Biopolymer agar-agar doped with NH4SCN as solid polymer electrolyte for electrochemical cell application

A new polymer electrolyte based on the biopolymer Agar-Agar doped with ammonium thiocyanate (NH4SCN) has been prepared and characterized by FTIR analysis, X-ray diffraction measurements, AC impedance spectroscopy, transference number measurements, and DSC analysis. The Fourier transform infrared analysis confirms the complex formation between agar and NH4SCN. The amorphous nature of the polymer electrolyte has been revealed from X-ray diffraction analysis. The highest ionic conductivity has been observed for the sample of composition 1: 1 between Agar and NH4SCN. As a function of temperature, the ionic conductivity of this sample exhibits Arrhenius behavior increasing from 1.03 x 10(-3) S cm(-1) at ambient temperature to 3.16 x 10(-3) S cm(-1) at 343 K. The transference number has been estimated by the dc polarization method, and it has been proven that the conducting species are predominantly cations. Using the highest conductivity polymer electrolyte, solid state electrochemical cell has been fabricated and cell parameters are reported. (C) 2017 Wiley Periodicals, Inc.