High electrochemical performance of nano TiO2 ceramic filler incorporated PVC-PEMA composite gel polymer electrolyte for Li-ion battery applications

The Gel polymer electrolytes (GPE) exhibit promising performance in the application of Li-ion batteries due to their high ionic conductivity and appreciable Li+ ion transference number. However, the poor interfacial stability between GPE and metallic Li electrode results in undesirable electrochemical performance, which may lead to safety hazards. Herein, we report the fabrication of nanocomposite polymer electrolyte (NCPE) based on PVC (5)-PEMA (25)-EC/DMC (67)-LiClO4 (8) incorporated with hydrothermally derived TiO2 spherical nanoparticles (NPs) as ceramic filler to overcome the above critical issue. The effects of TiO2 NPs on GPEs were systematically investigated by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) thermogravimetric analysis (TGA) and electrochemical analysis. Notably, 5 wt% TiO2 in NCPE remarkably enhanced the ionic conductivity and interfacial properties with metallic Li anode. Besides, 5 wt% TiO2 in NCPE exhibited improved thermal and electrochemical stability with high Li + ion transference number, all of which are superior to ceramic free GPE. The excellent electrochemical performance can be ascribed to the dispersion of TiO2 spherical NPs, which facilitates the charge carriers and hinders local reorganization of the polymer chains. As a result, the amorphous phase of polymer host can significantly improve, increasing the transportation of Li cation in NCPE. Thus, 5 wt% TiO2 spherical NPs incorporated NCPE is a promising reliable polymer electrolyte cum separator for Li-ion battery applications.