Ion transport and battery discharge characteristics of polymer electrolyte based on PEO complexed with NaFeF4 salt

Ion-conducting solvent-free solid polymer electrolytes based on polyethylene oxide (PEO) complexed with sodium ferric tetrafluoride (NaFeF4) were prepared using a solution casting technique. The complexation of the films was investigated through X-ray diffraction and Fourier transform infrared spectroscopic studies. Measurements of DC conductivity in the temperature range 300–370 K and the transference numbers were carried out to investigate the nature of charge transport in the polymer electrolyte system. Transference number data shows that the charge transport in this system is found to be predominantly due to ions. Using these polymer electrolytes, electrochemical cells were fabricated with the configuration of Na/(PEO+NaFeF4)/(I2+C+electrolyte). Various cell parameters, such as open circuit voltage, short circuit current, power density, and energy density of the device were evaluated and reported.