High energy density in PVDF nanocomposites using an optimized nanowire array

TiO 2 nanowire arrays are often utilized to prepare high performance polymer nanocomposites, however, the contribution to the energy density is limited due to their non-ferroelectric characteristics. A nanocomposite with an optimized nanowire array combining the ferroelectric properties of lead zirconate titanate (PZT) with TiO 2 , readily forming nanowires (denoted as a TiO 2 -P nanowire array), is prepared to enhance the permittivity. Poly(vinylidene fluoride) (PVDF) is used as the polymer matrix due to its high breakdown strength, e.g. 600-700 kV mm −1 . As a result, the permittivity and breakdown electric field reach 53 at 1 kHz and 550 kV mm −1 , respectively. Therefore, the nanocomposites achieve a higher discharge energy density of 12.4 J cm −3 with excellent cycle stability, which is the highest among nanocomposites based on a nanowire array as a filler in a PVDF matrix. This work provides not only a feasible approach to obtain high performance dielectric nanocomposites, but also a wide range of potential applications in the energy storage and energy harvesting fields. Introducing PZT as the coating layer of TiO 2 nanowire arrays, the obtained TiO 2 -P/PVDF nanocomposite achieved a high permittivity and breakdown electric field of 53 at 1 kHz and 550 kV mm −1 , respectively, resulting in a higher discharged energy density of 12.4 J cm −3 .