Study of proton-conducting polymer electrolyte based on K-carrageenan and NH 4 SCN for electrochemical devices

A proton-conducting solid biopolymer electrolyte (SBE) that consists of kappa-carrageenan (K-carrageenan) incorporated with ammonium thiocyanate (NH4SCN) has been prepared by solution-casting technique. The prepared membranes are subjected to XRD, FTIR, and AC impedance analysis to study their structural, optical, and electrical properties of the electrolytes, respectively. The amorphous nature of the membrane has been inferred from the results of XRD analysis. The complexation between salt and host polymer matrix has been confirmed by FTIR. From AC impedance analysis, the polymer incorporated with 0.5% of NH4SCN achieved a maximum ionic conductivity of the order of 6.83 × 10−4 Scm−1. The dielectric spectra and modulus spectra reveal the non-Debye behavior of the polymer membrane. A fuel cell has been constructed using the prepared SBE, and its open circuit voltage has been measured.