Preparation and Study of Spherical Nickel Hydroxide Coated by Cobalt Oxy-Hydroxide

2013 ◽  
Vol 668 ◽  
pp. 383-387 ◽  
Author(s):  
Xin Gang Hou ◽  
Wen Wu Liu ◽  
Cai Xia Li ◽  
You Fu Wang
Keyword(s):  
Nickel Hydroxide ◽  
Active Material ◽  
Specific Capacity ◽  
Chemical Precipitation ◽  
Constant Current ◽  
Precipitation Method ◽  
Electrochemical Characteristics ◽  
X Ray Diffraction ◽  
Constant Current Charge ◽  
Discharge Test

Nanometer nickel hydroxide particles coated by cobalt oxy-hydroxide are prepared through chemical precipitation method. The properties of coated Ni(OH)2 particles is characterized by using X-ray diffraction, scanning electron microscopy, constant current charge/discharge test and cyclic voltammetry. Studies are focused on the effects of different amounts of cobalt oxy-hydroxide on structure and electrochemical characteristics of nickel hydroxide. The results show that a structure of β-Ni(OH)2 is preserved and 2.5 wt % CoOOH can form a well distributed conductive network on the surface of nickel hydroxide particles, thereby leading to higher utilization of active material; Compared to other electrodes, the electrodes with 2.5 wt % coated CoOOH show higher specific capacity and better cycling durability, and the electrodes also has better reversibility of the Ni(OH)2/NiOOH redox couple, and higher oxygen evolution potential.

Synthesis and Electrochemical Properties of LiFe (PO4)(1-x/3)Fx/C as a Cathode Material

2013 ◽  
Vol 827 ◽  
pp. 16-19
Author(s):  
Shi Tao Song ◽  
Su Xia Wu ◽  
Zhi Wei Zhang ◽  
You Shun Peng
Keyword(s):  
Cathode Material ◽  
Effective Means ◽  
Specific Capacity ◽  
Lithium Ion ◽  
Constant Current ◽  
Electrochemical Performances ◽  
X Ray Diffraction ◽  
X Ray ◽  
Constant Current Charge ◽  
Discharge Experiment

on doping is an effective means to improve the performance of LiFePO4 material. In the present study, composites LiFe (PO4)(1-x/3)Fx/C (x=0.00,0.02,0.04,0.06,0.08,0.10) were synthesized by carbothermal reduction method. The as-synthesized samples were characterized by X-ray diffraction and scanning electron microscope, and their electrochemical performances were investigated by constant current charge-discharge experiment. The results indicated that the low concentration F dopant did not affect the structure of LiFePO4 but considerable improved its electrochemical performances. The LiFe (PO4)0.98F0.06/C materials showed better electrochemical performances than LiFePO4/C. At 0.2 C discharging rate, the LiFe (PO4)0.98F0.06/C materials was capable of delivering reversible specific capacity of 165.1 mAh/g, with fairly stable cycleability. The excellent performance indicates that this mix-doped composite was a very promising cathode material for lithium ion batteries.

scholarly journals Synthesis of Ni(OH)2, suitable for supercapacitor application, by the cold template homogeneous precipitation method

2021 ◽  
Vol 2 (6 (110)) ◽  
pp. 45-51
Author(s):  
Vadym Kovalenko ◽  
Valerii Kotok
Keyword(s):  
Energy Consumption ◽  
Nickel Hydroxide ◽  
Specific Capacity ◽  
Active Surface ◽  
High Energy ◽  
Spherical Particles ◽  
Precipitation Method ◽  
Electrochemical Characteristics ◽  
Homogeneous Precipitation ◽  
Supercapacitor Application

α-Ni(OH)2 obtained by template homogeneous precipitation exhibits high electrochemical activity in supercapacitors. The main disadvantage is the high energy consumption for maintaining a high temperature during synthesis. To reduce energy consumption, it is proposed to lower the synthesis temperature. In the study, α-Ni(OH)2 was obtained by the method of cold template homogeneous precipitation using Culminal C8465 (0.5 %) as a template for 6 months at t=20–35 °С. The electrochemical characteristics of the sample were studied by cyclic voltammetry and galvanostatic charge-discharge cycling of a pasted binder-free electrode made without introducing an external binder in the supercapacitor mode. It was determined that low-crystalline α-Ni(OH)2 was formed, consisting of agglomerates of spherical particles. Low specific characteristics of nickel hydroxide were revealed at the beginning of cycling due to blocking of the active surface. It was shown that the specific capacity of the sample increased with further cycling due to the breakdown of aggregates into smaller particles; specific capacities of 80 F/g and 38 mA⋅h/g were obtained. However, the lack of binding properties of the template residues was revealed, resulting in a decrease in specific characteristics. It was concluded that it was necessary to introduce an external binder. A previously undescribed effect of a significant increase in the specific capacity during drying of an alkali-impregnated electrode caused by the disintegration of particle agglomerates during alkali carbonization (the maximum capacity is 135 F/g and 69 mA⋅h/g) was revealed. It was concluded that using the revealed effect of any nickel hydroxide samples obtained by various methods of bulk template synthesis was promising

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

Synthesis and photocatalytic properties of magnetic separable and recyclable p-n heterojunction CoFe2O4/Bi12O17Cl2 photocatalyst

CrystEngComm ◽  
2021 ◽  
Author(s):  
Kexin Fang ◽  
Lei Shi ◽  
Lishuang Cui ◽  
Chunwei Shi ◽  
Weiwei Si
Keyword(s):  
Chemical Precipitation ◽  
Photocatalytic Properties ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Crystallinity

A series of CoFe2O4/Bi12O17Cl2 (CFO/Bi12O17Cl2) nanocomposites have been prepared by chemical precipitation method. The result of X-ray diffraction showed that CFO/Bi12O17Cl2 composites had high crystallinity. It was found that CoFe2O4...

Monodisperse Fe3O4/Fe Core/Shell Nanoparticles with Enhanced Magnetic Property

2011 ◽  
Vol 306-307 ◽  
pp. 410-415
Author(s):  
Li Sun ◽  
Fu Tian Liu ◽  
Qi Hui Jiang ◽  
Xiu Xiu Chen ◽  
Ping Yang
Keyword(s):  
Average Diameter ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Shell Nanoparticles ◽  
X Ray ◽  
Transmission Electron ◽  
Shell Particles ◽  
Core Shell Nanoparticles

Core/shell type nanoparticles with an average diameter of 20nm were synthesized by chemical precipitation method. Firstly, Monodisperse Fe3O4 nanoparticles were synthesized by solvethermal method. FeSO4ž7H2O and NaBH4 were respectively dissolved in distilled water, then moderated Fe3O4 particles and surfactant(PVP) were ultrasonic dispersed into the FeSO4ž7H2O solution. The resulting solution was stirred 2 h at room temperature. Fe could be deposited on the surface of monodispersed Fe3O4 nanoparticles to form core-shell particles. The particles were characterized by using various experimental techniques, such as transmission electron microscopy (TEM), X-ray diffraction (XRD), AGM and DTA. The results suggest that the saturation magnetization of the nanocomposites is 100 emu/g. The composition of the samples show monodisperse and the sides of the core/shell nanoparticles are 20-30nm. It is noted that the formation of Fe3O4/Fe nanocomposites magnetite nanoparticles possess superparamagnetic property.

Synthesis and Electrochemical Properties of a LiNi0.7Co0.3O1.9Cl0.1 Cathode Material for Lithium-Ion Battery

2007 ◽  
Vol 336-338 ◽  
pp. 463-465 ◽  
Author(s):  
Xin Lu Li ◽  
Fei Yu Kang ◽  
Yong Ping Zheng ◽  
Xiu Juan Shi ◽  
Wan Ci Shen
Keyword(s):  
Hexagonal Lattice ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Constant Current ◽  
Cyclic Voltammograms ◽  
X Ray Diffraction ◽  
X Ray ◽  
Constant Current Charge ◽  
Initial Cycle ◽  
Partial Oxygen

Partial oxygen in LiNi0.7Co0.3O2 was replaced by chlorine to form LiNi0.7Co0.3O1.9Cl0.1. Phase structure of LiNi0.7Co0.3O1.9Cl0.1 was identified as a pure hexagonal lattice of α-NaFeO2 type by X-ray diffraction. Discharge capacity of LiNi0.7Co0.3O1.9Cl0.1 was 202 mAh/g in initial cycle at 15 mA/g current density in 2.5- 4.3 V potential window. The constant current charge/discharge experiments and cyclic voltammograms showed that chlorine addition was effective to improve reversible capacity and cycle stability of LiNi0.7Co0.3O2.

Preparation and Electrochemical Performance of Mn3O4/GR Composites Electrode Material in Supercapacitors

2019 ◽  
Vol 807 ◽  
pp. 50-56
Author(s):  
Yun Long Zhou ◽  
Zhi Biao Hu ◽  
Li Mei Wu ◽  
Jiao Hao Wu
Keyword(s):  
Room Temperature ◽  
Raw Materials ◽  
Precipitation Method ◽  
Electrochemical Performances ◽  
Manganese Sulfate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
A Current ◽  
Discharge Test

Using hydrated manganese sulfate and general type graphene (GR) as raw materials, Mn3O4/GR composite has been successfully prepared by the liquid phase chemical co-precipitation method at room temperature. X-ray diffraction (XRD) was used to investigate the phase structure of Mn3O4powder and Mn3O4/GR composite; The electrochemical performances of the samples were elucidated by cyclic voltammetry and galvanostatic charge-discharge test in 0.5 mol/L Na2SO4electrolyte. The results show that the Mn3O4/GR composite possesses graphene phase and good reversibility; the composite also displays a specific capacitance of 318.8 F/g at a current density of 1 A/g.

scholarly journals Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 250 ◽  
Author(s):  
Francesco Baldassarre ◽  
Angela Altomare ◽  
Nicola Corriero ◽  
Ernesto Mesto ◽  
Maria Lacalamita ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Temperature ◽  
Inductively Coupled Plasma ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled

Europium-doped hydroxyapatite Ca10(PO4)6(OH)2 (3% mol) powders were synthesized by an optimized chemical precipitation method at 25 °C, followed by drying at 120 °C and calcination at 450 °C and 900 °C. The obtained nanosized crystallite samples were investigated by means of a combination of inductively coupled plasma (ICP) spectroscopy, powder X-ray diffraction (PXRD), Fourier Transform Infrared (FTIR), Raman and photoluminescence (PL) spectroscopies. The Rietveld refinement in the hexagonal P63/m space group showed europium ordered at the Ca2 site at high temperature (900 °C), and at the Ca1 site for lower temperatures (120 °C and 450 °C). FTIR and Raman spectra showed slight band shifts and minor modifications of the (PO4) bands with increasing annealing temperature. PL spectra and decay curves revealed significant luminescence emission for the phase obtained at 900 °C and highlighted the migration of Eu from the Ca1 to Ca2 site as a result of increasing calcinating temperature.

scholarly journals Effect of Annealing on the ZnS Nanocrystals Prepared by Chemical Precipitation Method

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Nadana Shanmugam ◽  
Shanmugam Cholan ◽  
Natesan Kannadasan ◽  
Kannadasan Sathishkumar ◽  
G. Viruthagiri
Keyword(s):  
Chemical Precipitation ◽  
Chemical Precipitation Method ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Visible Absorption ◽  
Atomic Force ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Uv Visible ◽  
Dta Curves

Nanocrystals of ZnS have been synthesized through simple chemical precipitation method using thiourea as sulphur source. The synthesized products were annealed at different temperatures in the range of 200–800∘C. The as-synthesized and annealed samples were characterized by X-ray diffraction (XRD), UV-Visible absorption (UV-Vis), and room temperature photoluminescence (PL) measurements. The morphological features of ZnS annealed at 200 and 500∘C were studied by atomic force microscope (AFM) and transmission electron microscope (TEM) techniques. The phase transformation of ZnS and formation of ZnO were confirmed by thermogravimetric (TG) and differential thermal analysis (DTA) curves.

Synthesis and Characterization of ZnS: Fe/ZnS Core-Shell Nanocrystals

2011 ◽  
Vol 148-149 ◽  
pp. 900-903
Author(s):  
Li Hua Li ◽  
Yong Jun Gu ◽  
Rui Shi Xie ◽  
Jian Guo Zhu
Keyword(s):  
Chemical Precipitation ◽  
Precipitation Method ◽  
Core Shell ◽  
X Ray Diffraction ◽  
Pl Spectra ◽  
Zinc Blende ◽  
Diffraction Peaks ◽  
Zns Nanocrystals ◽  
Zinc Blende Structure

ZnS:Fe and ZnS:Fe/ZnS core-shell nanocrystals were synthesized by chemical precipitation method. It was found that the ZnS: Fe based nanocrystals possess zinc blende structure. Compared to ZnS: Fe nanocrystals, the intensity of the X-ray diffraction peaks of ZnS: Fe/ZnS nanocrystals reduced and these peaks moved to lower angles. TEM images show that ZnS: Fe based nanocrystals are spheroidal and the average particles size is about 3~4 nm. PL spectra of ZnS: Fe nanocrystals revealed several mission bands, ~406nm, ~444nm, ~416nm, However, PL spectra of ZnS: Fe/ZnS nanocrystals showed several mission bands, ~420nm, ~432nm, ~449nm.

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