Study Of Phase - Separation Pvdf - Polymer Blend Gelled With Ionic-Liquid For Lithium Rechargeable Battery

Abstract

PVDF-polymer blend membranes were successfully prepared by using the phase- separation method. PVDF/PMMA denoted as System 1 and PVDF/PEMA denoted as System 2 membranes were added with salicylic acid as a foaming agent to produce a porous structure within the polymer blend matrices. An ionic-liquid mixture of 1-ethyl-3 methyl imidazolium trifluoromethanysulfonyl imide (EMITFSI) and lithium bis-trifluoromethylsulfonyl imide (LiTFSI) was used to activate the PVDF- polymer membranes. From the scanning electron microscope image, the PVDF- polymer blend membrane showed a porous structure, which leads to a high electrolyte uptake. For System 1, sample S1-E90 exhibited a high ionic conductivity -4 -1 of 3.10 × 10 S cm at room temperature, high lithium-ion transference number (0.7922) and wide electrochemical stability window (4.3 V). For System 2, the ionic conductivity of sample S2-E70 was 1.26 × 10 -4 -1 S cm at 303 K. Electrochemical stability window for this sample was 5.1 V and the lithium ion transference number was 0.6952. All membranes were characterized by using different types of instruments including; X-ray diffraction, Fourier-transform infrared spectroscopy,