Faculty Publications
Permanent URI for this communityhttps://idr.nitk.ac.in/handle/123456789/18736
Publications by NITK Faculty
Browse
7 results
Search Results
Item Organic-inorganic hybrid mixed-valent bisphosphonate-polyoxovanadates composites with activated carbon for energy storage applications(Nova Science Publishers, Inc., 2024) Madhusree, J.E.; Banerjee, A.; Mal, S.S.In this book, we discuss the investigation of two different bisphosphonate-functionalized polyoxovanadate compounds for use in electrochemical energy storage applications. The compounds are (NH4)4[H6(VIVO2)(VV2O5)2O3P-C(O)(CH2-2-C5NH4)-PO32].9H2O (m), and (NH4)4[H6(VIVO2)(VV2O5)2O3P-C(O)(CH2-3-C5NH4)-PO32]. 8H2O (n). They have a mixed-valent oxovanadate polyanionic assembly that has two different pyridyl functional groups present on the organic bisphosphonate ligand. Several techniques have been used to characterize composites made from these compounds with activated carbon, including Fourier transform infrared spectroscopy, P-XRD, FESEM, EDX, and surface adsorption-desorption tests. The electrochemical performance of acidic electrolytic solutions containing 0.1 M H2SO4, AC-m, and AC-n electrode materials was investigated. Although the compounds are isotypic mixed-valence polyoxovanadate structures, their electrical behavior varies based on the position of the pyridyl group. AC-n was reported to have the most prominent specific capacitance of 313 F g-1 at a current density of 1 A g-1 in a voltage window of 0-1 V, with exceptional energy and power densities of 43.56 Wh kg-1 and 1999.72 W kg-1, respectively. At the same time, AC-m exhibited a specific capacitance of 212 F g-1 and a specific energy of 29.45 Wh kg-1. By lighting up different LED lights with only 42 mg of carbon clothcoated sample, the composite AC-n electrode displayed exceptional specific power. A further benefit of AC-n nanohybrids is their ability to retain electrochemical performance over time, which suggests long-term stability. © 2024 Nova Science Publishers, Inc. All rights reserved.Item Investigations of redox-active polyoxomolybdate embedded polyaniline-based electrode material for energy application(Springer Science and Business Media Deutschland GmbH, 2022) Anandan Vannathan, A.A.; Kella, T.; Shee, D.; Mal, S.S.Higher capacitance supercapacitors have received considerable attention, including their massive power density, high stability, and long cycle life. On the other hand, polymers have been known for their energy storage device application because of the pseudocapacitance behavior resulting from the extended conjugation over the polymer backbone. Here, we report a simple chemical bath deposition method for the synthesis of two polyoxometalates (H4[PVMo11O40] and H5[PV2Mo10O40]) impregnated polyaniline (PAni) composite (PVMo11@PAni and PV2Mo10@PAni) for electrochemical supercapacitors. Various analytical methods characterized the electrode materials, e.g., Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), powder X-ray diffraction (PXRD) method, and the morphological features of those electrodes were acquired by field emission scanning microscopy (FESEM). The exceptionally high average capacitance of 1371 F g−1 was obtained for the composite PVMo11@PAni electrode at a 3 A g−1 current density and 1 V potential window with an energy density of 137.5 W h kg−1. The PVMo11@PAni composite electrode showed almost 4.3 times the higher energy density than pure PAni and 2.3 times higher than PV2Mo10@PAni. In contrast, PV2Mo10@PAni composite showed 1.9 times more energy density than pure PAni composite electrode. Interestingly, high average capacitance, charge–discharge rates, and high energy density with high-level power delivery make them promising electrode candidates for supercapacitors. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Item High-performance hybrid supercapacitor-immobilized Wells-Dawson polyoxometalates on activated carbon electrodes(Royal Society of Chemistry, 2023) Madhusree, J.E.; Chandewar, P.R.; Shee, D.; Mal, S.S.The nanofabrication of electroactive hybrid materials for next-generation energy storage devices is becoming increasingly significant as supercapacitor (SC) technology develops rapidly. The present study utilizes activated carbon (AC) templates reinforced with Wells-Dawson polyoxotungstates (POMs) to produce nanohybrid electrodes for high-performance supercapacitors. This study analyzes Wells-Dawson polyoxotungstates (P2W18) for the first time integrated with AC, and its structural and electrochemical performances are discussed. First, the electrochemical performances of symmetric supercapacitors were characterized in an acidic aqueous electrolyte (0.5 M H2SO4). It was observed that a supercapacitor cell containing the 5 wt% AC-P2W18 hybrid symmetric displayed a noteworthy specific capacitance of 289 F g−1 and a remarkable energy density of 40 W h kg−1. Moreover, 5% AC-P2W18 symmetric supercapacitor cells showed 89% cyclic stability over 4000 cycles. Three LED lights were charged onto the electrode. The LEDs continued to illuminate continuously for red until 160 seconds, yellow until 20 seconds, and blue until 10 seconds after removing the electrode from the electrochemical workstation, demonstrating the device's power and energy density. © 2023 The Royal Society of Chemistry.Item High-performance electrochemical supercapacitors based on polyoxometalate integrated into polyaniline and activated carbon nanohybrid(Springer Science and Business Media Deutschland GmbH, 2023) Anandan Vannathan, A.A.; Kella, T.; Shee, D.; Mal, S.S.Polyaniline (PANI) and carbonaceous materials and metallic compounds have played a significant role in energy storage and conversion devices. PANI has demonstrated tremendous potential in the supercapacitor industry due to its high specific capacitance, high flexibility, and economical price. The CPs damage the hierarchical structure during the charging and discharging process and start swelling. Thus, incorporating polyoxometalates (POMs) into the conducting polymer matrix increases the stability of the electrode material. Here, we have demonstrated a comparative study of two newly synthesized composite materials consisting of K5H2[PV4W8O40] ·11H2O, (PV4W8) POM incorporated into two different supports, such as pseudocapacitive polyaniline (PANI) and EDLC activated carbon (AC) matrix. It was observed that the PANI-PV4W8 composite exhibited excellent capacitance nature at 0.5 M H2SO4 electrolyte solution than AC-PV4W8. The PANI-PV4W8 composite demonstrated the specific capacitance of 584 F g−1 at 0.8 A g−1. The composite also exhibited energy and power density of 81Wh kg−1 and 1598 W kg−1, respectively. Besides, the composite shows 93.13% capacity retention after 4500 cycles by cyclic voltammetry measurement at a 500 mV s−1 scan rate. Furthermore, the AC-PV4W8 showed a specific capacitance of 62 F g−1 at the current density of 0.6 A g−1. Interestingly, The PANI-PV4W8 composite could glow up the red and yellow LED bulb for more than a minute, suggesting a promising electrode material for practical supercapacitor purposes. © 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.Item Fabrication of supercapacitor electrode material using carbon derived from waste printer cartridge(Springer Science and Business Media Deutschland GmbH, 2024) Biradar, B.R.; Maity, S.; Chandewar, P.R.; Shee, D.; Das, P.P.; Mal, S.S.Transforming recyclable materials into a suitable product is an important area of research nowadays. This report demonstrates that carbon material derived from waste printer cartridges can be exploited to fabricate electrochemical cells—particularly supercapacitors (SCs). SCs are electrochemical energy storage devices currently attracting much attention in the research community due to their salient features, such as cost-effectiveness, extended cycle stability, and durability. Here, we report the results of thoroughly examining the effects of acidic, basic, and neutral aqueous electrolytes on printer waste carbon electrode material in SC efficiency. In our work, the waste carbon collected from used printer cartridges shows a specific capacitance of 178.4 F/g with energy and power density of 24.77 Wh/kg and 999.68 W/kg, respectively, at 0.5 A/g current density in acidic (1 M H2SO4) electrolyte medium. Moreover, it exhibited very promising capacitance of 135.04 F/g and 87.04 F/g in basic (1 M LiOH) and neutral (1 M NaCl) electrolyte medium, respectively, at 0.8 A/g current density with considerably better cycle stability. In an acidic medium, printer waste carbon drives a DC motor for 1 min with a three-cell series arrangement. The properties of that waste carbon (extracted from the cartridges) are similar to high-rate activated carbon available commercially. Graphical Abstract: (Figure presented.). © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.Item Synergistic Enhancement of Supercapacitor Performance: Vanadium-Substituted Phosphotungstic and Molybdic Acid Combined with Polypyrrole Using Pyridinium and Ammonium Ionic Containing Organic Cation Linkers with Improved Conductivity(John Wiley and Sons Inc, 2024) Puniyanikkottil, M.A.; Chandewar, P.R.; Shee, D.; Mal, S.S.High-performance energy-storage devices have emerged as a favored choice owing to their remarkable efficiency, sustainability, and environmental friendliness. Nowadays, polyoxometalate (POM)-based supercapacitor (SC) electrode materials have gained much attention. Herein, a few new POMs and ionic liquid (IL) composites incorporated into conducting polymer as electrode materials for SC applications are reported. The H6[PV3Mo9O40]⋅34H2O (PV3Mo9) and H6[PV3W9O40].34H2O (PV3W9) POMs are treated with tetrabutylammonium chloride and 1-butyl-4-methyl pyridinium chloride (BMP) and finally combined with polypyrrole (PPy) for the SC studies. An extensive array of analytical techniques is employed to delve into the interplay between the constituents within the composite materials, such as Fourier transform infrared spectroscopy, powder X-ray diffraction, thermogravimetric analysis, nuclear magnetic resonance (1H and 13C), Field-emission scanning electron microscopy, energy-dispersive X-ray stpectroscopy, X-ray photoelectron spectroscopy, and Brunauer-Emmett-Teller surface area. The combined application of these techniques enables us to understand the interaction dynamics within composite materials comprehensively. POM–ILs combination improves the solubility issues of POMs, and doping of PPy enhances the electrochemical performances of the materials. The PV3W9–BMP–PPy symmetric SC cell shows a specific capacitance of 294.79 F g−1 and an energy density of 28.89 Wh kg−1 at 1 A g−1 current density in 0.25 M H2SO4 medium followed by an excellent cycle life of 78.6% after 10,000 galvanostatic charge–discharge cycles. The fabricated SC device is performed to light up the bulbs of red, yellow, and green light emitting diodes for 50, 30, and 28 s, respectively. © 2024 Wiley-VCH GmbH.Item Carbon Nanotube-Supported Vanadium Substituted Phospho-Molybdate Nanohybrid for Supercapacitor Applications(John Wiley and Sons Inc, 2025) Biradar, B.R.; Swetha, M.T.; Thathron, N.; Puniyanikkottil, M.A.; Hanchate, A.; Das, P.P.; Mal, S.S.Owing to the depletion of conventional energy sources, our civilization is slowly transitioning to renewables. Therefore, designing effective energy storage systems is one of the most pressing technical demands. The quest for improved energy and power densities in energy storage devices, particularly those with long cycle life, has pushed the investigation of novel materials intended to build effective supercapacitors. In this work, nanohybrid materials are synthesized using a hydrothermal technique by mixing carbon nanotubes and a polyoxometalate cluster, H4[PVMo11O40].xH2O. Henceforth, this complex is acronymed as CNT-PVMo11. Further, electrochemical analysis of CNT-PVMo11 nanohybrid is carried out to examine various characteristics of the supercapacitor cell made with this nanohybrid. The cyclic voltammetry confirms the diffusive-dominant charge-storage process, quantifying a 72.83% diffusion mechanism at a scan rate of 1 mV s?1. The galvanostatic charge–discharge analysis of CNT-PVMo11 nanohybrid material showed a specific capacitance of 229.35 F g?1 with energy and power densities of 31.85 Wh kg?1 and 2000 W kg?1, respectively, at 1 A g?1 current density. The electrode material also shows 90% capacitance retention even after 6000 cycles at 8 A g?1 current density, indicating the material's remarkable stability. The high specific capacitance, excellent energy density, and impressive cycling stability of the hybrid material make it a promising candidate for next-generation supercapacitor electrodes. © 2025 Wiley-VCH GmbH.