Browsing by Author "Pritam"

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Dielectric Relaxations and Transport Properties Parameter analysis of novel blended solid polymer electrolyte for Sodium Ion Rechargeable Batteries
(Springer, 2019) Pritam; Arya, Anil; Sharma, Achchhe Lal
A novel blended solid polymer electrolyte comprising polyethylene oxide and polyvinylpyrrolidone polymers for blending and sodium nitrate (NaNO3) as ion conducting species has been optimized via standard solution-cast technique. XRD, FESEM, and FTIR were performed to obtain the information about the structural changes, morphology, and microstructural changes (polymer–ion and ion–ion interactions) of the solid polymer electrolyte films. The electrochemical impedance spectroscopy, linear sweep voltammetry, and i–t characteristics were performed to evaluate the ionic conductivity, voltage stability window, and ion transference number. The impedance study was done in a broad temperature range (40–100 °C). The DSC and TGA were used to obtain information about the thermal transitions and thermal stability of prepared films. The ion dynamics is further investigated by analyzing the complex permittivity, loss tangent, and complex conductivity. All the plots were fitted through established theoretical model/expressions in whole frequency window to obtain dielectric strength, ion conduction path behavior, and relaxation time. Transport parameters such as number density (n), mobility (μ), and diffusion coefficient (D) of mobile ions were obtained by three methods and compared satisfactorily. Lastly, a coherent mechanism for the migration of charge transport carriers within the solid polymer composites has been proposed based on the performed experimental outcome
Dielectric relaxations and transport properties parameter analysis of novel blended solid polymer electrolyte for sodium-ion rechargeable batteries
(Springer New York LLC, 2019) Pritam; Arya A.; Sharma A.L.
A novel blended solid polymer electrolyte comprising polyethylene oxide and polyvinylpyrrolidone polymers for blending and sodium nitrate (NaNO3) as ion conducting species has been optimized via standard solution-cast technique. XRD, FESEM, and FTIR were performed to obtain the information about the structural changes, morphology, and microstructural changes (polymer–ion and ion–ion interactions) of the solid polymer electrolyte films. The electrochemical impedance spectroscopy, linear sweep voltammetry, and i–t characteristics were performed to evaluate the ionic conductivity, voltage stability window, and ion transference number. The impedance study was done in a broad temperature range (40–100 °C). The DSC and TGA were used to obtain information about the thermal transitions and thermal stability of prepared films. The ion dynamics is further investigated by analyzing the complex permittivity, loss tangent, and complex conductivity. All the plots were fitted through established theoretical model/expressions in whole frequency window to obtain dielectric strength, ion conduction path behavior, and relaxation time. Transport parameters such as number density (n), mobility (μ), and diffusion coefficient (D) of mobile ions were obtained by three methods and compared satisfactorily. Lastly, a coherent mechanism for the migration of charge transport carriers within the solid polymer composites has been proposed based on the performed experimental outcome.
Selection of best composition of Na+ ion conducting PEO-PEI blend solid polymer electrolyte based on structural, electrical, and dielectric spectroscopic analysis
(Institute for Ionics, 2019) Pritam; Arya A.; Sharma A.L.
In this paper, we report the investigation on structural, electrical, dielectric properties, and ion dynamics of novel blend polymer electrolyte matrix (PEO-PEI) complexed with sodium hexafluorophosphate salt. All the solid polymer electrolyte films have been synthesized via solution cast method. The SPE films were characterized by the X-ray diffraction, field emission scanning electron microscope, impedance-dielectric spectroscopy, and thermogravimetric analysis. The morphology of the SPE alters with salt addition and confirms the blend polymer complex formation. The FTIR analysis evidenced the complex formation, and increase in the fraction of free ions is achieved. The ionic conductivity exhibits a maximum at the stoichiometric ratio O/Na = 10 and follows the Arrhenius behavior. The fraction of free ions is maximum for the SPE film with the highest ionic conductivity. The optimum electrolyte possesses a voltage stability window of about 4 V, excellent thermal stability up to 380 °C, and high ionic transference number (~ 1). The complex permittivity and conductivity have been simulated in whole frequency window to extract relaxation time and dielectric strength. The dielectric constant and relaxation time exhibited sequentially a maximum and minimum for the SPE film with the highest ionic conductivity. The loss tangent peak shifts toward high frequency with addition of salt, and it infers the faster ion dynamics in the polymer matrix. Then the ion transport parameters number density of charge carriers (n), ion mobility (?), and diffusion coefficient (D) have been obtained by three methods (FTIR, impedance spectroscopy, and loss tangent method) and are in absolute correlation with the impedance results. An ion transport mechanism has been proposed based on experimental findings.