Novel composite corn starch-graphene oxide-based polymer electrolyte with the addition of cerium nitrate to improve its ionic conductivity

Abstract

Solid polymer electrolytes (SPE) offer a safer alternative to liquid electrolytes in electrochemical applications, driving interest in enhancing their ionic conductivity. This study examined the impact of adding cerium nitrate (Ce(NO₃)₃) to a composite SPE to boost conductivity. SPEs were synthesized from corn starch, Ce(NO₃)₃ salt, and graphene oxide (GO) via solution casting, using Ce(NO₃)₃ variations of 0%, 2.5%, 5%, 7%, and 9%. X-ray diffraction (XRD) analysis indicated a structural shift toward amorphousness with increasing salt, which enhances ionic mobility. Fourier transform infrared (FTIR) analysis revealed narrowing of the O-H peak with starch and GO, implying hydrogen bonding that promotes an amorphous phase. At the CH₂OH peak, salt addition suggested interaction with starch. Scanning electron microscopy (SEM) showed a porous composite morphology conducive to ion movement. Thermogravimetric analysis (TGA) confirmed good thermal stability. Electrochemical impedance spectrometry (EIS) results showed an increase in ionic conductivity in SPE due to the addition of Ce(NO₃)₃ with the highest conductivity value observed at the 9% variation, reaching 39 times higher than those without Ce(NO₃)₃. This study highlights significant improvements in ionic conductivity by incorporating Ce(NO₃)₃ into SPE, enhancing the energy storage system’s performance. The research offers valuable insights into developing advanced SPE materials with superior electrochemical properties for further exploration and innovation in the field of electrochemical devices.