Temperature Controlled Synthesis of Ce–MnO2 Nanostructure: Promising Electrode Material for Supercapacitor Applications

2020 ◽  
Vol 12 (4) ◽  
pp. 461-469 ◽  
Author(s):  
Rajesh Rajagopal ◽  
Kwang-Sun Ryu

The objective of this study was to prepare Ce–MnO2 nanostructure composite as an electrode material for supercapacitor application. Ce–MnO2 nanostructure composite was synthesized by facile hydrothermal method at different temperatures. Structural details of pure and Ce–MnO2 nanostructure composite were studied using powder X-ray diffraction technique. The formation of flower like structure and strong interaction with Ce and MnO2 were confirmed by field emission electron microscope technique. Their electrochemical performances were elucidated by using cyclic voltammetry, charge–discharge, and electrochemical impedance spectroscopy techniques. Nearly rectangular shaped cyclic voltagram was observed for synthesized Ce–MnO2 nanostructure composite electrode, indicating the existence of electric double layer capacitance nature. Ce–MnO2 (130) nanostructure composite exhibited high specific capacitance value of 147.25 F/g at applied current density of 1 A/g in 1 M Li2SO4 aqueous electrolyte. Furthermore, resistive and capacitive behaviors of these electrodes were studied from Nyquist and bode diagrams within frequency range of 10 mHz to 100 kHz.

2011 ◽  
Vol 399-401 ◽  
pp. 1451-1456 ◽  
Author(s):  
Gang Luo ◽  
Shi Chao Zhang ◽  
Hua Fang

A new two-step synthesis of composite electrode based on carbon nanotubes (CNTs) and cobalt oxide (Co3O4) by electrophoretic deposition of CNTs on Ni foam followed by electrodeposition of cobalt hydroxide on CNTs electrode and heat treatment to form Co3O4/CNTs composite electrode was developed. The structure and morphology of the electrodes were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Their electrochemical performances were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). Experimental results indicated that the nanocomposite electrodes exhibitd excellent pseudocapacitive behavior. In the potential range of 0.1- 0.45 V(vs SCE), the nanocomposite electrode showed a high specific capacitance of 867 F•g-1 in 6 M KOH electrolyte and a capacity retention of 90% after 1000 cycles at a current density of 1 A•g-1.


2022 ◽  
Author(s):  
Chong-Huan Wang ◽  
Da-Wei Zhang ◽  
Shude Liu ◽  
Yusuke Yamauchi ◽  
Fei-Bao Zhang ◽  
...  

Herein, we propose a solvent-assisted approach for preparing Ni-MOF microflowers with high specific capacitance and excellent rate capability as an electrode material for supercapacitors. Such high electrochemical performance is attributed...


2020 ◽  
Vol 20 (10) ◽  
pp. 6235-6244 ◽  
Author(s):  
A. Murugan ◽  
V. Siva ◽  
A. Shameem ◽  
S. Asath Bahadur

The Cu2ZnSnS4 (CZTS) thin films have been prepared at different deposition cycles, deposited on a glass substrate by successive ionic layer adsorption and reaction (SILAR) method followed by the annealing process at elevated temperature. The investigations on the films have been carried out to understand and confirm its structure, functional group present, crystalline morphology, optical and electrochemical behavior. The powder X-ray diffraction patterns recorded indicate that the deposited films are formed in the tetragonal structure. Other parameters like grain size, dislocation density, and microstrain are also calculated. The uniform surface of the films with spherical shaped morphology has been observed by Scanning Electron Microscopy, and the elemental compositions have been confirmed by EDAX. Electrochemical behavior such as cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge–discharge analysis have been carried out by electrochemical workstation. The modified electrode exhibits maximum specific capacitance value as 416 F/g for a pure sample. Optical studies have shown that the band gaps are estimated between 1.40 eV and 1.57 eV.


2018 ◽  
Vol 30 (8) ◽  
pp. 918-926 ◽  
Author(s):  
Rakhi Nangia ◽  
Neeraj K Shukla ◽  
Ambika Sharma

In this work, polymer blend films based on polyvinyl alcohol (PVA)/poly(ethylene glycol) (PEG) were prepared by solution casting technique. X-ray diffraction (XRD) analysis was performed to investigate the structural details of the polymer blend. XRD pattern confirms the polycrystalline nature of the films. Sandwich structures of the type Ag-PVA/PEG-Ag were formed to study the dielectric and conduction properties in the frequency range 300 Hz–3 MHz and at different temperatures varying from 298 K to 420 K. Experimental results show that both dielectric constant ( ε′) and dielectric loss ( ε″) values were strong functions of frequency and temperature. The AC conductivity ( σAC) was found to obey the power law Aωs and correlated barrier hopping as the conduction mechanism. The imaginary part of electric modulus shows peak shifting corresponding to relaxation mechanisms. Electric modulus study was also found to support the dielectric permittivity data.


2020 ◽  
Vol 13 (02) ◽  
pp. 2051005 ◽  
Author(s):  
Godlaveeti Sreenivasa Kumar ◽  
Somala Adinarayana Reddy ◽  
Hussen Maseed ◽  
Nagireddy Ramamanohar Reddy

In this work, we present the synthesis of a ternary CeO2–SnO2/rGO nanocomposite by using a facile one-step hydrothermal method. The as-synthesized composite was structural, chemical, morphological, elemental information studied by using different characterization techniques X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDAX) and transmission electron microscope (TEM). The CeO2–SnO2/rGO exhibited an excellent specific capacitance of 156[Formula: see text]F[Formula: see text][Formula: see text] at 0.5[Formula: see text]A/g in the presence of 3 M KOH solution. The synergic effect of CeO2, SnO2 and graphene composite coated on Ni foam endowed a high specific capacitance than their individual compounds. This work suggests that the novel ternary composite is a promising candidate for the high performance electrochemical energy storage and conversion systems.


Materials ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 2961 ◽  
Author(s):  
Aarti S. Bhatt ◽  
R. Ranjitha ◽  
M. S. Santosh ◽  
C. R. Ravikumar ◽  
S. C. Prashantha ◽  
...  

Nanostructured NiO and Li-ion doped NiO have been synthesized via a facile microwave technique and simulated using the first principle method. The effects of microwaves on the morphology of the nanostructures have been studied by Field Emission Spectroscopy. X-ray diffraction studies confirm the nanosize of the particles and favoured orientations along the (111), (200) and (220) planes revealing the cubic structure. The optical band gap decreases from 3.3 eV (pure NiO) to 3.17 eV (NiO doped with 1% Li). Further, computational simulations have been performed to understand the optical behaviour of the synthesized nanoparticles. The optical properties of the doped materials exhibit violet, blue and green emissions, as evaluated using photoluminescence (PL) spectroscopy. In the presence of Li-ions, NiO nanoparticles exhibit enhanced electrical capacities and better cyclability. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) results show that with 1% Li as dopant, there is a marked improvement in the reversibility and the conductance value of NiO. The results are encouraging as the synthesized nanoparticles stand a better chance of being used as an active material for electrochromic, electro-optic and supercapacitor applications.


MRS Advances ◽  
2016 ◽  
Vol 1 (45) ◽  
pp. 3089-3097 ◽  
Author(s):  
H. Adhikari ◽  
C. Ranaweera ◽  
R. Gupta ◽  
S. R. Mishra

ABSTRACTA facile hydrothermal method was used to synthesize molybdenum disulfide (MoS2) microspheres. The effect of hydrothermal reaction time on morphology and electrochemical properties of MoS2 microspheres was evaluated. X-ray diffraction showed presence of crystalline MoS2 structure, where content of crystalline phase was observed to increase with hydrothermal reaction time. Electrochemical properties of MoS2 were evaluated using cyclic voltammetry (CV) and galvanostatic charge-discharge in 3M KOH solution. Specific capacitance of nanostructured MoS2 was observed to be between 68 F/g and 346 F/g at different scan rates along with excellent cyclic stability. High power density (∼1200 W/kg) and energy density (∼5 Wh/kg) was observed for MoS2 sample synthesized for 24 hours of hydrothermal reaction time. Overall optimal electrocapactive performance was observed for sample prepared for 24 hours of reaction time. It is demonstrated that the obtained MoS2 microspheres with three-dimensional architecture has excellent electrochemical performances as electrode materials for supercapacitor applications.


2010 ◽  
Vol 152-153 ◽  
pp. 229-237
Author(s):  
Xian Liang Zhou ◽  
Min Zhu ◽  
Xiao Zhen Hua ◽  
Zhi Guo Ye ◽  
Qing Jun Chen

Various structure scales at the surface of SS400 hot rolled strip were fabricated by heat treatment processes involving different temperatures. A simulation about the effect of various temperatures on the oxide scale structure during the coiling process was carried out. The structure and corrosion behavior of different oxide scales formed at the surface of hot rolled strip were investigated in sodium bisulfite (NaHSO3) solution by scanning electron microscope (SEM), X-ray diffraction (XRD), polarization curves and electrochemical impedance spectroscopy (EIS). The scale prepared at 550 °C is mainly composed of one layer of Fe3O4 phase. The scales prepared at 600 °C and 700 °C consist of the outer thin Fe2O3 layer and the inner (Fe3O4+Fe particles) layer. The scale prepared at 650 °C is mainly composed of Fe3O4 phase as well as a spot of Fe2O3 phase. The thickness of scale prepared at 650°C is observed to be more homogeneous than that of other scales and the bonding between the scale and substrate is found to be very strong. The experimental results clearly reveal that the hot rolled strip with scale prepared at 650 °C exhibits the most excellent corrosion resisting property in 0.01 mol/L NaHSO3 solution.


2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Shuyuan Wang ◽  
Guangjie Shao

A number of carbide-derived carbon (CDC) samples were successfully synthesized by the electrolysis of SiC powder in molten CaCl2. The electrolysis was conducted at different temperatures (850, 900, and 950°C) for 48 h in argon at an applied constant voltage of 3.1 V. The structure of the resulting carbon is characterized by X-ray diffraction, Raman spectroscopy, and transmission electron microscope techniques. Cyclic voltammetry and galvanostatic charge/discharge measurements are applied to investigate electrochemical performances of the SiC-CDC material. It can be seen that the degree of order of the SiC-CDC increases monotonically along with elevation of reaction temperature, while the highest specific surface area 1137.74 m2/g together with a specific capacitance of 161.27 F/g at a current density 300 mA/g was achieved from sample synthesized at 900°C.


2018 ◽  
Vol 24 (8) ◽  
pp. 5587-5592
Author(s):  
S. C Bhise ◽  
D. V Awale ◽  
M. M Vadiyar ◽  
S. K Patil ◽  
B. N Kokare ◽  
...  

In the present work we report the controlled synthesis of NiO thin film with nano-leaves like morphology using reflux method. The synthesized NiO electrode is used as working electrode for supercapacitor application. The deposited NiO thin film was characterized using thermogravimetric (TGA) analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The supercapacitor behaviour of NiO was investigated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy using 3 M KOH electrolyte. The electrochemical results show specific capacitance of 513 F g−1 at 10 mV s−1 scan rate, power density (10.44 kW kg−1), energy density (14 Wh kg−1) and 85% capacitance retention over 5000 cycles. These remarkable results indicate the importance of the NiO nano-leaves electrode in energy storage device.


Sign in / Sign up

Export Citation Format

Share Document