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 β-phase and interfacial polarization, which can improve the permittivity ( ε r ) of nanocomposites. Meanwhile, the shape of 2D TNSs plays an important role in enhancement of breakdown strength ( E b ). The ε 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 (~0.25 J/cm 3 ). The energy efficiency of this typical nanocomposite is similar as that of pure PVDF (~90%). This work might provide a method of fabricating promising energy storage dielectric materials.