Flexible dielectric polymeric films are highly desirable materials with potential applications in power conditioning equipment and pulsed-plasma thrusters due to their high dielectric constant, low dielectric loss, and fast energy uptake and delivery. In this work, 1-3 type nanocomposites combining BaTiO3 nanotubes (BT NTs) and poly(vinylidene fluoride) (PVDF) were prepared by a solution cast method. The BT NTs were synthesized by facile coaxial electrospinning and were coated with a dense and robust dopamine layer, which effectively improved the filler-matrix distributional homogeneity and compatibility. The 10.8 vol% BT-DA NTs/PVDF nanocomposites possessed an excellent dielectric constant of 47.05, which is approximately 569% greater that of the pristine PVDF (8.26) and 150%-350% higher than that of the other PVDF nanocomposites loaded with similar ceramic filler contents, e.g., nanoparticles, nano wires, and nanofibers. The highest energy density of 7.03 J cm(-3) at a relatively low field of 330 MV m(-1) was obtained via small loaded of the fillers, which is approximately 625% greater than for biaxially oriented polypropylenes (BOPP) (1.2 J cm(-3) at the field of 640 MV m(-1)). The approach employed in this study may be further applied to the fabrication of similar polymeric nanocomposites for next-generation electronic components. (C) 2017 Elsevier Ltd. All rights reserved.