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,
