Giant Piezoelectric Output and Stability Enhancement in Piezopolymer Composites with Liquid Metal Nanofillers

Abstract Integrating nanomaterials into the polymer matrix is an effective strategy to optimize the performance of polymer‐based piezoelectric devices. Nevertheless, the trade‐off between the output enhancement and stability maintenance of piezoelectric composites usually leads to an unsatisfied overall performance for the high‐strength operation of devices. Here, by setting liquid metal (LM) nanodroplets as the nanofillers in a poly(vinylidene difluoride) (PVDF) matrix, the as‐formed liquid‐solid/conductive‐dielectric interfaces significantly promote the piezoelectric output and the reliability of this piezoelectric composite. A giant performance improvement featured is obtained with, nearly 1000% boosting on the output voltage (as high as 212 V), 270% increment on the piezoelectric coefficient ( d 33 ∼51.1 pC N −1 ) and long‐term reliability on both structure and output (over 36 000 cycles). The design of a novel heterogenous interface with both mechanical matching and electric coupling can be the new orientation for developing high performance piezoelectric composite‐based devices.