Department Of Physics
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Item 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 LtdItem 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.Item 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.Item 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 LLCItem 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. � 2022Item 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.