Template-Free Electrochemical Synthesis of Well-Aligned Polypyrrole Nanofibers for Electrochemical Supercapacitors

2012 ◽  
Vol 512-515 ◽  
pp. 1776-1779
Author(s):  
Jing Li ◽  
Hua Qing Xie ◽  
Yang Li
Keyword(s):  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Electrochemical Technique ◽  
Diffusion Resistance ◽  
Carbon Electrode ◽  
Electrochemical Supercapacitors ◽  
Discharge Current Density ◽  
Template Free ◽  
Structure And Design ◽  
Charge Discharge

A new well-aligned nanofibers structure of polypyrrole (WAPPy) has been successfully grown on glassy carbon electrode by using a simple, reliable, and template-free electrochemical technique. The unique structure and design not only reduces the diffusion resistance of electrolytes in the electrode material but also enhances its electrochemical performance. Electrochemical supercapacitors based on WAPPy achieved a specific capacitance of 365 F g-1 with an applied charge/discharge current density of 1 A g-1 over a potential window of -0.5 to 0.5 V. For comparison, the granules PPy particles have been also electrochemical synthesized by using KCl as electrolyte (PPy-Cl). The specific capacitance of PPy-Cl electrode is 120 F g-1. The high specific capacitance and good stability of the WAPPy electrode has great potential in various applications such as energy storage.

Effects of Deposition Temperatures on the Nanoflakes Co(OH)2 Porous Films for Supercapacitors

2011 ◽  
Vol 694 ◽  
pp. 214-218
Author(s):  
Zhan Jun Yu ◽  
Bin Bin Wang ◽  
Rong Bao Liao ◽  
Yu Min Cui
Keyword(s):  
Specific Capacitance ◽  
Electrochemical Impedance ◽  
Electrochemical Techniques ◽  
High Specific Capacitance ◽  
Electrochemical Technique ◽  
Porous Films ◽  
Discharge Current Density ◽  
A Charge ◽  
Maximum Specific Capacitance ◽  
Charge Discharge

Nanoflakes Co(OH)2 porous films were successfully synthesized by a facile electrochemical technique. The morphology was characterized by field emission scanning electron microscopy (FESEM). Electrochemical techniques such as cyclic voltammetry (CV), galvanostaitc charge/discharge and electrochemical impedance spectroscopy were used to study the effects of deposition temperatures on the capacitance of the films. The results exhibited that the Co(OH)2 films single electrode had high specific capacitance in KOH electrolyte. A maximum specific capacitance of 2780 F/g could be achieved for the Co(OH)2 film deposited at 50°C in 2 M aqueous KOH with 0 to 0.4V potential at a charge-discharge current density of 4 mA/cm2. Therefore, the obtained nanoflakes Co(OH)2 porous films can be a potential application electrode material for supercapacitors.

MnO2 nanowires-decorated carbon fiber cloth as electrodes for aqueous asymmetric supercapacitor

2018 ◽  
Vol 11 (02) ◽  
pp. 1850034 ◽  
Author(s):  
Congcong Hong ◽  
Xing Wang ◽  
Houlin Yu ◽  
Huaping Wu ◽  
Jianshan Wang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Specific Capacitance ◽  
Current Density ◽  
Discharge Current ◽  
High Specific Capacitance ◽  
High Energy ◽  
Discharge Current Density ◽  
Carbon Fiber Cloth ◽  
A Charge ◽  
Charge Discharge

Manganese dioxide nanowires (MnO2 NWs) anchored on carbon fiber cloth (CFC) were fabricated through a simple hydrothermal reaction and used as integrated electrodes for supercapacitor. The morphology-dependent electrochemical performance of MnO2 NWs was confirmed, yielding good capacitance performance with a high specific capacitance of 3.88[Formula: see text][Formula: see text] at a charge–discharge current density of 5[Formula: see text][Formula: see text] and excellent stability of 91.5% capacitance retention after 3000 cycles. Moreover, the composite electrodes were used to fabricate supercapacitors, which showed a high specific capacitance of 194[Formula: see text][Formula: see text] at a charge–discharge current density of 2[Formula: see text][Formula: see text] and high energy density of 0.108[Formula: see text][Formula: see text] at power density of 2[Formula: see text][Formula: see text], foreboding its potential application for high-performance supercapacitor.

Solvothermal Synthesis of Nanostructured α-Ni(OH)2/ Mesoporous Carbon Composites for Supercapacitors

2011 ◽  
Vol 239-242 ◽  
pp. 1227-1230
Author(s):  
Zhan Jun Yu ◽  
Ying Dai ◽  
Wen Chen
Keyword(s):  
Specific Capacitance ◽  
Mesoporous Carbon ◽  
High Specific Capacitance ◽  
Soft Template ◽  
Carbon Composites ◽  
X Ray Diffraction ◽  
Discharge Current Density ◽  
A Charge ◽  
Discharge Method ◽  
Charge Discharge

Nanostructured α-Ni(OH)2/ mesoporous carbon composites were synthesized by a facile solvothermal method using sodium dodecyle sulfate as a soft template and urea as a hydrolysis-controlling agent. The obtained products were characterized by X-ray diffraction(XRD), and scanning electron microscopy(SEM). Electrochemical properties studies were carried out using cyclic voltammetry(CV) and galvanostaitc charge/discharge method. The results exhibited that the α-Ni(OH)2/ mesoporous carbon composites single electrode had high specific capacitance in KOH electrolyte. The maximum specific capacitance of the α-Ni(OH)2/ mesoporous carbon composites single electrode was up to 2191 F/g in 6 M KOH solution at a charge-discharge current density of 4 mA/cm2, when the mass percent of mesoporous carbon was 5%. It is suggested its potential application in the electrode material for supercapacitors.

Synthesis and Characterization of Nanoflakes β-Ni(OH)2 Microspheres for Supercapacitors

2011 ◽  
Vol 230-232 ◽  
pp. 306-309 ◽  
Author(s):  
Zhan Jun Yu ◽  
Ying Dai ◽  
Wen Chen
Keyword(s):  
Specific Capacitance ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
X Ray Diffraction ◽  
Discharge Current Density ◽  
X Ray ◽  
A Charge ◽  
Maximum Specific Capacitance ◽  
Charge Discharge

Nanoflakes β-Ni(OH)2microspheres were successfully synthesized by a facile hydrothermal. The microstructures and morphology were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrochemical properties studies were carried out using cyclic voltammetry (CV), galvanostaitc charge/discharge and electrochemical impedance spectroscopy methods, respectively. The results exhibited that the β-Ni(OH)2single electrode had high specific capacitance in KOH electrolyte. A maximum specific capacitance of 1929 F/g could be achieved in 6 M aqueous KOH with 0 to 0.4 V potential at a charge-discharge current density of 6 mA/cm2. Therefore, the obtained nanoflakes β-Ni(OH)2microspheres can be a potential application electrode material for supercapacitors.

scholarly journals Fabrication of Hierarchical NiMoO4/NiMoO4 Nanoflowers on Highly Conductive Flexible Nickel Foam Substrate as a Capacitive Electrode Material for Supercapacitors with Enhanced Electrochemical Performance

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 1143 ◽  
Author(s):  
Anil Yedluri ◽  
Tarugu Anitha ◽  
Hee-Je Kim
Keyword(s):  
Energy Density ◽  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Electrode Material ◽  
High Performance ◽  
Nickel Foam ◽  
High Specific Capacitance ◽  
High Energy ◽  
High Energy Density ◽  
Charge Discharge

Hierarchical NiMoO4/NiMoO4 nanoflowers were fabricated on highly conductive flexible nickel foam (NF) substrates using a facile hydrothermal method to achieve rapid charge-discharge ability, high energy density, long cycling lifespan, and higher flexibility for high-performance supercapacitor electrode materials. The synthesized composite electrode material, NF/NiMoO4/NiMoO4 with a nanoball-like NF/NiMoO4 structure on a NiMoO4 surface over a NF substrate, formed a three-dimensional interconnected porous network for high-performance electrodes. The novel NF/NiMoO4/NiMoO4 nanoflowers not only enhanced the large surface area and increased the electrochemical activity, but also provided an enhanced rapid ion diffusion path and reduced the charge transfer resistance of the entire electrode effectively. The NF/NiMoO4/NiMoO4 composite exhibited significantly improved supercapacitor performance in terms of a sustained cycling life, high specific capacitance, rapid charge-discharge capability, high energy density, and good rate capability. Electrochemical analysis of the NF/NiMoO4/NiMoO4 nanoflowers fabricated on the NF substrate revealed ultra-high electrochemical performance with a high specific capacitance of 2121 F g−1 at 12 mA g−1 in a 3 M KOH electrolyte and 98.7% capacitance retention after 3000 cycles at 14 mA g−1. This performance was superior to the NF/NiMoO4 nanoball electrode (1672 F g−1 at 12 mA g−1 and capacitance retention 93.4% cycles). Most importantly, the SC (NF/NiMoO4/NiMoO4) device displayed a maximum energy density of 47.13 W h kg−1, which was significantly higher than that of NF/NiMoO4 (37.1 W h kg−1). Overall, the NF/NiMoO4/NiMoO4 composite is a suitable material for supercapacitor applications.

A novel synthesis of ultra thin graphene sheets for energy storage applications using malonic acid as a reducing agent

2014 ◽  
Vol 2 (47) ◽  
pp. 20345-20357 ◽  
Author(s):  
Anil Kumar ◽  
Mahima Khandelwal
Keyword(s):  
Energy Storage ◽  
Potential Energy ◽  
Specific Capacitance ◽  
Malonic Acid ◽  
High Specific Capacitance ◽  
Reducing Agent ◽  
Graphene Sheets ◽  
Novel Synthesis ◽  
Energy Storage Applications ◽  
Charge Discharge

Novel ultrathin graphene sheets (0.41 ± 0.03 nm) with increased sp2 character, high specific capacitance and charge–discharge capability have been synthesized and demonstrated to have potential energy storage applications.

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.

Facile construction of ultrathin standing α-Ni(OH)2 nanosheets on halloysite nanotubes and their enhanced electrochemical capacitance

2014 ◽  
Vol 2 (29) ◽  
pp. 11299-11304 ◽  
Author(s):  
Jin Liang ◽  
Bitao Dong ◽  
Shujiang Ding ◽  
Cuiping Li ◽  
Ben Q. Li ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
Discharge Current ◽  
Halloysite Nanotubes ◽  
Cycling Stability ◽  
Hybrid Nanostructures ◽  
Electrochemical Capacitance ◽  
Discharge Current Density ◽  
High Charge ◽  
Charge Discharge

α-Ni(OH)2 nanosheets@HA hybrid nanostructures exhibit an excellent specific capacitance and cycling stability at a high charge–discharge current density.

MnOx/Ni(OH)2 Nanocomposite Materials for High-Performance Electrochemical Capacitor Application

2012 ◽  
Vol 20 ◽  
pp. 53-60 ◽  
Author(s):  
Zan Wang ◽  
Xin Wang ◽  
Yun Xiao Zhao ◽  
Cui Mei Zhao ◽  
Wei Tao Zheng
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
High Specific Capacitance ◽  
Discharge Process ◽  
Porous Network ◽  
X Ray ◽  
Capacitance Performance ◽  
Charge Discharge

Nanostructured MnOx/Ni (OH)2 composites have been electrodeposited on Ni foam for synthesis of a binder-free electrode for electrochemical capacitors with high specific capacitance and stable electrochemical properties. The microstructure, morphology and chemical composition were characterized by X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. Cyclic voltammetry and galvanostatic charge/discharge measurements were applied to investigate the electrochemical capacitance of the electrode active materials. The results indicated that MnOx acted as a template for growth of Ni (OH)2 with an inter-connected 3D porous network nanostructure. A maximum capacitance value of 2334 F/g at current density of 5 A/g in 1 M KOH electrolyte was achieved, much higher than that of pure Ni (OH)2 and MnOx (992 and 179 F/g, respectively). Moreover, in the charge/discharge process at even larger current density of 20 A/g, the electrode could maintain 82.8 % of the initial specific capacitance after 500 cycles, higher than that of pure Ni (OH)2 (only 46.6% remains). The enhanced capacitance performance was attributed to the synergic effect between the respective single oxides.

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