Preparation of LAGP/P(VDF-HFP) polymer electrolytes for Li-ion batteries

Abstract

LAGP (Li_1.5Al_0.5Ge_1.5(PO₄)₃) as a lithium ion conducting filler, was added into P(VDF-HFP) based gel polymer electrolytes to study its effects on the morphology, structure, ionic conductivity and battery performances. The composite membranes show an enormous number of micropores, and exhibit high swelling when activated with liquid electrolyte. The addition of a glass ceramic filler increases the amorphous phase of the polymer by acting as facile gel centers and enhances the ionic conductivity. The electrochemical stability window is up to 5.0 V versus Li⁺/Li. The discharge capacity of cells assembled with LAGP/P(VDF-HFP) membranes reaches 169 mA h g⁻¹ and retains over 96% of its initial capacity after 100 cycles, and its rate performance improves after the addition of LAGP. The results indicate that the LAGP/P(VDF-HFP) composite materials can be developed as excellent polymer electrolyte membrane for lithium ion batteries.