Archana Chandra

Synthesis, characterization and ion transport properties of hot-pressed solid polymer electrolytes (1−x) PEO:x KI

Synthesis and ion transport properties of hot-pressed solid polymer electrolytes (SPEs), (1−x) PEO: x KI, where x is the content of KI in wt%, are reported. A hot-press technique has been used for the formation of the polymeric membranes in place of the usual solution cast method. The composition (80 PEO:20 KI) was identified as the highest conducting polymer electrolyte on the basis of compositional dependent conductivity studies of PEO:KI films. A conductivity enhancement of more than two orders of magnitude from that of the pure PEO was achieved. Materials characterization and ion transport mechanism were explained by using various experimental techniques.

Ionic Mobility, Drift Velocity, and Dielectric Studies on Ag + Ion Conducting Glassy Electrolytes

Ionic mobility (μ), ionic drift velocity (v_d), and dielectric measurements of new Ag^+ ion conducting glassy systems: x[0.75AgI: 0.25AgC1]: (1 - x)[Ag_2O: V_2O_5], where 0:1 ＜ x ＜ 1 in molar weight fraction, are reported. The present glassy electrolytes have been synthesized by the melt-quench technique using a high-speed twin roller-quencher. An alternate host salt: ’quenched [0.75AgI: 0.25AgC1] mixed system/solid solution’ has been used in place of the traditional host AgI. The compositional dependence conductivity studies on the glassy systems indicated that the composition 0.8[0.75AgI: 0.25AgC1]: 0.2[Ag_2O: V_2O_5] shows the highest conductivity (σ ~ 9.0 × 10^(-3) S/cm) at room temperature. Some other basic ion transport parameters, viz. the mobile ion concentration (n) and ion transference number (t_(ion)), have also been characterized using different experimental techniques.

Dielectric study of hot-pressed nanocomposite polymer electrolytes

Ion-conducting nanocomposite polymer electrolyte films based on poly(ethylene oxide)-NaPO3 3: 1 with up to 15 wt % of SiO2 have been prepared using recently developed hot-press technique instead of conventional solution cast method. With 7 wt % of SiO2, the film conductivity has been enhanced by an order of magnitude. The materials have been characterized by Fourier transform infrared spectrometry and thermogravimetric analysis. For the composition with the highest conductivity, the temperature dependences of ionic mobility, mobile ions concentration, ionic transference number, and ionic drift velocity have been determined. Dielectric constant and dielectric loss have been measured. The conductivity enhancement has been discussed on the basis of existing theories of dielectrics.

Ionic Drift Velocity Measurements on A Nano‐composite Polymer Electrolyte: 95[90PEO: 10AgNO3]: 5SiO2

Ionic drift velocity (vd) measurements on a hot‐press synthesized nano‐composite polymer electrolyte (NCPE) membrane: 95[90PEO: 10AgNO3]: 5SiO2, are reported. The ionic transference number (tion) values were determined using dc polarization Transient Ionic Current (TIC) technique for vd measurement at different temperatures. The drift energy (Ed), involved in the thermally activated process was determined from the temperature dependent studies on ionic drift velocity using the log vd vs 1/T Arrhenius plot. At all the temperatures, the ionic drift velocity is directly proportional to the ionic mobility (μ) at a fixed value of applied dc potential.

Temperature dependent ionic conductivity and mobility studies of hot-pressed solid polymer electrolytes

Temperature dependent ionic conductivity (σ), ionic mobility (µ), and mobile ion concentration (n) of the hot-pressed Solid Polymer Electrolytes (SPEs): (1-x) PEO: x NaBr, where 0 < x < 50 in wt. %, has been reported. SPE films have been casted using a hot-press technique in place of the traditional solution cast method. A conductivity enhancement of the two orders of magnitude was achieved in SPE film composition: (70PEO: 30NaBr) at room temperature and this has been referred to as Optimum Conducting Composition (OCC). To determine the activation energy (Ea), energy of migration (Em) and energy of formation (Ef) temperature dependent studies of SPE OCC have been carried out with the help of various experimental procedures.

Synthesis and Characterization of Hot-Pressed Solid Polymer Electrolytes

Synthesis and ion transport characterizations on hot-pressed solid polymer electrolytes (SPEs): (1-x) PEO: x KBrO 3, where x in wt. (%), are reported. The compositional (x) dependent conductivity (σ) studies revealed SPE film: (70PEO: 30KBrO 3) as the Optimum Conducting Composition (OCC) with room temperature conductivity σ ~ 4.36 × 10 -7 Scm -1 , which is more than two orders of magnitude higher than that of pure PEO. To understand the ion transport behavior in SPE films, the measurement on some basic ionic parameters viz. ionic conductivity (σ), ionic mobility (μ) and mobile ion concentration (n) have been carried out using different experimental techniques. Material characterizations were done with the help of XRD, SEM, DSC and TGA techniques. The activation energies (E a

Ion Transport Properties of Hot-Pressed Solid Polymer Electrolytes: (1-x) PEO: x NaHCO3

Ion transport properties of hot-pressed Solid Polymer Electrolyte (SPE) membranes: (1-x) PEO: x NaHCO3, where x = 0 – 50 wt. (%), has been reported. SPE films have been casted using a hot-press technique in place of the traditional solution cast method. A conductivity enhancement of the two orders of magnitude was achieved in SPE film: 70PEO: 30NaHCO3 and this composition has been referred to as Optimum Conducting Composition (OCC). Materials characterization was done with the help of FTIR and DSC techniques. The ion transport behavior in SPE membranes have been discussed on the basis of experimental measurements on their ionic conductivity ( ) and other parameters. The temperature dependent conductivity studies have also been done to compute the activation energy (Ea) values by least square linear fitting of ‘log – 1/T’ Arrhenius plots.