Study of energy storage of polymer composite Poly(vinylidene fluoride-trifluoroethylene-chlorotrifluoroethylene) (PVDF-TrFE-CTFE)

Abstract

The need of self-powered, flexible battery and capacitance energy storage applications is at the origin of intense research activity on dielectric polymer composites. PVDF family fluoropolymers are potential candidate for capacitance energy storage applications due to their high dielectric constant and breakdown strength (Eb). This work, semi-crystalline copolymer Poly(vinylidene fluoride-co hexafluoropropylene), PVDF-HFP, was fabricated as two phases and three phases with Poly(vinylidenefluoride-trifluoroethylenechlorotrifuoroethylene), PVDF-TrFE-CTFE and Graphene nanoplatelet (GPN). The blend composite films with addition at different filler loading was prepared by using the tape casting solution method. The electrical properties and energy storage capability of two phases and three phases composites was investigated by LCR meter and ferroelectric setup, respectively. Weibull model was used to fitting and characterized Eb, which was measured by the dielectric breakdown test system. The combination between PVDF-HFP and PVDF-TrFE-CTFE induced changing of morphology, Eb, and percentage of crystallinity of composite films. Moreover, GNP fillers increase the interfacial polarization within blend polymer when filler content was increased. At T2C4 blend composite film increase the energy storage density from 14.47 to 29.11 J/cm3 (at 40kV/mm) by GPN loading. The improvement in energy storage capability and Eb might be ascribed to interaction between blend polymer and GPN loading that relate to their energy loss, material homogeneity, and crystalline size. This work provides new designing and promising in high performance dielectric materials for capacitance energy storage applications.