scholarly journals Binder Free SnO2-CNT Composite as Anode Material for Li-Ion Battery

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Dionne Hernandez ◽  
Frank Mendoza ◽  
Emmanuel Febus ◽  
Brad R. Weiner ◽  
Gerardo Morell
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Tin Dioxide ◽  
Composite Films ◽  
Volume Ratio ◽  
Lithium Ion ◽  
Chemical Vapor ◽  
Li Ion Battery ◽  
X Ray ◽  
Li Ion

Tin dioxide-carbon nanotube (SnO2-CNT) composite films were synthesized on copper substrates by a one-step process using hot filament chemical vapor deposition (HFCVD) with methane gas (CH4) as the carbon source. The composite structural properties enhance the surface-to-volume ratio of SnO2demonstrating a desirable electrochemical performance for a lithium-ion battery anode. The SnO2and CNT interactions were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared-attenuated total reflectance (ATR-FTIR) spectroscopy. Comprehensive analysis of the structural, chemical, and electrochemical properties reveals that the material consists of self-assembled and highly dispersed SnO2nanoparticles in CNT matrix. The process employed to develop this SnO2-CNT composite film presents a cost effective and facile way to develop anode materials for Li-ion battery technology.

Synthesis of MoO3/V2O5/C Composite as Novel Anode for Li-Ion Battery Application

2020 ◽  
Vol 20 (5) ◽  
pp. 2911-2916
Author(s):  
Zhen Zhang ◽  
Xiao Chen ◽  
Guangxue Zhang ◽  
Chuanqi Feng
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Li Ion Battery ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Li Ion ◽  
Battery Application

The MoO3/V2O5/C, MoO3/C and V2O5/C are synthesized by electrospinning combined with heat treatment. These samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and thermogravimetric analysis (TG) techniques. The results show that sample MoO3/V2O5/C is a composite composed from MoO3, V2O5 and carbon. It takes on morphology of the nanofibers with the diameter of 200~500 nm. The TG analysis result showed that the carbon content in the composite is about 40.63%. Electrochemical properties for these samples are studied. When current density is 0.2 A g−1, the MoO3/V2O5/C could retain the specific capacity of 737.6 mAh g−1 after 200 cycles and its coulomb efficiency is 92.99%, which proves that MoO3/V2O5/C has better electrochemical performance than that of MoO3/C and V2O5/C. The EIS and linear Warburg coefficient analysis results show that the MoO3/V2O5/C has larger Li+ diffusion coefficient and superior conductivity than those of MoO3/C or V2O5/C. So MoO3/V2O5/C is a promising anode material for lithium ion battery application.

SURFACE DECORATION OF COMMERCIAL GRAPHITE MICROSPHERES WITH SMALL Si/C MICROSPHERES AS IMPROVED ANODE MATERIALS FOR Li-ION BATTERIES

2013 ◽  
Vol 01 (04) ◽  
pp. 1340017
Author(s):  
ZAILEI ZHANG ◽  
YANHONG WANG ◽  
MEIJU ZHANG ◽  
QIANGQIANG TAN ◽  
FABING SU
Keyword(s):  
Electron Microscopy ◽  
Composite Materials ◽  
Electrochemical Performance ◽  
Photoelectron Spectroscopy ◽  
Anode Materials ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Li Ion Batteries ◽  
X Ray ◽  
Li Ion

We report a facile chemical vapor deposition (CVD) method to grow silicon/carbon ( Si / C ) microspheres on commercial graphite microsphere (GMs) surface to prepare Si / C / GMs composite anode materials for Li -ion batteries. The CVD synthesis is conducted at 900°C using methyltrichlorosilane ( CH 3 SiCl 3) as both the Si and C precursor, which is a cheap byproduct in organosilane industry. The samples are characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy and X-ray photoelectron spectroscopy. It is found that the obtained Si / C / GMs composites are composed of Si nanocrystals, amorphous carbon and GMs. The CVD time significantly influences the morphology and electrochemical performance of the Si / C / GMs composite materials. The Si / C / GMs composite materials prepared at CVD condition of 900°C for 4 h possess improved electrochemical properties, showing a discharge capacity of 821.4 mAh g−1 at a rate of 50 mA g−1, and a good cycling performance (i.e., a reversible capacity of 565.2 mAh g−1 is retained after 50 cycles). The enhanced electrochemical performance is attributed to the formation of Si / C microsphere network among GMs, which increases the electronic conductivity and is able to buffer the large volume changes of Si during lithium ion insertion/extraction.

scholarly journals Polyarylene Ether Nitrile and Barium Titanate Nanocomposite Plasticized by Carboxylated Zinc Phthalocyanine Buffer

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 418 ◽  
Author(s):  
Shuning Liu ◽  
Chenchen Liu ◽  
Changyu Liu ◽  
Ling Tu ◽  
Yong You ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Barium Titanate ◽  
Photoelectron Spectroscopy ◽  
Energy Dispersive Spectrometer ◽  
Composite Films ◽  
Zinc Phthalocyanine ◽  
Hydroxyl Groups ◽  
X Ray ◽  
Polyarylene Ether Nitrile ◽  
High Dielectric

Barium titanate (BT) and polyarylene ether nitrile (PEN) nanocomposites with enhanced dielectric properties were obtained by using carboxylatedzinc phthalocyanine (ZnPc-COOH) buffer as the plasticizer. Carboxylated zinc phthalocyanine, prepared through hydrolyzing ZnPc in NaOH solution, reacted with the hydroxyl groups on the peripheral of hydrogen peroxide treated BT (BT-OH) yielding core-shell structured BT@ZnPc. Thermogravimetric analysis (TGA), transmission electron microscopy (TEM), TEM energy dispersive spectrometer mapping, scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) demonstrated successful preparation of BT@ZnPc. The fabricated BT@ZnPc was incorporated into the PEN matrix through the solution casting method. Rheological measurements demonstrated that the ZnPc-COOH buffer can improve the compatibility between BT and PEN effectively. With the existence of the ZnPc-COOH buffer, the prepared BT@ZnPc/PEN nanocomposites exhibit a high dielectric constant of 5.94 and low dielectric loss (0.016 at 1000 Hz). BT@ZnPc/PEN dielectric composite films can be easily prepared, presenting great application prospects in the field of organic film capacitors.

scholarly journals In Situ and In Operando Techniques to Study Li-Ion and Solid-State Batteries: Micro to Atomic Level

Inorganics ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 85
Author(s):  
Maryam Golozar ◽  
Raynald Gauvin ◽  
Karim Zaghib
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Atomic Level ◽  
X Ray ◽  
In Situ Techniques ◽  
Transmission Electron ◽  
Wide Range ◽  
Li Ion

This work summarizes the most commonly used in situ techniques for the study of Li-ion batteries from the micro to the atomic level. In situ analysis has attracted a great deal of interest owing to its ability to provide a wide range of information about the cycling behavior of batteries from the beginning until the end of cycling. The in situ techniques that are covered are: X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Scanning Transmission Electron Microscopy (STEM). An optimized setup is required to be able to use any of these in situ techniques in battery applications. Depending on the type of data required, the available setup, and the type of battery, more than one of these techniques might be needed. This study organizes these techniques from the micro to the atomic level, and shows the types of data that can be obtained using these techniques, their advantages and their challenges, and possible strategies for overcoming these challenges.

Laser-Based Fabrication of Carbon Nanotube–Metal Composites on a Polymer Substrate: Experimental Study and Characterizations

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Zheng Kang ◽  
Jitendra Kumar Tripathi ◽  
Muxuan Wang ◽  
Ahmed Hassanein ◽  
Benxin Wu
Keyword(s):  
Electron Microscopy ◽  
Carbon Nanotube ◽  
Photoelectron Spectroscopy ◽  
Composite Films ◽  
Polymer Substrate ◽  
Metal Composite ◽  
X Ray ◽  
Polyimide Substrate ◽  
Transmission Electron ◽  
Potential Applications

Abstract Flexible electronic devices have several advantages and multiple current or potential applications. However, the reliability and durability of their metal components (which often exist) may suffer from large and repeated strains during many applications. Carbon nanotube (CNT)-metal composite films that were laser-sintered on flexible substrates were shown to be very promising in addressing the reliability and durability issues. However, to the authors’ best knowledge, CNT–metal interfaces in a laser-sintered CNT–metal composite film on a polymer substrate and the composite–polymer interface have not been sufficiently characterized and understood. In this paper, CNT–silver composite films were produced on polyimide substrates by laser sintering, and the fabricated samples were characterized through scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy. Under the conditions studied, it has been found that: (1) for the CNT–silver interfaces in the composite, a significant amount of Ag–C chemical bonds is unlikely to exist, and (2) for the composite–polyimide interface, mechanical interlocking is expected to play an important role in the interfacial adhesion, while a significant diffusion of silver into the polyimide substrate is not observed. Besides, chemical reactions have likely occurred around the interface, causing the formation of Ag2O due to the reaction between silver from the composite and oxygen (in a certain form) from the polyimide substrate.

Thickness of carbon coatings on silicon materials determined by hard X-ray photoelectron spectroscopy at multiple photon energies

2019 ◽  
Vol 26 (6) ◽  
pp. 1936-1939 ◽  
Author(s):  
Noritake Isomura ◽  
Naoko Takahashi ◽  
Satoru Kosaka ◽  
Hiroyuki Kawaura
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Secondary Electron ◽  
Lithium Ion ◽  
Cross Sectional ◽  
Carbon Coatings ◽  
X Ray ◽  
Negative Electrodes ◽  
Silicon Materials ◽  
Microscopy Images

Hard X-ray photoelectron spectroscopy at multiple photon energies is used to investigate the surface structure of carbon coatings on silicon materials destined for use as negative electrodes in lithium-ion batteries. The photoelectron intensity from the carbon coatings decreases with an increase in the kinetic energy of the photoelectron. By fitting the photoelectron intensity versus energy to numerically derived curves, the thickness and coverage of the carbon coatings can be obtained. The results are in agreement with the values suggested by the cross-sectional secondary-electron microscopy images of the carbon coatings, although the thickness should be corrected by accounting for the rectangular parallelepiped structure of the silicon material.

scholarly journals Eco-friendly synthesis of VO 2 with stripped pentavalent vanadium solution extracted from vanadium-bearing shale by hydrothermal process in high conversion rate

2019 ◽  
Vol 6 (2) ◽  
pp. 181116 ◽  
Author(s):  
Qian Kang ◽  
Yimin Zhang ◽  
Shenxu Bao ◽  
Guobin Zhang
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Conversion Rate ◽  
Hydrothermal Process ◽  
Lithium Ion ◽  
Raw Material ◽  
High Concentration ◽  
X Ray ◽  
Pentavalent Vanadium ◽  
High Conversion Rate

VO 2 (B) has shown excellent cathode performance in lithium batteries and become a hot research topic in recent years. A stripped vanadium solution extracted from vanadium-bearing shale containing a high concentration of vanadium and certain amounts of impurities was used as a vanadium source to synthesize VO 2 (B) by hydrothermal process. The VO 2 conversion rate can reach as high as 99.47% in a reaction time of 8 h, and this is the highest result reported. The crystalline structure and morphology of the synthesized products were characterized by X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). Furthermore, the electrochemical properties of VO 2 (B) in lithium-ion batteries were investigated. The results indicated that the VO 2 (B) has the initial specific discharge capacity of 192.0 mAh g −1 . Stripped vanadium solution is a raw material for producing V 2 O 5 and NH 4 VO 3 , which are indispensable vanadium sources in VO 2 synthesis. Therefore, synthesis of VO 2 via hydrothermal reduction by oxalic acid using stripped vanadium solution extracted from vanadium-bearing shale as a direct vanadium source is an eco-friendly, innovative and efficient method, and will have a great impact on VO 2 synthesis.

Effect of Sintering on Structural Modification and Phase Transition of Al-Substituted LLZO Electrolytes for Solid State Battery Applications

2021 ◽  
Vol 18 (3) ◽  
Author(s):  
K. Ganesh Kumar ◽  
P. Balaji Bhargav ◽  
C. Balaji ◽  
Ahmed Nafis ◽  
K. Aravinth ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid State ◽  
Solid Electrolyte ◽  
Photoelectron Spectroscopy ◽  
Lithium Ion ◽  
Impedance Analysis ◽  
Chemical Compositions ◽  
X Ray ◽  
Reitveld Refinement ◽  
Solid State Battery

Abstract Owing to high lithium ion conductivity and good stability with lithium metal, Li7La3Zr2O12 (LLZO—a solid electrolyte) has emerged as a viable candidate for solid-state battery applications. In the current study, Al-substituted LLZO (Al-LLZO) powder is synthesized using a typical solid-state reaction. The pellets are made with the synthesized powder and are subjected to annealing for different durations and its effect on the structural properties of the Al-LLZO is investigated in detail. Reitveld refinement of the powder X-ray diffraction pattern reveals that the sintered Al-LLZO belong to the cubic system with the Ia-3d space group at room temperature. Morphology and microstructural properties of sintered powder are analyzed using field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM)/selected area electron diffraction (SAED), respectively. The FESEM image of LLZO pellets shows well-structured cubic grains spread evenly over on the surface after sintering. The chemical compositions of the sample are identified using energy dispersive X-ray analysis (EDAX). The surface chemistry of the prepared samples is examined by X-ray photoelectron spectroscopy (XPS), which states that the observed photoelectron signals from O 1s at about 531 eV and Li1s at 54.52 eV correspond to the Li-O bond in Al-LLZO. Raman spectra have been analyzed and the observed Raman peaks appearing at 299 cm−1, 393 cm−1, 492 cm−1, and 514 cm−1 were assigned to Eg, F2g, A1g, and F2g, respectively. Phase transformation from C-LLZO to the pyrochore LZO phase is noticed when the sample is sintered for 12 h at 1100 °C. The impedance analysis is carried out to measure the conductivity of the Al-LLZO pellet and is found to be 0.3 × 10−5 S cm−1, which is suitable for solid electrolyte applications in lithium ion batteries.

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