Synthesis of ZnO/MWCNTs Nanostructure via Hydrothermal Method and its Electrochemical Capacitive Performance

2012 ◽  
Vol 512-515 ◽  
pp. 1763-1766
Author(s):  
Li Hua Lu ◽  
Liang Yu Gong
Keyword(s):  
Hydrothermal Method ◽  
Zno Nanorods ◽  
Hybrid Structure ◽  
Electrochemical Performances ◽  
Electrochemical Investigation ◽  
Multi Wall Carbon Nanotubes ◽  
Capacitive Properties ◽  
Zno Particles ◽  
Combined Structure ◽  
Charge Discharge

The composites of ZnO/multi-wall carbon nanotubes (ZnO/MWCNTs) were efficiently synthesized via a simple hydrothermal method, and their capacitive properties were evaluated by cyclic voltammetry (CV) and galvanostatical charge/discharge tests, respectively. The resulting ZnO/ MWCNTs composite displayed net-like combined structure, in which the flower-like ZnO particles assembled by ZnO nanorods were entangled by the MWCNTs, Electrochemical investigation exhibited that the highest specific capacitance of 310 F g-1was obtained when the content of MWCNTs reached to 20%, compared to the ZnO (55 F g-1) and MWCNTs electrode (17 F g-1), showing the synergistic effect of ZnO and MWCNTs. The excellent net-like hybrid structure and the good conductivity of MWCNTs were considered to be responsible for its preferable electrochemical performances.

Preparation of NiO Microspheres by Hydrothermal Method and its Electrochemical Capacitive Properties

2015 ◽  
Vol 814 ◽  
pp. 81-85 ◽  
Author(s):  
Qian Qian Li ◽  
Run Hua Fan ◽  
Ke Lan Yan ◽  
Kai Sun ◽  
Xu Ai Wang ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Electrochemical Impedance ◽  
Specific Capacity ◽  
Rate Capability ◽  
Average Diameter ◽  
Three Dimensions ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
High Specific Capacity ◽  
Capacitive Properties

The precursor Ni (OH)2 was synthesized by a simple hydrothermal method with hexamethylenetetramine ((CH2)6N4) as precipitant and template, and then NiO was gained after calcination. The phase and morphology of the synthesized product were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the electrochemical capacitive characterization was performed using cyclic voltammetry (CV), chronopotentiometry and electrochemical impedance spectroscopy (EIS) in a 6mol/L KOH aqueous solution electrolyte. The result shows that spherical NiO without impurity was synthesized, the average diameter of the spheres is 5 um and these spheres were constructed by the interactive arrangement of many nanoflakes in three dimensions. This kind of NiO shows the typical electrochemical characteristics of pseudo capacitance with high specific capacity and excellent rate capability. The specific capacity can reach 515F/g at the current density of 1A/g

Preparation and Electrochemical Performances of Calcium Zincate Synthesized by Microwave Method

2011 ◽  
Vol 236-238 ◽  
pp. 868-871 ◽  
Author(s):  
Meng Liang Tong ◽  
Xuan Yan Liu
Keyword(s):  
Cyclic Voltammetry ◽  
Active Material ◽  
Electrochemical Performances ◽  
Microwave Method ◽  
X Ray ◽  
Battery Charge ◽  
Secondary Battery ◽  
Initial Capacity ◽  
Charge Discharge ◽  
Discharge Test

Calcium zincate as an active material in Zn/Ni secondary battery has been successfully synthesized by microwave method. The chemical composition of Ca(OH)2·2Zn(OH)2·2H2O was confirmed by X-ray powder diffraction pattern and weight loss in thermogravimetric analysis.The results of cyclic voltammetry and experimental Zn/Ni battery charge–discharge test showed that the material of calcium zincate had excellent electrochemical performances: a high discharging platform of 1.685 V and a good cycleability, discharge capacity would be 70.0% of initial capacity after circulated 120 times.

Facile hydrothermal synthesis of Fe3O4 nanoparticle and effect of crystallinity on performances for supercapacitor

2019 ◽  
Vol 12 (02) ◽  
pp. 1950019 ◽  
Author(s):  
Yue Xu ◽  
Ying Zhang ◽  
Xiaolan Song ◽  
Hanjun Liu
Keyword(s):  
Hydrothermal Method ◽  
Reaction Times ◽  
Amorphous Structure ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
Oxide Electrode ◽  
Facile Hydrothermal Method ◽  
X Ray ◽  
Pseudocapacitive Behavior ◽  
Adsorption Desorption

Fe3O4 nanoparticles were synthesized by a facile hydrothermal method using triethanolamine. Effects of reaction times (2–8[Formula: see text]h) on crystallinity and electrochemical performances of Fe3O4 were investigated. Samples were analyzed by X-ray diffraction, infrared spectroscopy, N2 adsorption–desorption, scanning electron microscope, galvanostatic charge/discharge, and cyclic voltammetry. Results showed that the crystallinity of Fe3O4 was increased with hydrothermal time, and the sample prepared at 2[Formula: see text]h displayed amorphous structure with small grain size and large surface area of 165.0[Formula: see text]m2[Formula: see text]g[Formula: see text]. The sample exhibited typical pseudocapacitive behavior with capacitance of 383.2[Formula: see text]F[Formula: see text]g[Formula: see text] at 0.5 Ag[Formula: see text] in Na2SO3 electrolyte. After 2000 cycles, the capacitance retention of Fe3O4 at 2[Formula: see text]h was recorded as 83.6%, much higher than 26.3% for sample at 8[Formula: see text]h. It indicated that hydrothermal method was an effective approach to obtain amorphous Fe3O4, implying the potential application for preparing metal oxide electrode for supercapacitors.

scholarly journals Synthesis of Ga-Doped ZnO Nanorods by Hydrothermal Method and Their Application to Ultraviolet Photodetector

Inventions ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 3 ◽  
Author(s):  
Sheng-Joue Young ◽  
Chia-Lin Chiou ◽  
Yi-Hsing Liu ◽  
Liang-Wen Ji
Keyword(s):  
Hydrothermal Method ◽  
Zno Nanorods ◽  
Ultraviolet Photodetector ◽  
Doped Zno

Novel fabrication of various size ZnO nanorods using hydrothermal method

2010 ◽  
Vol 87 (5-8) ◽  
pp. 1534-1536 ◽  
Author(s):  
Seong-Jong Kim ◽  
Han-Hyoung Kim ◽  
Joo-Beom Kwon ◽  
Jong-Geun Lee ◽  
Beom-Hoan O ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Zno Nanorods

scholarly journals The Charge-Discharge Characteristics of Woody Carbon Modified with Fe3O4 Nano Phase Using the Hydrothermal Method

2010 ◽  
Vol 51 (1) ◽  
pp. 186-191 ◽  
Author(s):  
Chih-Hsien Wang ◽  
Fei-Yi Hung ◽  
Truan-Sheng Lui ◽  
Li-Hui Chen
Keyword(s):  
Hydrothermal Method ◽  
Discharge Characteristics ◽  
Charge Discharge

A High Rate, High Capacity and Long Life (LiFePO4+AC)/Li4Ti5O12 Hybrid Battery-Supercapacitor

2014 ◽  
Vol 936 ◽  
pp. 496-502
Author(s):  
Xue Bu Hu ◽  
Zi Ji Lin ◽  
Yong Long Zhang
Keyword(s):  
Leakage Current ◽  
Electrochemical Impedance ◽  
Discharge Rate ◽  
Performance Testing ◽  
High Energy ◽  
High Energy Density ◽  
Constant Current ◽  
Electrochemical Performances ◽  
Capacity Loss ◽  
Charge Discharge

A hybrid battery-supercapacitor (LiFePO4+AC)/Li4Ti5O12 using a Li4Ti5O12 anode and a LiFePO4/activated carbon (AC) composite cathode was built. The electrochemical performances of the hybrid battery-supercapacitor (LiFePO4+AC)/Li4Ti5O12 were characterized by constant current charge-discharge, rate charge-discharge, electrochemical impedance spectra, internal resistance, leakage current, self-discharge and cycle performance testing. The results show that (LiFePO4+AC)/Li4Ti5O12 hybrid battery-supercapacitors have rapid charge-discharge performance, high energy density, long cycle life, low resistance, low leakage current and self-discharge rate, which meet the requirements of practical power supply and can be applied in auxiliary power supplies for hybrid electric vehicles. At 4C rate, the capacity loss of (LiFePO4+AC)/Li4Ti5O12 hybrid battery-supercapacitors in constant current mode is no more than 7.71% after 2000 cycles, and the capacity loss in constant current-constant voltage mode is no more than 4.51% after 1500 cycles.

STUDY OF NANOSTRUCTURES OF ZINC OXIDE SYNTHESIZED BY LOW-TEMPERATURE HYDROTHERMAL METHOD

2018 ◽  
Vol 20 (4) ◽  
pp. 209-217
Author(s):  
S.S. Kurbanov ◽  
Sh.Z. Urolov ◽  
Z.Sh. Shaymardanov ◽  
R.R. Jalolov
Keyword(s):  
Low Temperature ◽  
Hydrothermal Method ◽  
Emission Band ◽  
Free Exciton ◽  
Zno Nanorods ◽  
Growth Direction ◽  
Orange Emission ◽  
Yellow Orange ◽  
Violet Band ◽  
Vertically Aligned

Room temperature photoluminescence (PL) properties of vertically aligned and spindle-shaped, randomly oriented ZnO nanorods synthesized by using a low temperature hydrothermal method are studied. In air, the vertically aligned ZnO nanorods oriented mainly parallel to the luminescencerecording axis exhibited only one, very strong UV emission peak at 382 nm. This band is assigned to emission of free excitons. A new violet PL band near 400 nm arises with increasing angle between the nanorod growth direction and the luminescence-recording axis. The violet band also appears under UV illumination in vacuum and vanishes after exposure to air. The randomly oriented ZnO nanorods along with free exciton related PL band reveal a broad yellow-orange emission band around 590 nm. The violet band is attributed to Zn vacancy related defects or their complexes, while the yellow-orange emission band is ascribed to oxygen interstitial related defects.

Layer-by-Layer Structure Design of G@SiOx@PPY Materials as Promising High-Performance Anodes for Lithium-Ion Batteries

NANO ◽  
2021 ◽  
pp. 2150120
Author(s):  
Jiaying Zhang ◽  
Ting Li ◽  
Chao Li ◽  
Jingjing Zhang ◽  
Chun Ju Lv ◽  
...  
Keyword(s):  
Current Density ◽  
Layer Structure ◽  
Synergetic Effect ◽  
Lithium Ion ◽  
Structure Design ◽  
Molar Ratio ◽  
Electrochemical Performances ◽  
Cyclic Stability ◽  
Discharge Cycle ◽  
Charge Discharge

The graphene/silicon oxide/polypyrrole (G/SiOx/PPY) material was prepared in this paper. The G/SiOx/PPY material has good electrochemical performances including high capacity and cyclic stability. It has 2068/2130[Formula: see text]mAh g[Formula: see text] of capacity after 100th charge/discharge cycle at 200[Formula: see text]mA[Formula: see text]g[Formula: see text] of current density and 575/569[Formula: see text]mAh[Formula: see text]g[Formula: see text] of capacity after 100th charge/discharge cycle at 2000[Formula: see text]mA g[Formula: see text] of current density when G/SiOx molar ratio is 1:5. Its capacity increases but its cyclic stability decreases with G/SiOx molar ratio decreasing from 1:1 to 1:3 and 1:5. The electrochemical performance improvement of the G/SiOx/PPY material is due to the synergetic effect of graphene and polypyrrole, which improve the conductivity of SiOx and prevent its dropping from the surface of the electrode caused by the stress due to the volume expansion and shrinkage in charge/discharge cycles.

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