Ultrahigh efficiency and energy density in tri-layered ferroelectric polymer composites utilizing ultralow loading of micro-sized plates

Ferroelectric-based composites have demonstrated tremendous potential in electrostatic capacitor owing to their exceptional dielectric characteristics. However, it is extremely challenging to attain desirable energy density () and above 95% efficiency () under low electric fields in the ferroelectric polymer-based composites because of the dominating electrical conduction loss. Herein, ferroelectric polymer composites consisting of SrTiO@SiO plates/(PVDF--HFP) as the inner layer and polycarbonate (PC) as the outer polymer layers are elaborately proposed. The vital role of the multiple interlaminar interfaces (electrode/dielectric interface and interlayer interface) on the reduction of conduction loss and improvement of corresponding energy storage properties of the ferroelectric polymer is verified by experimental and theoretical simulations. The resulting composite with an ultralow loading of SrTiO@SiO plates (0.5 vol%) displays a record high capacitive performance (∼8.73 J/cm) at above 95% under the low electric field of 280 MV/m, indicating an enormous ∼118% increment of the maximal over the commercial bench-mark biaxially oriented polypropylene (∼4 J/cm) and far outperforming those of the polymer-based dielectrics reported to date. Along with fast discharge time (9 ns), this contribution presents a versatile and competitive technology for fabricating composites with exceptional energy storage capabilities operating under low electric fields.