• N NALLAMUTHU

Articles written in Bulletin of Materials Science

• Promising biodegradable polymer blend electrolytes based on cornstarch:PVP for electrochemical cell applications

Higher proton conducting polymer blend electrolytes (HPCPBEs) of cornstarch: poly vinyl pyrrolidone (PVP):ammonium thiocyanate (NH$_4$SCN) have been prepared by solution casting technique. Enhancement of amorphousnature of the polymer blend electrolytes have confirmed by X-ray diffraction analysis. The presence of functional groups in Fourier transform infrared spectrum shows the complexation between salt and host polymer matrix. At ambient temperature, 70 wt% NH$_4$SCN mixed composition has obtained the maximum conductivity ($1.36 \times 10^{–4}$ S cm$^{–1}$). The dielectric properties of the prepared samples have been analysed. The dielectric spectra and modulus spectra reveal the non-Debye behaviour of the polymer electrolytes. Low activation energy (0.14 eV) with regression value of 0.98 has been revealed from temperature dependence of ionic conductivity studies. Wagner’s polarization technique is used to confirm the conductivity due to the ions. Electrochemical behaviour of HPCPBE has been analysed by cyclic voltammetry. Anelectrochemical cell has fabricated using the HPCPBE and the observed open circuit voltage is 1.15 V.

• Structural and electrical behaviours of amino acid-based solid polymer electrolytes

Sodium-ion conduction-based blend polymer films have been developed with the incorporation of amino acid and L-phenylalanine for electrochemical storage device applications. The X-ray diffraction and Fourier transform infrared spectroscopy techniques are used to characterize the structural identification, which concerns enhancing the ionic movement and the existence of ions in blended polymer with the interaction of amino acid and salt. Variations in asymmetrical and symmetrical stretching vibrations of ions were investigated by the appeared partition peaks of FTIR in absorbance mode. Electrical impedance analysis has explained the microstructural properties of polymers through the complex impedance spectra. The enhanced electrical conductivity of 2.56 910$^{-5}$ S cm$^{-1}$ has been identified for 2.5 wt% of L-phenylalanine added blend polymer electrolyte system at ambient temperature. From the frequency dependence conductivity analysis, ${\sigma}_{dc}$ values are calculated from Jonscher’s power law. In temperature-dependent conductivity analysis, two different types of activation energies are obtained for lower and higher temperatures. The dielectric and loss tangent analyses are also calculated and analysed the relaxation process based on the hopping mechanism. The electrochemical stability of higher conductivity solid polymer electrolytes is also verified by cyclic voltammetric analysis.

• # Bulletin of Materials Science

Volume 45, 2022
All articles
Continuous Article Publishing mode

• # Dr Shanti Swarup Bhatnagar for Science and Technology

Posted on October 12, 2020

Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020