High ferroelectric performance of poly (vinylidene difluoride-co-hexafluoropropylene) - based membranes enabled by electrospinning and multilayer lamination

Dielectric materials with ultrahigh energy storage and discharge capabilities have become increasingly vital for high energy efficiency in modern electronics which require immense pulsed power delivery. Ferroelectric polymers offer the benefit of being relatively low-cost, lightweight, and having a lower carbon footprint to produce and maintain in comparison to ceramics. Electrospinning polyvinylidene difluoride (PVDF) nanofibres have proven to produce a highly polarised polymorph, although dielectrics involving these alone often have problems with leakage currents. In this work, multilayer all-polymer laminates were assembled by alternative stacking of poly (methyl methacrylate) (PMMA) thin films and electrospun poly (vinylidene difluoride-co-hexafluoropropylene) (PVDF-co-HFP) membranes, where the nonwoven PVDF-co-HFP nanofibrous membranes were electrospun with an ionic liquid (1-allyl-3-methylimidazolium chloride (AMIM) to eliminate leakage currents and maximize the discharged energy density. The effects of the crystallography, microstructures and interfaces of the multilayer PMMA/PVDF-co-HFP laminates on the energy storage capacity were discussed. • Electrospinning PVDF-co-HFP nanofibers enhance the electroactive crystal β-phase. • Adding an ionic liquid (AMIM) to PVDF-HFP gives the greatest proportion of β-phase. • Hot pressed layered laminates of PMMA:PVFHA keep a fibrous structure up to 160 °C. • Ferroelectric testing of laminates shows sample homogeneity is key to achieving high U e .