Dielectric and energy storage behavior of PVDF composite film filled with graphene quantum dots decorated BaTiO3

High performance dielectric storage films are widely applicated in the high technology field like new energy vehicles, wind turbine generators, avionic industries, oil and gas explorations etc. To improve the energy storage density of the dielectric films, achieving high electric breakdown strength and permittivity are required. In this study, we designed a hybrid that the graphene quantum dots are deposited on the surface of BaTiO₃ particles (denoted as BT@GQDs) as fillers in the PVDF films. The results show that the GQDs has the function of enhancing the polarization of the composites. Higher permittivity and displacement of the BT@GQDs/PVDF composites were observed than that of the BT/PVDF composites. Meanwhile, high electric breakdown strength was achieved for the BT@GQDs/PVDF composites. Hence, the energy storage density of the composites was significantly improved. A high energy storage density of 13.6 J/cm³, which is 197% of the pure PVDF films, was obtained for the BT@GQDs/PVDF composites filled with 3 wt% BT@GQDs.