scholarly journals Prepared MnO2 with different crystal forms as electrode materials for supercapacitors: experimental research from hydrothermal crystallization process to electrochemical performances

RSC Advances ◽  
2017 ◽  
Vol 7 (64) ◽  
pp. 40286-40294 ◽  
Author(s):  
Xiaoyu Zhao ◽  
Yongdan Hou ◽  
Yanfei Wang ◽  
Libin Yang ◽  
Liang Zhu ◽  
...  
Keyword(s):  
Manganese Dioxide ◽  
Hydrothermal Treatment ◽  
Experimental Research ◽  
Crystallization Process ◽  
Electrode Materials ◽  
Electrochemical Performances ◽  
Hydrothermal Crystallization ◽  
Crystal Forms ◽  
Ph Values ◽  
Time Periods

The aim of this study was to prepare manganese dioxide with different crystal forms through hydrothermal treatment of MnSO4·H2O–KMnO4 precursors at various precursor ratios, temperatures, time periods, and pH values.

Poly(aniline-co-pyrrole)-coated Ni-doped manganese dioxide as electrode materials for supercapacitors

2020 ◽  
Vol 13 (02) ◽  
pp. 2051007
Author(s):  
Jie Dong ◽  
Qinghao Yang ◽  
Qiuli Zhao ◽  
Zhenzhong Hou ◽  
Yue Zhou ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Manganese Dioxide ◽  
Specific Capacitance ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Mass Ratio ◽  
Scan Rate ◽  
Poly Aniline ◽  
Inorganic And Organic

Electrode materials with a high specific capacitance, outstanding reversibility and excellent cycle stability are constantly pursued for supercapacitors. In this paper, we present an approach to improve the electrochemical performance by combining the advantages of both inorganic and organic. Ni-MnO2/PANi-co-PPy composites are synthesized, with the copolymer of aniline/pyrrole being coated on the surface of Ni-doped manganese dioxide nanospheres. The inorganic–organic composite enables a substantial increase in its specific capacitance and cycle stability. When the mass ratio of Ni-MnO2 to aniline and pyrrole mixed monomer is 1:5, the composite delivers high specific capacitance of 445.49[Formula: see text]F/g at a scan rate of 2[Formula: see text]mV/s and excellent cycle stability of 61.65% retention after 5000 cycles. The results indicate that the Ni-MnO2/PANi-co-PPy composites are promising electrode materials for future supercapacitors application.

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 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.

The preparation and properties performance of lithium carbonate @ manganese dioxide @ white carbon black electrode materials

Ionics ◽  
2021 ◽  
Author(s):  
Xuchun Wang ◽  
Dongdong Ouyang ◽  
Qi Wang ◽  
Xuemei Zhang ◽  
Qianrui Liu ◽  
...  
Keyword(s):  
Carbon Black ◽  
Manganese Dioxide ◽  
Electrode Materials ◽  
Lithium Carbonate

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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