scholarly journals ZnO Nanocrystals as Anode Electrodes for Lithium-Ion Batteries

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Wenhui Zhang ◽  
Lijuan Du ◽  
Zongren Chen ◽  
Juan Hong ◽  
Lu Yue

ZnO nanocrystals were synthesized via a thermal decomposition method. X-ray diffraction, transmission electron microscopy, and photoluminescence were used to investigate the composition and nanostructure of the material. Compared with commercial ZnO nanoparticles, ZnO nanocrystals showed higher lithium storage capacity and better cycling characteristics and exhibited a reversible discharge capacity of 500 mAh g−1after 100 cycles at 200 mA g−1.

2011 ◽  
Vol 47 (1) ◽  
pp. 73-78 ◽  
Author(s):  
E. Darezereshki ◽  
F. Bakhtiari

In this study CuO nanoparticles were prepared via direct thermal decomposition method using basic copper sulphates as wet chemically synthesized precursor which was calcined in air at 750?C for 2h. Samples were characterized by thermogravimetric (TG-DSC), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), infrared spectrum (IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The XRD, EDS, and IR results indicated that the synthesized CuO particles were pure. The SEM and TEM results showed that the CuO nanoparticles were of approximate spherical shape, and 170?5 nm in size. Using this method, Cuo nanoparticles could be produced without using organic solvent, expensive raw materials, and complicated equipment.


2012 ◽  
Vol 535-537 ◽  
pp. 500-504 ◽  
Author(s):  
Hao Zheng ◽  
Xue Ya Jiang ◽  
Hui Min Wu ◽  
Mei Yu Dan ◽  
Chuan Qi Feng ◽  
...  

KMn8O16 nanorods were prepared by a rheological phase method using KMnO4 and Mn (CH3COO)2•4H2O as reactants. The samples were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results showed that the morphology of the samples was nanorods with a diameter of about 5~15 nm. The electrochemcial testing showed that the KMn8O16 nanorods annealed at 400 °C for 4 h exhibited good lithium storage properties, with a high reversible capability (143 mAh/g at current density of 50 mA/g) and stable lithium-ion insertion/de-insertion reversibility.


2013 ◽  
Vol 4 ◽  
pp. 699-704 ◽  
Author(s):  
Raju Prakash ◽  
Katharina Fanselau ◽  
Shuhua Ren ◽  
Tapan Kumar Mandal ◽  
Christian Kübel ◽  
...  

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.


NANO ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. 1650139 ◽  
Author(s):  
Lei Wang ◽  
Honglong Xing ◽  
Zhenfeng Liu ◽  
Ziyao Shen ◽  
Xiang Sun ◽  
...  

ZnO nanocrystals were introduced into Fe3O4/MWCNTs composites to improve the impedance matching and electromagnetic (EM) wave attenuation of the system. The as-synthesized ZnO/Fe3O4/MWCNTs composites were characterized by X-ray diffraction, vibrating sample magnetometer, field-emission scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy. SEM and TEM images showed that Fe3O4 microspheres 100–200[Formula: see text]nm in size connected MWCNTs. Analysis of EM parameters revealed that the impedance matching of the ZnO/Fe3O4/MWCNTs composites was considerably improved after ZnO nanocrystals were introduced. The ZnO/Fe3O4/MWCNTs composites exhibited a highly efficient microwave absorption (MA) capacity within the tested frequency range of 2–18[Formula: see text]GHz. The optimal reflection loss of EM waves was [Formula: see text][Formula: see text]dB at 6.08[Formula: see text]GHz with an absorber thickness of 3.5[Formula: see text]mm. The excellent MA properties of the composites could be attributed to the improved impedance matching, interfacial polarization, and combined effects of dielectric and magnetic losses.


2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Changyu Li ◽  
Shouxin Liu

Mesoporous nanosheets of single-crystallineβ-nickel hydroxide (β-Ni(OH)2) were successfully synthesized via a facile hydrothermal method using Ni(NO3)2 · 6H2O as precursor in a mixed solution of sodium hydroxide (NaOH) and sodium dodecylbenzenesulfonate (SDBS). Single-crystalline nickel oxide (NiO) mesoporous nanosheets can be obtained through a thermal decomposition method usingβ-Ni(OH)2mesoporous nanosheets as precursor. The influences of SDBS and hydrothermal treatment were carefully investigated; the results showed that they played important roles in the formation ofβ-Ni(OH)2mesoporous nanosheets. The as-obtainedβ-Ni(OH)2and NiO were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravity-differential thermal analysis (TG-DTA), and specific surface area, and pore size test.


2020 ◽  
Vol 20 (3) ◽  
pp. 1962-1967
Author(s):  
Zhen Liu ◽  
Wei Zhou ◽  
Guilin Zeng ◽  
Yuling Zhang ◽  
Zebin Wu ◽  
...  

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.


2020 ◽  
Vol 20 (5) ◽  
pp. 2911-2916
Author(s):  
Zhen Zhang ◽  
Xiao Chen ◽  
Guangxue Zhang ◽  
Chuanqi Feng

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.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012095
Author(s):  
Melbin Baby ◽  
K. Rajeev Kumar

Abstract In this work, we report synthesis of hybrid nanostructures of Transition Metal Dichalcogenides via thermal decomposition method. Ammonium tetrathiomolybdate was used as not only growth templates but also as starting precursor for synthesis of hybrid nanostructures. The conditions for the synthesizing method were optimized using electron microscopy and x-ray diffraction. In this hybrid nanostructure synthesis, it was found that MoO3 nanorods are interspersed on exfoliated MoS2 nanosheets. The structural and optical properties of the hybrid nanostructure were investigated using transmission electron microscopy (TEM), Scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy and Ultraviolet Visible spectrophotometry (UV-VIS). The hybrid nanostructure of MoO3 on MoS2 shows a band gap of 2.2 eV. It was also found that by tuning the preparation parameters viz temperature of heating and time of heating, the composition of the hybrid nanostructure can be varied.


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