High-Performance Coupled Nanogenerators Based on Electrospun Porous PU@PVDF-ZnO Nanofibers with Core–Shell Structure

With the increasingdemand for sustainable energy harvesting and advanced engineering materials, coupled nanogenerators present promising applications as an emerging energy conversion device. The limitations of conventional materials regarding strength and durability have stimulated the development of novel coupled nanogenerator sutilizing a porous core-shell structured nanofiber architecture: porous polyurethane@polyvinylidene difluoride- zinc oxide* polyamide 66 (porous PU@PVDF-ZnO*PA66). In this study, thefriction-negative and piezoelectric layers were composed of porous PU@PVDF-ZnO,which were fabricated using a cost-effective and straightforward electrospinning technique. This research investigates the impacts of ZnO concentration, surface morphology, contact area, and separation distance on the performance of the nanogenerator. It was determined that the nanogenerator incorporating 10 wt% ZnO yielded the maximum output voltage, short-circuitcurrent, and output power density of 129.3 V, 0.644 μA, and 0.0021 μW/m², respectively. Additionally, it exhibited a mechanical strength of 8.8 MPa andan elongation at break of 196.7%. The nanofiber membrane demonstrated a water contact angle of 104.75° and maintained excellent morphology at 160 °C, with stable output observed after 5000 cycles of contact separation. We posit that coupled nanogenerators, characterized by their flexibility and washability, hold significant promise for applications in wearable electronics, addressing the challenges associated with fabric durability.