Enhancing output performance of PVDF-HFP fiber-based nanogenerator by hybridizing silver nanowires and perovskite oxide nanocrystals

Abstract

This work presents a new approach for hybridizing nano-scale materials to create Schottky junctions for regulating the dynamic movement of triboelectric charges in the friction layer and enhancing the electrical output of flexible triboelectric nanogenerators (TENGs). The electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite nanofiber mat was used as the tribo-negative layer. By introducing a combination of conductive silver nanowires (AgNWs) and perovskite oxide Mn-doped (Bi0.5Na0.5)TiO3-BaTiO3 (Mn-BNT-BT) nanocrystals into the electrospun PVDF-HFP nanofibers as tribo-negative layer, a significant increase of 386% in the output power over the pristine PVDF-HFP nanogenerator was achieved. For the hybrid TENG with 5% AgNWs and 5% of Mn-BNT-BT nanocrystals, a peak open-circuit voltage of 2170 V and a power density of 47 W/m2 were realized, which are remarkably superior to the output performance of previous PVDF-based TENGs. The key contributing factors include improved dielectric property of the electrospun fiber mat, increased capacitance of the TENG, increased charge trapping capability, and enlarged work function of the composite fiber mat. Schottky junction between semi-conductive perovskite oxide and metal nanowires accelerates the charge movement from AgNWs to PVDF-HFP and slows electron dissipation, retaining a higher and longer lasting potential. The resultant high performance Schottky junction based TENG has high potential to be a renewable, biocompatible, and wearable energy supply for physiological monitoring, human machine interactions, health care in the rapidly evolving information age.