9 results on '"Gupta, Meenal"'
Search Results
2. Experimental Investigations on Highly Conducting Solid Bio‐Polymer Electrolytes Based on Latex of Calotropis gigantea Plant.
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Taneja, Neha, Bocchetta, Patrizia, Kumar, Ashwani, Gupta, Pallavi, Gupta, Meenal, Singh, Pushpa, Beniwal, Bharti, Agrawal, Namrata, and Kumar, Yogesh
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POLYELECTROLYTES ,SOLID electrolytes ,CONDUCTING polymer films ,LATEX ,CALOTROPIS ,IONIC conductivity - Abstract
The study has prepared highly conducting polymer electrolyte films using solution cast technique with poly(vinylidene fluoride‐co‐hexafluoropropylene) PVDF‐HFP, mixture of ethylene carbonate (EC), and propylene carbonate (PC) as plasticizer and latex of Calotropis gigantea (CGL) as an ionic source. In this study, four films are prepared using PVDF‐HFP:CGL in ratio 1:1 with the increasing concentration of EC+PC as 1, 2, 3, and 4 M named as 1:1:1, 1:1:2, 1:1:3, 1:1:4. The prepared polymer electrolyte is examined by polarized optical microscopy (POM), elemental dispersive X‐ray technique (EDX), and complex impedance spectroscopy. EDX and POM are studied for the surface morphology of all prepared samples and to investigate the porous nature of films. The enhancement in ionic conductivity occurs due to CGL and increasing amount of EC‐PC. Conductivity of highest composition (1:1:4) polymer electrolyte film is found to be ≈10−3 S cm−1. The optimized polymer electrolyte film is considered as a promising candidate for application in supercapacitors. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Green-Synthesized Graphene for Supercapacitors--Modern Perspectives.
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Kausar, Ayesha, Ahmad, Ishaq, Zhao, Tingkai, Eisa, M. H., Aldaghri, O., Gupta, Meenal, and Bocchetta, Patrizia
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GRAPHENE ,SUPERCAPACITOR electrodes ,SUPERCAPACITORS ,CONJUGATED polymers ,ENERGY storage ,NANOCOMPOSITE materials ,ELECTRIC capacity - Abstract
Graphene is a unique nanocarbon nanostructure, which has been frequently used to form nanocomposites. Green-synthesized graphene has been focused due to environmentally friendly requirements in recent technological sectors. A very important application of green-synthesized graphene-based nanocomposite has been observed in energy storage devices. This state-of-the-art review highlights design, features, and advanced functions of polymer/green-synthesized graphene nanocomposites and their utility in supercapacitor components. Green graphene-derived nanocomposites brought about numerous revolutions in high-performance supercapacitors. The structural diversity of conjugated polymer and green graphene-based nanocomposites has facilitated the charge transportation/storage capacity, specific capacitance, capacitance retention, cyclability, and durability of supercapacitor electrodes. Moreover, the green method, graphene functionality, dispersion, and matrix--nanofiller interactions have affected supercapacitance properties and performance. Future research on innovative polymer and green graphene-derived nanocomposites may overcome design/performance-related challenging factors for technical usages. [ABSTRACT FROM AUTHOR]
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- 2023
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4. Physical properties of heteroatom doped graphene monolayers in relation to supercapacitive performance
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Bharti, Karayel, Arzu, Gupta, Meenal, Ahmad, Gulzar, Kumar, Yogesh, Sharma, Shatendra, and [Belirlenecek]
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Supercapacitor ,Quantum capacitance ,Graphene ,Band Structure ,Density of States - Abstract
Electrodes fabricated using graphene are quite promising for electric double layer capacitors. However graphene has the limitations of low 'Quantum Capacitance (QC)' near fermi level due to the presence of Dirac point that can be modified by doping graphene with suitable dopant. The density functional theory DFT calculations are performed for doped graphene using Boron, Sulphur and phosphorus as dopants to improve the quantum capacitance of electrodes fabricated using graphene. The calculations are performed at temperatures of 233, 300 and 353 degrees K. From present calculations no significant temperature dependence of quantum capacitance is observed, however a marked increase in QC of value above 58Fcm(-2) is seen. Forphosphorus and Sulphur doped graphene a significant energy gap shift of similar to 1.5 eV from the Fermi level is observed that significantly increases the QC at Fermi level to a high value of similar to 35 mu Fcm(-2). With boron dopant as well, a shift of energy gap similar to 1.25eV from the Fermi level is observed. The shift in Dirac point increases quantum capacitance at Fermi level that in turn can increase the energy density of supercapacitor remarkably. The effect of increasing doping concentration on quantum capacitance is also investigated. These results suggest that doping of graphene may result in significant increase in QC near Fermi level, if the dopants are selected carefully depending upon the use of graphene as a positive or negative electrode. The results of these calculations reveal that the problem of low QC of graphene in the range of interest can be addressed by modifying itssurface and structure chemistry which may increase energy density in supercapacitors. SERB Department of Science and Technology (Government of India) [ECR/2016/001871] The authors would like to acknowledge University Science and Instrumentation Centre, USIC, JNU, Delhi for providing the computing resources. Authors acknowledge the financial support received from the SERB Department of Science and Technology (Government of India) file no. ECR/2016/001871. The numerical calculations reported in this paper were partially performed at TUBITAK ULAKBIM (TURKEY), High Performance and Grid Computing Centre (TRUBA resources). WOS:000593208300006
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- 2020
5. PVDF-HFP and 1-ethyl-3-methylimidazolium thiocyanate–doped polymer electrolyte for efficient supercapacitors.
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Tuhania, Pankaj, Singh, Pramod K., Bhattacharya, B., Dhapola, Pawan S., Yadav, Shivani, Shukla, P. K., and Gupta, Meenal
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POLYVINYLIDENE fluoride ,THIOCYANATES ,IMIDAZOLES ,SUPERCAPACITORS ,POLYELECTROLYTES ,DOPING agents (Chemistry) - Abstract
The sole aim of the present article is to develop an ionic liquid (IL)-doped solid polymer electrolyte for an electrochemical double-layer capacitor (EDLC). A solution cast technique was adopted to develop a solid polymer electrolyte of poly (vinylidene fluoride-co-hexafluoropropylene) as host polymer and low-viscosity IL (1-ethyl-3-methylimidazolium thiocyanate) as dopant. Electrochemical impedance spectroscopy measurement showed a six orders of magnitude enhancement in conductivity (σ) by IL doping. A linear sweep voltammetric investigation of the electrolyte films exhibited a good electrochemical stability window of 3.6 V. Polarized optical microscopy of the synthesized films revealed a reduction in crystallinity by IL doping. Infrared spectroscopy further affirms the composite nature of the film. The maximum conductivity value of 2.65 mS/cm is obtained for 80% of the ionic-doped system. Using maximum conductivity film and porous carbon-based electrodes, we have developed EDLCs that show a specific capacitance value of 2.36 F/g. [ABSTRACT FROM AUTHOR]
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- 2018
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6. Polyvinylpyrrolidone (PVP) with Ammonium Iodide (NH4I) and 1‐Hexyl‐3‐Methylimidazolium Iodide Ionic Liquid Doped Solid Polymer Electrolyte for Efficient Supercapacitors.
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Singh, Diksha, Gupta, Meenal, Singh, Ram Chandra, Pandey, Shri Prakash, Karn, Rakesh Kumar, and Singh, Pramod Kumar
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SUPERCAPACITORS , *SUPERIONIC conductors , *FOURIER transform infrared spectroscopy , *CONDUCTING polymers , *IONIC liquids , *POROUS polymers , *POLYELECTROLYTES - Abstract
Ionic liquid‐doped poly(vinylpyrrolidone), ammonium iodide (NH4I) ion conducting polymer electrolytes are prepared by solution cast technique. Ionic liquid (IL), 1‐hexyl‐3‐methylimidazolium (HMImI) is then added to increase the ionic conductivity of polymer electrolytes by reducing the crystallinity of polymer electrolyte. Fourier transform infrared spectroscopy confirms the complex formation as well as composite nature. Polarized optical microscopy affirms the reduction of crystallinity in polymer electrolyte by IL doping. Electrochemical double layer capacitors are then assembled using maximum conducting polymer electrolyte and porous carbon‐based electrodes which shows excellent specific capacitance. [ABSTRACT FROM AUTHOR]
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- 2019
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7. Theories and models of supercapacitors with recent advancements: Impact and interpretations
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Ashwani Kumar, Ramesh Chandra, Meenal Gupta, Yogesh Kumar, Gulzar Ahmed, Bharti, Ravikant Adalati, Patrizia Bocchetta, Baniwal, Bharti, Kumar, Ashwani, Ahmad, Gulzar, Gupta, Meenal, Bocchetta, Patrizia, Adalati, Ravikant, Chandra, Ramesh, and Kumar, Yogesh
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Supercapacitor ,Materials science ,chemistry ,Hardware_GENERAL ,supercapacitors, pseudo-capacitance, redox-reactions, compact layer, carbon ,chemistry.chemical_element ,Nanotechnology ,General Medicine ,Carbon - Abstract
Supercapacitors provide remarkable eco-friendly advancement in energy conversion and storage with a huge potential to control the future economy of the entire world. Currently, industries focus on the design and engineering aspects of supercapacitors with high performance (high energy), flexibility (by the use of composite polymer based electrolytes), high voltage (ionic liquid) and low cost. The paper reviews the modelling techniques like Empirical modelling, Dissipation transmission line models, Continuum models, Atomistic models, Quantum models, Simplified analytical models etc. proposed for the theoretical study of Supercapacitors and discusses their limitations in studying all the aspects of Supercapacitors. It also reviews the various software packages available for Supercapacitor (SC) modelling and discusses their advantages and disadvantages. The paper also reviews the Experimental advancements in the field of electric double layer capacitors (EDLCs), pseudo capacitors and hybrid/asymmetric supercapacitors and discusses the commercial progress of supercapacitors as well.
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- 2021
8. Recent advances in the application of biochar in microbial electrochemical cells.
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Patwardhan, Sanchita Bipin, Pandit, Soumya, Kumar Gupta, Piyush, Kumar Jha, Niraj, Rawat, Jyoti, Joshi, Hem C., Priya, Kanu, Gupta, Meenal, Lahiri, Dibyajit, Nag, Moupriya, Kumar Thakur, Vijay, and Kumar Kesari, Kavindra
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MICROBIAL fuel cells , *ELECTRIC batteries , *FUEL cell electrodes , *MICROBIAL cells , *SOIL stabilization , *CARBONIZATION , *ACTIVATED carbon , *BIOCHAR - Abstract
[Display omitted] • Various characteristics of biochar are discussed for their application in MFCs. • Different methods of biochar synthesis are elaborated. • Emerging methods are explained to estimate biochar potential and its life cycle assessment. • The advantages and environmental applications of biochar are described. • Analytical studies focusing on the ability of biochar catalyst are discussed in poison detection. The International Biochar Initiative classifies biochar as "a solid material derived from the carbonization of biomass." Biochar is a solid substance produced during the thermochemical degradation of biomass. This paper describes several examinations that have been conducted to investigate novel utilization of biomass since biochar is affordable, environmentally beneficial, and can be utilized for diverse purposes, such as soil stabilization, wastewater treatment, greenhouse gas management and power generation. Biochar has also been applied in fuel cells and supercapacitors, according to the latest reports. Biochar has the potential to be new and tenable material for microbial fuel cell electrodes. Biochar MFCs made through pyrolysis and gasification, exhibited significant performance as compared to activated carbon and graphite granule. This paper emphasizes the use of biochar as electrodes in MFCs to facilitate the simultaneous treatment of wastewater and electricity generation while also providing additional commercial advantages. Applications of biochar in microbial fuel cells as separator membrane and cathode catalysts are also mentioned. Brief information on the future prospects of the use of biochar in microbial fuel cells is further summarized. [ABSTRACT FROM AUTHOR]
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- 2022
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9. The Effect of Modifications of Activated Carbon Materials on the Capacitive Performance: Surface, Microstructure, and Wettability
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Kouao Dujearic-Stephane, Vivek Sharma, Ashwani Kumar, Soumya Pandit, Patrizia Bocchetta, Meenal Gupta, Yogesh Kumar, Dujearic-Stephane, Kouao, Gupta, Meenal, Kumar, Ashwani, Sharma, Vijay, Pandit, Soumya, Bocchetta, Patrizia, and Kumar, Yogesh
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Materials science ,Heteroatom ,Oxide ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,lcsh:Technology ,01 natural sciences ,chemistry.chemical_compound ,medicine ,activated carbon ,lcsh:Science ,Engineering (miscellaneous) ,Conductive polymer ,Supercapacitor ,supercapacitors ,lcsh:T ,Carbonization ,carbon precursor ,021001 nanoscience & nanotechnology ,nano-structured porous electrode ,BET analysis ,0104 chemical sciences ,chemistry ,Chemical engineering ,Ceramics and Composites ,Surface modification ,lcsh:Q ,0210 nano-technology ,Carbon ,Activated carbon ,medicine.drug - Abstract
In this review, the efforts done by different research groups to enhance the performance of the electric double-layer capacitors (EDLCs), regarding the effect of the modification of activated carbon structures on the electrochemical properties, are summarized. Activated carbon materials with various porous textures, surface chemistry, and microstructure have been synthesized using several different techniques by different researchers. Micro-, meso-, and macroporous textures can be obtained through the activation/carbonization process using various activating agents. The surface chemistry of activated carbon materials can be modified via: (i) the carbonization of heteroatom-enriched compounds, (ii) post-treatment of carbon materials with reactive heteroatom sources, and (iii) activated carbon combined both with metal oxide materials dan conducting polymers to obtain composites. Intending to improve the EDLCs performance, the introduction of heteroatoms into an activated carbon matrix and composited activated carbon with either metal oxide materials or conducting polymers introduced a pseudo-capacitance effect, which is an additional contribution to the dominant double-layer capacitance. Such tricks offer high capacitance due to the presence of both electrical double layer charge storage mechanism and faradic charge transfer. The surface modification by attaching suitable heteroatoms such as phosphorus species increases the cell operating voltage, thereby improving the cell performance. To establish a detailed understanding of how one can modify the activated carbon structure regarding its porous textures, the surface chemistry, the wettability, and microstructure enable to enhance the performance of the EDLCs is discussed here in detail. This review discusses the basic key parameters which are considered to evaluate the performance of EDLCs such as cell capacitance, operating voltage, equivalent series resistance, power density, and energy density, and how these are affected by the modification of the activated carbon framework.
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- 2021
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