Mechanical‐Dielectric Synergistic Modulation Enables High Energy Density in <scp>TPU</scp> / <scp>PVDF</scp> All‐Organic Films

ABSTRACT This study developed high‐performance thermoplastic polyurethane (TPU)/poly (vinylidene fluoride) (PVDF) all‐organic dielectric films through a mechanical‐dielectric synergistic enhancement mechanism using a simple solution casting method. Results demonstrated that incorporating 3 wt% TPU significantly improved the dielectric properties, achieving a breakdown strength of 543 MV m −1 (67% higher than pure PVDF) and an energy storage density of 7.71 J cm −3 (a 134% enhancement). Mechanical performance tests indicate that the large π‐bonds of the benzene rings in TPU enhance inter‐chain interactions, thereby significantly improving tensile strength, while the tight molecular chain packing arrangement contributes to the enhanced Young's modulus. Under electric field induction, TPU molecular chains actively fill defect sites in the PVDF matrix through dynamic conformational adjustments, suppressing local electric field distortion to reduce charge accumulation and significantly enhance breakdown strength. Moreover, the formation of elastic networks improves the dissipation efficiency of electromechanical stress. This transformation shifts the failure mode from brittle fracture to ductile behavior, resulting in a marked improvement in breakdown strength. This multi‐scale mechanical‐dielectric synergy provides a novel strategy for designing high‐performance flexible electronic devices.