Piezoelectric nanogenerators (PENGs) with good flexibility and high outputs have promising applications in harvesting mechanical energy and powering electronics. In this study, a synthesis of hierarchical BaTiO3 flowers (BTFs) and their filling into the polydimethylsiloxane (PDMS) matrix to obtain composites with excellent energy harvesting properties is reported. The BTF‐based PENG possesses a voltage of 260 V, a current of 50 µA, and a power of 1728 µW under a compression of 50 N at 3.5 Hz, which output power is two orders higher than that of polymer composites filled with BT nanoparticles. Simulation indicates that the high local stress at petals of BTFs is the main reason for the enhanced performances. The PENG shows good durability under 5000 cycles and lights up 58 commercial light emitting diodes and a display. The PENG generates 30–100 V in harvesting human motions of hand slapping and foot stepping and ≈50 V in harvesting the sport kinetic energy of basketball bouncing. This research presents a BTF‐based PENG with significantly enhanced energy harvesting performances for applications in micro/nanoenergy systems.

In this study, a flower-like TiO₂ filled polymethyl methacrylate (PMMA) composite is presented as a positive tribo-material to produce an excellent-performance triboelectric nanogenerator (TENG).

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Dielectric substances exhibit great potential for high-power capacitors due to their high stability and fast charge–discharge; however, a long-term challenge is to enhance energy density. Here, we propose a poly(vinylidene fluoride) (PVDF) composite utilizing BaTiO3 nanoparticle@TiO2 nanosheet (BT@TO ns) 2D nanohybrids as fillers, aiming at combining the interfacial strategy of using a core–shell filler and the electron scattering of a 2D filler to improve the energy density. With 4 wt% filler, the composite possesses the largest breakdown strength (Eb) of 561.2 MV m−1, which is significantly enhanced from the 407.6 MV m−1 of PVDF, and permittivity of 12.6 at 1 kHz, which is a 23% increase from that of PVDF. A superhigh energy density of 21.3 J cm−3 with an efficiency of 61% is obtained at 550 MV m−1. The 2D BT@TO ns-filled composite exhibits a higher energy density than composites filled with core–shell 1D BT@TO nws or non-core–shell 0D BT, 1D TO, or 2D TO particles. The Eb and energy density improvements are attributed to the buffer layer-based interface engineering and enhanced area scattering of electrons caused by the 2D hybrids, an effect similar to that of a ping-pong paddle to scatter electric field-induced charge migrations in composites. Thus, an effective hybrid strategy is presented for achieving high-performance polymer composites that can be used in energy storage devices.

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