A facile preparation of composite polymer electrolyte with high ionic conductivity by thermal treatment

Abstract

Solid polymer electrolyte plays an important part in the development of flexible solid-state lithium ion battery. However, the low ionic conductivity at room temperature limits its practical application. In this article, graphite carbonitride (g-C3N4) was prepared by thermal polymerization method and was blended with polyethylene oxide/lithium perchlorate (PEO/LiClO4) to prepare composite solid polymer electrolyte. X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), optical microscopy (OM), scanning electron microscopy (SEM), differential scanning calorimeter (DSC) and electrochemical workstation were used to characterize the prepared composite solid polymer electrolyte. Results demonstrated that not only the 120 °C annealing and then quenching thermal treatment, but also the interaction among components in composite solid polymer electrolytes could restrict the crystallization of PEO. As a result, the ionic conductivity of composite solid polymer electrolytes at 25 °C could reach to 2.35×10−5 S cm−1, which was three order higher than that of the PEO/LiClO4 polymer electrolyte film.