scholarly journals Electrochemically Reduced Titania Nanotube Synthesized from Glycerol-Based Electrolyte as Supercapacitor Electrode

Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2767 ◽  
Author(s):  
Muhammad Muhammad Muzakir ◽  
Zulkarnain Zainal ◽  
Hong Ngee Lim ◽  
Abdul Halim Abdullah ◽  
Noor Nazihah Bahrudin ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Reduction Process ◽  
High Specific Capacitance ◽  
Charge Transfer Resistance ◽  
Tube Diameter ◽  
Titania Nanotubes ◽  
Supercapacitor Electrode ◽  
Transfer Resistance ◽  
Self Organized ◽  
Electrons And Ions

In this paper the synthesis of self-organized Titania nanotubes (TNTs) by a facile potentiostatic anodization in a glycerol-based electrolyte is reported. The optimized TNTs were subsequently reduced through a cathodic reduction process to enhance its capacitive performance. FESEM and XRD were used to characterize the morphology and crystal structure of the synthesized samples. XPS analysis confirmed the reduction of Ti4+ to Ti3+ ions in the reduced Titania nanotubes (R-TNTs). The tube diameter and separation between the tubes were greatly influenced by the applied voltage. TNTs synthesized at voltage of 30 V for 60 min exhibited 86 nm and 1.1 µm of tube diameter and length, respectively and showed high specific capacitance of 0.33 mF cm−2 at current density of 0.02 mA cm−2. After reduction at 5 V for 30 s, the specific capacitance increased by about seven times (2.28 mF cm−2) at 0.5 mA cm−2 and recorded about 86% capacitance retention after 1000 continuous cycling at 0.2 mA cm−2, as compared to TNTs, retained about 61% at 0.01 mA cm−2. The charge transfer resistance drastically reduced from 6.2 Ω for TNTs to 0.55 Ω for R-TNTs, indicating an improvement in the transfer of electrons and ions across the electrode–electrolyte interface.

Facile Preparation of NiO/Ni Nanocomposite and its Electrochemical Capacitive Behaviors

2011 ◽  
Vol 306-307 ◽  
pp. 134-138 ◽  
Author(s):  
Wei Dong Yin ◽  
Gui Lian Li ◽  
Xian Ming Liu
Keyword(s):  
Specific Capacitance ◽  
Oxidation Process ◽  
Aqueous Electrolyte ◽  
High Specific Capacitance ◽  
Cycling Performance ◽  
Charge Transfer Resistance ◽  
Electrochemical Performances ◽  
Composite Electrodes ◽  
Galvanostatic Charge ◽  
Transfer Resistance

NiO/Ni nanocomposites were prepared by chemically reduction-oxidation process in tetra-ethylene glycol (TEG) solution. The structure and morphology of the samples were examined by XRD and SEM. The results indicated the composite consisted of NiO and Ni and exhibited spherical morphology with diameter of 50-200 nm. The electrochemical performances of composite electrodes used in electrochemical capacitors were studied. The electrochemical measurements were carried out using cyclic voltammetry, galvanostatic charge/discharge and impedance spectroscopy in 6M KOH aqueous electrolyte using three-electrode Swagelok systems. The results showed that the composite had a high specific capacitance and excellent capacitive behavior. The specific capacitance of the composite decreased to 192F/g after 500 cycles. Due to the existance of Ni, the charge transfer resistance is lower than 1Ω. It revealed that the composite exhibited good cycling performance.

scholarly journals Facilely Synthesized NiCo2O4/NiCo2O4 Nanofile Arrays Supported on Nickel Foam by a Hydrothermal Method and Their Excellent Performance for High-Rate Supercapacitance

Energies ◽  
2019 ◽  
Vol 12 (7) ◽  
pp. 1308 ◽  
Author(s):  
Anil Yedluri ◽  
Eswar Araveeti ◽  
Hee-Je Kim
Keyword(s):  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Nickel Foam ◽  
Rate Capability ◽  
Charge Transfer Resistance ◽  
High Rate ◽  
Transfer Resistance ◽  
Electrons And Ions ◽  
Binary Metal Oxides ◽  
Hydrothermal Approach

NiCo2O4 nanoleaf arrays (NCO NLAs) and NiCo2O4/NiCO2O4 nanofile arrays (NCO/NCO NFAs) material was fabricated on flexible nickel foam (NF) using a facile hydrothermal approach. The electrochemical performance, including the specific capacitance, charge/discharge cycles, and lifecycle of the material after the hydrothermal treatment, was assessed. The morphological and structural behaviors of the NF@NCO NLAs and NF@NCO/NCO NFAs electrodes were analyzed using a range of analysis techniques. The as-obtained nanocomposite of the NF@NCO/NCO NFAs material delivered outstanding electrochemical performance, including an ultrahigh specific capacitance (Cs) of 2312 F g−1 at a current density of 2 mA cm−2, along with excellent cycling stability (98.7% capacitance retention after 5000 cycles at 5 mA cm−2). These values were higher than those of NF@NCO NLAs (Cs of 1950 F g−1 and 96.3% retention). The enhanced specific capacitance was attributed to the large electrochemical surface area, which allows for higher electrical conductivity and rapid transport between the electrons and ions as well as a much lower charge-transfer resistance and superior rate capability. These results clearly show that a combination of two types of binary metal oxides could be favorable for improving electrochemical performance and is expected to play a major role in the future development of nanofile-like composites (NF@NCO/NCO NFAs) for supercapacitor applications.

Preparation and electrochemical characterization of PANI/MnCo2O4 nanocomposite as supercapacitor electrode material

2018 ◽  
Vol 96 (5) ◽  
pp. 477-483 ◽  
Author(s):  
Saeid Panahi ◽  
Moosa Es’haghi
Keyword(s):  
Specific Capacitance ◽  
Surface Characterization ◽  
Electrochemical Impedance ◽  
Rate Capability ◽  
Cycling Performance ◽  
Charge Transfer Resistance ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Transfer Resistance

In this work, PANI/MnCo2O4 nanocomposite was prepared via in-situ chemical polymerization method. Materials synthesized were characterized by FTIR spectroscopy, X-ray diffraction, and scanning electron spectroscopy. In addition, surface characterization of samples such as specific surface area, pore volume, and pore size distribution was studied. Supercapacitor capability of materials was investigated in 1 mol L–1 Na2SO4 solution using cyclic voltammetry in different potential scan rates and electrochemical impedance spectroscopy (EIS). The specific capacitance of materials was calculated, and it was observed that the specific capacitance of PANI/MnCo2O4 nanocomposite was 185 F g−1, much larger than PANI. Moreover, the prepared nanocomposite exhibited better rate capability in scan rate of 100 mV s−1 with respect to PANI. The EIS experiments revealed that the nanocomposite has lower charge transfer resistance compared with pure PANI. Subsequently, it was shown that the nanocomposite cycling performance was superior to the PANI cycling performance.

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.

RGO/KMn8O16 composite as supercapacitor electrode with high specific capacitance

2016 ◽  
Vol 42 (4) ◽  
pp. 5195-5202 ◽  
Author(s):  
Hongtao Guan ◽  
Wenhui Dang ◽  
Gang Chen ◽  
Chengjun Dong ◽  
Yude Wang
Keyword(s):  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Supercapacitor Electrode

A Facile Synthesis of NiFe2O4 with High Specific Capacitance as Supercapacitor Electrode Material

2018 ◽  
Vol 281 ◽  
pp. 854-858
Author(s):  
Xi Cheng Gao ◽  
Jian Qiang Bi ◽  
Wei Li Wang ◽  
Guo Xun Sun ◽  
Xu Xia Hao ◽  
...  
Keyword(s):  
Particle Size ◽  
Specific Capacitance ◽  
Electrochemical Property ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Constant Current ◽  
X Ray Diffraction ◽  
Supercapacitor Electrode ◽  
Constant Current Charge ◽  
Supercapacitor Electrode Materials

NiFe2O4 powders were synthesized by a facile hydrothermal method at 180°C followed by a thermal treatment at 300°C. The phase composition and morphology were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results showed that the NiFe2O4 powders were well-crystallized, and they possessed a particle size in the range of 50-100 nm. The electrochemical property was characterized via cyclic voltammetry (CV) and constant current charge-discharge method. Encouragingly, the NiFe2O4 powders had an excellent electrochemical property, whose specific capacitance reached 266.84 F/g at the electric current density of 1 A/g due to the small particle size. Compared with other Fe-based metal compound oxides, NiFe2O4 has a better electrochemical performance, which can be widely used in the supercapacitor electrode materials.

Hierarchical Dendritic Polypyrrole with High Specific Capacitance for High-performance Supercapacitor Electrode Materials

2017 ◽  
Vol 20 (4) ◽  
pp. 197-204
Author(s):  
Weiliang Chen ◽  
Shuhua Pang ◽  
Zheng Liu ◽  
Zhewei Yang ◽  
Xin Fan ◽  
...  
Keyword(s):  
Specific Capacitance ◽  
Current Density ◽  
High Performance ◽  
Electrode Materials ◽  
High Specific Capacitance ◽  
Chemical Oxidation ◽  
Channel Structure ◽  
Supercapacitor Electrode ◽  
Infrared Spectrometer ◽  
A Current

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.

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.

Triethanolamine (TEA) Aqueous Solution as an Electrolyte Promoter in CO2 Photoelectro-Conversion under Simulated Solar Irradiation Assisted by Cu-Doped Graphene-Titania Catalyst

2015 ◽  
Vol 1109 ◽  
pp. 448-450 ◽  
Author(s):  
Md. Rakibul Hasan ◽  
Sharifah Bee binti O. A. Abdul Hamid ◽  
Wan Jeffrey Basirun
Keyword(s):  
Aqueous Solution ◽  
Sol Gel ◽  
Reduction Process ◽  
Charge Transfer Resistance ◽  
Vital Role ◽  
Solar Irradiation ◽  
Secondary Amines ◽  
Transfer Resistance ◽  
Doped Graphene ◽  
Simulated Solar Irradiation

Copper doped graphene-TiO2 nanocomposite were prepared via sol-gel process and embedded onto ITO coated glass films using electrophoretic deposition technique. The catalyst films were used for photoelectrocatalysis (PEC) of CO2 induced under simulated solar irradiation. Triethanolamine (TEA) aqueous solution was used as an electrolyte in this experiment. CO2 capture in the electrolyte solution plays vital role in the PEC process and in this case, the effect of TEA was investigated. Although the absorption rate of CO2 is lower in TEA solution than primary or secondary amines, CO2 loading was found higher in the solution. Less reactivity of TEA towards CO2 was also observed. The impedance results showed that, increased concentration of TEA in aqueous solution helps to reduce charge transfer resistance and thus facilitates CO2 reduction process.

Electrochemical Decomposition of Poly(Vinylidene Fluoride) Binder for a Graphite Negative Electrode in Lithium-Ion Batteries

2017 ◽  
Vol 893 ◽  
pp. 127-131 ◽  
Author(s):  
Min Ji Kim ◽  
Chang Hee Lee ◽  
Mun Hui Jo ◽  
Soon Ki Jeong
Keyword(s):  
Lithium Ion Batteries ◽  
Vinylidene Fluoride ◽  
Electrochemical Impedance ◽  
Negative Electrode ◽  
Reduction Process ◽  
Lithium Ion ◽  
Charge Transfer Resistance ◽  
Transfer Resistance ◽  
Electrode Resistance ◽  
Poly Vinylidene Fluoride

To clarify the electrochemical decomposition of poly (vinylidene fluoride) (PVdF) used as a binder for lithium-ion batteries while simultaneously verifying the correlation between electrode resistance and the PVdF content in graphite negative electrodes, in this study, we applied lithium bis (trifluoromethanesulfonyl) imide, which suppresses graphite exfoliation, as a salt. As a result, the electrochemical decomposition of PVdF was observed at a higher potential than that at which the electrolyte was decomposed during the reduction process. Additionally, this study demonstrated (through electrochemical impedance spectroscopy analysis) that electrode resistances such as solid electrolyte interface and charge transfer resistance proportionally increased with the PVdF content.

Sign in / Sign up

Export Citation Format

Share Document