scholarly journals Performance Improvement of Supercapacitor Materials with Crushed 3D Structured Graphene

2022 ◽  
Author(s):  
Akter H. Reaz ◽  
SHIMUL SAHA ◽  
Chanchal Kumar Roy ◽  
M. Mozammal Hosen ◽  
Tanmay Sarker Shuvo ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Electrode Materials ◽  
Acid Leaching ◽  
Poor Performance ◽  
Electrode System ◽  
Electrochemical Performances ◽  
Initial Value ◽  
3D Graphene ◽  
Graphene Structures ◽  
A Current

Abstract Conventional 2D-graphene sheets (2D-rGO) often demonstrate poor performance as capacitor materials, especially in cyclability due to the lamellar stacking and agglomeration of the electrode materials. Herein, we have proposed that crushed 3D-graphene (c-3D-rGO) can overcome the limitation. A simplistic way to prepare 3D-crushed graphene structures has been presented utilizing metal rGO core-shell (Ni@rGO) followed by acid leaching. The electrochemical performances of the prepared c-3D-rGO were evaluated as capacitor material using a three-electrode system with aqueous 0.5 M Na2SO4 solution through cyclic voltammetry and galvanostatic charge-discharge measurements. 2D-rGO was separately prepared to compare the performance with 3D-crushed graphene structures. It has been observed that the calculated specific capacitance (Csp) value of the prepared c-3D-rGO was 335 Fg-1 at a current density of 0.15 Ag-1, which was about three times higher than that of the 2D-rGO. The c-3D-rGO electrode retained 100% capacitance of its initial value after 10000 cycles, demonstrating the material’s excellent electrochemical stability. Furthermore, to show the performance in hybrid capacitor, manganese oxide (MnOx) with c-3D-rGO. The presence of c-3D-rGO significantly improved the capacitive performance MnOx.

scholarly journals Electrochemical Features of Symmetric and Asymmetric Supercapacitors Based on Nanostructured Mn-Cuo Electrodes

2018 ◽  
Vol 34 (6) ◽  
pp. 3058-3063 ◽  
Author(s):  
R. Suresh ◽  
K. Tamilarasan ◽  
D. Senthil Vadivu
Keyword(s):  
Current Density ◽  
Material Science ◽  
Electrode Materials ◽  
Aqueous Electrolyte ◽  
Cyclic Stability ◽  
Initial Value ◽  
Asymmetric Supercapacitors ◽  
Supercapacitive Performance ◽  
Subsequent Investigation ◽  
A Current

Progress in material science has unearthed a number of options that offer great advantages for nanostructured electrode materials which enable supercapacitors to operate efficiently. Present work involves fabrication of symmetric and asymmetric type supercapacitor devices utilizing Mn-CuO nanostructures and activated carbon (AC) as electrode materials and subsequent investigation on their supercapacitive performance in 2M KOH aqueous electrolyte. The asymmetric supercapacitor device (Mn-CuO // 2M KOH// AC) demonstrate a specific capacitance of 72 Fg-1 at a current density of 0.5 Ag-1. The cyclic stability test of this device performed at a current density of 10 Ag-1 reveals a capacitance retention of 71% of its initial value over 300 charge-discharge cycles. In addition, this device exhibits an energy density of 7.4 Whkg-1 and a power density of 127 Wkg-1.

scholarly journals Preparation of Porous Activated Carbons for High Performance Supercapacitors from Taixi Anthracite by Multi-Stage Activation

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3588 ◽  
Author(s):  
Xiao-Ming Yue ◽  
Zhao-Yang An ◽  
Mei Ye ◽  
Zi-Jing Liu ◽  
Cui-Cui Xiao ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
High Performance ◽  
Electrode Materials ◽  
Activated Carbons ◽  
High Rank ◽  
Cycle Performance ◽  
Electrochemical Performances ◽  
Multi Stage ◽  
A Current

Coal-based porous materials for supercapacitors were successfully prepared using Taixi anthracite (TXA) by multi-stage activation. The characterization and electrochemical tests of activated carbons (ACs) prepared in different stages demonstrated that the AC from the third-stage activation (ACIII) shows good porous structures and excellent electrochemical performances. ACIII exhibited a fine specific capacitance of 199 F g−1 at a current density of 1 A g−1 in the three-electrode system, with 6 mol L−1 KOH as the electrolyte. The specific capacitance of ACIII remained 190 F g−1 even despite increasing the current density to 5 A g−1, indicating a good rate of electrochemical performance. Moreover, its specific capacitance remained at 98.1% of the initial value after 5000 galvanostatic charge-discharge (GCD) cycle tests at a current density of 1 A g−1, suggesting that the ACIII has excellent cycle performance as electrode materials for supercapacitors. This study provides a promising approach for fabricating high performance electrode materials from high-rank coals, which could facilitate efficient and clean utilization of high-rank coals.

Facile Synthesis of Co3O4/Nitrogen-Doped Graphene Composite and their Electrochemical Performances

2015 ◽  
Vol 1120-1121 ◽  
pp. 347-351
Author(s):  
Wen Xiao Bao ◽  
Qian Long Zhou ◽  
Tian Yu Zhang ◽  
Wei Long Li ◽  
Zhao Yu Ren
Keyword(s):  
Current Density ◽  
Electrode Materials ◽  
Electrochemical Performances ◽  
Cycle Stability ◽  
Facile Synthesis ◽  
Nitrogen Doped ◽  
Graphene Composite ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
A Current

Co3O4/Nitrogen-doped graphene (Co3O4/NG) composites were synthesized by a simple hydrothermal method. The Co3O4/NG composites show a better electrochemical performance than the Co3O4/graphene (Co3O4/G) composite. The specific capacitance of Co3O4/NG electrode is 428 F/g (290 F/g for Co3O4/G electrode) at a current density of 1 A/g. As the current density was increased from 1 to 8 A/g, the capacitance of Co3O4/NG still retained 57%, significantly larger than that of Co3O4/G (40%). Moreover, over 94% of the original capacitance was maintained after 500 cycles (72% for Co3O4/G electrode), indicating a good cycle stability of Co3O4/NG electrode materials.

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.

scholarly journals Aluminum substitution for vanadium in the Na3V2(PO4)2F3 and Na3V2(PO4)2FO2 type materials

2019 ◽  
Vol 55 (78) ◽  
pp. 11719-11722 ◽  
Author(s):  
Jacob Olchowka ◽  
Long H. B. Nguyen ◽  
Thibault Broux ◽  
Paula Sanz Camacho ◽  
Emmanuel Petit ◽  
...  
Keyword(s):  
Structural Properties ◽  
Electrode Materials ◽  
Positive Electrode ◽  
Electrochemical Performances ◽  
Al Substitution ◽  
Aluminum Substitution ◽  
Positive Electrode Materials

Investigation of the effects of Al substitution for V on the structural properties and electrochemical performances for two of the most promising positive electrode materials for Na-ion batteries, Na3V2(PO4)2F3 and Na3V2(PO4)2FO2.

scholarly journals Enhanced Electrochemical Performances of Hollow-Structured N-Doped Carbon Derived from a Zeolitic Imidazole Framework (ZIF-8) Coated by Polydopamine as an Anode for Lithium-Ion Batteries

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2436
Author(s):  
Da-Won Lee ◽  
Achmad Yanuar Maulana ◽  
Chaeeun Lee ◽  
Jungwook Song ◽  
Cybelle M. Futalan ◽  
...  
Keyword(s):  
Carbon Materials ◽  
Hollow Structure ◽  
Lithium Ion ◽  
Reversible Capacity ◽  
Electrical Performance ◽  
Electrochemical Performances ◽  
Effective Surface ◽  
Voltage Range ◽  
Hollow Structures ◽  
A Current

Doping heteroatoms such as nitrogen (N) and boron (B) into the framework of carbon materials is one of the most efficient methods to improve the electrical performance of carbon-based electrodes. In this study, N-doped carbon has been facilely synthesized using a ZIF-8/polydopamine precursor. The polyhedral structure of ZIF-8 and the effective surface-coating capability of dopamine enabled the formation of N-doped carbon with a hollow structure. The ZIF-8 polyhedron served as a sacrificial template for hollow structures, and dopamine participated as a donor of the nitrogen element. When compared to ZIF-8-derived carbon, the HSNC electrode showed an improved reversible capacity of approximately 1398 mAh·g−1 after 100 cycles, with excellent cycling retention at a voltage range of 0.01 to 3.0 V using a current density of 0.1 A·g−1.

Treatment of As(V) and As(III) by electrocoagulation using Al and Fe electrode

2009 ◽  
Vol 60 (5) ◽  
pp. 1341-1346 ◽  
Author(s):  
W. H. Kuan ◽  
C. Y. Hu ◽  
M. C. Chiang
Keyword(s):  
Passive Film ◽  
Potentiodynamic Polarization ◽  
Electrode Materials ◽  
Initial Period ◽  
Electrode System ◽  
Initial Solution ◽  
Alkaline Condition ◽  
Bipolar Electrode ◽  
Pitting Potential ◽  
Fe Hydroxide

A batch electrocoagulation (EC) process with bipolar electrode and potentiodynamic polarization tests with monopolar systems were investigated as methods to explore the effects of electrode materials and initial solution pH on the As(V) and As(III) removal. The results displayed that the system with Al electrode has higher reaction rate during the initial period from 0 to 25 minutes than that of Fe electrode for alkaline condition. The pH increased with the EC time because the As(V) and As(III) removal by either co-precipitation or adsorption resulted in that the OH positions in Al-hydroxide or Fe-hydroxide were substituted by As(V) and As(III). The pH in Fe electrode system elevate higher than that in Al electrode because the As(V) removal substitutes more OH position in Fe-hydroxide than that in Al-hydroxide. EC system with Fe electrode can successfully remove the As(III) but system with Al electrode cannot because As(III) can strongly bind to the surface of Fe-hydroxide with forming inner-sphere species but weakly adsorb to the Al-hydroxide surface with forming outer-sphere species. The acidic solution can destroy the deposited hydroxide passive film then allow the metallic ions liberate into the solution, therefore, the acidic initial solution can enhance the As(V) and As(III) removal. The over potential calculation and potentiodynamic polarization tests reveal that the Fe electrode systems possess higher over potential and pitting potential than that of Al electrode system due to the fast hydrolysis of and the occurrence of Fe-hydroxide passive film.

scholarly journals Investigation on the Mass Distribution and Chemical Compositions of Various Ionic Liquids-Extracted Coal Fragments and Their Effects on the Electrochemical Performance of Coal-Derived Carbon Nanofibers (CCNFs)

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 664
Author(s):  
Shuai Tan ◽  
Theodore John Kraus ◽  
Mitchell Ross Helling ◽  
Rudolph Kurtzer Mignon ◽  
Franco Basile ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Electrochemical Performance ◽  
Carbon Nanofibers ◽  
Mass Distribution ◽  
Electrode Materials ◽  
Gas Chromatography Mass Spectrometry ◽  
Electrochemical Performances ◽  
Diffusion Resistance ◽  
Chemical Compositions ◽  
Holistic Understanding

Coal-derived carbon nanofibers (CCNFs) have been recently found to be a promising and low-cost electrode material for high-performance supercapacitors. However, the knowledge gap still exists between holistic understanding of coal precursors derived from different solvents and resulting CCNFs’ properties, prohibiting further optimization of their electrochemical performance. In this paper, assisted by laser desorption/ionization (LDI) and gas chromatography–mass spectrometry (GC–MS) technologies, a systematic study was performed to holistically characterize mass distribution and chemical composition of coal precursors derived from various ionic liquids (ILs) as extractants. Sequentially, X-ray photoelectron spectroscopy (XPS) revealed that the differences in chemical properties of various coal products significantly affected the surface oxygen concentrations and certain species distributions on the CCNFs, which, in turn, determined the electrochemical performances of CCNFs as electrode materials. We report that the CCNF that was produced by an oxygen-rich coal fragment from C6mimCl ionic liquid extraction showed the highest concentrations of quinone and ester groups on the surface. Consequentially, C6mimCl-CCNF achieved the highest specific capacitance and lowest ion diffusion resistance. Finally, a symmetric carbon/carbon supercapacitor fabricated with such CCNF as electrode delivered an energy density of 21.1 Wh/kg at the power density of 0.6 kW/kg, which is comparable to commercial active carbon supercapacitors.

ZIF-67-derived NiCo2O4@Co2P/Ni2P honeycomb nanosheets on carbon cloth for high-performance asymmetric supercapacitors

2021 ◽  
Author(s):  
Wen-Wei Song ◽  
Bing Wang ◽  
Xiao-Man Cao ◽  
Qiang Chen ◽  
Zhengbo Han
Keyword(s):  
Transition Metal ◽  
Transition Metal Oxides ◽  
High Performance ◽  
Electrode Materials ◽  
Redox Activity ◽  
Electrochemical Performances ◽  
Carbon Cloth ◽  
Metal Phosphides ◽  
Metal Organic ◽  
Transition Metal Phosphides

Metal-organic frameworks (MOFs)-derived transition-metal oxides and transition-metal phosphides have great application potential as electrode materials for supercapacitors, owing to the excellent redox activity and high conductivity. However, their electrochemical performances...

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