Hierarchical NiMn Double Layered/Graphene with Excellent Energy Density for Highly Capacitive Supercapacitors

Abstract In the present article, highly capacitive NiMn-LDHs/GO composite of electrode material has been the synthesized for supercapacitor energy storage. Various analytical techniques (particularly X-ray diffraction (XRD), Raman spectroscopy, high resolution transmission electron microscopy (HRTEM), and scanning electron microscope (SEM)) have been employed to characterize the as-synthesized NiMn-LDHs/GO. The Microscopic images obtained using HRTEM analysis clearly reveal the formation of lattice fringe pattern (lattice spacing as ~ 0.22 nm) for GO, whereas SEM images shows highly porous nature. The super-capacitive performance of the as-synthesized electrode material have been accessed through an electrochemical work station comprising of a 3-electrode system. The working electrode made up of NiMn-LDHs/GO (Active material) on Ni foil (working electrode) with the help of PVDF (binder), has shown specific capacitance of 1964 F g−1 at current density of 1 A g−1 with Galvanostatic charging/discharging (GCD) technique. It has also shown remarkable cyclic stability with a capacitance retention of 98% after 2000 cycles. The high-power density (401 W/kg) and energy density (17.78 Wh/kg) signify the high-level electrochemical supercapacitor behaviour in charge storage applications.

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Improved electrochemical behavior of metal oxides-based nanocomposites for supercapacitor

Functional Materials Letters ◽

10.1142/s1793604719500644 ◽

2019 ◽

Vol 12 (05) ◽

pp. 1950064 ◽

Cited By ~ 8

Author(s):

P. Anandhi ◽

V. Jawahar Senthil Kumar ◽

S. Harikrishnan

Keyword(s):

Electron Microscopy ◽

Electrode Material ◽

Sol Gel ◽

Active Material ◽

Galvanostatic Charge ◽

Electrochemical Behaviors ◽

Transmission Electron ◽

Gel Technique ◽

Promising Electrode Material ◽

Charge Discharge

This paper investigates the synthesis and enhanced electrochemical behaviors of ZnO and NiO/ZnO nanocomposites for electrode material of supercapacitors. ZnO and NiO/ZnO nanocomposites were produced via sol–gel technique. Transmission electron microscopy (TEM) and field emission scanning electron microscopy (FESEM) were used to determine the size and structure of as-synthesized nanomaterials, respectively. The capacitive behavior and charge–discharge characteristics of the electrode using ZnO and NiO/ZnO nanocomposites (as active material) were individually probed with the help of cyclic voltammetry (CV) and galvanostatic charge-discharge tests, respectively. The specific capacitance of nanocomposites-based electrode calculated from galvanostatic charge-discharge tests was 469[Formula: see text]F [Formula: see text] at the scan rate of 1[Formula: see text]mA [Formula: see text] in 1M Na2SO4 electrolyte. The power density and energy density at the current density of 1[Formula: see text]mA [Formula: see text] were determined as 1458.33[Formula: see text]W [Formula: see text] and 91.14[Formula: see text]Wh[Formula: see text][Formula: see text], respectively. Hence, NiO/ZnO nanocomposites could be reckoned to be a promising electrode material for supercapacitor while comparing to ZnO-based electrode material.

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Hydrothermal Prepared α-MnO2 Nanowire and its Supercapacitor Electrochemical Performances

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.953-954.1040 ◽

2014 ◽

Vol 953-954 ◽

pp. 1040-1044

Author(s):

Yang Li ◽

Jing Li ◽

Hua Qing Xie

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Electrode Material ◽

Scan Electron Microscopy ◽

Active Material ◽

Electrochemical Performances ◽

X Ray Diffraction ◽

X Ray ◽

Transmission Electron ◽

Potential Alternative

α-MnO2nanowire was prepared by hydrothermal method. The structure of as-prepared manganese oxide demonstrated tetragonal crystalline in X-ray diffraction pattern. Scan electron microscopy (SEM) and Transmission electron microscopy (TEM) revealed the nanowire morphology of as-prepared α-MnO2. The band gap of α-MnO2was estimated at about 2.06 eV via UV-vis spectrum. As the electrode active material for supercapacitor, the electrochemical specific capacitance of α-MnO2nanowire achieved 156.5 F/g, which possessed typical capacitive behaviors and good cycling stabilities. Based on the preferable electrochemical performances, as-synthesized α-MnO2nanowire may be a potential alternative as electrode material for supercapacitor.

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STUDY OF COPPER FERRITE NANOWIRE FORMATION IN PRESENCE OF CARBON NANOTUBES AND INFLUENCE OF FLUORINATION ON HIGH PERFORMANCE SUPERCAPACITOR ENERGY STORAGE APPLICATION

Functional Materials Letters ◽

10.1142/s1793604712500464 ◽

2012 ◽

Vol 05 (04) ◽

pp. 1250046 ◽

Cited By ~ 13

Author(s):

SOUMEN GIRI ◽

DEBASIS GHOSH ◽

ALEXANDER P. KHARITONOV ◽

CHAPAL KUMAR DAS

Keyword(s):

Electron Microscopy ◽

Carbon Nanotubes ◽

Energy Storage ◽

High Performance ◽

Electrode System ◽

Modern World ◽

Storage Device ◽

Copper Ferrite ◽

Transmission Electron ◽

Supercapacitor Energy Storage

Supercapacitors are highly attractive energy storage device of the modern world. It can supply peak pulse power and high cycle stability to an electrochemical system. Here, we have explored the formation of copper ferrite ( CuFe2O4 ) nanowire formation in presence of carbon nanotubes (CNTs) and enhancement of electrochemical performance on fluorination. All the electrochemical characterization was studied by three electrode system. Fourier transform infrared spectroscopy (FT-IR) was performed to test the functionality present in the composite. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) study had been carried out to observe the change in surface and bulk morphology of the composites which showed that CuFe2O4 nanowires are attached with CNTs or fluorinated CNTs. This fluorinated nanocomposite shows the highest specific capacitance of 267 F/g.

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The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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Comparison of Ion-Milling Techniques For Cross-Sectional TEM of Semiconductors

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100117807 ◽

1985 ◽

Vol 43 ◽

pp. 166-167

Author(s):

Julia T. Luck ◽

C. W. Boggs ◽

S. J. Pennycook

Keyword(s):

Analytical Techniques ◽

Sample Surface ◽

Ion Milling ◽

Cross Sectional ◽

Reliable Technique ◽

Near Surface ◽

Transmission Electron ◽

Thin Region ◽

Transient Thermal

The use of cross-sectional Transmission Electron Microscopy (TEM) has become invaluable for the characterization of the near-surface regions of semiconductors following ion-implantation and/or transient thermal processing. A fast and reliable technique is required which produces a large thin region while preserving the original sample surface. New analytical techniques, particularly the direct imaging of dopant distributions, also require good thickness uniformity. Two methods of ion milling are commonly used, and are compared below. The older method involves milling with a single gun from each side in turn, whereas a newer method uses two guns to mill from both sides simultaneously.

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High Resolution Transmission Electron Microscopy of an automobile catalytic converter

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100174345 ◽

1990 ◽

Vol 48 (4) ◽

pp. 242-243

Author(s):

Jan-Olle Malm ◽

Jan-Olov Bovin

Keyword(s):

Electron Microscopy ◽

High Resolution ◽

Catalytic Converter ◽

Active Material ◽

Image Intensifier ◽

High Resolution Electron Microscopy ◽

Detailed Knowledge ◽

Transmission Electron ◽

Resolution Electron ◽

Atomic Surface

Understanding of catalytic processes requires detailed knowledge of the catalyst. As heterogeneous catalysis is a surface phenomena the understanding of the atomic surface structure of both the active material and the support material is of utmost importance. This work is a high resolution electron microscopy (HREM) study of different phases found in a used automobile catalytic converter.The high resolution micrographs were obtained with a JEM-4000EX working with a structural resolution better than 0.17 nm and equipped with a Gatan 622 TV-camera with an image intensifier. Some work (e.g. EDS-analysis and diffraction) was done with a JEM-2000FX equipped with a Link AN10000 EDX spectrometer. The catalytic converter in this study has been used under normal driving conditions for several years and has also been poisoned by using leaded fuel. To prepare the sample, parts of the monolith were crushed, dispersed in methanol and a drop of the dispersion was placed on the holey carbon grid.

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Investigation of Polyoxometalate-(Poly)pyrrole Heterogeneous Nanostructures as Cathodes for Rechargeable Magnesium-Ion Batteries

10.26434/chemrxiv.6716012 ◽

2018 ◽

Author(s):

Hakeem K. Henry ◽

Sang Bok Lee

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Photoelectron Spectroscopy ◽

Active Material ◽

Conductive Polymer ◽

Current Collector ◽

Constant Current ◽

Anodized Aluminum ◽

Transmission Electron ◽

Pyrrole Monomer

The PMo12-PPy heterogeneous cathode was synthesized electrochemically. In doing so, the PMo12 redox-active material was impregnated throughout the conductive polymer matrix of the poly(pyrrole) nanowires. All chemicals and reagents used were purchased from Sigma-Aldrich. Anodized aluminum oxide (AAO) purchased from Whatman served as the porous hard template for nanowire deposition. A thin layer of gold of approximately 200nm was sputtered onto the disordered side of the AAO membrane to serve as the current collector. Copper tape was connected to the sputtered gold for contact and the device was sealed in parafilm with heat with an exposed area of 0.32 cm2 to serve as the electroactive area for deposition. All electrochemical synthesis and experiments were conducted using a Bio-Logic MPG2 potentiostat. The deposition was carried out using a 3-electrode beaker cell setup with a solution of acetonitrile containing 5mM and 14mM of the phosphomolybdic acid and pyrrole monomer, respectively. The synthesis was achieved using chronoamperometry to apply a constant voltage of 0.8V vs. Ag/AgCl (BASi) to oxidatively polymerize the pyrrole monomer to poly(pyrrole). To prevent the POM from chemically polymerizing the pyrrole, an injection method was used in which the pyrrole monomer was added to the POM solution only after the deposition voltage had already been applied. The deposition was well controlled by limiting the amount of charge transferred to 300mC. Following deposition, the AAO template was removed by soaking in 3M sodium hydroxide (NaOH) for 20 minutes and rinsed several times with water. After synthesis, all cathodes underwent electrochemical testing to determine their performance using cyclic voltammetry and constant current charge-discharge cycling in 0.1 M Mg(ClO4)2/PC electrolyte. The cathodes were further characterized using scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), and x-ray photoelectron spectroscopy (XPS).

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Antitumor Potential of Green Synthesized ZnONPs Using Root Extract of Withania somnifera against Human Breast Cancer Cell Line

Separations ◽

10.3390/separations8010008 ◽

2021 ◽

Vol 8 (1) ◽

pp. 8

Author(s):

Kollur Shiva Prasad ◽

Shashanka K Prasad ◽

Ravindra Veerapur ◽

Ghada Lamraoui ◽

Ashwini Prasad ◽

...

Keyword(s):

Breast Cancer ◽

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Cell Line ◽

Withania Somnifera ◽

Root Extract ◽

Dependent Manner ◽

Sem Images ◽

Xrd Pattern ◽

Transmission Electron

Herein we report the synthesis of zinc oxide nanoparticles (ZnONPs) using Withania somnifera root extract (WSE) as an effective chelating agent. The microscopic techniques viz., X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) were employed to analyze the as-obtained ZnONPs. The crystalline planes observed from the XRD pattern agrees with the hexagonal wurtzite structure of the as-prepared ZnONPs. The aggregations and agglomerations observed in the SEM images indicated that the size of the as-prepared ZnONPs was between 30 and 43 nm. The interplanar distance between the lattice fringes observed in the HRTEM image was found to be 0.253 nm, which is in good agreement with the (100) plane obtained in the XRD pattern. Furthermore, the anti-breast cancer cytotoxic evaluation was carried out using the MCF-7 cell line, and the results showed significant cytotoxic effects in a dose-dependent manner.

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Designing high energy density flow batteries by tuning active-material thermodynamics

RSC Advances ◽

10.1039/d0ra10913d ◽

2021 ◽

Vol 11 (10) ◽

pp. 5432-5443

Author(s):

Shyam K. Pahari ◽

Tugba Ceren Gokoglan ◽

Benjoe Rey B. Visayas ◽

Jennifer Woehl ◽

James A. Golen ◽

...

Keyword(s):

Renewable Energy ◽

Energy Storage ◽

Energy Density ◽

Fossil Fuels ◽

Active Material ◽

High Energy ◽

Theoretical Framework ◽

High Energy Density ◽

Density Flow ◽

The Cost

With the cost of renewable energy near parity with fossil fuels, energy storage is paramount. We report a breakthrough on a bioinspired NRFB active-material, with greatly improved solubility, and place it in a predictive theoretical framework.

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In Situ Fabrication of Activated Carbon from a Bio-Waste Desmostachya bipinnata for the Improved Supercapacitor Performance

Nanoscale Research Letters ◽

10.1186/s11671-021-03545-8 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Gopal Krishna Gupta ◽

Pinky Sagar ◽

Sumit Kumar Pandey ◽

Monika Srivastava ◽

A. K. Singh ◽

...

Keyword(s):

Activated Carbon ◽

Energy Density ◽

Power Density ◽

Supercapacitor Electrode ◽

In Situ Fabrication ◽

Transmission Electron ◽

Good Energy ◽

Supercapacitor Performance ◽

Operating Potential

AbstractHerein, we demonstrate the fabrication of highly capacitive activated carbon (AC) using a bio-waste Kusha grass (Desmostachya bipinnata), by employing a chemical process followed by activation through KOH. The as-synthesized few-layered activated carbon has been confirmed through X-ray powder diffraction, transmission electron microscopy, and Raman spectroscopy techniques. The chemical environment of the as-prepared sample has been accessed through FTIR and UV–visible spectroscopy. The surface area and porosity of the as-synthesized material have been accessed through the Brunauer–Emmett–Teller method. All the electrochemical measurements have been performed through cyclic voltammetry and galvanometric charging/discharging (GCD) method, but primarily, we focus on GCD due to the accuracy of the technique. Moreover, the as-synthesized AC material shows a maximum specific capacitance as 218 F g−1 in the potential window ranging from − 0.35 to + 0.45 V. Also, the AC exhibits an excellent energy density of ~ 19.3 Wh kg−1 and power density of ~ 277.92 W kg−1, respectively, in the same operating potential window. It has also shown very good capacitance retention capability even after 5000th cycles. The fabricated supercapacitor shows a good energy density and power density, respectively, and good retention in capacitance at remarkably higher charging/discharging rates with excellent cycling stability. Henceforth, bio-waste Kusha grass-derived activated carbon (DP-AC) shows good promise and can be applied in supercapacitor applications due to its outstanding electrochemical properties. Herein, we envision that our results illustrate a simple and innovative approach to synthesize a bio-waste Kusha grass-derived activated carbon (DP-AC) as an emerging supercapacitor electrode material and widen its practical application in electrochemical energy storage fields.

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