Poly(vinylidene fluoride)-based macroporous separators for supercapacitors

Macroporous polymer separators based on poly(vinylidene fluoride) (PVdF) and several VdF copolymers were prepared by a phase inversion process using acetone as a solvent. The resulting macroporous separators were characterized in terms of morphology, swelling behaviour, thermal and mechanical properties and ionic conductivity. The PVdF separator had a highly porous structure (80%) and exhibited good mechanical properties. Once filled by a molar solution of tetraethylammonium tetrafluoroborate (TEABF4) in acetonitrile (AN) it provided enhanced conductivity (18 mS cm−1 at 25 °C) compared with commercial cellulose and Celgard™ separators.

► Macroporous PVdF based membranes for supercapacitors were prepared via phase inversion method.
► They were studied in terms of electrolyte uptake and of, thermal, mechanical and conductivity behaviors.
► Due to high porosity of the membranes and high crystallinity of PVdF, most of the liquid electrolyte is retained into the porous volume.
► Membrane with higher porosity decreases tortuosity, increases therefore the conductivity.
► Macroporous membranes prepared from PVdF homopolymers exhibited enhanced performances as compared to commercial separators.