High-performance flexible piezoelectric nanogenerator with folded structure based on CNTs-modified BCZT/P(VDF-HFP) composite film

With the energy shortage and the increasing awareness of environmental protection, piezoelectric nanogenerator (PENG) has been widely studied in recent years. Polyvinylidene fluoride hexafluoropropylene (P(VDF- HFP)) is an ideal matrix material because of its piezoelectricity, flexibility, and toughness. Herein, a composite film of carbon nanotubes (CNTs), Ba0.85Ca0.15Zr0.10Ti0.90O3 (BCZT), and P(VDF-HFP) (CNTs/BCZT/P(VDF-HFP)) were prepared via the tape casting method. Adding BCZT increased the polar beta-phase in P(VDF-HFP), reaching a maximum when 40 wt% BCZT was incorporated. Adding CNTs to the matrix provides a conductive path inside the composite. The CNTs/BCZT/P(VDF-HFP) composite film demonstrated optimal electrical properties when 0.3 wt% CNTs is doped, with the open circuit voltage increased from 22 to 30 V and the short circuit current increased from 3 to 5.9 mu A compared with the undoped sample. The output performance of the PENG was further improved with a three-layer folded structure, achieving an open circuit voltage of 40 V and a maximum power density of 31.5 mW m(-2), which easily lit six light-emitting diodes.