Energy harvesting by exploiting the enhanced flexoelectric-like response of reduced (Na0.5Bi0.5)(0.92)Ba0.08TiO3 ceramics

By exploiting the flexoelectric effect, flexoelectric piezoelectric composites (or piezoelectric metamaterials) with a high-temperature-stable piezoelectric response can be designed, but the practical applications of these materials have rarely been explored. We show that after the reduction, the flexoelectric (or flexoelectric-like) response of Na0.5Bi0.5TiO3-based ferroelectric ceramics can be enhanced by 100 times, and the materials exhibit a high apparent piezoelectric response even at a temperature above the depolarization temperature (T-d) of the materials. The performance of the reduced ceramics as an energy harvester was evaluated, especially at a temperature above T-d. We found that the chemical reduction enhanced the output power of the ceramics above T-d by more than 100 times. Although the performance of the flexoelectric energy harvester is inferior to that of conventional piezoelectric harvester below T-d, flexoelectric harvester based on the reduced NBBT8 ceramics provides an approach to harvest the mechanical energy above T-d.