Molten Salt Combustion Synthesis of LiMn2O4 at 600°C: the Effect of Calcination Time

2011 ◽  
Vol 230-232 ◽  
pp. 457-460 ◽  
Author(s):  
Gui Yang Liu ◽  
Jun Ming Guo ◽  
Bao Sen Wang ◽  
Ying He
Keyword(s):  
Electrochemical Performance ◽  
Molten Salt ◽  
Single Phase ◽  
Combustion Method ◽  
Molar Ratio ◽  
Performance Tests ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
Capacity Retention ◽  
X Ray

Spinel LiMn2O4 were prepared by a molten salt combustion method at 600°C. The phase composition of the products was investigated by X-ray diffraction (XRD), and the electrochemical performance was tested by a coin-type self battery. XRD results presented that the purity and the crystallinity of the products increased with extending calcining time. Single phase LiMn2O4 could be prepared at 600°C for 6 and 12h. The ratio of lithium/manganese also affected the phase compositions of the products. The purity and crystallinity of the product with the molar ratio of Li/Mn=1.1/2 were higher than these of the product with the molar ratio of Li/Mn=1.05/2. The performance tests indicated that the electrochemical performance of the product prepared at 600°C for 6h is the best. The initial discharge capacity was 112.8mAh/g, and after 20 cycles, the capacity retention is 81.8%. The product with Li/Mn=1.1/2 had better electrochemical performance than the product with Li/Mn=1.05/2.

LiNi0.5Mn1.5O4 Prepared by a Solution Combustion Synthesis at Different Temperatures

2011 ◽  
Vol 186 ◽  
pp. 3-6
Author(s):  
Gui Yang Liu ◽  
Jun Ming Guo ◽  
Bao Sen Wang
Keyword(s):  
Electrochemical Performance ◽  
Single Phase ◽  
Solution Combustion Synthesis ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
Solution Combustion Method ◽  
X Ray ◽  
Different Temperatures ◽  
Micro Morphology

LiNi0.5Mn1.5O4 powders have been prepared by a solution combustion method at 300-800oC. X-ray diffraction (XRD) and scanning electric microscope (SEM) were used to determine the phase composition and micro morphology of the products. The results indicate that the products with single phase LiNi0.5Mn1.5O4 can be obtained at 400-600oC. The electrochemical performance was tested by a coin-type battery. The product prepared at 600oC has the best electrochemical performance. The maximum capacity of the product prepared at 600oC is 135mAh/g at the current density of 30mA/g, and after 30 cycles, the capacity fades little.

Cathode Material Li [Li0.2 Mn0.44Ni0.18Co0.18]O2 Synthesized by Molten Salt Method

2013 ◽  
Vol 690-693 ◽  
pp. 981-984
Author(s):  
Guang Xin Fan ◽  
Hui Lian Li ◽  
Shu Pu Dai ◽  
Chuan Xiang Zhang ◽  
Xue Mao Guan ◽  
...  
Keyword(s):  
Molten Salt ◽  
Specific Area ◽  
Constant Current ◽  
Molar Ratio ◽  
Molten Salt Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Structures And Properties ◽  
Constant Current Charge

In this paper, LiOH·H2O and Li2CO3, which were widely used in industry and (Mn0.533Co0.233Ni0.233) (OH)2prepared by ourselves selected as starting materials, series materials of lithium-rich layered material Li [Li0.2Mn0.44Ni0.18Co0.18]O2were obtained by a molten salt method. Their structures and properties of the materials were investigated by X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) and constant current charge/discharge methods. The effects of different LiOH and Li2CO3molar ratios on the Li [Li0.2Mn0.44Ni0.18Co0.18]O2structures and properties were characterized. The results of the experiments indicate that The structures of the material such as crystal structure, the specific area, particle size distribution, tap densities were controlled by adjusting the proportion of the two lithium sources. Forthermore , when the molar ratio of LiOH and Li2CO3was 3:7, the maximum discharge capacity (214.77 mAhg-1) of the cathode was obtained.

Synthesis of Ti3Si0.4Al0.8C1.8 Solid Solution

2008 ◽  
Vol 368-372 ◽  
pp. 995-997
Author(s):  
Cui Wei Li ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Shi Bo Li ◽  
Zhi Li Zhang
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Single Phase ◽  
Lattice Parameters ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Scanning Electron

In this study, free Ti/Si/Al/C powder mixtures with molar ratio of 3:0.4:0.8:1.8 were heated in Argon with various schedules, in order to reveal the possibility for the synthesis of Ti3Si0.4Al0.8C1.8 solid solution powder. X-ray diffraction (XRD) was used for the evaluation of phase identities of the powder after different treatments. Scanning electron microscopy (SEM) was used to observe the morphology of the Ti3Si0.4Al0.8C1.8 solid solution. XRD results showed that predominantly single phase samples of Ti3Si0.4Al0.8C1.8 was prepared after heating at 1400oC for 5 min in Argon and the lattice parameters of Ti3Si0.4Al0.8C1.8 lay between those of Ti3SiC2 and Ti3AlC2.

scholarly journals Structural and magnetic properties of mechanochemically synthesized nanosized yttrium titanate

2012 ◽  
Vol 66 (3) ◽  
pp. 309-315 ◽  
Author(s):  
Tanja Barudzija ◽  
Alexey Gusev ◽  
Dragana Jugovic ◽  
Milena Marinovic-Cincovic ◽  
Miroslav Dramicanin ◽  
...  
Keyword(s):  
Quantum Interference ◽  
Single Phase ◽  
High Energy ◽  
Argon Atmosphere ◽  
Molar Ratio ◽  
Superconducting Quantum Interference Device ◽  
X Ray Diffraction ◽  
X Ray ◽  
The Mean ◽  
First Time

Nanosized perovskite YTiO3 with the mean crystallite size of 18 nm was synthesized for the first time by mechanochemical treatment. The mechanochemical solid state reaction between commercial Y2O3 powder and mechanochemically synthesized TiO powder in molar ratio 0.5:1 was completed for 3 h in a high-energy planetary ball mill in argon atmosphere. The heating in vacuum at 1150 ?C for 12 h transforms nanosized YTiO3 to a well-crystallized single-phase perovskite YTiO3. Both samples were characterized by X-ray diffraction (XRD) and thermogravimetric (TGA/DTA) analyses, as well as superconducting quantum interference device magnetometer (SQUID) measurements.

The Effect of Calcination Time on Crystallite Size of LiMn1.8Ni0.2O4 Cathode Materials

2020 ◽  
Vol 307 ◽  
pp. 136-140
Author(s):  
Michelle Matius ◽  
Norlida Kamarulzaman ◽  
Mohd Sufri Mastuli ◽  
Nor Syamilah Syamimi Mohd Abdillih ◽  
Kelimah Elong
Keyword(s):  
Crystallite Size ◽  
Cathode Materials ◽  
Single Phase ◽  
Small Mass ◽  
Li Ion Batteries ◽  
X Ray Diffraction ◽  
Calcination Time ◽  
X Ray ◽  
Li Ion ◽  
Materials Used

Spinel LiMn2O4 is one of the promising cathode materials used in commercial Li-ion batteries. In this study, Ni was partially substituted in order to give the material LiMn1.8Ni0.2O4, which was successfully synthesized using a self-propagating combustion (SPC) method. Results from Simultaneous Thermogravimetric Analysis (STA) show the small mass loss about 4.6%. The precursor then was calcined at temperature of 800 °C for 24 h, 48 h and 72 h. X-Ray Diffraction (XRD) confirms that the final products are pure and single phase with no impurities present. The morphology and crystallite size of pure samples are examined using Field Emission Scanning Electron Microscope (FESEM). The result shows that all the materials consist of crystalline particles with smooth surface and polyhedral shaped materials.

Preparation of Forsterite by Solid State Synthesis Process and its Dielectric Properties

2012 ◽  
Vol 534 ◽  
pp. 110-113 ◽  
Author(s):  
Fei Shi ◽  
Peng Cheng Du ◽  
Jing Xiao Liu ◽  
Ji Wei Wu ◽  
Chun Yuan Luo
Keyword(s):  
Dielectric Properties ◽  
Solid State ◽  
Single Phase ◽  
Raw Materials ◽  
Magnesium Carbonate ◽  
Solid State Synthesis ◽  
Molar Ratio ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
X Ray

Using basic magnesium carbonate (Mg(OH)2•4MgCO3•6H2O) and SiO2 as raw materials, forsterite (Mg2SiO4) was prepared by solid state synthesis process. The optimal process for synthesizing Mg2SiO4 was obtained by adjusting Mg/Si molar ratio and sintering temperature. The crystal phase of the obtained Mg2SiO4 powder was determined by X-ray diffraction (XRD). The results indicate that the single-phase Mg2SiO4 powder can be obtained when the mixtures with Mg/Si molar ratio of 2.05～2.01 were sintered at 1350°C for 3h in the air. The as-prepared Mg2SiO4 ceramic samples which were sintered at 1300～1360°C showed better dielectric properties with εr=7.4 and tanδ =7.5×10-4.

Combustion Synthesis of Long Afterglow luminescent Materials Sr2-xCaxMgSi2O7:Eu2+,Dy3+

2011 ◽  
Vol 287-290 ◽  
pp. 213-216 ◽  
Author(s):  
Yong Qiang Zhou ◽  
Yi Guang Tian ◽  
He Shan Ying
Keyword(s):  
Single Phase ◽  
Combustion Method ◽  
Process Conditions ◽  
Luminescent Materials ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
X Ray ◽  
Long Afterglow ◽  
Long Wave ◽  
Luminescence Performance

Long afterglow luminescent materials Sr2-xCaxMgSi2O7:Eu2+,Dy3+ （x=0-1.955）was synthesized by combustion method and characterized by X－ray diffraction,fluorescencespectrum and so on. Its preparing process conditions,the effect of Ca2+ replacing Sr2+ on its Luminescent performance were discussed. The results show it has a single phase and foamy structure,which is easy to be grinded into superfine powders. Its Luminescent property is importantly affected by water dosage(R= nH2O /nTEOS), reducer dosage (H=nreducer /nnitrate), gel grain dosage , gel grain size, arousing-burning temperature and burning time. Its best preparing process conditions are determined. A small quantity of Ca2+ replacing Sr2+ can raise its luminescence performance. Increasing Ca2+ content, its emission peak gradually wave to the long wave traverse, its luminous colors change from blue to yellow. Compared with the sample synthesized by high temperature solid reaction,the emission peaks of the sample synthesized by combustion method distinctly take place red shift.

scholarly journals Thermal Analysis of High Entropy Rare Earth Oxides

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3141 ◽  
Author(s):  
Sergey V. Ushakov ◽  
Shmuel Hayun ◽  
Weiping Gong ◽  
Alexandra Navrotsky
Keyword(s):  
Thermal Analysis ◽  
Rare Earth ◽  
Single Phase ◽  
Liquidus Surface ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
Solution Combustion ◽  
X Ray ◽  
High Entropy ◽  
Rare Earth Sesquioxides

Phase transformations in multicomponent rare earth sesquioxides were studied by splat quenching from the melt, high temperature differential thermal analysis and synchrotron X-ray diffraction on laser-heated samples. Three compositions were prepared by the solution combustion method: (La,Sm,Dy,Er,RE)2O3, where all oxides are in equimolar ratios and RE is Nd or Gd or Y. After annealing at 800 °C, all powders contained mainly a phase of C-type bixbyite structure. After laser melting, all samples were quenched in a single-phase monoclinic B-type structure. Thermal analysis indicated three reversible phase transitions in the range 1900–2400 °C, assigned as transformations into A, H, and X rare earth sesquioxides structure types. Unit cell volumes and volume changes on C-B, B-A, and H-X transformations were measured by X-ray diffraction and consistent with the trend in pure rare earth sesquioxides. The formation of single-phase solid solutions was predicted by Calphad calculations. The melting point was determined for the (La,Sm,Dy,Er,Nd)2O3 sample as 2456 ± 12 °C, which is higher than for any of constituent oxides. An increase in melting temperature is probably related to nonideal mixing in the solid and/or the melt and prompts future investigation of the liquidus surface in Sm2O3-Dy2O3, Sm2O3-Er2O3, and Dy2O3-Er2O3 systems.

Study of Sol-Gel Auto-Combustion Method Prepare Ni0.6-xZn0.4MgxFe2O4

2012 ◽  
Vol 463-464 ◽  
pp. 1052-1056
Author(s):  
Ai Xiang Zeng ◽  
Jun Yuan
Keyword(s):  
Crystal Structure ◽  
Zinc Ferrite ◽  
Single Phase ◽  
Sol Gel ◽  
Combustion Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Zinc ◽  
Auto Combustion ◽  
Scanning Electron

Ni0.6-xZn0.4MgxFe2O4were synthesized by sol-gel auto-combustion method with Zn(NO3.) 2 •6H2O. , Ni(NO3.) )2•6H2O. , Mg(NO3.) )2•6H2O. , Fe(NO3.) )3•9H2O. , COOO2. and NH3•H2O. X-ray diffraction (XRD) analysises show that the sample is single phase and the doping of magnesium makes no difference to nickel-zinc ferrite’s crystal structure; nickel-zinc ferrite has formed after auto-combustion. Scanning electron microscope analysises show that after sintered the sample’s size is more even and the doping of magnesium makes the size smaller and more even too.

scholarly journals Synthesis and electrochemical performance of Li2Co1− x M x PO4F (M = Fe, Mn) cathode materials

2013 ◽  
Vol 4 ◽  
pp. 860-867 ◽  
Author(s):  
Nellie R Khasanova ◽  
Oleg A Drozhzhin ◽  
Stanislav S Fedotov ◽  
Darya A Storozhilova ◽  
Rodion V Panin ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Single Phase ◽  
High Energy ◽  
Initial Discharge Capacity ◽  
X Ray Diffraction ◽  
Energy Materials ◽  
X Ray ◽  
High Energy Materials ◽  
Initial Discharge ◽  
Scanning Electron

In the search for high-energy materials, novel 3D-fluorophosphates, Li2Co1− x Fe x PO4F and Li2Co1− x Mn x PO4F, have been synthesized. X-ray diffraction and scanning electron microscopy have been applied to analyze the structural and morphological features of the prepared materials. Both systems, Li2Co1− x Fe x PO4F and Li2Co1− x Mn x PO4F, exhibited narrow ranges of solid solutions: x ≤ 0.3 and x ≤ 0.1, respectively. The Li2Co0.9Mn0.1PO4F material demonstrated a reversible electrochemical performance with an initial discharge capacity of 75 mA·h·g−1 (current rate of C/5) upon cycling between 2.5 and 5.5 V in 1 M LiBF4/TMS electrolyte. Galvanostatic measurements along with cyclic voltammetry supported a single-phase de/intercalation mechanism in the Li2Co0.9Mn0.1PO4F material.

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