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.

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.

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.

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.

scholarly journals A Promising Polymer Blend Electrolytes Based on Chitosan: Methyl Cellulose for EDLC Application with High Specific Capacitance and Energy Density

Molecules ◽  
2019 ◽  
Vol 24 (13) ◽  
pp. 2503 ◽  
Author(s):  
Shujahadeen B. Aziz ◽  
M. H. Hamsan ◽  
Ranjdar M. Abdullah ◽  
M. F. Z. Kadir
Keyword(s):  
Energy Density ◽  
Specific Capacitance ◽  
Double Layer ◽  
Polymer Blend ◽  
Electrochemical Techniques ◽  
High Specific Capacitance ◽  
Transference Number ◽  
Constant Current ◽  
Equivalent Series Resistance ◽  
Charge Discharge

In the present work, promising proton conducting solid polymer blend electrolytes (SPBEs) composed of chitosan (CS) and methylcellulose (MC) were prepared for electrochemical double-layer capacitor (EDLC) application with a high specific capacitance and energy density. The change in intensity and the broad nature of the XRD pattern of doped samples compared to pure CS:MC system evidencedthe amorphous character of the electrolyte samples. The morphology of the samples in FESEM images supported the amorphous behavior of the solid electrolyte films. The results of impedance and Bode plotindicate that the bulk resistance decreasedwith increasing salt concentration. The highest DC conductivity was found to be 2.81 × 10−3 S/cm. The electrical equivalent circuit (EEC) model was conducted for selected samples to explain the complete picture of the electrical properties.The performance of EDLC cells was examined at room temperature by electrochemical techniques, such as impedance spectroscopy, cyclic voltammetry (CV) and constant current charge–discharge techniques. It was found that the studied samples exhibit a very good performance as electrolyte for EDLC applications. Ions were found to be the dominant charge carriers in the polymer electrolyte. The ion transference number (tion) was found to be 0.84 while 0.16 for electron transference number (tel). Through investigation of linear sweep voltammetry (LSV), the CS:MC:NH4SCN system was found to be electrochemically stable up to 1.8 V. The CV plot revealed no redox peak, indicating the occurrence of charge double-layer at the surface of activated carbon electrodes. Specific capacitance (Cspe) for the fabricated EDLC was calculated using CV plot and charge–discharge analyses. It was found to be 66.3 F g−1 and 69.9 F g−1 (at thefirst cycle), respectively. Equivalent series resistance (Resr) of the EDLC was also identified, ranging from 50.0 to 150.0 Ω. Finally, energy density (Ed) was stabilized to anaverage of 8.63 Wh kg−1 from the 10th cycle to the 100th cycle. The first cycle obtained power density (Pd) of 1666.6 W kg−1 and then itdropped to 747.0 W kg−1 at the 50th cycle and continued to drop to 555.5 W kg−1 as the EDLC completed 100 cycles.

Preparation and Performance of High Activation Carbon Microbeads for Application of Supercapacitors

2011 ◽  
Vol 15 (1) ◽  
pp. 15-20 ◽  
Author(s):  
Li Bai ◽  
Xingyan Wang ◽  
Xianyou Wang ◽  
Xiaoyan Zhang ◽  
Wanmei Long ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Electrochemical Characteristics ◽  
High Activation ◽  
Hydrothermal Route ◽  
Discharge Current Density ◽  
Scanning Rate ◽  
Infrared Spectrometer ◽  
And Performance ◽  
A Charge ◽  
Charge Discharge

Carbon microbeads (CMB) were successfully prepared by glucose hydrothermal route in a stainless steel autoclave. The CMB was treated in concentrated nitric acid in order to gain the highly activated carbon microbeads (ACMB). The structure and surface morphology of as-prepared ACMB were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR), respectively. The electrochemical characteristics and capacitive behaviors of the ACMB were studied by cyclic voltammetry, current charge/discharge and cycle life measurements. The results show that the ACMB electrode has good electrochemical performance and the specific capacitance of ACMB is 291.9 F g-1 at a scanning rate of 1 mV s-1. Meanwhile, the specific capacitance of the button supercapacitor was as high as 75 F g-1 at a charge/discharge current density of 0.5 A g-1 and the loss of specific capacitance was nearly neglectable after 5000 cycles.

Electrochemical Capacitance Properties of Electrode Based on Polyaniline Coated Graphite Nanoplatelets/Polystyrene Composite Film

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Tanveer ul Haq Zia ◽  
Ahmad Nawaz Khan ◽  
Behisht Ara ◽  
Kashif Gul
Keyword(s):  
Specific Capacitance ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Specific Power ◽  
Graphite Nanoplatelets ◽  
Polystyrene Matrix ◽  
A Current ◽  
In Situ Emulsion Polymerization ◽  
Charge Discharge

Abstract The electrochemical behavior of the electrode material based on composites of polyaniline (PANI), graphite nanoplatelets (GnP), and polystyrene (PS) matrix was evaluated by applying cyclic voltammetry (CV), galvanostatic charge–discharge (GCD), and electrochemical impedance spectroscopy (EIS), for its application in electrochemical supercapacitor which is an advanced energy storing device. Composites were prepared by coating polyaniline on graphite nanoplatelets (PANI/GnP) via in situ emulsion polymerization, exhibiting specific surface area of 178.75 m2/g as compared with 72.1 m2/g of pristine GnP. The PANI/GnP was then embedded in polystyrene matrix (PANI/GnP/PS), which showed improved electrical conductivity due to an interconnected mesh of PANI/GnP as confirmed by scanning electron microscopy (SEM) morphological analysis. The formation of porous conductive network in PANI/GnP/PS with conductivity value of 8.6 × 10−3 S/cm resulted in high specific capacitance of 411.3 F/g measured at a current density of 0.5 A/g which corresponded to specific energy of 47.94 Wh/kg and specific power of 281.94 W/kg, as well as the decrease in specific capacitance was 32% even after 1600 charge–discharge cycles showing good rate performance which renders it an ideal material for electrodes in supercapacitors.

Synthesis and Characterization of Ni(OH)2/Multiwalled Carbon Nanotubes Nanocomposites for Electrochemical Capacitors

2011 ◽  
Vol 239-242 ◽  
pp. 2968-2971 ◽  
Author(s):  
Zhan Jun Yu ◽  
Ying Dai ◽  
Wen Chen
Keyword(s):  
Carbon Nanotubes ◽  
Multiwalled Carbon Nanotubes ◽  
Active Sites ◽  
Electrochemical Impedance ◽  
Electrochemical Capacitors ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Discharge Current Density ◽  
A Charge ◽  
Charge Discharge

Ni(OH)2/multiwalled carbon nanotubes (Ni(OH)2/MWNTs) nanocomposites were synthesized by hydrothermal method. The microstructures of such nanocomposites 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 method. The presence of MWNTs network in the Ni(OH)2 significantly improved the electrical conductivity of the host Ni(OH)2 by the fromation of conducting network of MWNT and the active sites for the redox rection of the metal hydroxide. The specific capacitance of the new composites was significantly improved (MWNTs of 20 wt.%, 2144 F/g) compared to Ni(OH)2 (MWNTs of 0 wt.%, 1772 F/g) in 6 M KOH solution at a charge-discharge current density of 4 mA/cm2. Therefore, the Ni(OH)2/MWNTs nanocomposites can be a potential application electrode material for electrochemical capacitors.

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.

Sign in / Sign up

Export Citation Format

Share Document