Enhanced energy storage of polyvinylidene fluoride-based nanocomposites induced by high aspect ratio titania nanosheets

To enhance the discharge energy density (U-e) of polyvinylidene fluoride (PVDF), two-dimensional (2D) titania nanosheets (TNSs) with high aspect ratio were introduced into PVDF. The results show that the TNSs are uniformly dispersed in matrix and the existence of matrix-filler interface is confirmed by small angle X-ray scattering. Introducing of high aspect ratio TNSs is beneficial to enhance the concentration of polar beta-phase and interfacial polarization, which can improve the permittivity (epsilon(r)) of nanocomposites. Meanwhile, the shape of 2D TNSs plays an important role in enhancement of breakdown strength (E-b). The epsilon(r) and E-b of the nanocomposites are two significant factors of their high energy storage performance. Therefore, the U-e increases to 0.32 J/cm(3), which is 28% higher than that of pure PVDF (similar to 0.25 J/cm(3)). The energy efficiency of this typical nanocomposite is similar as that of pure PVDF (similar to 90%). This work might provide a method of fabricating promising energy storage dielectric materials.