Synthesis, Characterization, and Electrochemical Performances of Substituted Layered Transition Metal Oxides. LiM1-yM'yO2. (M=Ni and Co. M'= B and AI)

1996 ◽  
Vol 453 ◽  
Author(s):  
G. A. Nazri ◽  
A. Rougier ◽  
K. F. Kia
Keyword(s):  
Transition Metal Oxides ◽  
Solubility Limit ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Long Cycle Life ◽  
Line Intensities ◽  
Treatment Conditions ◽  
Layered Transition Metal ◽  
Selection Of

AbstractThe synthesis, characterization and electrochemical performances of lithiated nickelate and cobaltate doped with Al and B are reported. The synthesis involves solid state reaction between lithium hydroxide, nickel or cobalt oxides and several sources of aluminum and boron. Careful selection of precursors and heat treatment conditions are required to prepare single phase impurity free samples. X-ray diffraction and Rietveld refinement analysis indicate that the layered structure is preserved upon considerable substitution of aluminum and boron. X-ray diffraction line intensities and positions remained in good agreement with the space group. The IR spectra of the samples indicate formation of compressed CoO6 and NiO6, and elongated LiO6 octahedra. The IR vibrational mode of the LiO6 remains in the 200–300 cm-1 and the vibrational modes of the MO6 expand over 400–650 cm-1. Results of long charge-discharge cycling of the samples as cathode materials in lithium cells showed long cycle life. The capacity of the electrodes upon substitution were reduced almost linearly as the concentration of substitution was increased. The solubility limit for the formation of solid solutions upon substitution of Al and B in LiNiO2 and LiCoO2 was found to be around 25%. Specific capacities of the samples were between 120 to 160 mAh/g depending on the amount of substitution.

Operando powder X-ray diffraction study of P2-Na x Ni0.3Mn0.7O2 cathode material during electrochemical cycling

2018 ◽  
Vol 51 (5) ◽  
pp. 1304-1310 ◽  
Author(s):  
Solveig Kjeldgaard ◽  
Steinar Birgisson ◽  
Anette Gert Kielland ◽  
Bo Brummerstedt Iversen
Keyword(s):  
Cathode Material ◽  
Diffraction Study ◽  
Transition Metal Oxides ◽  
Structural Changes ◽  
Structural Level ◽  
X Ray Diffraction ◽  
X Ray ◽  
Peak Broadening ◽  
Electrochemical Cycling ◽  
Layered Transition Metal

Layered transition metal oxides are of significant interest for applications in sodium-ion batteries. This article reports an operando powder X-ray diffraction study of the cathode material P2-Na x Ni0.3Mn0.7O2 during electrochemical cycling. The structural changes are shown to be reversible over two full cycles, and refinement of sodium occupancies provides insight into the very complex ion movement during battery operation. The sodium loading progresses through a set of metastable compositions showing that the working battery is out of equilibrium on a structural level. Peak broadening caused by stacking faults is observed in the P2 structure at ∼4.0 V, prior to the ∼4.2 V phase transformation from P2 to the `Z' phase

Evidence of Variations in Atomic Distribution in Disordered Mixed Metal Hydroxides

MRS Advances ◽  
2019 ◽  
Vol 4 (33-34) ◽  
pp. 1843-1850
Author(s):  
Wen Rong ◽  
Sarah Stepan ◽  
Rodney D. L. Smith
Keyword(s):  
Transition Metal Oxides ◽  
Iron Ions ◽  
X Ray Diffraction ◽  
Metal Hydroxides ◽  
X Ray ◽  
Mixed Metal ◽  
Apparent Solubility ◽  
Fundamental Understanding ◽  
Double Hydroxides ◽  
Mixed Metal Hydroxides

ABSTRACTNumerous fabrication protocols are known to yield transition metal oxides with structures related to layered double hydroxides, but the effect of fabrication protocol on the uniformity of mixed-metal compositions remain largely unexplored. We have analysed the apparent solubility limits and the structural implications of iron ions in nickel hydroxide lattices for materials prepared by four different fabrication protocols. Opposing shifts in the (100) and (001) reflection in powder X-ray diffraction results revealed a contraction of the nickel lattice upon successful incorporation of iron, with Ni-M distances exhibiting an apparently linear decrease with respect to iron content. This feature revealed the amount of iron incorporated into nickel-based materials to be dependent on fabrication protocol, varying from apparently negligible concentrations to over fifty atomic percent. The dependency of structure on fabrication protocols provides a handle to improve fundamental understanding of catalytically relevant coordination environments.

Facile hydrothermal synthesis of Fe3O4 nanoparticle and effect of crystallinity on performances for supercapacitor

2019 ◽  
Vol 12 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Yue Xu ◽  
Ying Zhang ◽  
Xiaolan Song ◽  
Hanjun Liu
Keyword(s):  
Hydrothermal Method ◽  
Reaction Times ◽  
Amorphous Structure ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Oxide Electrode ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Pseudocapacitive Behavior ◽  
Adsorption Desorption

Fe3O4 nanoparticles were synthesized by a facile hydrothermal method using triethanolamine. Effects of reaction times (2–8[Formula: see text]h) on crystallinity and electrochemical performances of Fe3O4 were investigated. Samples were analyzed by X-ray diffraction, infrared spectroscopy, N2 adsorption–desorption, scanning electron microscope, galvanostatic charge/discharge, and cyclic voltammetry. Results showed that the crystallinity of Fe3O4 was increased with hydrothermal time, and the sample prepared at 2[Formula: see text]h displayed amorphous structure with small grain size and large surface area of 165.0[Formula: see text]m2[Formula: see text]g[Formula: see text]. The sample exhibited typical pseudocapacitive behavior with capacitance of 383.2[Formula: see text]F[Formula: see text]g[Formula: see text] at 0.5 Ag[Formula: see text] in Na2SO3 electrolyte. After 2000 cycles, the capacitance retention of Fe3O4 at 2[Formula: see text]h was recorded as 83.6%, much higher than 26.3% for sample at 8[Formula: see text]h. It indicated that hydrothermal method was an effective approach to obtain amorphous Fe3O4, implying the potential application for preparing metal oxide electrode for supercapacitors.

Structure Maps and Phase Stability in AlTi3 Alloyed with Rare-Earth Elements

1988 ◽  
Vol 133 ◽  
Author(s):  
C. T. Liu ◽  
J. A. Horton ◽  
D. G. Petitifor
Keyword(s):  
Crystal Structure ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Solubility Limit ◽  
Size Factor ◽  
X Ray Diffraction ◽  
Atomic Size ◽  
X Ray ◽  
Dependent Parameter ◽  
Rare Earth Additions

ABSTRACTRare-earth elements including Y, Er and Sc were added to AlTi3 for stabilizing the Ll2 ordered crystal structure, as predicted by the AB3 structure map. The crystal structure and phase composition in the AlTi3 alloys were studied by electron microprobe analysis, X-ray diffraction and TEM. The solubility limit of the rare-earth elements were determined and correlated with the atomic size factor. The results obtained so far indicate that rare-earth additions are unable to change the crystal structure of AlTi3 from DO19 to Ll2. The inability to stabilize the Ll2 structure demonstrates the need to characterize the structure map domains with a further period-dependent parameter.

scholarly journals Solidified Fillings of Nanopores

2005 ◽  
Vol 876 ◽  
Author(s):  
Patrick Huber ◽  
Klaus Knorr
Keyword(s):  
Pore Diameter ◽  
Stacking Faults ◽  
Pore Geometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Medium Length ◽  
Close Packed Structure ◽  
Packed Structure ◽  
Diffraction Patterns ◽  
Selection Of

AbstractWe present a selection of x-ray diffraction patterns of spherical (He, Ar), dumbbell- (N2, CO), and chain-like molecules (n-C9H20, n-C19H40) solidified in nanopores of silica glass (mean pore diameter 7nm). These patterns allow us to demonstrate how key principles governing crystallization have to be adapted in order to accomplish solidification in restricted geometries. 4He, Ar, and the spherical close packed phases of CO and N2 adjust to the pore geometry by introducing a sizeable amount of stacking faults. For the pore solidified, medium-length chainlike n-C19H40 we observe a close packed structure without lamellar ordering, whereas for the short-chain C9H20 the layering principle survives, albeit in a modified fashion compared to the bulk phase.

The Effects of Preparation Conditions And Chemical Composition On CMAS Glass Ceramics With One Step Process

2021 ◽  
Author(s):  
Yuliang Guo ◽  
Huixin Jin ◽  
Yuandan Xiao ◽  
Huahao Song ◽  
Shangjiefu Wang
Keyword(s):  
Solid Waste ◽  
Theoretical Basis ◽  
Chromium Content ◽  
Glass Ceramics ◽  
X Ray Diffraction ◽  
Crystallization Activation Energy ◽  
X Ray ◽  
Preparation Conditions ◽  
Treatment Conditions ◽  
One Step

Abstract Based on the composition of Cr-doped solid waste, other oxides were added to adjust the composition to prepare glass-ceramics with on step composition, and the effect of heat treatment system (including temperature and holding time), chromium content, MnO and Fe2O3 doped on the crystallization and physical properties of glass-ceramics was studied. The samples were characterized by X-ray diffraction, differential thermal analysis and scanning electron microscopy. The results show that the best treatment conditions are 1090 ℃ for 4h, and the amount of dissolved chromium reaches 5%. The main crystallization phase is diopside and anorthite. The hardness and chemical stability of the material were measured. The doping of MnO and Fe2O3 increases the crystallization activation energy of glass ceramics, and makes the crystal phase more uniform as the SEM results. This experiment provides a theoretical basis for the preparation of CMAS glass ceramics from chromium containing solid waste.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

scholarly journals Nitrogen, Phosphorus and Sulfur Co-Doped Pyrolyzed Bacterial Cellulose Nanofibers for Supercapacitors

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1912
Author(s):  
Zheng Li ◽  
Yaogang Wang ◽  
Wen Xia ◽  
Jixian Gong ◽  
Shiru Jia ◽  
...  
Keyword(s):  
Bacterial Cellulose ◽  
High Performance ◽  
Electrode Materials ◽  
Cellulose Nanofibers ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Diffraction Patterns ◽  
Nitrogen Phosphorus ◽  
Co Doped

Heteroatom doping is an effective way to raise the electrochemical properties of carbon materials. In this paper, a novel electrode material including nitrogen, phosphorus, and sulfur co-doped pyrolyzed bacterial cellulose (N/P/S-PBC) nanofibers was produced. The morphologies, structure characteristics and electrochemical performances of the materials were investigated by Scanning electron microscopy, Fourier transform infrared spectra, X-ray diffraction patterns, X-ray photoelectronic spectroscopy, N2 sorption analysis and electrochemical measurements. When 3.9 atom% of nitrogen, 1.22 atom% of phosphorus and 0.6 atom% of sulfur co-doped into PBC, the specific capacitance of N/P/S-PBC at 1.0 A/g was 255 F/g and the N/P/S-PBC supercapacitors’ energy density at 1 A/g was 8.48 Wh/kg with a power density of 489.45 W/kg, which were better than those of the N/P-PBC and N/S-PBC supercapacitors. This material may be a very good candidate as the promising electrode materials for high-performance supercapacitors.

CHARACTERIZATION AND MICRO-RAMAN STUDIES OF Bi2−xPbxSr2Ca2Cu3O10+δ (0 ≤ x ≤ 0.6) SUPERCONDUCTOR

1994 ◽  
Vol 08 (10) ◽  
pp. 591-603
Author(s):  
U. SINHA ◽  
S. SATHAIAH ◽  
R. N. SONI ◽  
H. D. BIST ◽  
S. C. MATHUR ◽  
...  
Keyword(s):  
Ac Susceptibility ◽  
Solubility Limit ◽  
Dc Resistivity ◽  
Apical Oxygen ◽  
X Ray Diffraction ◽  
Phonon Modes ◽  
X Ray ◽  
Percentage Volume ◽  
Pb Substitution ◽  
Scanning Electron

The X-ray diffraction (XRD), ac susceptibility, dc resistivity, and scanning electron microscopy (SEM) measurements on Bi 2−x Pb x Sr 2 Ca 2 Cu 3 O 10+δ (x = 0.0, 0.2, 0.4, and 0.6) superconductors have been correlated with the Raman scattering studies. Remarkable increases in the transition temperature and percentage volume of high T c phase are found till x = 0.4. Raman spectra also reveal dramatic changes at x = 0.4 in the phonon modes at 625 and 460 cm −1 associated with oxygen vibrations in BiO plane and apical oxygen of CuO 5 pyramid, respectively. The observed changes have been attributed to the phenomenon of oxygen redistribution among various layers. Optimum solubility limit of Pb substitution is found to be x = 0.4.

scholarly journals Petrographic and Chemical–Mineralogical Characterization of Mortars from the Cistern at Amaiur Castle (Navarre, Spain)

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 311 ◽  
Author(s):  
Graciela Ponce-Antón ◽  
Maria Cruz Zuluaga ◽  
Luis Angel Ortega ◽  
Juantxo Agirre Mauleon
Keyword(s):  
Organic Additive ◽  
X Ray Diffraction ◽  
Mineralogical Characterization ◽  
X Ray ◽  
Rock Fragments ◽  
Application Techniques ◽  
Aggregate Nature ◽  
Specific Construction ◽  
Selection Of

Mortars from the cistern in Amaiur Castle (Navarre, Spain) were analysed to assess the mortar manufacturing process and application techniques. To this end, optical microscopy, scanning electron microscopy (SEM), thermogravimetric analysis, X-ray fluorescence (XRF), X-ray diffraction (XRD), Raman microspectroscopy, and Fourier transform infrared spectroscopy (FTIR) were performed. The study of both structural and plaster mortars from Amaiur Castle cistern show patterns/rules in the mortar manufacture according to the specific construction requirements. A multilayer application technique was used for the construction of the cistern tank. Deliberate selection of the aggregate nature and grading contributed to mortar impermeability. Ceramic and silico-aluminous rock fragments were used as aggregates in the cistern tank to confer hydraulicity to the mortars, instead of carbonated aggregates as used in the vault. Aluminosilicated phases present in the aggregates led to the formation of amesite, which is a magnesium aluminosilicate hydrate (M-A-S-H) phase conferring hydraulicity to the mortar. Two types of additives were identified in the outer pigmented layer of plaster. Beeswax was the identified organic additive used to improve the impermeability of mortar, while hematite was the identified inorganic additive giving rise to the reddish colour of the layer.

Sign in / Sign up

Export Citation Format

Share Document