A Comparison of Exfoliation Methods on Microstructure and Electrochemical Performance of Graphene Nanosheets for Supercapacitors

2012 ◽  
Vol 15 (2) ◽  
pp. 97-101 ◽  
Author(s):  
Xinlu Li ◽  
Hongfang Song ◽  
Hao Wang ◽  
Hongyi Li ◽  
Yuxin Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Expansion ◽  
Microwave Irradiation ◽  
Electrochemical Performance ◽  
Electrochemical Property ◽  
Graphene Nanosheets ◽  
Specific Capacity ◽  
N2 Adsorption ◽  
Transmission Electron ◽  
Galvanostatic Discharge

Graphene nanosheets (GNS) were exfoliated by thermal expansion and microwave irradiation, respectively. The influence of exfoliation methods on GNS’s surface structure and electrochemical property were analyzed. The porosity structure of GNS was measured by N2 adsorption. The N2 adsorption results proved that both the specific surface area and pore volume of the GNS exfoliated by thermal expansion are larger than those by microwave irradiation. And the surface morphology was observed by scanning electron microscopy and transmission electron microscopy. The electrochemical performance of the graphene nanosheets were comparatively tested by cyclic voltammetry and galvanostatic discharge-charge tests. The GNS via thermal expansion exhibited better electrochemical property with the specific capacity of 188 F/g at the current density of 0.1 A/g.

scholarly journals Effects of Nano Carbon Conductive Additives on the Electrochemical Performance of LiCoO2 Cathode for Lithium Ion Batteries

2015 ◽  
Vol 18 (3) ◽  
pp. 131-135 ◽  
Author(s):  
Xinlu Li ◽  
Xinlin Zhang ◽  
Tongtao Li ◽  
Qineng Zhong ◽  
Yanyan Yanyan Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Nanosheets ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Transmission Electron ◽  
Galvanostatic Discharge ◽  
Conductive Additives ◽  
Multi Walled Carbon Nanotubes ◽  
Adsorption Desorption ◽  
Walled Carbon Nanotubes

Carbon black(CB), multi-walled carbon nanotubes(CNTs) and graphene nanosheets(GNs) were employed as carbon conductive additives for LiCoO2(LCO). X-ray diffraction, transmission electron microscopy and scanning electron microscopy were used to characterize the crystal structure and morphology of samples. And the specific surface area and porosity structure of the three kinds of carbon conductive additives were measured by N2 adsorption-desorption. To investigate the effect on the electrochemical reaction activity, galvanostatic discharge-charge experiments showed that the composite of LCO-GNs exhibited the highest specific capacity of 167mAh/g at 0.1C and 123 mAh/g at 1 C rate. The flexible wrapping of GNs and bridging nearby LCO particles together were found to enhance electrical conductivity most effectively.

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.

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.

Asymmetric Cracking in Znse/ZnSxSel−x Superlattices Grown by Molecular Bean Epitaxy

1987 ◽  
Vol 102 ◽  
Author(s):  
Richard J. Dalby ◽  
John Petruzzello
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Thermal Expansion ◽  
Molecular Beam Epitaxy ◽  
Molecular Beam ◽  
Lattice Mismatch ◽  
Sulfur Concentration ◽  
Transmission Electron ◽  
Theoretical Predictions ◽  
Superlattice Layer

ABSTRACTOptical and transmission electron microscopy have been used to study cracks appearing in ZnSe/ZnSxSe1−x (x ∼ 0.38) superlattices grown by Molecular Beam Epitaxy. It Is shown that when a fracture occurs it is confined, in most cases, to the superlattice and propagates along <011> cleavage directions in these <001> oriented epilayers. Cracks were not observed in all superlattices and their onset is discussed in relation to sulfur concentration, overall superlattice height, individual superlattice layer thicknesses, and stress, tensile or compressive, due to lattice mismatch and thermal expansion differences between buffer layer and superlattice. It was found that by adjusting the controllable parameters, cracks in the superlattices could be eliminated. Orientation and density of these features have been related to asynnmetric cracking associated with the zincblende structure of these II-VI materials. Experimental results are shown to be in agreement with theoretical predictions of critical heights for the onset of cracking.

scholarly journals Ce-Doped PANI/Fe3O4 Nanocomposites: Electrode Materials for Supercapattery

2021 ◽  
Vol 3 ◽  
Author(s):  
Subash Pandey ◽  
Shova Neupane ◽  
Dipak Kumar Gupta ◽  
Anju Kumari Das ◽  
Nabin Karki ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrode Material ◽  
High Performance ◽  
Electrode Materials ◽  
Specific Capacity ◽  
Maximum Energy ◽  
Potential Range ◽  
X Ray Diffraction ◽  
Active Electrode ◽  
Transmission Electron

In this study, we report on a combined approach to preparing an active electrode material for supercapattery application by making nanocomposites of Polyaniline/Cerium (PANI/Ce) with different weight percentages of magnetite (Fe3O4). Fourier-transform infrared spectroscopy (FTIR) and x-ray diffraction (XRD) analyses supported the interaction of PANI with Ce and the formation of the successful nanocomposite with magnetite nanoparticles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses showed the uniform and porous morphology of the composites. Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) were used to test the supercapattery behavior of the nanocomposite electrodes in 1.0 M H2SO4. It was found that the supercapattery electrode of PANI/Ce+7 wt.% Fe3O4 exhibited a specific capacity of 171 mAhg−1 in the potential range of −0.2 to 1.0 V at the current density of 2.5 Ag−1. Moreover, PANI/Ce+7 wt.% Fe3O4 revealed a power density of 376.6 Wkg−1 along with a maximum energy density of 25.4 Whkg−1 at 2.5 Ag−1. Further, the cyclic stability of PANI/Ce+7 wt.% Fe3O4 was found to be 96.0% after 5,000 cycles. The obtained results suggested that the PANI/Ce+Fe3O4 nanocomposite could be a promising electrode material candidate for high-performance supercapattery applications.

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.

Enhanced electrochemical performance of lithium ion batteries using Sb2S3 nanorods wrapped in graphene nanosheets as anode materials

Nanoscale ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 3159-3165 ◽  
Author(s):  
Yucheng Dong ◽  
Shiliu Yang ◽  
Zhenyu Zhang ◽  
Jong-Min Lee ◽  
Juan Antonio Zapien
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Anode Materials ◽  
Graphene Nanosheets ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Lithium Insertion ◽  
Insertion Reactions ◽  
Theoretical Specific Capacity ◽  
Enhanced Electrochemical Performance

Antimony sulfide can be used as a promising anode material for lithium ion batteries due to its high theoretical specific capacity derived from sequential conversion and alloying lithium insertion reactions.

scholarly journals Novel Graphene/In2O3 Nanocubes Preparation and Selective Electrochemical Detection for L-Lysine of Camellia nitidissima Chi

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1999
Author(s):  
Jinsheng Cheng ◽  
Sheng Zhong ◽  
Weihong Wan ◽  
Xiaoyuan Chen ◽  
Ali Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Sensor ◽  
Chiral Recognition ◽  
Graphene Nanosheets ◽  
Reduction Reaction ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Camellia Nitidissima

In this work, novel graphene/In2O3 (GR/In2O3) nanocubes were prepared via one-pot solvothermal treatment, reduction reaction, and successive annealing technology at 600 °C step by step. Interestingly, In2O3 with featured cubic morphology was observed to grow on multi-layered graphene nanosheets, forming novel GR/In2O3 nanocubes. The resulting nanocomposites were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction spectroscopy (XRD), etc. Further investigations demonstrated that a selective electrochemical sensor based on the prepared GR/In2O3 nanocubes can be achieved. By using the prepared GR/In2O3-based electrochemical sensor, the enantioselective and chem-selective performance, as well as the optimal conditions for L-Lysine detection in Camellia nitidissima Chi, were evaluated. The experimental results revealed that the GR/In2O3 nanocube-based electrochemical sensor showed good chiral recognition features for L-lysine in Camellia nitidissima Chi with a linear range of 0.23–30 μmol·L−1, together with selectivity and anti-interference properties for other different amino acids in Camellia nitidissima Chi.

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.

Rapid Polymerisation with Microwave Irradiation for Transmission Electron Microscopy

2001 ◽  
Vol 39 (5) ◽  
pp. 313-317 ◽  
Author(s):  
Ilkin Cavusoglu ◽  
F. Zehra Minbay ◽  
Sehime G. Temel ◽  
Semiha Noyan
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Microwave Irradiation ◽  
Transmission Electron
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