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

Abstract 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), Ba 0.85 Ca 0.15 Zr 0.10 Ti 0.90 O 3 (BCZT), and P(VDF‐HFP) (CNTs/BCZT/P(VDF‐HFP)) were prepared via the tape casting method. Adding BCZT increased the polar β‐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 μA 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.