Preparation and enhanced electrical breakdown strength of PVDF-TrFE-CTFE/PVDF-HFP film composites

Abstract Poly(vinylidenefluoride-trifluoroethylenechlorotrifuoroethylene), PVDF-TrFE-CTFE composite films with addition poly(vinylidene fluoride-co-hexafluoropropylene), PVDF-HFP at different copolymer loading was prepared by using the tape casting solution method. Electrical breakdown strength (E b ) was measured by the dielectric breakdown test system and fitting the E b by the Weibull model. The experimental results illustrated that the breakdown probability, P(E) of the neat terpolymer and copolymer film was 316 V/μm and 495 V/μm, respectively. In addition, the breakdown probability of composite films between terpolymer and copolymer is higher than the neat PVDF-TrFE-CTFE film, in which the value of E b is almost double when compared with terpolymer film. We will discuss on their crystallinity, material homogeneity and crystalline size to provide the method to improve the electrical breakdown strength with addition copolymer for energy storage applications.