Triptycene improved crystallization characteristics and boosted energy density in PVDF-based all-organic composites

Abstract

Polymer composites with high breakdown strength and low loss have potential applications in dielectric films because of their excellent energy-storage performance. However, the inorganic fillers always decrease the breakdown strength, impeding energy density enhancement and causing a drastic decline in efficiency because of the incompatibility between filler–matrix interfaces. Herein, organic molecular triptycene (TE) was used as a filler to fabricate poly(vinylidene fluoride) (PVDF)-based composites. The introduction of TE significantly improved the crystallization characteristics, including crystallite size and crystallinity, avoiding the disadvantages of ceramic fillers and leading to increased breakdown strength and dielectric constant. PVDF/TE composites exhibited significant improvements in dielectric properties. The PVDF–15 wt% TE achieved a breakdown strength of 555 MV m⁻¹ and an energy density of 17.33 J cm⁻³, with an efficiency of ∼74%, which was 2.81 times greater than that of pristine PVDF.