Preparation and Electrochemical Properties of CeO2/rGO Composite Material

2020 ◽  
Vol 842 ◽  
pp. 76-82
Author(s):  
Jin Hui Xu ◽  
Lin Wu ◽  
Ying Liu ◽  
Jia Ming Liu ◽  
Sha Sha Shu ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Specific Capacitance ◽  
Redox Reactions ◽  
Active Sites ◽  
Composite Electrode ◽  
Electrochemical Stability ◽  
Cycle Performance ◽  
Constant Current ◽  
Constant Current Charge ◽  
Structure And Microstructure

The CeO2/rGO composites were prepared by hydrothermal method. The microscopic phase structure and microstructure of the samples were characterized by SEM, XRD and FTIR. The cyclic voltammetry (CV) and constant current charge and discharge tests were used to study the electrochemical stability and cycle ability of the CeO2/rGO composite electrode. The results show that the incorporation of graphene effectively increases the reversibility of CeO2 as an electrode material. The special structure of graphene provides a continuous network and more active sites for redox reactions. In the 6mol/L KOH electrolyte, the specific capacitance of CeO2/rGO composite reached 114F·g-1 when the current density was 0.5A/g. After 1000 cycles, the specific capacitance only decreased by 12.66%, which proves that this material has good cycle performance.

Preparation and Electrochemical Characterization of Mn/Pb Composite Oxides for Supercapacitors

2007 ◽  
Vol 336-338 ◽  
pp. 470-473
Author(s):  
Zhian Zhang ◽  
Yan Qing Lai ◽  
Jie Li ◽  
Ye Xiang Liu
Keyword(s):  
Specific Capacitance ◽  
Electrochemical Characterizations ◽  
Amorphous Structure ◽  
Electrode System ◽  
Constant Current ◽  
Manganese Acetate ◽  
Composite Oxides ◽  
Constant Current Charge ◽  
Nano Size

Mn/Pb composite oxides were prepared by solid-state reaction by KMnO4 with manganese acetate and lead acetate at low temperature. The products were characterized by XRD and TEM. The results show that the composite oxides are nano-size and amorphous structure. Electrochemical characterizations were performed by cyclic voltammetry (CV) and constant current charge-discharge in a three-electrode system. The potential windows of Mn/Pb composite oxides electrode are increased. With increasing the ratio of Pb, the specific capacitance goes through a maximum at 20% mol Pb. The specific capacitance of pure MnO2 is 158 F/g and is improved to 180 F/g for the Mn0.8Pb0.2Ox composite oxide by constant current discharge.

Surface Oxidation Modification and Performance of Activated Carbon Electrode Material

2011 ◽  
Vol 347-353 ◽  
pp. 3456-3458
Author(s):  
Ren Qing Wang ◽  
Mei Gen Deng
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Surface Oxidation ◽  
Constant Current ◽  
Carbon Electrode ◽  
Constant Current Charge ◽  
And Performance ◽  
Double Layer Capacitors

Superscript text Commercial activated carbon was modified by surface treatment using nitric acid, The modified carbons were characterized by X-ray photoelectron spectroscopy (XPS).The resultant carbon electrode-based electric double-layer capacitors (EDLCs)were assembled with 1 mol/L （NH4）2SO4 as the electrolyte. The influence of introduced functional groups, such as hydroxyl and carbonyl, on the performance of EDLCs was studied by Constant current charge-discharge. These functional groups significantly improved the wettability of AC. As a result, the specific capacitance of the carbon modified with 40wt.%HNO3 achieved a specific capacitance of 223.45 F/g at a current density of 5mA/cm2, which is 100.9% higher than that of original AC.

A Facile Synthesis of NiFe2O4 with High Specific Capacitance as Supercapacitor Electrode Material

2018 ◽  
Vol 281 ◽  
pp. 854-858
Author(s):  
Xi Cheng Gao ◽  
Jian Qiang Bi ◽  
Wei Li Wang ◽  
Guo Xun Sun ◽  
Xu Xia Hao ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Capacitance ◽  
Electrochemical Property ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Constant Current Charge ◽  
Supercapacitor Electrode Materials

NiFe2O4 powders were synthesized by a facile hydrothermal method at 180°C followed by a thermal treatment at 300°C. The phase composition and morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed that the NiFe2O4 powders were well-crystallized, and they possessed a particle size in the range of 50-100 nm. The electrochemical property was characterized via cyclic voltammetry (CV) and constant current charge-discharge method. Encouragingly, the NiFe2O4 powders had an excellent electrochemical property, whose specific capacitance reached 266.84 F/g at the electric current density of 1 A/g due to the small particle size. Compared with other Fe-based metal compound oxides, NiFe2O4 has a better electrochemical performance, which can be widely used in the supercapacitor electrode materials.

Graphene-NiO Composite Electrode for Supercapacitors

2011 ◽  
Vol 345 ◽  
pp. 75-78 ◽  
Author(s):  
Wei Zhou ◽  
Man Lin Tan ◽  
Xiao Song Zhou
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Electrochemical Properties ◽  
Specific Capacitance ◽  
Composite Electrode ◽  
Electrochemical Impedance ◽  
Graphene Sheets ◽  
Supercapacitor Electrode ◽  
Scan Rate

In this paper, a facilesolution method was employed to synthesize the graphene-NiO composite. SEM and XRD results indicated the graphene sheets were covered by the NiO nanoplates. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to measure the electrochemical properties of the composite. The specific capacitance reached 1292F/g at a scan rate of 5mV/s. The results show that this composite is a promising material for supercapacitor electrode.

MESOPOROUS CARBON ELECTRODE: SYNTHESIS, CHARACTERIZATION AND ELECTROCHEMICAL PROPERTIES

2010 ◽  
Vol 03 (03) ◽  
pp. 161-164 ◽  
Author(s):  
XI LONG ◽  
CHUNXIA ZHAO ◽  
WEN CHEN
Keyword(s):  
Cyclic Voltammetry ◽  
Electrochemical Properties ◽  
Mesoporous Carbon ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Constant Current ◽  
Surface Areas ◽  
Constant Current Charge ◽  
Adsorption Desorption ◽  
Charge Discharge

The present paper studies a kind of mesoporous carbon (MC) with high electrochemical performance, which was prepared by vapor infiltration method. The microstructure and electrochemical properties of the mesoporous carbon were investigated by transmission electron microscopy (TEM), nitrogen adsorption–desorption isotherms, cyclic voltammetry (CV), constant current charge–discharge cycling (CD), and the long-term stability test. The results indicated that the mesoporous carbon has an ordered mesoporous structure, with pore size of about 3.87 nm and surface areas of 1087 m2 ⋅ g-1. The cyclic voltammetry curve reveals typical electrical double-layer capacitor property. After 200 cycles, the CV curves can almost be overlapped, which indicates excellent cycling stability. From the charge/discharge cycling, the specific capacitance of MC is 117 F ⋅ cm-1 in 1.0 M KNO3 electrolyte media at a scan rate of 1.0 mV ⋅ s-1, which decays with increasing current density. The charge–discharge efficiency also decays with it.

Effect of Rare Earth Doping on Electrochemical Properties of Fe2O3 Nanoparticle for Supercapacitor

2018 ◽  
Vol 281 ◽  
pp. 743-747
Author(s):  
Wei Kang Yan ◽  
Jian Qiang Bi ◽  
Wei Li Wang
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Constant Current ◽  
Rare Earth Doping ◽  
X Ray Diffraction ◽  
Super Capacitor ◽  
X Ray ◽  
Constant Current Charge ◽  
Discharge Method ◽  
Structure And Microstructure

Fe2O3 nanoparticle was prepared by a hydrothermal method, and the influence of rare earth elements (Y3+, Nd3+ and La3+) on the electrochemical performance was studied. The crystal structure and microstructure of the synthesized lithium zinc ferrite were characterized by X-ray diffraction (XRD),scanning electron microscopy (SEM). The results show that the powder is well crystallized and the particles are mostly irregular.The electrochemical property was characterized via cyclic voltammetry (CV) and constant current charge-discharge method. The capacitance of the Fe2O3 nanoparticle is 258.3 F/g, 342.7 F/g after doping Y3+ ,337.1 F/g after doping Nd3+and 331.2 F/g after doping La3 +. The results show that the rare earth elements (Y3+, Nd3+ and La3+) after the specific capacitance has increased, more suitable for super capacitor materials.

Hybrid Supercapacitors Based on Polyaniline and Carbon Aerogels Composite Electrode Materials

2011 ◽  
Vol 391-392 ◽  
pp. 18-22
Author(s):  
Zheng Jin ◽  
Dong Yu Zhao ◽  
Bo Hong Li ◽  
Xiao Min Ren ◽  
Shan Tao Yan ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Specific Capacitance ◽  
Composite Electrode ◽  
Electrode Materials ◽  
Electrochemical Impedance ◽  
Carbon Aerogels ◽  
Composite Electrodes ◽  
Long Cycle Life ◽  
Hybrid Supercapacitors

The purpose of this paper is to develop feasible composite electrodes with a long cycle life and large specific capacitance and to investigate optimal ratio between aniline and carbon aerogels (CA) materials. The characterization of the composite electrode materials was studied by using scanning electron microscopy (SEM), electrochemical impedance spectroscopy, cyclic voltammetry (CV) and the constant charge-discharge. The specific capacitance of the composite electrode materials, measured using cyclic voltammetry at scan rate of 1mV•s-1, was found to be 1139.66F•g-1. For a simple supercapcitor, the highest specific capacitance (127.53 F•g-1 at 30mA) is obtained at ratio between aniline and CA is 1:4.

scholarly journals High Proton Conducting Polymer Blend Electrolytes Based on Chitosan:Dextran with Constant Specific Capacitance and Energy Density

Biomolecules ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 267 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
M. H. Hamsan ◽  
Wrya O. Karim ◽  
M. F. Z. Kadir ◽  
M. A. Brza ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Energy Density ◽  
Specific Capacitance ◽  
Polymer Blend ◽  
Linear Sweep Voltammetry ◽  
Transference Number ◽  
Ammonium Fluoride ◽  
Constant Current ◽  
Discharge Process ◽  
Charge Discharge

Polymer blend electrolytes based on chitosan: dextran (CS:Dext) incorporated with various amounts of ammonium fluoride (NH4F) with constant specific capacitance (12.4 F/g) and energy density over 100 cycles were prepared using a solution cast technique. The blend electrolyte samples exhibit broader amorphous humps in X-ray diffraction (XRD) spectra compared to pure CS:Dext film. The Fourier transform infrared (FTIR) study indicates the complex formation of the added ammonium salt with the polymer blend functional groups through the shifting and decrease in the intensity of FTIR bands. The impedance plots were used to determine the conductivity of the samples. The field emission scanning electron microscopy (FESEM) images support the conductivity behavior of the samples. The impedance plots were applied in the determination of the conductivity of the samples in which the relatively highest conductivity was gained to be 1 × 10−3 S/cm. The transference number measurement (TNM) of the conducting electrolyte was 0.88, which portrays the dominancy of ion in the conduction process. Linear sweep voltammetry (LSV) verified the chemical stability and showed it to be 1.7 V and an effective electrical double layer capacitor (EDLC) that is applicable in electrochemical devices. The performance of the EDLC cell was examined using both cyclic voltammetry and constant current charge–discharge techniques at ambient temperature. The semi-rectangular shape of the cyclic voltammetry (CV) plot and no redox peak was observed. The charge-discharge process of the fabricated EDLC is durable over 100 cycles with an equivalent circuit resistance and power density of 194.5 Ω and 428 W/kg, respectively. Two main outcomes, the specific capacitance and energy densities of 12.4 Farad/g and 1.4 Wh/kg, respectively, are almost constant over 100 cycles.

Effect of Ultrasonic Disperse on the Properties of Carbon Nanotubes Supercapacitors

2010 ◽  
Vol 148-149 ◽  
pp. 1417-1420 ◽  
Author(s):  
Xin Sheng Yuan ◽  
Hai Yan Zhang ◽  
Yi Ming Chen
Keyword(s):  
Carbon Nanotubes ◽  
Specific Capacitance ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Constant Current ◽  
Ultrasonic Dispersion ◽  
Supercapacitor Electrode ◽  
Constant Current Charge ◽  
Lani5 Alloy ◽  
Charge Discharge

Carbon nanotubes (CNTs) of different diameter were synthesized by chemical vapor deposition using LaNi5 alloy of micrometer magnitude as catalyst. High-power ultrasonic grinder was employed to disperse CNTs for various time. CNTs with different dispersion levels were obtained and their impacts on the performance of CNTs supercapacitor electrode were researched as well. Constant current charge-discharge, Cycle Votammetry was employed to study the supercapacitors properties of carbon nanotubes. And the results showed that the specific capacitance of CNTs electrode without ultrasonic was 95.88F/g. However CNTs electrode has preferable electrochemistry properties with 16 hours ultrasonic dispersion, CNTs diameter about 30-50nm and well dispersibility: the specific capacitance had enhanced 69.9%, as high as 162.88F/g.

Sign in / Sign up

Export Citation Format

Share Document