Papers by Balram Tripathi
Meeting abstracts, 2017
Lithium sulfur batteries with high charge-discharge rate capabilities are in great demand for hyb... more Lithium sulfur batteries with high charge-discharge rate capabilities are in great demand for hybrid vehicles, electric vehicles and portable electronic products. However uptill now its real applications are still plagued by rapid capacity fade mainly stemming from the polysulfide shuttle. High rate capability can be often enhanced by downsizing cathode materials to the nanoscale which increases the reaction surface to volume ratio but downsizing to less than 100 nm reduces the capacity. Ferroelectric materials have attracted much attention due to their unique ferroelectric, piezoelectric and ferroelastic properties. Coupling of highly polarized ferroelectric (BiFeO3) layer is an approach that can be used to enhance the higher rate characteristics and trapping of shuttle mechanism because ferroelectrics provides higher polarization which help to build up an internal electric field and induces macroscopic charges on the surface of the cathode. In Li-S batteries during discharge polysulfide shuttle causes capacity fade of the battery. We can speculate that polysulfide’s are heteropolar in which spontaneous polarization of ferroelectrics (BiFeO3) may solve the shuttle effect and can trap its formation for high rate performance Li-S batteries.
Batteries, May 26, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Indian Journal of Pure & Applied Physics, Oct 1, 2006
APL Materials, May 1, 2023
In this manuscript, we are reporting the role of ferroelectric nanoparticles (FNPs) coated separa... more In this manuscript, we are reporting the role of ferroelectric nanoparticles (FNPs) coated separators in capacity retention at high current density (200 mA/g) on S/SWCNT composite cathodes. The ferroelectric nanoparticles of Bi0.925Gd.075Fe0.95Ni0.05O3 (BGFNO) of spontaneous polarization 2.5 µC/cm2 were coated on commercial separators (PP) as well as doped in sulfur/SWCNT composite cathodes. Our results show a discharge capacity retention of 72% by using commercial separator polypropylene (PP); however, a capacity retention improvement of more than 100% was obtained for FNPs coated separator, which has been placed on the anode side as well as on the cathode side. It is observed that the FNPs coated separator due to spontaneous polarization on the anode and cathode side acts as a repulsive charge on the separator surface to retard polysulfide migration via electrostatic repulsion and protects the surface of lithium from dendrite formation due to which it gains high capacity retention as well as stability. The coated separator controls the transport of carrier ions and side reactions; however, the FNPs doped cathode acts as an absorption center for polysulfides to enhance the electrochemical performance of the cells. The significance of this study is to design an efficient methodology, which could protect electrodes from dendrite formation via coated separator and modified cathode with the FNPs via suppressing the polysulfide formation to achieve high capacity retention and electrochemical cycle stability.
Current nanomaterials, Sep 27, 2016
Background: Since last two decades, there has been rigorous efforts are going on to develop a hyd... more Background: Since last two decades, there has been rigorous efforts are going on to develop a hydrogen storage system for large-scale application in fuel cells, mobiles and for automotive uses. The early experimental data on hydrogen storage using CNTs contradicted theoretical calculations, and there has been a large variation in the CNT hydrogen storage capacity reported by various research groups. In present work, a comparative study on hydrogen storage and release characteristics of bare as well as three transition metals viz. Ni, Cu & Fe nanoparticles decorated MWCNT at ambient temperature i.e. 298K and pressure range of 9-16 atm has been studied. Methods: Synthesis, characterization and hydrogen adsorption-desorption behavior of bare as well as transition metal (Ni, Cu and Fe) decorated multiwalled carbon nanotubes has been studied systematically. Results: The maximum hydrogen storage capacities of finely dispersed Ni, Cu, and agglomerated Fe decorated and bare multiwalled carbon nanotubes measured at 298K were 0.812 wt% (at 15.85 atm), 2.59 wt% (at 12.64 atm), 0.909 wt % (at 15.45atm) and 0.654 wt% (at 12.84 atm) respectively. A mechanism invoking metal nanoparticle mediated dissociation of hydrogen molecule and its subsequent storage in carbon structure as well as defect sites has been proposed to explain hydrogen storage and release behavior of metal-decorated multiwalled carbon nanotubes. Conclusion: The nature and morphology of metal nanoparticle has significant role in controlling hydrogen adsorption-desorption characteristic of decorated multiwalled carbon nanotubes.
Energy and Environment Focus, Mar 1, 2023
In the present study we are reporting dielectric response of strontium titanate (SrTiO3 represent... more In the present study we are reporting dielectric response of strontium titanate (SrTiO3 represented as ST used as filler in 1–5 mwt%)/polycarbonate (PC) nanocomposites of thickness 100 μm synthesized by solution cast method. Polycarbonate serving as passive matrix element and ceramic strontium titanate (SrTiO3) dispersed into polycarbonate to improve effective dielectric response. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Scanning electron microscopy (SEM) have been used to investigate structural, bonding and morphological properties of fabricated nanocomposites respectively. Particular attention has been given on the examination of dielectric response for composites using Impedance analyzer. Dielectric constant has been found to be increased with increasing concentration of SrTiO3 inside the polycarbonate matrix. The observed dielectric constant reaches upto 6.61 for ST5%PC95% composite at 1 KHz. These composites of high dielectric constant can be used as high performance electrode materials for electrical energy storage devices.
Materials Today: Proceedings, 2022
Indian Journal of Pure & Applied Physics, Dec 1, 2007
Thin films of InSb have been obtained by resistive heating method at the pressure 10-5 torr. Mixi... more Thin films of InSb have been obtained by resistive heating method at the pressure 10-5 torr. Mixing of these bilayers has been done by rapid thermal annealing as well as vacuum annealing process. Characterizations of these films have carried out by optical band gap, Rutherford backscattering and X-ray diffraction studies. Obtained results indicate formation of InSb semiconductor.
Journal of Nano-and electronic Physics, 2021
Zinc Sulfide (ZnS) based photocatalytic activity has been focused in solar hydrogen production an... more Zinc Sulfide (ZnS) based photocatalytic activity has been focused in solar hydrogen production and water treatment process because to their very strong redox reaction. Due to wide visible light range, ZnS becomes a promising semiconductor in formation of photocatalysts. The bandgap energies (Eg) of all prepared samples ZnS NCs and MWCNTs/ZnS nanocomposites were evaluated and Methylene Blue (MB) degradation study occurring of ZnS NCs and MWCNTs/ZnS nanocomposites were evaluated under visible light using UV-visible spectroscopy. The author found that removal rate of MB is greater than 95 percentage in the presence of MWCNTs/ZnS composites photocatalysts after 50 min. Crystalline grain size and structure of photocatalyst were characterized by X-ray Diffraction (XRD) spectroscopy. The enhancement of photocatalytic activity can be associated by many factors like a suitable band gap in visible region, crystalline structure of nanocomposites and particle size in nanometer (nm) of the MWCNTs/ZnS nanocomposites. The suitable photocatalytic reaction and mechanisms of MB degradation also included in this article.
2022 8th International Conference on Advanced Computing and Communication Systems (ICACCS), Mar 25, 2022
Macromolecular Symposia, Oct 1, 2021
rGO/Polystyrene composites are prepared via sonication and casting method. In sonication, a mixtu... more rGO/Polystyrene composites are prepared via sonication and casting method. In sonication, a mixture of reduced graphene oxide (rGO) and polystyrene (PS) is mixed together for composite fabrication. The sonication is used to enhance the dispersion of rGO within PS matrix. The XRD spectra show structure of the fabricated composite, Raman spectra confirms orientation of rGO in composites, and SEM results indicate surface morphology of the composites. It has been observed that composites fabricated show a better morphology and dispersion with enhanced stability for hybrid systems like electrodes, batteries, and thermal interface materials.
Advanced Science, Engineering and Medicine, May 1, 2017
2022 International Conference for Advancement in Technology (ICONAT), Jan 21, 2022
In this study, MWCNTs/CdS and MWCNTs/ZnS composites were synthesized by an environmentally friend... more In this study, MWCNTs/CdS and MWCNTs/ZnS composites were synthesized by an environmentally friendly chemical method. The multiwalled carbon nanotubes (MWCNTs) dispersed sulfide composites are used in the treatment of organic pollutants methylene blue (MB) from wastewater with low production cost under visible light. The bandgap study reported that increasing the doping percentage of MWCNTs in sulfides decreases bandgap energy for shift absorbance in the visible region. The visible light activated composite photocatalyst based photocatalytic activity was examined by the removal rate of methylene blue. Methylene blue has degraded in the presence of CdS and ZnS was about 140 minutes, whereas MWCNTs/CdS and MWCNTs/ZnS composites was observed only after about 100 minutes under visible light. It is found that from the study, the order of higher degradation percentage of methylene blue is MWCNTs/CdS > MWCNTs/ZnS > CdS> ZnS. The structure and morphology of the composite material were characterized XRD and SEM, respectively. The photocatalytic properties of composite material were studied by the UV-visible spectroscopy.
international journal of chemical sciences, 2016
Nanodielectric composites have been developed in recent years attempting to improve the dielectri... more Nanodielectric composites have been developed in recent years attempting to improve the dielectric properties such as dielectric properties such as dielectric constant, dielectric strength and voltage endurance. Conventional dielectric material development followed the paths of organic polymers, inorganic ceramics and thin films separately, due to type of capacitors, manufactured, polymeric film and multilayer ceramic capacitors, polymer dielectrics show very high dielectric strength (> 300 kv/mm), lover dielectric losses ( 100) but relative low dielectric strength (< 50 kv/mm) or may be piezoelectric associated with the structure of ceramic. Nanodielectric composites belong to a new type of materials, engineered for improved specific functionality such as better performance in electrical insulation. In the present study, BaCO3 as a filler has been dispersed in polycarbonate in various concentration, Dielectric constant and loss has been measured as a function of frequency.
Materials Today: Proceedings
Science of Advanced Materials
This manuscript presents a study on the photoinduced and gas sensing response of Mn-doped ZnO thi... more This manuscript presents a study on the photoinduced and gas sensing response of Mn-doped ZnO thin films (Zn1−xMnxO, x = 5, 10 mol %) synthesized using the spin coating method. The fabricated thin films were characterized to investigate their structural, bonding, optical, surface morphology, electrical, and gas sensing properties. SEM images displayed a homogeneous surface morphology across the fabricated films with typical grain size ranging from 25 to 30 nm. Optical absorption spectra demonstrated a variation in the optical band gap, ranging from 3.41 eV to 3.87 eV, indicating the tunability of the optical properties with the Mn doping concentration. Photoluminescence (PL) spectra exhibited Near Band Edge emission, as well as blue and green emission peaks, which can be attributed to the presence of defects and impurities in the Mn-doped ZnO thin films. The photoinduced effect was observed through the variation in I–V characteristics due to the excitation of electron-hole pairs, hi...
Materials Today: Proceedings
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Papers by Balram Tripathi