scholarly journals Effect of Carbon Additives on the Electrochemical Performance of Li4Ti5O12/C Anodes

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3941
Author(s):  
Irina Stenina ◽  
Ruslan Shaydullin ◽  
Tatiana Kulova ◽  
Anna Kuz’mina ◽  
Nataliya Tabachkova ◽  
...  
Keyword(s):  
Carbon Black ◽  
Electrochemical Performance ◽  
Rate Capability ◽  
Carbon Matrix ◽  
X Ray Diffraction ◽  
Discharge Rates ◽  
Transmission Electron ◽  
Carbon Additives ◽  
Promising Application ◽  
Carbon Replicas

The Li4Ti5O12/C composites were prepared by a hydrothermal method with in situ carbon addition. The influence of the morphology and content of various carbon materials (conductive carbon black, mesoporous carbon G_157M, and carbon replicas) on the electrochemical performance of the Li4Ti5O12/C composites was investigated. The obtained composites were characterized using X-ray diffraction, scanning electron microsopy, high-resolution transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy, and N2 sorption-desorption isotherms. Morphology of the Li4Ti5O12/C composites depends on the carbon matrix used, while both morphology and the amount of carbon material have a great impact on the rate capability and cycling stability of the obtained composites. At low current densities, the Li4Ti5O12/C composite with 5 wt.% G_157M exhibits the highest discharge capacity, while at high charge-discharge rates, the Li4Ti5O12/carbon black composites show the best electrochemical performance. Thus, at ~0.1C, 5C, and 18C rates, the discharge capacities of the obtained Li4Ti5O12/C composites are 175, 120, and 70 mAh/g for G_157M, 165, 126, and 78 mAh/g for carbon replicas, and 173, 128, and 93 mAh/g for carbon black. After 100 cycles, their capacity retention is no less than 95%, suggesting their promising application perspective.

scholarly journals V2O3/C composite fabricated by carboxylic acid-assisted sol–gel synthesis as anode material for lithium-ion batteries

2021 ◽  
Author(s):  
G. S. Zakharova ◽  
E. Thauer ◽  
A. N. Enyashin ◽  
L. F. Deeg ◽  
Q. Zhu ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Sol Gel ◽  
Carbon Sources ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Electron Microscopies ◽  
Transmission Electron ◽  
Battery Electrode ◽  
Sol Gel Synthesis

AbstractThe potential battery electrode material V2O3/C has been prepared using a sol–gel thermolysis technique, employing vanadyl hydroxide as precursor and different organic acids as both chelating agents and carbon sources. Composition and morphology of resultant materials were characterized by X-ray diffraction, Raman spectroscopy, scanning and transmission electron microscopies, physical sorption, and elemental analysis. Stability and electronic properties of model composites with chemically and physically integrated carbon were studied by means of quantum-chemical calculations. All fabricated composites are hierarchically structured and consist of carbon-covered microparticles assembled of polyhedral V2O3 nanograins with intrusions of amorphous carbon at the grain boundaries. Such V2O3/C phase separation is thermodynamically favored while formation of vanadium (oxy)carbides or heavily doped V2O3 is highly unlikely. When used as anode for lithium-ion batteries, the nanocomposite V2O3/C fabricated with citric acid exhibits superior electrochemical performance with an excellent cycle stability and a specific charge capacity of 335 mAh g−1 in cycle 95 at 100 mA g−1. We also find that the used carbon source has only minor effects on the materials’ electrochemical performance.

scholarly journals Characterization and Electrochemical Behavior of Graphene-Based Anode for Li-Ion Batteries

2011 ◽  
Vol 5 (1) ◽  
pp. 236-241 ◽  
Author(s):  
Wei-Ren Liu ◽  
Shin-Liang Kuo ◽  
Chia-Yi Lin ◽  
Yi-Chen Chiu ◽  
Ching-Yi Su ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Nanosheets ◽  
Rate Capability ◽  
Reversible Capacity ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Li Ion ◽  
Synthetic Graphite ◽  
Lower Impedance ◽  
Enhanced Electrochemical Performance

In this study, we investigate the characteristics and electrochemical properties of graphene nanosheets derived from chemical-thermal exfoliation processes of SFG44 synthetic graphite (SFG44-GNS). The characterizations and electrochemical measurements were carried out by means of X-ray diffraction, scanning electron microscopy, transmission electron microscopy, cyclic voltammetry, BET, Raman, rate capability as well as cycling tests and AC impedance. The as-synthesized SFG44-GNS with larger d-spacing of 0.3407 nm exhibits reversible capacity of 626 mAh/g and good rate capability of ~ 300 mAh/g at 2C rate, which are superior to those of graphite anode. The enhanced electrochemical performance of GNS anode was resulted from larger d-spacing, lower impedance in the interface and enhanced pore volume. The results indicate that graphene-based material is a good candidate for HEV/EV application.

Hydrothermal Synthesis and Electrochemical Performance of WO3 Nanoparticles

2013 ◽  
Vol 750-752 ◽  
pp. 217-220
Author(s):  
Li Jin Feng ◽  
Rong Ma ◽  
Xiu Hua Li ◽  
Xu Chun Song
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cyclic Voltammetry ◽  
Hydrothermal Synthesis ◽  
Electrochemical Performance ◽  
Electrochemical Activity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Hydrogen Intercalation ◽  
Transmission Electron

In the present paper, the WO3 nanoparticles were fabricated via a hydrothermal treatment. The products are characterized in detail by multiform techniques: transmission electron microscopy, X-ray diffraction. The results show that products are WO3 nanoparticles with diameter of about 100-150 nm. Electrochemistry properties of the prepared WO3 nanoparticles was characterized by cyclic voltammetry. Cyclic voltammetry results indicate that WO3 nanoparticles exhibits a remarkable electrochemical activity for hydrogen intercalation. The reason for electrochemical activity of WO3 nanoparticles is attributed to the formation of HxWO3 by hydrogen intercalation/de-intercalation into/out of the tungsten oxide.

Preparation and Properties of TiO2(B)/Graphene Nanocomposites as Anode Materials Fo Lithium-Ion Batteries

2014 ◽  
Vol 875-877 ◽  
pp. 183-186 ◽  
Author(s):  
Yi Ping Tang ◽  
Shi Ming Wang ◽  
Jia Feng Ding ◽  
Guang Ya Hou ◽  
Guo Qu Zheng
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Anode Materials ◽  
Graphene Nanosheets ◽  
Coulombic Efficiency ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Graphene Nanocomposites ◽  
Transmission Electron ◽  
Uniform Diameter

In this work, TiO2(B) nanotubes with uniform diameter were prepared by the simple route of hydrothermal synthesis, and graphene nanosheets were added to form TiO2(B)/graphene nanocomposites, the two kinds of materials were comparatively studied as anode materials. The morphology and crystal structure were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The electrochemical performance was evaluated by galvanostatic chargedischarge tests. The results show that the nanocomposite electrode material has good electrochemical performance due to the contributions of graphene. At the current density of 50mA/g, the capacity of TiO2(B)/graphene is 135.8 mAh/g, and the coulombic efficiency is 61.8%, after 10 charge-discharge cycles it still retains 113.2mAh/g . However, TiO2(B) anode reduces rapidly to 65.6 mAh/g.

Engineering Iron-Based Nanoparticles Spatially Dispersed on Mesoporous Carbon and Its Catalytic Activity for the Direct Oxidization of Benzene to Phenol

NANO ◽  
2018 ◽  
Vol 13 (08) ◽  
pp. 1850094
Author(s):  
Qiang Sun ◽  
Long Liu ◽  
Yi-Ding Li ◽  
Zeng-Rong Wang ◽  
Xue Zhang
Keyword(s):  
Mesoporous Carbon ◽  
Molecular Diffusion ◽  
Carbon Matrix ◽  
Mesoporous Structure ◽  
X Ray Diffraction ◽  
Efficient Catalyst ◽  
X Ray ◽  
Transmission Electron ◽  
Benzene Hydroxylation ◽  
Iron Based

We report engineered iron-based nanoparticles supported on cagelike mesoporous carbon that leaves its most mesopores empty to retain an open pore network and are expected to be efficient catalyst with fast molecular diffusion/transportation. The nano-scale iron-based particle inlayed in mesoporous carbon catalyst was obtained via the introduction of N atoms as an anchor. Results of X-ray diffraction, N2 sorption and transmission electron microscopy showed that the cagelike mesoporous structure of the carbon matrix was retained during catalyst preparation and iron-based nanoparticles were spatially dispersed on the mesoporous carbon. Importantly, it was found that the obtained iron-based nanoparticles inlayed into mesoporous carbon with a low Fe loading of 1.26[Formula: see text]wt.% was an appropriate catalyst for the benzene hydroxylation to phenol using H2O2 as the oxidant. At a low temperature of 30∘C, 19.4% conversion to benzene and 14.6% phenol yield were obtained; in addition, the catalyst could be recycled at least four times.

Microstructure of Pyrolytic Carbon Matrix in Carbon/Carbon Composites after Graphitization

2007 ◽  
Vol 336-338 ◽  
pp. 1270-1273 ◽  
Author(s):  
Wan Chang Sun ◽  
He Jun Li ◽  
Shou Yang Zhang ◽  
Yong Huang
Keyword(s):  
Polarized Light ◽  
Carbon Matrix ◽  
Pyrolytic Carbon ◽  
Interplanar Distance ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Before And After ◽  
The Matrix ◽  
Microstructure Parameters

The morphologies and textures of the pyrolytic carbon matrix in 2D-C/C composites after graphitization were investigated by means of polarized light microscope (PLM) and high resolution transmission electron microscope (HRTEM). The microstructure parameters of the pyrolytic carbon matrix before and after graphitization were characterized with X-ray diffraction (XRD) technology. It was found that the interplanar distance of (002) planes (d002) of pyrolytic carbon matrix decreases, and the microcrystalline stack height (LC) increases after graphitization. Graphitization treatment resulted in a coarsening of the surface texture and in the formation of circumferential cracks within the matrix. The lattice fringes of the pyrolytic carbon matrix are continuous and longer in each domain and the (002) peak spot is smaller and more intense after graphitization.

Preparation and Chromatic Properties of Encapsulated Carbon Black Pigment via Layer-by-Layer Self-Assembly Method

2015 ◽  
Vol 1104 ◽  
pp. 15-20 ◽  
Author(s):  
Xiao Jun Zhang ◽  
Ting Chen ◽  
Wei Hui Jiang ◽  
Jian Min Liu ◽  
Tong Qing Zhou
Keyword(s):  
Carbon Black ◽  
Self Assembly ◽  
Black Pigment ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Assembly Method ◽  
Transmission Electron ◽  
Color System ◽  
Chromatic Properties ◽  
Cie Color System

Encapsulated carbon black pigment was prepared by layer-by-layer self-assembly method. The RX8002 carbon black particles were well coated by a SiO2 layer, which makes it has good connection with ZrSiO4 layer. Meanwhile, dense ZrSiO4 layer was coated on the C@SiO2 particles surface to prevent the corrosive effects of glaze. The structure and morphology of samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The chromatic value of the pigments was measured by the CIE color system. The results show that the carbon black particles can be well coated by SiO2 and ZrSiO4 layer. When the TEOS/H2O ratio is 0.002 and the ZrSiO4/C ratio is 0.71, the chromatic value of the encapsulated carbon black pigment is 42.55, and the pigment has a good stability in glaze.

The preparation and electrochemical performance of Mo6S8 as cathode materials for magnesium ion batteries

2019 ◽  
Vol 34 (01n03) ◽  
pp. 2040012
Author(s):  
Zekun Wang ◽  
Jianfeng Huang ◽  
Jiayin Li
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Specific Capacity ◽  
Reversible Capacity ◽  
X Ray Diffraction ◽  
Chevrel Phase ◽  
Transmission Electron ◽  
Magnesium Batteries ◽  
Magnesium Ion Batteries ◽  
Rechargeable Magnesium Batteries

In this work, we reported a Chevrel phase [Formula: see text], which was synthesized by a molten salt approach, and its electrochemical performance as a cathode material for rechargeable magnesium batteries. The phase composition and micromorphology of the product were measured and analyzed by X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Chevrel phase sulfide delivered an excellent specific capacity of 91 mAh g[Formula: see text] at a current density of 0.2 C after 70 cycles. Its excellent reversible capacity, rate performance and cycle stability demonstrate the feasibility of the Chevrel phase [Formula: see text] materials for future rechargeable magnesium batteries.

Pressure Dependent Magnetization of Arc Discharge Fe–C Soot

2016 ◽  
Vol 843 ◽  
pp. 96-100 ◽  
Author(s):  
S.A. Novopashin ◽  
N.A. Demin ◽  
A.V. Zaikovskii
Keyword(s):  
Magnetic Susceptibility ◽  
Arc Discharge ◽  
Iron Carbide ◽  
Carbon Matrix ◽  
Size Distribution Function ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Carbon Soot ◽  
Iron Iron ◽  
Means Of Transmission

This Composite Fe-C anode sputtering in a low-pressure arc discharge has been used to produce Fe-containing nanoparticles on a carbon matrix. Magnetic susceptibility as a function of background pressure has been measured. The data obtained showed the complex, no-monotonous dependency. The material synthesized at optimal pressure (maximal value of magnetic susceptibility) was investigated by means of transmission electron microscopy, X-ray diffraction and magnetometry. Size distribution function of iron containing nanoparticles has been measured. Chemical composition includes iron, iron carbide and carbon soot. Saturation magnetization have been measured and it was shown that the synthesized material is superparamagnetic. The physical processes resulting in the complex behavior of magnetic susceptibility are discussed.

Synthesis and Characterization of Carbon-Encapsulated Nickel Nanoparticles from De-Oiled Asphalt

2013 ◽  
Vol 652-654 ◽  
pp. 202-205
Author(s):  
Jun Yu ◽  
Bing She Xu
Keyword(s):  
Nickel Nanoparticles ◽  
Carbon Matrix ◽  
Core Shell ◽  
Ni Nanoparticles ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
Nickel Powders ◽  
Transmission Electron ◽  
Core Shell Nanoparticles

Carbon-encapsulated Ni nanoparticles with the size of 5 to 30 nm were synthesized from de-oiled asphalt (DOA) by heat-treatment at 1800 °C with nickel powder. The nanoparticles exhibited well-constructed core-shell structures, with Ni cores and graphitic shells. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) examinations confirmed that the carbon-encapsulated Ni nanoparticles were uniformly dispersed in carbon matrix and the Ni nanoparticles were surrounded by several carbon layers with well ordered arrangement. The formation of the core-shell nanoparticles was selectively controlled by adjusting the ratio of de-oiled asphalt to nickel powders. The possible growth model for the carbon-encapsulated Ni nanoparticles was discussed briefly. This result presents a simple and controllable way to synthesize carbon-encapsulated nickel nanoparticles.

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