Browsing by Author "Tanwar, Shweta"

Now showing 1 - 20 of 32

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
Aging impact on morphological and electrochemical performance of MoSe2 composite for supercapacitor application
(Elsevier Ltd, 2023-02-27T00:00:00) Tanwar, Shweta; Sharma, A.L.
The report is associated with the investigation of the impact of selenium powder aging in hydrazine hydrate acting as a reducing agent on the electrochemical performance of the molybdenum diselenide/activated carbon (MoSe2@AC) composite-based electrodes, and its supercapacitor application. The MoSe2@AC composite is formulated via the simple hydrothermal method. The composite formation is validated via structural, chemical bond, and morphology investigation. Among all synthesized samples, six days aged sample coded M6AC appears to exhibit the best electrochemical performance. The specific capacitance estimated for M6AC material-based fabricated symmetric cell is around 394 F g?1 at the 1 A g?1 using KOH (6 M) electrolyte. The energy and power density delivered by the same cell at 1 A g?1 is about 55 W h kg?1 and 845 W kg?1 correspondingly. Furthermore, we have tested the real-world usability of the M6AC symmetric cell by illuminating different voltage cum colors light emitting diodes (LEDs). The 26 red LEDs in the parallel connection illuminate for approximately 32 min with the aid of our fabricated symmetric cell as the power source. For easy understanding of the readers, we also report the self-proposed charge storage mechanism linked with the glowing LEDs using our obtained experimental results. Thereby, the observed outcomes associated with the M6AC material indicate that it has immense potential for scaling its performance at the industrial cum commercial level to resolve the energy crisis problem of the society. � 2023
Construction of three-dimensional marigold flower-shaped Ni3V2O8 for efficient solid-state supercapacitor applications
(John Wiley and Sons Inc, 2022-06-13T00:00:00) Haldar, Krishna K.; Biswas, Rathindranath; Arya, Anil; Ahmed, Imtiaz; Tanwar, Shweta; Sharma, Achchhe Lal
Development of binary spinel-type mixed metal oxide and fabrication various morphological heterostructure nanomaterials having two distinct metals paid a wide attention in emerging field. Here, we prepared three-dimensional (3D) marigold flower-like Ni3V2O8 structure via a simple and facile technique for electrochemical supercapacitor applications. 3D Ni3V2O8 with thick petals as cathode materials exhibits high specific capacitance of 263.12 F g?1 at a scan rate of 0.5�mA cm?2. The high energy density of 32.98 W h kg?1 at power density of 189.96 W kg?1 is obtained by the cathode formation of marigold flower-shaped Ni3V2O8, indicating excellent ions accessibility and large charge storage ability of Ni3V2O8 structure. It is also observed that even after 5000 cycles charging-discharging profile analysis, Ni3V2O8 cathode retains 32% of its initial capacitance along with 100% Coulombic efficiency. This higher capacitance retention strengthens its adoption as a potential candidate for supercapacitor application. � 2022 John Wiley & Sons Ltd.
A critical review on orthosilicate Li2MSiO4 (M = Fe, Mn) electrode materials for Li ion batteries
(Institute of Physics, 2023-05-10T00:00:00) Pateriya, Ravi Vikash; Tanwar, Shweta; Sharma, A.L.
The development of novel electrode materials with good electrochemical performances is necessary for the expanded and varied applications of lithium-ion batteries, and this development heavily relies on cathode materials. Due to excellent thermal stability, abundance, low cost, and environmental friendliness, orthosilicate cathode materials Li2MSiO4 (M = Fe, Mn) has received a lot of attention recently. The present review article gives a glimpse into the characteristics, advantages, and recent progress of orthosilicate cathode materials. This review starts with a brief history and working mechanism of batteries, the advantages of cathode materials followed by types of cathode materials, various synthesis methods, and different techniques used for their characterization. The most current initiatives to enhance orthosilicate Li2MSiO4 type electrochemical performances were introduced in this review. We provide a critical assessment of the efficient modification techniques for the orthosilicate Li2MSiO4 type cathode materials in particular. These potential cathode materials� synthesis, structure, morphologies, and particularly electrochemical performances have been thoroughly examined. This evaluation, we hope, will clarify the sustained advancement of high-efficiency and reasonably priced Li-ion batteries. � 2023 IOP Publishing Ltd.
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.
Fabrication of energy storage EDLC device based on self-synthesized TiO2 nanowire dispersed polymer nanocomposite films
(Springer Science and Business Media Deutschland GmbH, 2021-05-24T00:00:00) Devi, Chandni; Swaroop, Ram; Arya, Anil; Tanwar, Shweta; Sharma, A.L.; Kumar, Sandeep
In this work, a systematic study of titanium oxide (TiO2) nanowires incorporated polymer nanocomposite (PNC) films prepared by a standard solution cast technique is reported. The structural, morphological, dielectric, and electrochemical properties were investigated thoroughly. The polymer nanocomposite films demonstrated improved electrical and electrochemical properties as compared to polymer�salt complex film. The morphological and structural properties have been examined by the field emission scanning electron microscope, Fourier transform infrared spectroscopy, and X-ray diffraction. It is observed that the maximum ionic conductivity is of the order of 10�5 S cm?1 exhibited by 0.5 wt% nanowire added polymer nanocomposite film. The ion transference number was close to unity for optimized film and stability window of about ~ 5�V. The shift of loss tangent peak toward the high-frequency window with nanowire addition indicates a decrease of the relaxation time. The optimized TiO2 nanowire dispersed polymer nanocomposite film has been used to fabricate the electric double-layer capacitor cells. The fabricated cell demonstrates the specific capacitance of about 57.5 F/g (at 10�mV/s). The calculated energy density and power density are 1.38 Wh kg?1 and 0.709�kW�kg?1, respectively. The Coulombic efficiency is 97.7% up to the 500 cycles for the fabricated cell. The prepared polymer nanocomposite has the potential to use it as electrolyte cum separator for solid-state electric double-layer capacitor applications. � 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.
Hierarchical template-free chestnut-like manganese cobaltite for high-performance symmetric and asymmetric supercapacitor
(Elsevier B.V., 2022-11-25T00:00:00) Kour, Simran; Tanwar, Shweta; Kour, Pawanpreet; Sharma, A.L.
In this work, template-free Chestnut-like MnCo2O4 microspheres are synthesized using a straight-forward hydrothermal process succeeded by calcination. Urea as a reducing/precipitating agent can play an essential role in controlling the morphology of the material without using any additional surfactants or templates. The effect of reducing agent (Urea) on the structural and morphological evolution of MnCo2O4 has been studied. The electrochemical performance of the synthesized materials is investigated in a real device two-electrode cell configuration (symmetric and asymmetric system) rather than a three-electrode configuration. The two-electrode system gives more accurate and practical evaluation of the capacitive behavior of the material. The MnCo2O4 displayed the highest capacitance of 245.34 F g?1 at 5 mV s?1 for 0�1 V in a symmetric cell configuration. It also held an energy density of 22.24 Wh kg?1 at 1500 W kg?1. The optimized sample showed outstanding cyclic performance with only 3% of capacitance loss after 5000 cycles. Based on the structural and electrochemical findings, a charge storage mechanism has been proposed for the symmetric SC. Furthermore, a hybrid asymmetric supercapacitor with MnCo2O4 as a cathode and the previously synthesized MnO2/AC as an anode is also fabricated which exhibited an energy response of 30.12 Wh kg?1 for a power of 7000 W kg?1. For practical applications, different colored LEDs (red, yellow, green, and blue) and a panel with six red LEDs have been illuminated. The panel with six red LEDs is illuminated for 12 mins. for symmetric supercapacitor and 18 mins. for asymmetric supercapacitor. All these remarkable outcomes suggested that the synthesized material has wide potential for supercapacitors. � 2022
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 of the sodium-ion conducting flexible polymer blend composite electrolytes for electrochemical double-layer supercapacitor applications
(John Wiley and Sons Inc, 2022-04-12T00:00:00) Sadiq, Mohd; Tanwar, Shweta; Raza, Mohammad Moeen Hasan; Aalam, Shah Masheerul; Sarvar, Mohd; Zulfequar, Mohammad; Sharma, A.L.; Ali, Javid
Herein, we present the synthesis of a nanocomposite blend of polyvinyl alcohol (PVA), polyethylene glycol (PEG), sodium nitrate (NaNO3), and various weight percent of nanofillers, BaTiO3, using a simple standard solution casting technique. The prepared nanocomposites are characterized in detail via techniques such as X-ray diffraction technique, field-emission scanning microscope, FTIR, and Raman spectra for confirming the crystal structure, morphology, and chemical bond formation within the samples, respectively. The suitable ionic conductivity of prepared samples is in the range of 10?4�10?8�S/cm at room temperature. Further, its maximum electrochemical stability window is ~4.1 V, and the ionic transference number is about 0.96 (15 wt%) at room temperature. The results associated with the optimized polymer nanocomposite motivated us to check its practical applicability for supercapacitors. The cyclic voltammetry of the fabricated cell based on optimized polymer as separator cum electrolyte appears as a distorted rectangle with no redox peaks. The cell charge storage mechanism is explored to be the electric double layer (EDLC) in nature. The maximum specific capacitance exhibited by the cell is nearly 4.4 F/g at a scan rate of 3 mV/s. The energy and power densities delivered by the same cell are equal to 27.7�W h kg?1 and 9972 W kg?1, respectively, which sustain for 100 cycles. The results of the designed cell reveal that both blend polymer composite electrolyte films and the composite electrode can be implemented to be used for EDLC supercapacitor. � 2022 John Wiley & Sons 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.
Insight into use of biopolymer in hybrid electrode materials for supercapacitor applications�A critical review
(American Institute of Physics Inc., 2023-05-12T00:00:00) Tanwar, Shweta; Sharma, A.L.
The shortage of natural resources due to the progression of the human population and environmental pollution has become crucial concern topics to resolve. One of the best ways to resolve this is to develop renewable energy-based storage systems. Supercapacitors are emerging as promising storage systems via providing rapid charging/discharging and high power delivery, but there is a need to explore low-cost, environment-friendly, non-toxic, abundant, and biodegradable electrode materials for supercapacitors. In this regard, biopolymers are observed to be popular for storage applications as they are of high porosity, cost-effective, easily available, low-weight, and environment friendly and have biodegradability properties. The biopolymer-based electrode has a desirable morphology and high surface area and exhibits admirable electrochemical properties. The focus of this report is to highlight (i) the inclusive details of supercapacitors and their types along with strategies to improve their electrochemical performance, (ii) biopolymers and their types used for supercapacitor applications, (iii) various synthesis routes that could be adopted for designing electrode materials based on biopolymers for supercapacitors, and (iv) challenges and future scope of biopolymers as the electrode material in supercapacitor applications. The detailed study here in this report is found to be a topic of interest for the scientific community to fabricate and prepare low-cost, eco-friendly, high electrochemical performance exhibiting electrode materials for supercapacitor applications. � 2023 Author(s).
Investigation of Structural and Electrochemical Properties for Orange Peel Derived Carbon
(Springer Science and Business Media Deutschland GmbH, 2023-05-21T00:00:00) Simple; Kushwaha, K.K.; Tanwar, Shweta; Sharma, A.L.
From this study, we get to know about the concentration effect of activating agent which is phosphoric acid (H3PO4) on the structural, and electrochemical behaviour of carbon produced from orange peel. We have taken various concentrations of H3PO4 (0.5�M, 1�M, 1.5�M) and activated the orange peel-derived carbon (OPC) followed by sintering in the furnace. The structural and chemical nature is analyzed by performing powder x-ray diffraction (XRD) and Fourier-transform infrared (FTIR) tools. The electrochemical measurements are also done via cyclic voltammetry (CV), galvanostatic charge�discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. At scan rate of 20�mV�s?1we discovered that sample named 1�M possess the greatest specific capacitance value of 5.55 F g?1. At the current density of 1 A g?1 specific energy is 0.189 Wh Kg?1 and specific power is 486.8 W Kg?1. As a result, raising the concentration of the solution from 0.5 to 1�M, there is a rise in electrochemical behavior but as we go from 1 to 1.5�M fall in the behavior is seen. The reason behind this is that in higher concentrations the specific area of the electrode for the ions to get accommodated decreases due to an increase in micropores. So, 1�M of 85% (w/v) H3PO4 will be a promising candidate for activating the orange peel-derived carbon (OPC) to obtain enhanced electrochemical performance for energy storage applications. � 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Mesoporous carbon/titanium dioxide composite as an electrode for symmetric/asymmetric solid?state supercapacitors
(Elsevier Ltd, 2022-08-27T00:00:00) Arya, Anil; Iqbal, Muzahir; Tanwar, Shweta; Sharma, Annu; Sharma, A.L.; Kumar, Vijay
This paper reports the successful synthesis of mesoporous carbon/titanium dioxide (MC/TiO2) composite electrodes via the hydrothermal method for supercapacitor (SC) applications. The morphology and structural properties of MC/TiO2 composites were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectra (FTIR). The electrochemical properties were recorded by cyclic voltammetry (CV) and galvanostatic charge/discharge (GCD) with an electrolyte (6 M KOH) in symmetric/asymmetric configuration. The specific capacitance (Cs) evaluated by CV is about 280F/g for composite electrode (95 % capacitance retention after 1000 cycles) and pristine has 150F/g @ 10 mV/s. Enhancement in capacitance is owing to faster charge dynamics within electrode material. The fabricated asymmetric device demonstrates high energy density (30.31 Wh/kg), than the symmetric configuration (?27 Wh/kg). Finally, both symmetric/asymmetric supercapacitors have illuminated a red LED, and strengthens the candidature of composite electrode for energy storage technology. � 2022 Elsevier B.V.
MnO2 nanorod loaded activated carbon for high-performance supercapacitors
(Elsevier Ltd, 2022-03-31T00:00:00) Kour, Simran; Tanwar, Shweta; Sharma, A.L.
Nowadays, transition metal oxides (TMOs) have gained much attention as potential candidates for supercapacitors owing to their remarkable properties for instance vast abundance, a high value of theoretical capacitance, easy accessibility, and eco-friendly nature. But low electric conductivity of TMOs restrains them from reaching their theoretically predicted value for capacitance. Activated carbon with enormous surface area and excellent conductivity has been chosen to augment the conductivity of TMO-based electrodes. Here in this paper, we have synthesized MnO2 nanorods via a facile hydrothermal process. These nanorods have been loaded onto activated carbon via a straight-forward sol-gel approach at room temperature. The obtained nano-composite exhibited superior capacitance of 398.5 F g?1 at 1 A g?1 than MnO2 (161.8 F g?1). The composite attained excellent energy of 105.2 Wh kg?1 (at 2 kW kg?1). Further, the composite was tested for device application. Three symmetric supercapacitor cells joined in series were proficient to glow a blue LED for about one minute while the red LED was illuminated for about 12 min. This suggested that the composite material has broad potential applicability as supercapacitor electrode material. � 2022 Elsevier B.V.