Ultrahigh energy density asymmetric electrochemical capacitors based on flower-like ZnO/Co3O4 nanobundle arrays and stereotaxically constricted graphene

2019 ◽  
Vol 7 (3) ◽  
pp. 1273-1280 ◽  
Author(s):  
Ning Hu ◽  
Wen Hao Gong ◽  
Lei Huang ◽  
Pei Kang Shen
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Current Density ◽  
Electrochemical Capacitors ◽  
Ultrahigh Energy ◽  
Facile Hydrothermal Method ◽  
A Current

Unique hierarchical flower-like ZnO/Co3O4 nanobundle arrays were synthesized via a facile hydrothermal method and the electrode shows remarkable specific capacitance up to 1983 F g−1 at a current density of 2 A g−1.

Co3S4/NiCo2S4 Nano-Arrays on Nickel Foam as Energy Storage for Supercapacitors

2021 ◽  
Vol 16 (6) ◽  
pp. 891-904
Author(s):  
Xiang-Sen Meng ◽  
Jun Xiang ◽  
Nan Bu ◽  
Yan Guo ◽  
Sroeurb Loy ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Density ◽  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Current Density ◽  
Retention Rate ◽  
Nickel Foam ◽  
Maximum Energy ◽  
Capacity Retention ◽  
A Current

In this work, Co3S4/NiCo2S4 nano-arrays electrode with Co3S4 nanocones and NiCo2S4 nanosheets interlaced arrangement are prepared by the promising hydrothermal method. Compared with single Co3S4/NF or NiCo2S4/NF electrode, the prepared Co3S4/NiCo2S4/NF electrode exhibits excellent specific capacitance. At a current density of 2 mA cm−2, the surface capacitance is as high as 9036 mF cm−2, and it still maintains a surface capacitance of 5664 mF cm−2 at a current density of 8 mA cm−2. Co3S4/NiCo2S4/NF||ASC has a high electrochemical performance with a maximum energy density of 0.62 Wh cm−3 and a power density of 15.94 W cm−3. At a current density of 5 mA cm−2, the capacity retention rate is 83.75% after 3000 cycles.

scholarly journals One step synthesis of Ni/Ni(OH)2 nano sheets (NSs) and their application in asymmetric supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 5898-5911 ◽  
Author(s):  
Sivasankara Rao Ede ◽  
S. Anantharaj ◽  
K. T. Kumaran ◽  
Soumyaranjan Mishra ◽  
Subrata Kundu
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Maximum Energy ◽  
Reducing Agent ◽  
Asymmetric Supercapacitors ◽  
Facile Hydrothermal Method ◽  
One Step ◽  
Asymmetric Device

Ni/Ni(OH)2 NSs were prepared by a facile hydrothermal method using EtOH as reducing agent. Asymmetric device is fabricated using AC and Ni/Ni(OH)2 NSs as electrodes, with optimized specific capacitance of 62 F g−1 and a maximum energy density of 23.45 W h kg−1.

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

2016 ◽  
Vol 848 ◽  
pp. 396-400
Author(s):  
Zhong Yang Wang ◽  
Run Hua Fan ◽  
Qian Qian Li ◽  
Lei Qian
Keyword(s):  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Current Density ◽  
Electrochemical Analysis ◽  
Electrical Impedance Spectroscopy ◽  
X Ray Diffraction ◽  
Redox Peak ◽  
Capacitive Properties ◽  
Eis Measurements ◽  
A Current

The precursor Ni (OH)2 was synthesized by a simple hydrothermal method with NiSO4•6H2O and (CH2)6N4 as reactants. Both concentrations of reactants are 0.02 M, 0.04 M, 0.06 M, 0.08 M for experiment contrast, and then NiO was gained after calcination at 400°C. The phase and morphology of the synthesized product were characterized by X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM). The electrochemical capacitive characterization was performed using cyclic voltammetry (CV), galvanostatic charge/discharge (GCD) and electrical impedance spectroscopy (EIS) measurements in a 6mol/L KOH aqueous solution electrolyte. The result shows that with the increase of concentrations of reactants, nanosheets stack together and turn into thick slices. CV curves have obvious redox peak, the GCD curves are nonlinear and EIS curves of high frequency area are semicircle. From electrochemical analysis, the capacitance type is pseudocapacitance. And a maximal specific capacitance value when two reactants concentration both are 0.08 M which the specific capacitance decreases from 97 F/g (at a current density of 0.3A/g) to 56 F/g (at a current density of 1 A/g).

Design and synthesis of hierarchical NiCo2S4@NiMoO4core/shell nanospheres for high-performance supercapacitors

2015 ◽  
Vol 39 (11) ◽  
pp. 8430-8438 ◽  
Author(s):  
Mingming Yao ◽  
Zhonghua Hu ◽  
Yafei Liu ◽  
Peipei Liu
Keyword(s):  
Specific Capacitance ◽  
Hydrothermal Method ◽  
Current Density ◽  
Electrode Material ◽  
High Performance ◽  
Three Dimensional ◽  
High Specific Capacitance ◽  
Core Shell ◽  
Design And Synthesis ◽  
A Current

A novel electrode material of three-dimensional hierarchical NiCo2S4@NiMoO4core/shell nanospheres was synthesized by a facile two-step hydrothermal method. These hierarchical NiCo2S4@NiMoO4core/shell nanospheres exhibit a high specific capacitance of 1714 F g−1at a current density of 1 A g−1, which indicated the excellent electrochemistry performance.

scholarly journals A Hierarchical Architecture of Functionalized Polyaniline/Manganese Dioxide Composite with Stable-Enhanced Electrochemical Performance

2021 ◽  
Vol 5 (5) ◽  
pp. 129
Author(s):  
Yapeng Wang ◽  
Yanxiang Wang ◽  
Chengjuan Wang ◽  
Yongbo Wang
Keyword(s):  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrode Materials ◽  
High Efficiency ◽  
Scanning Speed ◽  
Hierarchical Architecture ◽  
Electrochemical Window ◽  
A Current

As one of the most outstanding high-efficiency and environmentally friendly energy storage devices, the supercapacitor has received extensive attention across the world. As a member of transition metal oxides widely used in electrode materials, manganese dioxide (MnO2) has a huge development potential due to its excellent theoretical capacitance value and large electrochemical window. In this paper, MnO2 was prepared at different temperatures by a liquid phase precipitation method, and polyaniline/manganese dioxide (PANI/MnO2) composite materials were further prepared in a MnO2 suspension. MnO2 and PANI/MnO2 synthesized at a temperature of 40 °C exhibit the best electrochemical performance. The specific capacitance of the sample MnO2-40 is 254.9 F/g at a scanning speed of 5 mV/s and the specific capacitance is 241.6 F/g at a current density of 1 A/g. The specific capacitance value of the sample PANI/MnO2-40 is 323.7 F/g at a scanning speed of 5 mV/s, and the specific capacitance is 291.7 F/g at a current density of 1 A/g, and both of them are higher than the specific capacitance value of MnO2. This is because the δ-MnO2 synthesized at 40 °C has a layered structure, which has a large specific surface area and can accommodate enough electrolyte ions to participate the electrochemical reaction, thus providing sufficient specific capacitance.

Integration of mesoporous nickel cobalt oxide nanosheets with ultrathin layer carbon wrapped TiO2 nanotube arrays for high-performance supercapacitors

2016 ◽  
Vol 40 (8) ◽  
pp. 6881-6889 ◽  
Author(s):  
Cuiping Yu ◽  
Yan Wang ◽  
Jianfang Zhang ◽  
Xia Shu ◽  
Jiewu Cui ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Cobalt Oxide ◽  
Current Density ◽  
High Performance ◽  
Tio2 Nanotube Arrays ◽  
Nanotube Arrays ◽  
Nickel Cobalt ◽  
Nickel Cobalt Oxide ◽  
A Current ◽  
Ultrathin Layer

Novel nanocomposite NiCo2O4/C-TNAs were synthesized for high-performance supercapacitors with a specific capacitance of 934.9 F g−1 at a current density of 2 A g−1.

Hierarchical Dendritic Polypyrrole with High Specific Capacitance for High-performance Supercapacitor Electrode Materials

2017 ◽  
Vol 20 (4) ◽  
pp. 197-204
Author(s):  
Weiliang Chen ◽  
Shuhua Pang ◽  
Zheng Liu ◽  
Zhewei Yang ◽  
Xin Fan ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
High Performance ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Chemical Oxidation ◽  
Channel Structure ◽  
Supercapacitor Electrode ◽  
Infrared Spectrometer ◽  
A Current

Polypyrrole with hierarchical dendritic structures assembled with cauliflower-like structure of nanospheres, was synthesized by chemical oxidation polymerization. The structure of polyryrrole was characterized by Fourier transform infrared spectrometer and scanning electron microscopy. The electrochemical performance was performed on CHI660 electrochemical workstation. The results show that oxalic acid has a significant effect on morphology of PPy products. The hierarchical dendritic PPyOA(3) electrodes possess a large specific capacitance as high as 744 F/g at a current density of 0.2 A/g and could achieve a higher specific capacitance of 362 F/g even at a current density of 5.0 A/g. Moreover, the dendritic PPy products produce a large surface area on the electrode through the formation of the channel structure with their assembled cauliflower-like morphology, which facilitates the charge/electron transfer relative to the spherical PPy electrode. The spherical dendritic PPyOA(3) electrode has 58% retention of initial specific capacitance after 260 cycles. The as-prepared dendritic polypyrrole with high performance is a promsing electrode material for supercapacitor.

Preparation of lignite-based activated carbon with high specific capacitance for electrochemical capacitors

2015 ◽  
Vol 08 (04) ◽  
pp. 1550031 ◽  
Author(s):  
Baolin Xing ◽  
Jianliang Cao ◽  
Yan Wang ◽  
Guiyun Yi ◽  
Chuanxiang Zhang ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Electron Microscope ◽  
Specific Capacitance ◽  
Current Density ◽  
Electrode Materials ◽  
High Current Density ◽  
Electrochemical Capacitors ◽  
High Specific Capacitance ◽  
High Current ◽  
Charge Discharge

A lignite-based activated carbon (LAC) for electrochemical capacitors (ECs) was prepared from high moisture lignite by KOH activation, and the as-prepared sample was characterized by the N 2-sorption, scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical performances of ECs with activated carbon as electrodes in 3 M KOH aqueous solution were evaluated by constant current charge-discharge and cyclic voltammetry. The LAC exhibits a well-developed surface area of 2581 m2/g, a relative wide pore size distribution of 0.5–10 nm. The ECs with LAC as electrode materials presents a high specific capacitance of 392 F/g at a low current density of 50 mA/g, and still remains 315 F/g even at a high current density of 5 A/g. The residual specific capacitance is as high as 92.9% after 2000 cycles. Compared with the commercial activated carbon (Maxsorb: Commercial product, Kansai, Japan), the LAC based electrode materials shows superior capacitive performance in terms of specific capacitance and charge–discharge performance at the high current density.

7,7,8,8-Tetracyanoquinodimethane-assisted one-step electrochemical exfoliation of graphite and its performance as an electrode material

Nanoscale ◽  
2014 ◽  
Vol 6 (9) ◽  
pp. 4864-4873 ◽  
Author(s):  
Partha Khanra ◽  
Chang-No Lee ◽  
Tapas Kuila ◽  
Nam Hoon Kim ◽  
Min Jun Park ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
Electrode Material ◽  
Functionalized Graphene ◽  
Electrochemical Exfoliation ◽  
Water Dispersible ◽  
Surface Modifiers ◽  
One Step ◽  
Modified Graphene ◽  
A Current

Water-dispersible functionalized graphene via one-step electrochemical exfoliation of graphite was prepared using 7,7,8,8-tetracyanoquinodimethane (TCNQ) anions as surface modifiers and electrolytes. The specific capacitance value of TCNQ-modified graphene measured with electrolytes (1 M KOH) was 324 F g−1 at a current density of 1 A g−1.

scholarly journals Electrochemical Performances Investigation of New Carbon-Coated Nickel Sulfides as Electrode Material for Supercapacitors

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3509 ◽  
Author(s):  
Xinyu Lei ◽  
Mu Li ◽  
Min Lu ◽  
Xiaohui Guan
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
Electrode Material ◽  
Rate Capability ◽  
Nitrogen Atmosphere ◽  
Electrochemical Performances ◽  
Discharge Process ◽  
Carbon Coated ◽  
Water Bath Heating ◽  
A Current

A new carbon-coated nickel sulfides electrode material (NST/CNTs@C) has been synthesized through an easy-to-operate process: NiS2/CNTs which was prepared by a hydrothermal method reacted with BTC (1,3,5-benzenetricarboxylic acid) under the condition of water bath heating to obtain the precursor, and then the precursor was calcined in 450 °C under a nitrogen atmosphere to obtain NST/CNTs@C. The electrochemical performance of NST/CNTs@C has been greatly improved because the formation of a carbon-coated layer effectively increased the specific surface area, reduced the charge transport resistance and inhibited the morphological change of nickel sulfides in the charge–discharge process. Compared with pure NiS2 and NiS2/CNTs, NST/CNTs@C presented great specific capacitance (620 F·g−1 at a current density of 1 A·g−1), better cycle stability (49.19% capacitance retention after 1000 cycles) and more superior rate capability (when the current density was raised to 10 A·g−1 the specific capacitance remained 275 F·g−1).

Sign in / Sign up

Export Citation Format

Share Document