Physical and Interfacial Studies on Li0.5La0.5TiO3- Incorporated Poly(ethylene oxide)-Based Electrolytes for All-Solid-State Lithium Batteries

The poly(ethylene oxide)-based hybrid solid polymer electrolytes (HSPE) of different compositions comprising Li0.5La0.5TiO3 (LLTO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) have been prepared by hot-press method. The prepared membranes were characterized by differential scanning calorimetry (DSC), thermogravimetric (TG), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), and tensile analyses. By assembling Li/HSPE/Li symmetric cells, the electrochemical and interfacial properties such as Li+ transference number, lithium dendrite, and compatibility of HSPE with lithium metal were studied at 60 °C. The ionic conductivity measurements revealed that HSPE membrane containing 20% Li0.5La0.5TiO3 exhibited a maximum value of 8.7 × 10–4 S cm–1 at 60 °C. The addition of LLTO as a filler not only enhanced the ionic conductivity and thermal and mechanical stabilities but also improved the electrochemical and interfacial properties appreciably. The enhanced performance of HSPE was attributed to the interaction between the polymeric host and the added filler, which was further confirmed by NMR and FTIR studies.