Physics - Research Publications
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Item Preparation and Energy Storage Assessment of Ti3C2 2d MXene and Its Possible Thinning Mechanism(Springer Nature, 2023-09-07T00:00:00) Singh, Diya; Rani, Pinki; Biswas, Sayani; Alegaonkar, Prashant S.Since after its discovery, MXene has captivated the focus of many researchers. In this work, we report on the low-temperature synthesis of Ti3AlC2 MAX phase at 800�? and its further etching to obtain Ti3C2 MXene. Initially, titanium (Ti), aluminium (Al), and graphite (C) precursors were taken in an appropriate volume proportion and add-mixed and grounded well via molten salt technique (Galvin et al. in J Eur Ceram Soc 38, 2018 [1]). The characterizations performed on powder such as FTIR, XRD, UV�Visible, SEM, and EDS confirmed Ti3AlC2 MAX phase. The MAX phase was subjected to the acid treatment (HF, concentration 40%) for ~ 80�h. The synthesized MXene was separated and investigated using FTIR, XRD, UV�Visible, SEM, and EDS techniques. The MXene was further employed to microwave treatment over the temperature 300�420�K at a discharge of power 120 W for 1�h. Analysis revealed that thickness of Ti3C2 layers is observed to be decreased with microwave treatment which can be a possible mechanism to obtain MXene quantum dots. In electrochemical analysis, specific capacitance for two electrode MXene@300�K and @400�K is reported to be 15 and 10�F/g, respectively, showing resistive nature of capacitance coupling for MXene. Analysis of electrochemical impedance spectroscopy together with bode showed the surface passivation effect of MXene layers to achieve different charge dynamics in both the systems. � 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item All-redox hybrid supercapacitors based on carbon modified stacked zinc cobaltite nanosheets(Royal Society of Chemistry, 2023-09-12T00:00:00) Kour, Simran; Kour, Pawanpreet; Sharma, A.L.The role of energy in the present century has increased with the fast advancement of the global economy. In this regard, hybrid supercapacitors (HSCs) as energy storage systems have become an extensive research focus worldwide. This study reports the synthesis of carbon-loaded ZnCo2O4 stacked nanosheets via an in situ hydrothermal process followed by annealing. The electrochemical response was tested in a 2-electrode system. The optimized composite exhibited a capacitance of ?527.6 F g?1 at 5 mV s?1. The symmetric SC (SSC) possessed an energy density (Ed) of ?17.3 W h kg?1 corresponding to a power density (Pd) of 2.25 kW kg?1. Two asymmetric all-redox HSCs have also been fabricated using an optimized composite material as the positive electrode. The previously synthesized MnCo2O4/AC (HSC1) and MnO2/AC (HSC2) were taken as negative electrodes. HSC1 exhibited an Ed of ?24.4 W h kg?1 corresponding to a Pd of ?0.8 kW kg?1. On the other hand, HSC2 exhibited the highest Ed of ?30.8 W h kg?1 at 2.4 kW kg?1. The real-time application of the composite is tested with the fabricated HSCs. HSC1 exhibited a capacitive retention of ?72.2% after 10 000 cycles. On the other hand, HSC2 exhibited a capacitive retention of ?73.4% after 10 000 cycles. The SSC, HSC1, and HSC2 illuminated a 39 red LED panel for ?3 min, 7 min, and 13 min, respectively. The results suggested the promising performance of all-redox HSCs. The overall results present a sustainable approach for creating hierarchical energy materials for the construction of future energy-storage systems. � 2023 The Royal Society of Chemistry.Item MoSe2-FeOOH nanocomposite as hybrid electrode material for high-performance symmetric supercapacitor(Elsevier Ltd, 2022-12-29T00:00:00) Tanwar, Shweta; Arya, Anil; Sharma, A.L.Molybdenum diselenide-based composite has been considered a potential material in the supercapacitor application due to its variable oxidation states, high surface area, and electronic conductivity. This report presents the composite formation of molybdenum diselenide nanoflowers and iron oxide-hydroxide nanorods utilizing a hydrothermal route assisted by room temperature chemical blending technique. The symmetric cell designed based on prepared composite material delivers the specific capacitance of 132 F g?1 for 1 A g?1 for a 1 V voltage. It shows 100% capacitance retention for 3000 cycles and 100% coulombic efficiency for 10,000 cycles at 1 A g?1. It provides an energy density of 18.3 Wh kg?1 at 1174 W kg?1 power density. The practical application associated with the designed symmetric cell based on the composite electrode was confirmed via the illumination of the panel comprising 42 red LEDs for 10 min effortlessly without break. Additionally, a self-proposed charge mechanism has been incorporated for an enhanced understanding of the reader. The improved results indicate the point that the prepared electrode material has good capability for high-performance supercapacitors. � 2022Item Electrochemical performance of mixed-phase 1T/2H MoS2 synthesized by conventional hydrothermal v/s microwave-assisted hydrothermal method for supercapacitor applications(Elsevier Ltd, 2022-07-05T00:00:00) Kour, Pawanpreet; Deeksha; Yadav, KamleshMixed-phase 1T/2H MoS2 has been receiving immense attention as an electrode material for supercapacitors due to the synergistic effects of both the phases. Herein, we synthesized mixed-phase 1T/2H MoS2 via two different techniques: conventional hydrothermal (HT) and microwave-assisted hydrothermal (MHT) technique. The formation of MoS2 is confirmed through X-ray diffraction pattern, scanning electron microscopy, energy dispersive X-ray spectroscopy, Raman-spectra, and X-ray photoelectron spectra. The electrochemical performance of the two samples is investigated using cyclic voltammetry (CV), Gravimetric charging-discharging (GCD) and electrochemical impedance spectroscopy (EIS). MoS2 synthesized via MHT method (MS-MW) and HT method (MS-HT) deliver capacitances of 421 F g?1 and 742 F g?1 at 5 mV s?1, respectively. The energy density of MS-HT (57 Wh kg?1) is almost double than that of MS-MW (30 Wh kg?1). MS-HT also exhibited remarkable capacitance retention of 91% over 1200 cycles, compared with MS-MW. The results demonstrate that MoS2 synthesized by the hydrothermal method delivers superior electrochemical performance. � 2022 Elsevier B.V.Item Synergistically modified WS2@PANI binary nanocomposite-based all-solid-state symmetric supercapacitor with high energy density(Royal Society of Chemistry, 2022-03-09T00:00:00) Iqbal, Muzahir; Saykar, Nilesh G.; Alegaonkar, Prashant S.; Mahapatra, Santosh K.The rapid development of intelligent, wearable, compact electronic equipment has triggered the need for durable, flexible, and lightweight portable energy storage devices. Nanomaterials that are capable of delivering the high specific power density and commensurate energy density are potential candidate for realizing such devices. Herein, we report the facile synthesis of a binary nanocomposite WS2@PANI by utilizing hydrothermal and physical blending techniques to assess it as an electrode material for high-performance supercapacitors. The nanocomposite electrode delivered specific capacitance >335 F g?1 @ 10 mV s?1 (two-electrode), achieving energy and power densities of ?80 W h kg?1 and ?800 W kg?1, respectively, with capacitance retention of 83% even after 5000 charge-discharge cycles @ 10 A g?1, all of which are superior to the WS2 electrode. Dunns model quantifies capacitive and intercalative contributions that showed the cumulative effect of both to realize a robust, cost-effective, and energy-efficient device. The strategically incorporated PANI broadened the electrochemical window and the device's overall performance, resulting in high specific energy density. We demonstrated that our all-solid-state symmetric supercapacitor could be used to illuminate a light-emitting diode and drive a rotary motor. We believe that our WS2@PANI binary nanocomposite will be a potential candidate for energy storage devices. � 2022 The Royal Society of ChemistryItem Insights into the use of polyethylene oxide in energy storage/conversion devices: A critical review(Institute of Physics Publishing, 2017) Arya, A.; Sharma, A.L.In this review, the latest updates in poly (ethylene oxide) based electrolytes are summarized. The ultimate goal of researchers globally is towards the development of free-standing solid polymeric separators for energy storage devices. This single free-standing solid polymeric separator may replace the liquid and separator (organic/inorganic) used in existing efficient/smart energy technology. As an example, polyethylene oxide (PEO) consists of an electron donor-rich group which provides coordinating sites to the cation for migration. Owing to this exclusive structure, PEO exhibits some remarkable properties, such as a low glass transition temperature, excellent flexibility, and the ability to make complexation with various metal salts which are unattainable by another polymer host. Hence, the PEO is an emerging candidate that has been most examined or is currently under consideration for application in energy storage devices. This review article first provides a detailed study of the PEO properties, characteristics of the constituents of the polymer electrolyte, and suitable approaches for the modification of polymer electrolytes. Then, the synthesization and characterizations techniques are outlined. The structures, characteristics, and performance during charge-discharge of four types of electrolyte/separators (liquid, plasticized, and dispersed and intercalated electrolyte) are highlighted. The suitable ion transport mechanism proposed by researchers in different renowned groups have been discussed for the better understanding of the ion dynamics in such systems. ? 2017 IOP Publishing Ltd.Item Development of novel cathode materials based on MWCNT for energy storage/conversion devices(Springer Science and Business Media, LLC, 2017) Agnihotri, Shruti; Rattan, Sangeeta; Sharma, A. L.In Chap. 1, already available technology for energy storage solutions like capacitors, lead acid batteries, compressed air energy storage, flywheels has been discussed in order to compare their energy and power densities. Emphasis has been laid on Rechargeable Lithium ion Battery (Li-ion). Various materials which are already explored and used as cathode of battery has also been discussed with their merits and demerits. Further introduction of prepared orthosilicate material with used conductive additive Multiwalled carbon nano tube (MWCNT) has also given. In Chap. 2, methodology used to prepare respective Li2MnFeSiO4 material and its composite with MWCNT has been discussed in detail. Further, in order to validate its electrochemical application, different steps of cell assembly of Lithium half cell fabrication has also been discussed. Chapter 3 comprises of results obtained using standard Field emission scanning electron microscope (FESEM). Effect of used MWCNT on its morphology has been discussed in this chapter. A.C Impedance spectroscopy has been used to study variation in conductivity with respect to bared material. Possible reasons for increased conductivity with morphology has also been discussed in discussion. Chapter 4 includes conclusions drawn from mentioned results. This chapter summarizes measured conductivity values with different concentrations of MWCNT. Improved conductivity with respect to bared orthosilicate material has been pointed in this chapter. ? Springer International Publishing Switzerland 2017.