Facile and low-cost fabrication of nanostructured NiCo2O4 spinel with high specific capacitance and excellent cycle stability

2012 ◽  
Vol 63 ◽  
pp. 220-227 ◽  
Author(s):  
Changhui Wang ◽  
Xiong Zhang ◽  
Dacheng Zhang ◽  
Chao Yao ◽  
Yanwei Ma
Keyword(s):  
Specific Capacitance ◽  
Low Cost ◽  
High Specific Capacitance ◽  
Cycle Stability

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 Synthesis of Hierarchical Porous Ni1.5Co1.5S4/g-C3N4 Composite for Supercapacitor with Excellent Cycle Stability

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1631
Author(s):  
Fangzhou Jin ◽  
Xingxing He ◽  
Jinlong Jiang ◽  
Weijun Zhu ◽  
Jianfeng Dai ◽  
...  
Keyword(s):  
Current Density ◽  
High Current Density ◽  
Low Cost ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Cycle Stability ◽  
Hydrothermal Route ◽  
Supercapacitor Application ◽  
Hierarchical Porous

In this work, the hierarchical porous Ni1.5Co1.5S4/g-C3N4 composite was prepared by growing Ni1.5Co1.5S4 nanoparticles on graphitic carbon nitride (g-C3N4) nanosheets via a hydrothermal route. Due to the self-assembly of larger size g-C3N4 nanosheets as a skeleton, the prepared nanocomposite possesses a unique hierarchical porous structure that can provide short ions diffusion and fast electron transport. As a result, the Ni1.5Co1.5S4/g-C3N4 composite exhibits a high specific capacitance of 1827 F g−1 at a current density of 1 A g−1, which is 1.53 times that of pure Ni1.5Co1.5S4 (1191 F g−1). In particular, the Ni1.5Co1.5S4/g-C3N4//activated carbon (AC) asymmetric supercapacitor delivers a high energy density of 49.0 Wh kg−1 at a power density of 799.0 W kg−1. Moreover, the assembled device shows outstanding cycle stability with 95.5% capacitance retention after 8000 cycles at a high current density of 10 A g−1. The attractive performance indicates that the easily synthesized and low-cost Ni1.5Co1.5S4/g-C3N4 composite would be a promising electrode material for supercapacitor application.

N-doped porous carbon derived from walnut shells with enhanced electrochemical performance for supercapacitor

2019 ◽  
Vol 12 (03) ◽  
pp. 1950042 ◽  
Author(s):  
Yunfeng Wang ◽  
Honghui Jiang ◽  
Shewen Ye ◽  
Jiaming Zhou ◽  
Jiahao Chen ◽  
...  
Keyword(s):  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Porous Carbon ◽  
Low Cost ◽  
High Specific Capacitance ◽  
Cycling Stability ◽  
Electrochemical Performances ◽  
Walnut Shells ◽  
Electrochemical Cycling ◽  
Elemental Doping

As the low-cost, natural multi-component for elemental doping and environment-friendly characteristics, biomass-derived porous carbon for energy storage attracts intense attention. Herein, walnut shells-based porous carbon has been obtained through carbonization, hydrothermal and activation treatment. The corresponding porous carbon owns superior electrochemical performances with specific capacitance reaching up to 462[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text], and shows excellent cycling stability (5000 cycles, [Formula: see text]94.2% of capacitance retention at 10[Formula: see text]A[Formula: see text]g[Formula: see text]). Moreover, the symmetry supercapacitor achieves high specific capacitance (197[Formula: see text]F[Formula: see text]g[Formula: see text] at 1[Formula: see text]A[Formula: see text]g[Formula: see text]), relevant electrochemical cycling stability (5000 cycles, 89.2% of capacitance retention at 5[Formula: see text]A[Formula: see text]g[Formula: see text]) and high power/energy density (42.8[Formula: see text]W[Formula: see text]h[Formula: see text]kg[Formula: see text] at 1249[Formula: see text]W[Formula: see text]kg[Formula: see text]). Therefore, the facile synthesis approach and superb electrochemical performance ensure that the walnut shells-derived porous carbon is a promising electrode material candidate for supercapacitors.

Facile synthesis of exfoliated Co–Al LDH–carbon nanotube composites with high performance as supercapacitor electrodes

2014 ◽  
Vol 16 (33) ◽  
pp. 17936-17942 ◽  
Author(s):  
Lei Yu ◽  
Nannan Shi ◽  
Qi Liu ◽  
Jun Wang ◽  
Bin Yang ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Specific Capacitance ◽  
High Performance ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Facile Synthesis ◽  
Nanotube Composites ◽  
Carbon Nanotube Composites

A novel sandwich-like structured Co–Al LDH–CNT composite has been successfully synthesized. The as-prepared Co–Al LDHs–CNTs composite exhibites a high specific capacitance and a good cycle stability over 2000 cycles

scholarly journals Direct Synthesis of MnO2 Nanorods on Carbon Cloth as Flexible Supercapacitor Electrode

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Shuang Xi ◽  
Yinlong Zhu ◽  
Yutu Yang ◽  
Ying Liu
Keyword(s):  
Specific Capacitance ◽  
Low Cost ◽  
Direct Synthesis ◽  
High Specific Capacitance ◽  
Deposition Process ◽  
High Mass ◽  
Electrochemical Performances ◽  
Carbon Cloth ◽  
Supercapacitor Electrode ◽  
Flexible Supercapacitors

MnO2 nanorod/carbon cloth (MnO2/CC) composites were prepared through in situ redox deposition as freestanding electrodes for flexible supercapacitors. The CC substrates possessing porous and interconnecting structures enable the uniform decoration of MnO2 nanorods on each fiber, thus forming conformal coaxial micro/nanocomposites. Three-dimensional CC can provide considerable specific surface area for high mass loading of MnO2, and the direct deposition process without using polymeric binders enables reliable electrical connection of MnO2 with CC. The effect of MnO2 decoration on the electrochemical performances was further investigated, indicating that the electrode prepared with 40 min deposition time shows high specific capacitance (220 F/g at a scan rate of 5 mV/s) and good cycling property (90% of the initial specific capacitance was maintained after 2500 cycles) in 1 M Na2SO4 aqueous solution. This enhanced electrochemical performance is ascribed to the synergistic effect of good conductivity of carbon substrates as well as outstanding pseudocapacitance of MnO2 nanorods. The obtained MnO2/CC compositing electrode with the advantages of low cost and easy fabrication is promising in applications of flexible supercapacitors.

Bead chain structure RFC/ACF by electrospinning for supercapacitors

2019 ◽  
Vol 48 (5) ◽  
pp. 439-448
Author(s):  
Lei Guo ◽  
Lien Zhu ◽  
Lei Ma ◽  
Jian Zhang ◽  
QiuYu Meng ◽  
...  
Keyword(s):  
Composite Material ◽  
Specific Surface ◽  
Specific Capacitance ◽  
Surface Area ◽  
Specific Surface Area ◽  
Carbon Fibers ◽  
High Specific Capacitance ◽  
Chain Structure ◽  
Cycle Stability ◽  
Content Type

Purpose The purpose of this paper is to prepare a spherical modifier-modified activated carbon fiber of high specific capacitance intended for electrode materials of supercapacitor. Design/methodology/approach In this study, phenolic-based microspheres are taken as modifiers to prepare PAN-based fiber composites by electrospinning, pre-oxidation and carbonization. Pearl-chain structures appear in RFC/ACF composites, and pure polyacrylonitrile fibers show a dense network. The shape and cross-linking degree are large. After the addition of the phenolic-based microspheres, the composite material exhibits a layered pearlite chain structure with a large porosity, and the RFC/ACF composite material is derived because of the existence of a large number of bead chain structures in the composite material. The density increases, the volume declines and the mass after being assembled into a supercapacitor as a positive electrode material decreases. The specific surface area of RFC/ACF composites is increased as compared to pure fibers. The increase in specific surface area could facilitate the diffusion of electrolyte ions in the material. Owing to the large number of bead chains, plenty of pore channels are provided for the diffusion of electrolyte ions, which is conducive to enhancing the electrochemical performance of the composite and improving the RFC/ACF composite and the specific capacitance of the material. The methods of electrochemical testing on symmetric supercapacitors (as positive electrodes) are three-electrode cyclic voltammetry, alternating current impedance and cycle stability. Findings The specific capacitance value of the composite material was found to be 389.2 F/g, and the specific capacitance of the electrode operating at a higher current density of 20 mA/cm2 was 11.87 F/g (the amount of the microsphere modifier added was 0.3 g). Using this material as a positive electrode to assemble into asymmetrical supercapacitor, after 2,000 cycles, the specific capacitance retention rate was 87.46 per cent, indicating excellent cycle stability performance. This result can be attributed to the fact that the modifier embedded in the fiber changes the porosity between the fibers, while improving the utilization of the carbon fibers and making it easier for electrolyte ions to enter the interior of the composites, thereby increasing the capacitance of the composites. Originality/value The modified PAN-based activated carbon fibers in the study had high specific surface area and significantly high specific capacitance, which makes it applicable as an efficient and environment-friendly absorbent, as well as an advanced electrode material for supercapacitor.

The synthesis of shape-controlled α-MoO3/graphene nanocomposites for high performance supercapacitors

2015 ◽  
Vol 39 (11) ◽  
pp. 8780-8786 ◽  
Author(s):  
Jinhua Zhou ◽  
Juan Song ◽  
Huihua Li ◽  
Xiaomiao Feng ◽  
Zhendong Huang ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
High Performance ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Graphene Nanocomposites ◽  
Shape Controlled

Novel nanoflake-like α-MoO3/graphene nanocomposites were synthesized and exhibited a high specific capacitance of up to 360 F g−1 and excellent long term cycle stability.

A redox-mediated 3D graphene based nanoscoop design for ultracapacitor applications

2017 ◽  
Vol 41 (16) ◽  
pp. 8390-8398
Author(s):  
Pallavi Rani ◽  
Suman Kumari Jhajharia ◽  
Kaliaperumal Selvaraj
Keyword(s):  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Cycle Stability ◽  
Redox Species ◽  
3D Graphene

The judicious design of 3D graphene with a unique nanostructure blended with an active redox species demonstrates the ability to boost capacitance as high as 8-fold. This design not only exhibits high specific capacitance but also sustains it with a good cycle stability of even beyond 5000 cycles.

Flexible symmetrical planar supercapacitors based on multi-layered MnO2/Ni/graphite/paper electrodes with high-efficient electrochemical energy storage

2014 ◽  
Vol 2 (9) ◽  
pp. 2985-2992 ◽  
Author(s):  
Jin-Xian Feng ◽  
Qi Li ◽  
Xue-Feng Lu ◽  
Ye-Xiang Tong ◽  
Gao-Ren Li
Keyword(s):  
Energy Storage ◽  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Electrochemical Energy Storage ◽  
Storage Device ◽  
Energy Storage Device ◽  
Cycle Stability ◽  
Electrodeposition Method ◽  
High Efficient ◽  
Electrochemical Energy

We develop a cheap and simple drawing-electrodeposition method to fabricate highly flexible MnO2/Ni/graphite/paper electrodes and assemble a paper-based energy storage device with high specific capacitance and excellent cycle stability.

Facile synthesis of γ-MnO2/rice husk-based-activated carbon and its electrochemical properties

2017 ◽  
Vol 10 (05) ◽  
pp. 1750057 ◽  
Author(s):  
Xiaolan Song ◽  
Hailong Duan ◽  
Ying Zhang ◽  
Haibo Wang ◽  
Hongyun Cao
Keyword(s):  
Activated Carbon ◽  
Specific Capacitance ◽  
Low Cost ◽  
Chemical Deposition ◽  
Electrochemical Capacitor ◽  
High Specific Capacitance ◽  
Charge Transfer Resistance ◽  
Electrochemical Performances ◽  
Equivalent Series Resistance ◽  
Transfer Resistance

In this study, composite [Formula: see text]-MnO2/activated carbon (AC) was prepared by chemical deposition method, and then it was assembled into electrode and electrochemical capacitor. Effects of reaction temperature and MnO2 content were studied. Materials were characterized by X-ray diffraction, scanning electron microscope and electrochemical test. MnO2 prepared at 30[Formula: see text]C was amorphous, and it displayed the high specific capacitance as nearly four times as MnO2 at 80[Formula: see text]C. Due to MnO2 particles which would block carbon pores when its content was too high, the composite containing 30% of MnO2 exhibited the largest specific capacitance of 278.3[Formula: see text]F/g at 0.2[Formula: see text]A/g in K2SO4 electrolyte. The equivalent series resistance and charge transfer resistance of material were only 1.35[Formula: see text][Formula: see text] and 1.41[Formula: see text][Formula: see text], respectively. After 1000 cycles, the capacitance retention was still 91.6%. It indicated that chemical deposition was a facile, low cost and effective method to prepare MnO2/AC with good electrochemical performances.

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