Hemispherically Aggregated BaTiO₃ Nanoparticle Composite Thin Film for High-Performance Flexible Piezoelectric Nanogenerator

We report high-performance flexible nanogenerators (NGs) based on a composite thin film, composed of hemispherically aggregated BaTiO₃ nanoparticles (NPs) and poly(vinylidene fluoride-co-hexa­fluoro­propene) P(VDF-HFP). The hemispherical BTO–P(VDF-HFP) clusters were realized by a solvent evaporation method, which greatly enhanced piezoelectric power generation. The flexible NGs exhibit high electrical output up to ∼75 V and ∼15 μA at the applied force normal to the surface, indicating the important role of hemispherical BTO clusters. Besides, the durability and reproducibility of the NGs were tested by cyclic measurement under bending stage, generating the output of ∼5 V and ∼750 nA. The approach we introduce here is simple, cost-effective, and well-suited for large-scale high-performance flexible NG fabrication.