Microwave Synthesis of LiMPO4: Electrochemical Performance Dependence on Microwave Synthesis Conditions and Particle Size

In the paper, the particle morphology is considered and the slices of phase diagrams of nanosystems agreeable to the synthesis conditions are constructed according to the data obtained earlier by authors, as well as new results of the study of nanostructured Fe-Co, Fe-Ni, Co-Ni, Fe-Co-Ni, Fe-Pt, Cu-Ni and Ni-Cd powders. It is found that all considered polymetallic systems have common nature of the particle size spatial organization, i.e., 7-20 nm nanocrystals (for different systems) form highly compact aggregates (40-100 nm) which put together into loose porous agglomerates (up to 200-250 nm) and then into unconsolidated micron size formation of cloud type. It is classified uncovered features of nanostructured polymetallic phase diagrams in comparison with phase diagrams of bulk systems. Magnetic properties of nanosystems are studied.

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Probing the Effect of High Energy Ball Milling on the Structure and Properties of LiNi1/3Mn1/3Co1/3O2 Cathodes for Li-Ion Batteries

Journal of Electrochemical Energy Conversion and Storage ◽

10.1115/1.4034755 ◽

2016 ◽

Vol 13 (3) ◽

Cited By ~ 5

Author(s):

Malcolm Stein ◽

Chien-Fan Chen ◽

Matthew Mullings ◽

David Jaime ◽

Audrey Zaleski ◽

...

Keyword(s):

Particle Size ◽

Electrochemical Performance ◽

Crystallite Size ◽

Ball Milling ◽

Lithium Ion ◽

High Energy ◽

Li Ion Batteries ◽

Structure And Properties ◽

Transfer Resistance ◽

Li Ion

Particle size plays an important role in the electrochemical performance of cathodes for lithium-ion (Li-ion) batteries. High energy planetary ball milling of LiNi1/3Mn1/3Co1/3O2 (NMC) cathode materials was investigated as a route to reduce the particle size and improve the electrochemical performance. The effect of ball milling times, milling speeds, and composition on the structure and properties of NMC cathodes was determined. X-ray diffraction analysis showed that ball milling decreased primary particle (crystallite) size by up to 29%, and the crystallite size was correlated with the milling time and milling speed. Using relatively mild milling conditions that provided an intermediate crystallite size, cathodes with higher capacities, improved rate capabilities, and improved capacity retention were obtained within 14 μm-thick electrode configurations. High milling speeds and long milling times not only resulted in smaller crystallite sizes but also lowered electrochemical performance. Beyond reduction in crystallite size, ball milling was found to increase the interfacial charge transfer resistance, lower the electrical conductivity, and produce aggregates that influenced performance. Computations support that electrolyte diffusivity within the cathode and film thickness play a significant role in the electrode performance. This study shows that cathodes with improved performance are obtained through use of mild ball milling conditions and appropriately designed electrodes that optimize the multiple transport phenomena involved in electrochemical charge storage materials.

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Microwave Synthesis of Silicon Carbide Nano Powders with Silicon and Carbon

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.602-603.118 ◽

2014 ◽

Vol 602-603 ◽

pp. 118-121

Author(s):

You Jun Lu ◽

Hong Fang Shen ◽

Sheng Wei Guo

Keyword(s):

Silicon Carbide ◽

Particle Size ◽

Microwave Heating ◽

Chemical Reaction ◽

Crystalline Phase ◽

Microwave Synthesis ◽

Time Effects ◽

Xrd Patterns

Nanosized silicon carbide powders were synthesized from a mixture of silicon and carbon by microwave heating methods. The Result Indicates SiC can be formed at lower temperatures by using the Si-C reaction at 1200°C for 30min. XRD patterns shows that SiC peaks appeared as the only crystalline phase. SEM photo shows the particle size was 100～200 nanometer. At the same time, Effects of chemical reaction of silicon and carbon was researched by mechanical activated microwave synthesis.

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Preparation of La0.75Sr0.25Cr0.5Mn0.5O3-δ Nanometer Powders by Sol-Gel Method and Research about its Electrochemical Performance

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.712-715.257 ◽

2013 ◽

Vol 712-715 ◽

pp. 257-261

Author(s):

Yin Lin Wu ◽

Qing Hui Wang ◽

Ling Wang ◽

Hai Yan Zhao

Keyword(s):

Heat Treatment ◽

Particle Size ◽

Electrochemical Performance ◽

Heat Treatment Temperature ◽

Sol Gel ◽

Treatment Temperature ◽

Preparation Process ◽

Gel Method ◽

Sol Gel Method ◽

Ft Ir

The La0.75Sr0.25Cr0.5Mn0.5O3-δnanometer powders were prepared by citric acid sol-gel method.The samples were characterized by DTA, FT-IR, XRD, TEM techniques. The preparation process, morphology of synthesized powders, the best heat-treatment temperature and the electrochemical performance had been studied. The results show that the spherical nanometer powders can be obtained and the best heat-treatment temperature is 800°C. The particle size is about 30nm and Ea is 0.071 eV.

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Effect of the polymeric coating over Fe3O4 particles used for magnetic separation

Open Chemistry ◽

10.2478/s11532-010-0073-4 ◽

2010 ◽

Vol 8 (5) ◽

pp. 1041-1046 ◽

Cited By ~ 17

Author(s):

Raúl Reza ◽

Carlos Martínez Pérez ◽

Claudia Rodríguez González ◽

Humberto Romero ◽

Perla García Casillas

Keyword(s):

Particle Size ◽

Magnetite Nanoparticles ◽

Average Particle Size ◽

Spherical Shape ◽

Polymeric Coating ◽

Average Particle ◽

Synthesis Conditions ◽

Aging Conditions ◽

Magnetite Particles ◽

Average Size

AbstractIn this work, the synthesis of magnetite nanoparticles by two variant chemical coprecipitation methods that involve reflux and aging conditions was investigated. The influence of the synthesis conditions on particle size, morphology, magnetic properties and protein adsorption were studied. The synthesized magnetite nanoparticles showed a spherical shape with an average particle size directly influenced by the synthesis technique. Particles of average size 27 nm and 200 nm were obtained. When the coprecipitation method was used without reflux and aging, the smallest particles were obtained. Magnetite nanoparticles obtained from both methods exhibited a superparamagnetic behavior and their saturation magnetization was particle size dependent. Values of 67 and 78 emu g−1 were obtained for the 27 nm and 200 nm magnetite particles, respectively. The nanoparticles were coated with silica, aminosilane, and silica-aminosilane shell. The influence of the coating on protein absorption was studied using Bovine Serum Albumin (BSA) protein.

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Eco-friendly microwave-enhanced green synthesis of silver nanoparticles using Aloe vera leaf extract and their physico-chemical and antibacterial studies

Green Processing and Synthesis ◽

10.1515/gps-2017-0039 ◽

2018 ◽

Vol 7 (3) ◽

pp. 231-240 ◽

Cited By ~ 23

Author(s):

Omid Ahmadi ◽

Hoda Jafarizadeh-Malmiri ◽

Naeimeh Jodeiri

Keyword(s):

Particle Size ◽

Silver Nanoparticles ◽

Exposure Time ◽

Leaf Extract ◽

Aloe Vera ◽

Synthesis Conditions ◽

Stabilizing Agents ◽

Microwave Exposure ◽

Mean Particle Size ◽

Vis Spectroscopy

Abstract Silver nanoparticles (AgNPs) were synthesized using Aloe vera leaf extract as both reducing and stabilizing agents via microwave irradiation method. The effects of the microwave exposure time and the amount of AgNO3 solution on the mean particle size and concentration of the synthesized AgNPs solution were investigated using response surface methodology. The synthesized AgNPs were characterized by transmission electron microscopy, UV-Vis spectroscopy, and dynamic light scattering. Well-dispersed and spherically fabricated AgNPs with mean particle size (46 nm) and maximum concentration (64 ppm) and zeta potential (+15.5 mV), were obtained at optimal synthesis conditions, using 9 ml of AgNO3 (1 mm) and 0.1 ml of Aloe vera extract during microwave exposure time of 360 s. The antibacterial activity of the synthesized AgNPs was tested using Escherichia coli and Staphylococcus aureus bacteria and the obtained results indicated their significant inhibitory effects against these two Gram-negative and Gram-positive bacteria.

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Energy-Density Improvement in Li-Ion Rechargeable Batteries Based on LiCoO2 + LiV3O8 and Graphite + Li-Metal Hybrid Electrodes

Materials ◽

10.3390/ma12122025 ◽

2019 ◽

Vol 12 (12) ◽

pp. 2025

Author(s):

Ki Yoon Bae ◽

Sung Ho Cho ◽

Byung Hyuk Kim ◽

Byung Dae Son ◽

Woo Young Yoon

Keyword(s):

Energy Density ◽

Electrochemical Performance ◽

Discharge Capacity ◽

Electrochemical Impedance ◽

Rechargeable Batteries ◽

Battery System ◽

X Ray ◽

Metal Anode ◽

Synthesis Conditions ◽

A Cell

We developed a novel battery system consisting of a hybrid (LiCoO2 + LiV3O8) cathode in a cell with a hybrid (graphite + Li-metal) anode and compared it with currently used systems. The hybrid cathode was synthesized using various ratios of LiCoO2:LiV3O8, where the 80:20 wt% ratio yielded the best electrochemical performance. The graphite and Li-metal hybrid anode, the composition of which was calculated based on the amount of non-lithiated cathode material (LiV3O8), was used to synthesize a full cell. With the addition of LiV3O8, the discharge capacity of the LiCoO2 + LiV3O8 hybrid cathode increased from 142.03 to 182.88 mA h g−1 (a 28.76% improvement). The energy density of this cathode also increased significantly, from 545.96 to 629.24 W h kg−1 (a 15.21% improvement). The LiCoO2 + LiV3O8 hybrid cathode was characterized through X-ray diffraction analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Its electrochemical performance was analyzed using a battery-testing system and electrochemical impedance spectroscopy. We expect that optimized synthesis conditions will enable the development of a novel battery system with an increase in energy density and discharge capacity.

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