Aluminum impregnated zinc oxide engineered poly(vinylidene fluoride hexafluoropropylene)‐based flexible nanocomposite for efficient harvesting of mechanical energy
Shewli Pratihar, Epsita Kar, Shrabanee Sen
Abstract
Confronting the depletion of fossil fuel energy as well as pollution generated from chemical batteries, associated with the increasing number of electronic equipment and the internet of things, results in a high requirement of lightweight, low cost, sustainable, and durable power devices. Currently, a flexible and self-powered piezoelectric energy harvester (PZEH) is a suitable alternative, which may be easily integrated with small electronics to realize real-time sustainable energy generation. Therefore, a novel PZEH has been fabricated at room temperature (30°C) using Al-doped ZnO (Al@ZnO) incorporated poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) nanocomposites. Al@ZnO enables nucleation of electroactive phase within PVDF-HFP (10PALZO) exhibited polarity at a much higher fraction (F[EA] >90%) compared to neat PVDF-HFP (F[EA] = 63.8%). Piezoelectric energy harvesting capability of the device has been investigated under gentle repeated human finger tapping. Optimized Al@ZnO-PVDF-HFP composite (with 10 wt% loading)-based PZEH delivered a high value of open-circuit output voltage ~22 V. Such high output value infers a good energy conversion efficiency of the device. For further enhancement of the performance of the device, the 10PALZO nanocomposite was placed under a high electric field of 2.4 MVcm−1 resulting in an open circuit output voltage of ~26 V. In addition to that, the proposed nanocomposite exhibits a good energy storage efficiency (10PALZO-P) which further enhanced to 111.2 μJcm−3 (at 1 Hz) after poling under an electric field 2.4 MVcm−1. This increment in the output value is due to the improved polarization induced by Al@ZnO within the PVDF-HFP matrix. These results highlight that the filler can efficiently maximize the device performance thereby developing new efficient energy harvesting materials.