Department Of Physics
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Item Synergistic improvement in electrochemical performance of Cr-doped MoS2/CuCo2S4 binary composite for hybrid supercapacitors(Elsevier Ltd, 2023-10-31T00:00:00) Kour, Pawanpreet; Kour, Simran; Deeksha; Sharma, A.L.; Yadav, KamleshThe synergistic effect of transition metal doping and composite formation can be imperative to improve the limited conductivity and inferior cyclic stability of MoS2 for supercapacitors. In this work, firstly, the impact of Cr-doping on the electrochemical activity of MoS2 has been discussed. Afterwards, the optimized Cr-doped MoS2 (CrMS-5) sample has been combined with CuCo2S4 (CCS) to further enhance its charge storage ability and cyclic stability. The CrMS-5/CCS composite delivers tremendous electrochemical activity as an electrode with a specific capacity of approximately 1324.08 C g?1 at 4 A g?1. The outstanding performance of the doped binary composite is on account of the synergism between doping and composite formation that results in increased conductivity and numerous redox active sites for charge storage. Furthermore, a symmetric supercapacitor device (SSC) has been fabricated using a CrMS-5/CCS electrode. It attains a high energy density of 46.63 Wh kg?1 corresponding to 1 kW kg?1 of power and exhibits remarkable cyclic stability of 81% for up to 5,000 cycles. The device illuminates a star-shaped LED panel of 12 red LEDs for 30 min. Thus, the above outcomes demonstrate the superiority of the doped MoS2-based composites for high-energy symmetric supercapacitors. � 2023 Elsevier LtdItem 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. � 2023Item Theoretical investigation of quantum capacitance of Co-doped ?-MnO2 for supercapacitor applications using density functional theory(Royal Society of Chemistry, 2023-09-07T00:00:00) Vijayan, Ariya K.; Sreehari, M.S.; Kour, Simran; Dastider, Saptarshi Ghosh; Mondal, Krishnakanta; Sharma, A.L.The rapid depletion of fossil fuels and ever-growing energy demand have led to a search for renewable clean energy sources. The storage of renewable energy calls for immediate attention to the fabrication of efficient energy storage devices like supercapacitors (SCs). As an electrode material for SCs, MnO2 has gained wide research interest because of its high theoretical capacitance, variable oxidation state, vast abundance, and low cost. However, the low electric conductivity of MnO2 limits its practical application. The conductivity of MnO2 can be enhanced by tuning the electronic states through substitution doping with cobalt. In the present work, first principles analysis based on density functional theory (DFT) has been used to examine the quantum capacitance (CQC) and surface charge (Q) of Co-doped MnO2. Doping enhanced the structural stability, electrical conductivity, potential window, and quantum capacitance of ?-MnO2. The shortened band gap and localized states near the Fermi level improve the CQC of ?-MnO2. For the narrow potential range (?0.4 to 0.4 V), the CQC is observed to increase with doping concentration. The highest CQC value at +0.4 V is observed to be 2412.59 ?F cm?2 for Mn6Co2O16 (25% doping), five times higher than that of pristine MnO2 (471.18 ?F cm?2). Mn6Co2O16 also exhibits better CQC and �Q� at higher positive bias. Hence, it can be used as an anode material for asymmetric supercapacitors. All these results suggest better capacitive performance of Co-doped ?-MnO2 for aqueous SCs and as an anode material for asymmetric supercapacitors. � 2023 The Royal Society of Chemistry.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 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).Item Self-assembled carbon wrapped manganese cobaltite nano-composite with promising electrochemical performance for symmetric and asymmetric supercapacitor device(Elsevier Ltd, 2023-05-27T00:00:00) Kour, Simran; Kour, Pawanpreet; Sharma, A.L.The growing energy requirements of modern society have led to an intensive search for advanced supercapacitor (SC) electrode materials. Binary transition metal oxides with excellent supercapacitive performance are among the most promising materials. However, the phase transformation of these metal oxides during repeated charging/discharging is a major concern, which depletes their cyclic performance. Coating metal oxides with carbon can provide structural stability to the metal oxide, thereby increasing their cyclic life. In addition, the highly conductive carbon enhances the capacitance of metal oxides by allowing the effective transfer of charges from MnCo2O4 to the current collector. In this study, self-assembled carbon-wrapped MnCo2O4 composite has been prepared through a two-step process involving hydrothermal and solution-mixing processes. The structural/electrochemical performances of the composites have been investigated. The optimized composite offered a maximum capacitance of 626.8 Fg?1 withholding 98 % of capacitance for 6000 cycles. Furthermore, the electrochemical performance of the composite has also been tested in an all-redox symmetric SC (SSC) as well asymmetric (ASC) configuration. In the symmetric cell, 30.2 Whkg?1 of energy is reported for 1.6 kWkg?1 of power. The asymmetric cell with the optimized composite as a cathode and MnO2/Activated carbon as an anode was fabricated. The ASC displayed 45.5 Whkg?1 of energy corresponding to 10 kWkg?1. Three SSCs/ASCs in series illuminated a panel of 39 red-LEDs for 9 and 15 min, respectively. The results suggest the promising performance of such composites for hybrid supercapacitors. Thus, the fabrication of all-redox-type SSCs/ASCs can be a futuristic approach for hybrid storage systems. � 2023 Elsevier LtdItem Study of Compatible Anode for Silicate-Based Cathode Material(Springer Science and Business Media Deutschland GmbH, 2023-05-21T00:00:00) Pateriya, Ravi Vikash; Tanwar, Shweta; Sharma, A.L.In the present paper, we have discussed the compatibility of suitable anode material with synthesized Li2MnSiO4 cathode material. The Li2MnSiO4 cathode material was synthesized by hydrothermal technique. The structural and electrochemical analysis were done by XRD, FTIR, and electrochemical measurement by cell assembly taking different materials as the anode. Cyclic voltammetry results show that cell prepared with Li2MnSiO4 as cathode and activated carbon as anode delivered a specific capacity of 53.07 mAh g?1 and graphite specific capacity of 10.21 mAh g?1 was calculated. Charge transfer resistance (Rct) of 6 and 7 ? were observed for cell with activated carbon and graphite anode respectively. Initial discharge capacity for activated carbon as an anode was recorded to be 70.54 and 3.97 mAh g?1 for anode with graphite. The results associated with activated carbon and Li2MnSiO4 as anode and cathode material appear to be compatible materials in Li-ion battery application. � 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item 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.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 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.