Structure and electrochemical properties of composite polymer electrolyte based on poly vinylidene fluoride–hexafluoropropylene/titania–poly(methyl methacrylate) for lithium-ion batteries

Abstract

Titania–poly(methyl methacrylate) (PMMA) organic–inorganic hybrid material is synthesized via in situ polymerization. The hybrid material is employed to prepare poly vinylidene fluoride–hexafluoropropylene (PVdF–HFP) composite polymer electrolyte. The effect of the hybrid material is investigated by SEM, TG-DSC, AC impedance and charge/discharge cycling tests. The results demonstrate that the inorganic–organic hybrid material as additive increases the porosity, pore size and electrolyte uptake of the PVdF–HFP composite polymer electrolyte membrane, so that the ionic conductivity of the composite polymer electrolyte membrane is improved. The performance enhancement of the composite polymer electrolyte is confirmed by an electrochemical test using LiCoO2/Li cells in the voltage range of 2.75–4.4 V. This study shows that titania–PMMA hybrid material is a promising additive for PVDF–HFP composite polymer electrolyte for Li-ion batteries.