New Iron Oxide Positive Active Material for Lithium Secondary Batteries

1998 ◽  
Vol 548 ◽  
Author(s):  
K. Amine ◽  
H. Yasuda ◽  
M. Yamachi
Keyword(s):  
Iron Oxide ◽  
Electrode Material ◽  
Photoelectron Spectroscopy ◽  
Active Material ◽  
High Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lithium Secondary Batteries ◽  
Divalent State ◽  
V Region

ABSTRACTBeta-iron oxy-hydroxide, which exhibits a (2×2) tunnel-type structure similar to that of (α-MnO2, was found to intercalate reversibly lithium in the tunnels. This material exhibits three voltage plateaus at 2.3, 1.5 and 0.7 V and has an over all discharge capacity of 1100 mAh/g. When cycling in the 2–V region, the material exhibits high capacity of 275 mAh/g and very good cyclic reversibility. X-ray photoelectron spectroscopy (XPS) of the discharged material showed that iron is reduced to the divalent state, and the lithium incorporated in the tunnels is purely ionic. This result explains the good reversibility of this electrode material. When discharged to 0.5 V, however, the structure of the material collapsed, and metallic iron was detected in the X-ray diffraction pattern.

scholarly journals Spherical Sb Core/Nb2O5-C Double-Shell Structured Composite as an Anode Material for Li Secondary Batteries

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1999
Author(s):  
Hyungeun Seo ◽  
Kyungbae Kim ◽  
Jae-Hun Kim
Keyword(s):  
Volume Change ◽  
Photoelectron Spectroscopy ◽  
Active Material ◽  
High Capacity ◽  
Reversible Capacity ◽  
Cycle Performance ◽  
Core Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Improved Performance

Antimony (Sb)-based materials are considered to be attractive for use in Li secondary battery anodes because of their high capacity. However, their huge volume change during Li insertion-extraction cycling limits their cycle performance. The Sb-active material can be combined with intercalation-based active materials to address these issues. In this study, spherical Sb core/Nb2O5 shell structured composite materials were synthesized through a simple solvothermal process and a carbon coating was simultaneously added during heat treatment using a naphthalene precursor. The resulting double-shelled materials were characterized with X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and electron microscopy. The electrochemical test results showed that a reversible capacity of more than 450 mAh g−1 was retained after 100 cycles. This improved performance is ascribed to the double-shelled structure. The large volume change of the nano-sized Sb core material was alleviated by the double-shelled structure, which consisted of crystalline orthorhombic Nb2O5 and amorphous carbon. The shell materials also aided rapid charge transport.

Formation of maghemite nanoparticles in bismuth telluride materials containing iron

2010 ◽  
Vol 25 (10) ◽  
pp. 2042-2046
Author(s):  
R.M. Catchings ◽  
A.N. Thorpe ◽  
J.R. Grant ◽  
R. Douglas ◽  
C. Viragh ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Bismuth Telluride ◽  
Photoelectron Spectroscopy ◽  
Chemical Method ◽  
Oxide Nanoparticles ◽  
Maghemite Nanoparticles ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Wet Chemical

Bismuth telluride (Bi2Te3) systems containing 2%, 4%, and 8% of iron were prepared using a low temperature wet chemical method. Iron oxide nanoparticles were formed when the samples were heated in hydrogen at 250 °C for at least six hours. The samples were characterized by x-ray diffraction, magnetization, magnetic susceptibility, x-ray photoelectron spectroscopy, Mössbauer spectroscopy, and wet chemical analysis measurements. The nanoparticles of iron oxide were identified as γ-Fe2O3 with a particle size of ˜5 nm.

scholarly journals Phosphate adsorption onto bagasse iron oxide biochar: Parameter optimization, kinetic analysis, and study of mechanism

BioResources ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. 1335-1357
Author(s):  
Qing Zhang ◽  
Yan-mei Ding ◽  
Lin Lu ◽  
Jing-xi Li ◽  
Mei-na Liang ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Photoelectron Spectroscopy ◽  
Phosphate Adsorption ◽  
Phosphorus Concentration ◽  
X Ray Diffraction ◽  
Phosphorus Adsorption ◽  
X Ray ◽  
Bet Specific Surface Area ◽  
Ph Range

This study combined chemical ultrasonic modifications and microwave oven heating to prepare a novel adsorbent, bagasse iron oxide biochar, (BIBC) to remove phosphate from aqueous solutions. The characterization of BIBC was made by energy dispersive spectrometry (EDS), Brunauer–Emmett–Teller (BET), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) analyses, and the mechanism of phosphorus adsorption on BIBC was researched by adsorption batch experiments with emphasis on pH, dosages of BIBC, initial phosphorus concentration, and adsorption time. The BIBC’s BET specific surface area and pore volumes were 81.94 m2 g−1 and 26.74 cm3 g−1, respectively. The pH for the optimal phosphorus adsorption by BIBC ranged from 5.0 to 7.0. The maximum adsorption capacities of phosphorus (according to the Langmuir model) were 3.62, 4.06, and 4.32 mg g-1 at temperatures of 25, 35, and 45 °C, respectively. Electrostatic interaction, surface adsorption of phosphorus on BIBC, and ion exchange were the main mechanisms of phosphorus adsorption. According to XPS results, Fe2p was involved in the adsorption reaction. The adsorption of phosphorus by BIBC is considered to be mainly chemical adsorption. The BIBC was stable under a pH range from 4.0 to 10.0 and secondary pollution did not result.

Charge properties of red Argentine soils as an indicator of iron oxide/clay associations

Soil Research ◽  
2001 ◽  
Vol 39 (2) ◽  
pp. 423 ◽  
Author(s):  
R. M. Torres Sánchez ◽  
M. Okumura ◽  
R. C. Mercader
Keyword(s):  
Iron Oxide ◽  
Iron Oxides ◽  
Photoelectron Spectroscopy ◽  
Electron Probe ◽  
Surface Coverage ◽  
Oxide Coating ◽  
Point Of Zero Charge ◽  
X Ray Diffraction ◽  
X Ray ◽  
North Eastern

The order of the relative degree of iron oxide coating of 4 samples of red soils from north-eastern Argentina was established using the point of zero charge (PZC), yielded by potentiometric titration, and the isoelectric point (IEP), obtained from the diffusion potential. When PZC is different from IEP, the relative fraction of apparent surface coverage could be assessed from the IEP. The results obtained by the application of X-ray diffraction, scanning electron microscopy, electron probe microanalysis, X-ray photoelectron spectroscopy, Mössbauer spectroscopy, and specif ic surface area, although essential to characterise the samples, did not allow us to determine the degree of iron oxide coating. Our findings show that the order of this degree is opposite to the order of the ratio of the amount of free iron oxides to that of clay in iron oxides/clay mixtures.

The Preparation of Nanosized Iron Oxide Using Hydrolysis Enhanced by CuO and their Characterization

2013 ◽  
Vol 320 ◽  
pp. 275-280 ◽  
Author(s):  
Li Hua Lin ◽  
Jian Li ◽  
Long Long Chen
Keyword(s):  
Iron Oxide ◽  
Photoelectron Spectroscopy ◽  
Experimental Results ◽  
Precipitation Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Weakly Magnetic ◽  
Nanosized Oxide ◽  
Nanosized Iron

By adding CuO into heated Fe (NO3)3 aqueous solution, a precipitation reaction takes place to form nanosized iron oxide. The product obtained were characterized by transmission electron microscopy (TEM), vibrating sample magnetized (VSM), X-ray diffraction (XRD), energy disperse X-ray spectroscopy (EDX) and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the product is weakly magnetic nanoclusters based on smaller ferrihydrite Fe5O7(OH)·4H2O nanocrystallites. The nanoclusters are of about 40 nm size and absorbed by Fe (NO3)3. The experimental results are attributed to the Fe (NO3)3 hydrolysis reaction being enhanced by CuO as hydrolyte. A new route is proposed for the preparation of nanosized oxide using hydrolysis enhanced.

Oxygen Gettering Effect During the Reactive Evaporation of Manganese Oxide Films

1999 ◽  
Vol 14 (4) ◽  
pp. 1653-1657 ◽  
Author(s):  
Masaaki Isai ◽  
Katsuma Yamaguchi ◽  
Haruhiko Iyoda ◽  
Hiroshi Fujiyasu ◽  
Yasumitsu Ito
Keyword(s):  
Manganese Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxide Films ◽  
Rapid Change ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lithium Secondary Batteries ◽  
Reactive Evaporation ◽  
Mn Oxide

Manganese oxide films for lithium secondary batteries were prepared using a reactive evaporation method. Mn was evaporated from a molybdenum boat by resistive heating and deposited on a glass slide under oxygen atmosphere. These films were examined with x-ray photoelectron spectroscopy (XPS) and x-ray diffraction. The Mn oxide films with a wide valency of Mn were prepared in this study. A rapid change of the back pressure was found as the deposition of Mn was started. This implies that Mn atoms start to react with O2. This means that in situ detection of reactive evaporation process can be utilized.

A low cost synthesis method for functionalised iron oxide nanoparticles for magnetic hyperthermia from readily available materials

2014 ◽  
Vol 175 ◽  
pp. 83-95 ◽  
Author(s):  
Joseph C. Bear ◽  
Bin Yu ◽  
Cristina Blanco-Andujar ◽  
Paul D. McNaughter ◽  
Paul Southern ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Aqueous Media ◽  
Synthesis Method ◽  
Magnetic Hyperthermia ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Street ◽  
Fatty Acid Precursor

The synthesis of iron oxide nanocrystals from reagents taken from high street sources using thermal decomposition of an iron–fatty acid precursor in a high boiling point solvent in the presence of surfactants is presented. The nanocrystals were characterised using a variety of techniques including: electron microscopy, X-ray dispersive spectroscopy, infrared spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and magnetometry. Thermogravimetric analysis (TGA) is also used to compare the decomposition behaviour of iron oleate and iron palmitate, our nanoparticle precursors. The nanoparticles also exhibit shape anisotropy when prepared under optimum conditions. We show that these nanoparticles have potential in magnetic hyperthermia after transfer to aqueous media via an amphiphilic polymer.

Hydrothermal Prepared α-MnO2 Nanowire and its Supercapacitor Electrochemical Performances

2014 ◽  
Vol 953-954 ◽  
pp. 1040-1044
Author(s):  
Yang Li ◽  
Jing Li ◽  
Hua Qing Xie
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electrode Material ◽  
Scan Electron Microscopy ◽  
Active Material ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Potential Alternative

α-MnO2nanowire was prepared by hydrothermal method. The structure of as-prepared manganese oxide demonstrated tetragonal crystalline in X-ray diffraction pattern. Scan electron microscopy (SEM) and Transmission electron microscopy (TEM) revealed the nanowire morphology of as-prepared α-MnO2. The band gap of α-MnO2was estimated at about 2.06 eV via UV-vis spectrum. As the electrode active material for supercapacitor, the electrochemical specific capacitance of α-MnO2nanowire achieved 156.5 F/g, which possessed typical capacitive behaviors and good cycling stabilities. Based on the preferable electrochemical performances, as-synthesized α-MnO2nanowire may be a potential alternative as electrode material for supercapacitor.

Red-emitting AlN:Mn2+ phosphors prepared by combustion synthesis

2015 ◽  
Vol 08 (02) ◽  
pp. 1550025 ◽  
Author(s):  
Zhongqi Shi ◽  
Yongyong Zou ◽  
Ruifeng Jing ◽  
Kuo Zhang ◽  
Guanjun Qiao ◽  
...  
Keyword(s):  
Combustion Synthesis ◽  
Photoelectron Spectroscopy ◽  
Synthesis Method ◽  
Element Composition ◽  
Second Phase ◽  
X Ray Diffraction ◽  
Sem Images ◽  
X Ray ◽  
Ultraviolet Excitation ◽  
Divalent State

Red-emitting Mn 2+-doped AlN ( AlN:Mn 2+) phosphors were successfully prepared by a highly effective combustion synthesis method. The phase purity, morphology, element-composition and luminescence properties of the synthesized phosphors were investigated. X-ray diffraction (XRD) results show that the Mn 2+-doped into the AlN host did not induce a second phase and distort the structure significantly. Scanning electron microscopy (SEM) images display that the phosphors have an irregular shape with a particle size in the range of 1–5 μm. X-ray photoelectron spectroscopy (XPS) spectrum indicates that Mn ions are divalent state. The synthesized AlN:Mn 2+ phosphors exhibit a strong red emission centered at ~ 600 nm, which is ascribe to the 4T1(4G)–6A1(6S) transition of Mn 2+ under ultraviolet excitation. The emission intensity reaches its maximum when Mn 2+-doped concentration is 3 mol%.

Investigation of the Effect of Uv-Assisted Oxidation and Nitridation of Hafnium Metal Films

2003 ◽  
Vol 780 ◽  
Author(s):  
C. Essary ◽  
V. Craciun ◽  
J. M. Howard ◽  
R. K. Singh
Keyword(s):  
Uv Radiation ◽  
Photoelectron Spectroscopy ◽  
Grazing Angle ◽  
X Ray Diffraction ◽  
Metal Thin Films ◽  
X Ray ◽  
Force Microscopy ◽  
Si Substrates ◽  
Atomic Force ◽  
Silicon Interface

AbstractHf metal thin films were deposited on Si substrates using a pulsed laser deposition technique in vacuum and in ammonia ambients. The films were then oxidized at 400 °C in 300 Torr of O2. Half the samples were oxidized in the presence of ultraviolet (UV) radiation from a Hg lamp array. X-ray photoelectron spectroscopy, atomic force microscopy, and grazing angle X-ray diffraction were used to compare the crystallinity, roughness, and composition of the films. It has been found that UV radiation causes roughening of the films and also promotes crystallization at lower temperatures.Furthermore, increased silicon oxidation at the interface was noted with the UVirradiated samples and was shown to be in the form of a mixed layer using angle-resolved X-ray photoelectron spectroscopy. Incorporation of nitrogen into the film reduces the oxidation of the silicon interface.

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