Free-standing, high Li-ion conducting hybrid PAN/PVdF/LiClO4/Li0.5La0.5TiO3 nanocomposite solid polymer electrolytes for all-solid-state batteries

Abstract

The free-standing PAN/PVdF/LiClO4/Li0.5La0.5TiO3 nanocomposite solid polymer electrolytes have been prepared by solution casting technique. The thermal stability of composite solid polymer electrolytes is evaluated by TG/DSC analysis, which reveals that the filler incorporated composite samples exhibit high thermal stability up to 500 °C. The XRD analysis demonstrated that the Li0.5La0.5TiO3 nanoparticles significantly reduced the crystallinity of the hybrid PAN/PVdF/LiClO4 polymer films. The FTIR spectra of PAN/PVdF/LiClO4/Li0.5La0.5TiO3 composites show the vibrational band of –CN stretching, CF2 asymmetric stretching, and Ti-O-La stretching which confirmed the complexation between polymer host matrices and Li0.5La0.5TiO3 nanoparticles. The 10 wt% Li0.5La0.5TiO3 nanoparticles embedded PAN/PVdF/LiClO4 solid polymer electrolyte possessed an excellent ionic conductivity of 1.43 × 10−3 S cm−1 at room temperature, which is far better than the filler-free samples (~ 10−5 S cm−1). The incorporation of Li0.5La0.5TiO3 nanoparticles into the PAN/PVdF/LiClO4 polymer electrolyte improves the concentration of free mobile lithium ions and develops Li-ion conduction channels within the crystalline framework. The PAN/PVdF/LiClO4/Li0.5La0.5TiO3 (10 wt%) composite electrolyte exhibited high thermal stability, good discharge capacities of 122, 105, 94, and 80 mAh g−1 at 0.1, 0.5, 1, and 2C rates, and good cycling stability.