Browsing by Author "Singh, Nirbhay"

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Advanced cyclic stability and highly efficient different shaped carbonaceous nanostructured electrodes for solid-state energy storage devices
(Elsevier Ltd, 2022-07-12T00:00:00) Singh, Nirbhay; Tanwar, Shweta; Sharma, A.L.; Yadav, B.C.
The most reliant storage technologies are batteries and supercapacitors. While supercapacitors are more efficient in terms of faster energy delivery, sustainability, and high capacity retention. In supercapacitors, mostly utilized precursors are least abundant which are toxic and costly, as well as facing structural stability issues during the advanced charging-discharging cycles. So in the present work, we have studied the sustainability and capacity retention profile of shape-dependent carbonaceous materials in terms of cyclic stability. Here, we have prepared an environment-friendly, cost-effective carbon@FeOOH composite series by low-temperature hydrothermal method. The galvanostatic charge-discharge analysis shows a high power density of 5000 W kg?1 at a current density of 10 A g?1. The advanced capacity retention up to 92% is seen up to 15,000 cycles and 100% Coulombic efficiency till the last segment (30000th segment of charging-discharging) of galvanostatic charge-discharge (GCD) for optimized mesoporous carbon@FeOOH (MCF) sample. The symmetric solid-state device comprising MCF electrodes has been fabricated at the laboratory scale. It has been able to glow red LED for 18 min and a panel consisting of 16 LEDs for 5 min. A self-explanatory mechanism has also been proposed for a better understanding of readers. � 2022 Hydrogen Energy Publications LLC
Advanced sustainable solid state energy storage devices based on FeOOH nanorod loaded carbon@PANI electrode: GCD cycling and TEM correlation
(Elsevier Ltd, 2023-03-09T00:00:00) Singh, Nirbhay; Tanwar, Shweta; Kumar, Pradip; Sharma, A.L.; Yadav, B.C.
A cost-effective, environment-friendly polyaniline-wrapped activated carbon-FeOOH ternary composite electrode is developed by two steps facile method for the efficient and sustainable energy storage device. The HR-TEM analysis before and after cyclic stability (20 k cycles of charging-discharging) shows electrode structural stability and potentiality as an energy storage device. The ternary composite utilizes polyaniline (PANI) maximum, which reflects an increase in voltage window, and electrochemical performance. The voltammetry (cyclic) and galvanostatic charge-discharge (GCD) examination display specific capacitance of 213 F g?1 at 10 mV s?1 and 234 F g?1 at 2 mA sec?1 for 20 wt%. The drastic variation through EIS (electrochemical impedance spectroscopy) in equivalent series resistance is seen by the nyquist plot before and after cycling. The specific capacitance is 234.5 F g?1 at 1 Ag?1 for 20 wt% PANI composite. The energy(Ed) and power density (Pd) of the device are 45 W h kg?1 and 5997 W kg?1 at 2 mA and 20 mA, respectively. The fabricated device shows very advanced capacity retention of up to 89% and coulombic efficiency of 100% till the last 20 k cycles with a stable potential window. The fabricated device can glow LED panels (consisting of 26 LEDs) for up to 5.30 min. The device retention profile and stable potential window show its advanced structural stability up to commercial-scale cycling, which signifies the additional role of PANI. The HR-TEM and electrochemical results after cyclic stability are in correlation. � 2023 Elsevier B.V.
Aging impact of Se powder on the electrochemical properties of Molybdenum selenide: Supercapacitor application
(Elsevier Ltd, 2022-02-10T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.
In the present report, we have studied the impact of aging on selenium (Se) powder in hydrazine hydrate (act as reducing agent) during synthesis of pure molybdenum selenide (MoSe2) material. The MoSe2 as electrode material is prepared via single-step hydrothermal technique with aging Se powder in reducing agent for zero, one, and three days. The structural, microstructural, and chemical nature analysis of the samples was done via XRD, FESEM, and FTIR tools whereas the electrochemical study was performed via CV, GCD, and EIS techniques. The optimized material coded as M 39 (three days aged sample with pH 9) shows a high specific capacitance (Cs) of 368 F g?1 at the current density of value 0.5 A g?1 along with an energy density of 51 Wh kg?1 and power density of 250 W kg?1. Based on the electrode's electrochemical outcomes, it may be indicated that the electrochemical performance of MoSe2 material upsurges as the aging of Se increases from zero to three days. From the obtained results it is could be predicted that the M 39 material may stand appropriate for commercial supercapacitors. � 2022
Economic and environment friendly carbon decorated electrode for efficient energy storage devices
(Elsevier Ltd, 2023-04-26T00:00:00) Singh, Nirbhay; Tanwar, Shweta; Sharma, A.L.; Yadav, B.C.
The most dependent storage technologies are secondary batteries and supercapacitors. Supercapacitors are more competent regarding faster energy supply, sustainability, and high-capacity retaining. However, in supercapacitors, most research comprises the least abundant materials that raise the cost and toxicity, which are unfavorable to the environment. Therefore, we have prepared activated carbon-based earth-abundant iron oxyhydroxide material via a low-temperature hydrothermal technique. The key finding of this research is sustainable materials, with co-related studies of TEM and GCD cyclic stability (pre and post-cycling characterizations up to 10k). The X-ray photoelectron spectroscopy analysis reveals the elemental composition of the optimized sample. The electrochemical performance has been tested via galvanostatic charge-discharge analysis, electrochemical impedance spectroscopy, and cyclic voltammetry. The cyclic stability evaluation is done to see the lasting usability of the device for the 10,000th number of charging-discharging cycles, which is supported by electrochemical impedance spectroscopy results in form of a Nyquist plot. The galvanostatic charge-discharge analysis revealed the specific capacitance of 372 F g?1 at 2 mA. The specific energy and power density were obtained as 40 Wh kg?1 and 4200 W kg?1, respectively. The ACF1 shows Coulombic efficiency and capacity retention as 96 % and 80 %, respectively, up to 10k cycles. We have proposed a charge storage mechanism for the fabricated electrode. A supercapacitor has been made-up and tested for the glow of LED, and the device can glow LED for 20 min. The device was repeated after two months and reproduced the LED glow for the same duration. � 2023 Elsevier Ltd
Electrochemical performance investigation of different shaped transition metal diselenide materials based symmetric supercapacitor with theoretical investigation
(Elsevier B.V., 2023-10-11T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Vijayan, Ariya K.; Sharma, A.L.
Transition metal diselenide-based electrodes for hybrid symmetric supercapacitors appear as trending materials. Thereby in this paper, we report the preparation of different-shaped transition metal diselenides using a single-step hydrothermal route. The impact of the different morphology of the prepared transition metal diselenide material has been studied on their electrochemical performance. The nanoflower-shaped MoSe2 material was observed to deliver the highest electrochemical result than nanoneedles and nanospheres shape of CoSe2 and NiSe2 material respectively. The highest specific capacitance delivered by the MoSe2 material-based symmetric supercapacitor was 154 F g?1 at 10 mV s?1. It also exhibits a maximum energy density of 17 Wh kg?1 with 1267 W kg?1 power density. Further, the MoSe2-based symmetric supercapacitor has been utilized to burn different colors of light-emitting diodes along with a panel of 26 LEDs of red color. To make the working of the symmetric supercapacitor (MoSe2-based) easier to understand for the readers we have proposed a mechanism of charge storage associated with it. Additionally, the experimental finding has been supported by investigating the structural and electronic properties of MoSe2, CoSe2, and NiSe2 via density functional theory calculation. � 2023
Fabrication of activated carbon coated MSe2 (M=Mo, Co, and Ni) nanocomposite electrode for high-performance aqueous asymmetric supercapacitor
(Elsevier B.V., 2023-03-09T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.
Transition metal diselenides are trendy electrode materials for supercapacitors. The main reason behind it is their high specific capacitance. But, they suffer from poor electronic conductivity and agglomeration issues which hinder their practical use. Herein, we present the preparation of nanocomposites including transition metal diselenide MSe2 (M=Mo, Co, and Ni) with activated carbon using the facial hydrothermal route. Inspiring from the high electrochemical results of a hybrid nanocomposites symmetric cell, an aqueous asymmetric ultracapacitor cell (AUC) comprised of different shaped carbon-coated MSe2 (positive electrode) as well as activated carbon (AC) (negative electrode) has been fabricated. The NAC//6KOH//AC asymmetric cell displays the best outcomes among all fabricated devices. The specific capacitance observed is about 3740 F g?1 at 10 mV s?1. It delivers a high energy density of 69 Wh kg?1 along with a power density of 687 W kg?1 at 1 A g?1. The electrochemical results motivate us to explore the practical usability of the prepared NAC//6KOH//AC device via illuminating 26 red LED panels which glow for 26 min. The findings in this report indicate that MSe2-based nanocomposite has the scope and is a potential material in the energy storage field. � 2023 Elsevier B.V.
High efficient activated carbon-based asymmetric electrode for energy storage devices
(Elsevier Ltd, 2022-01-19T00:00:00) Singh, Nirbhay; Tanwar, Shweta; Yadav, B.C.; Sharma, A.L.
Electrodes are fabricated using activated carbon@FeOOH and MoSe2. The synthesis of both electrode materials individually is done by a one-step hydrothermal process. The structural, morphological and chemical information's are investigated by XRD, FESEM and FTIR respectively. The electrochemical properties are investigated by EIS, CV and GCD. The Nyquist plot gives the value of Rb and Rct as 1.0 ? and 1.3 ? respectively. The cell shows a maximum specific capacitance of 110 F/g at the scan rate of 40 mV/s and the GCD shows a specific capacitance of 87.5 F/g at a high current density of 10 A/g. The energy density and power density calculated at current density 10 A/g are 31.11 Wh kg?1 and 4479 W kg?1, additionally, the maximum power density is 16000 W/kg, which is obtained at a current density of 40 A/g. The cell shows structural stability up to 5000 cycles with a capacity retention of 79%. The overall electrochemical performance of asymmetric electrodes (activated carbon@FeOOH and MoSe2) indicated its potential application in supercapacitors at commercial scale. � 2022
High efficient carbon coated TiO2electrode for ultra-capacitor applications
(IOP Publishing Ltd, 2021-10-08T00:00:00) Tanwar, Shweta; Arya, Anil; Singh, Nirbhay; Yadav, Bal Chandra; Kumar, Vijay; Rai, Atma; Sharma, A.L.
The present paper reports the investigation of structural, optical, chemical bonding, and electrical properties of the carbon black (CB)/TiO2 composite synthesized via the standard sol-gel method. The structural and morphological properties have been investigated using x-ray diffraction and also field emission scanning electron microscopy to confirm the formation of the nanocomposite. The electrochemical performance of the two-electrode symmetric fabricated supercapacitor (SC) has been examined by complex impedance spectroscopy, cyclic voltammetry, and galvanostatic charge-discharge (GCD). The electrode CT15 (15% TiO2 in CB matrix) shows a high specific capacitance of 236 F g-1 at scan rate 10 mV s-1. The GCD illustrates good specific capacitance retention of 90.3% after 10 000 cycles and with energy density and power density values as 22 Wh kg-1 and 625 kW kg-1 respectively (at 1 A g-1) in the voltage window of 1.2 V. The CT15 electrode cell demonstrates superior electrochemical performance as compared to other electrodes. Electrochemical impedance spectroscopy (EIS) demonstrates the capacitive behaviour of the composite electrode with a low value of resistance. The SC cell having optimum performance has been chosen to demonstrate the glowing red light emitting diode. A mechanism has also been proposed based on received data parameters to validate the SC performance. � 2021 IOP Publishing Ltd.
High-performance different shape carbon decorated asteroidea-like cobalt diselenide electrode for energy storage device
(Elsevier Ltd, 2022-08-18T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.
Presently, the selenides-based transition metal appears to be one of the encouraging materials utilized in energy conservation, and storage applications. In this report, we presented the pure cobalt diselenide (CoSe2) and its composite with different shaped carbon using the one-step hydrothermal method. The CoSe2 with activated carbon composite exhibited the highest electrochemical performance among all prepared samples. It depicts retention of capacitance at around 80 % for 5000 cycles. A symmetric device prototype cell has been designed using a CoSe2/activated carbon composite electrode which displays the highest specific energy and power density as 83 Wh kg?1 at 1622 W kg?1. The maximum specific capacitance displayed by it is 886 F g?1 for a constant 10 mV s?1 Further, a possible charge storage mechanism related to the fabricated cell is proposed. The fabricated device application in practical life has been tested via a glowing panel containing 17 light-emitting diodes (LEDs) and its performance remains the same after six months too. The noteworthy improved capacity, good cycling stability, and high specific energy for the CoSe2 with activated carbon composite material is possibly considered a potential candidate for energy storage devices, and portable electronics. � 2022 Elsevier Ltd
High-performance symmetric supercapacitor based on activated carbon-decorated nickel diselenide nanospheres
(Springer, 2022-11-11T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.
The vital challenge is to advance the electronic conductivity of the transition metal diselenide for their supercapacitor application. In this report, nickel diselenide nanospheres and their decoration by activated carbon are reported by a one-step, surfactant-free hydrothermal technique. The activated carbon-decorated NiSe2 nanospheres (NAC) electrode displays high electrochemical performance than pure NiSe2 nanospheres due to more active sites, enhanced conductivity, and reduced diffusion path of electrons and electrolyte ions for maximum energy storage. The NAC electrode depicts a specific capacity of about 119 C g?1 at 0.3 A g?1. The fabricated symmetric supercapacitor using an NAC electrode shows a high specific capacitance of about 282 F g?1 at 10�mV�s?1. The cycle stability of 70% for ten thousand cycles is exhibited for the fabricated symmetric supercapacitor. It manifests high specific energy of 28�W�h�kg?1 and specific power of value 980�W�kg?1 at 1 A g?1. Device applicability with load is tested at laboratory scale by glowing different color LEDs, and a panel of 26 red LEDs illuminated for 56�min effortlessly. A self-explanatory mechanism has also been proposed to make it easier to realize the readers about glowing LEDs, and their panels. � 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.
Nanostructured Li2MSiO4 (M=Fe, Mn) Cathode Material for Li-ion Batteries
(CRC Press, 2021-09-02T00:00:00) Sharma, A.L.; Tanwar, Shweta; Singh, Nirbhay; Kumar, Vijay; Arya, Anil
Li-ion batteries have emerged as a highly efficient energy storage device due to its high energy density, low cost, cyclic stability, and have dominated the markets all over the world. The battery comprises of cathode, anode, and electrolyte. The cathode material is crucial as it affects the overall cell performance and is an area of research globally. The suitable anode material is graphite and the electrolyte is gel/solid electrolyte (LiPF6). Recently, orthosilicates (Li2MSiO4; M= Fe, Mn, etc) based cathode material emerged as an alternative of LiCoO2 and LiFePO4 cathodes. The inherent structural stability in silicates is attributed to low cost, presence of Si-O covalent bonding in structure, and availability of two Li+ for transportation. The presence of two Li results in high energy density. So, to further enhance the energy density, researchers have adopted a doping, surface modification approach. Keeping the advantages of orthosilicates based electrode in mind, this chapter explores the fundamentals of battery, followed by characteristics of cathode material and strategy to tune the performance of orthosilicates based electrode. The complete methodology in terms of synthesis and characterization of the orthosilicates electrode has been explained. Finally, an important advancement in the orthosilicates based electrode material in battery performance is summarized followed by future aspects. � 2022 Taylor & Francis Group, LLC.
Structural and electrochemical performance of carbon coated molybdenum selenide nanocomposite for supercapacitor applications
(Elsevier Ltd, 2021-12-14T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.
Among the recent trends of supercapacitor electrode materials, transition metal dichalcogenides based composite materials have become popular due to their ability to have high electronic conductivity, variable oxidation states, large surface area, a porous structure. Herein we report, a composite material based on MoSe2 as electrode prepared using a standard single-step hydrothermal strategy. The structural and morphological study of the prepared material confirms the formation of the composite. The specific surface area has been estimated using BET technique and found to 522 m2 g ? 1 with average pore diameter as 4.6 nm. In all prepared composite electrodes, M@AC 1:5 electrode exhibits the highest specific capacity of 514 F g ? 1 at a scan rate of 10 mV s ? 1 for potential window 1 V in KOH electrolyte solution. The electrochemical impedance spectroscopy (EIS) study of the M@AC 1:5 electrode shows good agreement with cyclic voltammetry and galvanostatic charge-discharge storage mechanism. The aqueous symmetric cell fabricated of M@AC 1:5 with 6 M KOH electrolyte exhibits energy and power density 39.4 Wh kg?1 and 704.5 W kg?1 respectively. It shows long cycle stability with 90% capacitance retention and 100% coulombic efficiency even after 10,000 cycles. Further, the symmetric cell of M@AC 1:5 material was applied for lighting red LED, which illuminated for 22 min. The charging /discharging mechanism has been proposed based on finding of results through different characterizations. The asymmetric supercapacitor has also been designed using two different electrodes (first M@AC 1:5 and second synthetic MWCNT) and shows energy density of 14.9 Wh kg?1 and power density of 496 W kg?1 respectively. The capacitance retention is maintained up to 86.6% while coulombic efficiency recorded 100% for 10,000 cycles. Thus, obtained results highly encouraging and appropriate for the commercial applications. � 2021 Elsevier Ltd
Structural, Electrical and Electrochemical Properties of Fe Doped Orthosilicate Cathode Materials
(Springer Nature, 2021-12-02T00:00:00) Singh, Nirbhay; Kanwar, Komal; Tanwar, Shweta; Sharma, A.L.; Yadav, B.C.
We report the paper related to the effect of Fe doping on the Li2FexMn1?xSiO4 (x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) cathode materials synthesized by Sol-Gel technique. X-Ray Diffraction evidences the monoclinic structure with space group Pn(7) and crystal size decreases from 43 to 35�nm on doping Fe in Li2MnSiO4. Field emission scanning electron microscopy (FESEM) confirms that particle size reduces from 60 to 21�nm with increase of Fe concentration. The impedance analysis shows that highest electrical conductivity was 4.5 � 10�5 Scm?1 for Li2Fe0.4Mn0.6SiO4 cathode material. The initial specific capacity was 152 mAhg?1 at the rate of 0.1 C and 131 mAhg?1 after the 50th cycle with 86% capacity retention. The doping of Fe enhanced the conductivity by reducing its charge transfer resistance and increasing Li-ion diffusion coefficient than the pure Li2MnSiO4 cathode material. � 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Structural, Microstructural and Electrochemical Properties of Carbonaceous Nanocomposite for Supercapacitor Applications
(Springer Nature, 2021-12-02T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Sharma, A.L.
In this paper, we prepared CCT nanocomposite comprising of Co3O4, carbon black and TiO2 via microwave-assisted sol�gel technique. The composite is designed as electrode material for supercapacitor application. We have synthesised two samples namely CT and CCT where CT is optimised composite of carbon black and TiO2 nanoparticle, and CCT is composite of Co3O4, carbon black and TiO2, respectively. The prepared electrode material has been characterised by X-ray diffraction, field emission scanning electron microscopy, cyclic voltammetry (CV), galvanostatic charging-discharging (GCD) and electrochemical impedances spectroscopy (EIS). The structural and microstructural characterisation of the material confirms the formation of the crystal structure and nanocomposite. The CCT material shows better specific capacitances of 250�F�g?1 at a rate of ten millivolts per second which is advanced than that of CT composite. The CCT sample exhibits energy density (Ed) of 46�W�h�kg?1 at corresponding power density (Pd) of value around two thousand watt per kilogram. The analysed result reveals that the prepared CCT nanocomposite can be considered as potential electrode material for supercapacitor applications. � 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Sustainable carbon coated ZrO2 electrodes with high capacitance retention for energy storage devices
(Institute of Physics, 2022-08-09T00:00:00) Singh, Nirbhay; Tanwar, Shweta; Kour, Simran; Sharma, A.L.; Yadav, B.C.
The rapid development of modern technology starves for future research to attain high-energy, high-power, and high cyclic stable energy-storage devices. Carbonaceous electrodes in supercapacitors provide a large-power device, which stores the charge between the surface of the carbonaceous electrode and the electrolyte layer. The commercially available electrode based on pure carbon suffers from low energy density. To overcome the mentioned issue, major efforts have been dedicated to enhancing the charge storage of carbonaceous electrodes by the addition of both pure capacitive material (such as Carbon and its derivative) and pure battery-type material (transition-metal oxide, hydroxides, etc). Mesoporous carbon due to its advanced feature along with ZrO2 good fit on performance and environmental aspect parameters. In this report, we have prepared environmentally friendly mesoporous carbon ZrO2 composite by the facile method, initially, ZrO2 is prepared hydrothermally after that mixing is done at room temperature to obtain the final product mesoporous carbon@ZrO2. The material structural, and microstructural examinations are done by x-ray diffraction analysis, and field emission scanning electron microscopy. The galvanostatic charging-discharging (GCD) analysis shows the specific capacitance of the device is 125 F g?1 and the energy density of the device is 25 Wh kg?1 at a current density of 0.5 A g?1. The GCD shows an extreme power density of 1201 W kg?1 at 1 mA. The cyclic voltammetry analysis shows the maximum specific capacitance of 54.5 F g?1 at 10 mV s?1. The long-term cyclic stability of up to 10 000 cycles is tested through GCD. The device shows high capacitance retention and Coulombic efficiency till the last GCD cycle at 82% and 100% respectively. The capacitive contribution is 55% for optimized electrodes. The prototype device formation and load light emitting diode (LED) testing are done at the laboratory. Based on experimental findings we have proposed a charge storage mechanism for a better understanding of readers. � 2022 IOP Publishing Ltd.