Study on ionic conductivity, dielectric and electrochemical properties of solid polymer electrolyte for battery applications

A novel solid polymer electrolyte (SPE) comprising of corn starch (CS) and sodium iodate (NaIO 3 ) as ion-conducting species were prepared by using the solution casting technique. Electrochemical impedance spectroscopy (EIS) was performed to obtain information about the conductivity and dielectric studies of the polymer-salt complex. It was found that the sample with 3 wt% of NaIO 3 has achieved the maximum conductivity with a value of 1.08 × 10 −4 Scm −1 at ambient temperature. Dielectric and modulus studies were carried out to better understand the conductivity behaviour of the SPE samples. From results, it shows that non-Debye type of CS-NaIO 3 SPE. It is observed that the dielectric constant ( ɛ r ) increases sharply towards the lower frequencies due to electrode polarization effect. On the other hand, the peaks observed for imaginary of the modulus ( M i ) are due to conductivity relaxation which shows the material is ionic conductors. An electrochemical cell fabricated using the highest ionic conduction of SPE films produced an open voltage of 1.51 V and an increased discharge time is seen with the decrease of current given. The results highlight the prepared SPE film has the ability to improve the performance of a primary sodium-ion battery in a safe mode.