Lithium ion conducting PVA:PVdF polymer electrolytes doped with nano SiO2 and TiO2 filler

• PVA:PVdF:LiCF3SO3:SiO2 Vs PVA:PVdF:LiCF3SO3:TiO2 composite polymer electrolyte.
• Compared two system: 80PVA:20PVdF:15LiCF3SO3:4TiO2 is best for Li-ion battery.
• It possess maximum ionic conductivity of 3.7×10−3 S cm−1 at 303 K.
• Composite system have wide electrochemical stability window than filler free system.
• TiO2 system: High Tensile strength-22.6 MPa and good thermal stability-260 °C.

The effect of nano SiO2 and TiO2 fillers on the thermal, mechanical and electrochemical properties of PVA:PVdF:LiCF3SO3 have been investigated by three optimized systems of SPE (80PVA:20PVdF:15LiCF3SO3), CPE-I (SPE:8SiO2) and CPE-II (SPE:4TiO2). From the TGA curve least weight loss has been observed for CPE-II indicating high thermal stability compared to other systems. Stress–strain curve of the prepared samples confirm the enhancement of tensile strength in CPE-II compared to CPE-I and SPE. Conductivity studies show that addition of TiO2 filler slightly enhances ionic conductivity 3.7×10−3 S cm−1 compared to filler free system at 303 K. Dielectric plots have been analyzed and CPE-II possesses higher dielectric constant compared to CPE-I and filler free system. Temperature dependence of modulus plots has been studied for highest conductivity possessing sample. Wider electrochemical stability has been obtained for nano-composite polymer electrolytes. The results conclude that the prepared CPE-II shows the best performance and it will be well suited for lithium ion batteries.