A highly dense structure boosts energy harvesting and cycling reliabilities of a high-performance lead-free energy harvester

Abstract

Currently, effective piezoelectric energy harvesters are based on Pb(Zr,Ti)O₃ (PZT) ceramics. However, the growing environmental concerns have been pushing the development of viable green alternatives for lead-based piezoelectric ceramics. In this study, a high quality Mn-modified (K_0.5Na_0.5)NbO₃ (Mn-KNN) lead-free piezoelectric ceramic has been prepared, which is promising for use in lead-free piezoelectric energy harvesters. Herein, we showed that the 1.0 mol% Mn-KNN ceramics not only possessed high Curie temperature, but also exhibited excellent energy harvesting performance due to the highly dense fine-grained structure and various domain configurations. In the mode of a cantilever-type energy harvester, a high output power of 85 μW and peak-to-peak voltage of 16 V were obtained at the acceleration of 40 m s⁻². Furthermore, the 1.0 mol% Mn-KNN energy harvester exhibits excellent fatigue resistance up to 10⁶ cycles. These findings indicate potential applications of the Mn-KNN piezoelectric energy harvester for self-powered sources of wireless sensor network systems.