ZnFe2O4 nanoparticles assisted ion transport behavior in a sodium ion conducting polymer electrolyte

This paper reports ZnFe2O4 nanoparticles as a promising dispersoid for a polymer electrolyte system with superior electrochemical properties. The effect of ZnFe2O4 nanoparticles on the physiochemical, electrochemical, and ion dynamic properties of a polymer electrolyte system comprising polyethylene oxide (PEO), sodium triflate (NaCF3SO3), and propylene carbonate (PC) has been studied. ZnFe2O4 prepared by citrate combustion method shows a particle size below 50 nm. The molecular interactions and surface morphology of the electrolyte films have been investigated using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Significant reduction in the crystallinity of the polymer electrolyte system is observed on dispersion of ZnFe2O4 nanoparticles. The electrolyte film with 0.5 wt.% of ZnFe2O4 displays the highest ionic conductivity of 6 × 10−5 S cm−1 at room temperature and electrochemical stability of 4.0 V with superior Na+ transference number of 0.36. The ZnFe2O4 nanoparticles dissociate ions and promote translational motion of the ions within the electrolyte system.