An efficient charge extraction strategy for high-performance piezoelectric nanogenerators via a 3D nanostructured conductive network

Flexible piezoelectric nanogenerators (PENGs) have emerged as a promising technology for energy harvesting and wearable sensing applications. However, their output power is often low due to high inherent impedance and inefficient charge transfer. Herein, an efficient charge extraction strategy is proposed for developing high-performance PENGs by integrating a three-dimensional (3D) nanostructured conductive network within piezoelectric nanofibers. This 3D conductive network, composed of aligned antimony tin oxide (ATO) nanofibers and in situ grown carbon nanotube (CNT) bridges, facilitates internal instantaneous charge transfer and significantly improves the output performance of PENGs. Consequently, the fabricated barium titanate (BaTiO₃) nanofiber-based PENG with the 3D conductive network exhibits a voltage of 64.4 V and a current of 29.4 μA, corresponding to 8.8-fold and 12.7-fold improvements, respectively, compared to a PENG with neat BaTiO₃ nanofibers. Additionally, this versatile charge extraction strategy can be applicable to other piezoelectric materials, such as PbZr_0.52Ti_0.48O₃ and (Ba_0.85Ca_0.15)(Ti_0.9Zr_0.1)O₃ nanofibers, achieving remarkable energy output. The application of the developed PENG has been demonstrated in a wearable emergency communication system, highlighting its ability to achieve high-resolution in signal transmission. This work offers an effective and broadly applicable charge extraction strategy for boosting the output of PENGs, greatly expanding their applications across various domains.