Enhanced breakdown strength and energy density of multilayered P (VDF-HFP)/Nd-doped BaTiO3 nanofibers composites

Flexible dielectric materials with benign energy storage performance are highly desirable for the miniaturization, portability and integration of modern electronics. However, the limited energy storage density seriously restricts their practical applications. Herein, multilayered composite films composed of the P(VDF-HFP) matrix and Nd doped BaTiO3 nanofibers with various filling ratios, layer numbers and topological structures were systematically designed and constructed via the layer-by-layer non-equilibrium process. The 3-layered composite films (3.0 wt% filling ratio) with the pure P(VDF-HFP) layer adjacent to the electrodes revealed good mechanical behavior, greatly enhanced captured ions at interfacial regions and suppressed injected charges from electrodes, which facilitated the improvement of the breakdown strength and discharged energy density. And a maximum Ue of 25.5 J/cm3 with a Eb of 719.9 MV/m was achieved, which was not only 1.4 times more than the pure P(VDFHFP) via the same process, but also behaved better than counterparts with the similar filling ratios and was among the top Ue values of related P(VDF-HFP)-based nanocomposites.