Department Of Physics
Permanent URI for this communityhttps://kr.cup.edu.in/handle/32116/57
Browse
6 results
Search Results
Item Effect of variation of different nanofillers on structural, electrical, dielectric, and transport properties of blend polymer nanocomposites(Institute for Ionics, 2018) Arya,Anil; Sadiq, Mohd; Sharma, A.L.In the present work, the effect of various nanofillers with different particle sizes and dielectric constants (BaTiO3, CeO2, Er2O3, or TiO2) on blend solid polymer electrolyte comprising PEO and PVC complexed with bulky LiPF6 has been explored. The XRD analysis confirms the polymer nanocomposite formation. FTIR provides evidence of interaction among the functional groups of the polymer with the ions and the nanofiller in terms of shifting and change of the peak profile. The highest ionic conductivity is ~ 2.3 x10−55 S cm−1 with a wide electrochemical stability window of f ~ 3.5 V for 10 wt% Er2O3. The real and imaginary parts of dielectric permittivity follow the identical trend of the decreasing value of dielectric permittivity and dielectric loss with increase in the frequency. The particle size and the dielectric constant show an abnormal trend with different nanofillers. The AC conductivity follows the universal Jonscher power law, and an effective mechanism has been proposed to understand the nanofiller interaction with cation coordinated polymer.Item Structural, electrical properties and dielectric relaxations in Na+-ion-conducting solid polymer electrolyte(Institute of Physics Publishing, 2018) Arya, A.; Sharma, A.L.In this paper, we have studied the structural, microstructural, electrical, dielectric properties and ion dynamics of a sodium-ion-conducting solid polymer electrolyte film comprising PEO8-NaPF6+ x wt. % succinonitrile. The structural and surface morphology properties have been investigated, respectively using x-ray diffraction and field emission scanning electron microscopy. The complex formation was examined using Fourier transform infrared spectroscopy, and the fraction of free anions/ion pairs obtained via deconvolution. The complex dielectric permittivity and loss tangent has been analyzed across the whole frequency window, and enables us to estimate the DC conductivity, dielectric strength, double layer capacitance and relaxation time. The presence of relaxing dipoles was determined by the addition of succinonitrile (wt./wt.) and the peak shift towards high frequency indicates the decrease of relaxation time. Further, relations among various relaxation times () have been elucidated. The complex conductivity has been examined across the whole frequency window; it obeys the Universal Power Law, and displays strong dependency on succinonitrile content. The sigma representation () was introduced in order to explore the ion dynamics by highlighting the dispersion region in the Cole-Cole plot () in the lower frequency window; increase in the semicircle radius indicates a decrease of relaxation time. This observation is accompanied by enhancement in ionic conductivity and faster ion transport. A convincing, logical scheme to justify the experimental data has been proposed. ? 2018 IOP Publishing Ltd.Item Role of low salt concentration on electrical conductivity in blend polymeric films(Integrated Science, 2016) Arya, Anil; Sharma, Sweety; Sadiq, Mohd; Sharma, A. L.A new blend polymer electrolyte based on polyethyelene oxide (PEO) and polyacrylonitrile (PAN) doped with Lithium Hexafluorophosphate (LiPF6) has been prepared by solution casting technique using Dimethyalformamide (DMF) as solvent. The prepared samples were characterized by FTIR, FESEM and ac impedance spectroscopic measurements. The complex formation between blend polymer (0.5g PEO: 0.5g PAN) and LiPF6 has been studied using Fourier transform infrared spectroscopy (FTIR). From AC impedance spectroscopic analysis there is enhancement of two order on addition of salt than pure PEO-PAN. The effect of low salt concentration on the conductivity and surface morphology of the blend polymer electrolyte has been discussed.Item Optimization of Free standing Polymer Electrolytes films for Lithium ion batteries application(Integrated Science, 2016) Sadiq, M.; Arya, Anil; Sharma, A. L.The free standing polymer nancomposite films consisting of blend polymer based on Poly(acrylonitrile) (PAN) as host polymer–Poly(ethylene oxide)(PEO) as a copolymer, Dimethylformamide (DMF) as solvent and Lithium hexaflourophosphate (LIPF6) as a conducting speciesm were prepared. Keeping in view of characterization of solid state film such as, Fourier transform infrared (FTIR) spectroscopy is done for an understanding of the microscopic interaction among the different component present in the material system. The energy storage/conversion device applications have been analyzed by the impedances spectroscopy. The surface morphology or micro-structural of the polymer nanocomposite electrolytes film was analyzed by FESEM. The electrochemical stability window was about ~4V for the polymer electrolyte film at (/Li=6). The advantageous outcome of PAN combining with PEO based electrolytes is in comparable electrical conductivity and wider electrochemical stability window. Further optimization might lead to practical solid state polymer electrolytes for lithium ion batteries.Item Polymer electrolytes for lithium ion batteries: a critical study(Institute for Ionics, 2017) Arya, A.; Sharma, A. L.Polymer electrolytes (PEs) are an essential component being used in most energy storage/conversion devices. The present review article on a brief history, advantage, and their brief application of polymer electrolyte systems. It consists of a glimpse on liquid, gel, and solid polymer electrolyte and a contrast comparison concerning benefits/disadvantages among the three. The article started with a brief introduction of polymer electrolytes followed by their varieties and extreme uses. The role of host polymer matrix by taking numerous examples of polymer electrolyte published by the different renowned group of the concerned field has been explored. The criteria for selection of appropriate host polymer, salt, inorganic filler/clay, and aprotic solvents to be used in polymer electrolyte have been discussed in detail. The mostly used polymer, salt, solvents, and inorganic filler/clay list has been prepared in order to keep the data bank at one place for new researchers. This article comprises different methodologies for the preparation of polymer electrolyte films. The different self-proposed mechanisms (like VTF, WLF, free volume theory, dispersed/intercalated mechanisms, etc.) have been discussed in order to explain the lithium ion conduction in polymer electrolyte systems. A numerous characterization techniques and their resulting analysis have been summarized from the different published reports at one place for better awareness of the scientific community/reader of the area. ? 2017, Springer-Verlag Berlin Heidelberg.Item Electrical Conductivity and Ion Transport Number Analysis of Polymer Nanocomposite Films(The Research Publication, 2016) Sharma, Parul Kumar; Sharma, Anshu Kumar; Sadiq, M.; Sharma, A. L.Solid state free standing polymer nanocomposite films have been used in numerous vitality related segments like: high energy density solid polymer batteries, PEM fuel cells, super capacitors, etc. Such applications require a desirable conductivity value of the order of ~10-3 Scm-1at room temperature. A free standing transparent film of solid state polymer electrolyte based on PEO+ LiPF6 with different compositions of nano sized filler (BaTiO3) in weight percent (x = 0, 1, 2, 5, 10, 15, 20 ) is synthesized by using standard solution cast technique. Surface morphology of the prepared polymer composition is examined by field emission scanning electron microscopy (FESEM). I-V characteristics of the prepared sample have been characterized for the stability of electrochemical potential window. The transport number analysis of prepared sample has been done to separate out the contribution due to ions and electrons in the electrical conductivity results. The transference number has been estimated and found of the order of ~94%.