scholarly journals EG-Assisted Synthesis and Electrochemical Performance of Ultrathin Carbon-Coated LiMnPO4Nanoplates as Cathodes in Lithium Ion Batteries

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Liwei Su ◽  
Yali Sha ◽  
Jingkang Jiang ◽  
Lianbang Wang ◽  
Yuanhao Wang
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Lithium Ion ◽  
X Ray Diffraction ◽  
Electrochemical Behaviors ◽  
X Ray ◽  
Pyrolysis Method ◽  
Transmission Electron ◽  
Carbon Coated

Ultrathin carbon-coated LiMnPO4(ULMP/C) nanoplates were prepared through an ethylene glycol- (EG-) assisted pyrolysis method. Different from most of LiMnPO4/C works, the obtained ULMP/C possessed relatively small particle size (less than 50 nm in thickness) and preferable carbon coating (~1 nm in thickness, 2 wt.%). As a reference, LiMnPO4/C (LMP/C) composites were also fabricated via the traditional hydrothermal method. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TG), galvanostatic charge-discharge, and cyclic voltammetry (CV) were performed to characterize the crystalline phase, morphology, structure, carbon content, and electrochemical behaviors of samples. The electrochemical performance of bare and carbon-coated LiMnPO4was evaluated as cathodes in lithium ion batteries. As a result, the obtained ULMP/C nanoplates demonstrated much higher reversible capacities (110.9 mAh g−1after 50 cycles at 0.1 C) and rate performances than pure LMP and LMP/C composites. This facile and efficient EG-assisted pyrolysis method can enlighten us on exploiting advanced routes to modify active materials with ultrathin and homogeneous carbon layers.

scholarly journals Spherical Li4Ti5O12/NiO Composite With Enhanced Capacity and Rate Performance as Anode Material for Lithium-Ion Batteries

2020 ◽  
Vol 8 ◽  
Author(s):  
Jiequn Liu ◽  
Shengkui Zhong ◽  
Qingrong Chen ◽  
Luchao Meng ◽  
Qianyi Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lithium Ion Batteries ◽  
Anode Material ◽  
Discharge Capacity ◽  
Lithium Ion ◽  
Drying Method ◽  
X Ray Diffraction ◽  
Composite Powders ◽  
X Ray ◽  
Transmission Electron

Compositing with metal oxides is proved to be an efficient strategy to improve electrochemical performance of anode material Li4Ti5O12 for lithium-ion batteries. Herein, spherical Li4Ti5O12/NiO composite powders have been successfully prepared via a spray drying method. X-ray diffraction and high-resolution transmission electron microscopy results demonstrate that crystal structure of the powders is spinel. Scanning electron microscopy results show that NiO uniformly distributes throughout Li4Ti5O12 matrix. It is found that compositing with NiO increases both discharge platform capacity and rate stability of Li4Ti5O12. The as-prepared Li4Ti5O12/NiO (5%) exhibits a high initial discharge capacity of 381.3 mAh g−1 at 0.1 C, and a discharge capacity of 194.7 mAh g−1 at an ultrahigh rate of 20 C.

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.

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.

scholarly journals A facile synthesis of a carbon-encapsulated Fe3O4 nanocomposite and its performance as anode in lithium-ion batteries

2013 ◽  
Vol 4 ◽  
pp. 699-704 ◽  
Author(s):  
Raju Prakash ◽  
Katharina Fanselau ◽  
Shuhua Ren ◽  
Tapan Kumar Mandal ◽  
Christian Kübel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Lithium Ion ◽  
Iron Pentacarbonyl ◽  
X Ray Diffraction ◽  
Facile Synthesis ◽  
X Ray ◽  
Transmission Electron ◽  
Lithium Ion Cell ◽  
Carbon Framework ◽  
One Step

A carbon-encapsulated Fe3O4 nanocomposite was prepared by a simple one-step pyrolysis of iron pentacarbonyl without using any templates, solvents or surfactants. The structure and morphology of the nanocomposite was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis and Raman spectroscopy. Fe3O4 nanoparticles are dispersed intimately in a carbon framework. The nanocomposite exhibits well constructed core–shell and nanotube structures, with Fe3O4 cores and graphitic shells/tubes. The as-synthesized material could be used directly as anode in a lithium-ion cell and demonstrated a stable capacity, and good cyclic and rate performances.

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.

scholarly journals Centrifugally Spun α-Fe2O3/TiO2/Carbon Composite Fibers as Anode Materials for Lithium-Ion Batteries

2019 ◽  
Vol 9 (19) ◽  
pp. 4032 ◽  
Author(s):  
Luis Zuniga ◽  
Gabriel Gonzalez ◽  
Roberto Orrostieta Chavez ◽  
Jason C. Myers ◽  
Timothy P. Lodge ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Composite Fiber ◽  
Carbon Composite ◽  
Composite Fibers ◽  
X Ray ◽  
Binder Free

We report results on the electrochemical performance of flexible and binder-free α-Fe2O3/TiO2/carbon composite fiber anodes for lithium-ion batteries (LIBs). The composite fibers were produced via centrifugal spinning and subsequent thermal processing. The fibers were prepared from a precursor solution containing PVP/iron (III) acetylacetonate/titanium (IV) butoxide/ethanol/acetic acid followed by oxidation at 200 °C in air and then carbonization at 550 °C under flowing argon. The morphology and structure of the composite fibers were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). These ternary composite fiber anodes showed an improved electrochemical performance compared to the pristine TiO2/C and α-Fe2O3/C composite fiber electrodes. The α-Fe2O3/TiO2/C composite fibers also showed a superior cycling performance with a specific capacity of 340 mAh g−1 after 100 cycles at a current density of 100 mA g−1, compared to 61 mAh g−1 and 121 mAh g−1 for TiO2/C and α-Fe2O3/C composite electrodes, respectively. The improved electrochemical performance and the simple processing of these metal oxide/carbon composite fibers make them promising candidates for the next generation and cost-effective flexible binder-free anodes for LIBs.

Electrochemical Performance Cr Doped Spinel LiMn2O4 Cathode for Lithium Ion Batteries

2014 ◽  
Vol 636 ◽  
pp. 49-53
Author(s):  
Si Qi Wen ◽  
Liang Chao Gao ◽  
Jia Li Wang ◽  
Lei Zhang ◽  
Zhi Cheng Yang ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Electrochemical Impedance ◽  
Sol Gel ◽  
Lithium Ion ◽  
Cycling Performance ◽  
Cycle Performance ◽  
X Ray Diffraction ◽  
X Ray ◽  
Discharge Test

To improve the cycle performance of spinel LiMn2O4as the cathode of 4 V class lithium ion batteries, spinel were successfully prepared using the sol-gel method. The dependence of the physicochemical properties of the spinel LiCrxMn2-xO4(x=0,0.05,0.1,0.2,0.3,0.4) powders powder has been extensively investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), charge-discharge test and electrochemical impedance spectroscopy (EIS). The results show that as Mn is replaced by Cr, the initial capacity decreases, but the cycling performance improves due to stabilization of spinel structure. Of all, the LiCr0.2Mn1.8O4has best electrochemical performance, 107.6 mAhg-1discharge capacity, 96.1% of the retention after 50 cycles.

Facile Synthesis of Tremella-Like Li3V2(PO4)3/C Composite Cathode Materials Based on Oroxylum for Use in Lithium-Ion Batteries

2020 ◽  
Vol 20 (3) ◽  
pp. 1962-1967
Author(s):  
Zhen Liu ◽  
Wei Zhou ◽  
Guilin Zeng ◽  
Yuling Zhang ◽  
Zebin Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cathode Materials ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Composite Cathode ◽  
Potential Range ◽  
X Ray Diffraction ◽  
Immersion Method ◽  
X Ray ◽  
Transmission Electron

Oroxylum as a traditional Chinese medicine, was used as a green and novel bio-template to synthesize tremella-like Li3V2(PO4)3/C composite (LVPC) cathode materials by adopting a facile immersion method. The microstructures were analyzed by X-ray diffraction analysis, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties were investigated by galvanostatic charge–discharge experiments. The LVPC revealed specific capacity of 95 mAh·g-1 at 1 C rate within potential range of 3.0–4.3 V. After 100 cycles at 0.2 C, the retention of discharge capacity was 96%. The modified electrochemical performance is mainly resulted from the distinct tremella-like structure.

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