Computational Nanoionics Research Laboratory

Bhilai, India

Computational Nanoionics Research Laboratory

Bhilai, India
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Verma M.L.,Computational Nanoionics Research Laboratory | Sahu H.D.,Computational Nanoionics Research Laboratory
Ionics | Year: 2017

The ionic conductivity and dielectric properties of the solid nanocomposite polymer electrolytes formed by dispersing a low particle-sized TiO2 ceramic filler in a poly (ethylene oxide) (PEO)-AgNO3 matrix are presented and discussed. The solid nanocomposite polymer electrolytes are prepared by hot press method. The optimum conducting solid polymer electrolyte of polymer PEO and salt AgNO3 is used as host matrix and TiO2 as filler. From the filler concentration-dependent conductivity study, the maximum ionic conductivity at room temperature is obtained for 10 wt% of TiO2. The real part of impedance (Z′) and imaginary part of impedance (Z″) are analyzed using an LCR meter. The dielectric properties of the highest conducting solid polymer electrolyte are analyzed using dielectric permittivity (ε′), dielectric loss (ε″), loss tangent (tan δ), real part of the electric modulus (M′), and imaginary part of the electric modulus (M″). It is observed that the dielectric constant (ε′) increases sharply towards the lower frequencies due to the electrode polarization effect. The maxima of the loss tangent (tan δ) shift towards higher frequencies with increasing temperature. The peaks observed in the imaginary part of the electric modulus (M″) due to conductivity relaxation shows that the material is ionic conductor. The enhancement in ionic conductivity is observed when nanosized TiO2 is added into the solid polymer electrolyte. © 2017 Springer-Verlag Berlin Heidelberg


Verma M.L.,Computational Nanoionics Research Laboratory | Rao B.K.,Computational Nanoionics Research Laboratory | Singh R.,Uday Prasad Government Polytechnic | Banchor D.,Computational Nanoionics Research Laboratory | Sahu H.D.,Computational Nanoionics Research Laboratory
Ionics | Year: 2017

Mechanical strength is one of the significant properties of any solid polymer electrolyte of electrochemical devices, therefore; the ab initio study based on density functional theory is performed, and the bond strength of Poly ethylene oxide (PEO)5 polymer without and with Lithium Perchlorate (LiClO4) is investigated. The central oxygen atom of PEO is displaced till to respective bond is broken along X, Y, and Z directions, respectively. The same is simulated in the presence of LiClO4 and the minimum bond breaking energy which is also called the mechanical strength is calculated along three directions. Higher energy is required in compression of (PEO)5 along x and y axes than expansion, and vice versa along z axis. The same is observed for (PEO)5-LiClO4 polymer electrolyte along x and y axes, along z direction; the energy required is nearly same for compression/expansion. Due to this energy, crystalline nature of a polymer is reduced and amorphous nature is increased. In DOS analysis, the forbidden energy gap of (PEO)5-LiClO4 is reduced by 1.0 eV than (PEO)5; it causes to increase the lithium cation concentration and the ionic conductivity. © 2017 Springer-Verlag Berlin Heidelberg


Upma,Computational Nanoionics Research Laboratory | Verma M.L.,Computational Nanoionics Research Laboratory | Verma D.,Computational Nanoionics Research Laboratory
Ionics | Year: 2017

The electronic and chemical bonding properties of biomaterial potato starch within the density functional theory are presented in this paper, with the aim to be used in electrochemical devices and biomedical applications. In the density of states and projected density of states analysis, the energy difference between the highest occupied molecular orbital and lowest unoccupied molecular orbital is reduced by 2.9 eV, which exhibits the semi-conducting behaviour of modified potato starch in the presence of NaI salt. Calculated charge density predicts the bonding properties and crystal orbital overlap population analysis exhibits the increase of amorphous nature and ionic conductivity due to sodium ion concentration. In this theoretical study, different behaviours of modified potato starch are clearly seen in the presence of NaI salt. © 2017 Springer-Verlag GmbH Germany


Singh N.K.,Shri Shankaracharya Institute of Engineering and Technology | Verma M.L.,Computational Nanoionics Research Laboratory | Minakshi M.,Murdoch University
Bulletin of Materials Science | Year: 2015

Physical and electrochemical properties of polyethylene oxide (PEO)-based nanocomposite solid polymer electrolytes (NPEs) were investigated for symmetric capacitor applications. Nanosize fillers, i.e., Al2O3 and SiO2 incorporated polymer electrolyte exhibited higher ionic conductivity than those with filler-free composites. The composites have been synthesized by the completely dry (solution-free) hot-press method. The addition of filler in fractional amount to the solid polymermatrix at room temperature further enhances the ionic conductivity. Nature of the NPEs were studied using X-ray diffraction and energy-dispersive spectra analyses. Thermal stability of the resulting electrolyte was analysed by thermogravimetric analysis and differential scanning calorimetric studies. Morphology changes occurred during the addition of fillers was evidenced by scanning electronic microscope images. Solid polymer electrolytes exhibiting these parameters was found to be suitable for solid state capacitors. The results obtained from the electrolytes with an optimum compositions (PEO70AgI30)93(Al2O3)7 and (PEO70AgI30)95(SiO2)5 used in the (PEO70AgI30)70(AC)30 electrodes for symmetric capacitor applications and their performances were analysed by impedance spectroscopic, Bode plot, cyclic voltammetry, discharge characteristics and leakage current profile. © Indian Academy of Sciences.


Choudhary A.,Government V Y T Pg Autonomous College | Sahu Y.K.,Government V Y T Pg Autonomous College | Oudhia A.,Computational Nanoionics Research Laboratory | Verma M.L.,Government V Y T Pg Autonomous College
Advanced Science Letters | Year: 2015

Here we present an ab-initio study of structural and electronic properties of ZnO molecules optimized in two different geometries viz. 3D ZnO-Cage Like structure and a planer ZnO nanoribbon (ZNR) structure. The whole environment was set in local density approximation correlation function (LDA) under density functional theory (DFT). A noticeable difference in the band gap and consequent electronic properties of the ZnO-Cage like structure with respect to ZNR is observed. The study reveals new possibilities for the fabrication of ZnO nanostructures with controlled electronic properties through shape dependent structural reconstructions. © 2015 American Scientific Publishers. All rights reserved.


Rao B.K.,Computational Nanoionics Research Laboratory | Verma M.L.,Computational Nanoionics Research Laboratory
Ionics | Year: 2015

The analysis of ionic mobility of Ag+ ions in the nano-composite material is performed. The material is space charge polarized initially by applying a dc field ~0.5 V. The depolarization potential is recorded at various isothermal conditions in the temperature range of 300–535 K. By considering open circuit condition, drift and trapped ionic mobility are analyzed and the results are compared with the ionic mobility measured by conventional transient ionic current (TIC) and experimental techniques in the same temperature range. © 2014, Springer-Verlag Berlin Heidelberg.


Rao B.K.,Computational Nanoionics Research Laboratory | Verma M.L.,Computational Nanoionics Research Laboratory
Chemical Physics | Year: 2016

Inclusion of the space charge depolarization in the model to calculate transport properties of a nano-composite material is investigated. Specifically, the effect of diffusion current density; displacement current density; ohmic current density and excess charge current density are included under an open circuit condition. The proposed model takes into account of the excess charge produced during the space charge polarization, and may be applied to any ionic material. © 2016 Elsevier B.V.


Verma M.L.,Computational Nanoionics Research Laboratory | Sahu H.D.,Computational Nanoionics Research Laboratory
Ionics | Year: 2015

Solid nanocomposite polymer electrolytes based on polyethylene oxide (PEO), AgNO3 as salt, and nanosized Fe2O3 (less than 50 nm size) as filler are prepared by hot press method. In (100-x) PEO:xAgNO3 system (where x = 5 ≤ x ≤ 50 wt%), the solid polymer electrolyte 90PEO:10AgNO3 gives highest ionic conductivity. This composition is further used as host matrix and Fe2O3 as filler for the preparation of solid nanocomposite polymer electrolytes (100-x) (90PEO:10AgNO3):xFe2O3 (where x = 5 ≤ x ≤ 30 wt%). The real impedance (Z') and imaginary impedance (Z") of the samples are analysed using LCR meter. The maximum ionic conductivity is observed for 10 wt% of filler Fe2O3. The optimum conducting composition 90(90PEO:10AgNO3):10Fe2O3 is used for further study. The dielectric response of the samples is analysed using dielectric constant (ε'), dielectric loss (ε"), loss tangent (tanδ), and real and imaginary part of electric modulus (M' and M"). The ionic conductivity and dielectric response of the solid nanocomposite polymer electrolytes are studied within the frequency range of 100 Hz–5 MHz and within the temperature range of 300–323 K. It is observed that the dielectric constant rises sharply towards low frequencies due to electrode polarization effects. The maxima of the loss tangent (tan δ) shift towards higher frequencies with increasing temperature. The enhancement in ionic conductivity is observed when nanosized Fe2O3 filler is added into the solid polymer electrolyte. © 2015, Springer-Verlag Berlin Heidelberg.

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