Polymer film capacitors have been widely applied in many pulsed power fields owing to their fastest energy-released rates. The development of ferroelectric polyvinylidene fluoride (PVDF)-based composites has become one of the hot research directions in the field of high-energy storage capacitors. Recently, hierarchically-structured all-organic composites have been shown to possess excellent comprehensive energy storage performance and great potential for application. In this review, most research advances of hierarchically-structured all-organic composites for the energy storage application are systematically classified and summarized. The regulating strategies of hierarchically structured all-organic composites are highlighted from the perspective of preparation approaches, tailored material choices, layer thicknesses, and interfaces. Systematic comparisons of energy storage abilities are presented, including electric displacement, breakdown strength, energy storage density, and efficiency. Finally, we present the remaining problems of hierarchically structured all-organic composites and provide an outlook for future energy storage applications.

Dielectric nanocomposites with high energy storage density (U_e) have a strong attraction to high-pulse film energy-storage capacitors. Nevertheless, low breakdown strengths (E_b) and electric displacement difference (D_max-D_rem) values of nanocomposites with incorporating the randomly distributed high dielectric constant additions, give rise to low U_e, thereby hindering the development of energy-storage capacitors. In this study, we report on newly designed SrTiO₃@SiO₂ platelets/PVDF textured composites with excellent capacitive energy storage performance. SrTiO₃@SiO₂ platelets are well oriented in the PVDF when perpendicular to the electric field with the assistance of shear force in the flow drawing process to establish microscopic barriers in an inorganic–polymer composite that is able to substantially improve the E_b of composites and enhance the U_e accordingly. Finite element simulation demonstrates that the introduction of the highly insulating SiO₂ coating onto the SrTiO₃ platelets effectively alleviates the interface dielectric mismatch between filler and PVDF matrix, resulting in a reduction in the interface electric field distortion. The obtained composite film with optimized paraelectric SrTiO₃@SiO₂ platelets (1 vol%) exhibited a maximum D_max-D_rem value of 9.14 μC cm⁻² and a maximum U_e value of 14.4 J cm⁻³ at enhanced E_b of 402 MV m⁻¹, which are significantly superior to neat PVDF and existing dielectric nanocomposites.