires as monoclinic crystalline gallium oxides.

scholarly journals Synthesis and Optical Characterization of Europium Doped MY2O4 (M = Mg, Ca, and Sr) Nanophosphors for Solid State Lightening Applications

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Devender Singh ◽  
Vijeta Tanwar ◽  
Shri Bhagwan ◽  
Vandna Nishal ◽  
Suman Sheoran ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Emission Spectra ◽  
Main Peak ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Morphological Studies ◽  
Transmission Electron ◽  
Gel Combustion ◽  
Red Luminescence ◽  
Host Lattices

Trivalent europium doped yttriate nanophosphors were synthesized by rapid facile gel combustion technique. The photoluminescence (PL) properties of these Eu3+ activated MY2O4 (M = Mg, Ca, and Sr) nanophosphors showed red luminescence and exhibited excellent emission properties in their respective regions of color coordinates. Based on the excitation wavelengths multiple emission peaks were obtained. The main peak in the emission spectra was ascribed to 5D0→7F2 transition of Eu3+ ion. The structural and morphological studies were performed by the measurements of X-ray diffraction profiles, scanning electron microscope (SEM) images, and transmission electron microscope (TEM) micrographs. Furthermore, the effects of additional heating on the different host lattices of these phosphors were also studied.

scholarly journals PEMBUATAN DAN KARAKTERISASI KATALIS TIO2/KARBON AKTIF DENGAN METODE SOLID STATE

2015 ◽  
Vol 9 (1) ◽  
pp. 34 ◽  
Author(s):  
Upita Septiani ◽  
Mega Gustiana ◽  
Safni
Keyword(s):  
Solid State ◽  
Wave Number ◽  
Composite Catalyst ◽  
Not Given ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Solid State Method ◽  
X Ray ◽  
Infra Red ◽  
Xrd Patterns

Composite catalyst of TiO2/Activated Carbon (TiO2/AC) had been synthesized with successfully by solid-state method. Synthesis was done by varying the addition of AC 5%, 10% and 15% of the mass of TiO2 was used. Composite catalyst was calcinated at temperature 400°C and characterized by Fourier Transform Infra-Red (FTIR), X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). FTIR spectrum show that the absorption appearedin the regionof C=C at wave number 1600-1800 cm-1, that assumed from AC. From XRD we can see that with variated of AC do not given different XRD patterns significantly, crystal structure of composite catalyst is anatase. SEM images showed that AC prevented the aglomeration of TiO2 that would expand surface area and increased catalytic activity of TiO2.

scholarly journals Synthesis, Characterization of ZrO2:Tb3+ (1-9 mol %) Nanophosphors for Blue Lighting Applications and Antibacterial Property

2021 ◽  
Vol 12 (6) ◽  
pp. 7147-7158
Keyword(s):  
Electron Microscope ◽  
Diffuse Reflectance Spectroscopy ◽  
Light Sources ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Sem Images ◽  
X Ray ◽  
Transmission Electron ◽  
Good Homogeneity

This paper reports the structural, morphological, and antibacterial studies of ZrO2:Tb3+ nanophosphors (NPs). The ZrO2:Tb3+ NPs were synthesized by hydrothermal route using Amylamine as surfactant. ZrO2:Tb3+ nanophosphors was characterized by Powder X-ray Diffraction(PXRD), Scanning Electron Microscope (SEM),Diffuse reflectance spectroscopy (DRS), Photoluminescence(PL), Raman spectra, Fourier Transform Infrared radiation(FTIR) and Transmission Electron Microscope(TEM). PXRD analysis shows better crystallinity, cubic in-phase and good homogeneity of the synthesized phosphors were confirmed. When the Tb3+ concentration varies, we obtain blue emissions from ZrO2:Tb3+ NPs. ZrO2:Tb3+ NPs have a promising approach to blue light sources in the display application. SEM images show that ZrO2:Tb3+ nanophosphors have good morphology with a nonporous structure. TEM and SAED pattern confirms that ZrO2:Tb3+ nanophosphors are crystalline in nature. ZrO2:Tb3+ (9mol %) nanophosphors possessed a good antibacterial ability.

scholarly journals CHARACTERIZATION OF NICKEL OXIDE NANOPARTICLES SYNTHESIZED VIA RAPID MICROWAVE-ASSISTED ROUTE

2012 ◽  
Vol 05 ◽  
pp. 270-276 ◽  
Author(s):  
D. MOHAMMADYANI ◽  
S.A. HOSSEINI ◽  
S.K. SADRNEZHAAD
Keyword(s):  
Electron Microscope ◽  
Nickel Oxide ◽  
Nano Particles ◽  
X Ray Diffraction ◽  
Nickel Oxide Nanoparticles ◽  
Microwave Assisted ◽  
Nano Powder ◽  
Transmission Electron ◽  
Mean Dimension ◽  
Xrd Patterns

Nickel oxide ( NiO ) nano-particles were produced via a rapid microwave-assisted method. Ni ( OH )2 precursor was obtained by slow drop-wise addition of 0.1M sodium hydroxide to 0.1M nickel nitrate. The mixture was vigorously stirred until the pH reached 7.2. The mixture was then irradiated with microwave to deposit Ni ( OH )2 at an intensified precipitation rate. Drying of the precipitate at 320°C resulted in formation of NiO nano-powder. Mean dimension of this powder was ~30nm according to the images analyzed by transmission electron microscope (TEM) and scanning electron microscope (SEM). X-ray diffraction (XRD) patterns revealed well-crystallized/high-purity nanostructures of the synthesized powder. Microwave utilization increased homogeneity and decreased the mean particle size of the produced NiO powder.

Sign in / Sign up

Export Citation Format

Share Document