Boosting Piezoelectric Performance of Poly(vinylidene fluoride) through Synchronizing Intense Shear and Ion–Dipole Interaction under Microinjection Molding

Due to the outstanding flexibility and stress-to-electricity conversion characteristics, piezoelectric polymer devices are increasingly emerging as ideal power supply solutions for self-powered intelligent devices. In addition, achieving piezoelectric polar active crystals via conventional processing methods still remains challenging, thus severely constraining the output performance. Herein, we successfully developed a novel polyvinylidene fluoride (PVDF)/cetyltrimethylammonium bromide (CTAB) piezoelectric composite that achieves boosted piezoelectric performance and conversion efficiency through combining the intense shear force field of microinjection molding with the strong ion-dipole interaction. The mechanism underlying the influence of the macroscopic intense shear flow field and microscopic interface coupling on the crystal structure, crystal morphology, and electrical properties of the resulting PVDF composite was thoroughly investigated. The content of the obtained polar active crystals (β and γ) could achieve as high as 77.2% under the controlled conditions. The enhanced piezoelectric properties could reach an open-circuit voltage of 3.7 V and a short-circuit current of 131.5 nA, respectively, which were better than those of most reported piezoelectric materials. This work not only contributed a new route to induce the generation of polar crystals in piezoelectric polymers but also offered a promising approach for large-scale production of high-performance piezoelectric devices.