scholarly journals Synthesis and Characterization of Lixfepo4/C-Ppy Composite Cathode Material with Excess of Li+ Doping

2019 ◽  
Vol 9 (2) ◽  
pp. 5254-5257
Keyword(s):  
Composite Cathode ◽  
Chemical Precipitation ◽  
Polymerization Process ◽  
Step Method ◽  
Xrd Pattern ◽  
Li Doping ◽  
Unit Cell Size ◽  
Transmission Electron ◽  
Heat Treated

In-situ Polypyrrole (PPy) coating was performed on the surface of LixFePO4 /C (x=0.95 to 1.20) particles using iron (III) tosylate as oxidizer. The composite material LixFePO4 /C (x=0.95 to 1.20) was synthesized by two step method. FePO4 /polyaniline particles were first synthesized by chemical precipitation and were further heat treated with lithium acetate and sucrose under reduced atmosphere. XRD pattern confirms that Li+ addition to LiFePO4 has increased interplaner spacing and of the unit cell size. Impurity phase appears with x=1.15 and 1.20 which further disappears after polymer coating. After polymerization process the XRD pattern shows Li0.05FePO4 and LiFePO4 phases and both the phases have same electrochemical behavior. Morphology of the LixFePO4 /C and LixFePO4 /C-PPy was studied by using FE-SEM and it was found that particles are spherical with size range below 200nm. Transmission Electron Microscope (TEM) also confirms that LixFePO4 /C isolated particles were well encapsulated within the polymer matrix

In Situ Fabrication of Nanoscale Graphene Oxide/Polyaniline Composite and its Electrochemical Properties

2010 ◽  
Vol 148-149 ◽  
pp. 1547-1550 ◽  
Author(s):  
Hua Lan Wang ◽  
Qing Li Hao ◽  
Xi Feng Xia ◽  
Zhi Jia Wang ◽  
Jiao Tian ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
In Situ Polymerization ◽  
Ammonium Persulfate ◽  
Polymerization Process ◽  
Electrochemical Test ◽  
X Ray ◽  
Transmission Electron

A graphene oxide/polyaniline composite was synthesized by an in situ polymerization process. This product was simply prepared in an ethylene glycol medium, using ammonium persulfate as oxidant in ice bath. The composite was characterized by field emission scanning electron microscopy, transmission electron microscopy, X-Ray photoelectron spectroscopy, Raman spectroscopy and electrochemical test. The composite material showed a good electrochemical performance.

Direct Preparation of Ce0.8Sm0.2O1.9 Powders Oxidized With H2O2 for Low Temperature SOFCs Application

2005 ◽  
Author(s):  
Jianbing Huang ◽  
Zongqiang Mao ◽  
Bin Zhu ◽  
Lizhai Yang ◽  
Ranran Peng ◽  
...  
Keyword(s):  
Single Phase ◽  
Fluorite Structure ◽  
X Ray Diffraction ◽  
Composite Electrolyte ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Direct Preparation ◽  
Novel Method ◽  
Power Densities

A novel method was developed to prepare fine doped ceria (DCO) powders directly. Ceria doped with 20 mol. % of samarium (Ce0.8Sm0.2O1.9, SDC) was prepared by in-situ oxidization of hydroxide precipitates with H2O2 in the solutions. The resultant powder desiccated at 85°C overnight was characterized by X-ray diffraction (XRD), thermogravimetry /differential thermal analysis (TG/DTA), and transmission electron microscopy (TEM). The XRD pattern showed that the as-dried SDC powder is single phase with a cubic fluorite structure like that of pure CeO2. An anode-supported SOFC was also fabricated based on SDC and 20wt. % (62mol. %Li2CO3–38 mol. %K2CO3) composite electrolyte, LiNiO2 as cathode and NiO as anode, by cold pressing. Using hydrogen as the fuel and air as the oxidant, the I-V and I-P characteristics exhibit excellent performances and the maximum power densities are about 696, 469, 377 and 240 mWcm−2 at 650, 600, 550 and 500°C, respectively.

An in Situ Transmission Electron Microscopy Study During NH3 Ambient Annealing of Cu-Cr Thin Films

1993 ◽  
Vol 317 ◽  
Author(s):  
Z. Atzmon ◽  
R. Sharma ◽  
J.W. Mayer ◽  
S.Q. Hong
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Transmission Electron Microscopy Study ◽  
Nitridation Process ◽  
Transmission Electron ◽  
Heat Treated

ABSTRACTNitridation of Cu-Cr alloy films under an NH3 ambient was studied using in situ transmission electron Microscopy. Cu-Cr thin films (40–100 nm) were deposited on a single crystal NaCl substrate by electron beam coevaporation, and were heat treated up to 750°C at 2.5–3.0 Torr NH3. The films were also vacuum (10-6 Torr) annealed under the same conditions for comparison. Initial observation of Cu and Cr crystallization occurred at 470°C for both environmental conditions. The nitridation process of Cr to form CrN was observed initially at 580°C and was followed by evolution of faceted Cu grain growth in the CrN Matrix.

In Situ TEM Heating Study of the γ Lamellae Formation inside the α2 Matrix of a Ti-45Al-7.5Nb Alloy

2010 ◽  
Vol 146-147 ◽  
pp. 1365-1368 ◽  
Author(s):  
Li Mei Cha ◽  
Helmut Clemens ◽  
Gerhard Dehm ◽  
Zao Li Zhang
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ex Situ ◽  
In Situ Tem ◽  
Transmission Electron ◽  
Initial Stage ◽  
Heat Treated ◽  
The Matrix ◽  
In Situ Heating

In-situ heating transmission electron microscopy (TEM) was employed to investigate the initial stage of lamellae formation in a high Nb containing γ-TiAl based alloy. A Ti-45Al-7.5Nb alloy (at %), which was heat treated and quenched in a non-equilibrium state such that the matrix consists of ordered a2 grains, was annealed inside a TEM up to 750 °C. The in-situ TEM study reveals that g laths precipitate in the a2 matrix at ~ 750 °C possessing the classical Blackburn orientation relationship, i.e. (0001)a2 // (111)g and [11-20]a2 // <110]g. The microstructure of the in-situ TEM experiment is compared to results from ex-situ heating and subsequent TEM studies.

Micromagnetic Processes in Steels

1991 ◽  
Vol 232 ◽  
Author(s):  
A. D. Beale ◽  
M. G. Hetherington ◽  
J. P. Jakubovics ◽  
B. A. Lewis ◽  
C. B. Scruby
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Domain Structure ◽  
Magnetic Domain ◽  
Magnetic Domain Structure ◽  
Magnetoacoustic Emission ◽  
Transmission Electron ◽  
Heat Treated

ABSTRACTMagnetoacoustic emission (MAE) and Barkhausen emission (BE) measurements have been carried out on steel specimens heat treated to produce various microstructures ranging from martensitic/bainitic to ferritic/pearlitic. The magnetic domain structure of the specimens has been studied using transmission electron microscopy, and micromagnetic processes have been observed using an in-situ magnetizing device. The results are used in the interpretation of the MAE and BE measurements.

Twist fibrous structure of CS–SnO2–PANI ternary hybrid composite for electrochemical capacitance performance

RSC Advances ◽  
2016 ◽  
Vol 6 (46) ◽  
pp. 40567-40576 ◽  
Author(s):  
M. Karpuraranjith ◽  
S. Thambidurai
Keyword(s):  
Hybrid Composite ◽  
Oxidative Polymerization ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Step Method ◽  
Aniline Monomer ◽  
Ammonium Persulphate ◽  
Capacitance Performance ◽  
Simple Chemical

In this study, a twisted fibrous CS–SnO2–PANI ternary hybrid composite structure was synthesized via a two step method; the CS–SnO2 hybrid composite was prepared by a simple chemical precipitation method and the resulting CS–SnO2 suspension was coated with PANI by in situ chemical oxidative polymerization of aniline monomer in acidic medium using ammonium persulphate as the oxidant.

A Jeolco 200A Cartridge with Specimen Heating, Tilting, and Power Provisions

1975 ◽  
Vol 33 ◽  
pp. 152-153
Author(s):  
R. M. Anderson ◽  
J. K. Howard ◽  
P. Fullam
Keyword(s):  
Integrated Circuits ◽  
Thin Metal Film ◽  
Ex Situ ◽  
In Situ Observation ◽  
Electron Microscopic ◽  
Transmission Electron Microscopic Study ◽  
Transmission Electron ◽  
Heat Treated ◽  
Gradient Effects

The transmission electron microscopic study of thin metal film interconnections on electronic integrated circuits requires a sophisticated in-situ capability. Electromigration, particularly, cannot be investigated solely by viewing static heat-treated or electrically stressed specimens ex-situ. The key to the early electromigration studies by Blech, and others, was the in-situ observation of material movement in anelectrical-powering-stage equipped TEM. Blech's approach was insensitive to structure effects because of an absence of heating capability; he therefore relied on joule heating and temperature gradient effects.

scholarly journals In-situ Polymerization of exfoliated structure PA6/organo-clay nanocomposites

2020 ◽  
Vol 59 (1) ◽  
pp. 434-440
Author(s):  
Yiming Sun ◽  
Jie Mei ◽  
Huan Hu ◽  
Jiru Ying ◽  
Weiyi Zhou ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
In Situ Polymerization ◽  
Polyamide 6 ◽  
Interlayer Distance ◽  
Polymerization Process ◽  
Ammonium Bromide ◽  
Transmission Electron ◽  
Cetyl Trimethyl Ammonium ◽  
20 Nm

AbstractMontmorillonite (MMT) was modified with cetyl trimethyl ammonium bromide (CTAB) to obtain organomontmorillonite (OMMT) by stirring and pulsed ultrasonic mixing. Polyamide 6 (PA6)/OMMT nanocomposites were then prepared via in-situ polymerization.The resulting OMMT and PA6/OMMT nanocomposites were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results suggested that the OMMT interlayer distance was greatly increased to 3.13 nm due to CTAB being inter-calated into the MMT galleries. The OMMT interlayer distance was further enlarged to 10-20 nm during the polymerization process. The OMMT layers were exfoliated into nanoscale layers and uniformly dispersed in the molten ∈-caprolactam and PA6 matrix, and exfoliated structure nanocomposites were formed.

scholarly journals Fe-Co-B Soft Magnetic Ribbons: Crystallization Process, Microstructure and Coercivity

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1639
Author(s):  
Anna Wojcik ◽  
Wojciech Maziarz ◽  
Maciej Kowalczyk ◽  
Robert Chulist ◽  
Maciej Szlezynger ◽  
...  
Keyword(s):  
Heating Rate ◽  
Volume Fraction ◽  
Soft Magnetic ◽  
Microstructural Investigation ◽  
Transmission Electron ◽  
Heat Treated ◽  
Melt Spun ◽  
Mean Size ◽  
Residual Amorphous Matrix

In this work, a detailed microstructural investigation of as-melt-spun and heat-treated Fe67Co20B13 ribbons was performed. The as-melt-spun ribbon was predominantly amorphous at room temperature. Subsequent heating demonstrated an amorphous to crystalline α-(Fe,Co) phase transition at 403 °C. In situ transmission electron microscopy observations, carried out at the temperature range of 25–500 °C and with the heating rate of 200 °C/min, showed that the first crystallized nuclei appeared at a temperature close to 370 °C. With a further increase of temperature, the volume of α-(Fe,Co) crystallites considerably increased. Moreover, the results showed that a heating rate of 200 °C/min provides for a fine and homogenous microstructure with the α-(Fe,Co) crystallites size three times smaller than when the ribbon is heated at 20 °C/min. The next step of this research concerned the influence of both the annealing time and temperature on the microstructure and coercivity of the ribbons. It was shown that annealing at 485 °C for a shorter time (2 s) led to materials with homogenous distribution of α-(Fe,Co) crystallites with a mean size of 30 nm dispersed in the residual amorphous matrix. This was reflected in the coercivity (20.5 A/m), which significantly depended on the volume fraction of crystallites, their size, and distribution.

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