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

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.

Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2176
Author(s):  
Deepa Guragain ◽  
Sunil Karna ◽  
Jonghyun Choi ◽  
Romakanta Bhattarai ◽  
Tej P. Poudel ◽  
...  

In this study, hydrothermally produced Fe-doped Co3O4 nanostructured particles are investigated as electrocatalysts for the water-splitting process and electrode materials for supercapacitor devices. The results of the experiments demonstrated that the surface area, specific capacitance, and electrochemical performance of Co3O4 are all influenced by Fe3+ content. The FexCo3-xO4 with x = 1 sample exhibits a higher BET surface (87.45 m2/g) than that of the pristine Co3O4 (59.4 m2/g). Electrochemical measurements of the electrode carried out in 3 M KOH reveal a high specific capacitance of 153 F/g at a current density of 1 A/g for x = 0.6 and 684 F/g at a 2 mV/s scan rate for x = 1.0 samples. In terms of electrocatalytic performance, the electrode (x = 1.0) displayed a low overpotential of 266 mV (at a current density of 10 mA/cm2) along with 52 mV/dec Tafel slopes in the oxygen evolution reaction. Additionally, the overpotential of 132 mV (at a current density of 10 mA/cm2) and 109 mV with 52 mV/dec Tafel slope were obtained for x = 0.6 sample towards hydrogen evolution reaction (HER). According to electrochemical impedance spectroscopy (EIS) measurements and the density functional theory (DFT) study, the addition of Fe3+ increased the conductivity at the electrode–electrolyte interface, which substantially impacted the high activity of the iron-doped cobalt oxide. The electrochemical results revealed that the mesoporous Fe-doped Co3O4 nanostructure could be used as potential electrode material in the high-performance electrochemical capacitor and water-splitting catalysts.


2020 ◽  
Vol 13 (02) ◽  
pp. 2051007
Author(s):  
Jie Dong ◽  
Qinghao Yang ◽  
Qiuli Zhao ◽  
Zhenzhong Hou ◽  
Yue Zhou ◽  
...  

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.


2017 ◽  
Vol 20 (4) ◽  
pp. 197-204
Author(s):  
Weiliang Chen ◽  
Shuhua Pang ◽  
Zheng Liu ◽  
Zhewei Yang ◽  
Xin Fan ◽  
...  

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.


2021 ◽  
Vol 16 (6) ◽  
pp. 891-904
Author(s):  
Xiang-Sen Meng ◽  
Jun Xiang ◽  
Nan Bu ◽  
Yan Guo ◽  
Sroeurb Loy ◽  
...  

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.


Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3588 ◽  
Author(s):  
Xiao-Ming Yue ◽  
Zhao-Yang An ◽  
Mei Ye ◽  
Zi-Jing Liu ◽  
Cui-Cui Xiao ◽  
...  

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.


NANO ◽  
2019 ◽  
Vol 14 (07) ◽  
pp. 1950085 ◽  
Author(s):  
Puhong Wen ◽  
Jingjing Guo ◽  
Lijun Ren ◽  
Chuanchuan Wang ◽  
Yuzhu Lan ◽  
...  

1D [Formula: see text]-MoO3 nanobelts were prepared using ammonium heptamolybdate tetrahydrate [(NH[Formula: see text]Mo7O[Formula: see text]H2O] as raw material by one-step hydrothermal method without template or guide agent at 180∘C. The layered [Formula: see text]-MoO3 nanobelt electrode has favorable electrochemical performance, and displays a fairly high specific capacitance, which can be up to 445[Formula: see text]F/g at a current density of 0.5[Formula: see text]A/g.


2014 ◽  
Vol 50 (76) ◽  
pp. 11188-11191 ◽  
Author(s):  
Peng Yuan ◽  
Ning Zhang ◽  
Dan Zhang ◽  
Tao Liu ◽  
Limiao Chen ◽  
...  

Nickel foam supported Zn–Co hydroxide nanoflakes were fabricated by a facile solvothermal method, which exhibited excellent specific capacitance and remarkable cycling stability as electrode materials in supercapacitors.


Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1425
Author(s):  
Di Jiang ◽  
Chuanying Wei ◽  
Ziyang Zhu ◽  
Xiaohui Xu ◽  
Min Lu ◽  
...  

Metal organic frameworks (MOFs) have been rapidly developed in the application of electrode materials due to their controllable morphology and ultra-high porosity. In this research, flower-like layered nickel-based bimetallic MOFs microspheres with different metal central ions were synthesized by solvothermal method. Compared with Ni-MOFs, the optimization of the specific capacitance of NiCo-MOFs and NiMn-MOFs was been confirmed. For example, the specific capacitance of NiCo-MOFs can reach 882 F·g−1 at 0.5 A·g−1 while maintaining satisfactory cycle life (the specific capacity remains 90.1% of the initial value after 3000 charge-discharge cycles at 5 A·g−1). In addition, the NiCo-MOFs//AC HSCs, which are composed of NiCo-MOFs and activated carbon (AC), achieved a maximum energy density of 18.33 Wh·kg−1 at a power density of 400 W·kg−1, and showed satisfactory cycle life (82.4% after 3000 cycles). These outstanding electrochemical properties can be ascribed to the synergistic effect between metal ions, the optimized conductivity, and the unique layered stacked flower structure, which provides a smooth transmission channel for electrons/ions. In addition, this research gives a general method for the application of MOFs in the field of supercapacitors.


2018 ◽  
Vol 34 (6) ◽  
pp. 3058-3063 ◽  
Author(s):  
R. Suresh ◽  
K. Tamilarasan ◽  
D. Senthil Vadivu

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.


2016 ◽  
Vol 40 (8) ◽  
pp. 6881-6889 ◽  
Author(s):  
Cuiping Yu ◽  
Yan Wang ◽  
Jianfang Zhang ◽  
Xia Shu ◽  
Jiewu Cui ◽  
...  

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.


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